diff options
Diffstat (limited to 'erts/emulator/nifs')
-rw-r--r-- | erts/emulator/nifs/common/prim_buffer_nif.c | 512 | ||||
-rw-r--r-- | erts/emulator/nifs/common/prim_file_nif.c | 1237 | ||||
-rw-r--r-- | erts/emulator/nifs/common/prim_file_nif.h | 240 | ||||
-rw-r--r-- | erts/emulator/nifs/unix/unix_prim_file.c | 957 | ||||
-rw-r--r-- | erts/emulator/nifs/win32/win_prim_file.c | 1427 |
5 files changed, 4373 insertions, 0 deletions
diff --git a/erts/emulator/nifs/common/prim_buffer_nif.c b/erts/emulator/nifs/common/prim_buffer_nif.c new file mode 100644 index 0000000000..a8ef5fc355 --- /dev/null +++ b/erts/emulator/nifs/common/prim_buffer_nif.c @@ -0,0 +1,512 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson 2017. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +#define STATIC_ERLANG_NIF 1 + +#include "erl_nif.h" +#include "config.h" +#include "sys.h" + +#ifdef VALGRIND +# include <valgrind/memcheck.h> +#endif + +#define ACCUMULATOR_SIZE (2 << 10) + +#define FIND_NIF_RESCHEDULE_SIZE (1 << 20) + +/* NIF interface declarations */ +static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info); +static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info); +static void unload(ErlNifEnv *env, void* priv_data); + +static ErlNifResourceType *rtype_buffer; + +static ERL_NIF_TERM am_ok; +static ERL_NIF_TERM am_error; + +static ERL_NIF_TERM am_lock_order_violation; + +static ERL_NIF_TERM am_acquired; +static ERL_NIF_TERM am_busy; + +static ERL_NIF_TERM am_continue; + +static ERL_NIF_TERM am_out_of_memory; +static ERL_NIF_TERM am_not_found; + +typedef struct { +#ifdef DEBUG + erts_atomic32_t concurrent_users; +#endif + + ErlNifBinary accumulator; + size_t accumulated_bytes; + int accumulator_present; + + ErlNifIOQueue *queue; + + erts_atomic32_t external_lock; +} buffer_data_t; + +static ERL_NIF_TERM new_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM peek_head_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM skip_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM size_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM write_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM copying_read_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM find_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM trylock_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM unlock_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ErlNifFunc nif_funcs[] = { + {"new", 0, new_nif}, + {"size", 1, size_nif}, + {"peek_head", 1, peek_head_nif}, + {"copying_read", 2, copying_read_nif}, + {"write", 2, write_nif}, + {"skip", 2, skip_nif}, + {"find_byte_index", 2, find_nif}, + {"try_lock", 1, trylock_nif}, + {"unlock", 1, unlock_nif}, +}; + +ERL_NIF_INIT(prim_buffer, nif_funcs, load, NULL, upgrade, unload) + +static void gc_buffer(ErlNifEnv *env, void* data); + +static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info) +{ + am_ok = enif_make_atom(env, "ok"); + am_error = enif_make_atom(env, "error"); + + am_lock_order_violation = enif_make_atom(env, "lock_order_violation"); + am_acquired = enif_make_atom(env, "acquired"); + am_busy = enif_make_atom(env, "busy"); + + am_continue = enif_make_atom(env, "continue"); + + am_out_of_memory = enif_make_atom(env, "out_of_memory"); + am_not_found = enif_make_atom(env, "not_found"); + + rtype_buffer = enif_open_resource_type(env, NULL, "gc_buffer", gc_buffer, + ERL_NIF_RT_CREATE, NULL); + + *priv_data = NULL; + + return 0; +} + +static void unload(ErlNifEnv *env, void* priv_data) +{ + +} + +static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info) +{ + if(*old_priv_data != NULL) { + return -1; /* Don't know how to do that */ + } + + if(*priv_data != NULL) { + return -1; /* Don't know how to do that */ + } + + if(load(env, priv_data, load_info)) { + return -1; + } + + return 0; +} + +static void gc_buffer(ErlNifEnv *env, void* data) { + buffer_data_t *buffer = (buffer_data_t*)data; + + if(buffer->accumulator_present) { + enif_release_binary(&buffer->accumulator); + } + + enif_ioq_destroy(buffer->queue); +} + +static int get_buffer_data(ErlNifEnv *env, ERL_NIF_TERM opaque, buffer_data_t **buffer) { + return enif_get_resource(env, opaque, rtype_buffer, (void **)buffer); +} + +/* Copies a number of bytes from the head of the iovec, skipping "vec_skip" + * vector elements followed by "byte_skip" bytes on the target vector. */ +static void copy_from_iovec(SysIOVec *iovec, int vec_len, int vec_skip, + size_t byte_skip, size_t size, char *data) { + + size_t bytes_copied, skip_offset; + int vec_index; + + skip_offset = byte_skip; + vec_index = vec_skip; + bytes_copied = 0; + + while(bytes_copied < size) { + size_t block_size, copy_size; + char *block_start; + + ASSERT(vec_index < vec_len); + + block_start = (char*)iovec[vec_index].iov_base; + block_size = iovec[vec_index].iov_len; + + copy_size = MIN(size - bytes_copied, block_size - skip_offset); + sys_memcpy(&data[bytes_copied], &block_start[skip_offset], copy_size); + + bytes_copied += copy_size; + skip_offset = 0; + + vec_index++; + } +} + +/* Convenience function for copy_from_iovec over queues. */ +static void copy_from_queue(ErlNifIOQueue *queue, int queue_skip, + size_t byte_skip, size_t size, char *data) { + + SysIOVec *queued_data; + int queue_length; + + queued_data = enif_ioq_peek(queue, &queue_length); + ASSERT(queue_skip < queue_length); + + copy_from_iovec(queued_data, queue_length, queue_skip, byte_skip, size, data); +} + +static int enqueue_write_accumulator(buffer_data_t *buffer) { + ASSERT(!buffer->accumulator_present ^ (buffer->accumulated_bytes > 0)); + + if(buffer->accumulator_present && buffer->accumulated_bytes > 0) { + if(!enif_realloc_binary(&buffer->accumulator, buffer->accumulated_bytes)) { + return 0; + } else if(!enif_ioq_enq_binary(buffer->queue, &buffer->accumulator, 0)) { + return 0; + } + + /* The queue owns the accumulator now. */ + buffer->accumulator_present = 0; + buffer->accumulated_bytes = 0; + } + + return 1; +} + +static int combine_small_writes(buffer_data_t *buffer, ErlNifIOVec *iovec) { + ASSERT(!buffer->accumulator_present ^ (buffer->accumulated_bytes > 0)); + + if(buffer->accumulated_bytes + iovec->size >= ACCUMULATOR_SIZE) { + if(iovec->size >= (ACCUMULATOR_SIZE / 2)) { + return 0; + } + + if(!enqueue_write_accumulator(buffer)) { + return 0; + } + } + + if(!buffer->accumulator_present) { + if(!enif_alloc_binary(ACCUMULATOR_SIZE, &buffer->accumulator)) { + return 0; + } + + buffer->accumulator_present = 1; + } + + copy_from_iovec(iovec->iov, iovec->iovcnt, 0, 0, iovec->size, + (char*)&buffer->accumulator.data[buffer->accumulated_bytes]); + buffer->accumulated_bytes += iovec->size; + + return 1; +} + +/* *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** */ + +static ERL_NIF_TERM new_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + ERL_NIF_TERM result; + + buffer = (buffer_data_t*)enif_alloc_resource(rtype_buffer, sizeof(buffer_data_t)); + buffer->queue = enif_ioq_create(ERL_NIF_IOQ_NORMAL); + + if(buffer->queue != NULL) { +#ifdef DEBUG + erts_atomic32_init_nob(&buffer->concurrent_users, 0); +#endif + erts_atomic32_init_nob(&buffer->external_lock, 0); + + buffer->accumulator_present = 0; + buffer->accumulated_bytes = 0; + + result = enif_make_resource(env, buffer); + } else { + result = enif_raise_exception(env, am_out_of_memory); + } + + enif_release_resource(buffer); + + return result; +} + +static ERL_NIF_TERM size_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + size_t total_size; + + if(argc != 1 || !get_buffer_data(env, argv[0], &buffer)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_inc_read_acqb(&buffer->concurrent_users) == 1); + + total_size = enif_ioq_size(buffer->queue); + + if(buffer->accumulator_present) { + total_size += buffer->accumulated_bytes; + } else { + ASSERT(buffer->accumulated_bytes == 0); + } + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return enif_make_uint64(env, total_size); +} + +static ERL_NIF_TERM copying_read_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + ERL_NIF_TERM result; + unsigned char *data; + Uint64 block_size; + + if(argc != 2 || !get_buffer_data(env, argv[0], &buffer) + || !enif_get_uint64(env, argv[1], &block_size)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_inc_read_acqb(&buffer->concurrent_users) == 1); + + if(!enqueue_write_accumulator(buffer)) { + return enif_raise_exception(env, am_out_of_memory); + } + + if(enif_ioq_size(buffer->queue) < block_size) { + return enif_make_badarg(env); + } + + data = enif_make_new_binary(env, block_size, &result); + + if(block_size > 0) { + copy_from_queue(buffer->queue, 0, 0, block_size, (char*)data); + enif_ioq_deq(buffer->queue, block_size, NULL); + } + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return result; +} + +static ERL_NIF_TERM write_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + ErlNifIOVec vec, *iovec = &vec; + ERL_NIF_TERM tail; + + if(argc != 2 || !get_buffer_data(env, argv[0], &buffer) + || !enif_inspect_iovec(env, 64, argv[1], &tail, &iovec)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_inc_read_acqb(&buffer->concurrent_users) == 1); + + if(!combine_small_writes(buffer, iovec)) { + if(!enqueue_write_accumulator(buffer) || !enif_ioq_enqv(buffer->queue, iovec, 0)) { + return enif_raise_exception(env, am_out_of_memory); + } + } + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + if(!enif_is_empty_list(env, tail)) { + const ERL_NIF_TERM new_argv[2] = {argv[0], tail}; + + return enif_schedule_nif(env, "write", 0, &write_nif, argc, new_argv); + } + + return am_ok; +} + +static ERL_NIF_TERM peek_head_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + ERL_NIF_TERM result; + + if(argc != 1 || !get_buffer_data(env, argv[0], &buffer)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_inc_read_acqb(&buffer->concurrent_users) == 1); + + if(!enqueue_write_accumulator(buffer)) { + return enif_raise_exception(env, am_out_of_memory); + } + + if(!enif_ioq_peek_head(env, buffer->queue, NULL, &result)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return result; +} + +static ERL_NIF_TERM skip_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + Uint64 block_size; + + if(argc != 2 || !get_buffer_data(env, argv[0], &buffer) + || !enif_get_uint64(env, argv[1], &block_size)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_inc_read_acqb(&buffer->concurrent_users) == 1); + + if(!enqueue_write_accumulator(buffer)) { + return enif_raise_exception(env, am_out_of_memory); + } else if(enif_ioq_size(buffer->queue) < block_size) { + return enif_make_badarg(env); + } + + enif_ioq_deq(buffer->queue, block_size, NULL); + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return am_ok; +} + +static ERL_NIF_TERM find_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + int queue_length, queue_index; + SysIOVec *queued_data; + size_t queue_size; + + size_t search_offset; + int needle; + + if(argc != 2 || !get_buffer_data(env, argv[0], &buffer) + || !enif_get_int(env, argv[1], &needle)) { + return enif_make_badarg(env); + } + + ASSERT(erts_atomic32_inc_read_acqb(&buffer->concurrent_users) == 1); + + if(!enqueue_write_accumulator(buffer)) { + return enif_raise_exception(env, am_out_of_memory); + } else if(needle < 0 || needle > 255) { + return enif_make_badarg(env); + } + + queued_data = enif_ioq_peek(buffer->queue, &queue_length); + queue_size = enif_ioq_size(buffer->queue); + queue_index = 0; + + search_offset = 0; + + if(queue_size > (FIND_NIF_RESCHEDULE_SIZE / 100)) { + if(enif_thread_type() == ERL_NIF_THR_NORMAL_SCHEDULER) { + int timeslice_percent; + + if(queue_size >= FIND_NIF_RESCHEDULE_SIZE) { + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return enif_schedule_nif(env, "find", + ERL_NIF_DIRTY_JOB_CPU_BOUND, &find_nif, argc, argv); + } + + timeslice_percent = (queue_size * 100) / FIND_NIF_RESCHEDULE_SIZE; + enif_consume_timeslice(env, timeslice_percent); + } + } + + while(queue_index < queue_length) { + char *needle_address; + char *block_start; + size_t block_size; + + block_start = queued_data[queue_index].iov_base; + block_size = queued_data[queue_index].iov_len; + + needle_address = memchr(block_start, needle, block_size); + + if(needle_address != NULL) { + size_t result = search_offset + (needle_address - block_start); + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return enif_make_tuple2(env, am_ok, enif_make_uint64(env, result)); + } + + search_offset += block_size; + queue_index++; + } + + ASSERT(erts_atomic32_dec_read_relb(&buffer->concurrent_users) == 0); + + return am_not_found; +} + +/* */ + +static ERL_NIF_TERM trylock_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + if(argc != 1 || !get_buffer_data(env, argv[0], &buffer)) { + return enif_make_badarg(env); + } + + if(erts_atomic32_cmpxchg_acqb(&buffer->external_lock, 1, 0) == 0) { + return am_acquired; + } + + return am_busy; +} + +static ERL_NIF_TERM unlock_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + buffer_data_t *buffer; + + if(argc != 1 || !get_buffer_data(env, argv[0], &buffer)) { + return enif_make_badarg(env); + } + + if(erts_atomic32_cmpxchg_relb(&buffer->external_lock, 0, 1) == 0) { + return enif_raise_exception(env, am_lock_order_violation); + } + + return am_ok; +} diff --git a/erts/emulator/nifs/common/prim_file_nif.c b/erts/emulator/nifs/common/prim_file_nif.c new file mode 100644 index 0000000000..6874f41d75 --- /dev/null +++ b/erts/emulator/nifs/common/prim_file_nif.c @@ -0,0 +1,1237 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson 2017. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +#define STATIC_ERLANG_NIF 1 + +#include "erl_nif.h" +#include "config.h" +#include "sys.h" + +#ifdef VALGRIND +# include <valgrind/memcheck.h> +#endif + +#include "erl_driver.h" +#include "prim_file_nif.h" + +/* NIF interface declarations */ +static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info); +static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info); +static void unload(ErlNifEnv *env, void* priv_data); + +static ErlNifResourceType *efile_resource_type; + +static ERL_NIF_TERM am_ok; +static ERL_NIF_TERM am_error; +static ERL_NIF_TERM am_continue; + +static ERL_NIF_TERM am_file_info; + +/* File modes */ +static ERL_NIF_TERM am_read; +static ERL_NIF_TERM am_write; +static ERL_NIF_TERM am_exclusive; +static ERL_NIF_TERM am_append; +static ERL_NIF_TERM am_sync; +static ERL_NIF_TERM am_skip_type_check; + +/* enum efile_access_t; read and write are defined above.*/ +static ERL_NIF_TERM am_read_write; +static ERL_NIF_TERM am_none; + +/* enum efile_advise_t */ +static ERL_NIF_TERM am_normal; +static ERL_NIF_TERM am_random; +static ERL_NIF_TERM am_sequential; +static ERL_NIF_TERM am_will_need; +static ERL_NIF_TERM am_dont_need; +static ERL_NIF_TERM am_no_reuse; + +/* enum efile_filetype_t */ +static ERL_NIF_TERM am_device; +static ERL_NIF_TERM am_directory; +static ERL_NIF_TERM am_regular; +static ERL_NIF_TERM am_symlink; +static ERL_NIF_TERM am_other; + +/* enum efile_seek_t, 'eof' marker. */ +static ERL_NIF_TERM am_bof; +static ERL_NIF_TERM am_cur; +static ERL_NIF_TERM am_eof; + +static ERL_NIF_TERM read_info_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_permissions_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_owner_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_time_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM read_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM list_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM make_hard_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM make_soft_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM rename_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM make_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM del_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM del_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM get_device_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM get_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM set_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM read_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM get_handle_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM altname_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +static ERL_NIF_TERM open_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]); + +/* All file handle operations are passed through a wrapper that handles state + * transitions, marking it as busy during the course of the operation, and + * closing on completion if the owner died in the middle of an operation. + * + * This is pretty ugly but required as there's no way to tell when it's safe to + * asynchronously close a file; the event could have fired just before landing + * in a system call which will fail with EBADF at best or alias a newly opened + * fd at worst. + * + * The old driver got away with enqueueing the close operation on the same + * async queue as all of its other operations, but since dirty schedulers use a + * single global queue there's no natural way to schedule an asynchronous close + * "behind" other operations. + * + * The states may transition as follows: + * + * IDLE -> + * BUSY (file_handle_wrapper) | + * CLOSED (owner_death_callback) + * + * BUSY -> + * IDLE (file_handle_wrapper) + * CLOSED (close_nif_impl) + * CLOSE_PENDING (owner_death_callback) + * + * CLOSE_PENDING -> + * CLOSED (file_handle_wrapper) + */ + +typedef ERL_NIF_TERM (*file_op_impl_t)(efile_data_t *d, ErlNifEnv *env, + int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM file_handle_wrapper(file_op_impl_t operation, ErlNifEnv *env, + int argc, const ERL_NIF_TERM argv[]); + +#define WRAP_FILE_HANDLE_EXPORT(name) \ + static ERL_NIF_TERM name ## _impl (efile_data_t *d, ErlNifEnv *env, \ + int argc, const ERL_NIF_TERM argv[]);\ + static ERL_NIF_TERM name(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { \ + return file_handle_wrapper( name ## _impl , env, argc, argv); \ + } + +WRAP_FILE_HANDLE_EXPORT(close_nif) +WRAP_FILE_HANDLE_EXPORT(read_nif) +WRAP_FILE_HANDLE_EXPORT(write_nif) +WRAP_FILE_HANDLE_EXPORT(pread_nif) +WRAP_FILE_HANDLE_EXPORT(pwrite_nif) +WRAP_FILE_HANDLE_EXPORT(seek_nif) +WRAP_FILE_HANDLE_EXPORT(sync_nif) +WRAP_FILE_HANDLE_EXPORT(truncate_nif) +WRAP_FILE_HANDLE_EXPORT(allocate_nif) +WRAP_FILE_HANDLE_EXPORT(advise_nif) +WRAP_FILE_HANDLE_EXPORT(get_handle_nif) +WRAP_FILE_HANDLE_EXPORT(ipread_s32bu_p32bu_nif) + +static ErlNifFunc nif_funcs[] = { + /* File handle ops */ + {"open_nif", 2, open_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"close_nif", 1, close_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_nif", 2, read_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"write_nif", 2, write_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"pread_nif", 3, pread_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"pwrite_nif", 3, pwrite_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"seek_nif", 3, seek_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"sync_nif", 2, sync_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"truncate_nif", 1, truncate_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"allocate_nif", 3, allocate_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"advise_nif", 4, advise_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + + /* Filesystem ops */ + {"make_hard_link_nif", 2, make_hard_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"make_soft_link_nif", 2, make_soft_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"rename_nif", 2, rename_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_info_nif", 2, read_info_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_permissions_nif", 2, set_permissions_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_owner_nif", 3, set_owner_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_time_nif", 4, set_time_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_link_nif", 1, read_link_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"list_dir_nif", 1, list_dir_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"make_dir_nif", 1, make_dir_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"del_file_nif", 1, del_file_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"del_dir_nif", 1, del_dir_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"get_device_cwd_nif", 1, get_device_cwd_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"set_cwd_nif", 1, set_cwd_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"get_cwd_nif", 0, get_cwd_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + + /* These operations are equivalent to chained calls of other operations, + * but have been moved down to avoid excessive rescheduling. */ + {"ipread_s32bu_p32bu_nif", 3, ipread_s32bu_p32bu_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + {"read_file_nif", 1, read_file_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, + + /* Internal ops. */ + {"get_handle_nif", 1, get_handle_nif}, + {"altname_nif", 1, altname_nif, ERL_NIF_DIRTY_JOB_IO_BOUND}, +}; + +ERL_NIF_INIT(prim_file, nif_funcs, load, NULL, upgrade, unload) + +static void owner_death_callback(ErlNifEnv* env, void* obj, ErlNifPid* pid, ErlNifMonitor* mon); +static void gc_callback(ErlNifEnv *env, void* data); + +static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info) +{ + ErlNifResourceTypeInit callbacks; + + am_ok = enif_make_atom(env, "ok"); + am_error = enif_make_atom(env, "error"); + am_continue = enif_make_atom(env, "continue"); + + am_read = enif_make_atom(env, "read"); + am_write = enif_make_atom(env, "write"); + am_exclusive = enif_make_atom(env, "exclusive"); + am_append = enif_make_atom(env, "append"); + am_sync = enif_make_atom(env, "sync"); + am_skip_type_check = enif_make_atom(env, "skip_type_check"); + + am_read_write = enif_make_atom(env, "read_write"); + am_none = enif_make_atom(env, "none"); + + am_normal = enif_make_atom(env, "normal"); + am_random = enif_make_atom(env, "random"); + am_sequential = enif_make_atom(env, "sequential"); + am_will_need = enif_make_atom(env, "will_need"); + am_dont_need = enif_make_atom(env, "dont_need"); + am_no_reuse = enif_make_atom(env, "no_reuse"); + + am_device = enif_make_atom(env, "device"); + am_directory = enif_make_atom(env, "directory"); + am_regular = enif_make_atom(env, "regular"); + am_symlink = enif_make_atom(env, "symlink"); + am_other = enif_make_atom(env, "other"); + + am_file_info = enif_make_atom(env, "file_info"); + + am_bof = enif_make_atom(env, "bof"); + am_cur = enif_make_atom(env, "cur"); + am_eof = enif_make_atom(env, "eof"); + + callbacks.down = owner_death_callback; + callbacks.dtor = gc_callback; + callbacks.stop = NULL; + + efile_resource_type = enif_open_resource_type_x(env, "efile", &callbacks, + ERL_NIF_RT_CREATE, NULL); + + *priv_data = NULL; + + return 0; +} + +static void unload(ErlNifEnv *env, void* priv_data) +{ + +} + +static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info) +{ + if(*old_priv_data != NULL) { + return -1; /* Don't know how to do that */ + } + if(*priv_data != NULL) { + return -1; /* Don't know how to do that */ + } + if(load(env, priv_data, load_info)) { + return -1; + } + return 0; +} + +static ERL_NIF_TERM posix_error_to_tuple(ErlNifEnv *env, posix_errno_t posix_errno) { + ERL_NIF_TERM error = enif_make_atom(env, erl_errno_id(posix_errno)); + return enif_make_tuple2(env, am_error, error); +} + +static int get_file_data(ErlNifEnv *env, ERL_NIF_TERM opaque, efile_data_t **d) { + return enif_get_resource(env, opaque, efile_resource_type, (void **)d); +} + +static ERL_NIF_TERM file_handle_wrapper(file_op_impl_t operation, ErlNifEnv *env, + int argc, const ERL_NIF_TERM argv[]) { + + efile_data_t *d; + + enum efile_state_t previous_state; + ERL_NIF_TERM result; + + if(argc < 1 || !get_file_data(env, argv[0], &d)) { + return enif_make_badarg(env); + } + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_BUSY, EFILE_STATE_IDLE); + + if(previous_state == EFILE_STATE_IDLE) { + result = operation(d, env, argc - 1, &argv[1]); + + previous_state = erts_atomic32_cmpxchg_relb(&d->state, + EFILE_STATE_IDLE, EFILE_STATE_BUSY); + + ASSERT(previous_state != EFILE_STATE_IDLE); + + if(previous_state == EFILE_STATE_CLOSE_PENDING) { + /* This is the only point where a change from CLOSE_PENDING is + * possible, and we're running synchronously, so we can't race with + * anything else here. */ + erts_atomic32_set_acqb(&d->state, EFILE_STATE_CLOSED); + efile_close(d); + } + } else { + /* CLOSE_PENDING should be impossible at this point since it requires + * a transition from BUSY; the only valid state here is CLOSED. */ + ASSERT(previous_state == EFILE_STATE_CLOSED); + + result = posix_error_to_tuple(env, EINVAL); + } + + return result; +} + +static void owner_death_callback(ErlNifEnv* env, void* obj, ErlNifPid* pid, ErlNifMonitor* mon) { + efile_data_t *d = (efile_data_t*)obj; + + (void)env; + (void)pid; + (void)mon; + + for(;;) { + enum efile_state_t previous_state; + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_CLOSED, EFILE_STATE_IDLE); + + switch(previous_state) { + case EFILE_STATE_IDLE: + efile_close(d); + return; + case EFILE_STATE_CLOSE_PENDING: + case EFILE_STATE_CLOSED: + /* We're either already closed or managed to mark ourselves for + * closure in the previous iteration. */ + return; + case EFILE_STATE_BUSY: + /* Schedule ourselves to be closed once the current operation + * finishes, retrying the [IDLE -> CLOSED] transition in case we + * narrowly passed the [BUSY -> IDLE] one. */ + erts_atomic32_cmpxchg_nob(&d->state, + EFILE_STATE_CLOSE_PENDING, EFILE_STATE_BUSY); + break; + } + } +} + +static void gc_callback(ErlNifEnv *env, void* data) { + efile_data_t *d = (efile_data_t*)data; + + enum efile_state_t previous_state; + + (void)env; + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_CLOSED, EFILE_STATE_IDLE); + + ASSERT(previous_state != EFILE_STATE_CLOSE_PENDING && + previous_state != EFILE_STATE_BUSY); + + if(previous_state == EFILE_STATE_IDLE) { + efile_close(d); + } +} + +static ERL_NIF_TERM efile_filetype_to_atom(enum efile_filetype_t type) { + switch(type) { + case EFILE_FILETYPE_DEVICE: return am_device; + case EFILE_FILETYPE_DIRECTORY: return am_directory; + case EFILE_FILETYPE_REGULAR: return am_regular; + case EFILE_FILETYPE_SYMLINK: return am_symlink; + case EFILE_FILETYPE_OTHER: return am_other; + } + + return am_other; +} + +static ERL_NIF_TERM efile_access_to_atom(enum efile_access_t type) { + if(type & EFILE_ACCESS_READ && !(type & EFILE_ACCESS_WRITE)) { + return am_read; + } else if(type & EFILE_ACCESS_WRITE && !(type & EFILE_ACCESS_READ)) { + return am_write; + } else if(type & EFILE_ACCESS_READ_WRITE) { + return am_read_write; + } + + return am_none; +} + +static enum efile_modes_t efile_translate_modelist(ErlNifEnv *env, ERL_NIF_TERM list) { + enum efile_modes_t modes; + ERL_NIF_TERM head, tail; + + modes = 0; + + while(enif_get_list_cell(env, list, &head, &tail)) { + if(enif_is_identical(head, am_read)) { + modes |= EFILE_MODE_READ; + } else if(enif_is_identical(head, am_write)) { + modes |= EFILE_MODE_WRITE; + } else if(enif_is_identical(head, am_exclusive)) { + modes |= EFILE_MODE_EXCLUSIVE; + } else if(enif_is_identical(head, am_append)) { + modes |= EFILE_MODE_APPEND; + } else if(enif_is_identical(head, am_sync)) { + modes |= EFILE_MODE_SYNC; + } else if(enif_is_identical(head, am_skip_type_check)) { + modes |= EFILE_MODE_SKIP_TYPE_CHECK; + } else { + /* Modes like 'raw', 'ram', 'delayed_writes' etc are handled + * further up the chain. */ + } + + list = tail; + } + + if(modes & (EFILE_MODE_APPEND | EFILE_MODE_EXCLUSIVE)) { + /* 'append' and 'exclusive' are documented as "open for writing." */ + modes |= EFILE_MODE_WRITE; + } else if(!(modes & EFILE_MODE_READ_WRITE)) { + /* Defaulting to read if !(W|R) is undocumented, but specifically + * tested against in file_SUITE. */ + modes |= EFILE_MODE_READ; + } + + return modes; +} + +static ERL_NIF_TERM open_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + efile_data_t *d; + + ErlNifPid controlling_process; + enum efile_modes_t modes; + ERL_NIF_TERM result; + efile_path_t path; + + if(argc != 2 || !enif_is_list(env, argv[1])) { + return enif_make_badarg(env); + } + + modes = efile_translate_modelist(env, argv[1]); + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_open(&path, modes, efile_resource_type, &d))) { + return posix_error_to_tuple(env, posix_errno); + } + + result = enif_make_resource(env, d); + enif_release_resource(d); + + enif_self(env, &controlling_process); + + if(enif_monitor_process(env, d, &controlling_process, &d->monitor)) { + return posix_error_to_tuple(env, EINVAL); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM close_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + enum efile_state_t previous_state; + + if(argc != 0) { + return enif_make_badarg(env); + } + + previous_state = erts_atomic32_cmpxchg_acqb(&d->state, + EFILE_STATE_CLOSED, EFILE_STATE_BUSY); + + ASSERT(previous_state == EFILE_STATE_CLOSE_PENDING || + previous_state == EFILE_STATE_BUSY); + + if(previous_state == EFILE_STATE_BUSY) { + enif_demonitor_process(env, d, &d->monitor); + + if(!efile_close(d)) { + return posix_error_to_tuple(env, d->posix_errno); + } + } + + return am_ok; +} + +static ERL_NIF_TERM read_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 bytes_read, block_size; + SysIOVec read_vec[1]; + ErlNifBinary result; + + if(argc != 1 || !enif_is_number(env, argv[0])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &block_size) || block_size < 0) { + return posix_error_to_tuple(env, EINVAL); + } + + if(!enif_alloc_binary(block_size, &result)) { + return posix_error_to_tuple(env, ENOMEM); + } + + read_vec[0].iov_base = result.data; + read_vec[0].iov_len = result.size; + + bytes_read = efile_readv(d, read_vec, 1); + ASSERT(bytes_read <= block_size); + + if(bytes_read < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read == 0) { + enif_release_binary(&result); + return am_eof; + } + + if(bytes_read < block_size && !enif_realloc_binary(&result, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink read result."); + } + + return enif_make_tuple2(env, am_ok, enif_make_binary(env, &result)); +} + +static ERL_NIF_TERM write_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + ErlNifIOVec vec, *input = &vec; + Sint64 bytes_written; + ERL_NIF_TERM tail; + + if(argc != 1 || !enif_inspect_iovec(env, 64, argv[0], &tail, &input)) { + return enif_make_badarg(env); + } + + bytes_written = efile_writev(d, input->iov, input->iovcnt); + + if(bytes_written < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } + + if(!enif_is_empty_list(env, tail)) { + ASSERT(bytes_written > 0); + return enif_make_tuple2(env, am_continue, tail); + } + + return am_ok; +} + +static ERL_NIF_TERM pread_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 bytes_read, block_size, offset; + SysIOVec read_vec[1]; + ErlNifBinary result; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || + !enif_get_int64(env, argv[1], &block_size) || + (offset < 0 || block_size < 0)) { + return posix_error_to_tuple(env, EINVAL); + } + + if(!enif_alloc_binary(block_size, &result)) { + return posix_error_to_tuple(env, ENOMEM); + } + + read_vec[0].iov_base = result.data; + read_vec[0].iov_len = result.size; + + bytes_read = efile_preadv(d, offset, read_vec, 1); + + if(bytes_read < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read == 0) { + enif_release_binary(&result); + return am_eof; + } + + if(bytes_read < block_size && !enif_realloc_binary(&result, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink pread result."); + } + + return enif_make_tuple2(env, am_ok, enif_make_binary(env, &result)); +} + +static ERL_NIF_TERM pwrite_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + ErlNifIOVec vec, *input = &vec; + Sint64 bytes_written, offset; + ERL_NIF_TERM tail; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_inspect_iovec(env, 64, argv[1], &tail, &input)) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || offset < 0) { + return posix_error_to_tuple(env, EINVAL); + } + + bytes_written = efile_pwritev(d, offset, input->iov, input->iovcnt); + + if(bytes_written < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } + + if(!enif_is_empty_list(env, tail)) { + ASSERT(bytes_written > 0); + return enif_make_tuple3(env, am_continue, + enif_make_int64(env, bytes_written), tail); + } + + return am_ok; +} + +static ERL_NIF_TERM seek_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 new_position, offset; + enum efile_seek_t seek; + + if(argc != 2 || !enif_get_int64(env, argv[1], &offset)) { + return enif_make_badarg(env); + } + + if(enif_is_identical(argv[0], am_bof)) { + seek = EFILE_SEEK_BOF; + } else if(enif_is_identical(argv[0], am_cur)) { + seek = EFILE_SEEK_CUR; + } else if(enif_is_identical(argv[0], am_eof)) { + seek = EFILE_SEEK_EOF; + } else { + return enif_make_badarg(env); + } + + if(!efile_seek(d, seek, offset, &new_position)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return enif_make_tuple2(env, am_ok, enif_make_uint64(env, new_position)); +} + +static ERL_NIF_TERM sync_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + int data_only; + + if(argc != 1 || !enif_get_int(env, argv[0], &data_only)) { + return enif_make_badarg(env); + } + + if(!efile_sync(d, data_only)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM truncate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + if(argc != 0) { + return enif_make_badarg(env); + } + + if(!efile_truncate(d)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM allocate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 offset, length; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || + !enif_get_int64(env, argv[1], &length) || + (offset < 0 || length < 0)) { + return posix_error_to_tuple(env, EINVAL); + } + + if(!efile_allocate(d, offset, length)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM advise_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + enum efile_advise_t advise; + Sint64 offset, length; + + if(argc != 3 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + if(!enif_get_int64(env, argv[0], &offset) || + !enif_get_int64(env, argv[1], &length) || + (offset < 0 || length < 0)) { + return posix_error_to_tuple(env, EINVAL); + } + + if(enif_is_identical(argv[2], am_normal)) { + advise = EFILE_ADVISE_NORMAL; + } else if(enif_is_identical(argv[2], am_random)) { + advise = EFILE_ADVISE_RANDOM; + } else if(enif_is_identical(argv[2], am_sequential)) { + advise = EFILE_ADVISE_SEQUENTIAL; + } else if(enif_is_identical(argv[2], am_will_need)) { + advise = EFILE_ADVISE_WILL_NEED; + } else if(enif_is_identical(argv[2], am_dont_need)) { + advise = EFILE_ADVISE_DONT_NEED; + } else if(enif_is_identical(argv[2], am_no_reuse)) { + advise = EFILE_ADVISE_NO_REUSE; + } else { + /* The tests check for EINVAL instead of badarg. Sigh. */ + return posix_error_to_tuple(env, EINVAL); + } + + if(!efile_advise(d, offset, length, advise)) { + return posix_error_to_tuple(env, d->posix_errno); + } + + return am_ok; +} + +/* This undocumented function reads a pointer and then reads the data block + * described by said pointer. It was reverse-engineered from the old + * implementation so while all tests pass it may not be entirely correct. Our + * current understanding is as follows: + * + * Pointer layout: + * + * <<Size:1/integer-unit:32, Offset:1/integer-unit:32>> + * + * Where Offset is the -absolute- address to the data block. + * + * *) If we fail to read the pointer block in its entirety, we return eof. + * *) If the provided max_payload_size is larger than Size, we return eof. + * *) If we fail to read any data whatsoever at Offset, we return + * {ok, {Size, Offset, eof}} + * *) Otherwise, we return {ok, {Size, Offset, Data}}. Note that the size + * of Data may be smaller than Size if we encounter EOF before we could + * read the entire block. + * + * On errors we'll return {error, posix()} regardless of whether they + * happened before or after reading the pointer block. */ +static ERL_NIF_TERM ipread_s32bu_p32bu_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + Sint64 payload_offset, payload_size; + + SysIOVec read_vec[1]; + Sint64 bytes_read; + + ErlNifBinary payload; + + if(argc != 2 || !enif_is_number(env, argv[0]) + || !enif_is_number(env, argv[1])) { + return enif_make_badarg(env); + } + + { + Sint64 max_payload_size, pointer_offset; + unsigned char pointer_block[8]; + + if(!enif_get_int64(env, argv[0], &pointer_offset) || + !enif_get_int64(env, argv[1], &max_payload_size) || + (pointer_offset < 0 || max_payload_size >= 1u << 31)) { + return posix_error_to_tuple(env, EINVAL); + } + + read_vec[0].iov_base = pointer_block; + read_vec[0].iov_len = sizeof(pointer_block); + + bytes_read = efile_preadv(d, pointer_offset, read_vec, 1); + + if(bytes_read < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read < sizeof(pointer_block)) { + return am_eof; + } + + payload_size = (Uint32)get_int32(&pointer_block[0]); + payload_offset = (Uint32)get_int32(&pointer_block[4]); + + if(payload_size > max_payload_size) { + return am_eof; + } + } + + if(!enif_alloc_binary(payload_size, &payload)) { + return posix_error_to_tuple(env, ENOMEM); + } + + read_vec[0].iov_base = payload.data; + read_vec[0].iov_len = payload.size; + + bytes_read = efile_preadv(d, payload_offset, read_vec, 1); + + if(bytes_read < 0) { + return posix_error_to_tuple(env, d->posix_errno); + } else if(bytes_read == 0) { + enif_release_binary(&payload); + + return enif_make_tuple2(env, am_ok, + enif_make_tuple3(env, + enif_make_uint(env, payload_size), + enif_make_uint(env, payload_offset), + am_eof)); + } + + if(bytes_read < payload.size && !enif_realloc_binary(&payload, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink ipread payload."); + } + + return enif_make_tuple2(env, am_ok, + enif_make_tuple3(env, + enif_make_uint(env, payload_size), + enif_make_uint(env, payload_offset), + enif_make_binary(env, &payload))); +} + +static ERL_NIF_TERM get_handle_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + if(argc != 0) { + return enif_make_badarg(env); + } + + return efile_get_handle(env, d); +} + +static ERL_NIF_TERM read_info_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_fileinfo_t info = {0}; + efile_path_t path; + int follow_links; + + if(argc != 2 || !enif_get_int(env, argv[1], &follow_links)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_read_info(&path, follow_links, &info))) { + return posix_error_to_tuple(env, posix_errno); + } + + /* #file_info as declared in file.hrl */ + return enif_make_tuple(env, 14, + am_file_info, + enif_make_uint64(env, info.size), + efile_filetype_to_atom(info.type), + efile_access_to_atom(info.access), + enif_make_int64(env, MAX(EFILE_MIN_FILETIME, info.a_time)), + enif_make_int64(env, MAX(EFILE_MIN_FILETIME, info.m_time)), + enif_make_int64(env, MAX(EFILE_MIN_FILETIME, info.c_time)), + enif_make_uint(env, info.mode), + enif_make_uint(env, info.links), + enif_make_uint(env, info.major_device), + enif_make_uint(env, info.minor_device), + enif_make_uint(env, info.inode), + enif_make_uint(env, info.uid), + enif_make_uint(env, info.gid) + ); +} + +static ERL_NIF_TERM set_permissions_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + Uint32 permissions; + + if(argc != 2 || !enif_get_uint(env, argv[1], &permissions)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_permissions(&path, permissions))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM set_owner_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + Uint32 uid, gid; + + if(argc != 3 || !enif_get_uint(env, argv[1], &uid) + || !enif_get_uint(env, argv[2], &gid)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_owner(&path, uid, gid))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM set_time_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + Sint64 accessed, modified, created; + efile_path_t path; + + if(argc != 4 || !enif_get_int64(env, argv[1], &accessed) + || !enif_get_int64(env, argv[2], &modified) + || !enif_get_int64(env, argv[3], &created)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_time(&path, accessed, modified, created))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM read_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + ERL_NIF_TERM result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_read_link(env, &path, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM list_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + ERL_NIF_TERM result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_list_dir(env, &path, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM rename_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t existing_path, new_path; + + if(argc != 2) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_marshal_path(env, argv[1], &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_rename(&existing_path, &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM make_hard_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t existing_path, new_path; + + if(argc != 2) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_marshal_path(env, argv[1], &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_make_hard_link(&existing_path, &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM make_soft_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t existing_path, new_path; + + if(argc != 2) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_marshal_path(env, argv[1], &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_make_soft_link(&existing_path, &new_path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM make_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_make_dir(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM del_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_del_file(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM del_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_del_dir(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +static ERL_NIF_TERM get_device_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + ERL_NIF_TERM result; + int device_index; + + if(argc != 1 || !enif_get_int(env, argv[0], &device_index)) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_get_device_cwd(env, device_index, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM get_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + ERL_NIF_TERM result; + + if(argc != 0) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_get_cwd(env, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} + +static ERL_NIF_TERM set_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_set_cwd(&path))) { + return posix_error_to_tuple(env, posix_errno); + } + + return am_ok; +} + +/** @brief Reads an entire file into \c result, stopping after \c size bytes or + * EOF. It will read until EOF if size is 0. */ +static posix_errno_t read_file(efile_data_t *d, size_t size, ErlNifBinary *result) { + size_t initial_buffer_size; + ssize_t bytes_read; + + if(size == 0) { + initial_buffer_size = 16 << 10; + } else { + initial_buffer_size = size; + } + + if(!enif_alloc_binary(initial_buffer_size, result)) { + return ENOMEM; + } + + bytes_read = 0; + + for(;;) { + ssize_t block_bytes_read; + SysIOVec read_vec[1]; + + read_vec[0].iov_base = result->data + bytes_read; + read_vec[0].iov_len = result->size - bytes_read; + + block_bytes_read = efile_readv(d, read_vec, 1); + + if(block_bytes_read < 0) { + enif_release_binary(result); + return d->posix_errno; + } + + bytes_read += block_bytes_read; + + if(block_bytes_read < (result->size - bytes_read)) { + /* EOF */ + break; + } else if(bytes_read == size) { + break; + } + + if(!enif_realloc_binary(result, bytes_read * 2)) { + enif_release_binary(result); + return ENOMEM; + } + } + + /* The file may have shrunk since we queried its size, so we have to do + * this even when the size is known. */ + if(bytes_read < result->size && !enif_realloc_binary(result, bytes_read)) { + ERTS_INTERNAL_ERROR("Failed to shrink read_file result."); + } + + return 0; +} + +static ERL_NIF_TERM read_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_fileinfo_t info = {0}; + efile_path_t path; + efile_data_t *d; + + ErlNifBinary result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_read_info(&path, 1, &info))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_open(&path, EFILE_MODE_READ, efile_resource_type, &d))) { + return posix_error_to_tuple(env, posix_errno); + } + + posix_errno = read_file(d, info.size, &result); + enif_release_resource(d); + + if(posix_errno) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, enif_make_binary(env, &result)); +} + +static ERL_NIF_TERM altname_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) { + posix_errno_t posix_errno; + + efile_path_t path; + ERL_NIF_TERM result; + + if(argc != 1) { + return enif_make_badarg(env); + } + + if((posix_errno = efile_marshal_path(env, argv[0], &path))) { + return posix_error_to_tuple(env, posix_errno); + } else if((posix_errno = efile_altname(env, &path, &result))) { + return posix_error_to_tuple(env, posix_errno); + } + + return enif_make_tuple2(env, am_ok, result); +} diff --git a/erts/emulator/nifs/common/prim_file_nif.h b/erts/emulator/nifs/common/prim_file_nif.h new file mode 100644 index 0000000000..cc9bc8f5c3 --- /dev/null +++ b/erts/emulator/nifs/common/prim_file_nif.h @@ -0,0 +1,240 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson 2017. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +typedef int posix_errno_t; + +enum efile_modes_t { + EFILE_MODE_READ = (1 << 0), + EFILE_MODE_WRITE = (1 << 1), /* Implies truncating file when used alone. */ + EFILE_MODE_APPEND = (1 << 2), + EFILE_MODE_EXCLUSIVE = (1 << 3), + EFILE_MODE_SYNC = (1 << 4), + + EFILE_MODE_SKIP_TYPE_CHECK = (1 << 5), /* Special for device files on Unix. */ + EFILE_MODE_NO_TRUNCATE = (1 << 6), /* Special for reopening on VxWorks. */ + + EFILE_MODE_READ_WRITE = EFILE_MODE_READ | EFILE_MODE_WRITE +}; + +enum efile_access_t { + EFILE_ACCESS_NONE = 0, + EFILE_ACCESS_READ = 1, + EFILE_ACCESS_WRITE = 2, + EFILE_ACCESS_READ_WRITE = EFILE_ACCESS_READ | EFILE_ACCESS_WRITE +}; + +enum efile_seek_t { + EFILE_SEEK_BOF, + EFILE_SEEK_CUR, + EFILE_SEEK_EOF +}; + +enum efile_filetype_t { + EFILE_FILETYPE_DEVICE, + EFILE_FILETYPE_DIRECTORY, + EFILE_FILETYPE_REGULAR, + EFILE_FILETYPE_SYMLINK, + EFILE_FILETYPE_OTHER +}; + +enum efile_advise_t { + EFILE_ADVISE_NORMAL, + EFILE_ADVISE_RANDOM, + EFILE_ADVISE_SEQUENTIAL, + EFILE_ADVISE_WILL_NEED, + EFILE_ADVISE_DONT_NEED, + EFILE_ADVISE_NO_REUSE +}; + +enum efile_state_t { + EFILE_STATE_IDLE = 0, + EFILE_STATE_BUSY = 1, + EFILE_STATE_CLOSE_PENDING = 2, + EFILE_STATE_CLOSED = 3 +}; + +typedef struct { + Sint64 size; /* Size of file */ + Uint32 type; /* Type of file -- one of EFILE_FILETYPE_*. */ + Uint32 access; /* Access to file -- one of EFILE_ACCESS_*. */ + Uint32 mode; /* Access permissions -- bit field. */ + Uint32 links; /* Number of links to file. */ + Uint32 major_device; /* Major device or file system. */ + Uint32 minor_device; /* Minor device (for devices). */ + Uint32 inode; /* Inode number. */ + Uint32 uid; /* User id of owner. */ + Uint32 gid; /* Group id of owner. */ + Sint64 a_time; /* Last time the file was accessed. */ + Sint64 m_time; /* Last time the file was modified. */ + Sint64 c_time; /* Windows: creation time, Unix: last inode + * change. */ +} efile_fileinfo_t; + +/* The smallest value that can be converted freely between universal, local, + * and POSIX time, as required by read_file_info/2. Corresponds to + * {{1902,1,1},{0,0,0}} */ +#define EFILE_MIN_FILETIME -2145916800 + +/* Initializes an efile_data_t; must be used in efile_open on success. */ +#define EFILE_INIT_RESOURCE(__d, __modes) do { \ + erts_atomic32_init_acqb(&(__d)->state, EFILE_STATE_IDLE); \ + (__d)->posix_errno = 0; \ + (__d)->modes = __modes; \ + } while(0) + +typedef struct { + erts_atomic32_t state; + + posix_errno_t posix_errno; + enum efile_modes_t modes; + + ErlNifMonitor monitor; +} efile_data_t; + +typedef ErlNifBinary efile_path_t; + +/* @brief Translates the given "raw name" into the format expected by the APIs + * used by the underlying implementation. The result is transient and does not + * need to be released. + * + * This may change the structure of the path and its results should never be + * passed on to the user. Refer to the OS-specific implementation for details. + * + * @param path The term to translate; it must have been encoded with + * prim_file:internal_native2name for compatibility reasons. */ +posix_errno_t efile_marshal_path(ErlNifEnv *env, ERL_NIF_TERM path, efile_path_t *result); + +/* @brief Returns the underlying handle as an implementation-defined term. + * + * This is an internal function intended to support tests and tricky + * operations like sendfile(2). */ +ERL_NIF_TERM efile_get_handle(ErlNifEnv *env, efile_data_t *d); + +/* @brief Read until EOF or the given iovec has been filled. + * + * @return -1 on failure, or the number of bytes read on success. The return + * value will be 0 if no bytes could be read before EOF or the end of the + * iovec. */ +Sint64 efile_readv(efile_data_t *d, SysIOVec *iov, int iovlen); + +/* @brief Write the entirety of the given iovec. + * + * @return -1 on failure, or the number of bytes written on success. "Partial" + * failures will be reported with -1 and not the number of bytes we managed to + * write to disk before the failure. */ +Sint64 efile_writev(efile_data_t *d, SysIOVec *iov, int iovlen); + +/* @brief As \c efile_readv, but starting from a file offset. */ +Sint64 efile_preadv(efile_data_t *d, Sint64 offset, SysIOVec *iov, int iovlen); + +/* @brief As \c efile_writev, but starting from a file offset. */ +Sint64 efile_pwritev(efile_data_t *d, Sint64 offset, SysIOVec *iov, int iovlen); + +int efile_seek(efile_data_t *d, enum efile_seek_t seek, Sint64 offset, Sint64 *new_position); + +int efile_sync(efile_data_t *d, int data_only); + +int efile_advise(efile_data_t *d, Sint64 offset, Sint64 length, enum efile_advise_t advise); +int efile_allocate(efile_data_t *d, Sint64 offset, Sint64 length); +int efile_truncate(efile_data_t *d); + +posix_errno_t efile_open(const efile_path_t *path, enum efile_modes_t modes, + ErlNifResourceType *nif_type, efile_data_t **d); + +/** @brief Closes a file. The file must have entered the CLOSED state prior to + * calling this to prevent double close. */ +int efile_close(efile_data_t *d); + +/* **** **** **** **** **** **** **** **** **** **** **** **** **** **** **** */ + +posix_errno_t efile_read_info(const efile_path_t *path, int follow_link, efile_fileinfo_t *result); + +/** @brief Sets the file times to the given values. Refer to efile_fileinfo_t + * for a description of each. */ +posix_errno_t efile_set_time(const efile_path_t *path, Sint64 a_time, Sint64 m_time, Sint64 c_time); + +/** @brief On Unix, this sets the file permissions according to the docs for + * file:write_file_info/2. On Windows it uses the "owner write permission" flag + * to toggle whether the file is read-only or not. */ +posix_errno_t efile_set_permissions(const efile_path_t *path, Uint32 permissions); + +/** @brief On Unix, this will set the owner/group to the given values. It will + * do nothing on other platforms. */ +posix_errno_t efile_set_owner(const efile_path_t *path, Uint32 owner, Uint32 group); + +/** @brief Resolves the final path of the given link. */ +posix_errno_t efile_read_link(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result); + +/** @brief Lists the contents of the given directory. + * @param result [out] A list of all the directory/file names contained in the + * given directory. */ +posix_errno_t efile_list_dir(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result); + +/** @brief Changes the name of an existing file or directory, from old_path + * to new_path. + * + * If old_path and new_path refer to the same file or directory, it does + * nothing and returns success. Otherwise if new_path already exists, it will + * be deleted and replaced by src subject to the following conditions: + * + * If old_path is a directory, new_path may be an empty directory. + * If old_path is a file, new_path may be a file. + * + * Neither of these are guaranteed to be atomic. In any other situation where + * new_path already exists, the rename will fail. + * + * Some possible error codes: + * + * - EACCES: Either paths or one of their parent directories can't be read + * and/or written. + * - EEXIST: new_path is a non-empty directory. + * - EINVAL: old_path is a root directory or new_path is a subdirectory + * of new_path. + * - EISDIR: new_path is a directory, but old_path is not. + * - ENOTDIR: old_path is a directory, but new_path is not. + * - ENOENT: old_path doesn't exist, or either path is "". + * - EXDEV: The paths are on different filesystems. + * + * The implementation of rename may allow cross-filesystem renames, + * but the caller should be prepared to emulate it with copy and + * delete if errno is EXDEV. */ +posix_errno_t efile_rename(const efile_path_t *old_path, const efile_path_t *new_path); + +posix_errno_t efile_make_hard_link(const efile_path_t *existing_path, const efile_path_t *new_path); +posix_errno_t efile_make_soft_link(const efile_path_t *existing_path, const efile_path_t *new_path); +posix_errno_t efile_make_dir(const efile_path_t *path); + +posix_errno_t efile_del_file(const efile_path_t *path); +posix_errno_t efile_del_dir(const efile_path_t *path); + +posix_errno_t efile_get_cwd(ErlNifEnv *env, ERL_NIF_TERM *result); +posix_errno_t efile_set_cwd(const efile_path_t *path); + +/** @brief A Windows-specific function for returning the working directory of a + * given device. + * + * @param device_index The drive index; 1 for A, 2 for B, etc. + * @param result [out] The working directory of the given device + */ +posix_errno_t efile_get_device_cwd(ErlNifEnv *env, int device_index, ERL_NIF_TERM *result); + +/** @brief A Windows-specific function for returning the 8.3-name of a given + * file or directory. */ +posix_errno_t efile_altname(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result); diff --git a/erts/emulator/nifs/unix/unix_prim_file.c b/erts/emulator/nifs/unix/unix_prim_file.c new file mode 100644 index 0000000000..57c8ef62e1 --- /dev/null +++ b/erts/emulator/nifs/unix/unix_prim_file.c @@ -0,0 +1,957 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson 2017. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +#include "erl_nif.h" +#include "config.h" +#include "sys.h" + +#ifdef VALGRIND +# include <valgrind/memcheck.h> +#endif + +#include "prim_file_nif.h" + +#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__) +#define __DARWIN__ 1 +#endif + +#if defined(__DARWIN__) || defined(HAVE_LINUX_FALLOC_H) || defined(HAVE_POSIX_FALLOCATE) +#include <fcntl.h> +#endif + +#ifdef HAVE_LINUX_FALLOC_H +#include <linux/falloc.h> +#endif + +#include <utime.h> + +/* Macros for testing file types. */ +#ifdef NO_UMASK +#define FILE_MODE 0644 +#define DIR_MODE 0755 +#else +#define FILE_MODE 0666 +#define DIR_MODE 0777 +#endif + +/* Old platforms might not have IOV_MAX defined. */ +#if !defined(IOV_MAX) && defined(UIO_MAXIOV) +#define IOV_MAX UIO_MAXIOV +#elif !defined(IOV_MAX) +#define IOV_MAX 16 +#endif + +typedef struct { + efile_data_t common; + int fd; +} efile_unix_t; + +static int has_invalid_null_termination(const ErlNifBinary *path) { + const char *null_pos, *end_pos; + + null_pos = memchr(path->data, '\0', path->size); + end_pos = (const char*)&path->data[path->size] - 1; + + if(null_pos == NULL) { + return 1; + } + + /* prim_file:internal_name2native sometimes feeds us data that is "doubly" + * NUL-terminated, so we'll accept any number of trailing NULs so long as + * they aren't interrupted by anything else. */ + while(null_pos < end_pos && (*null_pos) == '\0') { + null_pos++; + } + + return null_pos != end_pos; +} + +posix_errno_t efile_marshal_path(ErlNifEnv *env, ERL_NIF_TERM path, efile_path_t *result) { + if(!enif_inspect_binary(env, path, result)) { + return EINVAL; + } + + if(has_invalid_null_termination(result)) { + return EINVAL; + } + + return 0; +} + +ERL_NIF_TERM efile_get_handle(ErlNifEnv *env, efile_data_t *d) { + efile_unix_t *u = (efile_unix_t*)d; + + ERL_NIF_TERM result; + unsigned char *bits; + + bits = enif_make_new_binary(env, sizeof(u->fd), &result); + memcpy(bits, &u->fd, sizeof(u->fd)); + + return result; +} + +static int open_file_type_check(const efile_path_t *path, int fd) { + struct stat file_info; + int error; + +#ifndef HAVE_FSTAT + error = stat((const char*)path->data, &file_info); + (void)fd; +#else + error = fstat(fd, &file_info); + (void)path; +#endif + + if(error < 0) { + /* If we failed to stat assume success and let the next call handle the + * error. The old driver checked whether the file was to be used + * immediately in a read within the call, but the new implementation + * never does that. */ + return 1; + } else { + /* The old driver tolerated opening /dev/null despite the "no devices" + * limitation. It provided no explanation for this but we still need + * to match the behavior. We're checking through stat(2) instead of + * comparing the name to account for links. */ + struct stat null_device_info; + int is_dev_null; + + is_dev_null = (stat("/dev/null", &null_device_info) == 0); + is_dev_null &= (file_info.st_ino == null_device_info.st_ino); + is_dev_null &= (file_info.st_dev == null_device_info.st_dev); + + if(is_dev_null) { + return 1; + } + } + + if(!S_ISREG(file_info.st_mode)) { + return 0; + } + + return 1; +} + +posix_errno_t efile_open(const efile_path_t *path, enum efile_modes_t modes, + ErlNifResourceType *nif_type, efile_data_t **d) { + + int flags, fd; + + flags = 0; + + if(modes & EFILE_MODE_READ && !(modes & EFILE_MODE_WRITE)) { + flags |= O_RDONLY; + } else if(modes & EFILE_MODE_WRITE && !(modes & EFILE_MODE_READ)) { + if(!(modes & EFILE_MODE_NO_TRUNCATE)) { + flags |= O_TRUNC; + } + + flags |= O_WRONLY | O_CREAT; + } else if(modes & EFILE_MODE_READ_WRITE) { + flags |= O_RDWR | O_CREAT; + } else { + return EINVAL; + } + + if(modes & EFILE_MODE_APPEND) { + flags &= ~O_TRUNC; + flags |= O_APPEND; + } + + if(modes & EFILE_MODE_EXCLUSIVE) { + flags |= O_EXCL; + } + + if(modes & EFILE_MODE_SYNC) { +#ifndef O_SYNC + return ENOTSUP; +#else + flags |= O_SYNC; +#endif + } + + do { + fd = open((const char*)path->data, flags, FILE_MODE); + } while(fd == -1 && errno == EINTR); + + if(fd != -1) { + efile_unix_t *u; + + if(!(modes & EFILE_MODE_SKIP_TYPE_CHECK) && !open_file_type_check(path, fd)) { + close(fd); + + /* This is blatantly incorrect, but we're documented as returning + * this for everything that isn't a file. */ + return EISDIR; + } + + u = (efile_unix_t*)enif_alloc_resource(nif_type, sizeof(efile_unix_t)); + u->fd = fd; + + EFILE_INIT_RESOURCE(&u->common, modes); + (*d) = &u->common; + + return 0; + } + + (*d) = NULL; + return errno; +} + +int efile_close(efile_data_t *d) { + efile_unix_t *u = (efile_unix_t*)d; + int fd; + + ASSERT(erts_atomic32_read_nob(&d->state) == EFILE_STATE_CLOSED); + ASSERT(u->fd != -1); + + fd = u->fd; + u->fd = -1; + + /* close(2) either always closes (*BSD, Linux) or leaves the fd in an + * undefined state (POSIX 2008, Solaris), so we must not retry on EINTR. */ + + if(close(fd) < 0) { + u->common.posix_errno = errno; + return 0; + } + + return 1; +} + +static void shift_iov(SysIOVec **iov, int *iovlen, ssize_t shift) { + SysIOVec *head_vec = (*iov); + + ASSERT(shift >= 0); + + while(shift > 0) { + ASSERT(head_vec < &(*iov)[*iovlen]); + + if(shift < head_vec->iov_len) { + head_vec->iov_base = (char*)head_vec->iov_base + shift; + head_vec->iov_len -= shift; + break; + } else { + shift -= head_vec->iov_len; + head_vec++; + } + } + + (*iovlen) -= head_vec - (*iov); + (*iov) = head_vec; +} + +Sint64 efile_readv(efile_data_t *d, SysIOVec *iov, int iovlen) { + efile_unix_t *u = (efile_unix_t*)d; + + Sint64 bytes_read; + ssize_t result; + + bytes_read = 0; + + do { + int use_fallback = 0; + + if(iovlen < 1) { + result = 0; + break; + } + + /* writev(2) implies readv(2) */ +#ifdef HAVE_WRITEV + result = readv(u->fd, iov, MIN(IOV_MAX, iovlen)); + + /* Fall back to using read(2) if readv(2) reports that the combined + * size of iov is greater than SSIZE_T_MAX. */ + use_fallback = (result < 0 && errno == EINVAL); +#else + use_fallback = 1; +#endif + + if(use_fallback) { + result = read(u->fd, iov->iov_base, iov->iov_len); + } + + if(result > 0) { + shift_iov(&iov, &iovlen, result); + bytes_read += result; + } + } while(result > 0 || (result < 0 && errno == EINTR)); + + u->common.posix_errno = errno; + + if(result == 0 && bytes_read > 0) { + return bytes_read; + } + + return result; +} + +Sint64 efile_writev(efile_data_t *d, SysIOVec *iov, int iovlen) { + efile_unix_t *u = (efile_unix_t*)d; + + Sint64 bytes_written; + ssize_t result; + + bytes_written = 0; + + do { + int use_fallback = 0; + + if(iovlen < 1) { + result = 0; + break; + } + +#ifdef HAVE_WRITEV + result = writev(u->fd, iov, MIN(IOV_MAX, iovlen)); + + /* Fall back to using write(2) if writev(2) reports that the combined + * size of iov is greater than SSIZE_T_MAX. */ + use_fallback = (result < 0 && errno == EINVAL); +#else + use_fallback = 1; +#endif + + if(use_fallback) { + result = write(u->fd, iov->iov_base, iov->iov_len); + } + + if(result > 0) { + shift_iov(&iov, &iovlen, result); + bytes_written += result; + } + } while(result > 0 || (result < 0 && errno == EINTR)); + + u->common.posix_errno = errno; + + if(result == 0 && bytes_written > 0) { + return bytes_written; + } + + return result; +} + +Sint64 efile_preadv(efile_data_t *d, Sint64 offset, SysIOVec *iov, int iovlen) { + efile_unix_t *u = (efile_unix_t*)d; + + Uint64 bytes_read; + Sint64 result; + +#if !defined(HAVE_PREADV) && !defined(HAVE_PREAD) + /* This function is documented as leaving the file position undefined, but + * the old driver always reset it so there's probably code in the wild that + * relies on this behavior. */ + off_t original_position = lseek(u->fd, 0, SEEK_CUR); + + if(original_position < 0 || lseek(u->fd, offset, SEEK_SET) < 0) { + u->common.posix_errno = errno; + return -1; + } +#endif + + bytes_read = 0; + + do { + if(iovlen < 1) { + result = 0; + break; + } + +#if defined(HAVE_PREADV) + result = preadv(u->fd, iov, MIN(IOV_MAX, iovlen), offset); +#elif defined(HAVE_PREAD) + result = pread(u->fd, iov->iov_base, iov->iov_len, offset); +#else + result = read(u->fd, iov->iov_base, iov->iov_len); +#endif + + if(result > 0) { + shift_iov(&iov, &iovlen, result); + bytes_read += result; + offset += result; + } + } while(result > 0 || (result < 0 && errno == EINTR)); + + u->common.posix_errno = errno; + +#if !defined(HAVE_PREADV) && !defined(HAVE_PREAD) + if(result >= 0) { + if(lseek(u->fd, original_position, SEEK_SET) < 0) { + u->common.posix_errno = errno; + return -1; + } + } +#endif + + if(result == 0 && bytes_read > 0) { + return bytes_read; + } + + return result; +} + +Sint64 efile_pwritev(efile_data_t *d, Sint64 offset, SysIOVec *iov, int iovlen) { + efile_unix_t *u = (efile_unix_t*)d; + + Sint64 bytes_written; + ssize_t result; + +#if !defined(HAVE_PWRITEV) && !defined(HAVE_PWRITE) + off_t original_position = lseek(u->fd, 0, SEEK_CUR); + + if(original_position < 0 || lseek(u->fd, offset, SEEK_SET) < 0) { + u->common.posix_errno = errno; + return -1; + } +#endif + + bytes_written = 0; + + do { + if(iovlen < 1) { + result = 0; + break; + } + +#if defined(HAVE_PWRITEV) + result = pwritev(u->fd, iov, MIN(IOV_MAX, iovlen), offset); +#elif defined(HAVE_PWRITE) + result = pwrite(u->fd, iov->iov_base, iov->iov_len, offset); +#else + result = write(u->fd, iov->iov_base, iov->iov_len); +#endif + + if(result > 0) { + shift_iov(&iov, &iovlen, result); + bytes_written += result; + offset += result; + } + } while(result > 0 || (result < 0 && errno == EINTR)); + + u->common.posix_errno = errno; + +#if !defined(HAVE_PWRITEV) && !defined(HAVE_PWRITE) + if(result >= 0) { + if(lseek(u->fd, original_position, SEEK_SET) < 0) { + u->common.posix_errno = errno; + return -1; + } + } +#endif + + if(result == 0 && bytes_written > 0) { + return bytes_written; + } + + return result; +} + +int efile_seek(efile_data_t *d, enum efile_seek_t seek, Sint64 offset, Sint64 *new_position) { + efile_unix_t *u = (efile_unix_t*)d; + off_t result; + int whence; + + switch(seek) { + case EFILE_SEEK_BOF: whence = SEEK_SET; break; + case EFILE_SEEK_CUR: whence = SEEK_CUR; break; + case EFILE_SEEK_EOF: whence = SEEK_END; break; + default: ERTS_INTERNAL_ERROR("Invalid seek parameter"); + } + + result = lseek(u->fd, offset, whence); + + /* + * The man page for lseek (on SunOs 5) says: + * + * "if fildes is a remote file descriptor and offset is negative, lseek() + * returns the file pointer even if it is negative." + */ + if(result < 0 && errno == 0) { + errno = EINVAL; + } + + if(result < 0) { + u->common.posix_errno = errno; + return 0; + } + + (*new_position) = result; + + return 1; +} + +int efile_sync(efile_data_t *d, int data_only) { + efile_unix_t *u = (efile_unix_t*)d; + +#if defined(HAVE_FDATASYNC) && !defined(__DARWIN__) + if(data_only) { + if(fdatasync(u->fd) < 0) { + u->common.posix_errno = errno; + return 0; + } + + return 1; + } +#endif + +#if defined(__DARWIN__) && defined(F_FULLFSYNC) + if(fcntl(u->fd, F_FULLFSYNC) < 0) { +#else + if(fsync(u->fd) < 0) { +#endif + u->common.posix_errno = errno; + return 0; + } + + return 1; +} + +int efile_advise(efile_data_t *d, Sint64 offset, Sint64 length, enum efile_advise_t advise) { + efile_unix_t *u = (efile_unix_t*)d; +#ifdef HAVE_POSIX_FADVISE + int p_advise; + + switch(advise) { + case EFILE_ADVISE_NORMAL: p_advise = POSIX_FADV_NORMAL; break; + case EFILE_ADVISE_RANDOM: p_advise = POSIX_FADV_RANDOM; break; + case EFILE_ADVISE_SEQUENTIAL: p_advise = POSIX_FADV_SEQUENTIAL; break; + case EFILE_ADVISE_WILL_NEED: p_advise = POSIX_FADV_WILLNEED; break; + case EFILE_ADVISE_DONT_NEED: p_advise = POSIX_FADV_DONTNEED; break; + case EFILE_ADVISE_NO_REUSE: p_advise = POSIX_FADV_NOREUSE; break; + default: + u->common.posix_errno = EINVAL; + return 0; + } + + if(posix_fadvise(u->fd, offset, length, p_advise) < 0) { + u->common.posix_errno = errno; + return 0; + } + + return 1; +#else + /* We'll pretend to support this syscall as it's only a recommendation even + * on systems that do support it. */ + return 1; +#endif +} + +int efile_allocate(efile_data_t *d, Sint64 offset, Sint64 length) { + efile_unix_t *u = (efile_unix_t*)d; + int ret = -1; + + /* We prefer OS-specific methods, but fall back to posix_fallocate on + * failure. It's unclear whether this has any practical benefit on + * modern systems, but the old driver did it. */ + +#if defined(HAVE_FALLOCATE) + /* Linux-specific */ + do { + ret = fallocate(u->fd, FALLOC_FL_KEEP_SIZE, offset, length); + } while(ret < 0 && errno == EINTR); +#elif defined(F_PREALLOCATE) + /* Mac-specific */ + fstore_t fs = {}; + + fs.fst_flags = F_ALLOCATECONTIG; + fs.fst_posmode = F_VOLPOSMODE; + fs.fst_offset = offset; + fs.fst_length = length; + + ret = fcntl(u->fd, F_PREALLOCATE, &fs); + if(ret < 0) { + fs.fst_flags = F_ALLOCATEALL; + ret = fcntl(u->fd, F_PREALLOCATE, &fs); + } +#elif !defined(HAVE_POSIX_FALLOCATE) + u->common.posix_errno = ENOTSUP; + return 0; +#endif + +#ifdef HAVE_POSIX_FALLOCATE + if(ret < 0) { + do { + ret = posix_fallocate(u->fd, offset, length); + + /* On Linux and Solaris for example, posix_fallocate() returns a + * positive error number on error and it does not set errno. On + * FreeBSD however (9.0 at least), it returns -1 on error and it + * sets errno. */ + if (ret > 0) { + errno = ret; + ret = -1; + } + } while(ret < 0 && errno == EINTR); + } +#endif + + if(ret < 0) { + u->common.posix_errno = errno; + return 0; + } + + return 1; +} + +int efile_truncate(efile_data_t *d) { + efile_unix_t *u = (efile_unix_t*)d; + off_t offset; + + offset = lseek(u->fd, 0, SEEK_CUR); + + if(offset < 0) { + u->common.posix_errno = errno; + return 0; + } + + if(ftruncate(u->fd, offset) < 0) { + u->common.posix_errno = errno; + return 0; + } + + return 1; +} + +posix_errno_t efile_read_info(const efile_path_t *path, int follow_links, efile_fileinfo_t *result) { + struct stat data; + + if(follow_links) { + if(stat((const char*)path->data, &data) < 0) { + return errno; + } + } else { + if(lstat((const char*)path->data, &data) < 0) { + return errno; + } + } + + if(S_ISCHR(data.st_mode) || S_ISBLK(data.st_mode)) { + result->type = EFILE_FILETYPE_DEVICE; + } else if(S_ISDIR(data.st_mode)) { + result->type = EFILE_FILETYPE_DIRECTORY; + } else if(S_ISREG(data.st_mode)) { + result->type = EFILE_FILETYPE_REGULAR; + } else if(S_ISLNK(data.st_mode)) { + result->type = EFILE_FILETYPE_SYMLINK; + } else { + result->type = EFILE_FILETYPE_OTHER; + } + + result->a_time = (Sint64)data.st_atime; + result->m_time = (Sint64)data.st_mtime; + result->c_time = (Sint64)data.st_ctime; + result->size = data.st_size; + + result->major_device = data.st_dev; + result->minor_device = data.st_rdev; + result->links = data.st_nlink; + result->inode = data.st_ino; + result->mode = data.st_mode; + result->uid = data.st_uid; + result->gid = data.st_gid; + +#ifndef NO_ACCESS + result->access = EFILE_ACCESS_NONE; + + if(access((const char*)path->data, R_OK) == 0) { + result->access |= EFILE_ACCESS_READ; + } + if(access((const char*)path->data, W_OK) == 0) { + result->access |= EFILE_ACCESS_WRITE; + } +#else + /* Just look at read/write access for owner. */ + result->access = ((data.st_mode >> 6) & 07) >> 1; +#endif + + return 0; +} + +posix_errno_t efile_set_permissions(const efile_path_t *path, Uint32 permissions) { + const mode_t MUTABLE_MODES = (S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO); + mode_t new_modes = permissions & MUTABLE_MODES; + + if(chmod((const char*)path->data, new_modes) < 0) { + new_modes &= ~(S_ISUID | S_ISGID); + + if (chmod((const char*)path->data, new_modes) < 0) { + return errno; + } + } + + return 0; +} + +posix_errno_t efile_set_owner(const efile_path_t *path, Uint32 owner, Uint32 group) { + if(chown((const char*)path->data, owner, group) < 0) { + return errno; + } + + return 0; +} + +posix_errno_t efile_set_time(const efile_path_t *path, Sint64 a_time, Sint64 m_time, Sint64 c_time) { + struct utimbuf tval; + + tval.actime = (time_t)a_time; + tval.modtime = (time_t)m_time; + + (void)c_time; + + if(utime((const char*)path->data, &tval) < 0) { + return errno; + } + + return 0; +} + +posix_errno_t efile_read_link(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result) { + ErlNifBinary result_bin; + + if(!enif_alloc_binary(256, &result_bin)) { + return ENOMEM; + } + + for(;;) { + ssize_t bytes_copied; + + bytes_copied = readlink((const char*)path->data, (char*)result_bin.data, + result_bin.size); + + if(bytes_copied <= 0) { + posix_errno_t saved_errno = errno; + enif_release_binary(&result_bin); + return saved_errno; + } else if(bytes_copied < result_bin.size) { + if(!enif_realloc_binary(&result_bin, bytes_copied)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + + (*result) = enif_make_binary(env, &result_bin); + + return 0; + } + + /* The result didn't fit into the buffer, so we'll try again with a + * larger one. */ + + if(!enif_realloc_binary(&result_bin, result_bin.size * 2)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + } +} + +static int is_ignored_name(int name_length, const char *name) { + if(name_length == 1 && name[0] == '.') { + return 1; + } else if(name_length == 2 && memcmp(name, "..", 2) == 0) { + return 1; + } + + return 0; +} + +posix_errno_t efile_list_dir(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result) { + ERL_NIF_TERM list_head; + + struct dirent *dir_entry; + DIR *dir_stream; + + dir_stream = opendir((const char*)path->data); + if(dir_stream == NULL) { + posix_errno_t saved_errno = errno; + *result = enif_make_list(env, 0); + return saved_errno; + } + + list_head = enif_make_list(env, 0); + dir_entry = readdir(dir_stream); + + while(dir_entry != NULL) { + int name_length = strlen(dir_entry->d_name); + + if(!is_ignored_name(name_length, dir_entry->d_name)) { + unsigned char *name_bytes; + ERL_NIF_TERM name_term; + + name_bytes = enif_make_new_binary(env, name_length, &name_term); + sys_memcpy(name_bytes, dir_entry->d_name, name_length); + + list_head = enif_make_list_cell(env, name_term, list_head); + } + + dir_entry = readdir(dir_stream); + } + + (*result) = list_head; + closedir(dir_stream); + + return 0; +} + +posix_errno_t efile_rename(const efile_path_t *old_path, const efile_path_t *new_path) { + if(rename((const char*)old_path->data, (const char*)new_path->data) < 0) { + if(errno == ENOTEMPTY) { + return EEXIST; + } + + if(strcmp((const char*)old_path->data, "/") == 0) { + /* Alpha reports renaming / as EBUSY and Linux reports it as EACCES + * instead of EINVAL.*/ + return EINVAL; + } + + return errno; + } + + return 0; +} + +posix_errno_t efile_make_hard_link(const efile_path_t *existing_path, const efile_path_t *new_path) { + if(link((const char*)existing_path->data, (const char*)new_path->data) < 0) { + return errno; + } + + return 0; +} + +posix_errno_t efile_make_soft_link(const efile_path_t *existing_path, const efile_path_t *new_path) { + if(symlink((const char*)existing_path->data, (const char*)new_path->data) < 0) { + return errno; + } + + return 0; +} + +posix_errno_t efile_make_dir(const efile_path_t *path) { +#ifdef NO_MKDIR_MODE + if(mkdir((const char*)path->data) < 0) { +#else + if(mkdir((const char*)path->data, DIR_MODE) < 0) { +#endif + return errno; + } + + return 0; +} + +posix_errno_t efile_del_file(const efile_path_t *path) { + if(unlink((const char*)path->data) < 0) { + /* Linux sets the wrong error code. */ + if(errno == EISDIR) { + return EPERM; + } + + return errno; + } + + return 0; +} + +posix_errno_t efile_del_dir(const efile_path_t *path) { + if(rmdir((const char*)path->data) < 0) { + posix_errno_t saved_errno = errno; + + if(saved_errno == ENOTEMPTY) { + saved_errno = EEXIST; + } + + /* The error code might be wrong if we're trying to delete the current + * directory. */ + if(saved_errno == EEXIST) { + struct stat path_stat, cwd_stat; + int has_stat; + + has_stat = (stat((const char*)path->data, &path_stat) == 0); + has_stat &= (stat(".", &cwd_stat) == 0); + + if(has_stat && path_stat.st_ino == cwd_stat.st_ino) { + if(path_stat.st_dev == cwd_stat.st_dev) { + return EINVAL; + } + } + } + + return saved_errno; + } + + return 0; +} + +posix_errno_t efile_set_cwd(const efile_path_t *path) { + if(chdir((const char*)path->data) < 0) { + return errno; + } + + return 0; +} + +posix_errno_t efile_get_device_cwd(ErlNifEnv *env, int device_index, ERL_NIF_TERM *result) { + (void)device_index; + (void)result; + (void)env; + + return ENOTSUP; +} + +posix_errno_t efile_get_cwd(ErlNifEnv *env, ERL_NIF_TERM *result) { + ErlNifBinary result_bin; + size_t bytes_copied; + + if(!enif_alloc_binary(256, &result_bin)) { + return ENOMEM; + } + + while(getcwd((char*)result_bin.data, result_bin.size) == NULL) { + posix_errno_t saved_errno = errno; + + if(saved_errno != ERANGE) { + enif_release_binary(&result_bin); + return saved_errno; + } else { + if(!enif_realloc_binary(&result_bin, result_bin.size * 2)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + } + } + + /* getcwd(2) guarantees null-termination. */ + bytes_copied = strlen((const char*)result_bin.data); + + if(!enif_realloc_binary(&result_bin, bytes_copied)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + + (*result) = enif_make_binary(env, &result_bin); + + return 0; +} + +posix_errno_t efile_altname(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result) { + (void)path; + (void)result; + + return ENOTSUP; +} diff --git a/erts/emulator/nifs/win32/win_prim_file.c b/erts/emulator/nifs/win32/win_prim_file.c new file mode 100644 index 0000000000..9f993f1d24 --- /dev/null +++ b/erts/emulator/nifs/win32/win_prim_file.c @@ -0,0 +1,1427 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson 2017. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +#include "erl_nif.h" +#include "config.h" +#include "sys.h" + +#include "prim_file_nif.h" + +#include <windows.h> +#include <strsafe.h> +#include <wchar.h> + +#define IS_SLASH(a) ((a) == L'\\' || (a) == L'/') + +#define FILE_SHARE_FLAGS (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE) + +#define LP_PREFIX L"\\\\?\\" +#define LP_PREFIX_SIZE (sizeof(LP_PREFIX) - sizeof(WCHAR)) +#define LP_PREFIX_LENGTH (LP_PREFIX_SIZE / sizeof(WCHAR)) + +#define PATH_LENGTH(path) (path->size / sizeof(WCHAR) - 1) + +#define ASSERT_PATH_FORMAT(path) \ + do { \ + ASSERT(PATH_LENGTH(path) >= 4 && \ + !memcmp(path->data, LP_PREFIX, LP_PREFIX_SIZE)); \ + ASSERT(PATH_LENGTH(path) == wcslen((WCHAR*)path->data)); \ + } while(0) + +#define TICKS_PER_SECOND (10000000ULL) +#define EPOCH_DIFFERENCE (11644473600LL) + +#define FILETIME_TO_EPOCH(epoch, ft) \ + do { \ + ULARGE_INTEGER ull; \ + ull.LowPart = (ft).dwLowDateTime; \ + ull.HighPart = (ft).dwHighDateTime; \ + (epoch) = ((ull.QuadPart / TICKS_PER_SECOND) - EPOCH_DIFFERENCE); \ + } while(0) + +#define EPOCH_TO_FILETIME(ft, epoch) \ + do { \ + ULARGE_INTEGER ull; \ + ull.QuadPart = (((epoch) + EPOCH_DIFFERENCE) * TICKS_PER_SECOND); \ + (ft).dwLowDateTime = ull.LowPart; \ + (ft).dwHighDateTime = ull.HighPart; \ + } while(0) + +typedef struct { + efile_data_t common; + HANDLE handle; +} efile_win_t; + +static int windows_to_posix_errno(DWORD last_error); + +static int has_invalid_null_termination(const ErlNifBinary *path) { + const WCHAR *null_pos, *end_pos; + + null_pos = wmemchr((const WCHAR*)path->data, L'\0', path->size); + end_pos = (const WCHAR*)&path->data[path->size] - 1; + + if(null_pos == NULL) { + return 1; + } + + /* prim_file:internal_name2native sometimes feeds us data that is "doubly" + * NUL-terminated, so we'll accept any number of trailing NULs so long as + * they aren't interrupted by anything else. */ + while(null_pos < end_pos && (*null_pos) == L'\0') { + null_pos++; + } + + return null_pos != end_pos; +} + +static posix_errno_t get_full_path(ErlNifEnv *env, WCHAR *input, efile_path_t *result) { + DWORD maximum_length, actual_length; + int add_long_prefix; + + maximum_length = GetFullPathNameW(input, 0, NULL, NULL); + add_long_prefix = 0; + + if(maximum_length == 0) { + /* POSIX doesn't have the concept of a "path error" in the same way + * Windows does, so we'll return ENOENT since that's what most POSIX + * APIs would return if they were fed such garbage. */ + return ENOENT; + } + + maximum_length += LP_PREFIX_LENGTH; + + if(!enif_alloc_binary(maximum_length * sizeof(WCHAR), result)) { + return ENOMEM; + } + + actual_length = GetFullPathNameW(input, maximum_length, (WCHAR*)result->data, NULL); + + if(actual_length < maximum_length) { + int has_long_path_prefix; + WCHAR *path_start; + + /* Make sure we have a long-path prefix; GetFullPathNameW only adds one + * if the path is relative. */ + has_long_path_prefix = actual_length >= LP_PREFIX_LENGTH && + !sys_memcmp(result->data, LP_PREFIX, LP_PREFIX_SIZE); + + if(!has_long_path_prefix) { + sys_memmove(result->data + LP_PREFIX_SIZE, result->data, + (actual_length + 1) * sizeof(WCHAR)); + sys_memcpy(result->data, LP_PREFIX, LP_PREFIX_SIZE); + actual_length += LP_PREFIX_LENGTH; + } + + path_start = (WCHAR*)result->data; + + /* We're removing trailing slashes since quite a few APIs refuse to + * work with them, and none require them. We only check the last + * character since GetFullPathNameW folds slashes together. */ + if(IS_SLASH(path_start[actual_length - 1])) { + if(path_start[actual_length - 2] != L':') { + path_start[actual_length - 1] = L'\0'; + actual_length--; + } + } + + if(!enif_realloc_binary(result, (actual_length + 1) * sizeof(WCHAR))) { + enif_release_binary(result); + return ENOMEM; + } + + enif_make_binary(env, result); + return 0; + } + + /* We may end up here if the current directory changes to something longer + * between/during GetFullPathName. There's nothing sensible we can do about + * this. */ + + enif_release_binary(result); + + return EINVAL; +} + +posix_errno_t efile_marshal_path(ErlNifEnv *env, ERL_NIF_TERM path, efile_path_t *result) { + ErlNifBinary raw_path; + + if(!enif_inspect_binary(env, path, &raw_path)) { + return EINVAL; + } else if(raw_path.size % sizeof(WCHAR)) { + return EINVAL; + } + + if(has_invalid_null_termination(&raw_path)) { + return EINVAL; + } + + return get_full_path(env, (WCHAR*)raw_path.data, result); +} + +ERL_NIF_TERM efile_get_handle(ErlNifEnv *env, efile_data_t *d) { + efile_win_t *w = (efile_win_t*)d; + + ERL_NIF_TERM result; + unsigned char *bits; + + bits = enif_make_new_binary(env, sizeof(w->handle), &result); + memcpy(bits, &w->handle, sizeof(w->handle)); + + return result; +} + +/** @brief Converts a native path to the preferred form in "erlang space," + * without path-prefixes, forward-slashes, or NUL terminators. */ +static int normalize_path_result(ErlNifBinary *path) { + WCHAR *path_iterator, *path_start, *path_end; + int length; + + path_start = (WCHAR*)path->data; + length = wcslen(path_start); + + ASSERT(length < path->size / sizeof(WCHAR)); + + /* Get rid of the long-path prefix, if present. */ + if(length >= LP_PREFIX_LENGTH) { + if(!sys_memcmp(path_start, LP_PREFIX, LP_PREFIX_SIZE)) { + length -= LP_PREFIX_LENGTH; + + sys_memmove(path_start, &path_start[LP_PREFIX_LENGTH], + length * sizeof(WCHAR)); + } + } + + path_end = &path_start[length]; + path_iterator = path_start; + + /* Convert drive letters to lowercase, if present. */ + if(length >= 2 && path_start[1] == L':') { + WCHAR drive_letter = path_start[0]; + + if(drive_letter >= L'A' && drive_letter <= L'Z') { + path_start[0] = drive_letter - L'A' + L'a'; + } + } + + while(path_iterator < path_end) { + if(*path_iterator == L'\\') { + *path_iterator = L'/'; + } + + path_iterator++; + } + + /* Truncate the result to its actual length; we don't want to include the + * NUL terminator. */ + return enif_realloc_binary(path, length * sizeof(WCHAR)); +} + +/* @brief Checks whether all the given attributes are set on the object at the + * given path. Note that it assumes false on errors. */ +static int has_file_attributes(const efile_path_t *path, DWORD mask) { + DWORD attributes = GetFileAttributesW((WCHAR*)path->data); + + if(attributes == INVALID_FILE_ATTRIBUTES) { + return 0; + } + + return !!((attributes & mask) == mask); +} + +static int is_ignored_name(int name_length, const WCHAR *name) { + if(name_length == 1 && name[0] == L'.') { + return 1; + } else if(name_length == 2 && !sys_memcmp(name, L"..", 2 * sizeof(WCHAR))) { + return 1; + } + + return 0; +} + +static int get_drive_number(const efile_path_t *path) { + const WCHAR *path_start; + int length; + + ASSERT_PATH_FORMAT(path); + + path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; + length = PATH_LENGTH(path) - LP_PREFIX_LENGTH; + + if(length >= 2 && path_start[1] == L':') { + WCHAR drive_letter = path_start[0]; + + if(drive_letter >= L'A' && drive_letter <= L'Z') { + return drive_letter - L'A' + 1; + } else if(drive_letter >= L'a' && drive_letter <= L'z') { + return drive_letter - L'a' + 1; + } + } + + return -1; +} + +/* @brief Checks whether two *paths* are on the same mount point; they don't + * have to refer to existing or accessible files/directories. */ +static int has_same_mount_point(const efile_path_t *path_a, const efile_path_t *path_b) { + WCHAR *mount_a, *mount_b; + int result = 0; + + mount_a = enif_alloc(path_a->size); + mount_b = enif_alloc(path_b->size); + + if(mount_a != NULL && mount_b != NULL) { + int length_a, length_b; + + length_a = PATH_LENGTH(path_a); + length_b = PATH_LENGTH(path_b); + + if(GetVolumePathNameW((WCHAR*)path_a->data, mount_a, length_a)) { + ASSERT(wcslen(mount_a) <= length_a); + + if(GetVolumePathNameW((WCHAR*)path_b->data, mount_b, length_b)) { + ASSERT(wcslen(mount_b) <= length_b); + + result = !_wcsicmp(mount_a, mount_b); + } + } + } + + if(mount_b != NULL) { + enif_free(mount_b); + } + + if(mount_a != NULL) { + enif_free(mount_a); + } + + return result; +} + +/* Mirrors the PathIsRootW function of the shell API, but doesn't choke on + * paths longer than MAX_PATH. */ +static int is_path_root(const efile_path_t *path) { + const WCHAR *path_start, *path_end; + int length; + + ASSERT_PATH_FORMAT(path); + + path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; + length = PATH_LENGTH(path) - LP_PREFIX_LENGTH; + + path_end = &path_start[length]; + + if(length == 1) { + /* A single \ refers to the root of the current working directory. */ + return IS_SLASH(path_start[0]); + } else if(length == 3 && iswalpha(path_start[0]) && path_start[1] == L':') { + /* Drive letter. */ + return IS_SLASH(path_start[2]); + } else if(length >= 4) { + /* Check whether we're a UNC root, eg. \\server, \\server\share */ + const WCHAR *path_iterator; + + if(!IS_SLASH(path_start[0]) || !IS_SLASH(path_start[1])) { + return 0; + } + + path_iterator = path_start + 2; + + /* Slide to the slash between the server and share names, if present. */ + while(path_iterator < path_end && !IS_SLASH(*path_iterator)) { + path_iterator++; + } + + /* Slide past the end of the string, stopping at the first slash we + * encounter. */ + do { + path_iterator++; + } while(path_iterator < path_end && !IS_SLASH(*path_iterator)); + + /* If we're past the end of the string and it didnt't end with a slash, + * then we're a root path. */ + return path_iterator >= path_end && !IS_SLASH(path_start[length - 1]); + } + + return 0; +} + +posix_errno_t efile_open(const efile_path_t *path, enum efile_modes_t modes, + ErlNifResourceType *nif_type, efile_data_t **d) { + + DWORD attributes, access_flags, open_mode; + HANDLE handle; + + ASSERT_PATH_FORMAT(path); + + access_flags = 0; + open_mode = 0; + + if(modes & EFILE_MODE_READ && !(modes & EFILE_MODE_WRITE)) { + access_flags = GENERIC_READ; + open_mode = OPEN_EXISTING; + } else if(modes & EFILE_MODE_WRITE && !(modes & EFILE_MODE_READ)) { + access_flags = GENERIC_WRITE; + open_mode = CREATE_ALWAYS; + } else if(modes & EFILE_MODE_READ_WRITE) { + access_flags = GENERIC_READ | GENERIC_WRITE; + open_mode = OPEN_ALWAYS; + } else { + return EINVAL; + } + + if(modes & EFILE_MODE_APPEND) { + access_flags |= FILE_APPEND_DATA; + open_mode = OPEN_ALWAYS; + } + + if(modes & EFILE_MODE_EXCLUSIVE) { + open_mode = CREATE_NEW; + } + + if(modes & EFILE_MODE_SYNC) { + attributes = FILE_FLAG_WRITE_THROUGH; + } else { + attributes = FILE_ATTRIBUTE_NORMAL; + } + + handle = CreateFileW((WCHAR*)path->data, access_flags, + FILE_SHARE_FLAGS, NULL, open_mode, attributes, NULL); + + if(handle != INVALID_HANDLE_VALUE) { + efile_win_t *w; + + w = (efile_win_t*)enif_alloc_resource(nif_type, sizeof(efile_win_t)); + w->handle = handle; + + EFILE_INIT_RESOURCE(&w->common, modes); + (*d) = &w->common; + + return 0; + } else { + DWORD last_error = GetLastError(); + + /* Rewrite all failures on directories to EISDIR to match the old + * driver. */ + if(has_file_attributes(path, FILE_ATTRIBUTE_DIRECTORY)) { + return EISDIR; + } + + return windows_to_posix_errno(last_error); + } +} + +int efile_close(efile_data_t *d) { + efile_win_t *w = (efile_win_t*)d; + HANDLE handle; + + ASSERT(erts_atomic32_read_nob(&d->state) == EFILE_STATE_CLOSED); + ASSERT(w->handle != INVALID_HANDLE_VALUE); + + handle = w->handle; + w->handle = INVALID_HANDLE_VALUE; + + if(!CloseHandle(handle)) { + w->common.posix_errno = windows_to_posix_errno(GetLastError()); + return 0; + } + + return 1; +} + +static void shift_overlapped(OVERLAPPED *overlapped, DWORD shift) { + LARGE_INTEGER offset; + + ASSERT(shift >= 0); + + offset.HighPart = overlapped->OffsetHigh; + offset.LowPart = overlapped->Offset; + + /* ~(Uint64)0 is a magic value ("append to end of file") which needs to be + * preserved. Other positions resulting in overflow would have errored out + * just prior to this point. */ + if(offset.QuadPart != ERTS_UINT64_MAX) { + offset.QuadPart += shift; + } + + /* All unused fields must be zeroed for the next call. */ + sys_memset(overlapped, 0, sizeof(*overlapped)); + overlapped->OffsetHigh = offset.HighPart; + overlapped->Offset = offset.LowPart; +} + +static void shift_iov(SysIOVec **iov, int *iovlen, DWORD shift) { + SysIOVec *head_vec = (*iov); + + ASSERT(shift >= 0); + + while(shift > 0) { + ASSERT(head_vec < &(*iov)[*iovlen]); + + if(shift < head_vec->iov_len) { + head_vec->iov_base = (char*)head_vec->iov_base + shift; + head_vec->iov_len -= shift; + break; + } else { + shift -= head_vec->iov_len; + head_vec++; + } + } + + (*iovlen) -= head_vec - (*iov); + (*iov) = head_vec; +} + +typedef BOOL (WINAPI *io_op_t)(HANDLE, LPVOID, DWORD, LPDWORD, LPOVERLAPPED); + +static Sint64 internal_sync_io(efile_win_t *w, io_op_t operation, + SysIOVec *iov, int iovlen, OVERLAPPED *overlapped) { + + Sint64 bytes_processed = 0; + + for(;;) { + DWORD block_bytes_processed, last_error; + BOOL succeeded; + + if(iovlen < 1) { + return bytes_processed; + } + + succeeded = operation(w->handle, iov->iov_base, iov->iov_len, + &block_bytes_processed, overlapped); + last_error = GetLastError(); + + if(!succeeded && (last_error != ERROR_HANDLE_EOF)) { + w->common.posix_errno = windows_to_posix_errno(last_error); + return -1; + } else if(block_bytes_processed == 0) { + /* EOF */ + return bytes_processed; + } + + if(overlapped != NULL) { + shift_overlapped(overlapped, block_bytes_processed); + } + + shift_iov(&iov, &iovlen, block_bytes_processed); + + bytes_processed += block_bytes_processed; + } +} + +Sint64 efile_readv(efile_data_t *d, SysIOVec *iov, int iovlen) { + efile_win_t *w = (efile_win_t*)d; + + return internal_sync_io(w, ReadFile, iov, iovlen, NULL); +} + +Sint64 efile_writev(efile_data_t *d, SysIOVec *iov, int iovlen) { + efile_win_t *w = (efile_win_t*)d; + + OVERLAPPED __overlapped, *overlapped; + Uint64 bytes_written; + + if(w->common.modes & EFILE_MODE_APPEND) { + overlapped = &__overlapped; + + sys_memset(overlapped, 0, sizeof(*overlapped)); + overlapped->OffsetHigh = 0xFFFFFFFF; + overlapped->Offset = 0xFFFFFFFF; + } else { + overlapped = NULL; + } + + return internal_sync_io(w, WriteFile, iov, iovlen, overlapped); +} + +Sint64 efile_preadv(efile_data_t *d, Sint64 offset, SysIOVec *iov, int iovlen) { + efile_win_t *w = (efile_win_t*)d; + + OVERLAPPED overlapped; + + sys_memset(&overlapped, 0, sizeof(overlapped)); + overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF; + overlapped.Offset = offset & 0xFFFFFFFF; + + return internal_sync_io(w, ReadFile, iov, iovlen, &overlapped); +} + +Sint64 efile_pwritev(efile_data_t *d, Sint64 offset, SysIOVec *iov, int iovlen) { + efile_win_t *w = (efile_win_t*)d; + + OVERLAPPED overlapped; + + sys_memset(&overlapped, 0, sizeof(overlapped)); + overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF; + overlapped.Offset = offset & 0xFFFFFFFF; + + return internal_sync_io(w, WriteFile, iov, iovlen, &overlapped); +} + +int efile_seek(efile_data_t *d, enum efile_seek_t seek, Sint64 offset, Sint64 *new_position) { + efile_win_t *w = (efile_win_t*)d; + + LARGE_INTEGER large_offset, large_new_position; + DWORD whence; + + switch(seek) { + case EFILE_SEEK_BOF: whence = FILE_BEGIN; break; + case EFILE_SEEK_CUR: whence = FILE_CURRENT; break; + case EFILE_SEEK_EOF: whence = FILE_END; break; + default: ERTS_INTERNAL_ERROR("Invalid seek parameter"); + } + + large_offset.QuadPart = offset; + + if(!SetFilePointerEx(w->handle, large_offset, &large_new_position, whence)) { + w->common.posix_errno = windows_to_posix_errno(GetLastError()); + return 0; + } + + (*new_position) = large_new_position.QuadPart; + + return 1; +} + +int efile_sync(efile_data_t *d, int data_only) { + efile_win_t *w = (efile_win_t*)d; + + /* Windows doesn't support data-only syncing. */ + (void)data_only; + + if(!FlushFileBuffers(w->handle)) { + w->common.posix_errno = windows_to_posix_errno(GetLastError()); + return 0; + } + + return 1; +} + +int efile_advise(efile_data_t *d, Sint64 offset, Sint64 length, enum efile_advise_t advise) { + /* Windows doesn't support this, but we'll pretend it does since the call + * is only a recommendation even on systems that do support it. */ + + (void)d; + (void)offset; + (void)length; + (void)advise; + + return 1; +} + +int efile_allocate(efile_data_t *d, Sint64 offset, Sint64 length) { + efile_win_t *w = (efile_win_t*)d; + + (void)d; + (void)offset; + (void)length; + + w->common.posix_errno = ENOTSUP; + + return 0; +} + +int efile_truncate(efile_data_t *d) { + efile_win_t *w = (efile_win_t*)d; + + if(!SetEndOfFile(w->handle)) { + w->common.posix_errno = windows_to_posix_errno(GetLastError()); + return 0; + } + + return 1; +} + +static int is_executable_file(const efile_path_t *path) { + /* We're using the file extension in order to be quirks-compliant with the + * old driver, which never bothered to check the actual permissions. We + * could easily do so now (cf. GetNamedSecurityInfo) but the execute + * permission is only relevant for files that are started with the default + * loader, and batch files run just fine with read permission alone. */ + + int length = PATH_LENGTH(path); + + if(length >= 4) { + const WCHAR *last_four = &((WCHAR*)path->data)[length - 4]; + + if (!_wcsicmp(last_four, L".exe") || + !_wcsicmp(last_four, L".cmd") || + !_wcsicmp(last_four, L".bat") || + !_wcsicmp(last_four, L".com")) { + return 1; + } + } + + return 0; +} + +posix_errno_t efile_read_info(const efile_path_t *path, int follow_links, efile_fileinfo_t *result) { + BY_HANDLE_FILE_INFORMATION native_file_info; + DWORD attributes; + + sys_memset(&native_file_info, 0, sizeof(native_file_info)); + + attributes = GetFileAttributesW((WCHAR*)path->data); + + if(attributes == INVALID_FILE_ATTRIBUTES) { + DWORD last_error = GetLastError(); + + /* Querying a network share root fails with ERROR_BAD_NETPATH, so we'll + * fake it as a directory just like local roots. */ + if(!is_path_root(path) || last_error != ERROR_BAD_NETPATH) { + return windows_to_posix_errno(last_error); + } + + attributes = FILE_ATTRIBUTE_DIRECTORY; + } else if(is_path_root(path)) { + /* Local (or mounted) roots can be queried with GetFileAttributesW but + * lack support for GetFileInformationByHandle, so we'll skip that + * part. */ + } else { + HANDLE handle; + + if(follow_links && (attributes & FILE_ATTRIBUTE_REPARSE_POINT)) { + posix_errno_t posix_errno; + efile_path_t resolved_path; + + posix_errno = internal_read_link(path, &resolved_path); + + if(posix_errno != 0) { + return posix_errno; + } + + return efile_read_info(&resolved_path, 0, result); + } + + handle = CreateFileW((const WCHAR*)path->data, GENERIC_READ, + FILE_SHARE_FLAGS, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, + NULL); + + /* The old driver never cared whether this succeeded. */ + if(handle != INVALID_HANDLE_VALUE) { + GetFileInformationByHandle(handle, &native_file_info); + CloseHandle(handle); + } + + FILETIME_TO_EPOCH(result->m_time, native_file_info.ftLastWriteTime); + FILETIME_TO_EPOCH(result->a_time, native_file_info.ftLastAccessTime); + FILETIME_TO_EPOCH(result->c_time, native_file_info.ftCreationTime); + + if(result->m_time == -EPOCH_DIFFERENCE) { + /* Default to 1970 just like the old driver. */ + result->m_time = 0; + } + + if(result->a_time == -EPOCH_DIFFERENCE) { + result->a_time = result->m_time; + } + + if(result->c_time == -EPOCH_DIFFERENCE) { + result->c_time = result->m_time; + } + } + + if(attributes & FILE_ATTRIBUTE_REPARSE_POINT) { + result->type = EFILE_FILETYPE_SYMLINK; + /* This should be _S_IFLNK, but the old driver always set + * non-directories to _S_IFREG. */ + result->mode |= _S_IFREG; + } else if(attributes & FILE_ATTRIBUTE_DIRECTORY) { + result->type = EFILE_FILETYPE_DIRECTORY; + result->mode |= _S_IFDIR | _S_IEXEC; + } else { + if(is_executable_file(path)) { + result->mode |= _S_IEXEC; + } + + result->type = EFILE_FILETYPE_REGULAR; + result->mode |= _S_IFREG; + } + + if(!(attributes & FILE_ATTRIBUTE_READONLY)) { + result->access = EFILE_ACCESS_READ | EFILE_ACCESS_WRITE; + result->mode |= _S_IREAD | _S_IWRITE; + } else { + result->access = EFILE_ACCESS_READ; + result->mode |= _S_IREAD; + } + + /* Propagate user mode-bits to group/other fields */ + result->mode |= (result->mode & 0700) >> 3; + result->mode |= (result->mode & 0700) >> 6; + + result->size = + ((Uint64)native_file_info.nFileSizeHigh << 32ull) | + (Uint64)native_file_info.nFileSizeLow; + + result->links = MAX(1, native_file_info.nNumberOfLinks); + + result->major_device = get_drive_number(path); + result->minor_device = 0; + result->inode = 0; + result->uid = 0; + result->gid = 0; + + return 0; +} + +posix_errno_t efile_set_permissions(const efile_path_t *path, Uint32 permissions) { + DWORD attributes = GetFileAttributesW((WCHAR*)path->data); + + if(attributes == INVALID_FILE_ATTRIBUTES) { + return windows_to_posix_errno(GetLastError()); + } + + if(permissions & _S_IWRITE) { + attributes &= ~FILE_ATTRIBUTE_READONLY; + } else { + attributes |= FILE_ATTRIBUTE_READONLY; + } + + if(SetFileAttributesW((WCHAR*)path->data, attributes)) { + return 0; + } + + return windows_to_posix_errno(GetLastError()); +} + +posix_errno_t efile_set_owner(const efile_path_t *path, Uint32 owner, Uint32 group) { + (void)path; + (void)owner; + (void)group; + + return 0; +} + +posix_errno_t efile_set_time(const efile_path_t *path, Sint64 a_time, Sint64 m_time, Sint64 c_time) { + FILETIME accessed, modified, created; + DWORD last_error, attributes; + HANDLE handle; + + attributes = GetFileAttributesW((WCHAR*)path->data); + + if(attributes == INVALID_FILE_ATTRIBUTES) { + return windows_to_posix_errno(GetLastError()); + } + + /* If the file is read-only, we have to make it temporarily writable while + * setting new metadata. */ + if(attributes & FILE_ATTRIBUTE_READONLY) { + DWORD without_readonly = attributes & ~FILE_ATTRIBUTE_READONLY; + + if(!SetFileAttributesW((WCHAR*)path->data, without_readonly)) { + return windows_to_posix_errno(GetLastError()); + } + } + + EPOCH_TO_FILETIME(modified, m_time); + EPOCH_TO_FILETIME(accessed, a_time); + EPOCH_TO_FILETIME(created, c_time); + + handle = CreateFileW((WCHAR*)path->data, GENERIC_READ | GENERIC_WRITE, + FILE_SHARE_FLAGS, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + last_error = GetLastError(); + + if(handle != INVALID_HANDLE_VALUE) { + if(SetFileTime(handle, &created, &accessed, &modified)) { + last_error = ERROR_SUCCESS; + } else { + last_error = GetLastError(); + } + + CloseHandle(handle); + } + + if(attributes & FILE_ATTRIBUTE_READONLY) { + SetFileAttributesW((WCHAR*)path->data, attributes); + } + + return windows_to_posix_errno(last_error); +} + +static posix_errno_t internal_read_link(const efile_path_t *path, efile_path_t *result) { + DWORD required_length, actual_length; + HANDLE link_handle; + DWORD last_error; + + link_handle = CreateFileW((WCHAR*)path->data, GENERIC_READ, + FILE_SHARE_FLAGS, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + last_error = GetLastError(); + + if(link_handle == INVALID_HANDLE_VALUE) { + return windows_to_posix_errno(last_error); + } + + required_length = GetFinalPathNameByHandleW(link_handle, NULL, 0, 0); + last_error = GetLastError(); + + if(required_length <= 0) { + CloseHandle(link_handle); + return windows_to_posix_errno(last_error); + } + + /* Unlike many other path functions (eg. GetFullPathNameW), this one + * includes the NUL terminator in its required length. */ + if(!enif_alloc_binary(required_length * sizeof(WCHAR), result)) { + CloseHandle(link_handle); + return ENOMEM; + } + + actual_length = GetFinalPathNameByHandleW(link_handle, + (WCHAR*)result->data, required_length, 0); + last_error = GetLastError(); + + CloseHandle(link_handle); + + if(actual_length == 0 || actual_length >= required_length) { + enif_release_binary(result); + return windows_to_posix_errno(last_error); + } + + /* GetFinalPathNameByHandle always prepends with "\\?\" and NUL-terminates, + * so we never have to touch-up the resulting path. */ + + ASSERT_PATH_FORMAT(result); + + return 0; +} + +posix_errno_t efile_read_link(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result) { + posix_errno_t posix_errno; + ErlNifBinary result_bin; + DWORD attributes; + + ASSERT_PATH_FORMAT(path); + + attributes = GetFileAttributesW((WCHAR*)path->data); + + if(attributes == INVALID_FILE_ATTRIBUTES) { + return windows_to_posix_errno(GetLastError()); + } else if(!(attributes & FILE_ATTRIBUTE_REPARSE_POINT)) { + return EINVAL; + } + + posix_errno = internal_read_link(path, &result_bin); + + if(posix_errno == 0) { + if(!normalize_path_result(&result_bin)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + + (*result) = enif_make_binary(env, &result_bin); + } + + return posix_errno; +} + +posix_errno_t efile_list_dir(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result) { + ERL_NIF_TERM list_head; + WIN32_FIND_DATAW data; + HANDLE search_handle; + WCHAR *search_path; + DWORD last_error; + + ASSERT_PATH_FORMAT(path); + + search_path = enif_alloc(path->size + 2 * sizeof(WCHAR)); + + if(search_path == NULL) { + return ENOMEM; + } + + sys_memcpy(search_path, path->data, path->size); + search_path[PATH_LENGTH(path) + 0] = L'\\'; + search_path[PATH_LENGTH(path) + 1] = L'*'; + search_path[PATH_LENGTH(path) + 2] = L'\0'; + + search_handle = FindFirstFileW(search_path, &data); + last_error = GetLastError(); + + enif_free(search_path); + + if(search_handle == INVALID_HANDLE_VALUE) { + return windows_to_posix_errno(last_error); + } + + list_head = enif_make_list(env, 0); + + do { + int name_length = wcslen(data.cFileName); + + if(!is_ignored_name(name_length, data.cFileName)) { + unsigned char *name_bytes; + ERL_NIF_TERM name_term; + size_t name_size; + + name_size = name_length * sizeof(WCHAR); + + name_bytes = enif_make_new_binary(env, name_size, &name_term); + sys_memcpy(name_bytes, data.cFileName, name_size); + + list_head = enif_make_list_cell(env, name_term, list_head); + } + } while(FindNextFileW(search_handle, &data)); + + FindClose(search_handle); + (*result) = list_head; + + return 0; +} + +posix_errno_t efile_rename(const efile_path_t *old_path, const efile_path_t *new_path) { + BOOL old_is_directory, new_is_directory; + DWORD move_flags, last_error; + + ASSERT_PATH_FORMAT(old_path); + ASSERT_PATH_FORMAT(new_path); + + move_flags = MOVEFILE_COPY_ALLOWED | MOVEFILE_WRITE_THROUGH; + + if(MoveFileExW((WCHAR*)old_path->data, (WCHAR*)new_path->data, move_flags)) { + return 0; + } + + last_error = GetLastError(); + + old_is_directory = has_file_attributes(old_path, FILE_ATTRIBUTE_DIRECTORY); + new_is_directory = has_file_attributes(new_path, FILE_ATTRIBUTE_DIRECTORY); + + switch(last_error) { + case ERROR_SHARING_VIOLATION: + case ERROR_ACCESS_DENIED: + if(old_is_directory) { + BOOL moved_into_itself; + + moved_into_itself = (old_path->size <= new_path->size) && + !_wcsnicmp((WCHAR*)old_path->data, (WCHAR*)new_path->data, + PATH_LENGTH(old_path)); + + if(moved_into_itself) { + return EINVAL; + } else if(is_path_root(old_path)) { + return EINVAL; + } + + /* Renaming a directory across volumes needs to be rewritten as + * EXDEV so that the caller can respond by simulating it with + * copy/delete operations. + * + * Files are handled through MOVEFILE_COPY_ALLOWED. */ + if(!has_same_mount_point(old_path, new_path)) { + return EXDEV; + } + } + break; + case ERROR_PATH_NOT_FOUND: + case ERROR_FILE_NOT_FOUND: + return ENOENT; + case ERROR_ALREADY_EXISTS: + case ERROR_FILE_EXISTS: + if(old_is_directory && !new_is_directory) { + return ENOTDIR; + } else if(!old_is_directory && new_is_directory) { + return EISDIR; + } else if(old_is_directory && new_is_directory) { + /* This will fail if the destination isn't empty. */ + if(RemoveDirectoryW((WCHAR*)new_path->data)) { + return efile_rename(old_path, new_path); + } + + return EEXIST; + } else if(!old_is_directory && !new_is_directory) { + /* This is pretty iffy; the public documentation says that the + * operation may EACCES on some systems when either file is open, + * which gives us room to use MOVEFILE_REPLACE_EXISTING and be done + * with it, but the old implementation simulated Unix semantics and + * there's a lot of code that relies on that. + * + * The simulation renames the destination to a scratch name to get + * around the fact that it's impossible to open (and by extension + * rename) a file that's been deleted while open. It has a few + * drawbacks though; + * + * 1) It's not atomic as there's a small window where there's no + * file at all on the destination path. + * 2) It will confuse applications that subscribe to folder + * changes. + * 3) It will fail if we lack general permission to write in the + * same folder. */ + + WCHAR *swap_path = enif_alloc(new_path->size + sizeof(WCHAR) * 64); + + if(swap_path == NULL) { + return ENOMEM; + } else { + static LONGLONG unique_counter = 0; + WCHAR *swap_path_end; + + /* We swap in the same folder as the destination to be + * reasonably sure that it's on the same volume. Note that + * we're avoiding GetTempFileNameW as it will fail on long + * paths. */ + + sys_memcpy(swap_path, (WCHAR*)new_path->data, new_path->size); + swap_path_end = swap_path + PATH_LENGTH(new_path); + + while(!IS_SLASH(*swap_path_end)) { + ASSERT(swap_path_end > swap_path); + swap_path_end--; + } + + StringCchPrintfW(&swap_path_end[1], 64, L"erl-%lx-%llx.tmp", + GetCurrentProcessId(), unique_counter); + InterlockedIncrement64(&unique_counter); + } + + if(MoveFileExW((WCHAR*)new_path->data, swap_path, MOVEFILE_REPLACE_EXISTING)) { + if(MoveFileExW((WCHAR*)old_path->data, (WCHAR*)new_path->data, move_flags)) { + last_error = ERROR_SUCCESS; + DeleteFileW(swap_path); + } else { + last_error = GetLastError(); + MoveFileW(swap_path, (WCHAR*)new_path->data); + } + } else { + last_error = GetLastError(); + DeleteFileW(swap_path); + } + + enif_free(swap_path); + + return windows_to_posix_errno(last_error); + } + + return EEXIST; + } + + return windows_to_posix_errno(last_error); +} + +posix_errno_t efile_make_hard_link(const efile_path_t *existing_path, const efile_path_t *new_path) { + ASSERT_PATH_FORMAT(existing_path); + ASSERT_PATH_FORMAT(new_path); + + if(!CreateHardLinkW((WCHAR*)new_path->data, (WCHAR*)existing_path->data, NULL)) { + return windows_to_posix_errno(GetLastError()); + } + + return 0; +} + +posix_errno_t efile_make_soft_link(const efile_path_t *existing_path, const efile_path_t *new_path) { + DWORD link_flags; + + ASSERT_PATH_FORMAT(existing_path); + ASSERT_PATH_FORMAT(new_path); + + if(has_file_attributes(existing_path, FILE_ATTRIBUTE_DIRECTORY)) { + link_flags = SYMBOLIC_LINK_FLAG_DIRECTORY; + } else { + link_flags = 0; + } + + if(!CreateSymbolicLinkW((WCHAR*)new_path->data, (WCHAR*)existing_path->data, link_flags)) { + return windows_to_posix_errno(GetLastError()); + } + + return 0; +} + +posix_errno_t efile_make_dir(const efile_path_t *path) { + ASSERT_PATH_FORMAT(path); + + if(!CreateDirectoryW((WCHAR*)path->data, NULL)) { + return windows_to_posix_errno(GetLastError()); + } + + return 0; +} + +posix_errno_t efile_del_file(const efile_path_t *path) { + ASSERT_PATH_FORMAT(path); + + if(!DeleteFileW((WCHAR*)path->data)) { + DWORD last_error = GetLastError(); + + switch(last_error) { + case ERROR_INVALID_NAME: + /* Attempted to delete a device or similar. */ + return EACCES; + case ERROR_ACCESS_DENIED: + /* Windows NT reports removing a directory as EACCES instead of + * EPERM. */ + if(has_file_attributes(path, FILE_ATTRIBUTE_DIRECTORY)) { + return EPERM; + } + break; + } + + return windows_to_posix_errno(last_error); + } + + return 0; +} + +posix_errno_t efile_del_dir(const efile_path_t *path) { + ASSERT_PATH_FORMAT(path); + + if(!RemoveDirectoryW((WCHAR*)path->data)) { + DWORD last_error = GetLastError(); + + if(last_error == ERROR_DIRECTORY) { + return ENOTDIR; + } + + return windows_to_posix_errno(last_error); + } + + return 0; +} + +posix_errno_t efile_set_cwd(const efile_path_t *path) { + const WCHAR *path_start; + + ASSERT_PATH_FORMAT(path); + + /* We have to use _wchdir since that's the only function that updates the + * per-drive working directory, but it naively assumes that all paths + * starting with \\ are UNC paths, so we have to skip the \\?\-prefix. */ + path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; + + if(_wchdir(path_start)) { + return windows_to_posix_errno(GetLastError()); + } + + return 0; +} + +static int is_valid_drive(int device_index) { + WCHAR drive_path[4] = {L'?', L':', L'\\', L'\0'}; + + if(device_index == 0) { + /* Default drive; always valid. */ + return 1; + } else if(device_index > (L'Z' - L'A' + 1)) { + return 0; + } + + drive_path[0] = device_index + L'A' - 1; + + switch(GetDriveTypeW(drive_path)) { + case DRIVE_NO_ROOT_DIR: + case DRIVE_UNKNOWN: + return 0; + } + + return 1; +} + +posix_errno_t efile_get_device_cwd(ErlNifEnv *env, int device_index, ERL_NIF_TERM *result) { + ErlNifBinary result_bin; + + /* _wgetdcwd might crash the entire emulator on debug builds since the CRT + * invalid parameter handler asserts if passed a non-existent drive (Or + * simply one that has been unmounted), so we check it ourselves to avoid + * that. */ + if(!is_valid_drive(device_index)) { + return EACCES; + } + + if(!enif_alloc_binary(MAX_PATH * sizeof(WCHAR), &result_bin)) { + return ENOMEM; + } + + if(_wgetdcwd(device_index, (WCHAR*)result_bin.data, MAX_PATH) == NULL) { + enif_release_binary(&result_bin); + return EACCES; + } + + if(!normalize_path_result(&result_bin)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + + (*result) = enif_make_binary(env, &result_bin); + + return 0; +} + +posix_errno_t efile_get_cwd(ErlNifEnv *env, ERL_NIF_TERM *result) { + return efile_get_device_cwd(env, 0, result); +} + +posix_errno_t efile_altname(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TERM *result) { + ErlNifBinary result_bin; + + ASSERT_PATH_FORMAT(path); + + if(is_path_root(path)) { + /* Root paths can't be queried so we'll just return them as they are. */ + if(!enif_alloc_binary(path->size, &result_bin)) { + return ENOMEM; + } + + sys_memcpy(result_bin.data, path->data, path->size); + } else { + WIN32_FIND_DATAW data; + HANDLE handle; + + WCHAR *name_buffer; + int name_length; + + /* Reject path wildcards. */ + if(wcspbrk(&((const WCHAR*)path->data)[4], L"?*")) { + return ENOENT; + } + + handle = FindFirstFileW((const WCHAR*)path->data, &data); + + if(handle == INVALID_HANDLE_VALUE) { + return windows_to_posix_errno(GetLastError()); + } + + FindClose(handle); + + name_length = wcslen(data.cAlternateFileName); + + if(name_length > 0) { + name_buffer = data.cAlternateFileName; + } else { + name_length = wcslen(data.cFileName); + name_buffer = data.cFileName; + } + + /* Include NUL-terminator; it will be removed after normalization. */ + name_length += 1; + + if(!enif_alloc_binary(name_length * sizeof(WCHAR), &result_bin)) { + return ENOMEM; + } + + sys_memcpy(result_bin.data, name_buffer, name_length * sizeof(WCHAR)); + } + + if(!normalize_path_result(&result_bin)) { + enif_release_binary(&result_bin); + return ENOMEM; + } + + (*result) = enif_make_binary(env, &result_bin); + + return 0; +} + +static int windows_to_posix_errno(DWORD last_error) { + switch(last_error) { + case ERROR_SUCCESS: + return 0; + case ERROR_INVALID_FUNCTION: + case ERROR_INVALID_DATA: + case ERROR_INVALID_PARAMETER: + case ERROR_INVALID_TARGET_HANDLE: + case ERROR_INVALID_CATEGORY: + case ERROR_NEGATIVE_SEEK: + return EINVAL; + case ERROR_DIR_NOT_EMPTY: + return EEXIST; + case ERROR_BAD_FORMAT: + return ENOEXEC; + case ERROR_PATH_NOT_FOUND: + case ERROR_FILE_NOT_FOUND: + case ERROR_NO_MORE_FILES: + return ENOENT; + case ERROR_TOO_MANY_OPEN_FILES: + return EMFILE; + case ERROR_ACCESS_DENIED: + case ERROR_INVALID_ACCESS: + case ERROR_CURRENT_DIRECTORY: + case ERROR_SHARING_VIOLATION: + case ERROR_LOCK_VIOLATION: + case ERROR_INVALID_PASSWORD: + case ERROR_DRIVE_LOCKED: + return EACCES; + case ERROR_INVALID_HANDLE: + return EBADF; + case ERROR_NOT_ENOUGH_MEMORY: + case ERROR_OUTOFMEMORY: + case ERROR_OUT_OF_STRUCTURES: + return ENOMEM; + case ERROR_INVALID_DRIVE: + case ERROR_BAD_UNIT: + case ERROR_NOT_READY: + case ERROR_REM_NOT_LIST: + case ERROR_DUP_NAME: + case ERROR_BAD_NETPATH: + case ERROR_NETWORK_BUSY: + case ERROR_DEV_NOT_EXIST: + case ERROR_BAD_NET_NAME: + return ENXIO; + case ERROR_NOT_SAME_DEVICE: + return EXDEV; + case ERROR_WRITE_PROTECT: + return EROFS; + case ERROR_BAD_LENGTH: + case ERROR_BUFFER_OVERFLOW: + return E2BIG; + case ERROR_SEEK: + case ERROR_SECTOR_NOT_FOUND: + return ESPIPE; + case ERROR_NOT_DOS_DISK: + return ENODEV; + case ERROR_GEN_FAILURE: + return ENODEV; + case ERROR_SHARING_BUFFER_EXCEEDED: + case ERROR_NO_MORE_SEARCH_HANDLES: + return EMFILE; + case ERROR_HANDLE_EOF: + case ERROR_BROKEN_PIPE: + return EPIPE; + case ERROR_HANDLE_DISK_FULL: + case ERROR_DISK_FULL: + return ENOSPC; + case ERROR_NOT_SUPPORTED: + return ENOTSUP; + case ERROR_FILE_EXISTS: + case ERROR_ALREADY_EXISTS: + case ERROR_CANNOT_MAKE: + return EEXIST; + case ERROR_ALREADY_ASSIGNED: + return EBUSY; + case ERROR_NO_PROC_SLOTS: + return EAGAIN; + case ERROR_CANT_RESOLVE_FILENAME: + return EMLINK; + case ERROR_PRIVILEGE_NOT_HELD: + return EPERM; + case ERROR_ARENA_TRASHED: + case ERROR_INVALID_BLOCK: + case ERROR_BAD_ENVIRONMENT: + case ERROR_BAD_COMMAND: + case ERROR_CRC: + case ERROR_OUT_OF_PAPER: + case ERROR_READ_FAULT: + case ERROR_WRITE_FAULT: + case ERROR_WRONG_DISK: + case ERROR_NET_WRITE_FAULT: + return EIO; + default: /* not to do with files I expect. */ + return EIO; + } +} |