diff options
Diffstat (limited to 'erts/emulator/sys/unix/sys_drivers.c')
-rw-r--r-- | erts/emulator/sys/unix/sys_drivers.c | 1862 |
1 files changed, 1862 insertions, 0 deletions
diff --git a/erts/emulator/sys/unix/sys_drivers.c b/erts/emulator/sys/unix/sys_drivers.c new file mode 100644 index 0000000000..82fea1b330 --- /dev/null +++ b/erts/emulator/sys/unix/sys_drivers.c @@ -0,0 +1,1862 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 1996-2014. 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% + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#ifdef ISC32 +#define _POSIX_SOURCE +#define _XOPEN_SOURCE +#endif + +#include <sys/times.h> /* ! */ +#include <time.h> +#include <signal.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include <termios.h> +#include <ctype.h> +#include <sys/utsname.h> +#include <sys/select.h> +#include <arpa/inet.h> + +#ifdef ISC32 +#include <sys/bsdtypes.h> +#endif + +#include <termios.h> +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif +#ifdef HAVE_SYS_IOCTL_H +#include <sys/ioctl.h> +#endif + +#define WANT_NONBLOCKING /* must define this to pull in defs from sys.h */ +#include "sys.h" + +#ifdef USE_THREADS +#include "erl_threads.h" +#endif + +extern char **environ; +extern erts_smp_rwmtx_t environ_rwmtx; + +extern erts_smp_atomic_t sys_misc_mem_sz; + +static Eterm forker_port; + +#define MAX_VSIZE 16 /* Max number of entries allowed in an I/O + * vector sock_sendv(). + */ +/* + * Don't need global.h, but erl_cpu_topology.h won't compile otherwise + */ +#include "global.h" +#include "erl_cpu_topology.h" + +#include "erl_sys_driver.h" +#include "sys_uds.h" + +#include "erl_child_setup.h" + +#if defined IOV_MAX +#define MAXIOV IOV_MAX +#elif defined UIO_MAXIOV +#define MAXIOV UIO_MAXIOV +#else +#define MAXIOV 16 +#endif + +#ifdef USE_THREADS +# define FDBLOCK 1 +#else +# define FDBLOCK 0 +#endif + +/* Used by the fd driver iff the fd could not be set to non-blocking */ +typedef struct ErtsSysBlocking_ { + ErlDrvPDL pdl; + int res; + int err; + unsigned int pkey; +} ErtsSysBlocking; + +typedef struct fd_data { + int fd; + char pbuf[4]; /* hold partial packet bytes */ + int psz; /* size of pbuf */ + char *buf; + char *cpos; + int sz; + int remain; /* for input on fd */ +} ErtsSysFdData; + +typedef struct driver_data { + ErlDrvPort port_num; + ErtsSysFdData *ofd; + ErtsSysFdData *ifd; + int packet_bytes; + int pid; + int alive; + int status; + int terminating; + ErtsSysBlocking *blocking; +} ErtsSysDriverData; + +#define DIR_SEPARATOR_CHAR '/' + +#if defined(__ANDROID__) +#define SHELL "/system/bin/sh" +#else +#define SHELL "/bin/sh" +#endif /* __ANDROID__ */ + +#if defined(DEBUG) +#define ERL_BUILD_TYPE_MARKER ".debug" +#elif defined(PURIFY) +#define ERL_BUILD_TYPE_MARKER ".purify" +#elif defined(QUANTIFY) +#define ERL_BUILD_TYPE_MARKER ".quantify" +#elif defined(PURECOV) +#define ERL_BUILD_TYPE_MARKER ".purecov" +#elif defined(VALGRIND) +#define ERL_BUILD_TYPE_MARKER ".valgrind" +#else /* opt */ +#define ERL_BUILD_TYPE_MARKER +#endif + +#ifdef DEBUG +#define close(fd) do { int res = close(fd); ASSERT(res > -1); } while(0) +#endif + +#define CHILD_SETUP_PROG_NAME "erl_child_setup" ERL_BUILD_TYPE_MARKER + +// #define HARD_DEBUG +#ifdef HARD_DEBUG +#define driver_select(port_num, fd, flags, onoff) \ + do { \ + if (((flags) & ERL_DRV_READ) && onoff) \ + fprintf(stderr,"%010d %p: read select %d\r\n", __LINE__, port_num, (int)fd); \ + if (((flags) & ERL_DRV_WRITE) && onoff) \ + fprintf(stderr,"%010d %p: writ select %d\r\n", __LINE__, port_num, (int)fd); \ + if (((flags) & ERL_DRV_READ) && !onoff) \ + fprintf(stderr,"%010d %p: read unsele %d\r\n", __LINE__, port_num, (int)fd); \ + if (((flags) & ERL_DRV_WRITE) && !onoff) \ + fprintf(stderr,"%010d %p: writ unsele %d\r\n", __LINE__, port_num, (int)fd); \ + driver_select_nkp(port_num, fd, flags, onoff); \ + } while(0) +#endif + +/* + * Decreasing the size of it below 16384 is not allowed. + */ + +#define ERTS_SYS_READ_BUF_SZ (64*1024) + +/* I. Initialization */ + +void +erl_sys_late_init(void) +{ + SysDriverOpts opts; +#ifdef ERTS_SMP + Port *port; +#endif + + sys_signal(SIGPIPE, SIG_IGN); /* Ignore - we'll handle the write failure */ + + opts.packet_bytes = 0; + opts.use_stdio = 1; + opts.redir_stderr = 0; + opts.read_write = 0; + opts.hide_window = 0; + opts.wd = NULL; + opts.envir = NULL; + opts.exit_status = 0; + opts.overlapped_io = 0; + opts.spawn_type = ERTS_SPAWN_ANY; + opts.argv = NULL; + opts.parallelism = erts_port_parallelism; + +#ifdef ERTS_SMP + port = +#endif + erts_open_driver(&forker_driver, make_internal_pid(0), "forker", &opts, NULL, NULL); +#ifdef ERTS_SMP + erts_mtx_unlock(port->lock); +#endif +} + +/* II. Prototypes */ + +/* II.I Spawn prototypes */ +static ErlDrvData spawn_start(ErlDrvPort, char*, SysDriverOpts*); +static ErlDrvSSizeT spawn_control(ErlDrvData, unsigned int, char *, + ErlDrvSizeT, char **, ErlDrvSizeT); + +/* II.II Vanilla prototypes */ +static ErlDrvData vanilla_start(ErlDrvPort, char*, SysDriverOpts*); + + +/* II.III FD prototypes */ +static ErlDrvData fd_start(ErlDrvPort, char*, SysDriverOpts*); +#if FDBLOCK +static void fd_async(void *); +static void fd_ready_async(ErlDrvData drv_data, ErlDrvThreadData thread_data); +#endif +static ErlDrvSSizeT fd_control(ErlDrvData, unsigned int, char *, ErlDrvSizeT, + char **, ErlDrvSizeT); +static void fd_stop(ErlDrvData); +static void fd_flush(ErlDrvData); + +/* II.IV Common prototypes */ +static void stop(ErlDrvData); +static void ready_input(ErlDrvData, ErlDrvEvent); +static void ready_output(ErlDrvData, ErlDrvEvent); +static void output(ErlDrvData, char*, ErlDrvSizeT); +static void outputv(ErlDrvData, ErlIOVec*); +static void stop_select(ErlDrvEvent, void*); + +/* II.V Forker prototypes */ +static ErlDrvData forker_start(ErlDrvPort, char*, SysDriverOpts*); +static void forker_stop(ErlDrvData); +static void forker_ready_input(ErlDrvData, ErlDrvEvent); +static void forker_ready_output(ErlDrvData, ErlDrvEvent); +static ErlDrvSSizeT forker_control(ErlDrvData, unsigned int, char *, + ErlDrvSizeT, char **, ErlDrvSizeT); + +/* III Driver entries */ + +/* III.I The spawn driver */ +struct erl_drv_entry spawn_driver_entry = { + NULL, + spawn_start, + stop, + output, + ready_input, + ready_output, + "spawn", + NULL, + NULL, + spawn_control, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + ERL_DRV_EXTENDED_MARKER, + ERL_DRV_EXTENDED_MAJOR_VERSION, + ERL_DRV_EXTENDED_MINOR_VERSION, + ERL_DRV_FLAG_USE_PORT_LOCKING | ERL_DRV_FLAG_USE_INIT_ACK, + NULL, NULL, + stop_select +}; + +/* III.II The fd driver */ +struct erl_drv_entry fd_driver_entry = { + NULL, + fd_start, + fd_stop, + output, + ready_input, + ready_output, + "fd", + NULL, + NULL, + fd_control, + NULL, + outputv, +#if FDBLOCK + fd_ready_async, /* ready_async */ +#else + NULL, +#endif + fd_flush, /* flush */ + NULL, /* call */ + NULL, /* event */ + ERL_DRV_EXTENDED_MARKER, + ERL_DRV_EXTENDED_MAJOR_VERSION, + ERL_DRV_EXTENDED_MINOR_VERSION, + 0, /* ERL_DRV_FLAGs */ + NULL, /* handle2 */ + NULL, /* process_exit */ + stop_select +}; + +/* III.III The vanilla driver */ +struct erl_drv_entry vanilla_driver_entry = { + NULL, + vanilla_start, + stop, + output, + ready_input, + ready_output, + "vanilla", + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, /* flush */ + NULL, /* call */ + NULL, /* event */ + ERL_DRV_EXTENDED_MARKER, + ERL_DRV_EXTENDED_MAJOR_VERSION, + ERL_DRV_EXTENDED_MINOR_VERSION, + 0, /* ERL_DRV_FLAGs */ + NULL, /* handle2 */ + NULL, /* process_exit */ + stop_select +}; + +/* III.III The forker driver */ +struct erl_drv_entry forker_driver_entry = { + NULL, + forker_start, + forker_stop, + NULL, + forker_ready_input, + forker_ready_output, + "spawn_forker", + NULL, + NULL, + forker_control, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL, + ERL_DRV_EXTENDED_MARKER, + ERL_DRV_EXTENDED_MAJOR_VERSION, + ERL_DRV_EXTENDED_MINOR_VERSION, + 0, + NULL, NULL, + stop_select +}; + +/* Untility functions */ + +static int set_blocking_data(ErtsSysDriverData *dd) { + + dd->blocking = erts_alloc(ERTS_ALC_T_SYS_BLOCKING, sizeof(ErtsSysBlocking)); + + erts_smp_atomic_add_nob(&sys_misc_mem_sz, sizeof(ErtsSysBlocking)); + + dd->blocking->pdl = driver_pdl_create(dd->port_num); + dd->blocking->res = 0; + dd->blocking->err = 0; + dd->blocking->pkey = driver_async_port_key(dd->port_num); + + return 1; +} + +static void init_fd_data(ErtsSysFdData *fd_data, int fd) +{ + fd_data->fd = fd; + fd_data->buf = NULL; + fd_data->cpos = NULL; + fd_data->remain = 0; + fd_data->sz = 0; + fd_data->psz = 0; +} + +static ErtsSysDriverData * +create_driver_data(ErlDrvPort port_num, + int ifd, + int ofd, + int packet_bytes, + int read_write, + int exit_status, + int pid, + int is_blocking) +{ + Port *prt; + ErtsSysDriverData *driver_data; + char *data; + int size = sizeof(ErtsSysDriverData); + + if (read_write & DO_READ) + size += sizeof(ErtsSysFdData); + + if ((read_write & DO_WRITE) && + ((ifd != ofd || ofd == -1) || !(read_write & DO_READ))) + size += sizeof(ErtsSysFdData); + + data = erts_alloc(ERTS_ALC_T_DRV_TAB,size); + erts_smp_atomic_add_nob(&sys_misc_mem_sz, size); + + driver_data = (ErtsSysDriverData*)data; + data += sizeof(*driver_data); + + prt = erts_drvport2port(port_num); + if (prt != ERTS_INVALID_ERL_DRV_PORT) + prt->os_pid = pid; + + driver_data->packet_bytes = packet_bytes; + driver_data->port_num = port_num; + driver_data->pid = pid; + driver_data->alive = exit_status ? 1 : 0; + driver_data->status = 0; + driver_data->terminating = 0; + driver_data->blocking = NULL; + + if (read_write & DO_READ) { + driver_data->ifd = (ErtsSysFdData*)data; + data += sizeof(*driver_data->ifd); + init_fd_data(driver_data->ifd, ifd); + driver_select(port_num, ifd, (ERL_DRV_READ|ERL_DRV_USE), 1); + } else { + driver_data->ifd = NULL; + } + + if (read_write & DO_WRITE) { + if (ofd != -1 && ifd == ofd && read_write & DO_READ) { + /* This is for when ifd and ofd are the same fd */ + driver_data->ofd = driver_data->ifd; + } else { + driver_data->ofd = (ErtsSysFdData*)data; + data += sizeof(*driver_data->ofd); + init_fd_data(driver_data->ofd, ofd); + } + if (is_blocking && FDBLOCK) + if (!set_blocking_data(driver_data)) { + erts_free(ERTS_ALC_T_DRV_TAB, driver_data); + return NULL; + } + } else { + driver_data->ofd = NULL; + } + + return driver_data; +} + +/* Spawn driver */ + +static void close_pipes(int ifd[2], int ofd[2]) +{ + close(ifd[0]); + close(ifd[1]); + close(ofd[0]); + close(ofd[1]); +} + +static char **build_unix_environment(char *block) +{ + int i; + int j; + int len; + char *cp; + char **cpp; + char** old_env; + + ERTS_SMP_LC_ASSERT(erts_smp_lc_rwmtx_is_rlocked(&environ_rwmtx)); + + cp = block; + len = 0; + while (*cp != '\0') { + cp += strlen(cp) + 1; + len++; + } + old_env = environ; + while (*old_env++ != NULL) { + len++; + } + + cpp = (char **) erts_alloc_fnf(ERTS_ALC_T_ENVIRONMENT, + sizeof(char *) * (len+1)); + if (cpp == NULL) { + return NULL; + } + + cp = block; + len = 0; + while (*cp != '\0') { + cpp[len] = cp; + cp += strlen(cp) + 1; + len++; + } + + i = len; + for (old_env = environ; *old_env; old_env++) { + char* old = *old_env; + + for (j = 0; j < len; j++) { + char *s, *t; + + /* check if cpp[j] equals old + before the = sign, + i.e. + "TMPDIR=/tmp/" */ + s = cpp[j]; + t = old; + while (*s == *t && *s != '=') { + s++, t++; + } + if (*s == '=' && *t == '=') { + break; + } + } + + if (j == len) { /* New version not found */ + cpp[len++] = old; + } + } + + for (j = 0; j < i; ) { + size_t last = strlen(cpp[j])-1; + if (cpp[j][last] == '=' && strchr(cpp[j], '=') == cpp[j]+last) { + cpp[j] = cpp[--len]; + if (len < i) { + i--; + } else { + j++; + } + } + else { + j++; + } + } + + cpp[len] = NULL; + return cpp; +} + +static ErlDrvData spawn_start(ErlDrvPort port_num, char* name, + SysDriverOpts* opts) +{ +#define CMD_LINE_PREFIX_STR "exec " +#define CMD_LINE_PREFIX_STR_SZ (sizeof(CMD_LINE_PREFIX_STR) - 1) + + int len; + char **new_environ; + ErtsSysDriverData *dd; + char *cmd_line; + char wd_buff[MAXPATHLEN+1]; + char *wd; + int ifd[2], ofd[2], stderrfd; + + if (pipe(ifd) < 0) return ERL_DRV_ERROR_ERRNO; + errno = EMFILE; /* default for next three conditions */ + if (ifd[0] >= sys_max_files() || pipe(ofd) < 0) { + close(ifd[0]); + close(ifd[1]); + return ERL_DRV_ERROR_ERRNO; + } + if (ofd[1] >= sys_max_files()) { + close_pipes(ifd, ofd); + errno = EMFILE; + return ERL_DRV_ERROR_ERRNO; + } + + SET_NONBLOCKING(ifd[0]); + SET_NONBLOCKING(ofd[1]); + + stderrfd = opts->redir_stderr ? ifd[1] : dup(2); + + if (stderrfd >= sys_max_files() || stderrfd < 0) { + close_pipes(ifd, ofd); + if (stderrfd > -1) + close(stderrfd); + return ERL_DRV_ERROR_ERRNO; + } + + if (opts->spawn_type == ERTS_SPAWN_EXECUTABLE) { + /* started with spawn_executable, not with spawn */ + len = strlen(name); + cmd_line = (char *) erts_alloc_fnf(ERTS_ALC_T_TMP, len + 1); + if (!cmd_line) { + close_pipes(ifd, ofd); + errno = ENOMEM; + return ERL_DRV_ERROR_ERRNO; + } + memcpy((void *) cmd_line,(void *) name, len); + cmd_line[len] = '\0'; + len = len + 1; + if (access(cmd_line,X_OK) != 0) { + int save_errno = errno; + erts_free(ERTS_ALC_T_TMP, cmd_line); + close_pipes(ifd, ofd); + errno = save_errno; + return ERL_DRV_ERROR_ERRNO; + } + } else { + /* make the string suitable for giving to "sh" */ + len = strlen(name); + cmd_line = (char *) erts_alloc_fnf(ERTS_ALC_T_TMP, + CMD_LINE_PREFIX_STR_SZ + len + 1); + if (!cmd_line) { + close_pipes(ifd, ofd); + errno = ENOMEM; + return ERL_DRV_ERROR_ERRNO; + } + memcpy((void *) cmd_line, + (void *) CMD_LINE_PREFIX_STR, + CMD_LINE_PREFIX_STR_SZ); + memcpy((void *) (cmd_line + CMD_LINE_PREFIX_STR_SZ), (void *) name, len); + cmd_line[CMD_LINE_PREFIX_STR_SZ + len] = '\0'; + len = CMD_LINE_PREFIX_STR_SZ + len + 1; + } + + erts_smp_rwmtx_rlock(&environ_rwmtx); + + if (opts->envir == NULL) { + new_environ = environ; + } else if ((new_environ = build_unix_environment(opts->envir)) == NULL) { + erts_smp_rwmtx_runlock(&environ_rwmtx); + close_pipes(ifd, ofd); + erts_free(ERTS_ALC_T_TMP, (void *) cmd_line); + errno = ENOMEM; + return ERL_DRV_ERROR_ERRNO; + } + + if (opts->wd == NULL) { + if ((wd = getcwd(wd_buff, MAXPATHLEN+1)) == NULL) { + /* on some OSs this call opens a fd in the + background which means that this can + return EMFILE */ + int err = errno; + close_pipes(ifd, ofd); + erts_free(ERTS_ALC_T_TMP, (void *) cmd_line); + if (new_environ != environ) + erts_free(ERTS_ALC_T_ENVIRONMENT, (void *) new_environ); + erts_smp_rwmtx_runlock(&environ_rwmtx); + errno = err; + return ERL_DRV_ERROR_ERRNO; + } + } else { + wd = opts->wd; + } + + { + struct iovec *io_vector; + int iov_len = 5; + char nullbuff[] = "\0"; + int j, i = 0, res; + Sint32 buffsz = 0, env_len = 0, argv_len = 0, + flags = (opts->use_stdio ? FORKER_FLAG_USE_STDIO : 0) + | (opts->exit_status ? FORKER_FLAG_EXIT_STATUS : 0) + | (opts->read_write & DO_READ ? FORKER_FLAG_DO_READ : 0) + | (opts->read_write & DO_WRITE ? FORKER_FLAG_DO_WRITE : 0); + + /* count number of elements in environment */ + while(new_environ[env_len] != NULL) + env_len++; + iov_len += 1 + env_len; /* num envs including size int */ + + /* count number of element in argument list */ + if (opts->spawn_type == ERTS_SPAWN_EXECUTABLE) { + if (opts->argv != NULL) { + while(opts->argv[argv_len] != NULL) + argv_len++; + } else { + argv_len++; + } + iov_len += 1 + argv_len; /* num argvs including size int */ + } + + io_vector = erts_alloc_fnf(ERTS_ALC_T_TMP, sizeof(struct iovec) * iov_len); + + if (!io_vector) { + close_pipes(ifd, ofd); + erts_smp_rwmtx_runlock(&environ_rwmtx); + erts_free(ERTS_ALC_T_TMP, (void *) cmd_line); + if (new_environ != environ) + erts_free(ERTS_ALC_T_ENVIRONMENT, (void *) new_environ); + errno = ENOMEM; + return ERL_DRV_ERROR_ERRNO; + } + + io_vector[i].iov_base = (void*)&buffsz; + io_vector[i++].iov_len = sizeof(buffsz); + + io_vector[i].iov_base = (void*)&flags; + flags = htonl(flags); + io_vector[i++].iov_len = sizeof(flags); + buffsz += sizeof(flags); + + io_vector[i].iov_base = cmd_line; + io_vector[i++].iov_len = len; + buffsz += len; + + io_vector[i].iov_base = wd; + io_vector[i].iov_len = strlen(io_vector[i].iov_base) + 1; + buffsz += io_vector[i++].iov_len; + + io_vector[i].iov_base = nullbuff; + io_vector[i++].iov_len = 1; + buffsz += io_vector[i-1].iov_len; + + io_vector[i].iov_base = (void*)&env_len; + env_len = htonl(env_len); + io_vector[i++].iov_len = sizeof(env_len); + buffsz += io_vector[i-1].iov_len; + + for (j = 0; new_environ[j] != NULL; j++) { + io_vector[i].iov_base = new_environ[j]; + io_vector[i++].iov_len = strlen(new_environ[j]) + 1; + buffsz += io_vector[i-1].iov_len; + } + + /* only append arguments if this was a spawn_executable */ + if (opts->spawn_type == ERTS_SPAWN_EXECUTABLE) { + + io_vector[i].iov_base = (void*)&argv_len; + argv_len = htonl(argv_len); + io_vector[i++].iov_len = sizeof(argv_len); + buffsz += io_vector[i-1].iov_len; + + if (opts->argv) { + /* If there are arguments we copy in the references to + them into the iov */ + for (j = 0; opts->argv[j]; j++) { + if (opts->argv[j] == erts_default_arg0) + io_vector[i].iov_base = cmd_line; + else + io_vector[i].iov_base = opts->argv[j]; + io_vector[i].iov_len = strlen(io_vector[i].iov_base) + 1; + buffsz += io_vector[i++].iov_len; + } + } else { + io_vector[i].iov_base = cmd_line; + io_vector[i].iov_len = strlen(io_vector[i].iov_base) + 1; + buffsz += io_vector[i++].iov_len; + } + } + + /* we send the request to do the fork */ + if ((res = writev(ofd[1], io_vector, iov_len > MAXIOV ? MAXIOV : iov_len)) < 0) { + if (errno == ERRNO_BLOCK) { + res = 0; + } else { + int err = errno; + close_pipes(ifd, ofd); + erts_free(ERTS_ALC_T_TMP, io_vector); + if (new_environ != environ) + erts_free(ERTS_ALC_T_ENVIRONMENT, (void *) new_environ); + erts_smp_rwmtx_runlock(&environ_rwmtx); + erts_free(ERTS_ALC_T_TMP, (void *) cmd_line); + errno = err; + return ERL_DRV_ERROR_ERRNO; + } + } + + if (res < buffsz) { + /* we only wrote part of the command payload. Enqueue the rest. */ + for (i = 0; i < iov_len; i++) { + driver_enq(port_num, io_vector[i].iov_base, io_vector[i].iov_len); + } + driver_deq(port_num, res); + driver_select(port_num, ofd[1], ERL_DRV_WRITE|ERL_DRV_USE, 1); + } + + erts_free(ERTS_ALC_T_TMP, io_vector); + } + + erts_free(ERTS_ALC_T_TMP, (void *) cmd_line); + + if (new_environ != environ) + erts_free(ERTS_ALC_T_ENVIRONMENT, (void *) new_environ); + + erts_smp_rwmtx_runlock(&environ_rwmtx); + + dd = create_driver_data(port_num, ifd[0], ofd[1], opts->packet_bytes, + DO_WRITE | DO_READ, opts->exit_status, + 0, 0); + + { + /* send ofd[0] + ifd[1] + stderrfd to forker port */ + ErtsSysForkerProto *proto = + erts_alloc(ERTS_ALC_T_DRV_CTRL_DATA, + sizeof(ErtsSysForkerProto)); + memset(proto, 0, sizeof(ErtsSysForkerProto)); + proto->action = ErtsSysForkerProtoAction_Start; + proto->u.start.fds[0] = ofd[0]; + proto->u.start.fds[1] = ifd[1]; + proto->u.start.fds[2] = stderrfd; + proto->u.start.port_id = opts->exit_status ? erts_drvport2id(port_num) : THE_NON_VALUE; + if (erl_drv_port_control(forker_port, 'S', (char*)proto, sizeof(*proto))) { + /* The forker port has been killed, we close both fd's which will + make open_port throw an epipe error */ + close(ofd[0]); + close(ifd[1]); + } + } + + /* we set these fds to negative to mark if + they should be closed after the handshake */ + if (!(opts->read_write & DO_READ)) + dd->ifd->fd *= -1; + + if (!(opts->read_write & DO_WRITE)) + dd->ofd->fd *= -1; + + return (ErlDrvData)dd; +#undef CMD_LINE_PREFIX_STR +#undef CMD_LINE_PREFIX_STR_SZ +} + +static ErlDrvSSizeT spawn_control(ErlDrvData e, unsigned int cmd, char *buf, + ErlDrvSizeT len, char **rbuf, ErlDrvSizeT rlen) +{ + ErtsSysDriverData *dd = (ErtsSysDriverData*)e; + ErtsSysForkerProto *proto = (ErtsSysForkerProto *)buf; + + ASSERT(len == sizeof(*proto)); + ASSERT(proto->action == ErtsSysForkerProtoAction_SigChld); + + dd->status = proto->u.sigchld.error_number; + dd->alive = -1; + + if (dd->ifd) + driver_select(dd->port_num, abs(dd->ifd->fd), ERL_DRV_READ | ERL_DRV_USE, 1); + + if (dd->ofd) + driver_select(dd->port_num, abs(dd->ofd->fd), ERL_DRV_WRITE | ERL_DRV_USE, 1); + + return 0; +} + +#define FD_DEF_HEIGHT 24 +#define FD_DEF_WIDTH 80 +/* Control op */ +#define FD_CTRL_OP_GET_WINSIZE 100 + +static int fd_get_window_size(int fd, Uint32 *width, Uint32 *height) +{ +#ifdef TIOCGWINSZ + struct winsize ws; + if (ioctl(fd,TIOCGWINSZ,&ws) == 0) { + *width = (Uint32) ws.ws_col; + *height = (Uint32) ws.ws_row; + return 0; + } +#endif + return -1; +} + +static ErlDrvSSizeT fd_control(ErlDrvData drv_data, + unsigned int command, + char *buf, ErlDrvSizeT len, + char **rbuf, ErlDrvSizeT rlen) +{ + int fd = (int)(long)drv_data; + char resbuff[2*sizeof(Uint32)]; + switch (command) { + case FD_CTRL_OP_GET_WINSIZE: + { + Uint32 w,h; + if (fd_get_window_size(fd,&w,&h)) + return 0; + memcpy(resbuff,&w,sizeof(Uint32)); + memcpy(resbuff+sizeof(Uint32),&h,sizeof(Uint32)); + } + break; + default: + return 0; + } + if (rlen < 2*sizeof(Uint32)) { + *rbuf = driver_alloc(2*sizeof(Uint32)); + } + memcpy(*rbuf,resbuff,2*sizeof(Uint32)); + return 2*sizeof(Uint32); +} + +static ErlDrvData fd_start(ErlDrvPort port_num, char* name, + SysDriverOpts* opts) +{ + int non_blocking = 0; + + if (((opts->read_write & DO_READ) && opts->ifd >= sys_max_files()) || + ((opts->read_write & DO_WRITE) && opts->ofd >= sys_max_files())) + return ERL_DRV_ERROR_GENERAL; + + /* + * Historical: + * + * "Note about nonblocking I/O. + * + * At least on Solaris, setting the write end of a TTY to nonblocking, + * will set the input end to nonblocking as well (and vice-versa). + * If erl is run in a pipeline like this: cat | erl + * the input end of the TTY will be the standard input of cat. + * And cat is not prepared to handle nonblocking I/O." + * + * Actually, the reason for this is not that the tty itself gets set + * in non-blocking mode, but that the "input end" (cat's stdin) and + * the "output end" (erlang's stdout) are typically the "same" file + * descriptor, dup()'ed from a single fd by one of this process' + * ancestors. + * + * The workaround for this problem used to be a rather bad kludge, + * interposing an extra process ("internal cat") between erlang's + * stdout and the original stdout, allowing erlang to set its stdout + * in non-blocking mode without affecting the stdin of the preceding + * process in the pipeline - and being a kludge, it caused all kinds + * of weird problems. + * + * So, this is the current logic: + * + * The only reason to set non-blocking mode on the output fd at all is + * if it's something that can cause a write() to block, of course, + * i.e. primarily if it points to a tty, socket, pipe, or fifo. + * + * If we don't set non-blocking mode when we "should" have, and output + * becomes blocked, the entire runtime system will be suspended - this + * is normally bad of course, and can happen fairly "easily" - e.g. user + * hits ^S on tty - but doesn't necessarily happen. + * + * If we do set non-blocking mode when we "shouldn't" have, the runtime + * system will end up seeing EOF on the input fd (due to the preceding + * process dying), which typically will cause the entire runtime system + * to terminate immediately (due to whatever erlang process is seeing + * the EOF taking it as a signal to halt the system). This is *very* bad. + * + * I.e. we should take a conservative approach, and only set non- + * blocking mode when we a) need to, and b) are reasonably certain + * that it won't be a problem. And as in the example above, the problem + * occurs when input fd and output fd point to different "things". + * + * However, determining that they are not just the same "type" of + * "thing", but actually the same instance of that type of thing, is + * unreasonably complex in many/most cases. + * + * Also, with pipes, sockets, and fifos it's far from obvious that the + * user *wants* non-blocking output: If you're running erlang inside + * some complex pipeline, you're probably not running a real-time system + * that must never stop, but rather *want* it to suspend if the output + * channel is "full". + * + * So, the bottom line: We will only set the output fd non-blocking if + * it points to a tty, and either a) the input fd also points to a tty, + * or b) we can make sure that setting the output fd non-blocking + * doesn't interfere with someone else's input, via a somewhat milder + * kludge than the above. + * + * Also keep in mind that while this code is almost exclusively run as + * a result of an erlang open_port({fd,0,1}, ...), that isn't the only + * case - it can be called with any old pre-existing file descriptors, + * the relations between which (if they're even two) we can only guess + * at - still, we try our best... + * + * Added note OTP 18: Some systems seem to use stdout/stderr to log data + * using unix pipes, so we cannot allow the system to block on a write. + * Therefore we use an async thread to write the data to fd's that could + * not be set to non-blocking. When no async threads are available we + * fall back on the old behaviour. + * + * Also the guarantee about what is delivered to the OS has changed. + * Pre 18 the fd driver did no flushing of data before terminating. + * Now it does. This is because we want to be able to guarantee that things + * such as escripts and friends really have outputted all data before + * terminating. This could potentially block the termination of the system + * for a very long time, but if the user wants to terminate fast she should + * use erlang:halt with flush=false. + */ + + /* Try to figure out if we can use non-blocking writes */ + if (opts->read_write & DO_WRITE) { + + /* If we don't have a read end, all bets are off - no non-blocking. */ + if (opts->read_write & DO_READ) { + + if (isatty(opts->ofd)) { /* output fd is a tty:-) */ + + if (isatty(opts->ifd)) { /* input fd is also a tty */ + + /* To really do this "right", we should also check that + input and output fd point to the *same* tty - but + this seems like overkill; ttyname() isn't for free, + and this is a very common case - and it's hard to + imagine a scenario where setting non-blocking mode + here would cause problems - go ahead and do it. */ + + non_blocking = 1; + SET_NONBLOCKING(opts->ofd); + + } else { /* output fd is a tty, input fd isn't */ + + /* This is a "problem case", but also common (see the + example above) - i.e. it makes sense to try a bit + harder before giving up on non-blocking mode: Try to + re-open the tty that the output fd points to, and if + successful replace the original one with the "new" fd + obtained this way, and set *that* one in non-blocking + mode. (Yes, this is a kludge.) + + However, re-opening the tty may fail in a couple of + (unusual) cases: + + 1) The name of the tty (or an equivalent one, i.e. + same major/minor number) can't be found, because + it actually lives somewhere other than /dev (or + wherever ttyname() looks for it), and isn't + equivalent to any of those that do live in the + "standard" place - this should be *very* unusual. + + 2) Permissions on the tty don't allow us to open it - + it's perfectly possible to have an fd open to an + object whose permissions wouldn't allow us to open + it. This is not as unusual as it sounds, one case + is if the user has su'ed to someone else (not + root) - we have a read/write fd open to the tty + (because it has been inherited all the way down + here), but we have neither read nor write + permission for the tty. + + In these cases, we finally give up, and don't set the + output fd in non-blocking mode. */ + + char *tty; + int nfd; + + if ((tty = ttyname(opts->ofd)) != NULL && + (nfd = open(tty, O_WRONLY)) != -1) { + dup2(nfd, opts->ofd); + close(nfd); + non_blocking = 1; + SET_NONBLOCKING(opts->ofd); + } + } + } + } + } + return (ErlDrvData)create_driver_data(port_num, opts->ifd, opts->ofd, + opts->packet_bytes, + opts->read_write, 0, -1, + !non_blocking); +} + +static void clear_fd_data(ErtsSysFdData *fdd) +{ + if (fdd->sz > 0) { + erts_free(ERTS_ALC_T_FD_ENTRY_BUF, (void *) fdd->buf); + ASSERT(erts_smp_atomic_read_nob(&sys_misc_mem_sz) >= fdd->sz); + erts_smp_atomic_add_nob(&sys_misc_mem_sz, -1*fdd->sz); + } + fdd->buf = NULL; + fdd->sz = 0; + fdd->remain = 0; + fdd->cpos = NULL; + fdd->psz = 0; +} + +static void nbio_stop_fd(ErlDrvPort prt, ErtsSysFdData *fdd) +{ + driver_select(prt, abs(fdd->fd), DO_READ|DO_WRITE, 0); + clear_fd_data(fdd); + SET_BLOCKING(abs(fdd->fd)); + +} + +static void fd_stop(ErlDrvData ev) /* Does not close the fds */ +{ + ErtsSysDriverData* dd = (ErtsSysDriverData*)ev; + ErlDrvPort prt = dd->port_num; + int sz = sizeof(ErtsSysDriverData); + +#if FDBLOCK + if (dd->blocking) { + erts_free(ERTS_ALC_T_SYS_BLOCKING, dd->blocking); + dd->blocking = NULL; + sz += sizeof(ErtsSysBlocking); + } +#endif + + if (dd->ifd) { + sz += sizeof(ErtsSysFdData); + nbio_stop_fd(prt, dd->ifd); + } + if (dd->ofd && dd->ofd != dd->ifd) { + sz += sizeof(ErtsSysFdData); + nbio_stop_fd(prt, dd->ofd); + } + + erts_free(ERTS_ALC_T_DRV_TAB, dd); + erts_smp_atomic_add_nob(&sys_misc_mem_sz, -sz); +} + +static void fd_flush(ErlDrvData ev) +{ + ErtsSysDriverData* dd = (ErtsSysDriverData*)ev; + if (!dd->terminating) + dd->terminating = 1; +} + +static ErlDrvData vanilla_start(ErlDrvPort port_num, char* name, + SysDriverOpts* opts) +{ + int flags, fd; + ErlDrvData res; + + flags = (opts->read_write == DO_READ ? O_RDONLY : + opts->read_write == DO_WRITE ? O_WRONLY|O_CREAT|O_TRUNC : + O_RDWR|O_CREAT); + if ((fd = open(name, flags, 0666)) < 0) + return ERL_DRV_ERROR_GENERAL; + if (fd >= sys_max_files()) { + close(fd); + return ERL_DRV_ERROR_GENERAL; + } + SET_NONBLOCKING(fd); + + res = (ErlDrvData)(long)create_driver_data(port_num, fd, fd, + opts->packet_bytes, + opts->read_write, 0, -1, 0); + return res; +} + +/* Note that driver_data[fd].ifd == fd if the port was opened for reading, */ +/* otherwise (i.e. write only) driver_data[fd].ofd = fd. */ + +static void stop(ErlDrvData ev) +{ + ErtsSysDriverData* dd = (ErtsSysDriverData*)ev; + ErlDrvPort prt = dd->port_num; + + if (dd->ifd) { + nbio_stop_fd(prt, dd->ifd); + driver_select(prt, abs(dd->ifd->fd), ERL_DRV_USE, 0); /* close(ifd); */ + } + + if (dd->ofd && dd->ofd != dd->ifd) { + nbio_stop_fd(prt, dd->ofd); + driver_select(prt, abs(dd->ofd->fd), ERL_DRV_USE, 0); /* close(ofd); */ + } + + erts_free(ERTS_ALC_T_DRV_TAB, dd); +} + +/* used by fd_driver */ +static void outputv(ErlDrvData e, ErlIOVec* ev) +{ + ErtsSysDriverData *dd = (ErtsSysDriverData*)e; + ErlDrvPort ix = dd->port_num; + int pb = dd->packet_bytes; + int ofd = dd->ofd ? dd->ofd->fd : -1; + ssize_t n; + ErlDrvSizeT sz; + char lb[4]; + char* lbp; + ErlDrvSizeT len = ev->size; + + /* (len > ((unsigned long)-1 >> (4-pb)*8)) */ + /* if (pb >= 0 && (len & (((ErlDrvSizeT)1 << (pb*8))) - 1) != len) {*/ + if (((pb == 2) && (len > 0xffff)) || (pb == 1 && len > 0xff)) { + driver_failure_posix(ix, EINVAL); + return; /* -1; */ + } + /* Handles 0 <= pb <= 4 only */ + put_int32((Uint32) len, lb); + lbp = lb + (4-pb); + + ev->iov[0].iov_base = lbp; + ev->iov[0].iov_len = pb; + ev->size += pb; + + if (dd->blocking && FDBLOCK) + driver_pdl_lock(dd->blocking->pdl); + + if ((sz = driver_sizeq(ix)) > 0) { + driver_enqv(ix, ev, 0); + + if (dd->blocking && FDBLOCK) + driver_pdl_unlock(dd->blocking->pdl); + + if (sz + ev->size >= (1 << 13)) + set_busy_port(ix, 1); + } + else if (!dd->blocking || !FDBLOCK) { + /* We try to write directly if the fd in non-blocking */ + int vsize = ev->vsize > MAX_VSIZE ? MAX_VSIZE : ev->vsize; + + n = writev(ofd, (const void *) (ev->iov), vsize); + if (n == ev->size) + return; /* 0;*/ + if (n < 0) { + if ((errno != EINTR) && (errno != ERRNO_BLOCK)) { + driver_failure_posix(ix, errno); + return; /* -1;*/ + } + n = 0; + } + driver_enqv(ix, ev, n); /* n is the skip value */ + driver_select(ix, ofd, ERL_DRV_WRITE|ERL_DRV_USE, 1); + } +#if FDBLOCK + else { + if (ev->size != 0) { + driver_enqv(ix, ev, 0); + driver_pdl_unlock(dd->blocking->pdl); + driver_async(ix, &dd->blocking->pkey, + fd_async, dd, NULL); + } else { + driver_pdl_unlock(dd->blocking->pdl); + } + } +#endif + /* return 0;*/ +} + +/* Used by spawn_driver and vanilla driver */ +static void output(ErlDrvData e, char* buf, ErlDrvSizeT len) +{ + ErtsSysDriverData *dd = (ErtsSysDriverData*)e; + ErlDrvPort ix = dd->port_num; + int pb = dd->packet_bytes; + int ofd = dd->ofd ? dd->ofd->fd : -1; + ssize_t n; + ErlDrvSizeT sz; + char lb[4]; + char* lbp; + struct iovec iv[2]; + + /* (len > ((unsigned long)-1 >> (4-pb)*8)) */ + if (((pb == 2) && (len > 0xffff)) + || (pb == 1 && len > 0xff) + || dd->pid == 0 /* Attempt at output before port is ready */) { + driver_failure_posix(ix, EINVAL); + return; /* -1; */ + } + put_int32(len, lb); + lbp = lb + (4-pb); + + if ((sz = driver_sizeq(ix)) > 0) { + driver_enq(ix, lbp, pb); + driver_enq(ix, buf, len); + if (sz + len + pb >= (1 << 13)) + set_busy_port(ix, 1); + } + else { + iv[0].iov_base = lbp; + iv[0].iov_len = pb; /* should work for pb=0 */ + iv[1].iov_base = buf; + iv[1].iov_len = len; + n = writev(ofd, iv, 2); + if (n == pb+len) + return; /* 0; */ + if (n < 0) { + if ((errno != EINTR) && (errno != ERRNO_BLOCK)) { + driver_failure_posix(ix, errno); + return; /* -1; */ + } + n = 0; + } + if (n < pb) { + driver_enq(ix, lbp+n, pb-n); + driver_enq(ix, buf, len); + } + else { + n -= pb; + driver_enq(ix, buf+n, len-n); + } + driver_select(ix, ofd, ERL_DRV_WRITE|ERL_DRV_USE, 1); + } + return; /* 0; */ +} + +static int port_inp_failure(ErtsSysDriverData *dd, int res) + /* Result: 0 (eof) or -1 (error) */ +{ + int err = errno; + + ASSERT(res <= 0); + if (dd->ifd) { + driver_select(dd->port_num, dd->ifd->fd, ERL_DRV_READ|ERL_DRV_WRITE, 0); + clear_fd_data(dd->ifd); + } + + if (dd->blocking && FDBLOCK) { + driver_pdl_lock(dd->blocking->pdl); + if (driver_sizeq(dd->port_num) > 0) { + driver_pdl_unlock(dd->blocking->pdl); + /* We have stuff in the output queue, so we just + set the state to terminating and wait for fd_async_ready + to terminate the port */ + if (res == 0) + dd->terminating = 2; + else + dd->terminating = -err; + return 0; + } + driver_pdl_unlock(dd->blocking->pdl); + } + + if (res == 0) { + if (dd->alive == 1) { + /* + * We have eof and want to report exit status, but the process + * hasn't exited yet. When it does ready_input will + * driver_select() this fd which will make sure that we get + * back here with dd->alive == -1 and dd->status set. + */ + return 0; + } + else if (dd->alive == -1) { + int status = dd->status; + + /* We need not be prepared for stopped/continued processes. */ + if (WIFSIGNALED(status)) + status = 128 + WTERMSIG(status); + else + status = WEXITSTATUS(status); + driver_report_exit(dd->port_num, status); + } + driver_failure_eof(dd->port_num); + } else if (dd->ifd) { + erl_drv_init_ack(dd->port_num, ERL_DRV_ERROR_ERRNO); + } else { + driver_failure_posix(dd->port_num, err); + } + return 0; +} + +/* fd is the drv_data that is returned from the */ +/* initial start routine */ +/* ready_fd is the descriptor that is ready to read */ + +static void ready_input(ErlDrvData e, ErlDrvEvent ready_fd) +{ + ErtsSysDriverData *dd = (ErtsSysDriverData*)e; + ErlDrvPort port_num; + int packet_bytes; + int res; + Uint h; + + port_num = dd->port_num; + packet_bytes = dd->packet_bytes; + + ASSERT(abs(dd->ifd->fd) == ready_fd); + + if (dd->pid == 0) { + /* the pid is sent from erl_child_setup. spawn driver only. */ + ErtsSysForkerProto proto; + int res; + + if((res = read(ready_fd, &proto, sizeof(proto))) <= 0) { + /* hmm, child setup seems to have closed the pipe too early... + we close the port as there is not much else we can do */ + if (res < 0 && errno == ERRNO_BLOCK) + return; + driver_select(port_num, ready_fd, ERL_DRV_READ, 0); + if (res == 0) + errno = EPIPE; + port_inp_failure(dd, -1); + return; + } + + ASSERT(proto.action == ErtsSysForkerProtoAction_Go); + dd->pid = proto.u.go.os_pid; + + if (dd->pid == -1) { + /* Setup failed! The only reason why this should happen is if + the fork fails. */ + errno = proto.u.go.error_number; + port_inp_failure(dd, -1); + return; + } + + proto.action = ErtsSysForkerProtoAction_Ack; + + if (driver_sizeq(port_num) > 0) { + driver_enq(port_num, (char*)&proto, sizeof(proto)); + } else { + if (write(abs(dd->ofd->fd), &proto, sizeof(proto)) < 0) + if (errno == ERRNO_BLOCK || errno == EINTR) + driver_enq(port_num, (char*)&proto, sizeof(proto)); + /* do nothing on failure here. If the ofd is broken, then + the ifd will probably also be broken and trigger + a port_inp_failure */ + } + + if (dd->ifd->fd < 0) { + driver_select(port_num, abs(dd->ifd->fd), ERL_DRV_READ|ERL_DRV_USE, 0); + erts_smp_atomic_add_nob(&sys_misc_mem_sz, -sizeof(ErtsSysFdData)); + dd->ifd = NULL; + } + + if (dd->ofd->fd < 0 || driver_sizeq(port_num) > 0) + /* we select in order to close fd or write to queue, + child setup will close this fd if fd < 0 */ + driver_select(port_num, abs(dd->ofd->fd), ERL_DRV_WRITE|ERL_DRV_USE, 1); + + erl_drv_set_os_pid(port_num, dd->pid); + erl_drv_init_ack(port_num, e); + return; + } + + if (packet_bytes == 0) { + byte *read_buf = (byte *) erts_alloc(ERTS_ALC_T_SYS_READ_BUF, + ERTS_SYS_READ_BUF_SZ); + res = read(ready_fd, read_buf, ERTS_SYS_READ_BUF_SZ); + if (res < 0) { + if ((errno != EINTR) && (errno != ERRNO_BLOCK)) + port_inp_failure(dd, res); + } + else if (res == 0) + port_inp_failure(dd, res); + else + driver_output(port_num, (char*) read_buf, res); + erts_free(ERTS_ALC_T_SYS_READ_BUF, (void *) read_buf); + } + else if (dd->ifd->remain > 0) { /* We try to read the remainder */ + /* space is allocated in buf */ + res = read(ready_fd, dd->ifd->cpos, + dd->ifd->remain); + if (res < 0) { + if ((errno != EINTR) && (errno != ERRNO_BLOCK)) + port_inp_failure(dd, res); + } + else if (res == 0) { + port_inp_failure(dd, res); + } + else if (res == dd->ifd->remain) { /* we're done */ + driver_output(port_num, dd->ifd->buf, + dd->ifd->sz); + clear_fd_data(dd->ifd); + } + else { /* if (res < dd->ifd->remain) */ + dd->ifd->cpos += res; + dd->ifd->remain -= res; + } + } + else if (dd->ifd->remain == 0) { /* clean fd */ + byte *read_buf = (byte *) erts_alloc(ERTS_ALC_T_SYS_READ_BUF, + ERTS_SYS_READ_BUF_SZ); + /* We make one read attempt and see what happens */ + res = read(ready_fd, read_buf, ERTS_SYS_READ_BUF_SZ); + if (res < 0) { + if ((errno != EINTR) && (errno != ERRNO_BLOCK)) + port_inp_failure(dd, res); + } + else if (res == 0) { /* eof */ + port_inp_failure(dd, res); + } + else if (res < packet_bytes - dd->ifd->psz) { + memcpy(dd->ifd->pbuf+dd->ifd->psz, + read_buf, res); + dd->ifd->psz += res; + } + else { /* if (res >= packet_bytes) */ + unsigned char* cpos = read_buf; + int bytes_left = res; + + while (1) { + int psz = dd->ifd->psz; + char* pbp = dd->ifd->pbuf + psz; + + while(bytes_left && (psz < packet_bytes)) { + *pbp++ = *cpos++; + bytes_left--; + psz++; + } + + if (psz < packet_bytes) { + dd->ifd->psz = psz; + break; + } + dd->ifd->psz = 0; + + switch (packet_bytes) { + case 1: h = get_int8(dd->ifd->pbuf); break; + case 2: h = get_int16(dd->ifd->pbuf); break; + case 4: h = get_int32(dd->ifd->pbuf); break; + default: ASSERT(0); return; /* -1; */ + } + + if (h <= (bytes_left)) { + driver_output(port_num, (char*) cpos, h); + cpos += h; + bytes_left -= h; + continue; + } + else { /* The last message we got was split */ + char *buf = erts_alloc_fnf(ERTS_ALC_T_FD_ENTRY_BUF, h); + if (!buf) { + errno = ENOMEM; + port_inp_failure(dd, -1); + } + else { + erts_smp_atomic_add_nob(&sys_misc_mem_sz, h); + sys_memcpy(buf, cpos, bytes_left); + dd->ifd->buf = buf; + dd->ifd->sz = h; + dd->ifd->remain = h - bytes_left; + dd->ifd->cpos = buf + bytes_left; + } + break; + } + } + } + erts_free(ERTS_ALC_T_SYS_READ_BUF, (void *) read_buf); + } +} + + +/* fd is the drv_data that is returned from the */ +/* initial start routine */ +/* ready_fd is the descriptor that is ready to read */ + +static void ready_output(ErlDrvData e, ErlDrvEvent ready_fd) +{ + ErtsSysDriverData *dd = (ErtsSysDriverData*)e; + ErlDrvPort ix = dd->port_num; + int n; + struct iovec* iv; + int vsize; + + if ((iv = (struct iovec*) driver_peekq(ix, &vsize)) == NULL) { + driver_select(ix, ready_fd, ERL_DRV_WRITE, 0); + if (dd->pid > 0 && dd->ofd->fd < 0) { + /* The port was opened with 'in' option, which means we + should close the output fd as soon as the command has + been sent. */ + driver_select(ix, ready_fd, ERL_DRV_WRITE|ERL_DRV_USE, 0); + erts_smp_atomic_add_nob(&sys_misc_mem_sz, -sizeof(ErtsSysFdData)); + dd->ofd = NULL; + } + if (dd->terminating) + driver_failure_atom(dd->port_num,"normal"); + return; /* 0; */ + } + vsize = vsize > MAX_VSIZE ? MAX_VSIZE : vsize; + if ((n = writev(ready_fd, iv, vsize)) > 0) { + if (driver_deq(ix, n) == 0) + set_busy_port(ix, 0); + } + else if (n < 0) { + if (errno == ERRNO_BLOCK || errno == EINTR) + return; /* 0; */ + else { + int res = errno; + driver_select(ix, ready_fd, ERL_DRV_WRITE, 0); + driver_failure_posix(ix, res); + return; /* -1; */ + } + } + return; /* 0; */ +} + +static void stop_select(ErlDrvEvent fd, void* _) +{ + close((int)fd); +} + +#if FDBLOCK + +static void +fd_async(void *async_data) +{ + int res; + ErtsSysDriverData *dd = (ErtsSysDriverData *)async_data; + SysIOVec *iov0; + SysIOVec *iov; + int iovlen; + int err = 0; + /* much of this code is stolen from efile_drv:invoke_writev */ + driver_pdl_lock(dd->blocking->pdl); + iov0 = driver_peekq(dd->port_num, &iovlen); + iovlen = iovlen < MAXIOV ? iovlen : MAXIOV; + iov = erts_alloc_fnf(ERTS_ALC_T_SYS_WRITE_BUF, + sizeof(SysIOVec)*iovlen); + if (!iov) { + res = -1; + err = ENOMEM; + driver_pdl_unlock(dd->blocking->pdl); + } else { + memcpy(iov,iov0,iovlen*sizeof(SysIOVec)); + driver_pdl_unlock(dd->blocking->pdl); + + do { + res = writev(dd->ofd->fd, iov, iovlen); + } while (res < 0 && errno == EINTR); + if (res < 0) + err = errno; + err = errno; + + erts_free(ERTS_ALC_T_SYS_WRITE_BUF, iov); + } + dd->blocking->res = res; + dd->blocking->err = err; +} + +void fd_ready_async(ErlDrvData drv_data, + ErlDrvThreadData thread_data) { + ErtsSysDriverData *dd = (ErtsSysDriverData *)thread_data; + ErlDrvPort port_num = dd->port_num; + + ASSERT(dd->blocking); + + if (dd->blocking->res > 0) { + driver_pdl_lock(dd->blocking->pdl); + if (driver_deq(port_num, dd->blocking->res) == 0) { + driver_pdl_unlock(dd->blocking->pdl); + set_busy_port(port_num, 0); + if (dd->terminating) { + /* The port is has been ordered to terminate + from either fd_flush or port_inp_failure */ + if (dd->terminating == 1) + driver_failure_atom(port_num, "normal"); + else if (dd->terminating == 2) + driver_failure_eof(port_num); + else if (dd->terminating < 0) + driver_failure_posix(port_num, -dd->terminating); + return; /* -1; */ + } + } else { + driver_pdl_unlock(dd->blocking->pdl); + /* still data left to write in queue */ + driver_async(port_num, &dd->blocking->pkey, fd_async, dd, NULL); + return /* 0; */; + } + } else if (dd->blocking->res < 0) { + if (dd->blocking->err == ERRNO_BLOCK) { + set_busy_port(port_num, 1); + /* still data left to write in queue */ + driver_async(port_num, &dd->blocking->pkey, fd_async, dd, NULL); + } else + driver_failure_posix(port_num, dd->blocking->err); + return; /* -1; */ + } + return; /* 0; */ +} + +#endif + +/* Forker driver */ + +static int forker_fd; + +static ErlDrvData forker_start(ErlDrvPort port_num, char* name, + SysDriverOpts* opts) +{ + + int i; + int fds[2]; + int res, unbind; + char bindir[MAXPATHLEN]; + size_t bindirsz = sizeof(bindir); + Uint csp_path_sz; + char *child_setup_prog; + + forker_port = erts_drvport2id(port_num); + + res = erts_sys_getenv_raw("BINDIR", bindir, &bindirsz); + if (res != 0) { + if (res < 0) + erts_exit(1, + "Environment variable BINDIR is not set\n"); + if (res > 0) + erts_exit(1, + "Value of environment variable BINDIR is too large\n"); + } + if (bindir[0] != DIR_SEPARATOR_CHAR) + erts_exit(1, + "Environment variable BINDIR does not contain an" + " absolute path\n"); + csp_path_sz = (strlen(bindir) + + 1 /* DIR_SEPARATOR_CHAR */ + + sizeof(CHILD_SETUP_PROG_NAME) + + 1); + child_setup_prog = erts_alloc(ERTS_ALC_T_CS_PROG_PATH, csp_path_sz); + erts_snprintf(child_setup_prog, csp_path_sz, + "%s%c%s", + bindir, + DIR_SEPARATOR_CHAR, + CHILD_SETUP_PROG_NAME); + if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) { + erts_exit(ERTS_ABORT_EXIT, + "Could not open unix domain socket in spawn_init: %d\n", + errno); + } + + forker_fd = fds[0]; + + unbind = erts_sched_bind_atfork_prepare(); + + i = fork(); + + if (i == 0) { + /* The child */ + char *cs_argv[FORKER_ARGV_NO_OF_ARGS] = + {CHILD_SETUP_PROG_NAME, NULL, NULL}; + char buff[128]; + + erts_sched_bind_atfork_child(unbind); + + snprintf(buff, 128, "%d", sys_max_files()); + cs_argv[FORKER_ARGV_MAX_FILES] = buff; + + /* We preallocate fd 3 for the uds fd */ + if (fds[1] != 3) { + dup2(fds[1], 3); + } + +#if defined(USE_SETPGRP_NOARGS) /* SysV */ + (void) setpgrp(); +#elif defined(USE_SETPGRP) /* BSD */ + (void) setpgrp(0, getpid()); +#else /* POSIX */ + (void) setsid(); +#endif + + execv(child_setup_prog, cs_argv); + _exit(1); + } + + erts_sched_bind_atfork_parent(unbind); + + erts_free(ERTS_ALC_T_CS_PROG_PATH, child_setup_prog); + + close(fds[1]); + + SET_NONBLOCKING(forker_fd); + + driver_select(port_num, forker_fd, ERL_DRV_READ|ERL_DRV_USE, 1); + + return (ErlDrvData)port_num; +} + +static void forker_stop(ErlDrvData e) +{ + /* we probably should do something here, + the port has been closed by the user. */ +} + +static void forker_ready_input(ErlDrvData e, ErlDrvEvent fd) +{ + int res; + ErtsSysForkerProto *proto; + + proto = erts_alloc(ERTS_ALC_T_DRV_CTRL_DATA, sizeof(*proto)); + + if ((res = read(fd, proto, sizeof(*proto))) < 0) { + if (errno == ERRNO_BLOCK) + return; + erts_exit(ERTS_DUMP_EXIT, "Failed to read from erl_child_setup: %d\n", errno); + } + + if (res == 0) + erts_exit(ERTS_DUMP_EXIT, "erl_child_setup closed\n"); + + ASSERT(res == sizeof(*proto)); + +#ifdef FORKER_PROTO_START_ACK + if (proto->action == ErtsSysForkerProtoAction_StartAck) { + /* Ideally we would like to not have to ack each Start + command being sent over the uds, but it would seem + that some operating systems (only observed on FreeBSD) + throw away data on the uds when the socket becomes full, + so we have to. + */ + ErlDrvPort port_num = (ErlDrvPort)e; + int vlen; + SysIOVec *iov = driver_peekq(port_num, &vlen); + ErtsSysForkerProto *proto = (ErtsSysForkerProto *)iov[0].iov_base; + + close(proto->u.start.fds[0]); + close(proto->u.start.fds[1]); + if (proto->u.start.fds[1] != proto->u.start.fds[2]) + close(proto->u.start.fds[2]); + + driver_deq(port_num, sizeof(*proto)); + + if (driver_sizeq(port_num) > 0) + driver_select(port_num, forker_fd, ERL_DRV_WRITE|ERL_DRV_USE, 1); + } else +#endif + { + ASSERT(proto->action == ErtsSysForkerProtoAction_SigChld); + + /* ideally this would be a port_command call, but as command is + already used by the spawn_driver, we use control instead. + Note that when using erl_drv_port_control it is an asynchronous + control. */ + erl_drv_port_control(proto->u.sigchld.port_id, 'S', + (char*)proto, sizeof(*proto)); + } + +} + +static void forker_ready_output(ErlDrvData e, ErlDrvEvent fd) +{ + ErlDrvPort port_num = (ErlDrvPort)e; + +#ifndef FORKER_PROTO_START_ACK + while (driver_sizeq(port_num) > 0) { +#endif + int vlen; + SysIOVec *iov = driver_peekq(port_num, &vlen); + ErtsSysForkerProto *proto = (ErtsSysForkerProto *)iov[0].iov_base; + ASSERT(iov[0].iov_len >= (sizeof(*proto))); + if (sys_uds_write(forker_fd, (char*)proto, sizeof(*proto), + proto->u.start.fds, 3, 0) < 0) { + if (errno == ERRNO_BLOCK) + return; + erts_exit(ERTS_DUMP_EXIT, "Failed to write to erl_child_setup: %d\n", errno); + } +#ifndef FORKER_PROTO_START_ACK + close(proto->u.start.fds[0]); + close(proto->u.start.fds[1]); + if (proto->u.start.fds[1] != proto->u.start.fds[2]) + close(proto->u.start.fds[2]); + driver_deq(port_num, sizeof(*proto)); + } +#endif + + driver_select(port_num, forker_fd, ERL_DRV_WRITE, 0); +} + +static ErlDrvSSizeT forker_control(ErlDrvData e, unsigned int cmd, char *buf, + ErlDrvSizeT len, char **rbuf, ErlDrvSizeT rlen) +{ + ErtsSysForkerProto *proto = (ErtsSysForkerProto *)buf; + ErlDrvPort port_num = (ErlDrvPort)e; + int res; + + driver_enq(port_num, buf, len); + if (driver_sizeq(port_num) > sizeof(*proto)) { + return 0; + } + + if ((res = sys_uds_write(forker_fd, (char*)proto, sizeof(*proto), + proto->u.start.fds, 3, 0)) < 0) { + if (errno == ERRNO_BLOCK) { + driver_select(port_num, forker_fd, ERL_DRV_WRITE|ERL_DRV_USE, 1); + return 0; + } + erts_exit(ERTS_DUMP_EXIT, "Failed to write to erl_child_setup: %d\n", errno); + } + +#ifndef FORKER_PROTO_START_ACK + ASSERT(res == sizeof(*proto)); + close(proto->u.start.fds[0]); + close(proto->u.start.fds[1]); + if (proto->u.start.fds[1] != proto->u.start.fds[2]) + close(proto->u.start.fds[2]); + driver_deq(port_num, sizeof(*proto)); +#endif + + return 0; +} |