/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1997-2017. 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%
*/
/*
* Purpose: Provides file and directory operations for Unix.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if defined(HAVE_POSIX_FALLOCATE) && !defined(__sun) && !defined(__sun__)
#define _XOPEN_SOURCE 600
#endif
#if !defined(_GNU_SOURCE) && defined(HAVE_LINUX_FALLOC_H)
#define _GNU_SOURCE
#endif
#include "sys.h"
#include "erl_driver.h"
#include "erl_efile.h"
#include <utime.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_UIO_H
#include <sys/types.h>
#include <sys/uio.h>
#if defined(HAVE_SENDFILE) && (defined(__FreeBSD__) || defined(__DragonFly__))
/* Need to define __BSD_VISIBLE in order to expose prototype of sendfile */
#define __BSD_VISIBLE 1
#include <sys/socket.h>
#endif
#endif
#if defined(HAVE_SENDFILE) && (defined(__linux__) || (defined(__sun) && defined(__SVR4)))
#include <sys/sendfile.h>
#endif
#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
#ifdef SUNOS4
# define getcwd(buf, size) getwd(buf)
#endif
/* Find a definition of MAXIOV, that is used in the code later. */
#if defined IOV_MAX
#define MAXIOV IOV_MAX
#elif defined UIO_MAXIOV
#define MAXIOV UIO_MAXIOV
#else
#define MAXIOV 16
#endif
/*
* Macros for testing file types.
*/
#define ISDIR(st) (S_ISDIR((st).st_mode))
#define ISREG(st) (S_ISREG((st).st_mode))
#define ISDEV(st) (S_ISCHR((st).st_mode) || S_ISBLK((st).st_mode))
#define ISLNK(st) (S_ISLNK((st).st_mode))
#ifdef NO_UMASK
#define FILE_MODE 0644
#define DIR_MODE 0755
#else
#define FILE_MODE 0666
#define DIR_MODE 0777
#endif
#define IS_DOT_OR_DOTDOT(s) \
(s[0] == '.' && (s[1] == '\0' || (s[1] == '.' && s[2] == '\0')))
static int check_error(int result, Efile_error* errInfo);
static int
check_error(int result, Efile_error *errInfo)
{
if (result < 0) {
errInfo->posix_errno = errInfo->os_errno = errno;
return 0;
}
return 1;
}
int
efile_init() {
return 1;
}
int
efile_mkdir(Efile_error* errInfo, /* Where to return error codes. */
char* name) /* Name of directory to create. */
{
#ifdef NO_MKDIR_MODE
return check_error(mkdir(name), errInfo);
#else
return check_error(mkdir(name, DIR_MODE), errInfo);
#endif
}
int
efile_rmdir(Efile_error* errInfo, /* Where to return error codes. */
char* name) /* Name of directory to delete. */
{
if (rmdir(name) == 0) {
return 1;
}
if (errno == ENOTEMPTY) {
errno = EEXIST;
}
if (errno == EEXIST) {
int saved_errno = errno;
struct stat file_stat;
struct stat cwd_stat;
/*
* The error code might be wrong if this is the current directory.
*/
if (stat(name, &file_stat) == 0 && stat(".", &cwd_stat) == 0 &&
file_stat.st_ino == cwd_stat.st_ino &&
file_stat.st_dev == cwd_stat.st_dev) {
saved_errno = EINVAL;
}
errno = saved_errno;
}
return check_error(-1, errInfo);
}
int
efile_delete_file(Efile_error* errInfo, /* Where to return error codes. */
char* name) /* Name of file to delete. */
{
if (unlink(name) == 0) {
return 1;
}
if (errno == EISDIR) { /* Linux sets the wrong error code. */
errno = EPERM;
}
return check_error(-1, errInfo);
}
/*
*---------------------------------------------------------------------------
*
* Changes the name of an existing file or directory, from src to dst.
* If src and dst refer to the same file or directory, does nothing
* and returns success. Otherwise if dst already exists, it will be
* deleted and replaced by src subject to the following conditions:
* If src is a directory, dst may be an empty directory.
* If src is a file, dst may be a file.
* In any other situation where dst already exists, the rename will
* fail.
*
* Results:
* If the directory was successfully created, returns 1.
* Otherwise the return value is 0 and errno is set to
* indicate the error. Some possible values for errno are:
*
* EACCES: src or dst parent directory can't be read and/or written.
* EEXIST: dst is a non-empty directory.
* EINVAL: src is a root directory or dst is a subdirectory of src.
* EISDIR: dst is a directory, but src is not.
* ENOENT: src doesn't exist, or src or dst is "".
* ENOTDIR: src is a directory, but dst is not.
* EXDEV: src and dst are on different filesystems.
*
* Side effects:
* 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.
*
*---------------------------------------------------------------------------
*/
int
efile_rename(Efile_error* errInfo, /* Where to return error codes. */
char* src, /* Original name. */
char* dst) /* New name. */
{
if (rename(src, dst) == 0) {
return 1;
}
if (errno == ENOTEMPTY) {
errno = EEXIST;
}
#if defined (sparc)
/*
* SunOS 4.1.4 reports overwriting a non-empty directory with a
* directory as EINVAL instead of EEXIST (first rule out the correct
* EINVAL result code for moving a directory into itself). Must be
* conditionally compiled because realpath() is only defined on SunOS.
*/
if (errno == EINVAL) {
char srcPath[MAXPATHLEN], dstPath[MAXPATHLEN];
DIR *dirPtr;
struct dirent *dirEntPtr;
#ifdef PURIFY
memset(srcPath, '\0', sizeof(srcPath));
memset(dstPath, '\0', sizeof(dstPath));
#endif
if ((realpath(src, srcPath) != NULL)
&& (realpath(dst, dstPath) != NULL)
&& (strncmp(srcPath, dstPath, strlen(srcPath)) != 0)) {
dirPtr = opendir(dst);
if (dirPtr != NULL) {
while ((dirEntPtr = readdir(dirPtr)) != NULL) {
if ((strcmp(dirEntPtr->d_name, ".") != 0) &&
(strcmp(dirEntPtr->d_name, "..") != 0)) {
errno = EEXIST;
closedir(dirPtr);
return check_error(-1, errInfo);
}
}
closedir(dirPtr);
}
}
errno = EINVAL;
}
#endif /* sparc */
if (strcmp(src, "/") == 0) {
/*
* Alpha reports renaming / as EBUSY and Linux reports it as EACCES,
* instead of EINVAL.
*/
errno = EINVAL;
}
/*
* DEC Alpha OSF1 V3.0 returns EACCES when attempting to move a
* file across filesystems and the parent directory of that file is
* not writable. Most other systems return EXDEV. Does nothing to
* correct this behavior.
*/
return check_error(-1, errInfo);
}
int
efile_chdir(Efile_error* errInfo, /* Where to return error codes. */
char* name) /* Name of directory to make current. */
{
return check_error(chdir(name), errInfo);
}
int
efile_getdcwd(Efile_error* errInfo, /* Where to return error codes. */
int drive, /* 0 - current, 1 - A, 2 - B etc. */
char* buffer, /* Where to return the current
directory. */
size_t size) /* Size of buffer. */
{
if (drive == 0) {
if (getcwd(buffer, size) == NULL)
return check_error(-1, errInfo);
#ifdef SIMSPARCSOLARIS
/* We get "host:" prepended to the dirname - remove!. */
{
int i = 0;
int j = 0;
while ((buffer[i] != ':') && (buffer[i] != '\0')) i++;
if (buffer[i] == ':') {
i++;
while ((buffer[j++] = buffer[i++]) != '\0');
}
}
#endif
return 1;
}
/*
* Drives other than 0 is not supported on Unix.
*/
errno = ENOTSUP;
return check_error(-1, errInfo);
}
int
efile_readdir(Efile_error* errInfo, /* Where to return error codes. */
char* name, /* Name of directory to open. */
EFILE_DIR_HANDLE* p_dir_handle, /* Pointer to directory
handle of
open directory.*/
char* buffer, /* Pointer to buffer for
one filename. */
size_t *size) /* in-out Size of buffer, length
of name. */
{
DIR *dp; /* Pointer to directory structure. */
struct dirent* dirp; /* Pointer to directory entry. */
/*
* If this is the first call, we must open the directory.
*/
if (*p_dir_handle == NULL) {
dp = opendir(name);
if (dp == NULL)
return check_error(-1, errInfo);
*p_dir_handle = (EFILE_DIR_HANDLE) dp;
}
/*
* Retrieve the name of the next file using the directory handle.
*/
dp = *((DIR **)((void *)p_dir_handle));
for (;;) {
dirp = readdir(dp);
if (dirp == NULL) {
closedir(dp);
return 0;
}
if (IS_DOT_OR_DOTDOT(dirp->d_name))
continue;
buffer[0] = '\0';
strncat(buffer, dirp->d_name, (*size)-1);
*size = strlen(dirp->d_name);
return 1;
}
}
int
efile_openfile(Efile_error* errInfo, /* Where to return error codes. */
char* name, /* Name of directory to open. */
int flags, /* Flags to user for opening. */
int* pfd, /* Where to store the file
descriptor. */
Sint64 *pSize) /* Where to store the size of the
file. */
{
struct stat statbuf;
int fd;
int mode; /* Open mode. */
switch (flags & (EFILE_MODE_READ|EFILE_MODE_WRITE)) {
case EFILE_MODE_READ:
mode = O_RDONLY;
break;
case EFILE_MODE_WRITE:
if (flags & EFILE_NO_TRUNCATE)
mode = O_WRONLY | O_CREAT;
else
mode = O_WRONLY | O_CREAT | O_TRUNC;
break;
case EFILE_MODE_READ_WRITE:
mode = O_RDWR | O_CREAT;
break;
default:
errno = EINVAL;
return check_error(-1, errInfo);
}
if (flags & EFILE_MODE_APPEND) {
mode &= ~O_TRUNC;
mode |= O_APPEND;
}
if (flags & EFILE_MODE_EXCL) {
mode |= O_EXCL;
}
if (flags & EFILE_MODE_SYNC) {
#ifdef O_SYNC
mode |= O_SYNC;
#else
errno = ENOTSUP;
return check_error(-1, errInfo);
#endif
}
#ifdef HAVE_FSTAT
while (((fd = open(name, mode, FILE_MODE)) < 0) && (errno == EINTR));
if (!check_error(fd, errInfo)) return 0;
#endif
if (
#ifdef HAVE_FSTAT
fstat(fd, &statbuf) < 0
#else
stat(name, &statbuf) < 0
#endif
) {
/* statbuf is undefined: if the caller depends on it,
i.e. invoke_read_file(), fail the call immediately */
if (pSize && flags == EFILE_MODE_READ) {
check_error(-1, errInfo);
#ifdef HAVE_FSTAT
efile_closefile(fd);
#endif
return 0;
}
}
else if (! ISREG(statbuf)) {
struct stat nullstatbuf;
/*
* For UNIX only, here is some ugly code to allow
* /dev/null to be opened as a file.
*/
if ( (stat("/dev/null", &nullstatbuf) < 0)
|| (statbuf.st_ino != nullstatbuf.st_ino)
|| (statbuf.st_dev != nullstatbuf.st_dev) ) {
errno = EISDIR;
return check_error(-1, errInfo);
}
}
#ifndef HAVE_FSTAT
while (((fd = open(name, mode, FILE_MODE)) < 0) && (errno == EINTR));
if (!check_error(fd, errInfo)) return 0;
#endif
*pfd = fd;
if (pSize) *pSize = statbuf.st_size;
return 1;
}
int
efile_may_openfile(Efile_error* errInfo, char *name) {
struct stat statbuf; /* Information about the file */
int result;
result = stat(name, &statbuf);
if (!check_error(result, errInfo))
return 0;
if (!ISREG(statbuf)) {
errno = EISDIR;
return check_error(-1, errInfo);
}
return 1;
}
void
efile_closefile(int fd)
{
while((close(fd) < 0) && (errno == EINTR));
}
int
efile_fdatasync(Efile_error *errInfo, /* Where to return error codes. */
int fd) /* File descriptor for file to sync data. */
{
#if defined(HAVE_FDATASYNC) && !defined(__DARWIN__)
return check_error(fdatasync(fd), errInfo);
#else
return efile_fsync(errInfo, fd);
#endif
}
int
efile_fsync(Efile_error *errInfo, /* Where to return error codes. */
int fd) /* File descriptor for file to sync. */
{
#ifdef NO_FSYNC
undefined fsync /* XXX: Really? */
#else
#if defined(__DARWIN__) && defined(F_FULLFSYNC)
return check_error(fcntl(fd, F_FULLFSYNC), errInfo);
#else
return check_error(fsync(fd), errInfo);
#endif /* __DARWIN__ */
#endif /* NO_FSYNC */
}
int
efile_fileinfo(Efile_error* errInfo, Efile_info* pInfo,
char* name, int info_for_link)
{
struct stat statbuf; /* Information about the file */
int result;
if (info_for_link) {
result = lstat(name, &statbuf);
} else {
result = stat(name, &statbuf);
}
if (!check_error(result, errInfo)) {
return 0;
}
#if SIZEOF_OFF_T == 4
pInfo->size_high = 0;
#else
pInfo->size_high = (Uint32)(statbuf.st_size >> 32);
#endif
pInfo->size_low = (Uint32)statbuf.st_size;
#ifdef NO_ACCESS
/* Just look at read/write access for owner. */
pInfo->access = ((statbuf.st_mode >> 6) & 07) >> 1;
#else
pInfo->access = FA_NONE;
if (access(name, R_OK) == 0)
pInfo->access |= FA_READ;
if (access(name, W_OK) == 0)
pInfo->access |= FA_WRITE;
#endif
if (ISDEV(statbuf))
pInfo->type = FT_DEVICE;
else if (ISDIR(statbuf))
pInfo->type = FT_DIRECTORY;
else if (ISREG(statbuf))
pInfo->type = FT_REGULAR;
else if (ISLNK(statbuf))
pInfo->type = FT_SYMLINK;
else
pInfo->type = FT_OTHER;
pInfo->accessTime = (Sint64)statbuf.st_atime;
pInfo->modifyTime = (Sint64)statbuf.st_mtime;
pInfo->cTime = (Sint64)statbuf.st_ctime;
pInfo->mode = statbuf.st_mode;
pInfo->links = statbuf.st_nlink;
pInfo->major_device = statbuf.st_dev;
pInfo->minor_device = statbuf.st_rdev;
pInfo->inode = statbuf.st_ino;
pInfo->uid = statbuf.st_uid;
pInfo->gid = statbuf.st_gid;
return 1;
}
int
efile_write_info(Efile_error *errInfo, Efile_info *pInfo, char *name)
{
struct utimbuf tval;
/*
* On some systems chown will always fail for a non-root user unless
* POSIX_CHOWN_RESTRICTED is not set. Others will succeed as long as
* you don't try to chown a file to someone besides youself.
*/
if (chown(name, pInfo->uid, pInfo->gid) && errno != EPERM) {
return check_error(-1, errInfo);
}
if (pInfo->mode != -1) {
mode_t newMode = pInfo->mode & (S_ISUID | S_ISGID |
S_IRWXU | S_IRWXG | S_IRWXO);
if (chmod(name, newMode)) {
newMode &= ~(S_ISUID | S_ISGID);
if (chmod(name, newMode)) {
return check_error(-1, errInfo);
}
}
}
tval.actime = (time_t)pInfo->accessTime;
tval.modtime = (time_t)pInfo->modifyTime;
return check_error(utime(name, &tval), errInfo);
}
int
efile_write(Efile_error* errInfo, /* Where to return error codes. */
int flags, /* Flags given when file was
opened. */
int fd, /* File descriptor to write to. */
char* buf, /* Buffer to write. */
size_t count) /* Number of bytes to write. */
{
ssize_t written; /* Bytes written in last operation. */
while (count > 0) {
if ((written = write(fd, buf, count)) < 0) {
if (errno != EINTR)
return check_error(-1, errInfo);
else
written = 0;
}
ASSERT(written <= count);
buf += written;
count -= written;
}
return 1;
}
int
efile_writev(Efile_error* errInfo, /* Where to return error codes */
int flags, /* Flags given when file was
* opened */
int fd, /* File descriptor to write to */
SysIOVec* iov, /* Vector of buffer structs.
* The structs may be changed i.e.
* due to incomplete writes */
int iovcnt) /* Number of structs in vector */
{
int cnt = 0; /* Buffers so far written */
ASSERT(iovcnt >= 0);
while (cnt < iovcnt) {
if ((! iov[cnt].iov_base) || (iov[cnt].iov_len <= 0)) {
/* Empty buffer - skip */
cnt++;
} else { /* Non-empty buffer */
ssize_t w; /* Bytes written in this call */
#ifdef HAVE_WRITEV
int b = iovcnt - cnt; /* Buffers to write */
/* Use as many buffers as MAXIOV allows */
if (b > MAXIOV)
b = MAXIOV;
if (b > 1) {
do {
w = writev(fd, &iov[cnt], b);
} while (w < 0 && errno == EINTR);
if (w < 0 && errno == EINVAL) {
goto single_write;
}
} else
single_write:
/* Degenerated io vector - use regular write */
#endif
{
do {
size_t iov_len = iov[cnt].iov_len;
size_t limit = 1024*1024*1024; /* 1GB */
if (iov_len > limit) {
iov_len = limit;
}
w = write(fd, iov[cnt].iov_base, iov_len);
} while (w < 0 && errno == EINTR);
ASSERT(w <= iov[cnt].iov_len ||
(w == -1 && errno != EINTR));
}
if (w < 0) return check_error(-1, errInfo);
/* Move forward to next buffer to write */
for (; cnt < iovcnt && w > 0; cnt++) {
if (iov[cnt].iov_base && iov[cnt].iov_len > 0) {
if (w < iov[cnt].iov_len) {
/* Adjust the buffer for next write */
iov[cnt].iov_len -= w;
iov[cnt].iov_base = ((char *)iov[cnt].iov_base) + w;
w = 0;
break;
} else {
w -= iov[cnt].iov_len;
}
}
}
ASSERT(w == 0);
} /* else Non-empty buffer */
} /* while (cnt< iovcnt) */
return 1;
}
int
efile_read(Efile_error* errInfo, /* Where to return error codes. */
int flags, /* Flags given when file was opened. */
int fd, /* File descriptor to read from. */
char* buf, /* Buffer to read into. */
size_t count, /* Number of bytes to read. */
size_t *pBytesRead) /* Where to return number of
bytes read. */
{
ssize_t n;
for (;;) {
if ((n = read(fd, buf, count)) >= 0)
break;
else if (errno != EINTR)
return check_error(-1, errInfo);
}
*pBytesRead = (size_t) n;
return 1;
}
/* pread() and pwrite() */
/* Some unix systems, notably Solaris has these syscalls */
/* It is especially nice for i.e. the dets module to have support */
/* for this, even if the underlying OS dosn't support it, it is */
/* reasonably easy to work around by first calling seek, and then */
/* calling read(). */
/* This later strategy however changes the file pointer, which pread() */
/* does not do. We choose to ignore this and say that the location */
/* of the file pointer is undefined after a call to any of the p functions*/
int
efile_pread(Efile_error* errInfo, /* Where to return error codes. */
int fd, /* File descriptor to read from. */
Sint64 offset, /* Offset in bytes from BOF. */
char* buf, /* Buffer to read into. */
size_t count, /* Number of bytes to read. */
size_t *pBytesRead) /* Where to return
number of bytes read. */
{
#if defined(HAVE_PREAD) && defined(HAVE_PWRITE)
ssize_t n;
off_t off = (off_t) offset;
if (off != offset) {
errno = EINVAL;
return check_error(-1, errInfo);
}
for (;;) {
if ((n = pread(fd, buf, count, offset)) >= 0)
break;
else if (errno != EINTR)
return check_error(-1, errInfo);
}
*pBytesRead = (size_t) n;
return 1;
#else
{
int res = efile_seek(errInfo, fd, offset, EFILE_SEEK_SET, NULL);
if (res) {
return efile_read(errInfo, 0, fd, buf, count, pBytesRead);
} else {
return res;
}
}
#endif
}
int
efile_pwrite(Efile_error* errInfo, /* Where to return error codes. */
int fd, /* File descriptor to write to. */
char* buf, /* Buffer to write. */
size_t count, /* Number of bytes to write. */
Sint64 offset) /* where to write it */
{
#if defined(HAVE_PREAD) && defined(HAVE_PWRITE)
ssize_t written; /* Bytes written in last operation. */
off_t off = (off_t) offset;
if (off != offset) {
errno = EINVAL;
return check_error(-1, errInfo);
}
while (count > 0) {
if ((written = pwrite(fd, buf, count, offset)) < 0) {
if (errno != EINTR)
return check_error(-1, errInfo);
else
written = 0;
}
ASSERT(written <= count);
buf += written;
count -= written;
offset += written;
}
return 1;
#else /* For unix systems that don't support pread() and pwrite() */
{
int res = efile_seek(errInfo, fd, offset, EFILE_SEEK_SET, NULL);
if (res) {
return efile_write(errInfo, 0, fd, buf, count);
} else {
return res;
}
}
#endif
}
int
efile_seek(Efile_error* errInfo, /* Where to return error codes. */
int fd, /* File descriptor to do the seek on. */
Sint64 offset, /* Offset in bytes from the given
origin. */
int origin, /* Origin of seek (SEEK_SET, SEEK_CUR,
SEEK_END). */
Sint64 *new_location) /* Resulting new location in file. */
{
off_t off, result;
switch (origin) {
case EFILE_SEEK_SET: origin = SEEK_SET; break;
case EFILE_SEEK_CUR: origin = SEEK_CUR; break;
case EFILE_SEEK_END: origin = SEEK_END; break;
default:
errno = EINVAL;
return check_error(-1, errInfo);
}
off = (off_t) offset;
if (off != offset) {
errno = EINVAL;
return check_error(-1, errInfo);
}
errno = 0;
result = lseek(fd, off, origin);
/*
* Note that 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)
return check_error(-1, errInfo);
if (new_location) {
*new_location = result;
}
return 1;
}
int
efile_truncate_file(Efile_error* errInfo, int *fd, int flags)
{
#ifndef NO_FTRUNCATE
off_t offset;
return check_error((offset = lseek(*fd, 0, 1)) >= 0 &&
ftruncate(*fd, offset) == 0 ? 1 : -1,
errInfo);
#else
return 1;
#endif
}
int
efile_readlink(Efile_error* errInfo, char* name, char* buffer, size_t size)
{
int len;
ASSERT(size > 0);
len = readlink(name, buffer, size-1);
if (len == -1) {
return check_error(-1, errInfo);
}
buffer[len] = '\0';
return 1;
}
int
efile_altname(Efile_error* errInfo, char* name, char* buffer, size_t size)
{
errno = ENOTSUP;
return check_error(-1, errInfo);
}
int
efile_link(Efile_error* errInfo, char* old, char* new)
{
return check_error(link(old, new), errInfo);
}
int
efile_symlink(Efile_error* errInfo, char* old, char* new)
{
return check_error(symlink(old, new), errInfo);
}
int
efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset,
Sint64 length, int advise)
{
#ifdef HAVE_POSIX_FADVISE
return check_error(posix_fadvise(fd, offset, length, advise), errInfo);
#else
return check_error(0, errInfo);
#endif
}
#ifdef HAVE_SENDFILE
/* For some reason the maximum size_t cannot be used as the max size
3GB seems to work on all platforms */
#define SENDFILE_CHUNK_SIZE ((1UL << 30) -1)
/*
* sendfile: The implementation of the sendfile system call varies
* a lot on different *nix platforms so to make the api similar in all
* we have to emulate some things in linux and play with variables on
* bsd/darwin.
*
* All of the calls will split a command which tries to send more than
* SENDFILE_CHUNK_SIZE of data at once.
*
* On platforms where *nbytes of 0 does not mean the entire file, this is
* simulated.
*
* It could be possible to implement header/trailer in sendfile. Though
* you would have to emulate it in linux and on BSD/Darwin some complex
* calculations have to be made when using a non blocking socket to figure
* out how much of the header/file/trailer was sent in each command.
*
* The semantics of the API is this:
* Return value: 1 if all data was sent and the function does not need to
* be called again. 0 if an error occures OR if there is more data which
* has to be sent (EAGAIN or EINTR will be set appropriately)
*
* The amount of data written in a call is returned through nbytes.
*
*/
int
efile_sendfile(Efile_error* errInfo, int in_fd, int out_fd,
off_t *offset, Uint64 *nbytes, struct t_sendfile_hdtl* hdtl)
{
Uint64 written = 0;
#if defined(__linux__)
ssize_t retval;
do {
/* check if *nbytes is 0 or greater than chunk size */
if (*nbytes == 0 || *nbytes > SENDFILE_CHUNK_SIZE)
retval = sendfile(out_fd, in_fd, offset, SENDFILE_CHUNK_SIZE);
else
retval = sendfile(out_fd, in_fd, offset, *nbytes);
if (retval > 0) {
written += retval;
*nbytes -= retval;
}
} while (retval == SENDFILE_CHUNK_SIZE);
if (written != 0) {
/* -1 is not returned by the linux API so we have to simulate it */
retval = -1;
errno = EAGAIN;
}
#elif defined(__sun) && defined(__SVR4) && defined(HAVE_SENDFILEV)
ssize_t retval;
size_t len;
sendfilevec_t fdrec;
fdrec.sfv_fd = in_fd;
fdrec.sfv_flag = 0;
do {
fdrec.sfv_off = *offset;
len = 0;
/* check if *nbytes is 0 or greater than chunk size */
if (*nbytes == 0 || *nbytes > SENDFILE_CHUNK_SIZE)
fdrec.sfv_len = SENDFILE_CHUNK_SIZE;
else
fdrec.sfv_len = *nbytes;
retval = sendfilev(out_fd, &fdrec, 1, &len);
/* Sometimes sendfilev can return -1 and still send data.
When that happens we just pretend that no error happend. */
if (retval != -1 || errno == EAGAIN || errno == EINTR ||
len != 0) {
*offset += len;
*nbytes -= len;
written += len;
if (errno != EAGAIN && errno != EINTR && len != 0)
retval = len;
}
} while (len == SENDFILE_CHUNK_SIZE);
#elif defined(__DARWIN__)
int retval;
off_t len;
do {
/* check if *nbytes is 0 or greater than chunk size */
if(*nbytes > SENDFILE_CHUNK_SIZE)
len = SENDFILE_CHUNK_SIZE;
else
len = *nbytes;
retval = sendfile(in_fd, out_fd, *offset, &len, NULL, 0);
if (retval != -1 || errno == EAGAIN || errno == EINTR) {
*offset += len;
*nbytes -= len;
written += len;
}
} while (len == SENDFILE_CHUNK_SIZE);
#elif defined(__FreeBSD__) || defined(__DragonFly__)
off_t len;
int retval;
do {
if (*nbytes > SENDFILE_CHUNK_SIZE)
retval = sendfile(in_fd, out_fd, *offset, SENDFILE_CHUNK_SIZE,
NULL, &len, 0);
else
retval = sendfile(in_fd, out_fd, *offset, *nbytes, NULL, &len, 0);
if (retval != -1 || errno == EAGAIN || errno == EINTR) {
*offset += len;
*nbytes -= len;
written += len;
}
} while(len == SENDFILE_CHUNK_SIZE);
#endif
*nbytes = written;
return check_error(retval, errInfo);
}
#endif /* HAVE_SENDFILE */
#ifdef HAVE_POSIX_FALLOCATE
static int
call_posix_fallocate(int fd, Sint64 offset, Sint64 length)
{
int ret;
/*
* 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.
*/
do {
ret = posix_fallocate(fd, (off_t) offset, (off_t) length);
if (ret > 0) {
errno = ret;
ret = -1;
}
} while (ret != 0 && errno == EINTR);
return ret;
}
#endif /* HAVE_POSIX_FALLOCATE */
int
efile_fallocate(Efile_error* errInfo, int fd, Sint64 offset, Sint64 length)
{
#if defined HAVE_FALLOCATE
/* Linux specific, more efficient than posix_fallocate. */
int ret;
do {
ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, (off_t) offset, (off_t) length);
} while (ret != 0 && errno == EINTR);
#if defined HAVE_POSIX_FALLOCATE
/* Fallback to posix_fallocate if available. */
if (ret != 0) {
ret = call_posix_fallocate(fd, offset, length);
}
#endif
return check_error(ret, errInfo);
#elif defined F_PREALLOCATE
/* Mac OS X specific, equivalent to posix_fallocate. */
int ret;
fstore_t fs;
memset(&fs, 0, sizeof(fs));
fs.fst_flags = F_ALLOCATECONTIG;
fs.fst_posmode = F_VOLPOSMODE;
fs.fst_offset = (off_t) offset;
fs.fst_length = (off_t) length;
ret = fcntl(fd, F_PREALLOCATE, &fs);
if (-1 == ret) {
fs.fst_flags = F_ALLOCATEALL;
ret = fcntl(fd, F_PREALLOCATE, &fs);
#if defined HAVE_POSIX_FALLOCATE
/* Fallback to posix_fallocate if available. */
if (-1 == ret) {
ret = call_posix_fallocate(fd, offset, length);
}
#endif
}
return check_error(ret, errInfo);
#elif defined HAVE_POSIX_FALLOCATE
/* Other Unixes, use posix_fallocate if available. */
return check_error(call_posix_fallocate(fd, offset, length), errInfo);
#else
errno = ENOTSUP;
return check_error(-1, errInfo);
#endif
}
