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/*
* Syscall wrappers to ensure that nothing gets done in dry_run mode
* and to handle system peculiarities.
*
* Copyright (C) 1998 Andrew Tridgell
* Copyright (C) 2002 Martin Pool
* Copyright (C) 2003-2014 Wayne Davison
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, visit the http://fsf.org website.
*/
#include "rsync.h"
#if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
#include <sys/un.h>
#endif
#ifdef HAVE_SYS_ATTR_H
#include <sys/attr.h>
#endif
#if defined HAVE_SYS_FALLOCATE && !defined HAVE_FALLOCATE
#include <sys/syscall.h>
#endif
extern int dry_run;
extern int am_root;
extern int am_sender;
extern int read_only;
extern int list_only;
extern int preserve_perms;
extern int preserve_executability;
#define RETURN_ERROR_IF(x,e) \
do { \
if (x) { \
errno = (e); \
return -1; \
} \
} while (0)
#define RETURN_ERROR_IF_RO_OR_LO RETURN_ERROR_IF(read_only || list_only, EROFS)
int do_unlink(const char *fname)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
return unlink(fname);
}
#ifdef SUPPORT_LINKS
int do_symlink(const char *lnk, const char *fname)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
#if defined NO_SYMLINK_XATTRS || defined NO_SYMLINK_USER_XATTRS
/* For --fake-super, we create a normal file with mode 0600
* and write the lnk into it. */
if (am_root < 0) {
int ok, len = strlen(lnk);
int fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR);
if (fd < 0)
return -1;
ok = write(fd, lnk, len) == len;
if (close(fd) < 0)
ok = 0;
return ok ? 0 : -1;
}
#endif
return symlink(lnk, fname);
}
#if defined NO_SYMLINK_XATTRS || defined NO_SYMLINK_USER_XATTRS
ssize_t do_readlink(const char *path, char *buf, size_t bufsiz)
{
/* For --fake-super, we read the link from the file. */
if (am_root < 0) {
int fd = do_open_nofollow(path, O_RDONLY);
if (fd >= 0) {
int len = read(fd, buf, bufsiz);
close(fd);
return len;
}
if (errno != ELOOP)
return -1;
/* A real symlink needs to be turned into a fake one on the receiving
* side, so tell the generator that the link has no length. */
if (!am_sender)
return 0;
/* Otherwise fall through and let the sender report the real length. */
}
return readlink(path, buf, bufsiz);
}
#endif
#endif
#ifdef HAVE_LINK
int do_link(const char *fname1, const char *fname2)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
return link(fname1, fname2);
}
#endif
int do_lchown(const char *path, uid_t owner, gid_t group)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
#ifndef HAVE_LCHOWN
#define lchown chown
#endif
return lchown(path, owner, group);
}
int do_mknod(const char *pathname, mode_t mode, dev_t dev)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
/* For --fake-super, we create a normal file with mode 0600. */
if (am_root < 0) {
int fd = open(pathname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR);
if (fd < 0 || close(fd) < 0)
return -1;
return 0;
}
#if !defined MKNOD_CREATES_FIFOS && defined HAVE_MKFIFO
if (S_ISFIFO(mode))
return mkfifo(pathname, mode);
#endif
#if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
if (S_ISSOCK(mode)) {
int sock;
struct sockaddr_un saddr;
unsigned int len = strlcpy(saddr.sun_path, pathname, sizeof saddr.sun_path);
if (len >= sizeof saddr.sun_path) {
errno = ENAMETOOLONG;
return -1;
}
#ifdef HAVE_SOCKADDR_UN_LEN
saddr.sun_len = len + 1;
#endif
saddr.sun_family = AF_UNIX;
if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0
|| (unlink(pathname) < 0 && errno != ENOENT)
|| (bind(sock, (struct sockaddr*)&saddr, sizeof saddr)) < 0)
return -1;
close(sock);
#ifdef HAVE_CHMOD
return do_chmod(pathname, mode);
#else
return 0;
#endif
}
#endif
#ifdef HAVE_MKNOD
return mknod(pathname, mode, dev);
#else
return -1;
#endif
}
int do_rmdir(const char *pathname)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
return rmdir(pathname);
}
int do_open(const char *pathname, int flags, mode_t mode)
{
if (flags != O_RDONLY) {
RETURN_ERROR_IF(dry_run, 0);
RETURN_ERROR_IF_RO_OR_LO;
}
return open(pathname, flags | O_BINARY, mode);
}
#ifdef HAVE_CHMOD
int do_chmod(const char *path, mode_t mode)
{
int code;
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
#ifdef HAVE_LCHMOD
code = lchmod(path, mode & CHMOD_BITS);
#else
if (S_ISLNK(mode)) {
# if defined HAVE_SETATTRLIST
struct attrlist attrList;
uint32_t m = mode & CHMOD_BITS; /* manpage is wrong: not mode_t! */
memset(&attrList, 0, sizeof attrList);
attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
attrList.commonattr = ATTR_CMN_ACCESSMASK;
code = setattrlist(path, &attrList, &m, sizeof m, FSOPT_NOFOLLOW);
# else
code = 1;
# endif
} else {
#if 0
/* NB - Android 8.0 Oreo gives "Bad system call" and terminates the
* process for any call to chmod(), but fchmod() is alright */
code = chmod(path, mode & CHMOD_BITS); /* DISCOURAGED FUNCTION */
#else
int fd = open(path, O_RDONLY);
if (fd < 0) {
code = fd;
} else {
code = fchmod(fd, mode & CHMOD_BITS);
close(fd);
}
#endif
}
#endif /* !HAVE_LCHMOD */
if (code != 0 && (preserve_perms || preserve_executability))
return code;
return 0;
}
#endif
int do_rename(const char *fname1, const char *fname2)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
return rename(fname1, fname2);
}
#ifdef HAVE_FTRUNCATE
int do_ftruncate(int fd, OFF_T size)
{
int ret;
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
do {
ret = ftruncate(fd, size);
} while (ret < 0 && errno == EINTR);
return ret;
}
#endif
void trim_trailing_slashes(char *name)
{
int l;
/* Some BSD systems cannot make a directory if the name
* contains a trailing slash.
* <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */
/* Don't change empty string; and also we can't improve on
* "/" */
l = strlen(name);
while (l > 1) {
if (name[--l] != '/')
break;
name[l] = '\0';
}
}
int do_mkdir(char *fname, mode_t mode)
{
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
trim_trailing_slashes(fname);
return mkdir(fname, mode);
}
/* like mkstemp but forces permissions */
int do_mkstemp(char *template, mode_t perms)
{
RETURN_ERROR_IF(dry_run, 0);
RETURN_ERROR_IF(read_only, EROFS);
perms |= S_IWUSR;
#if defined HAVE_SECURE_MKSTEMP && defined HAVE_FCHMOD && (!defined HAVE_OPEN64 || defined HAVE_MKSTEMP64)
{
int fd = mkstemp(template);
if (fd == -1)
return -1;
if (fchmod(fd, perms) != 0 && preserve_perms) {
int errno_save = errno;
close(fd);
unlink(template);
errno = errno_save;
return -1;
}
#if defined HAVE_SETMODE && O_BINARY
setmode(fd, O_BINARY);
#endif
return fd;
}
#else
if (!mktemp(template))
return -1;
return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms);
#endif
}
int do_stat(const char *fname, STRUCT_STAT *st)
{
#ifdef USE_STAT64_FUNCS
return stat64(fname, st);
#else
return stat(fname, st);
#endif
}
int do_lstat(const char *fname, STRUCT_STAT *st)
{
#ifdef SUPPORT_LINKS
# ifdef USE_STAT64_FUNCS
return lstat64(fname, st);
# else
return lstat(fname, st);
# endif
#else
return do_stat(fname, st);
#endif
}
int do_fstat(int fd, STRUCT_STAT *st)
{
#ifdef USE_STAT64_FUNCS
return fstat64(fd, st);
#else
return fstat(fd, st);
#endif
}
OFF_T do_lseek(int fd, OFF_T offset, int whence)
{
#ifdef HAVE_LSEEK64
#if !SIZEOF_OFF64_T
OFF_T lseek64();
#else
off64_t lseek64();
#endif
return lseek64(fd, offset, whence);
#else
return lseek(fd, offset, whence);
#endif
}
#ifdef HAVE_UTIMENSAT
int do_utimensat(const char *fname, time_t modtime, uint32 mod_nsec)
{
struct timespec t[2];
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_NOW;
t[1].tv_sec = modtime;
t[1].tv_nsec = mod_nsec;
return utimensat(AT_FDCWD, fname, t, AT_SYMLINK_NOFOLLOW);
}
#endif
#ifdef HAVE_LUTIMES
int do_lutimes(const char *fname, time_t modtime, uint32 mod_nsec)
{
struct timeval t[2];
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
t[0].tv_sec = time(NULL);
t[0].tv_usec = 0;
t[1].tv_sec = modtime;
t[1].tv_usec = mod_nsec / 1000;
return lutimes(fname, t);
}
#endif
#ifdef HAVE_UTIMES
int do_utimes(const char *fname, time_t modtime, uint32 mod_nsec)
{
struct timeval t[2];
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
t[0].tv_sec = time(NULL);
t[0].tv_usec = 0;
t[1].tv_sec = modtime;
t[1].tv_usec = mod_nsec / 1000;
return utimes(fname, t);
}
#elif defined HAVE_UTIME
int do_utime(const char *fname, time_t modtime, UNUSED(uint32 mod_nsec))
{
#ifdef HAVE_STRUCT_UTIMBUF
struct utimbuf tbuf;
#else
time_t t[2];
#endif
if (dry_run) return 0;
RETURN_ERROR_IF_RO_OR_LO;
# ifdef HAVE_STRUCT_UTIMBUF
tbuf.actime = time(NULL);
tbuf.modtime = modtime;
return utime(fname, &tbuf);
# else
t[0] = time(NULL);
t[1] = modtime;
return utime(fname, t);
# endif
}
#else
#error Need utimes or utime function.
#endif
#ifdef SUPPORT_PREALLOCATION
int do_fallocate(int fd, OFF_T offset, OFF_T length)
{
#ifdef FALLOC_FL_KEEP_SIZE
#define DO_FALLOC_OPTIONS FALLOC_FL_KEEP_SIZE
#else
#define DO_FALLOC_OPTIONS 0
#endif
RETURN_ERROR_IF(dry_run, 0);
RETURN_ERROR_IF_RO_OR_LO;
#if defined HAVE_FALLOCATE
return fallocate(fd, DO_FALLOC_OPTIONS, offset, length);
#elif defined HAVE_SYS_FALLOCATE
return syscall(SYS_fallocate, fd, DO_FALLOC_OPTIONS, (loff_t)offset, (loff_t)length);
#elif defined HAVE_EFFICIENT_POSIX_FALLOCATE
return posix_fallocate(fd, offset, length);
#else
#error Coding error in SUPPORT_PREALLOCATION logic.
#endif
}
#endif
int do_open_nofollow(const char *pathname, int flags)
{
#ifndef O_NOFOLLOW
STRUCT_STAT f_st, l_st;
#endif
int fd;
if (flags != O_RDONLY) {
RETURN_ERROR_IF(dry_run, 0);
RETURN_ERROR_IF_RO_OR_LO;
#ifndef O_NOFOLLOW
/* This function doesn't support write attempts w/o O_NOFOLLOW. */
errno = EINVAL;
return -1;
#endif
}
#ifdef O_NOFOLLOW
fd = open(pathname, flags|O_NOFOLLOW);
#else
if (do_lstat(pathname, &l_st) < 0)
return -1;
if (S_ISLNK(l_st.st_mode)) {
errno = ELOOP;
return -1;
}
if ((fd = open(pathname, flags)) < 0)
return fd;
if (do_fstat(fd, &f_st) < 0) {
close_and_return_error:
{
int save_errno = errno;
close(fd);
errno = save_errno;
}
return -1;
}
if (l_st.st_dev != f_st.st_dev || l_st.st_ino != f_st.st_ino) {
errno = EINVAL;
goto close_and_return_error;
}
#endif
return fd;
}