mirror of
http://galexander.org/git/simplesshd.git
synced 2024-10-31 20:40:22 +00:00
342 lines
8.7 KiB
C
342 lines
8.7 KiB
C
|
/*
|
||
|
* Backup handling code.
|
||
|
*
|
||
|
* Copyright (C) 1999 Andrew Tridgell
|
||
|
* 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"
|
||
|
#include "ifuncs.h"
|
||
|
|
||
|
extern int am_root;
|
||
|
extern int preserve_acls;
|
||
|
extern int preserve_xattrs;
|
||
|
extern int preserve_devices;
|
||
|
extern int preserve_specials;
|
||
|
extern int preserve_links;
|
||
|
extern int safe_symlinks;
|
||
|
extern int backup_dir_len;
|
||
|
extern unsigned int backup_dir_remainder;
|
||
|
extern char backup_dir_buf[MAXPATHLEN];
|
||
|
extern char *backup_suffix;
|
||
|
extern char *backup_dir;
|
||
|
|
||
|
/* Returns -1 on error, 0 on missing dir, and 1 on present dir. */
|
||
|
static int validate_backup_dir(void)
|
||
|
{
|
||
|
STRUCT_STAT st;
|
||
|
|
||
|
if (do_lstat(backup_dir_buf, &st) < 0) {
|
||
|
if (errno == ENOENT)
|
||
|
return 0;
|
||
|
rsyserr(FERROR, errno, "backup lstat %s failed", backup_dir_buf);
|
||
|
return -1;
|
||
|
}
|
||
|
if (!S_ISDIR(st.st_mode)) {
|
||
|
int flags = get_del_for_flag(st.st_mode) | DEL_FOR_BACKUP | DEL_RECURSE;
|
||
|
if (delete_item(backup_dir_buf, st.st_mode, flags) == 0)
|
||
|
return 0;
|
||
|
return -1;
|
||
|
}
|
||
|
return 1;
|
||
|
}
|
||
|
|
||
|
/* Create a backup path from the given fname, putting the result into
|
||
|
* backup_dir_buf. Any new directories (compared to the prior backup
|
||
|
* path) are ensured to exist as directories, replacing anything else
|
||
|
* that may be in the way (e.g. a symlink). */
|
||
|
static BOOL copy_valid_path(const char *fname)
|
||
|
{
|
||
|
const char *f;
|
||
|
int val;
|
||
|
BOOL ret = True;
|
||
|
stat_x sx;
|
||
|
char *b, *rel = backup_dir_buf + backup_dir_len, *name = rel;
|
||
|
|
||
|
for (f = fname, b = rel; *f && *f == *b; f++, b++) {
|
||
|
if (*b == '/')
|
||
|
name = b + 1;
|
||
|
}
|
||
|
|
||
|
if (stringjoin(rel, backup_dir_remainder, fname, backup_suffix, NULL) >= backup_dir_remainder) {
|
||
|
rprintf(FERROR, "backup filename too long\n");
|
||
|
*name = '\0';
|
||
|
return False;
|
||
|
}
|
||
|
|
||
|
for ( ; ; name = b + 1) {
|
||
|
if ((b = strchr(name, '/')) == NULL)
|
||
|
return True;
|
||
|
*b = '\0';
|
||
|
|
||
|
val = validate_backup_dir();
|
||
|
if (val == 0)
|
||
|
break;
|
||
|
if (val < 0) {
|
||
|
*name = '\0';
|
||
|
return False;
|
||
|
}
|
||
|
|
||
|
*b = '/';
|
||
|
}
|
||
|
|
||
|
init_stat_x(&sx);
|
||
|
|
||
|
for ( ; b; name = b + 1, b = strchr(name, '/')) {
|
||
|
*b = '\0';
|
||
|
|
||
|
while (do_mkdir(backup_dir_buf, ACCESSPERMS) < 0) {
|
||
|
if (errno == EEXIST) {
|
||
|
val = validate_backup_dir();
|
||
|
if (val > 0)
|
||
|
break;
|
||
|
if (val == 0)
|
||
|
continue;
|
||
|
} else
|
||
|
rsyserr(FERROR, errno, "backup mkdir %s failed", backup_dir_buf);
|
||
|
*name = '\0';
|
||
|
ret = False;
|
||
|
goto cleanup;
|
||
|
}
|
||
|
|
||
|
/* Try to transfer the directory settings of the actual dir
|
||
|
* that the files are coming from. */
|
||
|
if (x_stat(rel, &sx.st, NULL) < 0)
|
||
|
rsyserr(FERROR, errno, "backup stat %s failed", full_fname(rel));
|
||
|
else {
|
||
|
struct file_struct *file;
|
||
|
if (!(file = make_file(rel, NULL, NULL, 0, NO_FILTERS)))
|
||
|
continue;
|
||
|
#ifdef SUPPORT_ACLS
|
||
|
if (preserve_acls && !S_ISLNK(file->mode)) {
|
||
|
get_acl(rel, &sx);
|
||
|
cache_tmp_acl(file, &sx);
|
||
|
free_acl(&sx);
|
||
|
}
|
||
|
#endif
|
||
|
#ifdef SUPPORT_XATTRS
|
||
|
if (preserve_xattrs) {
|
||
|
get_xattr(rel, &sx);
|
||
|
cache_tmp_xattr(file, &sx);
|
||
|
free_xattr(&sx);
|
||
|
}
|
||
|
#endif
|
||
|
set_file_attrs(backup_dir_buf, file, NULL, NULL, 0);
|
||
|
unmake_file(file);
|
||
|
}
|
||
|
|
||
|
*b = '/';
|
||
|
}
|
||
|
|
||
|
cleanup:
|
||
|
|
||
|
#ifdef SUPPORT_ACLS
|
||
|
uncache_tmp_acls();
|
||
|
#endif
|
||
|
#ifdef SUPPORT_XATTRS
|
||
|
uncache_tmp_xattrs();
|
||
|
#endif
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/* Make a complete pathname for backup file and verify any new path elements. */
|
||
|
char *get_backup_name(const char *fname)
|
||
|
{
|
||
|
if (backup_dir) {
|
||
|
/* copy fname into backup_dir_buf while validating the dirs. */
|
||
|
if (copy_valid_path(fname))
|
||
|
return backup_dir_buf;
|
||
|
/* copy_valid_path() has printed an error message. */
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
if (stringjoin(backup_dir_buf, MAXPATHLEN, fname, backup_suffix, NULL) < MAXPATHLEN)
|
||
|
return backup_dir_buf;
|
||
|
|
||
|
rprintf(FERROR, "backup filename too long\n");
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/* Has same return codes as make_backup(). */
|
||
|
static inline int link_or_rename(const char *from, const char *to,
|
||
|
BOOL prefer_rename, STRUCT_STAT *stp)
|
||
|
{
|
||
|
#ifdef SUPPORT_HARD_LINKS
|
||
|
if (!prefer_rename) {
|
||
|
#ifndef CAN_HARDLINK_SYMLINK
|
||
|
if (S_ISLNK(stp->st_mode))
|
||
|
return 0; /* Use copy code. */
|
||
|
#endif
|
||
|
#ifndef CAN_HARDLINK_SPECIAL
|
||
|
if (IS_SPECIAL(stp->st_mode) || IS_DEVICE(stp->st_mode))
|
||
|
return 0; /* Use copy code. */
|
||
|
#endif
|
||
|
if (do_link(from, to) == 0) {
|
||
|
if (DEBUG_GTE(BACKUP, 1))
|
||
|
rprintf(FINFO, "make_backup: HLINK %s successful.\n", from);
|
||
|
return 2;
|
||
|
}
|
||
|
/* We prefer to rename a regular file rather than copy it. */
|
||
|
if (!S_ISREG(stp->st_mode) || errno == EEXIST || errno == EISDIR)
|
||
|
return 0;
|
||
|
}
|
||
|
#endif
|
||
|
if (do_rename(from, to) == 0) {
|
||
|
if (stp->st_nlink > 1 && !S_ISDIR(stp->st_mode)) {
|
||
|
/* If someone has hard-linked the file into the backup
|
||
|
* dir, rename() might return success but do nothing! */
|
||
|
robust_unlink(from); /* Just in case... */
|
||
|
}
|
||
|
if (DEBUG_GTE(BACKUP, 1))
|
||
|
rprintf(FINFO, "make_backup: RENAME %s successful.\n", from);
|
||
|
return 1;
|
||
|
}
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* Hard-link, rename, or copy an item to the backup name. Returns 2 if item
|
||
|
* was duplicated into backup area, 1 if item was moved, or 0 for failure.*/
|
||
|
int make_backup(const char *fname, BOOL prefer_rename)
|
||
|
{
|
||
|
stat_x sx;
|
||
|
struct file_struct *file;
|
||
|
int save_preserve_xattrs;
|
||
|
char *buf = get_backup_name(fname);
|
||
|
int ret = 0;
|
||
|
|
||
|
if (!buf)
|
||
|
return 0;
|
||
|
|
||
|
init_stat_x(&sx);
|
||
|
/* Return success if no file to keep. */
|
||
|
if (x_lstat(fname, &sx.st, NULL) < 0)
|
||
|
return 1;
|
||
|
|
||
|
/* Try a hard-link or a rename first. Using rename is not atomic, but
|
||
|
* is more efficient than forcing a copy for larger files when no hard-
|
||
|
* linking is possible. */
|
||
|
if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
|
||
|
goto success;
|
||
|
if (errno == EEXIST || errno == EISDIR) {
|
||
|
STRUCT_STAT bakst;
|
||
|
if (do_lstat(buf, &bakst) == 0) {
|
||
|
int flags = get_del_for_flag(bakst.st_mode) | DEL_FOR_BACKUP | DEL_RECURSE;
|
||
|
if (delete_item(buf, bakst.st_mode, flags) != 0)
|
||
|
return 0;
|
||
|
}
|
||
|
if ((ret = link_or_rename(fname, buf, prefer_rename, &sx.st)) != 0)
|
||
|
goto success;
|
||
|
}
|
||
|
|
||
|
/* Fall back to making a copy. */
|
||
|
if (!(file = make_file(fname, NULL, &sx.st, 0, NO_FILTERS)))
|
||
|
return 1; /* the file could have disappeared */
|
||
|
|
||
|
#ifdef SUPPORT_ACLS
|
||
|
if (preserve_acls && !S_ISLNK(file->mode)) {
|
||
|
get_acl(fname, &sx);
|
||
|
cache_tmp_acl(file, &sx);
|
||
|
free_acl(&sx);
|
||
|
}
|
||
|
#endif
|
||
|
#ifdef SUPPORT_XATTRS
|
||
|
if (preserve_xattrs) {
|
||
|
get_xattr(fname, &sx);
|
||
|
cache_tmp_xattr(file, &sx);
|
||
|
free_xattr(&sx);
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
/* Check to see if this is a device file, or link */
|
||
|
if ((am_root && preserve_devices && IS_DEVICE(file->mode))
|
||
|
|| (preserve_specials && IS_SPECIAL(file->mode))) {
|
||
|
if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0)
|
||
|
rsyserr(FERROR, errno, "mknod %s failed", full_fname(buf));
|
||
|
else if (DEBUG_GTE(BACKUP, 1))
|
||
|
rprintf(FINFO, "make_backup: DEVICE %s successful.\n", fname);
|
||
|
ret = 2;
|
||
|
}
|
||
|
|
||
|
#ifdef SUPPORT_LINKS
|
||
|
if (!ret && preserve_links && S_ISLNK(file->mode)) {
|
||
|
const char *sl = F_SYMLINK(file);
|
||
|
if (safe_symlinks && unsafe_symlink(sl, fname)) {
|
||
|
if (INFO_GTE(SYMSAFE, 1)) {
|
||
|
rprintf(FINFO, "not backing up unsafe symlink \"%s\" -> \"%s\"\n",
|
||
|
fname, sl);
|
||
|
}
|
||
|
ret = 2;
|
||
|
} else {
|
||
|
if (do_symlink(sl, buf) < 0)
|
||
|
rsyserr(FERROR, errno, "link %s -> \"%s\"", full_fname(buf), sl);
|
||
|
else if (DEBUG_GTE(BACKUP, 1))
|
||
|
rprintf(FINFO, "make_backup: SYMLINK %s successful.\n", fname);
|
||
|
ret = 2;
|
||
|
}
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
if (!ret && !S_ISREG(file->mode)) {
|
||
|
rprintf(FINFO, "make_bak: skipping non-regular file %s\n", fname);
|
||
|
unmake_file(file);
|
||
|
#ifdef SUPPORT_ACLS
|
||
|
uncache_tmp_acls();
|
||
|
#endif
|
||
|
#ifdef SUPPORT_XATTRS
|
||
|
uncache_tmp_xattrs();
|
||
|
#endif
|
||
|
return 2;
|
||
|
}
|
||
|
|
||
|
/* Copy to backup tree if a file. */
|
||
|
if (!ret) {
|
||
|
if (copy_file(fname, buf, -1, file->mode) < 0) {
|
||
|
rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
|
||
|
full_fname(fname), buf);
|
||
|
unmake_file(file);
|
||
|
#ifdef SUPPORT_ACLS
|
||
|
uncache_tmp_acls();
|
||
|
#endif
|
||
|
#ifdef SUPPORT_XATTRS
|
||
|
uncache_tmp_xattrs();
|
||
|
#endif
|
||
|
return 0;
|
||
|
}
|
||
|
if (DEBUG_GTE(BACKUP, 1))
|
||
|
rprintf(FINFO, "make_backup: COPY %s successful.\n", fname);
|
||
|
ret = 2;
|
||
|
}
|
||
|
|
||
|
save_preserve_xattrs = preserve_xattrs;
|
||
|
preserve_xattrs = 0;
|
||
|
set_file_attrs(buf, file, NULL, fname, 0);
|
||
|
preserve_xattrs = save_preserve_xattrs;
|
||
|
|
||
|
unmake_file(file);
|
||
|
#ifdef SUPPORT_ACLS
|
||
|
uncache_tmp_acls();
|
||
|
#endif
|
||
|
#ifdef SUPPORT_XATTRS
|
||
|
uncache_tmp_xattrs();
|
||
|
#endif
|
||
|
|
||
|
success:
|
||
|
if (INFO_GTE(BACKUP, 1))
|
||
|
rprintf(FINFO, "backed up %s to %s\n", fname, buf);
|
||
|
return ret;
|
||
|
}
|