syscall.c

   1 /*
   2    Copyright (C) Andrew Tridgell 1998
   3    Copyright (C) 2002 by Martin Pool
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20 /**
  21  * @file syscall.c
  22  *
  23  * Syscall wrappers to ensure that nothing gets done in dry_run mode
  24  * and to handle system peculiarities.
  25  **/
  26
  27 #include "rsync.h"
  28
  29 #if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
  30 #include <sys/un.h>
  31 #endif
  32
  33 extern int dry_run;
  34 extern int read_only;
  35 extern int list_only;
  36 extern int preserve_perms;
  37
  38 #define RETURN_ERROR_IF(x,e) \
  39         do { \
  40                 if (x) { \
  41                         errno = (e); \
  42                         return -1; \
  43                 } \
  44         } while (0)
  45
  46 #define RETURN_ERROR_IF_RO_OR_LO RETURN_ERROR_IF(read_only || list_only, EROFS)
  47
  48 int do_unlink(char *fname)
  49 {
  50         if (dry_run) return 0;
  51         RETURN_ERROR_IF_RO_OR_LO;
  52         return unlink(fname);
  53 }
  54
  55 int do_symlink(char *fname1, char *fname2)
  56 {
  57         if (dry_run) return 0;
  58         RETURN_ERROR_IF_RO_OR_LO;
  59         return symlink(fname1, fname2);
  60 }
  61
  62 #ifdef HAVE_LINK
  63 int do_link(char *fname1, char *fname2)
  64 {
  65         if (dry_run) return 0;
  66         RETURN_ERROR_IF_RO_OR_LO;
  67         return link(fname1, fname2);
  68 }
  69 #endif
  70
  71 int do_lchown(const char *path, uid_t owner, gid_t group)
  72 {
  73         if (dry_run) return 0;
  74         RETURN_ERROR_IF_RO_OR_LO;
  75 #ifndef HAVE_LCHOWN
  76 #define lchown chown
  77 #endif
  78         return lchown(path, owner, group);
  79 }
  80
  81 int do_mknod(char *pathname, mode_t mode, dev_t dev)
  82 {
  83         if (dry_run) return 0;
  84         RETURN_ERROR_IF_RO_OR_LO;
  85 #if !defined MKNOD_CREATES_FIFOS && defined HAVE_MKFIFO
  86         if (S_ISFIFO(mode))
  87                 return mkfifo(pathname, mode);
  88 #endif
  89 #if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
  90         if (S_ISSOCK(mode)) {
  91                 int sock;
  92                 struct sockaddr_un saddr;
  93                 unsigned int len;
  94
  95                 saddr.sun_family = AF_UNIX;
  96                 len = strlcpy(saddr.sun_path, pathname, sizeof saddr.sun_path);
  97 #ifdef HAVE_SOCKADDR_UN_LEN
  98                 saddr.sun_len = len >= sizeof saddr.sun_path
  99                               ? sizeof saddr.sun_path : len + 1;
 100 #endif
 101
 102                 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0
 103                     || (unlink(pathname) < 0 && errno != ENOENT)
 104                     || (bind(sock, (struct sockaddr*)&saddr, sizeof saddr)) < 0)
 105                         return -1;
 106                 close(sock);
 107                 return do_chmod(pathname, mode);
 108         }
 109 #endif
 110 #ifdef HAVE_MKNOD
 111         return mknod(pathname, mode, dev);
 112 #else
 113         return -1;
 114 #endif
 115 }
 116
 117 int do_rmdir(char *pathname)
 118 {
 119         if (dry_run) return 0;
 120         RETURN_ERROR_IF_RO_OR_LO;
 121         return rmdir(pathname);
 122 }
 123
 124 int do_open(char *pathname, int flags, mode_t mode)
 125 {
 126         if (flags != O_RDONLY) {
 127                 RETURN_ERROR_IF(dry_run, 0);
 128                 RETURN_ERROR_IF_RO_OR_LO;
 129         }
 130
 131         return open(pathname, flags | O_BINARY, mode);
 132 }
 133
 134 #ifdef HAVE_CHMOD
 135 int do_chmod(const char *path, mode_t mode)
 136 {
 137         int code;
 138         if (dry_run) return 0;
 139         RETURN_ERROR_IF_RO_OR_LO;
 140         code = chmod(path, mode);
 141         if (code != 0 && preserve_perms)
 142             return code;
 143         return 0;
 144 }
 145 #endif
 146
 147 int do_rename(char *fname1, char *fname2)
 148 {
 149         if (dry_run) return 0;
 150         RETURN_ERROR_IF_RO_OR_LO;
 151         return rename(fname1, fname2);
 152 }
 153
 154
 155 void trim_trailing_slashes(char *name)
 156 {
 157         int l;
 158         /* Some BSD systems cannot make a directory if the name
 159          * contains a trailing slash.
 160          * <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */
 161
 162         /* Don't change empty string; and also we can't improve on
 163          * "/" */
 164
 165         l = strlen(name);
 166         while (l > 1) {
 167                 if (name[--l] != '/')
 168                         break;
 169                 name[l] = '\0';
 170         }
 171 }
 172
 173
 174 int do_mkdir(char *fname, mode_t mode)
 175 {
 176         if (dry_run) return 0;
 177         RETURN_ERROR_IF_RO_OR_LO;
 178         trim_trailing_slashes(fname);
 179         return mkdir(fname, mode);
 180 }
 181
 182
 183 /* like mkstemp but forces permissions */
 184 int do_mkstemp(char *template, mode_t perms)
 185 {
 186         RETURN_ERROR_IF(dry_run, 0);
 187         RETURN_ERROR_IF(read_only, EROFS);
 188
 189 #if defined HAVE_SECURE_MKSTEMP && defined HAVE_FCHMOD && (!defined HAVE_OPEN64 || defined HAVE_MKSTEMP64)
 190         {
 191                 int fd = mkstemp(template);
 192                 if (fd == -1)
 193                         return -1;
 194                 if (fchmod(fd, perms) != 0 && preserve_perms) {
 195                         int errno_save = errno;
 196                         close(fd);
 197                         unlink(template);
 198                         errno = errno_save;
 199                         return -1;
 200                 }
 201 #if defined HAVE_SETMODE && O_BINARY
 202                 setmode(fd, O_BINARY);
 203 #endif
 204                 return fd;
 205         }
 206 #else
 207         if (!mktemp(template))
 208                 return -1;
 209         return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms);
 210 #endif
 211 }
 212
 213 int do_stat(const char *fname, STRUCT_STAT *st)
 214 {
 215 #ifdef USE_STAT64_FUNCS
 216         return stat64(fname, st);
 217 #else
 218         return stat(fname, st);
 219 #endif
 220 }
 221
 222 int do_lstat(const char *fname, STRUCT_STAT *st)
 223 {
 224 #ifdef SUPPORT_LINKS
 225 # ifdef USE_STAT64_FUNCS
 226         return lstat64(fname, st);
 227 # else
 228         return lstat(fname, st);
 229 # endif
 230 #else
 231         return do_stat(fname, st);
 232 #endif
 233 }
 234
 235 int do_fstat(int fd, STRUCT_STAT *st)
 236 {
 237 #ifdef USE_STAT64_FUNCS
 238         return fstat64(fd, st);
 239 #else
 240         return fstat(fd, st);
 241 #endif
 242 }
 243
 244 OFF_T do_lseek(int fd, OFF_T offset, int whence)
 245 {
 246 #if SIZEOF_OFF64_T
 247         off64_t lseek64();
 248         return lseek64(fd, offset, whence);
 249 #else
 250         return lseek(fd, offset, whence);
 251 #endif
 252 }
 253
 254 char *d_name(struct dirent *di)
 255 {
 256 #ifdef HAVE_BROKEN_READDIR
 257         return (di->d_name - 2);
 258 #else
 259         return di->d_name;
 260 #endif
 261 }