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 extern int dry_run;
  30 extern int read_only;
  31 extern int list_only;
  32 extern int preserve_perms;
  33
  34 #define RETURN_ERROR_IF(x,e) \
  35         do { \
  36                 if (x) { \
  37                         errno = (e); \
  38                         return -1; \
  39                 } \
  40         } while (0)
  41
  42 #define RETURN_ERROR_IF_RO_OR_LO RETURN_ERROR_IF(read_only || list_only, EROFS)
  43
  44 int do_unlink(char *fname)
  45 {
  46         if (dry_run) return 0;
  47         RETURN_ERROR_IF_RO_OR_LO;
  48         return unlink(fname);
  49 }
  50
  51 int do_symlink(char *fname1, char *fname2)
  52 {
  53         if (dry_run) return 0;
  54         RETURN_ERROR_IF_RO_OR_LO;
  55         return symlink(fname1, fname2);
  56 }
  57
  58 #if HAVE_LINK
  59 int do_link(char *fname1, char *fname2)
  60 {
  61         if (dry_run) return 0;
  62         RETURN_ERROR_IF_RO_OR_LO;
  63         return link(fname1, fname2);
  64 }
  65 #endif
  66
  67 int do_lchown(const char *path, uid_t owner, gid_t group)
  68 {
  69         if (dry_run) return 0;
  70         RETURN_ERROR_IF_RO_OR_LO;
  71         return lchown(path, owner, group);
  72 }
  73
  74 #if HAVE_MKNOD
  75 int do_mknod(char *pathname, mode_t mode, dev_t dev)
  76 {
  77         if (dry_run) return 0;
  78         RETURN_ERROR_IF_RO_OR_LO;
  79         return mknod(pathname, mode, dev);
  80 }
  81 #endif
  82
  83 int do_rmdir(char *pathname)
  84 {
  85         if (dry_run) return 0;
  86         RETURN_ERROR_IF_RO_OR_LO;
  87         return rmdir(pathname);
  88 }
  89
  90 int do_open(char *pathname, int flags, mode_t mode)
  91 {
  92         if (flags != O_RDONLY) {
  93                 RETURN_ERROR_IF(dry_run, 0);
  94                 RETURN_ERROR_IF_RO_OR_LO;
  95         }
  96
  97         return open(pathname, flags | O_BINARY, mode);
  98 }
  99
 100 #if HAVE_CHMOD
 101 int do_chmod(const char *path, mode_t mode)
 102 {
 103         int code;
 104         if (dry_run) return 0;
 105         RETURN_ERROR_IF_RO_OR_LO;
 106         code = chmod(path, mode);
 107         if (code != 0 && preserve_perms)
 108             return code;
 109         return 0;
 110 }
 111 #endif
 112
 113 int do_rename(char *fname1, char *fname2)
 114 {
 115         if (dry_run) return 0;
 116         RETURN_ERROR_IF_RO_OR_LO;
 117         return rename(fname1, fname2);
 118 }
 119
 120
 121 void trim_trailing_slashes(char *name)
 122 {
 123         int l;
 124         /* Some BSD systems cannot make a directory if the name
 125          * contains a trailing slash.
 126          * <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */
 127
 128         /* Don't change empty string; and also we can't improve on
 129          * "/" */
 130
 131         l = strlen(name);
 132         while (l > 1) {
 133                 if (name[--l] != '/')
 134                         break;
 135                 name[l] = '\0';
 136         }
 137 }
 138
 139
 140 int do_mkdir(char *fname, mode_t mode)
 141 {
 142         if (dry_run) return 0;
 143         RETURN_ERROR_IF_RO_OR_LO;
 144         trim_trailing_slashes(fname);
 145         return mkdir(fname, mode);
 146 }
 147
 148
 149 /* like mkstemp but forces permissions */
 150 int do_mkstemp(char *template, mode_t perms)
 151 {
 152         RETURN_ERROR_IF(dry_run, 0);
 153         RETURN_ERROR_IF(read_only, EROFS);
 154
 155 #if defined(HAVE_SECURE_MKSTEMP) && defined(HAVE_FCHMOD)
 156         {
 157                 int fd = mkstemp(template);
 158                 if (fd == -1)
 159                         return -1;
 160                 if (fchmod(fd, perms) != 0 && preserve_perms) {
 161                         int errno_save = errno;
 162                         close(fd);
 163                         unlink(template);
 164                         errno = errno_save;
 165                         return -1;
 166                 }
 167                 return fd;
 168         }
 169 #else
 170         if (!mktemp(template))
 171                 return -1;
 172         return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms);
 173 #endif
 174 }
 175
 176 int do_stat(const char *fname, STRUCT_STAT *st)
 177 {
 178 #if HAVE_OFF64_T
 179         return stat64(fname, st);
 180 #else
 181         return stat(fname, st);
 182 #endif
 183 }
 184
 185 #if SUPPORT_LINKS
 186 int do_lstat(const char *fname, STRUCT_STAT *st)
 187 {
 188 #if HAVE_OFF64_T
 189         return lstat64(fname, st);
 190 #else
 191         return lstat(fname, st);
 192 #endif
 193 }
 194 #endif
 195
 196 int do_fstat(int fd, STRUCT_STAT *st)
 197 {
 198 #if HAVE_OFF64_T
 199         return fstat64(fd, st);
 200 #else
 201         return fstat(fd, st);
 202 #endif
 203 }
 204
 205 OFF_T do_lseek(int fd, OFF_T offset, int whence)
 206 {
 207 #if HAVE_OFF64_T
 208         off64_t lseek64();
 209         return lseek64(fd, offset, whence);
 210 #else
 211         return lseek(fd, offset, whence);
 212 #endif
 213 }
 214
 215 #ifdef USE_MMAP
 216 void *do_mmap(void *start, int len, int prot, int flags, int fd, OFF_T offset)
 217 {
 218 #if HAVE_OFF64_T
 219         return mmap64(start, len, prot, flags, fd, offset);
 220 #else
 221         return mmap(start, len, prot, flags, fd, offset);
 222 #endif
 223 }
 224 #endif
 225
 226 char *d_name(struct dirent *di)
 227 {
 228 #if HAVE_BROKEN_READDIR
 229         return (di->d_name - 2);
 230 #else
 231         return di->d_name;
 232 #endif
 233 }