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