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         /* some systems can't handle a double / */
  89         if (pathname[0] == '/' && pathname[1] == '/') pathname++;
  90
  91         return open(pathname, flags | O_BINARY, mode);
  92 }
  93
  94 #if HAVE_CHMOD
  95 int do_chmod(const char *path, mode_t mode)
  96 {
  97         int code;
  98         if (dry_run) return 0;
  99         CHECK_RO
 100         code = chmod(path, mode);
 101         if ((code != 0) && preserve_perms)
 102             return code;
 103         return 0;
 104 }
 105 #endif
 106
 107 int do_rename(char *fname1, char *fname2)
 108 {
 109         if (dry_run) return 0;
 110         CHECK_RO
 111         return rename(fname1, fname2);
 112 }
 113
 114
 115 void trim_trailing_slashes(char *name)
 116 {
 117         int l;
 118         /* Some BSD systems cannot make a directory if the name
 119          * contains a trailing slash.
 120          * <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */
 121
 122         /* Don't change empty string; and also we can't improve on
 123          * "/" */
 124
 125         l = strlen(name);
 126         while (l > 1) {
 127                 if (name[--l] != '/')
 128                         break;
 129                 name[l] = '\0';
 130         }
 131 }
 132
 133
 134 int do_mkdir(char *fname, mode_t mode)
 135 {
 136         if (dry_run)
 137                 return 0;
 138         CHECK_RO;
 139         trim_trailing_slashes(fname);
 140         return mkdir(fname, mode);
 141 }
 142
 143
 144 /* like mkstemp but forces permissions */
 145 int do_mkstemp(char *template, mode_t perms)
 146 {
 147         if (dry_run) return -1;
 148         if (read_only) {errno = EROFS; return -1;}
 149
 150 #if defined(HAVE_SECURE_MKSTEMP) && defined(HAVE_FCHMOD)
 151         {
 152                 int fd = mkstemp(template);
 153                 if (fd == -1) return -1;
 154                 if ((fchmod(fd, perms) != 0) && preserve_perms) {
 155                         close(fd);
 156                         unlink(template);
 157                         return -1;
 158                 }
 159                 return fd;
 160         }
 161 #else
 162         if (!mktemp(template)) return -1;
 163         return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms);
 164 #endif
 165 }
 166
 167 int do_stat(const char *fname, STRUCT_STAT *st)
 168 {
 169 #if HAVE_OFF64_T
 170         return stat64(fname, st);
 171 #else
 172         return stat(fname, st);
 173 #endif
 174 }
 175
 176 #if SUPPORT_LINKS
 177 int do_lstat(const char *fname, STRUCT_STAT *st)
 178 {
 179 #if HAVE_OFF64_T
 180         return lstat64(fname, st);
 181 #else
 182         return lstat(fname, st);
 183 #endif
 184 }
 185 #endif
 186
 187 int do_fstat(int fd, STRUCT_STAT *st)
 188 {
 189 #if HAVE_OFF64_T
 190         return fstat64(fd, st);
 191 #else
 192         return fstat(fd, st);
 193 #endif
 194 }
 195
 196 OFF_T do_lseek(int fd, OFF_T offset, int whence)
 197 {
 198 #if HAVE_OFF64_T
 199         off64_t lseek64();
 200         return lseek64(fd, offset, whence);
 201 #else
 202         return lseek(fd, offset, whence);
 203 #endif
 204 }
 205
 206 #ifdef USE_MMAP
 207 void *do_mmap(void *start, int len, int prot, int flags, int fd, OFF_T offset)
 208 {
 209 #if HAVE_OFF64_T
 210         return mmap64(start, len, prot, flags, fd, offset);
 211 #else
 212         return mmap(start, len, prot, flags, fd, offset);
 213 #endif
 214 }
 215 #endif
 216
 217 char *d_name(struct dirent *di)
 218 {
 219 #if HAVE_BROKEN_READDIR
 220         return (di->d_name - 2);
 221 #else
 222         return di->d_name;
 223 #endif
 224 }