syscall.c

   1 /*
   2  * Syscall wrappers to ensure that nothing gets done in dry_run mode
   3  * and to handle system peculiarities.
   4  *
   5  * Copyright (C) 1998 Andrew Tridgell
   6  * Copyright (C) 2002 Martin Pool
   7  * Copyright (C) 2003-2007 Wayne Davison
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, visit the http://fsf.org website.
  21  */
  22
  23 #include "rsync.h"
  24
  25 #if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
  26 #include <sys/un.h>
  27 #endif
  28 #ifdef HAVE_SYS_ATTR_H
  29 #include <sys/attr.h>
  30 #endif
  31
  32 extern int dry_run;
  33 extern int am_root;
  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(const 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(const char *fname1, const 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(const char *fname1, const 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(const char *pathname, mode_t mode, dev_t dev)
  82 {
  83         if (dry_run) return 0;
  84         RETURN_ERROR_IF_RO_OR_LO;
  85
  86         /* For --fake-super, we create a normal file with mode 0600. */
  87         if (am_root < 0) {
  88                 int fd = open(pathname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR);
  89                 if (fd < 0 || close(fd) < 0)
  90                         return -1;
  91                 return 0;
  92         }
  93
  94 #if !defined MKNOD_CREATES_FIFOS && defined HAVE_MKFIFO
  95         if (S_ISFIFO(mode))
  96                 return mkfifo(pathname, mode);
  97 #endif
  98 #if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H
  99         if (S_ISSOCK(mode)) {
 100                 int sock;
 101                 struct sockaddr_un saddr;
 102 #ifdef HAVE_SOCKADDR_UN_LEN
 103                 unsigned int len =
 104 #endif
 105                     strlcpy(saddr.sun_path, pathname, sizeof saddr.sun_path);
 106 #ifdef HAVE_SOCKADDR_UN_LEN
 107                 saddr.sun_len = len >= sizeof saddr.sun_path
 108                               ? sizeof saddr.sun_path : len + 1;
 109 #endif
 110                 saddr.sun_family = AF_UNIX;
 111
 112                 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0
 113                     || (unlink(pathname) < 0 && errno != ENOENT)
 114                     || (bind(sock, (struct sockaddr*)&saddr, sizeof saddr)) < 0)
 115                         return -1;
 116                 close(sock);
 117 #ifdef HAVE_CHMOD
 118                 return do_chmod(pathname, mode);
 119 #else
 120                 return 0;
 121 #endif
 122         }
 123 #endif
 124 #ifdef HAVE_MKNOD
 125         return mknod(pathname, mode, dev);
 126 #else
 127         return -1;
 128 #endif
 129 }
 130
 131 int do_rmdir(const char *pathname)
 132 {
 133         if (dry_run) return 0;
 134         RETURN_ERROR_IF_RO_OR_LO;
 135         return rmdir(pathname);
 136 }
 137
 138 int do_open(const char *pathname, int flags, mode_t mode)
 139 {
 140         if (flags != O_RDONLY) {
 141                 RETURN_ERROR_IF(dry_run, 0);
 142                 RETURN_ERROR_IF_RO_OR_LO;
 143         }
 144
 145         return open(pathname, flags | O_BINARY, mode);
 146 }
 147
 148 #ifdef HAVE_CHMOD
 149 int do_chmod(const char *path, mode_t mode)
 150 {
 151         int code;
 152         if (dry_run) return 0;
 153         RETURN_ERROR_IF_RO_OR_LO;
 154         if (S_ISLNK(mode)) {
 155 #ifdef HAVE_LCHMOD
 156                 code = lchmod(path, mode & CHMOD_BITS);
 157 #elif defined HAVE_SETATTRLIST
 158                 struct attrlist attrList;
 159                 uint32_t m = mode & CHMOD_BITS; /* manpage is wrong: not mode_t! */
 160
 161                 memset(&attrList, 0, sizeof attrList);
 162                 attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
 163                 attrList.commonattr = ATTR_CMN_ACCESSMASK;
 164                 code = setattrlist(path, &attrList, &m, sizeof m, FSOPT_NOFOLLOW);
 165 #else
 166                 code = 1;
 167 #endif
 168         } else
 169                 code = chmod(path, mode & CHMOD_BITS);
 170         if (code != 0 && preserve_perms)
 171             return code;
 172         return 0;
 173 }
 174 #endif
 175
 176 int do_rename(const char *fname1, const char *fname2)
 177 {
 178         if (dry_run) return 0;
 179         RETURN_ERROR_IF_RO_OR_LO;
 180         return rename(fname1, fname2);
 181 }
 182
 183 void trim_trailing_slashes(char *name)
 184 {
 185         int l;
 186         /* Some BSD systems cannot make a directory if the name
 187          * contains a trailing slash.
 188          * <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */
 189
 190         /* Don't change empty string; and also we can't improve on
 191          * "/" */
 192
 193         l = strlen(name);
 194         while (l > 1) {
 195                 if (name[--l] != '/')
 196                         break;
 197                 name[l] = '\0';
 198         }
 199 }
 200
 201 int do_mkdir(char *fname, mode_t mode)
 202 {
 203         if (dry_run) return 0;
 204         RETURN_ERROR_IF_RO_OR_LO;
 205         trim_trailing_slashes(fname);
 206         return mkdir(fname, mode);
 207 }
 208
 209 /* like mkstemp but forces permissions */
 210 int do_mkstemp(char *template, mode_t perms)
 211 {
 212         RETURN_ERROR_IF(dry_run, 0);
 213         RETURN_ERROR_IF(read_only, EROFS);
 214         perms |= S_IWUSR;
 215
 216 #if defined HAVE_SECURE_MKSTEMP && defined HAVE_FCHMOD && (!defined HAVE_OPEN64 || defined HAVE_MKSTEMP64)
 217         {
 218                 int fd = mkstemp(template);
 219                 if (fd == -1)
 220                         return -1;
 221                 if (fchmod(fd, perms) != 0 && preserve_perms) {
 222                         int errno_save = errno;
 223                         close(fd);
 224                         unlink(template);
 225                         errno = errno_save;
 226                         return -1;
 227                 }
 228 #if defined HAVE_SETMODE && O_BINARY
 229                 setmode(fd, O_BINARY);
 230 #endif
 231                 return fd;
 232         }
 233 #else
 234         if (!mktemp(template))
 235                 return -1;
 236         return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms);
 237 #endif
 238 }
 239
 240 int do_stat(const char *fname, STRUCT_STAT *st)
 241 {
 242 #ifdef USE_STAT64_FUNCS
 243         return stat64(fname, st);
 244 #else
 245         return stat(fname, st);
 246 #endif
 247 }
 248
 249 int do_lstat(const char *fname, STRUCT_STAT *st)
 250 {
 251 #ifdef SUPPORT_LINKS
 252 # ifdef USE_STAT64_FUNCS
 253         return lstat64(fname, st);
 254 # else
 255         return lstat(fname, st);
 256 # endif
 257 #else
 258         return do_stat(fname, st);
 259 #endif
 260 }
 261
 262 int do_fstat(int fd, STRUCT_STAT *st)
 263 {
 264 #ifdef USE_STAT64_FUNCS
 265         return fstat64(fd, st);
 266 #else
 267         return fstat(fd, st);
 268 #endif
 269 }
 270
 271 OFF_T do_lseek(int fd, OFF_T offset, int whence)
 272 {
 273 #ifdef HAVE_LSEEK64
 274 #if !SIZEOF_OFF64_T
 275         OFF_T lseek64();
 276 #else
 277         off64_t lseek64();
 278 #endif
 279         return lseek64(fd, offset, whence);
 280 #else
 281         return lseek(fd, offset, whence);
 282 #endif
 283 }
 284
 285 char *d_name(struct dirent *di)
 286 {
 287 #ifdef HAVE_BROKEN_READDIR
 288         return (di->d_name - 2);
 289 #else
 290         return di->d_name;
 291 #endif
 292 }