archival/libarchive/data_extract_all.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   4  */
   5
   6 #include "libbb.h"
   7 #include "bb_archive.h"
   8
   9 void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
  10 {
  11         file_header_t *file_header = archive_handle->file_header;
  12         int dst_fd;
  13         int res;
  14
  15 #if ENABLE_FEATURE_TAR_SELINUX
  16         char *sctx = archive_handle->tar__sctx[PAX_NEXT_FILE];
  17         if (!sctx)
  18                 sctx = archive_handle->tar__sctx[PAX_GLOBAL];
  19         if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
  20                 setfscreatecon(sctx);
  21                 free(archive_handle->tar__sctx[PAX_NEXT_FILE]);
  22                 archive_handle->tar__sctx[PAX_NEXT_FILE] = NULL;
  23         }
  24 #endif
  25
  26         if (archive_handle->ah_flags & ARCHIVE_CREATE_LEADING_DIRS) {
  27                 char *slash = strrchr(file_header->name, '/');
  28                 if (slash) {
  29                         *slash = '\0';
  30                         bb_make_directory(file_header->name, -1, FILEUTILS_RECUR);
  31                         *slash = '/';
  32                 }
  33         }
  34
  35         if (archive_handle->ah_flags & ARCHIVE_UNLINK_OLD) {
  36                 /* Remove the entry if it exists */
  37                 if (!S_ISDIR(file_header->mode)) {
  38                         /* Is it hardlink?
  39                          * We encode hard links as regular files of size 0 with a symlink */
  40                         if (S_ISREG(file_header->mode)
  41                          && file_header->link_target
  42                          && file_header->size == 0
  43                         ) {
  44                                 /* Ugly special case:
  45                                  * tar cf t.tar hardlink1 hardlink2 hardlink1
  46                                  * results in this tarball structure:
  47                                  * hardlink1
  48                                  * hardlink2 -> hardlink1
  49                                  * hardlink1 -> hardlink1 <== !!!
  50                                  */
  51                                 if (strcmp(file_header->link_target, file_header->name) == 0)
  52                                         goto ret;
  53                         }
  54                         /* Proceed with deleting */
  55                         if (unlink(file_header->name) == -1
  56                          && errno != ENOENT
  57                         ) {
  58                                 bb_perror_msg_and_die("can't remove old file %s",
  59                                                 file_header->name);
  60                         }
  61                 }
  62         }
  63         else if (archive_handle->ah_flags & ARCHIVE_EXTRACT_NEWER) {
  64                 /* Remove the existing entry if its older than the extracted entry */
  65                 struct stat existing_sb;
  66                 if (lstat(file_header->name, &existing_sb) == -1) {
  67                         if (errno != ENOENT) {
  68                                 bb_perror_msg_and_die("can't stat old file");
  69                         }
  70                 }
  71                 else if (existing_sb.st_mtime >= file_header->mtime) {
  72                         if (!(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
  73                          && !S_ISDIR(file_header->mode)
  74                         ) {
  75                                 bb_error_msg("%s not created: newer or "
  76                                         "same age file exists", file_header->name);
  77                         }
  78                         data_skip(archive_handle);
  79                         goto ret;
  80                 }
  81                 else if ((unlink(file_header->name) == -1) && (errno != EISDIR)) {
  82                         bb_perror_msg_and_die("can't remove old file %s",
  83                                         file_header->name);
  84                 }
  85         }
  86
  87         /* Handle hard links separately
  88          * We encode hard links as regular files of size 0 with a symlink */
  89         if (S_ISREG(file_header->mode)
  90          && file_header->link_target
  91          && file_header->size == 0
  92         ) {
  93                 /* hard link */
  94                 res = link(file_header->link_target, file_header->name);
  95                 if ((res == -1) && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
  96                         bb_perror_msg("can't create %slink "
  97                                         "from %s to %s", "hard",
  98                                         file_header->name,
  99                                         file_header->link_target);
 100                 }
 101                 /* Hardlinks have no separate mode/ownership, skip chown/chmod */
 102                 goto ret;
 103         }
 104
 105         /* Create the filesystem entry */
 106         switch (file_header->mode & S_IFMT) {
 107         case S_IFREG: {
 108                 /* Regular file */
 109                 char *dst_name;
 110                 int flags = O_WRONLY | O_CREAT | O_EXCL;
 111                 if (archive_handle->ah_flags & ARCHIVE_O_TRUNC)
 112                         flags = O_WRONLY | O_CREAT | O_TRUNC;
 113                 dst_name = file_header->name;
 114 #ifdef ARCHIVE_REPLACE_VIA_RENAME
 115                 if (archive_handle->ah_flags & ARCHIVE_REPLACE_VIA_RENAME)
 116                         /* rpm-style temp file name */
 117                         dst_name = xasprintf("%s;%x", dst_name, (int)getpid());
 118 #endif
 119                 dst_fd = xopen3(dst_name,
 120                         flags,
 121                         file_header->mode
 122                         );
 123                 bb_copyfd_exact_size(archive_handle->src_fd, dst_fd, file_header->size);
 124                 close(dst_fd);
 125 #ifdef ARCHIVE_REPLACE_VIA_RENAME
 126                 if (archive_handle->ah_flags & ARCHIVE_REPLACE_VIA_RENAME) {
 127                         xrename(dst_name, file_header->name);
 128                         free(dst_name);
 129                 }
 130 #endif
 131                 break;
 132         }
 133         case S_IFDIR:
 134                 res = mkdir(file_header->name, file_header->mode);
 135                 if ((res == -1)
 136                  && (errno != EISDIR) /* btw, Linux doesn't return this */
 137                  && (errno != EEXIST)
 138                  && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
 139                 ) {
 140                         bb_perror_msg("can't make dir %s", file_header->name);
 141                 }
 142                 break;
 143         case S_IFLNK:
 144                 /* Symlink */
 145 //TODO: what if file_header->link_target == NULL (say, corrupted tarball?)
 146                 res = symlink(file_header->link_target, file_header->name);
 147                 if ((res == -1)
 148                  && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
 149                 ) {
 150                         bb_perror_msg("can't create %slink "
 151                                 "from %s to %s", "sym",
 152                                 file_header->name,
 153                                 file_header->link_target);
 154                 }
 155                 break;
 156         case S_IFSOCK:
 157         case S_IFBLK:
 158         case S_IFCHR:
 159         case S_IFIFO:
 160                 res = mknod(file_header->name, file_header->mode, file_header->device);
 161                 if ((res == -1)
 162                  && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
 163                 ) {
 164                         bb_perror_msg("can't create node %s", file_header->name);
 165                 }
 166                 break;
 167         default:
 168                 bb_error_msg_and_die("unrecognized file type");
 169         }
 170
 171         if (!S_ISLNK(file_header->mode)) {
 172                 if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_OWNER)) {
 173                         uid_t uid = file_header->uid;
 174                         gid_t gid = file_header->gid;
 175 #if ENABLE_FEATURE_TAR_UNAME_GNAME
 176                         if (!(archive_handle->ah_flags & ARCHIVE_NUMERIC_OWNER)) {
 177                                 if (file_header->tar__uname) {
 178 //TODO: cache last name/id pair?
 179                                         struct passwd *pwd = getpwnam(file_header->tar__uname);
 180                                         if (pwd) uid = pwd->pw_uid;
 181                                 }
 182                                 if (file_header->tar__gname) {
 183                                         struct group *grp = getgrnam(file_header->tar__gname);
 184                                         if (grp) gid = grp->gr_gid;
 185                                 }
 186                         }
 187 #endif
 188                         /* GNU tar 1.15.1 uses chown, not lchown */
 189                         chown(file_header->name, uid, gid);
 190                 }
 191                 /* uclibc has no lchmod, glibc is even stranger -
 192                  * it has lchmod which seems to do nothing!
 193                  * so we use chmod... */
 194                 if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_PERM)) {
 195                         chmod(file_header->name, file_header->mode);
 196                 }
 197                 if (archive_handle->ah_flags & ARCHIVE_RESTORE_DATE) {
 198                         struct timeval t[2];
 199
 200                         t[1].tv_sec = t[0].tv_sec = file_header->mtime;
 201                         t[1].tv_usec = t[0].tv_usec = 0;
 202                         utimes(file_header->name, t);
 203                 }
 204         }
 205
 206  ret: ;
 207 #if ENABLE_FEATURE_TAR_SELINUX
 208         if (sctx) {
 209                 /* reset the context after creating an entry */
 210                 setfscreatecon(NULL);
 211         }
 212 #endif
 213 }