release/src/router/busybox/archival/ar.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini ar implementation for busybox
   4  *
   5  * Copyright (C) 2000 by Glenn McGrath
   6  *
   7  * Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
   8  *
   9  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  10  *
  11  * Archive creation support:
  12  * Copyright (C) 2010 Nokia Corporation. All rights reserved.
  13  * Written by Alexander Shishkin.
  14  *
  15  * There is no single standard to adhere to so ar may not portable
  16  * between different systems
  17  * http://www.unix-systems.org/single_unix_specification_v2/xcu/ar.html
  18  */
  19
  20 //usage:#define ar_trivial_usage
  21 //usage:       "[-o] [-v] [-p] [-t] [-x] ARCHIVE FILES"
  22 //usage:#define ar_full_usage "\n\n"
  23 //usage:       "Extract or list FILES from an ar archive\n"
  24 //usage:     "\n        -o      Preserve original dates"
  25 //usage:     "\n        -p      Extract to stdout"
  26 //usage:     "\n        -t      List"
  27 //usage:     "\n        -x      Extract"
  28 //usage:     "\n        -v      Verbose"
  29
  30 #include "libbb.h"
  31 #include "bb_archive.h"
  32 #include "ar.h"
  33
  34 #if ENABLE_FEATURE_AR_CREATE
  35 /* filter out entries with same names as specified on the command line */
  36 static char FAST_FUNC filter_replaceable(archive_handle_t *handle)
  37 {
  38         if (find_list_entry(handle->accept, handle->file_header->name))
  39                 return EXIT_FAILURE;
  40
  41         return EXIT_SUCCESS;
  42 }
  43
  44 static void output_ar_header(archive_handle_t *handle)
  45 {
  46         /* GNU ar 2.19.51.0.14 creates malformed archives
  47          * if input files are >10G. It also truncates files >4GB
  48          * (uses "size mod 4G"). We abort in this case:
  49          * We could add support for up to 10G files, but this is unlikely to be useful.
  50          * Note that unpacking side limits all fields to "unsigned int" data type,
  51          * and treats "all ones" as an error indicator. Thus max we allow here is UINT_MAX-1.
  52          */
  53         enum {
  54                 /* for 2nd field: mtime */
  55                 MAX11CHARS = UINT_MAX > 0xffffffff ? (unsigned)99999999999 : UINT_MAX-1,
  56                 /* for last field: filesize */
  57                 MAX10CHARS = UINT_MAX > 0xffffffff ? (unsigned)9999999999 : UINT_MAX-1,
  58         };
  59
  60         struct file_header_t *fh = handle->file_header;
  61
  62         if (handle->offset & 1) {
  63                 xwrite(handle->src_fd, "\n", 1);
  64                 handle->offset++;
  65         }
  66
  67         /* Careful! The widths should be exact. Fields must be separated */
  68         if (sizeof(off_t) > 4 && fh->size > (off_t)MAX10CHARS) {
  69                 bb_error_msg_and_die("'%s' is bigger than ar can handle", fh->name);
  70         }
  71         fdprintf(handle->src_fd, "%-16.16s%-12lu%-6u%-6u%-8o%-10"OFF_FMT"u`\n",
  72                         fh->name,
  73                         (sizeof(time_t) > 4 && fh->mtime > MAX11CHARS) ? (long)0 : (long)fh->mtime,
  74                         fh->uid > 99999 ? 0 : (int)fh->uid,
  75                         fh->gid > 99999 ? 0 : (int)fh->gid,
  76                         (int)fh->mode & 07777777,
  77                         fh->size
  78         );
  79
  80         handle->offset += AR_HEADER_LEN;
  81 }
  82
  83 /*
  84  * when replacing files in an existing archive, copy from the
  85  * original archive those files that are to be left intact
  86  */
  87 static void FAST_FUNC copy_data(archive_handle_t *handle)
  88 {
  89         archive_handle_t *out_handle = handle->ar__out;
  90         struct file_header_t *fh = handle->file_header;
  91
  92         out_handle->file_header = fh;
  93         output_ar_header(out_handle);
  94
  95         bb_copyfd_exact_size(handle->src_fd, out_handle->src_fd, fh->size);
  96         out_handle->offset += fh->size;
  97 }
  98
  99 static int write_ar_header(archive_handle_t *handle)
 100 {
 101         char *fn;
 102         char fn_h[17]; /* 15 + "/" + NUL */
 103         struct stat st;
 104         int fd;
 105
 106         fn = llist_pop(&handle->accept);
 107         if (!fn)
 108                 return -1;
 109
 110         xstat(fn, &st);
 111
 112         handle->file_header->mtime = st.st_mtime;
 113         handle->file_header->uid = st.st_uid;
 114         handle->file_header->gid = st.st_gid;
 115         handle->file_header->mode = st.st_mode;
 116         handle->file_header->size = st.st_size;
 117         handle->file_header->name = fn_h;
 118 //TODO: if ENABLE_FEATURE_AR_LONG_FILENAMES...
 119         sprintf(fn_h, "%.15s/", bb_basename(fn));
 120
 121         output_ar_header(handle);
 122
 123         fd = xopen(fn, O_RDONLY);
 124         bb_copyfd_exact_size(fd, handle->src_fd, st.st_size);
 125         close(fd);
 126         handle->offset += st.st_size;
 127
 128         return 0;
 129 }
 130
 131 static int write_ar_archive(archive_handle_t *handle)
 132 {
 133         struct stat st;
 134         archive_handle_t *out_handle;
 135
 136         xfstat(handle->src_fd, &st, handle->ar__name);
 137
 138         /* if archive exists, create a new handle for output.
 139          * we create it in place of the old one.
 140          */
 141         if (st.st_size != 0) {
 142                 out_handle = init_handle();
 143                 xunlink(handle->ar__name);
 144                 out_handle->src_fd = xopen(handle->ar__name, O_WRONLY | O_CREAT | O_TRUNC);
 145                 out_handle->accept = handle->accept;
 146         } else {
 147                 out_handle = handle;
 148         }
 149
 150         handle->ar__out = out_handle;
 151
 152         xwrite(out_handle->src_fd, AR_MAGIC "\n", AR_MAGIC_LEN + 1);
 153         out_handle->offset += AR_MAGIC_LEN + 1;
 154
 155         /* skip to the end of the archive if we have to append stuff */
 156         if (st.st_size != 0) {
 157                 handle->filter = filter_replaceable;
 158                 handle->action_data = copy_data;
 159                 unpack_ar_archive(handle);
 160         }
 161
 162         while (write_ar_header(out_handle) == 0)
 163                 continue;
 164
 165         /* optional, since we exit right after we return */
 166         if (ENABLE_FEATURE_CLEAN_UP) {
 167                 close(handle->src_fd);
 168                 if (out_handle->src_fd != handle->src_fd)
 169                         close(out_handle->src_fd);
 170         }
 171
 172         return EXIT_SUCCESS;
 173 }
 174 #endif /* FEATURE_AR_CREATE */
 175
 176 static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
 177 {
 178         const char *mode = bb_mode_string(file_header->mode);
 179         char *mtime;
 180
 181         mtime = ctime(&file_header->mtime);
 182         mtime[16] = ' ';
 183         memmove(&mtime[17], &mtime[20], 4);
 184         mtime[21] = '\0';
 185         printf("%s %u/%u%7"OFF_FMT"u %s %s\n", &mode[1],
 186                         (int)file_header->uid, (int)file_header->gid,
 187                         file_header->size,
 188                         &mtime[4], file_header->name
 189         );
 190 }
 191
 192 #define AR_OPT_VERBOSE          (1 << 0)
 193 #define AR_OPT_PRESERVE_DATE    (1 << 1)
 194 /* "ar r" implies create, but warns about it. c suppresses warning.
 195  * bbox accepts but ignores it: */
 196 #define AR_OPT_CREATE           (1 << 2)
 197
 198 #define AR_CMD_PRINT            (1 << 3)
 199 #define FIRST_CMD               AR_CMD_PRINT
 200 #define AR_CMD_LIST             (1 << 4)
 201 #define AR_CMD_EXTRACT          (1 << 5)
 202 #define AR_CMD_INSERT           (1 << 6)
 203
 204 int ar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 205 int ar_main(int argc UNUSED_PARAM, char **argv)
 206 {
 207         archive_handle_t *archive_handle;
 208         unsigned opt, t;
 209
 210         archive_handle = init_handle();
 211
 212         /* --: prepend '-' to the first argument if required */
 213         /* -1: at least one param is reqd */
 214         /* one of p,t,x[,r] is required */
 215         opt_complementary = "--:-1:p:t:x"IF_FEATURE_AR_CREATE(":r");
 216         opt = getopt32(argv, "voc""ptx"IF_FEATURE_AR_CREATE("r"));
 217         argv += optind;
 218
 219         t = opt / FIRST_CMD;
 220         if (t & (t-1)) /* more than one of p,t,x[,r] are specified */
 221                 bb_show_usage();
 222
 223         if (opt & AR_CMD_PRINT) {
 224                 archive_handle->action_data = data_extract_to_stdout;
 225         }
 226         if (opt & AR_CMD_LIST) {
 227                 archive_handle->action_header = header_list;
 228         }
 229         if (opt & AR_CMD_EXTRACT) {
 230                 archive_handle->action_data = data_extract_all;
 231         }
 232         if (opt & AR_OPT_PRESERVE_DATE) {
 233                 archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
 234         }
 235         if (opt & AR_OPT_VERBOSE) {
 236                 archive_handle->action_header = header_verbose_list_ar;
 237         }
 238 #if ENABLE_FEATURE_AR_CREATE
 239         archive_handle->ar__name = *argv;
 240 #endif
 241         archive_handle->src_fd = xopen(*argv++,
 242                         (opt & AR_CMD_INSERT)
 243                                 ? O_RDWR | O_CREAT
 244                                 : O_RDONLY
 245         );
 246
 247         if (*argv)
 248                 archive_handle->filter = filter_accept_list;
 249         while (*argv) {
 250                 llist_add_to_end(&archive_handle->accept, *argv++);
 251         }
 252
 253 #if ENABLE_FEATURE_AR_CREATE
 254         if (opt & AR_CMD_INSERT)
 255                 return write_ar_archive(archive_handle);
 256 #endif
 257
 258         unpack_ar_archive(archive_handle);
 259
 260         return EXIT_SUCCESS;
 261 }