src/split/split.c

   1 /*
   2  * dpkg-split - splitting and joining of multipart *.deb archives
   3  * split.c - splitting archives
   4  *
   5  * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright © 2008-2015 Guillem Jover <guillem@debian.org>
   7  *
   8  * This is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <config.h>
  23 #include <compat.h>
  24
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <sys/wait.h>
  28
  29 #include <errno.h>
  30 #include <limits.h>
  31 #include <inttypes.h>
  32 #include <fcntl.h>
  33 #include <libgen.h>
  34 #include <string.h>
  35 #include <time.h>
  36 #include <unistd.h>
  37 #include <stdint.h>
  38 #include <stdlib.h>
  39 #include <stdio.h>
  40
  41 #include <dpkg/i18n.h>
  42 #include <dpkg/c-ctype.h>
  43 #include <dpkg/dpkg.h>
  44 #include <dpkg/dpkg-db.h>
  45 #include <dpkg/parsedump.h>
  46 #include <dpkg/path.h>
  47 #include <dpkg/string.h>
  48 #include <dpkg/subproc.h>
  49 #include <dpkg/buffer.h>
  50 #include <dpkg/ar.h>
  51 #include <dpkg/options.h>
  52
  53 #include "dpkg-split.h"
  54
  55 /**
  56  * Parse the control file from a .deb package into a struct pkginfo.
  57  */
  58 static struct pkginfo *
  59 deb_parse_control(const char *filename)
  60 {
  61         struct parsedb_state *ps;
  62         struct pkginfo *pkg;
  63         pid_t pid;
  64         int p[2];
  65
  66         m_pipe(p);
  67
  68         pid = subproc_fork();
  69         if (pid == 0) {
  70                 /* Child writes to pipe. */
  71                 m_dup2(p[1], 1);
  72                 close(p[0]);
  73                 close(p[1]);
  74
  75                 execlp(BACKEND, BACKEND, "--info", filename, "control", NULL);
  76                 ohshite(_("unable to execute %s (%s)"),
  77                         _("package field value extraction"), BACKEND);
  78         }
  79         close(p[1]);
  80
  81         /* Parent reads from pipe. */
  82         ps = parsedb_new(_("<dpkg-deb --info pipe>"), p[0], pdb_parse_binary);
  83         parsedb_load(ps);
  84         parsedb_parse(ps, &pkg);
  85         parsedb_close(ps);
  86
  87         close(p[0]);
  88
  89         subproc_reap(pid, _("package field value extraction"), SUBPROC_NOPIPE);
  90
  91         return pkg;
  92 }
  93
  94 static intmax_t
  95 parse_timestamp(const char *value)
  96 {
  97         intmax_t timestamp;
  98         char *end;
  99
 100         errno = 0;
 101         timestamp = strtoimax(value, &end, 10);
 102         if (value == end || *end)
 103                 ohshit(_("unable to parse timestamp '%.255s'"), value);
 104         else if (errno != 0)
 105                 ohshite(_("unable to parse timestamp '%.255s'"), value);
 106
 107         return timestamp;
 108 }
 109
 110 /* Cleanup filename for use in crippled msdos systems. */
 111 static char *
 112 clean_msdos_filename(char *filename)
 113 {
 114         char *d, *s;
 115
 116         for (s = d = filename; *s; d++, s++) {
 117                 if (*s == '+')
 118                         *d = 'x';
 119                 else if (c_isupper(*s))
 120                         *d = c_tolower(*s);
 121                 else if (c_islower(*s) || c_isdigit(*s))
 122                         *d = *s;
 123                 else
 124                         s++;
 125         }
 126
 127         return filename;
 128 }
 129
 130 static int
 131 mksplit(const char *file_src, const char *prefix, off_t maxpartsize,
 132         bool msdos)
 133 {
 134         struct pkginfo *pkg;
 135         struct dpkg_error err;
 136         int fd_src;
 137         struct stat st;
 138         intmax_t timestamp;
 139         const char *timestamp_str;
 140         const char *version;
 141         char hash[MD5HASHLEN + 1];
 142         int nparts, curpart;
 143         off_t partsize;
 144         off_t cur_partsize, last_partsize;
 145         char *prefixdir = NULL, *msdos_prefix = NULL;
 146         struct varbuf file_dst = VARBUF_INIT;
 147         struct varbuf partmagic = VARBUF_INIT;
 148         struct varbuf partname = VARBUF_INIT;
 149
 150         fd_src = open(file_src, O_RDONLY);
 151         if (fd_src < 0)
 152                 ohshite(_("unable to open source file '%.250s'"), file_src);
 153         if (fstat(fd_src, &st))
 154                 ohshite(_("unable to fstat source file"));
 155         if (!S_ISREG(st.st_mode))
 156                 ohshit(_("source file '%.250s' not a plain file"), file_src);
 157
 158         if (fd_md5(fd_src, hash, -1, &err) < 0)
 159                 ohshit(_("cannot compute MD5 digest for file '%s': %s"),
 160                        file_src, err.str);
 161         lseek(fd_src, 0, SEEK_SET);
 162
 163         pkg  = deb_parse_control(file_src);
 164         version = versiondescribe(&pkg->available.version, vdew_nonambig);
 165
 166         timestamp_str = getenv("SOURCE_DATE_EPOCH");
 167         if (str_is_set(timestamp_str))
 168                 timestamp = parse_timestamp(timestamp_str);
 169         else
 170                 timestamp = time(NULL);
 171
 172         partsize = maxpartsize - HEADERALLOWANCE;
 173         last_partsize = st.st_size % partsize;
 174         if (last_partsize == 0)
 175                 last_partsize = partsize;
 176         nparts = (st.st_size + partsize - 1) / partsize;
 177
 178         printf(P_("Splitting package %s into %d part: ",
 179                   "Splitting package %s into %d parts: ", nparts),
 180                pkg->set->name, nparts);
 181
 182         if (msdos) {
 183                 char *t;
 184
 185                 t = m_strdup(prefix);
 186                 prefixdir = m_strdup(dirname(t));
 187                 free(t);
 188
 189                 msdos_prefix = m_strdup(path_basename(prefix));
 190                 prefix = clean_msdos_filename(msdos_prefix);
 191         }
 192
 193         for (curpart = 1; curpart <= nparts; curpart++) {
 194                 struct dpkg_ar *ar;
 195
 196                 /* Generate output filename. */
 197                 if (msdos) {
 198                         char *refname;
 199                         int prefix_max;
 200
 201                         refname = str_fmt("%dof%d", curpart, nparts);
 202                         prefix_max = max(8 - strlen(refname), 0);
 203                         varbuf_set_fmt(&file_dst, "%s/%.*s%.8s" DEBEXT,
 204                                        prefixdir, prefix_max, prefix, refname);
 205                         free(refname);
 206                 } else {
 207                         varbuf_set_fmt(&file_dst, "%s.%dof%d" DEBEXT,
 208                                        prefix, curpart, nparts);
 209                 }
 210
 211                 if (curpart == nparts)
 212                         cur_partsize = last_partsize;
 213                 else
 214                         cur_partsize = partsize;
 215
 216                 if (cur_partsize > maxpartsize) {
 217                         ohshit(_("header is too long, making part too long; "
 218                                  "the package name or version\n"
 219                                  "numbers must be extraordinarily long, "
 220                                  "or something; giving up"));
 221                 }
 222
 223                 /* Split the data. */
 224                 ar = dpkg_ar_create(file_dst.buf, 0644);
 225                 dpkg_ar_set_mtime(ar, timestamp);
 226
 227                 /* Write the ar header. */
 228                 dpkg_ar_put_magic(ar);
 229
 230                 /* Write the debian-split part. */
 231                 varbuf_set_fmt(&partmagic,
 232                                "%s\n%s\n%s\n%s\n%jd\n%jd\n%d/%d\n%s\n",
 233                                SPLITVERSION, pkg->set->name, version, hash,
 234                                (intmax_t)st.st_size, (intmax_t)partsize,
 235                                curpart, nparts, pkg->available.arch->name);
 236                 dpkg_ar_member_put_mem(ar, PARTMAGIC,
 237                                        partmagic.buf, partmagic.used);
 238
 239                 /* Write the data part. */
 240                 varbuf_set_fmt(&partname, "data.%d", curpart);
 241                 dpkg_ar_member_put_file(ar, partname.buf,
 242                                         fd_src, cur_partsize);
 243
 244                 dpkg_ar_close(ar);
 245
 246                 printf("%d ", curpart);
 247         }
 248
 249         varbuf_destroy(&file_dst);
 250         varbuf_destroy(&partname);
 251         varbuf_destroy(&partmagic);
 252
 253         free(prefixdir);
 254         free(msdos_prefix);
 255
 256         close(fd_src);
 257
 258         printf(_("done\n"));
 259
 260         return 0;
 261 }
 262
 263 int
 264 do_split(const char *const *argv)
 265 {
 266         const char *sourcefile, *prefix;
 267
 268         sourcefile = *argv++;
 269         if (!sourcefile)
 270                 badusage(_("--split needs a source filename argument"));
 271         prefix = *argv++;
 272         if (prefix && *argv)
 273                 badusage(_("--split takes at most a source filename and destination prefix"));
 274         if (!prefix) {
 275                 size_t sourcefile_len = strlen(sourcefile);
 276
 277                 if (str_match_end(sourcefile, DEBEXT))
 278                         sourcefile_len -= strlen(DEBEXT);
 279
 280                 prefix = nfstrnsave(sourcefile, sourcefile_len);
 281         }
 282
 283         mksplit(sourcefile, prefix, opt_maxpartsize, opt_msdos);
 284
 285         return 0;
 286 }