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 || errno != 0)
 103                 ohshite(_("unable to parse timestamp '%.255s'"), value);
 104
 105         return timestamp;
 106 }
 107
 108 /* Cleanup filename for use in crippled msdos systems. */
 109 static char *
 110 clean_msdos_filename(char *filename)
 111 {
 112         char *d, *s;
 113
 114         for (s = d = filename; *s; d++, s++) {
 115                 if (*s == '+')
 116                         *d = 'x';
 117                 else if (c_isupper(*s))
 118                         *d = c_tolower(*s);
 119                 else if (c_islower(*s) || c_isdigit(*s))
 120                         *d = *s;
 121                 else
 122                         s++;
 123         }
 124
 125         return filename;
 126 }
 127
 128 static int
 129 mksplit(const char *file_src, const char *prefix, off_t maxpartsize,
 130         bool msdos)
 131 {
 132         struct pkginfo *pkg;
 133         struct dpkg_error err;
 134         int fd_src;
 135         struct stat st;
 136         intmax_t timestamp;
 137         const char *timestamp_str;
 138         const char *version;
 139         char hash[MD5HASHLEN + 1];
 140         int nparts, curpart;
 141         off_t partsize;
 142         off_t cur_partsize, last_partsize;
 143         char *prefixdir = NULL, *msdos_prefix = NULL;
 144         struct varbuf file_dst = VARBUF_INIT;
 145         struct varbuf partmagic = VARBUF_INIT;
 146         struct varbuf partname = VARBUF_INIT;
 147
 148         fd_src = open(file_src, O_RDONLY);
 149         if (fd_src < 0)
 150                 ohshite(_("unable to open source file '%.250s'"), file_src);
 151         if (fstat(fd_src, &st))
 152                 ohshite(_("unable to fstat source file"));
 153         if (!S_ISREG(st.st_mode))
 154                 ohshit(_("source file '%.250s' not a plain file"), file_src);
 155
 156         if (fd_md5(fd_src, hash, -1, &err) < 0)
 157                 ohshit(_("cannot compute MD5 digest for file '%s': %s"),
 158                        file_src, err.str);
 159         lseek(fd_src, 0, SEEK_SET);
 160
 161         pkg  = deb_parse_control(file_src);
 162         version = versiondescribe(&pkg->available.version, vdew_nonambig);
 163
 164         timestamp_str = getenv("SOURCE_DATE_EPOCH");
 165         if (timestamp_str)
 166                 timestamp = parse_timestamp(timestamp_str);
 167         else
 168                 timestamp = time(NULL);
 169
 170         partsize = maxpartsize - HEADERALLOWANCE;
 171         last_partsize = st.st_size % partsize;
 172         if (last_partsize == 0)
 173                 last_partsize = partsize;
 174         nparts = (st.st_size + partsize - 1) / partsize;
 175
 176         printf(P_("Splitting package %s into %d part: ",
 177                   "Splitting package %s into %d parts: ", nparts),
 178                pkg->set->name, nparts);
 179
 180         if (msdos) {
 181                 char *t;
 182
 183                 t = m_strdup(prefix);
 184                 prefixdir = m_strdup(dirname(t));
 185                 free(t);
 186
 187                 msdos_prefix = m_strdup(path_basename(prefix));
 188                 prefix = clean_msdos_filename(msdos_prefix);
 189         }
 190
 191         for (curpart = 1; curpart <= nparts; curpart++) {
 192                 struct dpkg_ar *ar;
 193
 194                 varbuf_reset(&file_dst);
 195                 /* Generate output filename. */
 196                 if (msdos) {
 197                         char *refname;
 198                         int prefix_max;
 199
 200                         refname = str_fmt("%dof%d", curpart, nparts);
 201                         prefix_max = max(8 - strlen(refname), 0);
 202                         varbuf_printf(&file_dst, "%s/%.*s%.8s" DEBEXT,
 203                                       prefixdir, prefix_max, prefix, refname);
 204                         free(refname);
 205                 } else {
 206                         varbuf_printf(&file_dst, "%s.%dof%d" DEBEXT,
 207                                       prefix, curpart, nparts);
 208                 }
 209
 210                 if (curpart == nparts)
 211                         cur_partsize = last_partsize;
 212                 else
 213                         cur_partsize = partsize;
 214
 215                 if (cur_partsize > maxpartsize) {
 216                         ohshit(_("header is too long, making part too long; "
 217                                  "the package name or version\n"
 218                                  "numbers must be extraordinarily long, "
 219                                  "or something; giving up"));
 220                 }
 221
 222                 /* Split the data. */
 223                 ar = dpkg_ar_create(file_dst.buf, 0644);
 224                 dpkg_ar_set_mtime(ar, timestamp);
 225
 226                 /* Write the ar header. */
 227                 dpkg_ar_put_magic(ar);
 228
 229                 /* Write the debian-split part. */
 230                 varbuf_printf(&partmagic,
 231                               "%s\n%s\n%s\n%s\n%jd\n%jd\n%d/%d\n%s\n",
 232                               SPLITVERSION, pkg->set->name, version, hash,
 233                               (intmax_t)st.st_size, (intmax_t)partsize,
 234                               curpart, nparts, pkg->available.arch->name);
 235                 dpkg_ar_member_put_mem(ar, PARTMAGIC,
 236                                        partmagic.buf, partmagic.used);
 237                 varbuf_reset(&partmagic);
 238
 239                 /* Write the data part. */
 240                 varbuf_printf(&partname, "data.%d", curpart);
 241                 dpkg_ar_member_put_file(ar, partname.buf,
 242                                         fd_src, cur_partsize);
 243                 varbuf_reset(&partname);
 244
 245                 dpkg_ar_close(ar);
 246
 247                 printf("%d ", curpart);
 248         }
 249
 250         varbuf_destroy(&file_dst);
 251         varbuf_destroy(&partname);
 252         varbuf_destroy(&partmagic);
 253
 254         free(prefixdir);
 255         free(msdos_prefix);
 256
 257         close(fd_src);
 258
 259         printf(_("done\n"));
 260
 261         return 0;
 262 }
 263
 264 int
 265 do_split(const char *const *argv)
 266 {
 267         const char *sourcefile, *prefix;
 268
 269         sourcefile = *argv++;
 270         if (!sourcefile)
 271                 badusage(_("--split needs a source filename argument"));
 272         prefix = *argv++;
 273         if (prefix && *argv)
 274                 badusage(_("--split takes at most a source filename and destination prefix"));
 275         if (!prefix) {
 276                 size_t sourcefile_len = strlen(sourcefile);
 277
 278                 if (str_match_end(sourcefile, DEBEXT))
 279                         sourcefile_len -= strlen(DEBEXT);
 280
 281                 prefix = nfstrnsave(sourcefile, sourcefile_len);
 282         }
 283
 284         mksplit(sourcefile, prefix, opt_maxpartsize, opt_msdos);
 285
 286         return 0;
 287 }