archival/rpm2cpio.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini rpm2cpio implementation for busybox
   4  *
   5  * Copyright (C) 2001 by Laurence Anderson
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9 #include "libbb.h"
  10 #include "archive.h"
  11 #include "rpm.h"
  12
  13 enum { rpm_fd = STDIN_FILENO };
  14
  15 static unsigned skip_header(void)
  16 {
  17         struct rpm_header header;
  18         unsigned len;
  19
  20         xread(rpm_fd, &header, sizeof(header));
  21 //      if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC_STR, 3) != 0) {
  22 //              bb_error_msg_and_die("invalid RPM header magic");
  23 //      }
  24 //      if (header.version != 1) {
  25 //              bb_error_msg_and_die("unsupported RPM header version");
  26 //      }
  27         if (header.magic_and_ver != htonl(RPM_HEADER_MAGICnVER)) {
  28                 bb_error_msg_and_die("invalid RPM header magic or unsupported version");
  29                 // ": %x != %x", header.magic_and_ver, htonl(RPM_HEADER_MAGICnVER));
  30         }
  31
  32         /* Seek past index entries, and past store */
  33         len = 16 * ntohl(header.entries) + ntohl(header.size);
  34         seek_by_jump(rpm_fd, len);
  35
  36         return sizeof(header) + len;
  37 }
  38
  39 /* No getopt required */
  40 int rpm2cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  41 int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
  42 {
  43         struct rpm_lead lead;
  44         unsigned pos;
  45
  46         if (argv[1]) {
  47                 xmove_fd(xopen(argv[1], O_RDONLY), rpm_fd);
  48         }
  49         xread(rpm_fd, &lead, sizeof(lead));
  50
  51         /* Just check the magic, the rest is irrelevant */
  52         if (lead.magic != htonl(RPM_LEAD_MAGIC)) {
  53                 bb_error_msg_and_die("invalid RPM magic");
  54         }
  55
  56         /* Skip the signature header, align to 8 bytes */
  57         pos = skip_header();
  58         seek_by_jump(rpm_fd, (-(int)pos) & 7);
  59
  60         /* Skip the main header */
  61         skip_header();
  62
  63 #if 0
  64         /* This works, but doesn't report uncompress errors (they happen in child) */
  65         setup_unzip_on_fd(rpm_fd /*fail_if_not_detected: 1*/);
  66         if (bb_copyfd_eof(rpm_fd, STDOUT_FILENO) < 0)
  67                 bb_error_msg_and_die("error unpacking");
  68 #else
  69         /* BLOAT */
  70         {
  71                 union {
  72                         uint8_t b[4];
  73                         uint16_t b16[2];
  74                         uint32_t b32[1];
  75                 } magic;
  76                 IF_DESKTOP(long long) int FAST_FUNC (*unpack)(int src_fd, int dst_fd);
  77
  78                 xread(rpm_fd, magic.b16, sizeof(magic.b16[0]));
  79                 if (magic.b16[0] == GZIP_MAGIC) {
  80                         unpack = unpack_gz_stream;
  81                 } else
  82                 if (ENABLE_FEATURE_SEAMLESS_BZ2
  83                  && magic.b16[0] == BZIP2_MAGIC
  84                 ) {
  85                         unpack = unpack_bz2_stream;
  86                 } else
  87                 if (ENABLE_FEATURE_SEAMLESS_XZ
  88                  && magic.b16[0] == XZ_MAGIC1
  89                 ) {
  90                         xread(rpm_fd, magic.b32, sizeof(magic.b32[0]));
  91                         if (magic.b32[0] != XZ_MAGIC2)
  92                                 goto no_magic;
  93                         /* unpack_xz_stream wants fd at position 6, no need to seek */
  94                         //xlseek(rpm_fd, -6, SEEK_CUR);
  95                         unpack = unpack_xz_stream;
  96                 } else {
  97  no_magic:
  98                         bb_error_msg_and_die("no gzip"
  99                                         IF_FEATURE_SEAMLESS_BZ2("/bzip2")
 100                                         IF_FEATURE_SEAMLESS_XZ("/xz")
 101                                         " magic");
 102                 }
 103                 if (unpack(rpm_fd, STDOUT_FILENO) < 0)
 104                         bb_error_msg_and_die("error unpacking");
 105         }
 106 #endif
 107
 108         if (ENABLE_FEATURE_CLEAN_UP) {
 109                 close(rpm_fd);
 110         }
 111
 112         return 0;
 113 }