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
  10 //usage:#define rpm2cpio_trivial_usage
  11 //usage:       "package.rpm"
  12 //usage:#define rpm2cpio_full_usage "\n\n"
  13 //usage:       "Output a cpio archive of the rpm file"
  14
  15 #include "libbb.h"
  16 #include "bb_archive.h"
  17 #include "rpm.h"
  18
  19 enum { rpm_fd = STDIN_FILENO };
  20
  21 static unsigned skip_header(void)
  22 {
  23         struct rpm_header header;
  24         unsigned len;
  25
  26         xread(rpm_fd, &header, sizeof(header));
  27 //      if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC_STR, 3) != 0) {
  28 //              bb_error_msg_and_die("invalid RPM header magic");
  29 //      }
  30 //      if (header.version != 1) {
  31 //              bb_error_msg_and_die("unsupported RPM header version");
  32 //      }
  33         if (header.magic_and_ver != htonl(RPM_HEADER_MAGICnVER)) {
  34                 bb_error_msg_and_die("invalid RPM header magic or unsupported version");
  35                 // ": %x != %x", header.magic_and_ver, htonl(RPM_HEADER_MAGICnVER));
  36         }
  37
  38         /* Seek past index entries, and past store */
  39         len = 16 * ntohl(header.entries) + ntohl(header.size);
  40         seek_by_jump(rpm_fd, len);
  41
  42         return sizeof(header) + len;
  43 }
  44
  45 /* No getopt required */
  46 int rpm2cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  47 int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
  48 {
  49         struct rpm_lead lead;
  50         unsigned pos;
  51
  52         if (argv[1]) {
  53                 xmove_fd(xopen(argv[1], O_RDONLY), rpm_fd);
  54         }
  55         xread(rpm_fd, &lead, sizeof(lead));
  56
  57         /* Just check the magic, the rest is irrelevant */
  58         if (lead.magic != htonl(RPM_LEAD_MAGIC)) {
  59                 bb_error_msg_and_die("invalid RPM magic");
  60         }
  61
  62         /* Skip the signature header, align to 8 bytes */
  63         pos = skip_header();
  64         seek_by_jump(rpm_fd, (-(int)pos) & 7);
  65
  66         /* Skip the main header */
  67         skip_header();
  68
  69 #if 0
  70         /* This works, but doesn't report uncompress errors (they happen in child) */
  71         setup_unzip_on_fd(rpm_fd /*fail_if_not_detected: 1*/);
  72         if (bb_copyfd_eof(rpm_fd, STDOUT_FILENO) < 0)
  73                 bb_error_msg_and_die("error unpacking");
  74 #else
  75         /* BLOAT */
  76         {
  77                 union {
  78                         uint8_t b[4];
  79                         uint16_t b16[2];
  80                         uint32_t b32[1];
  81                 } magic;
  82                 IF_DESKTOP(long long) int FAST_FUNC (*unpack)(int src_fd, int dst_fd);
  83
  84                 xread(rpm_fd, magic.b16, sizeof(magic.b16[0]));
  85                 if (magic.b16[0] == GZIP_MAGIC) {
  86                         unpack = unpack_gz_stream;
  87                 } else
  88                 if (ENABLE_FEATURE_SEAMLESS_BZ2
  89                  && magic.b16[0] == BZIP2_MAGIC
  90                 ) {
  91                         unpack = unpack_bz2_stream;
  92                 } else
  93                 if (ENABLE_FEATURE_SEAMLESS_XZ
  94                  && magic.b16[0] == XZ_MAGIC1
  95                 ) {
  96                         xread(rpm_fd, magic.b32, sizeof(magic.b32[0]));
  97                         if (magic.b32[0] != XZ_MAGIC2)
  98                                 goto no_magic;
  99                         /* unpack_xz_stream wants fd at position 6, no need to seek */
 100                         //xlseek(rpm_fd, -6, SEEK_CUR);
 101                         unpack = unpack_xz_stream;
 102                 } else {
 103  no_magic:
 104                         bb_error_msg_and_die("no gzip"
 105                                         IF_FEATURE_SEAMLESS_BZ2("/bzip2")
 106                                         IF_FEATURE_SEAMLESS_XZ("/xz")
 107                                         " magic");
 108                 }
 109                 if (unpack(rpm_fd, STDOUT_FILENO) < 0)
 110                         bb_error_msg_and_die("error unpacking");
 111         }
 112 #endif
 113
 114         if (ENABLE_FEATURE_CLEAN_UP) {
 115                 close(rpm_fd);
 116         }
 117
 118         return 0;
 119 }