diff options
Diffstat (limited to 'archival/rpm2cpio.c')
-rw-r--r-- | archival/rpm2cpio.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/archival/rpm2cpio.c b/archival/rpm2cpio.c new file mode 100644 index 0000000..ee93871 --- /dev/null +++ b/archival/rpm2cpio.c @@ -0,0 +1,89 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini rpm2cpio implementation for busybox + * + * Copyright (C) 2001 by Laurence Anderson + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ +#include "libbb.h" +#include "unarchive.h" + +#define RPM_MAGIC "\355\253\356\333" +#define RPM_HEADER_MAGIC "\216\255\350" + +struct rpm_lead { + unsigned char magic[4]; + uint8_t major, minor; + uint16_t type; + uint16_t archnum; + char name[66]; + uint16_t osnum; + uint16_t signature_type; + char reserved[16]; +}; + +struct rpm_header { + char magic[3]; /* 3 byte magic: 0x8e 0xad 0xe8 */ + uint8_t version; /* 1 byte version number */ + uint32_t reserved; /* 4 bytes reserved */ + uint32_t entries; /* Number of entries in header (4 bytes) */ + uint32_t size; /* Size of store (4 bytes) */ +}; + +static void skip_header(int rpm_fd) +{ + struct rpm_header header; + + xread(rpm_fd, &header, sizeof(struct rpm_header)); + if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC, 3) != 0) { + bb_error_msg_and_die("invalid RPM header magic"); /* Invalid magic */ + } + if (header.version != 1) { + bb_error_msg_and_die("unsupported RPM header version"); /* This program only supports v1 headers */ + } + header.entries = ntohl(header.entries); + header.size = ntohl(header.size); + lseek (rpm_fd, 16 * header.entries, SEEK_CUR); /* Seek past index entries */ + lseek (rpm_fd, header.size, SEEK_CUR); /* Seek past store */ +} + +/* No getopt required */ +int rpm2cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int rpm2cpio_main(int argc, char **argv) +{ + struct rpm_lead lead; + int rpm_fd; + unsigned char magic[2]; + + if (argc == 1) { + rpm_fd = STDIN_FILENO; + } else { + rpm_fd = xopen(argv[1], O_RDONLY); + } + + xread(rpm_fd, &lead, sizeof(struct rpm_lead)); + if (strncmp((char *) &lead.magic, RPM_MAGIC, 4) != 0) { + bb_error_msg_and_die("invalid RPM magic"); /* Just check the magic, the rest is irrelevant */ + } + + /* Skip the signature header */ + skip_header(rpm_fd); + lseek(rpm_fd, (8 - (lseek(rpm_fd, 0, SEEK_CUR) % 8)) % 8, SEEK_CUR); + + /* Skip the main header */ + skip_header(rpm_fd); + + xread(rpm_fd, &magic, 2); + if ((magic[0] != 0x1f) || (magic[1] != 0x8b)) { + bb_error_msg_and_die("invalid gzip magic"); + } + + if (unpack_gz_stream(rpm_fd, STDOUT_FILENO) < 0) { + bb_error_msg("error inflating"); + } + + close(rpm_fd); + + return 0; +} |