145 lines
4.4 KiB
C
145 lines
4.4 KiB
C
/* vi: set sw=4 ts=4: */
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/* Copyright 2001 Glenn McGrath.
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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#include "libbb.h"
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#include "bb_archive.h"
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#include "ar.h"
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/* WARNING: Clobbers str[len], so fields must be read in reverse order! */
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static unsigned read_num(char *str, int base, int len)
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{
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int err;
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/* ar fields are fixed length text strings (padded with spaces).
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* Ensure bb_strtou doesn't read past the field in case the full
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* width is used. */
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str[len] = 0;
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/* This code works because
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* on misformatted numbers bb_strtou returns all-ones */
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err = bb_strtou(str, NULL, base);
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if (err == -1)
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bb_error_msg_and_die("invalid ar header");
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return err;
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}
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char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
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{
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file_header_t *typed = archive_handle->file_header;
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unsigned size;
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union {
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char raw[60];
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struct ar_header formatted;
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} ar;
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#if ENABLE_FEATURE_AR_LONG_FILENAMES
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static char *ar_long_names;
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static unsigned ar_long_name_size;
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#endif
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/* dont use xread as we want to handle the error ourself */
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if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
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/* End Of File */
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return EXIT_FAILURE;
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}
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/* ar header starts on an even byte (2 byte aligned)
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* '\n' is used for padding
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*/
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if (ar.raw[0] == '\n') {
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/* fix up the header, we started reading 1 byte too early */
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memmove(ar.raw, &ar.raw[1], 59);
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ar.raw[59] = xread_char(archive_handle->src_fd);
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archive_handle->offset++;
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}
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archive_handle->offset += 60;
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if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
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bb_error_msg_and_die("invalid ar header");
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/*
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* Note that the fields MUST be read in reverse order as
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* read_num() clobbers the next byte after the field!
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* Order is: name, date, uid, gid, mode, size, magic.
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*/
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typed->size = size = read_num(ar.formatted.size, 10,
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sizeof(ar.formatted.size));
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/* special filenames have '/' as the first character */
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if (ar.formatted.name[0] == '/') {
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if (ar.formatted.name[1] == ' ') {
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/* This is the index of symbols in the file for compilers */
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data_skip(archive_handle);
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archive_handle->offset += size;
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return get_header_ar(archive_handle); /* Return next header */
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}
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#if ENABLE_FEATURE_AR_LONG_FILENAMES
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if (ar.formatted.name[1] == '/') {
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/* If the second char is a '/' then this entries data section
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* stores long filename for multiple entries, they are stored
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* in static variable long_names for use in future entries
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*/
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ar_long_name_size = size;
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free(ar_long_names);
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ar_long_names = xmalloc(size);
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xread(archive_handle->src_fd, ar_long_names, size);
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archive_handle->offset += size;
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/* Return next header */
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return get_header_ar(archive_handle);
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}
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#else
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bb_error_msg_and_die("long filenames not supported");
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#endif
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}
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/* Only size is always present, the rest may be missing in
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* long filename pseudo file. Thus we decode the rest
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* after dealing with long filename pseudo file.
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*/
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typed->mode = read_num(ar.formatted.mode, 8, sizeof(ar.formatted.mode));
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typed->gid = read_num(ar.formatted.gid, 10, sizeof(ar.formatted.gid));
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typed->uid = read_num(ar.formatted.uid, 10, sizeof(ar.formatted.uid));
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typed->mtime = read_num(ar.formatted.date, 10, sizeof(ar.formatted.date));
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#if ENABLE_FEATURE_AR_LONG_FILENAMES
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if (ar.formatted.name[0] == '/') {
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unsigned long_offset;
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/* The number after the '/' indicates the offset in the ar data section
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* (saved in ar_long_names) that conatains the real filename */
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long_offset = read_num(&ar.formatted.name[1], 10,
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sizeof(ar.formatted.name) - 1);
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if (long_offset >= ar_long_name_size) {
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bb_error_msg_and_die("can't resolve long filename");
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}
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typed->name = xstrdup(ar_long_names + long_offset);
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} else
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#endif
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{
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/* short filenames */
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typed->name = xstrndup(ar.formatted.name, 16);
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}
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typed->name[strcspn(typed->name, " /")] = '\0';
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if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
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archive_handle->action_header(typed);
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#if ENABLE_DPKG || ENABLE_DPKG_DEB
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if (archive_handle->dpkg__sub_archive) {
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while (archive_handle->dpkg__action_data_subarchive(archive_handle->dpkg__sub_archive) == EXIT_SUCCESS)
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continue;
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} else
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#endif
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archive_handle->action_data(archive_handle);
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} else {
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data_skip(archive_handle);
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}
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archive_handle->offset += typed->size;
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/* Set the file pointer to the correct spot, we may have been reading a compressed file */
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lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
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return EXIT_SUCCESS;
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}
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