hush/archival/libunarchive/get_header_ar.c
2007-04-07 00:44:31 +00:00

127 lines
4.1 KiB
C

/* vi: set sw=4 ts=4: */
/* Copyright 2001 Glenn McGrath.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
char get_header_ar(archive_handle_t *archive_handle)
{
int err;
file_header_t *typed = archive_handle->file_header;
union {
char raw[60];
struct {
char name[16];
char date[12];
char uid[6];
char gid[6];
char mode[8];
char size[10];
char magic[2];
} formatted;
} ar;
#if ENABLE_FEATURE_AR_LONG_FILENAMES
static char *ar_long_names;
static unsigned ar_long_name_size;
#endif
/* dont use xread as we want to handle the error ourself */
if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
/* End Of File */
return EXIT_FAILURE;
}
/* ar header starts on an even byte (2 byte aligned)
* '\n' is used for padding
*/
if (ar.raw[0] == '\n') {
/* fix up the header, we started reading 1 byte too early */
memmove(ar.raw, &ar.raw[1], 59);
ar.raw[59] = xread_char(archive_handle->src_fd);
archive_handle->offset++;
}
archive_handle->offset += 60;
/* align the headers based on the header magic */
if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
bb_error_msg_and_die("invalid ar header");
/* FIXME: more thorough routine would be in order here */
/* (we have something like that in tar) */
/* but for now we are lax. This code works because */
/* on misformatted numbers bb_strtou returns all-ones */
typed->mode = err = bb_strtou(ar.formatted.mode, NULL, 8);
if (err == -1) bb_error_msg_and_die("invalid ar header");
typed->mtime = err = bb_strtou(ar.formatted.date, NULL, 10);
if (err == -1) bb_error_msg_and_die("invalid ar header");
typed->uid = err = bb_strtou(ar.formatted.uid, NULL, 10);
if (err == -1) bb_error_msg_and_die("invalid ar header");
typed->gid = err = bb_strtou(ar.formatted.gid, NULL, 10);
if (err == -1) bb_error_msg_and_die("invalid ar header");
typed->size = err = bb_strtou(ar.formatted.size, NULL, 10);
if (err == -1) bb_error_msg_and_die("invalid ar header");
/* long filenames have '/' as the first character */
if (ar.formatted.name[0] == '/') {
#if ENABLE_FEATURE_AR_LONG_FILENAMES
unsigned long_offset;
if (ar.formatted.name[1] == '/') {
/* If the second char is a '/' then this entries data section
* stores long filename for multiple entries, they are stored
* in static variable long_names for use in future entries */
ar_long_name_size = typed->size;
ar_long_names = xmalloc(ar_long_name_size);
xread(archive_handle->src_fd, ar_long_names, ar_long_name_size);
archive_handle->offset += ar_long_name_size;
/* This ar entries data section only contained filenames for other records
* they are stored in the static ar_long_names for future reference */
return get_header_ar(archive_handle); /* Return next header */
}
if (ar.formatted.name[1] == ' ') {
/* This is the index of symbols in the file for compilers */
data_skip(archive_handle);
archive_handle->offset += typed->size;
return get_header_ar(archive_handle); /* Return next header */
}
/* The number after the '/' indicates the offset in the ar data section
* (saved in variable long_name) that conatains the real filename */
long_offset = atoi(&ar.formatted.name[1]);
if (long_offset >= ar_long_name_size) {
bb_error_msg_and_die("can't resolve long filename");
}
typed->name = xstrdup(ar_long_names + long_offset);
#else
bb_error_msg_and_die("long filenames not supported");
#endif
} else {
/* short filenames */
typed->name = xstrndup(ar.formatted.name, 16);
}
typed->name[strcspn(typed->name, " /")] = '\0';
if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
archive_handle->action_header(typed);
if (archive_handle->sub_archive) {
while (archive_handle->action_data_subarchive(archive_handle->sub_archive) == EXIT_SUCCESS)
/* repeat */;
} else {
archive_handle->action_data(archive_handle);
}
} else {
data_skip(archive_handle);
}
archive_handle->offset += typed->size;
/* Set the file pointer to the correct spot, we may have been reading a compressed file */
lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
return EXIT_SUCCESS;
}