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authorGlenn L McGrath2001-06-20 07:48:00 +0000
committerGlenn L McGrath2001-06-20 07:48:00 +0000
commiteb1c94078f35d1b6e48741122c8bb9426befc5eb (patch)
tree48535c1f250f98707e595cfb83f47c83332c4fc9 /libbb/unarchive.c
parentb4a26e6fc09e9dd14ca206f8d9ed2c6e8976df1b (diff)
downloadbusybox-eb1c94078f35d1b6e48741122c8bb9426befc5eb.zip
busybox-eb1c94078f35d1b6e48741122c8bb9426befc5eb.tar.gz
Reorganise unarchiving functions, more code re-use, only does single pass(no more linked lists), basis for supporting a cpio (and cheaper untar) applet, but cpio applet isnt included in this.
It effects ar, dpkg-deb applets only
Diffstat (limited to 'libbb/unarchive.c')
-rw-r--r--libbb/unarchive.c500
1 files changed, 500 insertions, 0 deletions
diff --git a/libbb/unarchive.c b/libbb/unarchive.c
new file mode 100644
index 0000000..a0cc28e
--- /dev/null
+++ b/libbb/unarchive.c
@@ -0,0 +1,500 @@
+/*
+ * Copyright (C) 2000 by Glenn McGrath
+ * Copyright (C) 2001 by Laurence Anderson
+ *
+ * Based on previous work by busybox developers and others.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <utime.h>
+#include "libbb.h"
+
+typedef struct file_headers_s {
+ char *name;
+ char *link_name;
+ off_t size;
+ uid_t uid;
+ gid_t gid;
+ mode_t mode;
+ time_t mtime;
+ dev_t device;
+} file_header_t;
+
+off_t archive_offset;
+
+void seek_sub_file(FILE *src_stream, const int count)
+{
+ int i;
+ /* Try to fseek as faster */
+ archive_offset += count;
+ if (fseek(src_stream, count, SEEK_CUR) != 0 && errno == ESPIPE) {
+ for (i = 0; i < count; i++) {
+ fgetc(src_stream);
+ }
+ }
+ return;
+}
+
+
+/* Extract the data postioned at src_stream to either filesystem, stdout or
+ * buffer depending on the value of 'function' which is defined in libbb.h
+ *
+ * prefix doesnt have to be just a directory, it may prefix the filename as well.
+ *
+ * e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
+ * '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
+ * 'dpkg.' as their prefix
+ *
+ * For this reason if prefix does point to a dir then it must end with a
+ * trailing '/' or else the last dir will be assumed to be the file prefix
+ */
+char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
+ const int function, const char *prefix)
+{
+ FILE *dst_stream = NULL;
+ char *full_name = NULL;
+ char *buffer = NULL;
+ struct utimbuf t;
+
+ /* prefix doesnt have to be a proper path it may prepend
+ * the filename as well */
+ if (prefix != NULL) {
+ /* strip leading '/' in filename to extract as prefix may not be dir */
+ /* Cant use concat_path_file here as prefix might not be a directory */
+ char *path = file_entry->name;
+ if (*path == '/') {
+ path++;
+ }
+ full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
+ strcpy(full_name, prefix);
+ strcat(full_name, path);
+ } else {
+ full_name = file_entry->name;
+ }
+
+ if (function & extract_to_stdout) {
+ if (S_ISREG(file_entry->mode)) {
+ copy_file_chunk(src_stream, out_stream, file_entry->size);
+ archive_offset += file_entry->size;
+ }
+ }
+ else if (function & extract_one_to_buffer) {
+ if (S_ISREG(file_entry->mode)) {
+ buffer = (char *) xmalloc(file_entry->size + 1);
+ fread(buffer, 1, file_entry->size, src_stream);
+ archive_offset += file_entry->size;
+ return(buffer);
+ }
+ }
+ else if (function & extract_all_to_fs) {
+#if 0
+ struct stat oldfile;
+ if ( (S_ISLNK(file_entry->mode) ? lstat (full_name, &oldfile) : stat (full_name, &oldfile)) == 0) { /* The file already exists */
+ if (function & extract_unconditional || oldfile.st_mtime < file_entry->mtime) {
+ if (!S_ISDIR(oldfile.st_mode)) {
+ unlink(full_name); /* Directories might not be empty etc */
+ }
+ } else {
+ error_msg("%s not created: newer or same age file exists", file_entry->name);
+ if (S_ISREG(file_entry->mode)) {
+ seek_sub_file(src_stream, file_entry->size);
+ }
+ return (NULL);
+ }
+ }
+#endif
+ switch(file_entry->mode & S_IFMT) {
+ case S_IFREG:
+ if (file_entry->link_name) { /* Found a cpio hard link */
+ if (link(file_entry->link_name, full_name) != 0) {
+ perror_msg("Cannot link from %s to '%s'",
+ file_entry->name, file_entry->link_name);
+ }
+ } else {
+ if ((dst_stream = wfopen(full_name, "w")) == NULL) {
+ seek_sub_file(src_stream, file_entry->size);
+ return NULL;
+ }
+ archive_offset += file_entry->size;
+ copy_file_chunk(src_stream, dst_stream, file_entry->size);
+ fclose(dst_stream);
+ }
+ break;
+ case S_IFDIR:
+ /* Use create_path instead of mkdir incase prefix path
+ * hasnt been created */
+ if (function & extract_create_dirs) {
+ if (create_path(full_name, file_entry->mode) == FALSE) {
+ return NULL;
+ }
+ }
+ break;
+ case S_IFLNK:
+ if (symlink(file_entry->link_name, full_name) < 0) {
+ perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
+ return NULL;
+ }
+ break;
+ case S_IFSOCK:
+ case S_IFBLK:
+ case S_IFCHR:
+ case S_IFIFO:
+ if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
+ perror_msg("Cannot create node %s", file_entry->name);
+ return NULL;
+ }
+ break;
+ }
+ if (function & extract_preserve_date) {
+ t.actime = file_entry->mtime;
+ t.modtime = file_entry->mtime;
+ utime(full_name, &t);
+ }
+ chmod(full_name, file_entry->mode);
+ lchown(full_name, file_entry->uid, file_entry->gid);
+ } else {
+ /* If we arent extracting data we have to skip it,
+ * if data size is 0 then then just do it anyway
+ * (saves testing for it) */
+ seek_sub_file(src_stream, file_entry->size);
+ }
+
+ /* extract_list and extract_verbose_list can be used in conjunction
+ * with one of the above four extraction functions, so do this seperately */
+ if (function & extract_verbose_list) {
+ fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
+ file_entry->uid, file_entry->gid,
+ (int) file_entry->size, time_string(file_entry->mtime));
+ }
+ if ((function & extract_list) || (function & extract_verbose_list)){
+ /* fputs doesnt add a trailing \n, so use fprintf */
+ fprintf(out_stream, "%s\n", file_entry->name);
+ }
+
+ free(full_name);
+
+ return(NULL); /* Maybe we should say if failed */
+}
+
+#if defined BB_AR || defined BB_CPIO || defined BB_UNTAR
+char *unarchive(FILE *src_stream, void *(*get_headers)(FILE *),
+ const int extract_function, const char *prefix, char **extract_names)
+{
+ file_header_t *file_entry;
+ int found;
+ int i;
+ char *buffer = NULL;
+
+ archive_offset = 0;
+ while ((file_entry = (file_header_t *) get_headers(src_stream)) != NULL) {
+ found = FALSE;
+ if (extract_names[0] != NULL) {
+ for(i = 0; extract_names[i] != 0; i++) {
+ if (strcmp(extract_names[i], file_entry->name) == 0) {
+ found = TRUE;
+ }
+ }
+ if (!found) {
+ /* seek past the data entry */
+ if (!S_ISLNK(file_entry->mode) && file_entry->link_name && file_entry->size == 0) {
+ error_msg("You should extract %s as other files are hardlinked to it", file_entry->name);
+ }
+ seek_sub_file(src_stream, file_entry->size);
+ continue;
+ }
+ }
+ buffer = extract_archive(src_stream, stdout, file_entry, extract_function, prefix);
+ }
+ return(buffer);
+}
+#endif
+
+#if defined BB_AR || defined BB_DPKG_DEB || defined BB_DPKG
+void *get_header_ar(FILE *src_stream)
+{
+ file_header_t *typed;
+ 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];
+ } formated;
+ } ar;
+ static char *ar_long_names;
+
+ if (fread(ar.raw, 1, 60, src_stream) != 60) {
+ return(NULL);
+ }
+ archive_offset += 60;
+ /* align the headers based on the header magic */
+ if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
+ /* some version of ar, have an extra '\n' after each data entry,
+ * this puts the next header out by 1 */
+ if (ar.formated.magic[1] != '`') {
+ error_msg("Invalid magic");
+ return(NULL);
+ }
+ /* read the next char out of what would be the data section,
+ * if its a '\n' then it is a valid header offset by 1*/
+ archive_offset++;
+ if (fgetc(src_stream) != '\n') {
+ error_msg("Invalid magic");
+ return(NULL);
+ }
+ /* fix up the header, we started reading 1 byte too early */
+ /* raw_header[60] wont be '\n' as it should, but it doesnt matter */
+ memmove(ar.raw, &ar.raw[1], 59);
+ }
+
+ typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));
+
+ typed->size = (size_t) atoi(ar.formated.size);
+ /* long filenames have '/' as the first character */
+ if (ar.formated.name[0] == '/') {
+ if (ar.formated.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_names = (char *) xrealloc(ar_long_names, typed->size);
+ fread(ar_long_names, 1, typed->size, src_stream);
+ archive_offset += typed->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(NULL);
+ } else {
+ /* The number after the '/' indicates the offset in the ar data section
+ (saved in variable long_name) that conatains the real filename */
+ if (!ar_long_names) {
+ error_msg("Cannot resolve long file name");
+ return (NULL);
+ }
+ typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
+ }
+ } else {
+ /* short filenames */
+ typed->name = xcalloc(1, 16);
+ strncpy(typed->name, ar.formated.name, 16);
+ }
+ typed->name[strcspn(typed->name, " /")]='\0';
+
+ /* convert the rest of the now valid char header to its typed struct */
+ parse_mode(ar.formated.mode, &typed->mode);
+ typed->mtime = atoi(ar.formated.date);
+ typed->uid = atoi(ar.formated.uid);
+ typed->gid = atoi(ar.formated.gid);
+
+ return(typed);
+}
+#endif
+
+#if defined BB_CPIO
+void *get_header_cpio(FILE *src_stream)
+{
+ file_header_t *cpio_entry = NULL;
+ char cpio_header[110];
+ char dummy[14];
+ int namesize;
+ int major, minor, nlink;
+
+ /* There can be padding before archive header */
+ seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
+ if (fread(cpio_header, 1, 110, src_stream) == 110) {
+ archive_offset += 110;
+ if (strncmp(cpio_header, "07070", 5) != 0) {
+ error_msg("Unsupported format or invalid magic");
+ return(NULL);
+ }
+ switch (cpio_header[5]) {
+ case '2': /* "crc" header format */
+ /* Doesnt do the crc check yet */
+ case '1': /* "newc" header format */
+ cpio_entry = (file_header_t *) xcalloc(1, sizeof(file_header_t));
+ sscanf(cpio_header, "%14c%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
+ dummy, &cpio_entry->mode, &cpio_entry->uid, &cpio_entry->gid,
+ &nlink, &cpio_entry->mtime, &cpio_entry->size,
+ dummy, &major, &minor, &namesize, dummy);
+
+ cpio_entry->name = (char *) xcalloc(1, namesize);
+ fread(cpio_entry->name, 1, namesize, src_stream); /* Read in filename */
+ archive_offset += namesize;
+ /* Skip padding before file contents */
+ seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
+ if (strcmp(cpio_entry->name, "TRAILER!!!") == 0) {
+ printf("%d blocks\n", (int) (archive_offset % 512 ? (archive_offset / 512) + 1 : archive_offset / 512)); /* Always round up */
+ return(NULL);
+ }
+
+ if (S_ISLNK(cpio_entry->mode)) {
+ cpio_entry->link_name = (char *) xcalloc(1, cpio_entry->size + 1);
+ fread(cpio_entry->link_name, 1, cpio_entry->size, src_stream);
+ archive_offset += cpio_entry->size;
+ }
+ if (nlink > 1 && !S_ISDIR(cpio_entry->mode) && cpio_entry->size == 0) {
+ error_msg("%s not extracted: Cannot handle hard links yet", cpio_entry->name);
+ return(get_header_cpio(src_stream)); /* Recurse to next file */
+ }
+ cpio_entry->device = (major << 8) | minor;
+ break;
+ default:
+ error_msg("Unsupported format");
+ return(NULL);
+ }
+ if (ferror(src_stream) || feof(src_stream)) {
+ perror_msg("Stream error");
+ return(NULL);
+ }
+ }
+ return(cpio_entry);
+}
+#endif
+
+#if defined BB_UNTAR || defined BB_DPKG_DEB || defined BB_DPKG
+void *get_header_tar(FILE *tar_stream)
+{
+ union {
+ unsigned char raw[512];
+ struct {
+ char name[100]; /* 0-99 */
+ char mode[8]; /* 100-107 */
+ char uid[8]; /* 108-115 */
+ char gid[8]; /* 116-123 */
+ char size[12]; /* 124-135 */
+ char mtime[12]; /* 136-147 */
+ char chksum[8]; /* 148-155 */
+ char typeflag; /* 156-156 */
+ char linkname[100]; /* 157-256 */
+ char magic[6]; /* 257-262 */
+ char version[2]; /* 263-264 */
+ char uname[32]; /* 265-296 */
+ char gname[32]; /* 297-328 */
+ char devmajor[8]; /* 329-336 */
+ char devminor[8]; /* 337-344 */
+ char prefix[155]; /* 345-499 */
+ char padding[12]; /* 500-512 */
+ } formated;
+ } tar;
+ file_header_t *tar_entry = NULL;
+ long i;
+ long sum = 0;
+
+ if (archive_offset % 512 != 0) {
+ seek_sub_file(tar_stream, 512 - (archive_offset % 512));
+ }
+
+ if (fread(tar.raw, 1, 512, tar_stream) != 512) {
+ error_msg("Couldnt read header");
+ return(NULL);
+ }
+ archive_offset += 512;
+
+ /* Check header has valid magic, unfortunately some tar files
+ * have empty (0'ed) tar entries at the end, which will
+ * cause this to fail, so fail silently for now
+ */
+ if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
+ return(NULL);
+ }
+
+ /* Do checksum on headers */
+ for (i = 0; i < 148 ; i++) {
+ sum += tar.raw[i];
+ }
+ sum += ' ' * 8;
+ for (i = 156; i < 512 ; i++) {
+ sum += tar.raw[i];
+ }
+ if (sum != strtol(tar.formated.chksum, NULL, 8)) {
+ error_msg("Invalid tar header checksum");
+ return(NULL);
+ }
+
+ /* convert to type'ed variables */
+ tar_entry = xcalloc(1, sizeof(file_header_t));
+ tar_entry->name = xstrdup(tar.formated.name);
+
+ parse_mode(tar.formated.mode, &tar_entry->mode);
+ tar_entry->uid = strtol(tar.formated.uid, NULL, 8);
+ tar_entry->gid = strtol(tar.formated.gid, NULL, 8);
+ tar_entry->size = strtol(tar.formated.size, NULL, 8);
+ tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
+ tar_entry->link_name = strlen(tar.formated.linkname) ? xstrdup(tar.formated.linkname) : NULL;
+ tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
+ strtol(tar.formated.devminor, NULL, 8);
+
+ return(tar_entry);
+}
+#endif
+
+#if defined BB_DPKG || defined BB_DPKG_DEB
+char *deb_extract(const char *package_filename, FILE *out_stream, const int extract_function,
+ const char *prefix, const char *filename)
+{
+ FILE *deb_stream;
+ FILE *uncompressed_stream = NULL;
+ file_header_t *ar_header = NULL;
+ char *output_buffer = NULL;
+ char *ared_file = NULL;
+ char ar_magic[8];
+ char **file_list;
+ int gunzip_pid;
+
+ file_list = malloc(sizeof(char *));
+ file_list[0] = xstrdup(filename);
+ file_list[1] = NULL;
+
+ if (extract_function & extract_control_tar_gz) {
+ ared_file = xstrdup("control.tar.gz");
+ }
+ else if (extract_function & extract_data_tar_gz) {
+ ared_file = xstrdup("data.tar.gz");
+ }
+
+ /* open the debian package to be worked on */
+ deb_stream = wfopen(package_filename, "r");
+
+ /* check ar magic */
+ fread(ar_magic, 1, 8, deb_stream);
+ if (strncmp(ar_magic,"!<arch>",7) != 0) {
+ error_msg_and_die("invalid magic");
+ }
+ archive_offset = 8;
+
+ while ((ar_header = get_header_ar(deb_stream)) != NULL) {
+ if (strcmp(ared_file, ar_header->name) == 0) {
+ /* open a stream of decompressed data */
+ uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
+ archive_offset = 0;
+ output_buffer = unarchive(uncompressed_stream, get_header_tar, extract_function, prefix, file_list);
+ }
+ seek_sub_file(deb_stream, ar_header->size);
+ }
+ gz_close(gunzip_pid);
+ fclose(deb_stream);
+ fclose(uncompressed_stream);
+ free(ared_file);
+ return(output_buffer);
+}
+#endif