| /* |
| * 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. |
| * |
| * NOTE: This is used by deb_extract to avoid calling the whole tar applet. |
| * Its functionality should be merged with tar to avoid duplication |
| */ |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include "libbb.h" |
| |
| /* |
| * stdout can be redircted to FILE *output |
| * If const char *file_prefix isnt NULL is prepended to all the extracted filenames. |
| * The purpose of const char *argument depends on the value of const int untar_function |
| */ |
| |
| extern char *untar(FILE *src_tar_file, FILE *output, const int untar_function, |
| const char *argument, const char *file_prefix) |
| { |
| typedef struct raw_tar_header { |
| 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 */ |
| } raw_tar_header_t; |
| |
| raw_tar_header_t raw_tar_header; |
| unsigned char *temp = (unsigned char *) &raw_tar_header; |
| long i; |
| long next_header_offset = 0; |
| long uncompressed_count = 0; |
| size_t size; |
| mode_t mode; |
| |
| while (fread((char *) &raw_tar_header, 1, 512, src_tar_file) == 512) { |
| long sum = 0; |
| |
| if (ferror(src_tar_file) || feof(src_tar_file)) { |
| perror_msg("untar: "); |
| break; |
| } |
| |
| uncompressed_count += 512; |
| |
| /* Check header has valid magic */ |
| if (strncmp(raw_tar_header.magic, "ustar", 5) != 0) { |
| /* |
| * FIXME, Need HELP with this |
| * |
| * This has to fail silently or it incorrectly reports errors when called from |
| * deb_extract. |
| * The problem is deb_extract decompresses the .gz file in a child process and |
| * untar reads from the child proccess. The child process finishes and exits, |
| * but fread reads 0's from the src_tar_file even though the child |
| * closed its handle. |
| */ |
| // error_msg("Invalid tar magic"); |
| break; |
| } |
| |
| /* Do checksum on headers */ |
| for (i = 0; i < 148 ; i++) { |
| sum += temp[i]; |
| } |
| sum += ' ' * 8; |
| for (i = 156; i < 512 ; i++) { |
| sum += temp[i]; |
| } |
| if (sum != strtol(raw_tar_header.chksum, NULL, 8)) { |
| error_msg("Invalid tar header checksum"); |
| break; |
| } |
| |
| /* convert to type'ed variables */ |
| size = strtol(raw_tar_header.size, NULL, 8); |
| parse_mode(raw_tar_header.mode, &mode); |
| |
| /* start of next header is at */ |
| next_header_offset = uncompressed_count + size; |
| if (size % 512 != 0) { |
| next_header_offset += (512 - size % 512); |
| } |
| |
| /* If an exclude list is specified check current file against list */ |
| #if 0 |
| if (*exclude_list != NULL) { |
| i = 0; |
| while (exclude_list[i] != 0) { |
| if (strncmp(exclude_list[i], raw_tar_header.name, strlen(raw_tar_header.name)) == 0) { |
| break; |
| } |
| i++; |
| } |
| if (exclude_list[i] != 0) { |
| continue; |
| } |
| } |
| #endif |
| if (untar_function & (extract_contents | extract_verbose_extract | extract_contents_to_file)) { |
| fprintf(output, "%s\n", raw_tar_header.name); |
| } |
| |
| switch (raw_tar_header.typeflag ) { |
| case '0': |
| case '\0': { |
| /* If the name ends in a '/' then assume it is |
| * supposed to be a directory, and fall through |
| */ |
| int name_length = strlen(raw_tar_header.name); |
| if (raw_tar_header.name[name_length - 1] != '/') { |
| switch (untar_function) { |
| case (extract_extract): |
| case (extract_verbose_extract): |
| case (extract_control): { |
| FILE *dst_file = NULL; |
| char *full_name; |
| |
| if (file_prefix != NULL) { |
| full_name = xmalloc(strlen(argument) + strlen(file_prefix) + name_length + 3); |
| sprintf(full_name, "%s/%s.%s", argument, file_prefix, strrchr(raw_tar_header.name, '/') + 1); |
| } else { |
| full_name = concat_path_file(argument, raw_tar_header.name); |
| } |
| dst_file = wfopen(full_name, "w"); |
| copy_file_chunk(src_tar_file, dst_file, (unsigned long long) size); |
| uncompressed_count += size; |
| fclose(dst_file); |
| chmod(full_name, mode); |
| free(full_name); |
| } |
| break; |
| case (extract_info): |
| if (strstr(raw_tar_header.name, argument) != NULL) { |
| copy_file_chunk(src_tar_file, stdout, (unsigned long long) size); |
| uncompressed_count += size; |
| } |
| break; |
| case (extract_field): |
| if (strstr(raw_tar_header.name, "./control") != NULL) { |
| return(read_text_file_to_buffer(src_tar_file)); |
| } |
| break; |
| } |
| break; |
| } |
| } |
| case '5': |
| if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) { |
| int ret; |
| char *dir; |
| dir = concat_path_file(argument, raw_tar_header.name); |
| ret = create_path(dir, mode); |
| free(dir); |
| if (ret == FALSE) { |
| perror_msg("%s: Cannot mkdir", raw_tar_header.name); |
| return NULL; |
| } |
| chmod(dir, mode); |
| } |
| break; |
| case '1': |
| if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) { |
| if (link(raw_tar_header.linkname, raw_tar_header.name) < 0) { |
| perror_msg("%s: Cannot create hard link to '%s'", raw_tar_header.name, raw_tar_header.linkname); |
| return NULL; |
| } |
| } |
| break; |
| case '2': |
| if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) { |
| if (symlink(raw_tar_header.linkname, raw_tar_header.name) < 0) { |
| perror_msg("%s: Cannot create symlink to '%s'", raw_tar_header.name, raw_tar_header.linkname); |
| return NULL; |
| } |
| } |
| break; |
| case '3': |
| case '4': |
| case '6': |
| // if (tarExtractSpecial( &header, extractFlag, tostdoutFlag)==FALSE) |
| // errorFlag=TRUE; |
| // break; |
| default: |
| error_msg("Unknown file type '%c' in tar file", raw_tar_header.typeflag); |
| return NULL; |
| } |
| /* |
| * Seek to start of next block, cant use fseek as unzip() does support it |
| */ |
| while (uncompressed_count < next_header_offset) { |
| if (fgetc(src_tar_file) == EOF) { |
| break; |
| } |
| uncompressed_count++; |
| } |
| } |
| return NULL; |
| } |