/* * 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 #include #include #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; }