This is primarily to allow deb_extract to be independent of the tar applet.

TODO: This function and its conterpart in tar.c should be merged

diff --git a/libbb/untar.c b/libbb/untar.c
new file mode 100644 (file)
index 0000000..1542e39
--- /dev/null
+++ b/libbb/untar.c
@@ -0,0 +1,200 @@
+/*
+ *  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"
+
+extern int untar(FILE *src_tar_file, int untar_function, char *base_path)
+{
+       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;
+
+//     const int dpkg_deb_contents = 1;
+//     const int dpkg_deb_control = 2;
+//     const int dpkg_deb_info = 4;
+       const int untar_extract = 8;
+//     const int dpkg_deb_verbose_extract = 16;
+//     const int dpkg_deb_list = 32;
+
+       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;
+
+//     signal(SIGCHLD, child_died);
+
+       while (fread((char *) &raw_tar_header, 1, 512, src_tar_file)==512) {
+               long sum = 0;
+               char *dir;
+
+               uncompressed_count += 512;
+
+               /* Check header has valid magic */
+               if (strncmp(raw_tar_header.magic, "ustar", 5) != 0) {
+                       /* Put this pack after TODO (check child still alive) is done */
+//                     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);
+               }
+
+               /*
+                * seek to start of control file, return length
+                *
+               if (dpkg_untar_function & dpkg_untar_seek_control) {
+                       if ((raw_tar_header.typeflag == '0') || (raw_tar_header.typeflag == '\0')) {
+                               char *tar_filename;
+
+                               tar_filename = strrchr(raw_tar_header.name, '/');
+                               if (tar_filename == NULL) {
+                                       tar_filename = strdup(raw_tar_header.name);
+                               } else {
+                                       tar_filename++;
+                               }
+
+                               if (strcmp(tar_filename, "control") == 0) {
+                                       return(size);
+                               }
+                       }
+
+               }
+*/
+               /* extract files */
+               dir = xmalloc(strlen(raw_tar_header.name) + strlen(base_path) + 2);
+
+               sprintf(dir, "%s/%s", base_path, raw_tar_header.name);
+               create_path(dir, 0777);
+               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
+                                */
+                               if (raw_tar_header.name[strlen(raw_tar_header.name)-1] != '/') {
+                                       if (untar_function & untar_extract) {
+                                               int out_count=0;
+                                               FILE *dst_file;
+       
+                                               dst_file = wfopen(dir, "w");
+                                               if (copy_file_chunk(src_tar_file, dst_file, size) == FALSE) {
+                                                       error_msg_and_die("Couldnt extract file");
+                                               }
+                                               uncompressed_count += out_count;
+                                               fclose(dst_file);
+                                               break;
+                                       }
+                               }
+                       case '5':
+                               if (untar_function & untar_extract) {
+                                       if (create_path(dir, mode) != TRUE) {
+                                               free(dir);
+                                               perror_msg("%s: Cannot mkdir", raw_tar_header.name); 
+                                               return(EXIT_FAILURE);
+                                       }
+                               }
+                               break;
+                       case '1':
+                               if (untar_function & untar_extract) {
+                                       if (link(raw_tar_header.linkname, raw_tar_header.name) < 0) {
+                                               free(dir);
+                                               perror_msg("%s: Cannot create hard link to '%s'", raw_tar_header.name, raw_tar_header.linkname); 
+                                               return(EXIT_FAILURE);
+                                       }
+                               }
+                               break;
+                       case '2':
+                               if (untar_function & untar_extract) {
+                                       if (symlink(raw_tar_header.linkname, raw_tar_header.name) < 0) {
+                                               free(dir);
+                                               perror_msg("%s: Cannot create symlink to '%s'", raw_tar_header.name, raw_tar_header.linkname); 
+                                               return(EXIT_FAILURE);
+                                       }
+                               }
+                               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);
+                               free(dir);
+                               return(EXIT_FAILURE);
+               }
+               free(dir);
+       }
+       /* skip to start of next header */
+       while(uncompressed_count < next_header_offset) {
+               char ch[2];
+               if (fread(ch, 1, 1, src_tar_file) != 1) {
+                       error_msg("read error\n");
+                       getchar();
+               } else {
+                       uncompressed_count++;
+               }
+       }
+               /* 
+                * TODO: Check that gunzip child hasnt finished
+                */
+       return(EXIT_SUCCESS);
+}