diff options
Diffstat (limited to 'archival/libunarchive/get_header_cpio.c')
| -rw-r--r-- | archival/libunarchive/get_header_cpio.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/archival/libunarchive/get_header_cpio.c b/archival/libunarchive/get_header_cpio.c new file mode 100644 index 0000000..a2136e4 --- /dev/null +++ b/archival/libunarchive/get_header_cpio.c @@ -0,0 +1,136 @@ +/* + * 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 <stdlib.h> +#include <string.h> +#include "unarchive.h" +#include "libbb.h" + +struct hardlinks { + file_header_t *entry; + int inode; + struct hardlinks *next; +}; + +file_header_t *get_header_cpio(FILE *src_stream) +{ + file_header_t *cpio_entry = NULL; + char cpio_header[110]; + int namesize; + char dummy[16]; + int major, minor, nlink, inode; + static struct hardlinks *saved_hardlinks = NULL; + static int pending_hardlinks = 0; + + if (pending_hardlinks) { /* Deal with any pending hardlinks */ + struct hardlinks *tmp = saved_hardlinks, *oldtmp = NULL; + while (tmp) { + if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */ + cpio_entry = tmp->entry; + if (oldtmp) oldtmp->next = tmp->next; /* Remove item from linked list */ + else saved_hardlinks = tmp->next; + free(tmp); + return (cpio_entry); + } + oldtmp = tmp; + tmp = tmp->next; + } + pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */ + } + + /* 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, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c", + dummy, &inode, (unsigned int*)&cpio_entry->mode, + (unsigned int*)&cpio_entry->uid, (unsigned int*)&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 */ + if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */ + struct hardlinks *tmp = saved_hardlinks, *oldtmp = NULL; + while (tmp) { + error_msg("%s not created: cannot resolve hardlink", tmp->entry->name); + oldtmp = tmp; + tmp = tmp->next; + free (oldtmp->entry->name); + free (oldtmp->entry); + free (oldtmp); + } + saved_hardlinks = NULL; + pending_hardlinks = 0; + } + 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; + cpio_entry->size = 0; /* Stop possiable seeks in future */ + } + if (nlink > 1 && !S_ISDIR(cpio_entry->mode)) { + if (cpio_entry->size == 0) { /* Put file on a linked list for later */ + struct hardlinks *new = xmalloc(sizeof(struct hardlinks)); + new->next = saved_hardlinks; + new->inode = inode; + new->entry = cpio_entry; + saved_hardlinks = new; + return(get_header_cpio(src_stream)); /* Recurse to next file */ + } else { /* Found the file with data in */ + struct hardlinks *tmp = saved_hardlinks; + pending_hardlinks = 1; + while (tmp) { + if (tmp->inode == inode) { + tmp->entry->link_name = xstrdup(cpio_entry->name); + nlink--; + } + tmp = tmp->next; + } + if (nlink > 1) error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?"); + } + } + 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); +}
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