source: MondoRescue/branches/stable/mindi-busybox/archival/libunarchive/get_header_cpio.c@ 821

/* Copyright 2002 Laurence Anderson
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/sysmacros.h>     /* major() and minor() */
#include "unarchive.h"
#include "libbb.h"

typedef struct hardlinks_s {
    file_header_t *entry;
    int inode;
    struct hardlinks_s *next;
} hardlinks_t;

char get_header_cpio(archive_handle_t *archive_handle)
{
    static hardlinks_t *saved_hardlinks = NULL;
    static unsigned short pending_hardlinks = 0;
    file_header_t *file_header = archive_handle->file_header;
    char cpio_header[110];
    int namesize;
    char dummy[16];
    int major, minor, nlink, inode;

    if (pending_hardlinks) { /* Deal with any pending hardlinks */
        hardlinks_t *tmp;
        hardlinks_t *oldtmp;

        tmp = saved_hardlinks;
        oldtmp = NULL;

        while (tmp) {
            bb_error_msg_and_die("need to fix this\n");
            if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
                file_header = tmp->entry;
                if (oldtmp) {
                    oldtmp->next = tmp->next; /* Remove item from linked list */
                } else {
                    saved_hardlinks = tmp->next;
                }
                free(tmp);
                continue;
            }
            oldtmp = tmp;
            tmp = tmp->next;
        }
        pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
    }

    /* There can be padding before archive header */
    data_align(archive_handle, 4);

    if (archive_xread_all_eof(archive_handle, (unsigned char*)cpio_header, 110) == 0) {
        return(EXIT_FAILURE);
    }
    archive_handle->offset += 110;

    if ((strncmp(&cpio_header[0], "07070", 5) != 0) || ((cpio_header[5] != '1') && (cpio_header[5] != '2'))) {
        bb_error_msg_and_die("Unsupported cpio format, use newc or crc");
    }

    {
        unsigned long tmpsize;
        sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
            dummy, &inode, (unsigned int*)&file_header->mode,
            (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
            &nlink, &file_header->mtime, &tmpsize,
            dummy, &major, &minor, &namesize, dummy);
        file_header->size = tmpsize;
    }

    file_header->name = (char *) xzalloc(namesize + 1);
    archive_xread_all(archive_handle, file_header->name, namesize); /* Read in filename */
    archive_handle->offset += namesize;

    /* Update offset amount and skip padding before file contents */
    data_align(archive_handle, 4);

    if (strcmp(file_header->name, "TRAILER!!!") == 0) {
        printf("%d blocks\n", (int) (archive_handle->offset % 512 ? (archive_handle->offset / 512) + 1 : archive_handle->offset / 512)); /* Always round up */
        if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
            hardlinks_t *tmp = saved_hardlinks;
            hardlinks_t *oldtmp = NULL;
            while (tmp) {
                bb_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(EXIT_FAILURE);
    }

    if (S_ISLNK(file_header->mode)) {
        file_header->link_name = (char *) xzalloc(file_header->size + 1);
        archive_xread_all(archive_handle, file_header->link_name, file_header->size);
        archive_handle->offset += file_header->size;
        file_header->size = 0; /* Stop possible seeks in future */
    } else {
        file_header->link_name = NULL;
    }
    if (nlink > 1 && !S_ISDIR(file_header->mode)) {
        if (file_header->size == 0) { /* Put file on a linked list for later */
            hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
            new->next = saved_hardlinks;
            new->inode = inode;
            new->entry = file_header;
            saved_hardlinks = new;
            return(EXIT_SUCCESS); // Skip this one
        } else { /* Found the file with data in */
            hardlinks_t *tmp = saved_hardlinks;
            pending_hardlinks = 1;
            while (tmp) {
                if (tmp->inode == inode) {
                    tmp->entry->link_name = bb_xstrdup(file_header->name);
                    nlink--;
                }
                tmp = tmp->next;
            }
            if (nlink > 1) {
                bb_error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
            }
        }
    }
    file_header->device = makedev(major, minor);

    if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
        archive_handle->action_data(archive_handle);
        archive_handle->action_header(archive_handle->file_header);
    } else {
        data_skip(archive_handle);
    }

    archive_handle->offset += file_header->size;

    free(file_header->link_name);

    return (EXIT_SUCCESS);
}