cpio applet, and changes to associated code

git-svn-id: svn://busybox.net/trunk/busybox@2887 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 70 insertions, 15 deletions

diff --git a/libbb/unarchive.c b/libbb/unarchive.c
index 635dcae35..20609ded7 100644
--- a/libbb/unarchive.c
+++ b/libbb/unarchive.c
@@ -119,10 +119,11 @@ char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *f
                 }
         }
         else if (function & extract_all_to_fs) {
-#if 0
                 struct stat oldfile;
-                if ( (S_ISLNK(file_entry->mode) ? lstat (full_name, &oldfile) : stat (full_name, &oldfile)) == 0) { /* The file already exists */
-                        if (function & extract_unconditional || oldfile.st_mtime < file_entry->mtime) {
+                int stat_res;
+                stat_res = lstat (full_name, &oldfile);
+                if (stat_res == 0) { /* The file already exists */
+                        if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
                                 if (!S_ISDIR(oldfile.st_mode)) {
                                         unlink(full_name); /* Directories might not be empty etc */
                                 }
@@ -134,7 +135,6 @@ char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *f
                                 return (NULL);
                         }
                 }
-#endif
                 switch(file_entry->mode & S_IFMT) {
                         case S_IFREG:
                                 if (file_entry->link_name) { /* Found a cpio hard link */
@@ -153,10 +153,11 @@ char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *f
                                 }
                                 break;
                         case S_IFDIR:
-                                /* Use make_directory instead of mkdir in case prefix path hasn't been created */
-                                if (function & extract_create_dirs) {
-                                        if (make_directory(full_name, file_entry->mode, FILEUTILS_RECUR) < 0) {
-                                                return NULL;
+                                if ((function & extract_create_dirs) && (stat_res != 0)) {
+                                        /* Make sure the prefix component of full_name was create
+                                         * in applet before getting here*/
+                                        if (mkdir(full_name, file_entry->mode) < 0) {
+                                                perror_msg("extract_archive: ");
                                         }
                                 }
                                 break;
@@ -335,14 +336,38 @@ void *get_header_ar(FILE *src_stream)
 #endif
 
 #ifdef L_get_header_cpio
+struct hardlinks {
+        file_header_t *entry;
+        int inode;
+        struct hardlinks *next;
+};
+
 void *get_header_cpio(FILE *src_stream)
 {
         file_header_t *cpio_entry = NULL;
         char cpio_header[110];
-        char dummy[14];
         int namesize;
-        int major, minor, nlink;
-
+        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) {
@@ -356,8 +381,8 @@ void *get_header_cpio(FILE *src_stream)
                                 /* 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, "%14c%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
-                                        dummy, &cpio_entry->mode, &cpio_entry->uid, &cpio_entry->gid,
+                                sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
+                                        dummy, &inode, &cpio_entry->mode, &cpio_entry->uid, &cpio_entry->gid,
                                         &nlink, &cpio_entry->mtime, &cpio_entry->size,
                                         dummy, &major, &minor, &namesize, dummy);
 
@@ -368,6 +393,19 @@ void *get_header_cpio(FILE *src_stream)
                                 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);
                                 }
 
@@ -376,9 +414,26 @@ void *get_header_cpio(FILE *src_stream)
                                         fread(cpio_entry->link_name, 1, cpio_entry->size, src_stream);
                                         archive_offset += cpio_entry->size;
                                 }
-                                if (nlink > 1 && !S_ISDIR(cpio_entry->mode) && cpio_entry->size == 0) {
-                                        error_msg("%s not extracted: Cannot handle hard links yet", cpio_entry->name);
+                                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;