*: introduce and use FAST_FUNC: regparm on i386, otherwise no-on
[oweals/busybox.git] / archival / libunarchive / get_header_cpio.c
index e0272003c81dc55ed2bbf210f3ac033f95dbd30b..4ed18c68f3eac7009e16fa192afd9518530d062a 100644 (file)
@@ -8,69 +8,32 @@
 #include "unarchive.h"
 
 typedef struct hardlinks_s {
-       char *name;
-       int inode;
        struct hardlinks_s *next;
+       int inode; /* TODO: must match maj/min too! */
+       int mode ;
+       int mtime; /* These three are useful only in corner case */
+       int uid  ; /* of hardlinks with zero size body */
+       int gid  ;
+       char name[1];
 } hardlinks_t;
 
-char get_header_cpio(archive_handle_t *archive_handle)
+char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle)
 {
        static hardlinks_t *saved_hardlinks = NULL;
-       static unsigned short pending_hardlinks = 0;
-       static int inode;
+       static hardlinks_t *saved_hardlinks_created = NULL;
+
        file_header_t *file_header = archive_handle->file_header;
        char cpio_header[110];
-       int namesize;
        char dummy[16];
-       int major, minor, nlink;
-
-       if (pending_hardlinks) { /* Deal with any pending hardlinks */
-               hardlinks_t *tmp, *oldtmp;
-
-               tmp = saved_hardlinks;
-               oldtmp = NULL;
-
-               file_header->link_name = file_header->name;
-               file_header->size = 0;
-
-               while (tmp) {
-                       if (tmp->inode != inode) {
-                               tmp = tmp->next;
-                               continue;
-                       }
-
-                       file_header->name = tmp->name;
-
-                       if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
-                               archive_handle->action_data(archive_handle);
-                               archive_handle->action_header(archive_handle->file_header);
-                       }
-
-                       pending_hardlinks--;
-
-                       oldtmp = tmp;
-                       tmp = tmp->next;
-                       free(oldtmp->name);
-                       free(oldtmp);
-                       if (oldtmp == saved_hardlinks)
-                               saved_hardlinks = tmp;
-               }
-
-               file_header->name = file_header->link_name;
-
-               if (pending_hardlinks > 1) {
-                       bb_error_msg("error resolving hardlink: archive made by GNU cpio 2.0-2.2?");
-               }
-
-               /* No more pending hardlinks, read next file entry */
-               pending_hardlinks = 0;
-       }
+       int namesize;
+       int major, minor, nlink, mode, inode;
+       unsigned size, uid, gid, mtime;
 
        /* 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;
+               goto create_hardlinks;
        }
        archive_handle->offset += 110;
 
@@ -80,17 +43,19 @@ char get_header_cpio(archive_handle_t *archive_handle)
                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;
-       }
+       sscanf(cpio_header + 6,
+                       "%8x" "%8x" "%8x" "%8x"
+                       "%8x" "%8x" "%8x" /*maj,min:*/ "%16c"
+                       /*rmaj,rmin:*/"%8x" "%8x" "%8x" /*chksum:*/ "%8c",
+                       &inode, &mode, &uid, &gid,
+                       &nlink, &mtime, &size, dummy,
+                       &major, &minor, &namesize, dummy);
+       file_header->mode = mode;
+       file_header->uid = uid;
+       file_header->gid = gid;
+       file_header->mtime = mtime;
+       file_header->size = size;
 
-       free(file_header->name);
        file_header->name = xzalloc(namesize + 1);
        /* Read in filename */
        xread(archive_handle->src_fd, file_header->name, namesize);
@@ -100,61 +65,104 @@ char get_header_cpio(archive_handle_t *archive_handle)
        data_align(archive_handle, 4);
 
        if (strcmp(file_header->name, "TRAILER!!!") == 0) {
-               /* Always round up */
-               printf("%d blocks\n", (int) (archive_handle->offset % 512 ?
-                                            archive_handle->offset / 512 + 1 :
-                                             archive_handle->offset / 512
-                                           ));
-               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->name);
-                               oldtmp = tmp;
-                               tmp = tmp->next;
-                               free(oldtmp->name);
-                               free(oldtmp);
-                       }
-                       saved_hardlinks = NULL;
-                       pending_hardlinks = 0;
-               }
-               return EXIT_FAILURE;
+               /* Always round up. ">> 9" divides by 512 */
+               printf("%"OFF_FMT"u blocks\n", (archive_handle->offset + 511) >> 9);
+               goto create_hardlinks;
        }
 
        if (S_ISLNK(file_header->mode)) {
-               file_header->link_name = xzalloc(file_header->size + 1);
-               xread(archive_handle->src_fd, file_header->link_name, file_header->size);
+               file_header->link_target = xzalloc(file_header->size + 1);
+               xread(archive_handle->src_fd, file_header->link_target, file_header->size);
                archive_handle->offset += file_header->size;
                file_header->size = 0; /* Stop possible seeks in future */
        } else {
-               file_header->link_name = NULL;
+               file_header->link_target = 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));
+
+// TODO: data_extract_all can't deal with hardlinks to non-files...
+// (should be !S_ISDIR instead of S_ISREG here)
+
+       if (nlink > 1 && S_ISREG(file_header->mode)) {
+               hardlinks_t *new = xmalloc(sizeof(*new) + namesize);
+               new->inode = inode;
+               new->mode  = mode ;
+               new->mtime = mtime;
+               new->uid   = uid  ;
+               new->gid   = gid  ;
+               strcpy(new->name, file_header->name);
+               /* Put file on a linked list for later */
+               if (size == 0) {
                        new->next = saved_hardlinks;
-                       new->inode = inode;
-                       /* name current allocated, freed later */
-                       new->name = file_header->name;
-                       file_header->name = NULL;
                        saved_hardlinks = new;
                        return EXIT_SUCCESS; /* Skip this one */
+                       /* TODO: this breaks cpio -t (it does not show hardlinks) */
                }
-               /* Found the file with data in */
-               pending_hardlinks = nlink;
+               new->next = saved_hardlinks_created;
+               saved_hardlinks_created = new;
        }
        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);
+               archive_handle->action_header(file_header);
        } else {
                data_skip(archive_handle);
        }
 
        archive_handle->offset += file_header->size;
 
-       free(file_header->link_name);
+       free(file_header->link_target);
+       free(file_header->name);
+       file_header->link_target = NULL;
+       file_header->name = NULL;
 
        return EXIT_SUCCESS;
+
+ create_hardlinks:
+       free(file_header->link_target);
+       free(file_header->name);
+
+       while (saved_hardlinks) {
+               hardlinks_t *cur;
+               hardlinks_t *make_me = saved_hardlinks;
+               saved_hardlinks = make_me->next;
+
+               memset(file_header, 0, sizeof(*file_header));
+               file_header->name = make_me->name;
+               file_header->mode = make_me->mode;
+               /*file_header->size = 0;*/
+
+               /* Try to find a file we are hardlinked to */
+               cur = saved_hardlinks_created;
+               while (cur) {
+                       /* TODO: must match maj/min too! */
+                       if (cur->inode == make_me->inode) {
+                               file_header->link_target = cur->name;
+                                /* link_target != NULL, size = 0: "I am a hardlink" */
+                               if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
+                                       archive_handle->action_data(archive_handle);
+                               free(make_me);
+                               goto next_link;
+                       }
+               }
+               /* Oops... no file with such inode was created... do it now
+                * (happens when hardlinked files are empty (zero length)) */
+               file_header->mtime = make_me->mtime;
+               file_header->uid   = make_me->uid  ;
+               file_header->gid   = make_me->gid  ;
+               if (archive_handle->filter(archive_handle) == EXIT_SUCCESS)
+                       archive_handle->action_data(archive_handle);
+               /* Move to the list of created hardlinked files */
+               make_me->next = saved_hardlinks_created;
+               saved_hardlinks_created = make_me;
+ next_link: ;
+       }
+
+       while (saved_hardlinks_created) {
+               hardlinks_t *p = saved_hardlinks_created;
+               saved_hardlinks_created = p->next;
+               free(p);
+       }
+
+       return EXIT_FAILURE; /* "No more files to process" */
 }