decompress_bunzip2: handle concatenated .bz2 files

[platform/upstream/busybox.git] / archival / libunarchive / decompress_bunzip2.c

diff --git a/archival/libunarchive/decompress_bunzip2.c b/archival/libunarchive/decompress_bunzip2.c
index 2201568..549c8b1 100644 (file)
--- a/archival/libunarchive/decompress_bunzip2.c
+++ b/archival/libunarchive/decompress_bunzip2.c
@@ -44,7 +44,7 @@
 #define RETVAL_LAST_BLOCK               (-1)
 #define RETVAL_NOT_BZIP_DATA            (-2)
 #define RETVAL_UNEXPECTED_INPUT_EOF     (-3)
-#define RETVAL_SHORT_WRITE              (-4)
+//#define RETVAL_SHORT_WRITE              (-4)
 #define RETVAL_DATA_ERROR               (-5)
 #define RETVAL_OUT_OF_MEMORY            (-6)
 #define RETVAL_OBSOLETE_INPUT           (-7)
@@ -584,8 +584,8 @@ int FAST_FUNC read_bunzip(bunzip_data *bd, char *outbuf, int len)
 /* Because bunzip2 is used for help text unpacking, and because bb_show_usage()
    should work for NOFORK applets too, we must be extremely careful to not leak
    any allocations! */
-int FAST_FUNC start_bunzip(bunzip_data **bdp, int in_fd, const unsigned char *inbuf,
-                                               int len)
+int FAST_FUNC start_bunzip(bunzip_data **bdp, int in_fd,
+               const void *inbuf, int len)
 {
        bunzip_data *bd;
        unsigned i;
@@ -606,9 +606,11 @@ int FAST_FUNC start_bunzip(bunzip_data **bdp, int in_fd, const unsigned char *in
        if (-1 == in_fd) {
                /* in this case, bd->inbuf is read-only */
                bd->inbuf = (void*)inbuf; /* cast away const-ness */
-               bd->inbufCount = len;
-       } else
+       } else {
                bd->inbuf = (unsigned char *)(bd + 1);
+               memcpy(bd->inbuf, inbuf, len);
+       }
+       bd->inbufCount = len;
 
        /* Init the CRC32 table (big endian) */
        crc32_filltable(bd->crc32Table, 1);
@@ -652,37 +654,59 @@ IF_DESKTOP(long long) int FAST_FUNC
 unpack_bz2_stream(int src_fd, int dst_fd)
 {
        IF_DESKTOP(long long total_written = 0;)
+               bunzip_data *bd;
        char *outbuf;
-       bunzip_data *bd;
        int i;
+       unsigned len;
 
        outbuf = xmalloc(IOBUF_SIZE);
-       i = start_bunzip(&bd, src_fd, NULL, 0);
-       if (!i) {
-               for (;;) {
-                       i = read_bunzip(bd, outbuf, IOBUF_SIZE);
-                       if (i <= 0) break;
-                       if (i != full_write(dst_fd, outbuf, i)) {
-                               i = RETVAL_SHORT_WRITE;
-                               break;
+       len = 0;
+       while (1) { /* "Process one BZ... stream" loop */
+
+               i = start_bunzip(&bd, src_fd, outbuf + 2, len);
+
+               if (i == 0) {
+                       while (1) { /* "Produce some output bytes" loop */
+                               i = read_bunzip(bd, outbuf, IOBUF_SIZE);
+                               if (i <= 0)
+                                       break;
+                               if (i != full_write(dst_fd, outbuf, i)) {
+                                       bb_error_msg("short write");
+                                       goto release_mem;
+                               }
+                               IF_DESKTOP(total_written += i;)
                        }
-                       IF_DESKTOP(total_written += i;)
                }
-       }
 
-       /* Check CRC and release memory */
-
-       if (i == RETVAL_LAST_BLOCK) {
+               if (i != RETVAL_LAST_BLOCK) {
+                       bb_error_msg("bunzip error %d", i);
+                       break;
+               }
                if (bd->headerCRC != bd->totalCRC) {
                        bb_error_msg("CRC error");
-               } else {
-                       i = RETVAL_OK;
+                       break;
                }
-       } else if (i == RETVAL_SHORT_WRITE) {
-               bb_error_msg("short write");
-       } else {
-               bb_error_msg("bunzip error %d", i);
+
+               /* Successfully unpacked one BZ stream */
+               i = RETVAL_OK;
+
+               /* Do we have "BZ..." after last processed byte?
+                * pbzip2 (parallelized bzip2) produces such files.
+                */
+               len = bd->inbufCount - bd->inbufPos;
+               memcpy(outbuf, &bd->inbuf[bd->inbufPos], len);
+               if (len < 2) {
+                       if (safe_read(src_fd, outbuf + len, 2 - len) != 2 - len)
+                               break;
+                       len = 2;
+               }
+               if (*(uint16_t*)outbuf != BZIP2_MAGIC) /* "BZ"? */
+                       break;
+               dealloc_bunzip(bd);
+               len -= 2;
        }
+
+ release_mem:
        dealloc_bunzip(bd);
        free(outbuf);