fecdec: Add another sanity check to find_group().
[paraslash.git] / fecdec_filter.c
index 30ac818..5f37f1a 100644 (file)
  */
 #define NUM_FEC_GROUPS 3
 
-/** Default size of the output buffer of the fecdec filter. */
-#define FECDEC_DEFAULT_OUTBUF_SIZE (16 * 1024)
-/** Maximal size of the output buffer of the fecdec filter. */
-#define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
+/** Size of the output buffer of the fecdec filter. */
+#define FECDEC_OUTBUF_SIZE (1024 * 1024) /* FIXME: This has to depend on the fec params */
 
 /** Data read from the header of a slice. */
 struct fec_header {
@@ -119,10 +117,15 @@ static int find_group(struct fec_header *h,
        FOR_EACH_FECDEC_GROUP(fg, pfd) {
                if (fg->h.group_num != h->group_num)
                        continue;
+               if (fg->num_received_slices == 0)
+                       goto success;
                if (fg->h.slices_per_group != h->slices_per_group)
-                       continue;
+                       return -E_BAD_FEC_HEADER;
                if (fg->h.data_slices_per_group != h->data_slices_per_group)
-                       continue;
+                       return -E_BAD_FEC_HEADER;
+               if (fg->h.group_bytes != h->group_bytes)
+                       return -E_BAD_FEC_HEADER;
+success:
                *result = fg;
                return 1;
        }
@@ -163,8 +166,8 @@ static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
        }
        if (!group_complete(oldest) && !group_empty(oldest))
                PARA_WARNING_LOG("Clearing incomplete group %d "
-                       "(contains %d slices)\n", fg->h.group_num,
-                       fg->num_received_slices);
+                       "(contains %d slices)\n", oldest->h.group_num,
+                       oldest->num_received_slices);
        clear_group(oldest);
        return oldest;
 }
@@ -253,7 +256,7 @@ static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
 {
        int i, ret, sb = fg->h.slice_bytes;
-       size_t written = 0, need;
+       size_t written = 0;
        struct private_fecdec_data *pfd = fn->private_data;
        enum fec_group_usability u = group_is_usable(fg, pfd);
 
@@ -276,18 +279,12 @@ static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
        PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
                fg->h.group_num, fg->h.group_bytes,
                fg->h.data_slices_per_group * sb);
-       need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
-       if (need > fn->bufsize) {
-               fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
-               if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
-                       return -E_FECDEC_OVERRUN;
-               PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
-               fn->buf = para_realloc(fn->buf, fn->bufsize);
-       }
        for (; i < fg->h.data_slices_per_group; i++) {
                size_t n = sb;
                if (n + written > fg->h.group_bytes)
                        n = fg->h.group_bytes - written;
+               if (fn->loaded + n > fn->bufsize)
+                       return -E_FECDEC_OVERRUN;
                memcpy(fn->buf + fn->loaded, fg->data[i], n);
                fn->loaded += n;
                written += n;
@@ -394,7 +391,7 @@ static void fecdec_close(struct filter_node *fn)
 
 static void fecdec_open(struct filter_node *fn)
 {
-       fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
+       fn->bufsize = FECDEC_OUTBUF_SIZE;
        fn->buf = para_malloc(fn->bufsize);
        fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
        fn->loaded = 0;