diff options
| -rw-r--r-- | net/tls/tls_sw.c | 80 |
1 files changed, 79 insertions, 1 deletions
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 52fbe727d7c1..4ba62cd00a94 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -43,6 +43,82 @@ #define MAX_IV_SIZE TLS_CIPHER_AES_GCM_128_IV_SIZE +static int __skb_nsg(struct sk_buff *skb, int offset, int len, + unsigned int recursion_level) +{ + int start = skb_headlen(skb); + int i, chunk = start - offset; + struct sk_buff *frag_iter; + int elt = 0; + + if (unlikely(recursion_level >= 24)) + return -EMSGSIZE; + + if (chunk > 0) { + if (chunk > len) + chunk = len; + elt++; + len -= chunk; + if (len == 0) + return elt; + offset += chunk; + } + + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + int end; + + WARN_ON(start > offset + len); + + end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]); + chunk = end - offset; + if (chunk > 0) { + if (chunk > len) + chunk = len; + elt++; + len -= chunk; + if (len == 0) + return elt; + offset += chunk; + } + start = end; + } + + if (unlikely(skb_has_frag_list(skb))) { + skb_walk_frags(skb, frag_iter) { + int end, ret; + + WARN_ON(start > offset + len); + + end = start + frag_iter->len; + chunk = end - offset; + if (chunk > 0) { + if (chunk > len) + chunk = len; + ret = __skb_nsg(frag_iter, offset - start, chunk, + recursion_level + 1); + if (unlikely(ret < 0)) + return ret; + elt += ret; + len -= chunk; + if (len == 0) + return elt; + offset += chunk; + } + start = end; + } + } + BUG_ON(len); + return elt; +} + +/* Return the number of scatterlist elements required to completely map the + * skb, or -EMSGSIZE if the recursion depth is exceeded. + */ +static int skb_nsg(struct sk_buff *skb, int offset, int len) +{ + return __skb_nsg(skb, offset, len, 0); +} + static int tls_do_decryption(struct sock *sk, struct scatterlist *sgin, struct scatterlist *sgout, @@ -678,12 +754,14 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, n_sgout = iov_iter_npages(out_iov, INT_MAX) + 1; else n_sgout = sg_nents(out_sg); + n_sgin = skb_nsg(skb, rxm->offset + tls_ctx->rx.prepend_size, + rxm->full_len - tls_ctx->rx.prepend_size); } else { n_sgout = 0; *zc = false; + n_sgin = skb_cow_data(skb, 0, &unused); } - n_sgin = skb_cow_data(skb, 0, &unused); if (n_sgin < 1) return -EBADMSG; |