+
+int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
+ struct tcphdr *th)
+{
+ struct scatterlist sg;
+ int err;
+
+ __sum16 old_checksum = th->check;
+ th->check = 0;
+ /* options aren't included in the hash */
+ sg_init_one(&sg, th, sizeof(struct tcphdr));
+ err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
+ th->check = old_checksum;
+ return err;
+}
+
+EXPORT_SYMBOL(tcp_md5_hash_header);
+
+int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
+ struct sk_buff *skb, unsigned header_len)
+{
+ struct scatterlist sg;
+ const struct tcphdr *tp = tcp_hdr(skb);
+ struct hash_desc *desc = &hp->md5_desc;
+ unsigned i;
+ const unsigned head_data_len = skb_headlen(skb) > header_len ?
+ skb_headlen(skb) - header_len : 0;
+ const struct skb_shared_info *shi = skb_shinfo(skb);
+
+ sg_init_table(&sg, 1);
+
+ sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
+ if (crypto_hash_update(desc, &sg, head_data_len))
+ return 1;
+
+ for (i = 0; i < shi->nr_frags; ++i) {
+ const struct skb_frag_struct *f = &shi->frags[i];
+ sg_set_page(&sg, f->page, f->size, f->page_offset);
+ if (crypto_hash_update(desc, &sg, f->size))
+ return 1;
+ }
+
+ return 0;
+}
+
+EXPORT_SYMBOL(tcp_md5_hash_skb_data);
+
+int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
+{
+ struct scatterlist sg;
+
+ sg_init_one(&sg, key->key, key->keylen);
+ return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
+}
+
+EXPORT_SYMBOL(tcp_md5_hash_key);
+