1 /* Copyright (c) 2018, Mellanox Technologies All rights reserved.
3 * This software is available to you under a choice of one of two
4 * licenses. You may choose to be licensed under the terms of the GNU
5 * General Public License (GPL) Version 2, available from the file
6 * COPYING in the main directory of this source tree, or the
7 * OpenIB.org BSD license below:
9 * Redistribution and use in source and binary forms, with or
10 * without modification, are permitted provided that the following
13 * - Redistributions of source code must retain the above
14 * copyright notice, this list of conditions and the following
17 * - Redistributions in binary form must reproduce the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer in the documentation and/or other materials
20 * provided with the distribution.
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
26 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
27 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
28 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 #include <crypto/aead.h>
34 #include <crypto/scatterwalk.h>
35 #include <net/ip6_checksum.h>
39 static void chain_to_walk(struct scatterlist *sg, struct scatter_walk *walk)
41 struct scatterlist *src = walk->sg;
42 int diff = walk->offset - src->offset;
44 sg_set_page(sg, sg_page(src),
45 src->length - diff, walk->offset);
47 scatterwalk_crypto_chain(sg, sg_next(src), 2);
50 static int tls_enc_record(struct aead_request *aead_req,
51 struct crypto_aead *aead, char *aad,
52 char *iv, __be64 rcd_sn,
53 struct scatter_walk *in,
54 struct scatter_walk *out, int *in_len,
55 struct tls_prot_info *prot)
57 unsigned char buf[TLS_HEADER_SIZE + TLS_MAX_IV_SIZE];
58 const struct tls_cipher_desc *cipher_desc;
59 struct scatterlist sg_in[3];
60 struct scatterlist sg_out[3];
61 unsigned int buf_size;
65 cipher_desc = get_cipher_desc(prot->cipher_type);
66 DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
68 buf_size = TLS_HEADER_SIZE + cipher_desc->iv;
69 len = min_t(int, *in_len, buf_size);
71 scatterwalk_copychunks(buf, in, len, 0);
72 scatterwalk_copychunks(buf, out, len, 1);
78 scatterwalk_pagedone(in, 0, 1);
79 scatterwalk_pagedone(out, 1, 1);
81 len = buf[4] | (buf[3] << 8);
82 len -= cipher_desc->iv;
84 tls_make_aad(aad, len - cipher_desc->tag, (char *)&rcd_sn, buf[0], prot);
86 memcpy(iv + cipher_desc->salt, buf + TLS_HEADER_SIZE, cipher_desc->iv);
88 sg_init_table(sg_in, ARRAY_SIZE(sg_in));
89 sg_init_table(sg_out, ARRAY_SIZE(sg_out));
90 sg_set_buf(sg_in, aad, TLS_AAD_SPACE_SIZE);
91 sg_set_buf(sg_out, aad, TLS_AAD_SPACE_SIZE);
92 chain_to_walk(sg_in + 1, in);
93 chain_to_walk(sg_out + 1, out);
97 *in_len += cipher_desc->tag;
98 /* the input buffer doesn't contain the entire record.
99 * trim len accordingly. The resulting authentication tag
100 * will contain garbage, but we don't care, so we won't
101 * include any of it in the output skb
102 * Note that we assume the output buffer length
103 * is larger then input buffer length + tag size
112 scatterwalk_copychunks(NULL, in, len, 2);
113 scatterwalk_pagedone(in, 0, 1);
114 scatterwalk_copychunks(NULL, out, len, 2);
115 scatterwalk_pagedone(out, 1, 1);
118 len -= cipher_desc->tag;
119 aead_request_set_crypt(aead_req, sg_in, sg_out, len, iv);
121 rc = crypto_aead_encrypt(aead_req);
126 static void tls_init_aead_request(struct aead_request *aead_req,
127 struct crypto_aead *aead)
129 aead_request_set_tfm(aead_req, aead);
130 aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
133 static struct aead_request *tls_alloc_aead_request(struct crypto_aead *aead,
136 unsigned int req_size = sizeof(struct aead_request) +
137 crypto_aead_reqsize(aead);
138 struct aead_request *aead_req;
140 aead_req = kzalloc(req_size, flags);
142 tls_init_aead_request(aead_req, aead);
146 static int tls_enc_records(struct aead_request *aead_req,
147 struct crypto_aead *aead, struct scatterlist *sg_in,
148 struct scatterlist *sg_out, char *aad, char *iv,
149 u64 rcd_sn, int len, struct tls_prot_info *prot)
151 struct scatter_walk out, in;
154 scatterwalk_start(&in, sg_in);
155 scatterwalk_start(&out, sg_out);
158 rc = tls_enc_record(aead_req, aead, aad, iv,
159 cpu_to_be64(rcd_sn), &in, &out, &len, prot);
162 } while (rc == 0 && len);
164 scatterwalk_done(&in, 0, 0);
165 scatterwalk_done(&out, 1, 0);
170 /* Can't use icsk->icsk_af_ops->send_check here because the ip addresses
171 * might have been changed by NAT.
173 static void update_chksum(struct sk_buff *skb, int headln)
175 struct tcphdr *th = tcp_hdr(skb);
176 int datalen = skb->len - headln;
177 const struct ipv6hdr *ipv6h;
178 const struct iphdr *iph;
180 /* We only changed the payload so if we are using partial we don't
181 * need to update anything.
183 if (likely(skb->ip_summed == CHECKSUM_PARTIAL))
186 skb->ip_summed = CHECKSUM_PARTIAL;
187 skb->csum_start = skb_transport_header(skb) - skb->head;
188 skb->csum_offset = offsetof(struct tcphdr, check);
190 if (skb->sk->sk_family == AF_INET6) {
191 ipv6h = ipv6_hdr(skb);
192 th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
193 datalen, IPPROTO_TCP, 0);
196 th->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen,
201 static void complete_skb(struct sk_buff *nskb, struct sk_buff *skb, int headln)
203 struct sock *sk = skb->sk;
206 skb_copy_header(nskb, skb);
208 skb_put(nskb, skb->len);
209 memcpy(nskb->data, skb->data, headln);
211 nskb->destructor = skb->destructor;
213 skb->destructor = NULL;
216 update_chksum(nskb, headln);
218 /* sock_efree means skb must gone through skb_orphan_partial() */
219 if (nskb->destructor == sock_efree)
222 delta = nskb->truesize - skb->truesize;
223 if (likely(delta < 0))
224 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc));
226 refcount_add(delta, &sk->sk_wmem_alloc);
229 /* This function may be called after the user socket is already
230 * closed so make sure we don't use anything freed during
231 * tls_sk_proto_close here
234 static int fill_sg_in(struct scatterlist *sg_in,
236 struct tls_offload_context_tx *ctx,
241 int tcp_payload_offset = skb_tcp_all_headers(skb);
242 int payload_len = skb->len - tcp_payload_offset;
243 u32 tcp_seq = ntohl(tcp_hdr(skb)->seq);
244 struct tls_record_info *record;
249 spin_lock_irqsave(&ctx->lock, flags);
250 record = tls_get_record(ctx, tcp_seq, rcd_sn);
252 spin_unlock_irqrestore(&ctx->lock, flags);
256 *sync_size = tcp_seq - tls_record_start_seq(record);
257 if (*sync_size < 0) {
258 int is_start_marker = tls_record_is_start_marker(record);
260 spin_unlock_irqrestore(&ctx->lock, flags);
261 /* This should only occur if the relevant record was
262 * already acked. In that case it should be ok
263 * to drop the packet and avoid retransmission.
265 * There is a corner case where the packet contains
266 * both an acked and a non-acked record.
267 * We currently don't handle that case and rely
268 * on TCP to retransmit a packet that doesn't contain
269 * already acked payload.
271 if (!is_start_marker)
276 remaining = *sync_size;
277 for (i = 0; remaining > 0; i++) {
278 skb_frag_t *frag = &record->frags[i];
280 __skb_frag_ref(frag);
281 sg_set_page(sg_in + i, skb_frag_page(frag),
282 skb_frag_size(frag), skb_frag_off(frag));
284 remaining -= skb_frag_size(frag);
287 sg_in[i].length += remaining;
291 spin_unlock_irqrestore(&ctx->lock, flags);
292 if (skb_to_sgvec(skb, &sg_in[i], tcp_payload_offset, payload_len) < 0)
298 static void fill_sg_out(struct scatterlist sg_out[3], void *buf,
299 struct tls_context *tls_ctx,
300 struct sk_buff *nskb,
301 int tcp_payload_offset,
306 const struct tls_cipher_desc *cipher_desc =
307 get_cipher_desc(tls_ctx->crypto_send.info.cipher_type);
309 sg_set_buf(&sg_out[0], dummy_buf, sync_size);
310 sg_set_buf(&sg_out[1], nskb->data + tcp_payload_offset, payload_len);
311 /* Add room for authentication tag produced by crypto */
312 dummy_buf += sync_size;
313 sg_set_buf(&sg_out[2], dummy_buf, cipher_desc->tag);
316 static struct sk_buff *tls_enc_skb(struct tls_context *tls_ctx,
317 struct scatterlist sg_out[3],
318 struct scatterlist *sg_in,
320 s32 sync_size, u64 rcd_sn)
322 struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
323 int tcp_payload_offset = skb_tcp_all_headers(skb);
324 int payload_len = skb->len - tcp_payload_offset;
325 const struct tls_cipher_desc *cipher_desc;
326 void *buf, *iv, *aad, *dummy_buf, *salt;
327 struct aead_request *aead_req;
328 struct sk_buff *nskb = NULL;
331 aead_req = tls_alloc_aead_request(ctx->aead_send, GFP_ATOMIC);
335 cipher_desc = get_cipher_desc(tls_ctx->crypto_send.info.cipher_type);
336 DEBUG_NET_WARN_ON_ONCE(!cipher_desc || !cipher_desc->offloadable);
338 buf_len = cipher_desc->salt + cipher_desc->iv + TLS_AAD_SPACE_SIZE +
339 sync_size + cipher_desc->tag;
340 buf = kmalloc(buf_len, GFP_ATOMIC);
345 salt = crypto_info_salt(&tls_ctx->crypto_send.info, cipher_desc);
346 memcpy(iv, salt, cipher_desc->salt);
347 aad = buf + cipher_desc->salt + cipher_desc->iv;
348 dummy_buf = aad + TLS_AAD_SPACE_SIZE;
350 nskb = alloc_skb(skb_headroom(skb) + skb->len, GFP_ATOMIC);
354 skb_reserve(nskb, skb_headroom(skb));
356 fill_sg_out(sg_out, buf, tls_ctx, nskb, tcp_payload_offset,
357 payload_len, sync_size, dummy_buf);
359 if (tls_enc_records(aead_req, ctx->aead_send, sg_in, sg_out, aad, iv,
360 rcd_sn, sync_size + payload_len,
361 &tls_ctx->prot_info) < 0)
364 complete_skb(nskb, skb, tcp_payload_offset);
366 /* validate_xmit_skb_list assumes that if the skb wasn't segmented
367 * nskb->prev will point to the skb itself
382 static struct sk_buff *tls_sw_fallback(struct sock *sk, struct sk_buff *skb)
384 int tcp_payload_offset = skb_tcp_all_headers(skb);
385 struct tls_context *tls_ctx = tls_get_ctx(sk);
386 struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
387 int payload_len = skb->len - tcp_payload_offset;
388 struct scatterlist *sg_in, sg_out[3];
389 struct sk_buff *nskb = NULL;
390 int sg_in_max_elements;
396 * MAX_SKB_FRAGS in tls_record_info
397 * MAX_SKB_FRAGS + 1 in SKB head and frags.
399 sg_in_max_elements = 2 * MAX_SKB_FRAGS + 1;
404 sg_in = kmalloc_array(sg_in_max_elements, sizeof(*sg_in), GFP_ATOMIC);
408 sg_init_table(sg_in, sg_in_max_elements);
409 sg_init_table(sg_out, ARRAY_SIZE(sg_out));
411 if (fill_sg_in(sg_in, skb, ctx, &rcd_sn, &sync_size, &resync_sgs)) {
412 /* bypass packets before kernel TLS socket option was set */
413 if (sync_size < 0 && payload_len <= -sync_size)
418 nskb = tls_enc_skb(tls_ctx, sg_out, sg_in, skb, sync_size, rcd_sn);
422 put_page(sg_page(&sg_in[--resync_sgs]));
432 struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
433 struct net_device *dev,
436 if (dev == rcu_dereference_bh(tls_get_ctx(sk)->netdev) ||
437 netif_is_bond_master(dev))
440 return tls_sw_fallback(sk, skb);
442 EXPORT_SYMBOL_GPL(tls_validate_xmit_skb);
444 struct sk_buff *tls_validate_xmit_skb_sw(struct sock *sk,
445 struct net_device *dev,
448 return tls_sw_fallback(sk, skb);
451 struct sk_buff *tls_encrypt_skb(struct sk_buff *skb)
453 return tls_sw_fallback(skb->sk, skb);
455 EXPORT_SYMBOL_GPL(tls_encrypt_skb);
457 int tls_sw_fallback_init(struct sock *sk,
458 struct tls_offload_context_tx *offload_ctx,
459 struct tls_crypto_info *crypto_info)
461 const struct tls_cipher_desc *cipher_desc;
464 cipher_desc = get_cipher_desc(crypto_info->cipher_type);
465 if (!cipher_desc || !cipher_desc->offloadable)
468 offload_ctx->aead_send =
469 crypto_alloc_aead(cipher_desc->cipher_name, 0, CRYPTO_ALG_ASYNC);
470 if (IS_ERR(offload_ctx->aead_send)) {
471 rc = PTR_ERR(offload_ctx->aead_send);
472 pr_err_ratelimited("crypto_alloc_aead failed rc=%d\n", rc);
473 offload_ctx->aead_send = NULL;
477 rc = crypto_aead_setkey(offload_ctx->aead_send,
478 crypto_info_key(crypto_info, cipher_desc),
483 rc = crypto_aead_setauthsize(offload_ctx->aead_send, cipher_desc->tag);
489 crypto_free_aead(offload_ctx->aead_send);