1 /*
2  * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
33 
34 #include "en_accel/tls.h"
35 #include "en_accel/tls_rxtx.h"
36 #include "accel/accel.h"
37 
38 #include <net/inet6_hashtables.h>
39 #include <linux/ipv6.h>
40 
41 #define SYNDROM_DECRYPTED  0x30
42 #define SYNDROM_RESYNC_REQUEST 0x31
43 #define SYNDROM_AUTH_FAILED 0x32
44 
45 #define SYNDROME_OFFLOAD_REQUIRED 32
46 #define SYNDROME_SYNC 33
47 
48 struct sync_info {
49 	u64 rcd_sn;
50 	s32 sync_len;
51 	int nr_frags;
52 	skb_frag_t frags[MAX_SKB_FRAGS];
53 };
54 
55 struct recv_metadata_content {
56 	u8 syndrome;
57 	u8 reserved;
58 	__be32 sync_seq;
59 } __packed;
60 
61 struct send_metadata_content {
62 	/* One byte of syndrome followed by 3 bytes of swid */
63 	__be32 syndrome_swid;
64 	__be16 first_seq;
65 } __packed;
66 
67 struct mlx5e_tls_metadata {
68 	union {
69 		/* from fpga to host */
70 		struct recv_metadata_content recv;
71 		/* from host to fpga */
72 		struct send_metadata_content send;
73 		unsigned char raw[6];
74 	} __packed content;
75 	/* packet type ID field	*/
76 	__be16 ethertype;
77 } __packed;
78 
mlx5e_tls_add_metadata(struct sk_buff * skb,__be32 swid)79 static int mlx5e_tls_add_metadata(struct sk_buff *skb, __be32 swid)
80 {
81 	struct mlx5e_tls_metadata *pet;
82 	struct ethhdr *eth;
83 
84 	if (skb_cow_head(skb, sizeof(struct mlx5e_tls_metadata)))
85 		return -ENOMEM;
86 
87 	eth = (struct ethhdr *)skb_push(skb, sizeof(struct mlx5e_tls_metadata));
88 	skb->mac_header -= sizeof(struct mlx5e_tls_metadata);
89 	pet = (struct mlx5e_tls_metadata *)(eth + 1);
90 
91 	memmove(skb->data, skb->data + sizeof(struct mlx5e_tls_metadata),
92 		2 * ETH_ALEN);
93 
94 	eth->h_proto = cpu_to_be16(MLX5E_METADATA_ETHER_TYPE);
95 	pet->content.send.syndrome_swid =
96 		htonl(SYNDROME_OFFLOAD_REQUIRED << 24) | swid;
97 
98 	return 0;
99 }
100 
mlx5e_tls_get_sync_data(struct mlx5e_tls_offload_context_tx * context,u32 tcp_seq,struct sync_info * info)101 static int mlx5e_tls_get_sync_data(struct mlx5e_tls_offload_context_tx *context,
102 				   u32 tcp_seq, struct sync_info *info)
103 {
104 	int remaining, i = 0, ret = -EINVAL;
105 	struct tls_record_info *record;
106 	unsigned long flags;
107 	s32 sync_size;
108 
109 	spin_lock_irqsave(&context->base.lock, flags);
110 	record = tls_get_record(&context->base, tcp_seq, &info->rcd_sn);
111 
112 	if (unlikely(!record))
113 		goto out;
114 
115 	sync_size = tcp_seq - tls_record_start_seq(record);
116 	info->sync_len = sync_size;
117 	if (unlikely(sync_size < 0)) {
118 		if (tls_record_is_start_marker(record))
119 			goto done;
120 
121 		goto out;
122 	}
123 
124 	remaining = sync_size;
125 	while (remaining > 0) {
126 		info->frags[i] = record->frags[i];
127 		__skb_frag_ref(&info->frags[i]);
128 		remaining -= skb_frag_size(&info->frags[i]);
129 
130 		if (remaining < 0)
131 			skb_frag_size_add(&info->frags[i], remaining);
132 
133 		i++;
134 	}
135 	info->nr_frags = i;
136 done:
137 	ret = 0;
138 out:
139 	spin_unlock_irqrestore(&context->base.lock, flags);
140 	return ret;
141 }
142 
mlx5e_tls_complete_sync_skb(struct sk_buff * skb,struct sk_buff * nskb,u32 tcp_seq,int headln,__be64 rcd_sn)143 static void mlx5e_tls_complete_sync_skb(struct sk_buff *skb,
144 					struct sk_buff *nskb, u32 tcp_seq,
145 					int headln, __be64 rcd_sn)
146 {
147 	struct mlx5e_tls_metadata *pet;
148 	u8 syndrome = SYNDROME_SYNC;
149 	struct iphdr *iph;
150 	struct tcphdr *th;
151 	int data_len, mss;
152 
153 	nskb->dev = skb->dev;
154 	skb_reset_mac_header(nskb);
155 	skb_set_network_header(nskb, skb_network_offset(skb));
156 	skb_set_transport_header(nskb, skb_transport_offset(skb));
157 	memcpy(nskb->data, skb->data, headln);
158 	memcpy(nskb->data + headln, &rcd_sn, sizeof(rcd_sn));
159 
160 	iph = ip_hdr(nskb);
161 	iph->tot_len = htons(nskb->len - skb_network_offset(nskb));
162 	th = tcp_hdr(nskb);
163 	data_len = nskb->len - headln;
164 	tcp_seq -= data_len;
165 	th->seq = htonl(tcp_seq);
166 
167 	mss = nskb->dev->mtu - (headln - skb_network_offset(nskb));
168 	skb_shinfo(nskb)->gso_size = 0;
169 	if (data_len > mss) {
170 		skb_shinfo(nskb)->gso_size = mss;
171 		skb_shinfo(nskb)->gso_segs = DIV_ROUND_UP(data_len, mss);
172 	}
173 	skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type;
174 
175 	pet = (struct mlx5e_tls_metadata *)(nskb->data + sizeof(struct ethhdr));
176 	memcpy(pet, &syndrome, sizeof(syndrome));
177 	pet->content.send.first_seq = htons(tcp_seq);
178 
179 	/* MLX5 devices don't care about the checksum partial start, offset
180 	 * and pseudo header
181 	 */
182 	nskb->ip_summed = CHECKSUM_PARTIAL;
183 
184 	nskb->queue_mapping = skb->queue_mapping;
185 }
186 
mlx5e_tls_handle_ooo(struct mlx5e_tls_offload_context_tx * context,struct mlx5e_txqsq * sq,struct sk_buff * skb,struct mlx5e_tls * tls)187 static bool mlx5e_tls_handle_ooo(struct mlx5e_tls_offload_context_tx *context,
188 				 struct mlx5e_txqsq *sq, struct sk_buff *skb,
189 				 struct mlx5e_tls *tls)
190 {
191 	u32 tcp_seq = ntohl(tcp_hdr(skb)->seq);
192 	struct sync_info info;
193 	struct sk_buff *nskb;
194 	int linear_len = 0;
195 	int headln;
196 	int i;
197 
198 	sq->stats->tls_ooo++;
199 
200 	if (mlx5e_tls_get_sync_data(context, tcp_seq, &info)) {
201 		/* We might get here if a retransmission reaches the driver
202 		 * after the relevant record is acked.
203 		 * It should be safe to drop the packet in this case
204 		 */
205 		atomic64_inc(&tls->sw_stats.tx_tls_drop_no_sync_data);
206 		goto err_out;
207 	}
208 
209 	if (unlikely(info.sync_len < 0)) {
210 		u32 payload;
211 
212 		headln = skb_transport_offset(skb) + tcp_hdrlen(skb);
213 		payload = skb->len - headln;
214 		if (likely(payload <= -info.sync_len))
215 			/* SKB payload doesn't require offload
216 			 */
217 			return true;
218 
219 		atomic64_inc(&tls->sw_stats.tx_tls_drop_bypass_required);
220 		goto err_out;
221 	}
222 
223 	if (unlikely(mlx5e_tls_add_metadata(skb, context->swid))) {
224 		atomic64_inc(&tls->sw_stats.tx_tls_drop_metadata);
225 		goto err_out;
226 	}
227 
228 	headln = skb_transport_offset(skb) + tcp_hdrlen(skb);
229 	linear_len += headln + sizeof(info.rcd_sn);
230 	nskb = alloc_skb(linear_len, GFP_ATOMIC);
231 	if (unlikely(!nskb)) {
232 		atomic64_inc(&tls->sw_stats.tx_tls_drop_resync_alloc);
233 		goto err_out;
234 	}
235 
236 	context->expected_seq = tcp_seq + skb->len - headln;
237 	skb_put(nskb, linear_len);
238 	for (i = 0; i < info.nr_frags; i++)
239 		skb_shinfo(nskb)->frags[i] = info.frags[i];
240 
241 	skb_shinfo(nskb)->nr_frags = info.nr_frags;
242 	nskb->data_len = info.sync_len;
243 	nskb->len += info.sync_len;
244 	sq->stats->tls_resync_bytes += nskb->len;
245 	mlx5e_tls_complete_sync_skb(skb, nskb, tcp_seq, headln,
246 				    cpu_to_be64(info.rcd_sn));
247 	mlx5e_sq_xmit_simple(sq, nskb, true);
248 
249 	return true;
250 
251 err_out:
252 	dev_kfree_skb_any(skb);
253 	return false;
254 }
255 
mlx5e_tls_handle_tx_skb(struct net_device * netdev,struct mlx5e_txqsq * sq,struct sk_buff * skb,struct mlx5e_accel_tx_tls_state * state)256 bool mlx5e_tls_handle_tx_skb(struct net_device *netdev, struct mlx5e_txqsq *sq,
257 			     struct sk_buff *skb, struct mlx5e_accel_tx_tls_state *state)
258 {
259 	struct mlx5e_priv *priv = netdev_priv(netdev);
260 	struct mlx5e_tls_offload_context_tx *context;
261 	struct tls_context *tls_ctx;
262 	u32 expected_seq;
263 	int datalen;
264 	u32 skb_seq;
265 
266 	if (!skb->sk || !tls_is_sk_tx_device_offloaded(skb->sk))
267 		return true;
268 
269 	datalen = skb->len - (skb_transport_offset(skb) + tcp_hdrlen(skb));
270 	if (!datalen)
271 		return true;
272 
273 	mlx5e_tx_mpwqe_ensure_complete(sq);
274 
275 	tls_ctx = tls_get_ctx(skb->sk);
276 	if (WARN_ON_ONCE(tls_ctx->netdev != netdev))
277 		goto err_out;
278 
279 	if (mlx5_accel_is_ktls_tx(sq->channel->mdev))
280 		return mlx5e_ktls_handle_tx_skb(tls_ctx, sq, skb, datalen, state);
281 
282 	/* FPGA */
283 	skb_seq = ntohl(tcp_hdr(skb)->seq);
284 	context = mlx5e_get_tls_tx_context(tls_ctx);
285 	expected_seq = context->expected_seq;
286 
287 	if (unlikely(expected_seq != skb_seq))
288 		return mlx5e_tls_handle_ooo(context, sq, skb, priv->tls);
289 
290 	if (unlikely(mlx5e_tls_add_metadata(skb, context->swid))) {
291 		atomic64_inc(&priv->tls->sw_stats.tx_tls_drop_metadata);
292 		dev_kfree_skb_any(skb);
293 		return false;
294 	}
295 
296 	context->expected_seq = skb_seq + datalen;
297 	return true;
298 
299 err_out:
300 	dev_kfree_skb_any(skb);
301 	return false;
302 }
303 
mlx5e_tls_handle_tx_wqe(struct mlx5e_txqsq * sq,struct mlx5_wqe_ctrl_seg * cseg,struct mlx5e_accel_tx_tls_state * state)304 void mlx5e_tls_handle_tx_wqe(struct mlx5e_txqsq *sq, struct mlx5_wqe_ctrl_seg *cseg,
305 			     struct mlx5e_accel_tx_tls_state *state)
306 {
307 	cseg->tis_tir_num = cpu_to_be32(state->tls_tisn << 8);
308 }
309 
tls_update_resync_sn(struct net_device * netdev,struct sk_buff * skb,struct mlx5e_tls_metadata * mdata)310 static int tls_update_resync_sn(struct net_device *netdev,
311 				struct sk_buff *skb,
312 				struct mlx5e_tls_metadata *mdata)
313 {
314 	struct sock *sk = NULL;
315 	struct iphdr *iph;
316 	struct tcphdr *th;
317 	__be32 seq;
318 
319 	if (mdata->ethertype != htons(ETH_P_IP))
320 		return -EINVAL;
321 
322 	iph = (struct iphdr *)(mdata + 1);
323 
324 	th = ((void *)iph) + iph->ihl * 4;
325 
326 	if (iph->version == 4) {
327 		sk = inet_lookup_established(dev_net(netdev), &tcp_hashinfo,
328 					     iph->saddr, th->source, iph->daddr,
329 					     th->dest, netdev->ifindex);
330 #if IS_ENABLED(CONFIG_IPV6)
331 	} else {
332 		struct ipv6hdr *ipv6h = (struct ipv6hdr *)iph;
333 
334 		sk = __inet6_lookup_established(dev_net(netdev), &tcp_hashinfo,
335 						&ipv6h->saddr, th->source,
336 						&ipv6h->daddr, ntohs(th->dest),
337 						netdev->ifindex, 0);
338 #endif
339 	}
340 	if (!sk || sk->sk_state == TCP_TIME_WAIT) {
341 		struct mlx5e_priv *priv = netdev_priv(netdev);
342 
343 		atomic64_inc(&priv->tls->sw_stats.rx_tls_drop_resync_request);
344 		goto out;
345 	}
346 
347 	skb->sk = sk;
348 	skb->destructor = sock_edemux;
349 
350 	memcpy(&seq, &mdata->content.recv.sync_seq, sizeof(seq));
351 	tls_offload_rx_resync_request(sk, seq);
352 out:
353 	return 0;
354 }
355 
356 /* FPGA tls rx handler */
mlx5e_tls_handle_rx_skb_metadata(struct mlx5e_rq * rq,struct sk_buff * skb,u32 * cqe_bcnt)357 void mlx5e_tls_handle_rx_skb_metadata(struct mlx5e_rq *rq, struct sk_buff *skb,
358 				      u32 *cqe_bcnt)
359 {
360 	struct mlx5e_tls_metadata *mdata;
361 	struct mlx5e_priv *priv;
362 
363 	/* Use the metadata */
364 	mdata = (struct mlx5e_tls_metadata *)(skb->data + ETH_HLEN);
365 	switch (mdata->content.recv.syndrome) {
366 	case SYNDROM_DECRYPTED:
367 		skb->decrypted = 1;
368 		break;
369 	case SYNDROM_RESYNC_REQUEST:
370 		tls_update_resync_sn(rq->netdev, skb, mdata);
371 		priv = netdev_priv(rq->netdev);
372 		atomic64_inc(&priv->tls->sw_stats.rx_tls_resync_request);
373 		break;
374 	case SYNDROM_AUTH_FAILED:
375 		/* Authentication failure will be observed and verified by kTLS */
376 		priv = netdev_priv(rq->netdev);
377 		atomic64_inc(&priv->tls->sw_stats.rx_tls_auth_fail);
378 		break;
379 	default:
380 		/* Bypass the metadata header to others */
381 		return;
382 	}
383 
384 	remove_metadata_hdr(skb);
385 	*cqe_bcnt -= MLX5E_METADATA_ETHER_LEN;
386 }
387 
mlx5e_tls_get_stop_room(struct mlx5e_txqsq * sq)388 u16 mlx5e_tls_get_stop_room(struct mlx5e_txqsq *sq)
389 {
390 	struct mlx5_core_dev *mdev = sq->channel->mdev;
391 
392 	if (!mlx5_accel_is_tls_device(mdev))
393 		return 0;
394 
395 	if (mlx5_accel_is_ktls_device(mdev))
396 		return mlx5e_ktls_get_stop_room(sq);
397 
398 	/* FPGA */
399 	/* Resync SKB. */
400 	return mlx5e_stop_room_for_wqe(MLX5_SEND_WQE_MAX_WQEBBS);
401 }
402