xref: /linux/drivers/net/ethernet/netronome/nfp/crypto/tls.c (revision 31d166642c7c601c65eccf0ff2e0afe9a0538be2)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2019 Netronome Systems, Inc. */
3 
4 #include <linux/bitfield.h>
5 #include <linux/ipv6.h>
6 #include <linux/skbuff.h>
7 #include <net/tls.h>
8 
9 #include "../ccm.h"
10 #include "../nfp_net.h"
11 #include "crypto.h"
12 #include "fw.h"
13 
14 #define NFP_NET_TLS_CCM_MBOX_OPS_MASK		\
15 	(BIT(NFP_CCM_TYPE_CRYPTO_RESET) |	\
16 	 BIT(NFP_CCM_TYPE_CRYPTO_ADD) |		\
17 	 BIT(NFP_CCM_TYPE_CRYPTO_DEL) |		\
18 	 BIT(NFP_CCM_TYPE_CRYPTO_UPDATE))
19 
20 #define NFP_NET_TLS_OPCODE_MASK_RX			\
21 	BIT(NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_DEC)
22 
23 #define NFP_NET_TLS_OPCODE_MASK_TX			\
24 	BIT(NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_ENC)
25 
26 #define NFP_NET_TLS_OPCODE_MASK						\
27 	(NFP_NET_TLS_OPCODE_MASK_RX | NFP_NET_TLS_OPCODE_MASK_TX)
28 
29 static void nfp_net_crypto_set_op(struct nfp_net *nn, u8 opcode, bool on)
30 {
31 	u32 off, val;
32 
33 	off = nn->tlv_caps.crypto_enable_off + round_down(opcode / 8, 4);
34 
35 	val = nn_readl(nn, off);
36 	if (on)
37 		val |= BIT(opcode & 31);
38 	else
39 		val &= ~BIT(opcode & 31);
40 	nn_writel(nn, off, val);
41 }
42 
43 static bool
44 __nfp_net_tls_conn_cnt_changed(struct nfp_net *nn, int add,
45 			       enum tls_offload_ctx_dir direction)
46 {
47 	u8 opcode;
48 	int cnt;
49 
50 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
51 		opcode = NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_ENC;
52 		nn->ktls_tx_conn_cnt += add;
53 		cnt = nn->ktls_tx_conn_cnt;
54 		nn->dp.ktls_tx = !!nn->ktls_tx_conn_cnt;
55 	} else {
56 		opcode = NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_DEC;
57 		nn->ktls_rx_conn_cnt += add;
58 		cnt = nn->ktls_rx_conn_cnt;
59 	}
60 
61 	/* Care only about 0 -> 1 and 1 -> 0 transitions */
62 	if (cnt > 1)
63 		return false;
64 
65 	nfp_net_crypto_set_op(nn, opcode, cnt);
66 	return true;
67 }
68 
69 static int
70 nfp_net_tls_conn_cnt_changed(struct nfp_net *nn, int add,
71 			     enum tls_offload_ctx_dir direction)
72 {
73 	int ret = 0;
74 
75 	/* Use the BAR lock to protect the connection counts */
76 	nn_ctrl_bar_lock(nn);
77 	if (__nfp_net_tls_conn_cnt_changed(nn, add, direction)) {
78 		ret = __nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_CRYPTO);
79 		/* Undo the cnt adjustment if failed */
80 		if (ret)
81 			__nfp_net_tls_conn_cnt_changed(nn, -add, direction);
82 	}
83 	nn_ctrl_bar_unlock(nn);
84 
85 	return ret;
86 }
87 
88 static int
89 nfp_net_tls_conn_add(struct nfp_net *nn, enum tls_offload_ctx_dir direction)
90 {
91 	return nfp_net_tls_conn_cnt_changed(nn, 1, direction);
92 }
93 
94 static int
95 nfp_net_tls_conn_remove(struct nfp_net *nn, enum tls_offload_ctx_dir direction)
96 {
97 	return nfp_net_tls_conn_cnt_changed(nn, -1, direction);
98 }
99 
100 static struct sk_buff *
101 nfp_net_tls_alloc_simple(struct nfp_net *nn, size_t req_sz, gfp_t flags)
102 {
103 	return nfp_ccm_mbox_msg_alloc(nn, req_sz,
104 				      sizeof(struct nfp_crypto_reply_simple),
105 				      flags);
106 }
107 
108 static int
109 nfp_net_tls_communicate_simple(struct nfp_net *nn, struct sk_buff *skb,
110 			       const char *name, enum nfp_ccm_type type)
111 {
112 	struct nfp_crypto_reply_simple *reply;
113 	int err;
114 
115 	err = nfp_ccm_mbox_communicate(nn, skb, type,
116 				       sizeof(*reply), sizeof(*reply));
117 	if (err) {
118 		nn_dp_warn(&nn->dp, "failed to %s TLS: %d\n", name, err);
119 		return err;
120 	}
121 
122 	reply = (void *)skb->data;
123 	err = -be32_to_cpu(reply->error);
124 	if (err)
125 		nn_dp_warn(&nn->dp, "failed to %s TLS, fw replied: %d\n",
126 			   name, err);
127 	dev_consume_skb_any(skb);
128 
129 	return err;
130 }
131 
132 static void nfp_net_tls_del_fw(struct nfp_net *nn, __be32 *fw_handle)
133 {
134 	struct nfp_crypto_req_del *req;
135 	struct sk_buff *skb;
136 
137 	skb = nfp_net_tls_alloc_simple(nn, sizeof(*req), GFP_KERNEL);
138 	if (!skb)
139 		return;
140 
141 	req = (void *)skb->data;
142 	req->ep_id = 0;
143 	memcpy(req->handle, fw_handle, sizeof(req->handle));
144 
145 	nfp_net_tls_communicate_simple(nn, skb, "delete",
146 				       NFP_CCM_TYPE_CRYPTO_DEL);
147 }
148 
149 static struct nfp_crypto_req_add_back *
150 nfp_net_tls_set_ipv4(struct nfp_crypto_req_add_v4 *req, struct sock *sk,
151 		     int direction)
152 {
153 	struct inet_sock *inet = inet_sk(sk);
154 
155 	req->front.key_len += sizeof(__be32) * 2;
156 	req->front.ipver_vlan = cpu_to_be16(FIELD_PREP(NFP_NET_TLS_IPVER, 4) |
157 					    FIELD_PREP(NFP_NET_TLS_VLAN,
158 						       NFP_NET_TLS_VLAN_UNUSED));
159 
160 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
161 		req->src_ip = inet->inet_saddr;
162 		req->dst_ip = inet->inet_daddr;
163 	} else {
164 		req->src_ip = inet->inet_daddr;
165 		req->dst_ip = inet->inet_saddr;
166 	}
167 
168 	return &req->back;
169 }
170 
171 static struct nfp_crypto_req_add_back *
172 nfp_net_tls_set_ipv6(struct nfp_crypto_req_add_v6 *req, struct sock *sk,
173 		     int direction)
174 {
175 #if IS_ENABLED(CONFIG_IPV6)
176 	struct ipv6_pinfo *np = inet6_sk(sk);
177 
178 	req->front.key_len += sizeof(struct in6_addr) * 2;
179 	req->front.ipver_vlan = cpu_to_be16(FIELD_PREP(NFP_NET_TLS_IPVER, 6) |
180 					    FIELD_PREP(NFP_NET_TLS_VLAN,
181 						       NFP_NET_TLS_VLAN_UNUSED));
182 
183 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
184 		memcpy(req->src_ip, &np->saddr, sizeof(req->src_ip));
185 		memcpy(req->dst_ip, &sk->sk_v6_daddr, sizeof(req->dst_ip));
186 	} else {
187 		memcpy(req->src_ip, &sk->sk_v6_daddr, sizeof(req->src_ip));
188 		memcpy(req->dst_ip, &np->saddr, sizeof(req->dst_ip));
189 	}
190 
191 #endif
192 	return &req->back;
193 }
194 
195 static void
196 nfp_net_tls_set_l4(struct nfp_crypto_req_add_front *front,
197 		   struct nfp_crypto_req_add_back *back, struct sock *sk,
198 		   int direction)
199 {
200 	struct inet_sock *inet = inet_sk(sk);
201 
202 	front->l4_proto = IPPROTO_TCP;
203 
204 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
205 		back->src_port = inet->inet_sport;
206 		back->dst_port = inet->inet_dport;
207 	} else {
208 		back->src_port = inet->inet_dport;
209 		back->dst_port = inet->inet_sport;
210 	}
211 }
212 
213 static u8 nfp_tls_1_2_dir_to_opcode(enum tls_offload_ctx_dir direction)
214 {
215 	switch (direction) {
216 	case TLS_OFFLOAD_CTX_DIR_TX:
217 		return NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_ENC;
218 	case TLS_OFFLOAD_CTX_DIR_RX:
219 		return NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_DEC;
220 	default:
221 		WARN_ON_ONCE(1);
222 		return 0;
223 	}
224 }
225 
226 static bool
227 nfp_net_cipher_supported(struct nfp_net *nn, u16 cipher_type,
228 			 enum tls_offload_ctx_dir direction)
229 {
230 	u8 bit;
231 
232 	switch (cipher_type) {
233 	case TLS_CIPHER_AES_GCM_128:
234 		if (direction == TLS_OFFLOAD_CTX_DIR_TX)
235 			bit = NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_ENC;
236 		else
237 			bit = NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_DEC;
238 		break;
239 	default:
240 		return false;
241 	}
242 
243 	return nn->tlv_caps.crypto_ops & BIT(bit);
244 }
245 
246 static int
247 nfp_net_tls_add(struct net_device *netdev, struct sock *sk,
248 		enum tls_offload_ctx_dir direction,
249 		struct tls_crypto_info *crypto_info,
250 		u32 start_offload_tcp_sn)
251 {
252 	struct tls12_crypto_info_aes_gcm_128 *tls_ci;
253 	struct nfp_net *nn = netdev_priv(netdev);
254 	struct nfp_crypto_req_add_front *front;
255 	struct nfp_net_tls_offload_ctx *ntls;
256 	struct nfp_crypto_req_add_back *back;
257 	struct nfp_crypto_reply_add *reply;
258 	struct sk_buff *skb;
259 	size_t req_sz;
260 	bool ipv6;
261 	int err;
262 
263 	BUILD_BUG_ON(sizeof(struct nfp_net_tls_offload_ctx) >
264 		     TLS_DRIVER_STATE_SIZE_TX);
265 	BUILD_BUG_ON(offsetof(struct nfp_net_tls_offload_ctx, rx_end) >
266 		     TLS_DRIVER_STATE_SIZE_RX);
267 
268 	if (!nfp_net_cipher_supported(nn, crypto_info->cipher_type, direction))
269 		return -EOPNOTSUPP;
270 
271 	switch (sk->sk_family) {
272 #if IS_ENABLED(CONFIG_IPV6)
273 	case AF_INET6:
274 		if (sk->sk_ipv6only ||
275 		    ipv6_addr_type(&sk->sk_v6_daddr) != IPV6_ADDR_MAPPED) {
276 			req_sz = sizeof(struct nfp_crypto_req_add_v6);
277 			ipv6 = true;
278 			break;
279 		}
280 #endif
281 		/* fall through */
282 	case AF_INET:
283 		req_sz = sizeof(struct nfp_crypto_req_add_v4);
284 		ipv6 = false;
285 		break;
286 	default:
287 		return -EOPNOTSUPP;
288 	}
289 
290 	err = nfp_net_tls_conn_add(nn, direction);
291 	if (err)
292 		return err;
293 
294 	skb = nfp_ccm_mbox_msg_alloc(nn, req_sz, sizeof(*reply), GFP_KERNEL);
295 	if (!skb) {
296 		err = -ENOMEM;
297 		goto err_conn_remove;
298 	}
299 
300 	front = (void *)skb->data;
301 	front->ep_id = 0;
302 	front->key_len = 8;
303 	front->opcode = nfp_tls_1_2_dir_to_opcode(direction);
304 	memset(front->resv, 0, sizeof(front->resv));
305 
306 	if (ipv6)
307 		back = nfp_net_tls_set_ipv6((void *)skb->data, sk, direction);
308 	else
309 		back = nfp_net_tls_set_ipv4((void *)skb->data, sk, direction);
310 
311 	nfp_net_tls_set_l4(front, back, sk, direction);
312 
313 	back->counter = 0;
314 	back->tcp_seq = cpu_to_be32(start_offload_tcp_sn);
315 
316 	tls_ci = (struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
317 	memcpy(back->key, tls_ci->key, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
318 	memset(&back->key[TLS_CIPHER_AES_GCM_128_KEY_SIZE / 4], 0,
319 	       sizeof(back->key) - TLS_CIPHER_AES_GCM_128_KEY_SIZE);
320 	memcpy(back->iv, tls_ci->iv, TLS_CIPHER_AES_GCM_128_IV_SIZE);
321 	memcpy(&back->salt, tls_ci->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
322 	memcpy(back->rec_no, tls_ci->rec_seq, sizeof(tls_ci->rec_seq));
323 
324 	err = nfp_ccm_mbox_communicate(nn, skb, NFP_CCM_TYPE_CRYPTO_ADD,
325 				       sizeof(*reply), sizeof(*reply));
326 	if (err) {
327 		nn_dp_warn(&nn->dp, "failed to add TLS: %d\n", err);
328 		/* communicate frees skb on error */
329 		goto err_conn_remove;
330 	}
331 
332 	reply = (void *)skb->data;
333 	err = -be32_to_cpu(reply->error);
334 	if (err) {
335 		if (err == -ENOSPC) {
336 			if (!atomic_fetch_inc(&nn->ktls_no_space))
337 				nn_info(nn, "HW TLS table full\n");
338 		} else {
339 			nn_dp_warn(&nn->dp,
340 				   "failed to add TLS, FW replied: %d\n", err);
341 		}
342 		goto err_free_skb;
343 	}
344 
345 	if (!reply->handle[0] && !reply->handle[1]) {
346 		nn_dp_warn(&nn->dp, "FW returned NULL handle\n");
347 		err = -EINVAL;
348 		goto err_fw_remove;
349 	}
350 
351 	ntls = tls_driver_ctx(sk, direction);
352 	memcpy(ntls->fw_handle, reply->handle, sizeof(ntls->fw_handle));
353 	if (direction == TLS_OFFLOAD_CTX_DIR_TX)
354 		ntls->next_seq = start_offload_tcp_sn;
355 	dev_consume_skb_any(skb);
356 
357 	if (direction == TLS_OFFLOAD_CTX_DIR_TX)
358 		return 0;
359 
360 	tls_offload_rx_resync_set_type(sk,
361 				       TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT);
362 	return 0;
363 
364 err_fw_remove:
365 	nfp_net_tls_del_fw(nn, reply->handle);
366 err_free_skb:
367 	dev_consume_skb_any(skb);
368 err_conn_remove:
369 	nfp_net_tls_conn_remove(nn, direction);
370 	return err;
371 }
372 
373 static void
374 nfp_net_tls_del(struct net_device *netdev, struct tls_context *tls_ctx,
375 		enum tls_offload_ctx_dir direction)
376 {
377 	struct nfp_net *nn = netdev_priv(netdev);
378 	struct nfp_net_tls_offload_ctx *ntls;
379 
380 	nfp_net_tls_conn_remove(nn, direction);
381 
382 	ntls = __tls_driver_ctx(tls_ctx, direction);
383 	nfp_net_tls_del_fw(nn, ntls->fw_handle);
384 }
385 
386 static void
387 nfp_net_tls_resync(struct net_device *netdev, struct sock *sk, u32 seq,
388 		   u8 *rcd_sn, enum tls_offload_ctx_dir direction)
389 {
390 	struct nfp_net *nn = netdev_priv(netdev);
391 	struct nfp_net_tls_offload_ctx *ntls;
392 	struct nfp_crypto_req_update *req;
393 	struct sk_buff *skb;
394 	gfp_t flags;
395 
396 	flags = direction == TLS_OFFLOAD_CTX_DIR_TX ? GFP_KERNEL : GFP_ATOMIC;
397 	skb = nfp_net_tls_alloc_simple(nn, sizeof(*req), flags);
398 	if (!skb)
399 		return;
400 
401 	ntls = tls_driver_ctx(sk, direction);
402 	req = (void *)skb->data;
403 	req->ep_id = 0;
404 	req->opcode = nfp_tls_1_2_dir_to_opcode(direction);
405 	memset(req->resv, 0, sizeof(req->resv));
406 	memcpy(req->handle, ntls->fw_handle, sizeof(ntls->fw_handle));
407 	req->tcp_seq = cpu_to_be32(seq);
408 	memcpy(req->rec_no, rcd_sn, sizeof(req->rec_no));
409 
410 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
411 		nfp_net_tls_communicate_simple(nn, skb, "sync",
412 					       NFP_CCM_TYPE_CRYPTO_UPDATE);
413 		ntls->next_seq = seq;
414 	} else {
415 		nfp_ccm_mbox_post(nn, skb, NFP_CCM_TYPE_CRYPTO_UPDATE,
416 				  sizeof(struct nfp_crypto_reply_simple));
417 	}
418 }
419 
420 static const struct tlsdev_ops nfp_net_tls_ops = {
421 	.tls_dev_add = nfp_net_tls_add,
422 	.tls_dev_del = nfp_net_tls_del,
423 	.tls_dev_resync = nfp_net_tls_resync,
424 };
425 
426 static int nfp_net_tls_reset(struct nfp_net *nn)
427 {
428 	struct nfp_crypto_req_reset *req;
429 	struct sk_buff *skb;
430 
431 	skb = nfp_net_tls_alloc_simple(nn, sizeof(*req), GFP_KERNEL);
432 	if (!skb)
433 		return -ENOMEM;
434 
435 	req = (void *)skb->data;
436 	req->ep_id = 0;
437 
438 	return nfp_net_tls_communicate_simple(nn, skb, "reset",
439 					      NFP_CCM_TYPE_CRYPTO_RESET);
440 }
441 
442 int nfp_net_tls_init(struct nfp_net *nn)
443 {
444 	struct net_device *netdev = nn->dp.netdev;
445 	int err;
446 
447 	if (!(nn->tlv_caps.crypto_ops & NFP_NET_TLS_OPCODE_MASK))
448 		return 0;
449 
450 	if ((nn->tlv_caps.mbox_cmsg_types & NFP_NET_TLS_CCM_MBOX_OPS_MASK) !=
451 	    NFP_NET_TLS_CCM_MBOX_OPS_MASK)
452 		return 0;
453 
454 	if (!nfp_ccm_mbox_fits(nn, sizeof(struct nfp_crypto_req_add_v6))) {
455 		nn_warn(nn, "disabling TLS offload - mbox too small: %d\n",
456 			nn->tlv_caps.mbox_len);
457 		return 0;
458 	}
459 
460 	err = nfp_net_tls_reset(nn);
461 	if (err)
462 		return err;
463 
464 	nn_ctrl_bar_lock(nn);
465 	nn_writel(nn, nn->tlv_caps.crypto_enable_off, 0);
466 	err = __nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_CRYPTO);
467 	nn_ctrl_bar_unlock(nn);
468 	if (err)
469 		return err;
470 
471 	if (nn->tlv_caps.crypto_ops & NFP_NET_TLS_OPCODE_MASK_RX) {
472 		netdev->hw_features |= NETIF_F_HW_TLS_RX;
473 		netdev->features |= NETIF_F_HW_TLS_RX;
474 	}
475 	if (nn->tlv_caps.crypto_ops & NFP_NET_TLS_OPCODE_MASK_TX) {
476 		netdev->hw_features |= NETIF_F_HW_TLS_TX;
477 		netdev->features |= NETIF_F_HW_TLS_TX;
478 	}
479 
480 	netdev->tlsdev_ops = &nfp_net_tls_ops;
481 
482 	return 0;
483 }
484