xref: /linux/drivers/net/ethernet/netronome/nfp/crypto/tls.c (revision ff8869d5ed4e798c6dad89809689cb9d2e2ab2f8)
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 					 type == NFP_CCM_TYPE_CRYPTO_DEL);
118 	if (err) {
119 		nn_dp_warn(&nn->dp, "failed to %s TLS: %d\n", name, err);
120 		return err;
121 	}
122 
123 	reply = (void *)skb->data;
124 	err = -be32_to_cpu(reply->error);
125 	if (err)
126 		nn_dp_warn(&nn->dp, "failed to %s TLS, fw replied: %d\n",
127 			   name, err);
128 	dev_consume_skb_any(skb);
129 
130 	return err;
131 }
132 
133 static void nfp_net_tls_del_fw(struct nfp_net *nn, __be32 *fw_handle)
134 {
135 	struct nfp_crypto_req_del *req;
136 	struct sk_buff *skb;
137 
138 	skb = nfp_net_tls_alloc_simple(nn, sizeof(*req), GFP_KERNEL);
139 	if (!skb)
140 		return;
141 
142 	req = (void *)skb->data;
143 	req->ep_id = 0;
144 	memcpy(req->handle, fw_handle, sizeof(req->handle));
145 
146 	nfp_net_tls_communicate_simple(nn, skb, "delete",
147 				       NFP_CCM_TYPE_CRYPTO_DEL);
148 }
149 
150 static void
151 nfp_net_tls_set_ipver_vlan(struct nfp_crypto_req_add_front *front, u8 ipver)
152 {
153 	front->ipver_vlan = cpu_to_be16(FIELD_PREP(NFP_NET_TLS_IPVER, ipver) |
154 					FIELD_PREP(NFP_NET_TLS_VLAN,
155 						   NFP_NET_TLS_VLAN_UNUSED));
156 }
157 
158 static struct nfp_crypto_req_add_back *
159 nfp_net_tls_set_ipv4(struct nfp_crypto_req_add_v4 *req, struct sock *sk,
160 		     int direction)
161 {
162 	struct inet_sock *inet = inet_sk(sk);
163 
164 	req->front.key_len += sizeof(__be32) * 2;
165 
166 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
167 		req->src_ip = inet->inet_saddr;
168 		req->dst_ip = inet->inet_daddr;
169 	} else {
170 		req->src_ip = inet->inet_daddr;
171 		req->dst_ip = inet->inet_saddr;
172 	}
173 
174 	return &req->back;
175 }
176 
177 static struct nfp_crypto_req_add_back *
178 nfp_net_tls_set_ipv6(struct nfp_crypto_req_add_v6 *req, struct sock *sk,
179 		     int direction)
180 {
181 #if IS_ENABLED(CONFIG_IPV6)
182 	struct ipv6_pinfo *np = inet6_sk(sk);
183 
184 	req->front.key_len += sizeof(struct in6_addr) * 2;
185 
186 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
187 		memcpy(req->src_ip, &np->saddr, sizeof(req->src_ip));
188 		memcpy(req->dst_ip, &sk->sk_v6_daddr, sizeof(req->dst_ip));
189 	} else {
190 		memcpy(req->src_ip, &sk->sk_v6_daddr, sizeof(req->src_ip));
191 		memcpy(req->dst_ip, &np->saddr, sizeof(req->dst_ip));
192 	}
193 
194 #endif
195 	return &req->back;
196 }
197 
198 static void
199 nfp_net_tls_set_l4(struct nfp_crypto_req_add_front *front,
200 		   struct nfp_crypto_req_add_back *back, struct sock *sk,
201 		   int direction)
202 {
203 	struct inet_sock *inet = inet_sk(sk);
204 
205 	front->l4_proto = IPPROTO_TCP;
206 
207 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
208 		back->src_port = inet->inet_sport;
209 		back->dst_port = inet->inet_dport;
210 	} else {
211 		back->src_port = inet->inet_dport;
212 		back->dst_port = inet->inet_sport;
213 	}
214 }
215 
216 static u8 nfp_tls_1_2_dir_to_opcode(enum tls_offload_ctx_dir direction)
217 {
218 	switch (direction) {
219 	case TLS_OFFLOAD_CTX_DIR_TX:
220 		return NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_ENC;
221 	case TLS_OFFLOAD_CTX_DIR_RX:
222 		return NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_DEC;
223 	default:
224 		WARN_ON_ONCE(1);
225 		return 0;
226 	}
227 }
228 
229 static bool
230 nfp_net_cipher_supported(struct nfp_net *nn, u16 cipher_type,
231 			 enum tls_offload_ctx_dir direction)
232 {
233 	u8 bit;
234 
235 	switch (cipher_type) {
236 	case TLS_CIPHER_AES_GCM_128:
237 		if (direction == TLS_OFFLOAD_CTX_DIR_TX)
238 			bit = NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_ENC;
239 		else
240 			bit = NFP_NET_CRYPTO_OP_TLS_1_2_AES_GCM_128_DEC;
241 		break;
242 	default:
243 		return false;
244 	}
245 
246 	return nn->tlv_caps.crypto_ops & BIT(bit);
247 }
248 
249 static int
250 nfp_net_tls_add(struct net_device *netdev, struct sock *sk,
251 		enum tls_offload_ctx_dir direction,
252 		struct tls_crypto_info *crypto_info,
253 		u32 start_offload_tcp_sn)
254 {
255 	struct tls12_crypto_info_aes_gcm_128 *tls_ci;
256 	struct nfp_net *nn = netdev_priv(netdev);
257 	struct nfp_crypto_req_add_front *front;
258 	struct nfp_net_tls_offload_ctx *ntls;
259 	struct nfp_crypto_req_add_back *back;
260 	struct nfp_crypto_reply_add *reply;
261 	struct sk_buff *skb;
262 	size_t req_sz;
263 	bool ipv6;
264 	int err;
265 
266 	BUILD_BUG_ON(sizeof(struct nfp_net_tls_offload_ctx) >
267 		     TLS_DRIVER_STATE_SIZE_TX);
268 	BUILD_BUG_ON(offsetof(struct nfp_net_tls_offload_ctx, rx_end) >
269 		     TLS_DRIVER_STATE_SIZE_RX);
270 
271 	if (!nfp_net_cipher_supported(nn, crypto_info->cipher_type, direction))
272 		return -EOPNOTSUPP;
273 
274 	switch (sk->sk_family) {
275 #if IS_ENABLED(CONFIG_IPV6)
276 	case AF_INET6:
277 		if (sk->sk_ipv6only ||
278 		    ipv6_addr_type(&sk->sk_v6_daddr) != IPV6_ADDR_MAPPED) {
279 			req_sz = sizeof(struct nfp_crypto_req_add_v6);
280 			ipv6 = true;
281 			break;
282 		}
283 #endif
284 		/* fall through */
285 	case AF_INET:
286 		req_sz = sizeof(struct nfp_crypto_req_add_v4);
287 		ipv6 = false;
288 		break;
289 	default:
290 		return -EOPNOTSUPP;
291 	}
292 
293 	err = nfp_net_tls_conn_add(nn, direction);
294 	if (err)
295 		return err;
296 
297 	skb = nfp_ccm_mbox_msg_alloc(nn, req_sz, sizeof(*reply), GFP_KERNEL);
298 	if (!skb) {
299 		err = -ENOMEM;
300 		goto err_conn_remove;
301 	}
302 
303 	front = (void *)skb->data;
304 	front->ep_id = 0;
305 	front->key_len = 8;
306 	front->opcode = nfp_tls_1_2_dir_to_opcode(direction);
307 	memset(front->resv, 0, sizeof(front->resv));
308 
309 	nfp_net_tls_set_ipver_vlan(front, ipv6 ? 6 : 4);
310 
311 	if (ipv6)
312 		back = nfp_net_tls_set_ipv6((void *)skb->data, sk, direction);
313 	else
314 		back = nfp_net_tls_set_ipv4((void *)skb->data, sk, direction);
315 
316 	nfp_net_tls_set_l4(front, back, sk, direction);
317 
318 	back->counter = 0;
319 	back->tcp_seq = cpu_to_be32(start_offload_tcp_sn);
320 
321 	tls_ci = (struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
322 	memcpy(back->key, tls_ci->key, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
323 	memset(&back->key[TLS_CIPHER_AES_GCM_128_KEY_SIZE / 4], 0,
324 	       sizeof(back->key) - TLS_CIPHER_AES_GCM_128_KEY_SIZE);
325 	memcpy(back->iv, tls_ci->iv, TLS_CIPHER_AES_GCM_128_IV_SIZE);
326 	memcpy(&back->salt, tls_ci->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
327 	memcpy(back->rec_no, tls_ci->rec_seq, sizeof(tls_ci->rec_seq));
328 
329 	err = nfp_ccm_mbox_communicate(nn, skb, NFP_CCM_TYPE_CRYPTO_ADD,
330 				       sizeof(*reply), sizeof(*reply));
331 	if (err) {
332 		nn_dp_warn(&nn->dp, "failed to add TLS: %d\n", err);
333 		/* communicate frees skb on error */
334 		goto err_conn_remove;
335 	}
336 
337 	reply = (void *)skb->data;
338 	err = -be32_to_cpu(reply->error);
339 	if (err) {
340 		if (err == -ENOSPC) {
341 			if (!atomic_fetch_inc(&nn->ktls_no_space))
342 				nn_info(nn, "HW TLS table full\n");
343 		} else {
344 			nn_dp_warn(&nn->dp,
345 				   "failed to add TLS, FW replied: %d\n", err);
346 		}
347 		goto err_free_skb;
348 	}
349 
350 	if (!reply->handle[0] && !reply->handle[1]) {
351 		nn_dp_warn(&nn->dp, "FW returned NULL handle\n");
352 		err = -EINVAL;
353 		goto err_fw_remove;
354 	}
355 
356 	ntls = tls_driver_ctx(sk, direction);
357 	memcpy(ntls->fw_handle, reply->handle, sizeof(ntls->fw_handle));
358 	if (direction == TLS_OFFLOAD_CTX_DIR_TX)
359 		ntls->next_seq = start_offload_tcp_sn;
360 	dev_consume_skb_any(skb);
361 
362 	if (direction == TLS_OFFLOAD_CTX_DIR_TX)
363 		return 0;
364 
365 	tls_offload_rx_resync_set_type(sk,
366 				       TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT);
367 	return 0;
368 
369 err_fw_remove:
370 	nfp_net_tls_del_fw(nn, reply->handle);
371 err_free_skb:
372 	dev_consume_skb_any(skb);
373 err_conn_remove:
374 	nfp_net_tls_conn_remove(nn, direction);
375 	return err;
376 }
377 
378 static void
379 nfp_net_tls_del(struct net_device *netdev, struct tls_context *tls_ctx,
380 		enum tls_offload_ctx_dir direction)
381 {
382 	struct nfp_net *nn = netdev_priv(netdev);
383 	struct nfp_net_tls_offload_ctx *ntls;
384 
385 	nfp_net_tls_conn_remove(nn, direction);
386 
387 	ntls = __tls_driver_ctx(tls_ctx, direction);
388 	nfp_net_tls_del_fw(nn, ntls->fw_handle);
389 }
390 
391 static void
392 nfp_net_tls_resync(struct net_device *netdev, struct sock *sk, u32 seq,
393 		   u8 *rcd_sn, enum tls_offload_ctx_dir direction)
394 {
395 	struct nfp_net *nn = netdev_priv(netdev);
396 	struct nfp_net_tls_offload_ctx *ntls;
397 	struct nfp_crypto_req_update *req;
398 	struct sk_buff *skb;
399 	gfp_t flags;
400 
401 	flags = direction == TLS_OFFLOAD_CTX_DIR_TX ? GFP_KERNEL : GFP_ATOMIC;
402 	skb = nfp_net_tls_alloc_simple(nn, sizeof(*req), flags);
403 	if (!skb)
404 		return;
405 
406 	ntls = tls_driver_ctx(sk, direction);
407 	req = (void *)skb->data;
408 	req->ep_id = 0;
409 	req->opcode = nfp_tls_1_2_dir_to_opcode(direction);
410 	memset(req->resv, 0, sizeof(req->resv));
411 	memcpy(req->handle, ntls->fw_handle, sizeof(ntls->fw_handle));
412 	req->tcp_seq = cpu_to_be32(seq);
413 	memcpy(req->rec_no, rcd_sn, sizeof(req->rec_no));
414 
415 	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
416 		nfp_net_tls_communicate_simple(nn, skb, "sync",
417 					       NFP_CCM_TYPE_CRYPTO_UPDATE);
418 		ntls->next_seq = seq;
419 	} else {
420 		nfp_ccm_mbox_post(nn, skb, NFP_CCM_TYPE_CRYPTO_UPDATE,
421 				  sizeof(struct nfp_crypto_reply_simple));
422 	}
423 }
424 
425 static const struct tlsdev_ops nfp_net_tls_ops = {
426 	.tls_dev_add = nfp_net_tls_add,
427 	.tls_dev_del = nfp_net_tls_del,
428 	.tls_dev_resync = nfp_net_tls_resync,
429 };
430 
431 static int nfp_net_tls_reset(struct nfp_net *nn)
432 {
433 	struct nfp_crypto_req_reset *req;
434 	struct sk_buff *skb;
435 
436 	skb = nfp_net_tls_alloc_simple(nn, sizeof(*req), GFP_KERNEL);
437 	if (!skb)
438 		return -ENOMEM;
439 
440 	req = (void *)skb->data;
441 	req->ep_id = 0;
442 
443 	return nfp_net_tls_communicate_simple(nn, skb, "reset",
444 					      NFP_CCM_TYPE_CRYPTO_RESET);
445 }
446 
447 int nfp_net_tls_init(struct nfp_net *nn)
448 {
449 	struct net_device *netdev = nn->dp.netdev;
450 	int err;
451 
452 	if (!(nn->tlv_caps.crypto_ops & NFP_NET_TLS_OPCODE_MASK))
453 		return 0;
454 
455 	if ((nn->tlv_caps.mbox_cmsg_types & NFP_NET_TLS_CCM_MBOX_OPS_MASK) !=
456 	    NFP_NET_TLS_CCM_MBOX_OPS_MASK)
457 		return 0;
458 
459 	if (!nfp_ccm_mbox_fits(nn, sizeof(struct nfp_crypto_req_add_v6))) {
460 		nn_warn(nn, "disabling TLS offload - mbox too small: %d\n",
461 			nn->tlv_caps.mbox_len);
462 		return 0;
463 	}
464 
465 	err = nfp_net_tls_reset(nn);
466 	if (err)
467 		return err;
468 
469 	nn_ctrl_bar_lock(nn);
470 	nn_writel(nn, nn->tlv_caps.crypto_enable_off, 0);
471 	err = __nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_CRYPTO);
472 	nn_ctrl_bar_unlock(nn);
473 	if (err)
474 		return err;
475 
476 	if (nn->tlv_caps.crypto_ops & NFP_NET_TLS_OPCODE_MASK_RX) {
477 		netdev->hw_features |= NETIF_F_HW_TLS_RX;
478 		netdev->features |= NETIF_F_HW_TLS_RX;
479 	}
480 	if (nn->tlv_caps.crypto_ops & NFP_NET_TLS_OPCODE_MASK_TX) {
481 		netdev->hw_features |= NETIF_F_HW_TLS_TX;
482 		netdev->features |= NETIF_F_HW_TLS_TX;
483 	}
484 
485 	netdev->tlsdev_ops = &nfp_net_tls_ops;
486 
487 	return 0;
488 }
489