1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2018 Netronome Systems, Inc */
3 /* Copyright (C) 2021 Corigine, Inc */
4 
5 #include <linux/module.h>
6 #include <linux/kernel.h>
7 #include <linux/init.h>
8 #include <linux/netdevice.h>
9 #include <asm/unaligned.h>
10 #include <linux/ktime.h>
11 #include <net/xfrm.h>
12 
13 #include "../nfp_net_ctrl.h"
14 #include "../nfp_net.h"
15 #include "crypto.h"
16 
17 #define NFP_NET_IPSEC_MAX_SA_CNT  (16 * 1024) /* Firmware support a maximum of 16K SA offload */
18 
19 /* IPsec config message cmd codes */
20 enum nfp_ipsec_cfg_mssg_cmd_codes {
21 	NFP_IPSEC_CFG_MSSG_ADD_SA,	 /* Add a new SA */
22 	NFP_IPSEC_CFG_MSSG_INV_SA	 /* Invalidate an existing SA */
23 };
24 
25 /* IPsec config message response codes */
26 enum nfp_ipsec_cfg_mssg_rsp_codes {
27 	NFP_IPSEC_CFG_MSSG_OK,
28 	NFP_IPSEC_CFG_MSSG_FAILED,
29 	NFP_IPSEC_CFG_MSSG_SA_VALID,
30 	NFP_IPSEC_CFG_MSSG_SA_HASH_ADD_FAILED,
31 	NFP_IPSEC_CFG_MSSG_SA_HASH_DEL_FAILED,
32 	NFP_IPSEC_CFG_MSSG_SA_INVALID_CMD
33 };
34 
35 /* Protocol */
36 enum nfp_ipsec_sa_prot {
37 	NFP_IPSEC_PROTOCOL_AH = 0,
38 	NFP_IPSEC_PROTOCOL_ESP = 1
39 };
40 
41 /* Mode */
42 enum nfp_ipsec_sa_mode {
43 	NFP_IPSEC_PROTMODE_TRANSPORT = 0,
44 	NFP_IPSEC_PROTMODE_TUNNEL = 1
45 };
46 
47 /* Cipher types */
48 enum nfp_ipsec_sa_cipher {
49 	NFP_IPSEC_CIPHER_NULL,
50 	NFP_IPSEC_CIPHER_3DES,
51 	NFP_IPSEC_CIPHER_AES128,
52 	NFP_IPSEC_CIPHER_AES192,
53 	NFP_IPSEC_CIPHER_AES256,
54 	NFP_IPSEC_CIPHER_AES128_NULL,
55 	NFP_IPSEC_CIPHER_AES192_NULL,
56 	NFP_IPSEC_CIPHER_AES256_NULL,
57 	NFP_IPSEC_CIPHER_CHACHA20
58 };
59 
60 /* Cipher modes */
61 enum nfp_ipsec_sa_cipher_mode {
62 	NFP_IPSEC_CIMODE_ECB,
63 	NFP_IPSEC_CIMODE_CBC,
64 	NFP_IPSEC_CIMODE_CFB,
65 	NFP_IPSEC_CIMODE_OFB,
66 	NFP_IPSEC_CIMODE_CTR
67 };
68 
69 /* Hash types */
70 enum nfp_ipsec_sa_hash_type {
71 	NFP_IPSEC_HASH_NONE,
72 	NFP_IPSEC_HASH_MD5_96,
73 	NFP_IPSEC_HASH_SHA1_96,
74 	NFP_IPSEC_HASH_SHA256_96,
75 	NFP_IPSEC_HASH_SHA384_96,
76 	NFP_IPSEC_HASH_SHA512_96,
77 	NFP_IPSEC_HASH_MD5_128,
78 	NFP_IPSEC_HASH_SHA1_80,
79 	NFP_IPSEC_HASH_SHA256_128,
80 	NFP_IPSEC_HASH_SHA384_192,
81 	NFP_IPSEC_HASH_SHA512_256,
82 	NFP_IPSEC_HASH_GF128_128,
83 	NFP_IPSEC_HASH_POLY1305_128
84 };
85 
86 /* IPSEC_CFG_MSSG_ADD_SA */
87 struct nfp_ipsec_cfg_add_sa {
88 	u32 ciph_key[8];		  /* Cipher Key */
89 	union {
90 		u32 auth_key[16];	  /* Authentication Key */
91 		struct nfp_ipsec_aesgcm { /* AES-GCM-ESP fields */
92 			u32 salt;	  /* Initialized with SA */
93 			u32 resv[15];
94 		} aesgcm_fields;
95 	};
96 	struct sa_ctrl_word {
97 		uint32_t hash   :4;	  /* From nfp_ipsec_sa_hash_type */
98 		uint32_t cimode :4;	  /* From nfp_ipsec_sa_cipher_mode */
99 		uint32_t cipher :4;	  /* From nfp_ipsec_sa_cipher */
100 		uint32_t mode   :2;	  /* From nfp_ipsec_sa_mode */
101 		uint32_t proto  :2;	  /* From nfp_ipsec_sa_prot */
102 		uint32_t dir :1;	  /* SA direction */
103 		uint32_t resv0 :12;
104 		uint32_t encap_dsbl:1;	  /* Encap/Decap disable */
105 		uint32_t resv1 :2;	  /* Must be set to 0 */
106 	} ctrl_word;
107 	u32 spi;			  /* SPI Value */
108 	uint32_t pmtu_limit :16;          /* PMTU Limit */
109 	uint32_t resv0 :5;
110 	uint32_t ipv6       :1;		  /* Outbound IPv6 addr format */
111 	uint32_t resv1	 :10;
112 	u32 resv2[2];
113 	u32 src_ip[4];			  /* Src IP addr */
114 	u32 dst_ip[4];			  /* Dst IP addr */
115 	u32 resv3[6];
116 };
117 
118 /* IPSEC_CFG_MSSG */
119 struct nfp_ipsec_cfg_mssg {
120 	union {
121 		struct{
122 			uint32_t cmd:16;     /* One of nfp_ipsec_cfg_mssg_cmd_codes */
123 			uint32_t rsp:16;     /* One of nfp_ipsec_cfg_mssg_rsp_codes */
124 			uint32_t sa_idx:16;  /* SA table index */
125 			uint32_t spare0:16;
126 			struct nfp_ipsec_cfg_add_sa cfg_add_sa;
127 		};
128 		u32 raw[64];
129 	};
130 };
131 
132 static int nfp_ipsec_cfg_cmd_issue(struct nfp_net *nn, int type, int saidx,
133 				   struct nfp_ipsec_cfg_mssg *msg)
134 {
135 	unsigned int offset = nn->tlv_caps.mbox_off + NFP_NET_CFG_MBOX_SIMPLE_VAL;
136 	int i, msg_size, ret;
137 
138 	ret = nfp_net_mbox_lock(nn, sizeof(*msg));
139 	if (ret)
140 		return ret;
141 
142 	msg->cmd = type;
143 	msg->sa_idx = saidx;
144 	msg->rsp = 0;
145 	msg_size = ARRAY_SIZE(msg->raw);
146 
147 	for (i = 0; i < msg_size; i++)
148 		nn_writel(nn, offset + 4 * i, msg->raw[i]);
149 
150 	ret = nfp_net_mbox_reconfig(nn, NFP_NET_CFG_MBOX_CMD_IPSEC);
151 	if (ret < 0) {
152 		nn_ctrl_bar_unlock(nn);
153 		return ret;
154 	}
155 
156 	/* For now we always read the whole message response back */
157 	for (i = 0; i < msg_size; i++)
158 		msg->raw[i] = nn_readl(nn, offset + 4 * i);
159 
160 	nn_ctrl_bar_unlock(nn);
161 
162 	switch (msg->rsp) {
163 	case NFP_IPSEC_CFG_MSSG_OK:
164 		return 0;
165 	case NFP_IPSEC_CFG_MSSG_SA_INVALID_CMD:
166 		return -EINVAL;
167 	case NFP_IPSEC_CFG_MSSG_SA_VALID:
168 		return -EEXIST;
169 	case NFP_IPSEC_CFG_MSSG_FAILED:
170 	case NFP_IPSEC_CFG_MSSG_SA_HASH_ADD_FAILED:
171 	case NFP_IPSEC_CFG_MSSG_SA_HASH_DEL_FAILED:
172 		return -EIO;
173 	default:
174 		return -EINVAL;
175 	}
176 }
177 
178 static int set_aes_keylen(struct nfp_ipsec_cfg_add_sa *cfg, int alg, int keylen)
179 {
180 	bool aes_gmac = (alg == SADB_X_EALG_NULL_AES_GMAC);
181 
182 	switch (keylen) {
183 	case 128:
184 		cfg->ctrl_word.cipher = aes_gmac ? NFP_IPSEC_CIPHER_AES128_NULL :
185 						   NFP_IPSEC_CIPHER_AES128;
186 		break;
187 	case 192:
188 		cfg->ctrl_word.cipher = aes_gmac ? NFP_IPSEC_CIPHER_AES192_NULL :
189 						   NFP_IPSEC_CIPHER_AES192;
190 		break;
191 	case 256:
192 		cfg->ctrl_word.cipher = aes_gmac ? NFP_IPSEC_CIPHER_AES256_NULL :
193 						   NFP_IPSEC_CIPHER_AES256;
194 		break;
195 	default:
196 		return -EINVAL;
197 	}
198 
199 	return 0;
200 }
201 
202 static void set_md5hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
203 {
204 	switch (*trunc_len) {
205 	case 96:
206 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_MD5_96;
207 		break;
208 	case 128:
209 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_MD5_128;
210 		break;
211 	default:
212 		*trunc_len = 0;
213 	}
214 }
215 
216 static void set_sha1hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
217 {
218 	switch (*trunc_len) {
219 	case 96:
220 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA1_96;
221 		break;
222 	case 80:
223 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA1_80;
224 		break;
225 	default:
226 		*trunc_len = 0;
227 	}
228 }
229 
230 static void set_sha2_256hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
231 {
232 	switch (*trunc_len) {
233 	case 96:
234 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA256_96;
235 		break;
236 	case 128:
237 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA256_128;
238 		break;
239 	default:
240 		*trunc_len = 0;
241 	}
242 }
243 
244 static void set_sha2_384hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
245 {
246 	switch (*trunc_len) {
247 	case 96:
248 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA384_96;
249 		break;
250 	case 192:
251 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA384_192;
252 		break;
253 	default:
254 		*trunc_len = 0;
255 	}
256 }
257 
258 static void set_sha2_512hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
259 {
260 	switch (*trunc_len) {
261 	case 96:
262 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA512_96;
263 		break;
264 	case 256:
265 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA512_256;
266 		break;
267 	default:
268 		*trunc_len = 0;
269 	}
270 }
271 
272 static int nfp_net_xfrm_add_state(struct xfrm_state *x)
273 {
274 	struct net_device *netdev = x->xso.dev;
275 	struct nfp_ipsec_cfg_mssg msg = {};
276 	int i, key_len, trunc_len, err = 0;
277 	struct nfp_ipsec_cfg_add_sa *cfg;
278 	struct nfp_net *nn;
279 	unsigned int saidx;
280 
281 	nn = netdev_priv(netdev);
282 	cfg = &msg.cfg_add_sa;
283 
284 	/* General */
285 	switch (x->props.mode) {
286 	case XFRM_MODE_TUNNEL:
287 		cfg->ctrl_word.mode = NFP_IPSEC_PROTMODE_TUNNEL;
288 		break;
289 	case XFRM_MODE_TRANSPORT:
290 		cfg->ctrl_word.mode = NFP_IPSEC_PROTMODE_TRANSPORT;
291 		break;
292 	default:
293 		nn_err(nn, "Unsupported mode for xfrm offload\n");
294 		return -EINVAL;
295 	}
296 
297 	switch (x->id.proto) {
298 	case IPPROTO_ESP:
299 		cfg->ctrl_word.proto = NFP_IPSEC_PROTOCOL_ESP;
300 		break;
301 	case IPPROTO_AH:
302 		cfg->ctrl_word.proto = NFP_IPSEC_PROTOCOL_AH;
303 		break;
304 	default:
305 		nn_err(nn, "Unsupported protocol for xfrm offload\n");
306 		return -EINVAL;
307 	}
308 
309 	if (x->props.flags & XFRM_STATE_ESN) {
310 		nn_err(nn, "Unsupported XFRM_REPLAY_MODE_ESN for xfrm offload\n");
311 		return -EINVAL;
312 	}
313 
314 	if (x->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
315 		nn_err(nn, "Unsupported xfrm offload tyoe\n");
316 		return -EINVAL;
317 	}
318 
319 	cfg->spi = ntohl(x->id.spi);
320 
321 	/* Hash/Authentication */
322 	if (x->aalg)
323 		trunc_len = x->aalg->alg_trunc_len;
324 	else
325 		trunc_len = 0;
326 
327 	switch (x->props.aalgo) {
328 	case SADB_AALG_NONE:
329 		if (x->aead) {
330 			trunc_len = -1;
331 		} else {
332 			nn_err(nn, "Unsupported authentication algorithm\n");
333 			return -EINVAL;
334 		}
335 		break;
336 	case SADB_X_AALG_NULL:
337 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_NONE;
338 		trunc_len = -1;
339 		break;
340 	case SADB_AALG_MD5HMAC:
341 		set_md5hmac(cfg, &trunc_len);
342 		break;
343 	case SADB_AALG_SHA1HMAC:
344 		set_sha1hmac(cfg, &trunc_len);
345 		break;
346 	case SADB_X_AALG_SHA2_256HMAC:
347 		set_sha2_256hmac(cfg, &trunc_len);
348 		break;
349 	case SADB_X_AALG_SHA2_384HMAC:
350 		set_sha2_384hmac(cfg, &trunc_len);
351 		break;
352 	case SADB_X_AALG_SHA2_512HMAC:
353 		set_sha2_512hmac(cfg, &trunc_len);
354 		break;
355 	default:
356 		nn_err(nn, "Unsupported authentication algorithm\n");
357 		return -EINVAL;
358 	}
359 
360 	if (!trunc_len) {
361 		nn_err(nn, "Unsupported authentication algorithm trunc length\n");
362 		return -EINVAL;
363 	}
364 
365 	if (x->aalg) {
366 		key_len = DIV_ROUND_UP(x->aalg->alg_key_len, BITS_PER_BYTE);
367 		if (key_len > sizeof(cfg->auth_key)) {
368 			nn_err(nn, "Insufficient space for offloaded auth key\n");
369 			return -EINVAL;
370 		}
371 		for (i = 0; i < key_len / sizeof(cfg->auth_key[0]) ; i++)
372 			cfg->auth_key[i] = get_unaligned_be32(x->aalg->alg_key +
373 							      sizeof(cfg->auth_key[0]) * i);
374 	}
375 
376 	/* Encryption */
377 	switch (x->props.ealgo) {
378 	case SADB_EALG_NONE:
379 	case SADB_EALG_NULL:
380 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CBC;
381 		cfg->ctrl_word.cipher = NFP_IPSEC_CIPHER_NULL;
382 		break;
383 	case SADB_EALG_3DESCBC:
384 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CBC;
385 		cfg->ctrl_word.cipher = NFP_IPSEC_CIPHER_3DES;
386 		break;
387 	case SADB_X_EALG_AES_GCM_ICV16:
388 	case SADB_X_EALG_NULL_AES_GMAC:
389 		if (!x->aead) {
390 			nn_err(nn, "Invalid AES key data\n");
391 			return -EINVAL;
392 		}
393 
394 		if (x->aead->alg_icv_len != 128) {
395 			nn_err(nn, "ICV must be 128bit with SADB_X_EALG_AES_GCM_ICV16\n");
396 			return -EINVAL;
397 		}
398 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CTR;
399 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_GF128_128;
400 
401 		/* Aead->alg_key_len includes 32-bit salt */
402 		if (set_aes_keylen(cfg, x->props.ealgo, x->aead->alg_key_len - 32)) {
403 			nn_err(nn, "Unsupported AES key length %d\n", x->aead->alg_key_len);
404 			return -EINVAL;
405 		}
406 		break;
407 	case SADB_X_EALG_AESCBC:
408 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CBC;
409 		if (!x->ealg) {
410 			nn_err(nn, "Invalid AES key data\n");
411 			return -EINVAL;
412 		}
413 		if (set_aes_keylen(cfg, x->props.ealgo, x->ealg->alg_key_len) < 0) {
414 			nn_err(nn, "Unsupported AES key length %d\n", x->ealg->alg_key_len);
415 			return -EINVAL;
416 		}
417 		break;
418 	default:
419 		nn_err(nn, "Unsupported encryption algorithm for offload\n");
420 		return -EINVAL;
421 	}
422 
423 	if (x->aead) {
424 		int salt_len = 4;
425 
426 		key_len = DIV_ROUND_UP(x->aead->alg_key_len, BITS_PER_BYTE);
427 		key_len -= salt_len;
428 
429 		if (key_len > sizeof(cfg->ciph_key)) {
430 			nn_err(nn, "aead: Insufficient space for offloaded key\n");
431 			return -EINVAL;
432 		}
433 
434 		for (i = 0; i < key_len / sizeof(cfg->ciph_key[0]) ; i++)
435 			cfg->ciph_key[i] = get_unaligned_be32(x->aead->alg_key +
436 							      sizeof(cfg->ciph_key[0]) * i);
437 
438 		/* Load up the salt */
439 		cfg->aesgcm_fields.salt = get_unaligned_be32(x->aead->alg_key + key_len);
440 	}
441 
442 	if (x->ealg) {
443 		key_len = DIV_ROUND_UP(x->ealg->alg_key_len, BITS_PER_BYTE);
444 
445 		if (key_len > sizeof(cfg->ciph_key)) {
446 			nn_err(nn, "ealg: Insufficient space for offloaded key\n");
447 			return -EINVAL;
448 		}
449 		for (i = 0; i < key_len / sizeof(cfg->ciph_key[0]) ; i++)
450 			cfg->ciph_key[i] = get_unaligned_be32(x->ealg->alg_key +
451 							      sizeof(cfg->ciph_key[0]) * i);
452 	}
453 
454 	/* IP related info */
455 	switch (x->props.family) {
456 	case AF_INET:
457 		cfg->ipv6 = 0;
458 		cfg->src_ip[0] = ntohl(x->props.saddr.a4);
459 		cfg->dst_ip[0] = ntohl(x->id.daddr.a4);
460 		break;
461 	case AF_INET6:
462 		cfg->ipv6 = 1;
463 		for (i = 0; i < 4; i++) {
464 			cfg->src_ip[i] = ntohl(x->props.saddr.a6[i]);
465 			cfg->dst_ip[i] = ntohl(x->id.daddr.a6[i]);
466 		}
467 		break;
468 	default:
469 		nn_err(nn, "Unsupported address family\n");
470 		return -EINVAL;
471 	}
472 
473 	/* Maximum nic IPsec code could handle. Other limits may apply. */
474 	cfg->pmtu_limit = 0xffff;
475 	cfg->ctrl_word.encap_dsbl = 1;
476 
477 	/* SA direction */
478 	cfg->ctrl_word.dir = x->xso.dir;
479 
480 	/* Find unused SA data*/
481 	err = xa_alloc(&nn->xa_ipsec, &saidx, x,
482 		       XA_LIMIT(0, NFP_NET_IPSEC_MAX_SA_CNT - 1), GFP_KERNEL);
483 	if (err < 0) {
484 		nn_err(nn, "Unable to get sa_data number for IPsec\n");
485 		return err;
486 	}
487 
488 	/* Allocate saidx and commit the SA */
489 	err = nfp_ipsec_cfg_cmd_issue(nn, NFP_IPSEC_CFG_MSSG_ADD_SA, saidx, &msg);
490 	if (err) {
491 		xa_erase(&nn->xa_ipsec, saidx);
492 		nn_err(nn, "Failed to issue IPsec command err ret=%d\n", err);
493 		return err;
494 	}
495 
496 	/* 0 is invalid offload_handle for kernel */
497 	x->xso.offload_handle = saidx + 1;
498 	return 0;
499 }
500 
501 static void nfp_net_xfrm_del_state(struct xfrm_state *x)
502 {
503 	struct net_device *netdev = x->xso.dev;
504 	struct nfp_ipsec_cfg_mssg msg;
505 	struct nfp_net *nn;
506 	int err;
507 
508 	nn = netdev_priv(netdev);
509 	err = nfp_ipsec_cfg_cmd_issue(nn, NFP_IPSEC_CFG_MSSG_INV_SA,
510 				      x->xso.offload_handle - 1, &msg);
511 	if (err)
512 		nn_warn(nn, "Failed to invalidate SA in hardware\n");
513 
514 	xa_erase(&nn->xa_ipsec, x->xso.offload_handle - 1);
515 }
516 
517 static bool nfp_net_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
518 {
519 	if (x->props.family == AF_INET)
520 		/* Offload with IPv4 options is not supported yet */
521 		return ip_hdr(skb)->ihl == 5;
522 
523 	/* Offload with IPv6 extension headers is not support yet */
524 	return !(ipv6_ext_hdr(ipv6_hdr(skb)->nexthdr));
525 }
526 
527 static const struct xfrmdev_ops nfp_net_ipsec_xfrmdev_ops = {
528 	.xdo_dev_state_add = nfp_net_xfrm_add_state,
529 	.xdo_dev_state_delete = nfp_net_xfrm_del_state,
530 	.xdo_dev_offload_ok = nfp_net_ipsec_offload_ok,
531 };
532 
533 void nfp_net_ipsec_init(struct nfp_net *nn)
534 {
535 	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_IPSEC))
536 		return;
537 
538 	xa_init_flags(&nn->xa_ipsec, XA_FLAGS_ALLOC);
539 	nn->dp.netdev->xfrmdev_ops = &nfp_net_ipsec_xfrmdev_ops;
540 }
541 
542 void nfp_net_ipsec_clean(struct nfp_net *nn)
543 {
544 	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_IPSEC))
545 		return;
546 
547 	WARN_ON(!xa_empty(&nn->xa_ipsec));
548 	xa_destroy(&nn->xa_ipsec);
549 }
550 
551 bool nfp_net_ipsec_tx_prep(struct nfp_net_dp *dp, struct sk_buff *skb,
552 			   struct nfp_ipsec_offload *offload_info)
553 {
554 	struct xfrm_offload *xo = xfrm_offload(skb);
555 	struct xfrm_state *x;
556 
557 	x = xfrm_input_state(skb);
558 	if (!x)
559 		return false;
560 
561 	offload_info->seq_hi = xo->seq.hi;
562 	offload_info->seq_low = xo->seq.low;
563 	offload_info->handle = x->xso.offload_handle;
564 
565 	return true;
566 }
567 
568 int nfp_net_ipsec_rx(struct nfp_meta_parsed *meta, struct sk_buff *skb)
569 {
570 	struct net_device *netdev = skb->dev;
571 	struct xfrm_offload *xo;
572 	struct xfrm_state *x;
573 	struct sec_path *sp;
574 	struct nfp_net *nn;
575 	u32 saidx;
576 
577 	nn = netdev_priv(netdev);
578 
579 	saidx = meta->ipsec_saidx - 1;
580 	if (saidx >= NFP_NET_IPSEC_MAX_SA_CNT)
581 		return -EINVAL;
582 
583 	sp = secpath_set(skb);
584 	if (unlikely(!sp))
585 		return -ENOMEM;
586 
587 	xa_lock(&nn->xa_ipsec);
588 	x = xa_load(&nn->xa_ipsec, saidx);
589 	xa_unlock(&nn->xa_ipsec);
590 	if (!x)
591 		return -EINVAL;
592 
593 	xfrm_state_hold(x);
594 	sp->xvec[sp->len++] = x;
595 	sp->olen++;
596 	xo = xfrm_offload(skb);
597 	xo->flags = CRYPTO_DONE;
598 	xo->status = CRYPTO_SUCCESS;
599 
600 	return 0;
601 }
602