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 	int i, msg_size, ret;
136 
137 	msg->cmd = type;
138 	msg->sa_idx = saidx;
139 	msg->rsp = 0;
140 	msg_size = ARRAY_SIZE(msg->raw);
141 
142 	for (i = 0; i < msg_size; i++)
143 		nn_writel(nn, NFP_NET_CFG_MBOX_VAL + 4 * i, msg->raw[i]);
144 
145 	ret = nfp_net_mbox_reconfig(nn, NFP_NET_CFG_MBOX_CMD_IPSEC);
146 	if (ret < 0)
147 		return ret;
148 
149 	/* For now we always read the whole message response back */
150 	for (i = 0; i < msg_size; i++)
151 		msg->raw[i] = nn_readl(nn, NFP_NET_CFG_MBOX_VAL + 4 * i);
152 
153 	switch (msg->rsp) {
154 	case NFP_IPSEC_CFG_MSSG_OK:
155 		return 0;
156 	case NFP_IPSEC_CFG_MSSG_SA_INVALID_CMD:
157 		return -EINVAL;
158 	case NFP_IPSEC_CFG_MSSG_SA_VALID:
159 		return -EEXIST;
160 	case NFP_IPSEC_CFG_MSSG_FAILED:
161 	case NFP_IPSEC_CFG_MSSG_SA_HASH_ADD_FAILED:
162 	case NFP_IPSEC_CFG_MSSG_SA_HASH_DEL_FAILED:
163 		return -EIO;
164 	default:
165 		return -EINVAL;
166 	}
167 }
168 
169 static int set_aes_keylen(struct nfp_ipsec_cfg_add_sa *cfg, int alg, int keylen)
170 {
171 	bool aes_gmac = (alg == SADB_X_EALG_NULL_AES_GMAC);
172 
173 	switch (keylen) {
174 	case 128:
175 		cfg->ctrl_word.cipher = aes_gmac ? NFP_IPSEC_CIPHER_AES128_NULL :
176 						   NFP_IPSEC_CIPHER_AES128;
177 		break;
178 	case 192:
179 		cfg->ctrl_word.cipher = aes_gmac ? NFP_IPSEC_CIPHER_AES192_NULL :
180 						   NFP_IPSEC_CIPHER_AES192;
181 		break;
182 	case 256:
183 		cfg->ctrl_word.cipher = aes_gmac ? NFP_IPSEC_CIPHER_AES256_NULL :
184 						   NFP_IPSEC_CIPHER_AES256;
185 		break;
186 	default:
187 		return -EINVAL;
188 	}
189 
190 	return 0;
191 }
192 
193 static void set_md5hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
194 {
195 	switch (*trunc_len) {
196 	case 96:
197 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_MD5_96;
198 		break;
199 	case 128:
200 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_MD5_128;
201 		break;
202 	default:
203 		*trunc_len = 0;
204 	}
205 }
206 
207 static void set_sha1hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
208 {
209 	switch (*trunc_len) {
210 	case 96:
211 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA1_96;
212 		break;
213 	case 80:
214 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA1_80;
215 		break;
216 	default:
217 		*trunc_len = 0;
218 	}
219 }
220 
221 static void set_sha2_256hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
222 {
223 	switch (*trunc_len) {
224 	case 96:
225 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA256_96;
226 		break;
227 	case 128:
228 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA256_128;
229 		break;
230 	default:
231 		*trunc_len = 0;
232 	}
233 }
234 
235 static void set_sha2_384hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
236 {
237 	switch (*trunc_len) {
238 	case 96:
239 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA384_96;
240 		break;
241 	case 192:
242 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA384_192;
243 		break;
244 	default:
245 		*trunc_len = 0;
246 	}
247 }
248 
249 static void set_sha2_512hmac(struct nfp_ipsec_cfg_add_sa *cfg, int *trunc_len)
250 {
251 	switch (*trunc_len) {
252 	case 96:
253 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA512_96;
254 		break;
255 	case 256:
256 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_SHA512_256;
257 		break;
258 	default:
259 		*trunc_len = 0;
260 	}
261 }
262 
263 static int nfp_net_xfrm_add_state(struct xfrm_state *x)
264 {
265 	struct net_device *netdev = x->xso.dev;
266 	struct nfp_ipsec_cfg_mssg msg = {};
267 	int i, key_len, trunc_len, err = 0;
268 	struct nfp_ipsec_cfg_add_sa *cfg;
269 	struct nfp_net *nn;
270 	unsigned int saidx;
271 
272 	nn = netdev_priv(netdev);
273 	cfg = &msg.cfg_add_sa;
274 
275 	/* General */
276 	switch (x->props.mode) {
277 	case XFRM_MODE_TUNNEL:
278 		cfg->ctrl_word.mode = NFP_IPSEC_PROTMODE_TUNNEL;
279 		break;
280 	case XFRM_MODE_TRANSPORT:
281 		cfg->ctrl_word.mode = NFP_IPSEC_PROTMODE_TRANSPORT;
282 		break;
283 	default:
284 		nn_err(nn, "Unsupported mode for xfrm offload\n");
285 		return -EINVAL;
286 	}
287 
288 	switch (x->id.proto) {
289 	case IPPROTO_ESP:
290 		cfg->ctrl_word.proto = NFP_IPSEC_PROTOCOL_ESP;
291 		break;
292 	case IPPROTO_AH:
293 		cfg->ctrl_word.proto = NFP_IPSEC_PROTOCOL_AH;
294 		break;
295 	default:
296 		nn_err(nn, "Unsupported protocol for xfrm offload\n");
297 		return -EINVAL;
298 	}
299 
300 	if (x->props.flags & XFRM_STATE_ESN) {
301 		nn_err(nn, "Unsupported XFRM_REPLAY_MODE_ESN for xfrm offload\n");
302 		return -EINVAL;
303 	}
304 
305 	if (x->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
306 		nn_err(nn, "Unsupported xfrm offload tyoe\n");
307 		return -EINVAL;
308 	}
309 
310 	cfg->spi = ntohl(x->id.spi);
311 
312 	/* Hash/Authentication */
313 	if (x->aalg)
314 		trunc_len = x->aalg->alg_trunc_len;
315 	else
316 		trunc_len = 0;
317 
318 	switch (x->props.aalgo) {
319 	case SADB_AALG_NONE:
320 		if (x->aead) {
321 			trunc_len = -1;
322 		} else {
323 			nn_err(nn, "Unsupported authentication algorithm\n");
324 			return -EINVAL;
325 		}
326 		break;
327 	case SADB_X_AALG_NULL:
328 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_NONE;
329 		trunc_len = -1;
330 		break;
331 	case SADB_AALG_MD5HMAC:
332 		set_md5hmac(cfg, &trunc_len);
333 		break;
334 	case SADB_AALG_SHA1HMAC:
335 		set_sha1hmac(cfg, &trunc_len);
336 		break;
337 	case SADB_X_AALG_SHA2_256HMAC:
338 		set_sha2_256hmac(cfg, &trunc_len);
339 		break;
340 	case SADB_X_AALG_SHA2_384HMAC:
341 		set_sha2_384hmac(cfg, &trunc_len);
342 		break;
343 	case SADB_X_AALG_SHA2_512HMAC:
344 		set_sha2_512hmac(cfg, &trunc_len);
345 		break;
346 	default:
347 		nn_err(nn, "Unsupported authentication algorithm\n");
348 		return -EINVAL;
349 	}
350 
351 	if (!trunc_len) {
352 		nn_err(nn, "Unsupported authentication algorithm trunc length\n");
353 		return -EINVAL;
354 	}
355 
356 	if (x->aalg) {
357 		key_len = DIV_ROUND_UP(x->aalg->alg_key_len, BITS_PER_BYTE);
358 		if (key_len > sizeof(cfg->auth_key)) {
359 			nn_err(nn, "Insufficient space for offloaded auth key\n");
360 			return -EINVAL;
361 		}
362 		for (i = 0; i < key_len / sizeof(cfg->auth_key[0]) ; i++)
363 			cfg->auth_key[i] = get_unaligned_be32(x->aalg->alg_key +
364 							      sizeof(cfg->auth_key[0]) * i);
365 	}
366 
367 	/* Encryption */
368 	switch (x->props.ealgo) {
369 	case SADB_EALG_NONE:
370 	case SADB_EALG_NULL:
371 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CBC;
372 		cfg->ctrl_word.cipher = NFP_IPSEC_CIPHER_NULL;
373 		break;
374 	case SADB_EALG_3DESCBC:
375 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CBC;
376 		cfg->ctrl_word.cipher = NFP_IPSEC_CIPHER_3DES;
377 		break;
378 	case SADB_X_EALG_AES_GCM_ICV16:
379 	case SADB_X_EALG_NULL_AES_GMAC:
380 		if (!x->aead) {
381 			nn_err(nn, "Invalid AES key data\n");
382 			return -EINVAL;
383 		}
384 
385 		if (x->aead->alg_icv_len != 128) {
386 			nn_err(nn, "ICV must be 128bit with SADB_X_EALG_AES_GCM_ICV16\n");
387 			return -EINVAL;
388 		}
389 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CTR;
390 		cfg->ctrl_word.hash = NFP_IPSEC_HASH_GF128_128;
391 
392 		/* Aead->alg_key_len includes 32-bit salt */
393 		if (set_aes_keylen(cfg, x->props.ealgo, x->aead->alg_key_len - 32)) {
394 			nn_err(nn, "Unsupported AES key length %d\n", x->aead->alg_key_len);
395 			return -EINVAL;
396 		}
397 		break;
398 	case SADB_X_EALG_AESCBC:
399 		cfg->ctrl_word.cimode = NFP_IPSEC_CIMODE_CBC;
400 		if (!x->ealg) {
401 			nn_err(nn, "Invalid AES key data\n");
402 			return -EINVAL;
403 		}
404 		if (set_aes_keylen(cfg, x->props.ealgo, x->ealg->alg_key_len) < 0) {
405 			nn_err(nn, "Unsupported AES key length %d\n", x->ealg->alg_key_len);
406 			return -EINVAL;
407 		}
408 		break;
409 	default:
410 		nn_err(nn, "Unsupported encryption algorithm for offload\n");
411 		return -EINVAL;
412 	}
413 
414 	if (x->aead) {
415 		int salt_len = 4;
416 
417 		key_len = DIV_ROUND_UP(x->aead->alg_key_len, BITS_PER_BYTE);
418 		key_len -= salt_len;
419 
420 		if (key_len > sizeof(cfg->ciph_key)) {
421 			nn_err(nn, "aead: Insufficient space for offloaded key\n");
422 			return -EINVAL;
423 		}
424 
425 		for (i = 0; i < key_len / sizeof(cfg->ciph_key[0]) ; i++)
426 			cfg->ciph_key[i] = get_unaligned_be32(x->aead->alg_key +
427 							      sizeof(cfg->ciph_key[0]) * i);
428 
429 		/* Load up the salt */
430 		cfg->aesgcm_fields.salt = get_unaligned_be32(x->aead->alg_key + key_len);
431 	}
432 
433 	if (x->ealg) {
434 		key_len = DIV_ROUND_UP(x->ealg->alg_key_len, BITS_PER_BYTE);
435 
436 		if (key_len > sizeof(cfg->ciph_key)) {
437 			nn_err(nn, "ealg: Insufficient space for offloaded key\n");
438 			return -EINVAL;
439 		}
440 		for (i = 0; i < key_len / sizeof(cfg->ciph_key[0]) ; i++)
441 			cfg->ciph_key[i] = get_unaligned_be32(x->ealg->alg_key +
442 							      sizeof(cfg->ciph_key[0]) * i);
443 	}
444 
445 	/* IP related info */
446 	switch (x->props.family) {
447 	case AF_INET:
448 		cfg->ipv6 = 0;
449 		cfg->src_ip[0] = ntohl(x->props.saddr.a4);
450 		cfg->dst_ip[0] = ntohl(x->id.daddr.a4);
451 		break;
452 	case AF_INET6:
453 		cfg->ipv6 = 1;
454 		for (i = 0; i < 4; i++) {
455 			cfg->src_ip[i] = ntohl(x->props.saddr.a6[i]);
456 			cfg->dst_ip[i] = ntohl(x->id.daddr.a6[i]);
457 		}
458 		break;
459 	default:
460 		nn_err(nn, "Unsupported address family\n");
461 		return -EINVAL;
462 	}
463 
464 	/* Maximum nic IPsec code could handle. Other limits may apply. */
465 	cfg->pmtu_limit = 0xffff;
466 	cfg->ctrl_word.encap_dsbl = 1;
467 
468 	/* SA direction */
469 	cfg->ctrl_word.dir = x->xso.dir;
470 
471 	/* Find unused SA data*/
472 	err = xa_alloc(&nn->xa_ipsec, &saidx, x,
473 		       XA_LIMIT(0, NFP_NET_IPSEC_MAX_SA_CNT - 1), GFP_KERNEL);
474 	if (err < 0) {
475 		nn_err(nn, "Unable to get sa_data number for IPsec\n");
476 		return err;
477 	}
478 
479 	/* Allocate saidx and commit the SA */
480 	err = nfp_ipsec_cfg_cmd_issue(nn, NFP_IPSEC_CFG_MSSG_ADD_SA, saidx, &msg);
481 	if (err) {
482 		xa_erase(&nn->xa_ipsec, saidx);
483 		nn_err(nn, "Failed to issue IPsec command err ret=%d\n", err);
484 		return err;
485 	}
486 
487 	/* 0 is invalid offload_handle for kernel */
488 	x->xso.offload_handle = saidx + 1;
489 	return 0;
490 }
491 
492 static void nfp_net_xfrm_del_state(struct xfrm_state *x)
493 {
494 	struct net_device *netdev = x->xso.dev;
495 	struct nfp_ipsec_cfg_mssg msg;
496 	struct nfp_net *nn;
497 	int err;
498 
499 	nn = netdev_priv(netdev);
500 	err = nfp_ipsec_cfg_cmd_issue(nn, NFP_IPSEC_CFG_MSSG_INV_SA,
501 				      x->xso.offload_handle - 1, &msg);
502 	if (err)
503 		nn_warn(nn, "Failed to invalidate SA in hardware\n");
504 
505 	xa_erase(&nn->xa_ipsec, x->xso.offload_handle - 1);
506 }
507 
508 static bool nfp_net_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
509 {
510 	if (x->props.family == AF_INET)
511 		/* Offload with IPv4 options is not supported yet */
512 		return ip_hdr(skb)->ihl == 5;
513 
514 	/* Offload with IPv6 extension headers is not support yet */
515 	return !(ipv6_ext_hdr(ipv6_hdr(skb)->nexthdr));
516 }
517 
518 static const struct xfrmdev_ops nfp_net_ipsec_xfrmdev_ops = {
519 	.xdo_dev_state_add = nfp_net_xfrm_add_state,
520 	.xdo_dev_state_delete = nfp_net_xfrm_del_state,
521 	.xdo_dev_offload_ok = nfp_net_ipsec_offload_ok,
522 };
523 
524 void nfp_net_ipsec_init(struct nfp_net *nn)
525 {
526 	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_IPSEC))
527 		return;
528 
529 	xa_init_flags(&nn->xa_ipsec, XA_FLAGS_ALLOC);
530 	nn->dp.netdev->xfrmdev_ops = &nfp_net_ipsec_xfrmdev_ops;
531 }
532 
533 void nfp_net_ipsec_clean(struct nfp_net *nn)
534 {
535 	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_IPSEC))
536 		return;
537 
538 	WARN_ON(!xa_empty(&nn->xa_ipsec));
539 	xa_destroy(&nn->xa_ipsec);
540 }
541 
542 bool nfp_net_ipsec_tx_prep(struct nfp_net_dp *dp, struct sk_buff *skb,
543 			   struct nfp_ipsec_offload *offload_info)
544 {
545 	struct xfrm_offload *xo = xfrm_offload(skb);
546 	struct xfrm_state *x;
547 
548 	x = xfrm_input_state(skb);
549 	if (!x)
550 		return false;
551 
552 	offload_info->seq_hi = xo->seq.hi;
553 	offload_info->seq_low = xo->seq.low;
554 	offload_info->handle = x->xso.offload_handle;
555 
556 	return true;
557 }
558 
559 int nfp_net_ipsec_rx(struct nfp_meta_parsed *meta, struct sk_buff *skb)
560 {
561 	struct net_device *netdev = skb->dev;
562 	struct xfrm_offload *xo;
563 	struct xfrm_state *x;
564 	struct sec_path *sp;
565 	struct nfp_net *nn;
566 	u32 saidx;
567 
568 	nn = netdev_priv(netdev);
569 
570 	saidx = meta->ipsec_saidx - 1;
571 	if (saidx >= NFP_NET_IPSEC_MAX_SA_CNT)
572 		return -EINVAL;
573 
574 	sp = secpath_set(skb);
575 	if (unlikely(!sp))
576 		return -ENOMEM;
577 
578 	xa_lock(&nn->xa_ipsec);
579 	x = xa_load(&nn->xa_ipsec, saidx);
580 	xa_unlock(&nn->xa_ipsec);
581 	if (!x)
582 		return -EINVAL;
583 
584 	xfrm_state_hold(x);
585 	sp->xvec[sp->len++] = x;
586 	sp->olen++;
587 	xo = xfrm_offload(skb);
588 	xo->flags = CRYPTO_DONE;
589 	xo->status = CRYPTO_SUCCESS;
590 
591 	return 0;
592 }
593