109c434b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2afd46503SJoe Perches #define pr_fmt(fmt) "IPsec: " fmt
3afd46503SJoe Perches
4dff3bb06SSteffen Klassert #include <crypto/hash.h>
5c66218ccSHerbert Xu #include <crypto/utils.h>
607d4ee58SHerbert Xu #include <linux/err.h>
71da177e4SLinus Torvalds #include <linux/module.h>
85a0e3ad6STejun Heo #include <linux/slab.h>
91da177e4SLinus Torvalds #include <net/ip.h>
101da177e4SLinus Torvalds #include <net/xfrm.h>
111da177e4SLinus Torvalds #include <net/ah.h>
121da177e4SLinus Torvalds #include <linux/crypto.h>
131da177e4SLinus Torvalds #include <linux/pfkeyv2.h>
14dff3bb06SSteffen Klassert #include <linux/scatterlist.h>
151da177e4SLinus Torvalds #include <net/icmp.h>
1614c85021SArnaldo Carvalho de Melo #include <net/protocol.h>
171da177e4SLinus Torvalds
18dff3bb06SSteffen Klassert struct ah_skb_cb {
19dff3bb06SSteffen Klassert struct xfrm_skb_cb xfrm;
20dff3bb06SSteffen Klassert void *tmp;
21dff3bb06SSteffen Klassert };
22dff3bb06SSteffen Klassert
23dff3bb06SSteffen Klassert #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
24dff3bb06SSteffen Klassert
ah_alloc_tmp(struct crypto_ahash * ahash,int nfrags,unsigned int size)25dff3bb06SSteffen Klassert static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
26dff3bb06SSteffen Klassert unsigned int size)
27dff3bb06SSteffen Klassert {
28dff3bb06SSteffen Klassert unsigned int len;
29dff3bb06SSteffen Klassert
30e77f5dd7SEric Biggers len = size + crypto_ahash_digestsize(ahash);
31dff3bb06SSteffen Klassert
32dff3bb06SSteffen Klassert len = ALIGN(len, crypto_tfm_ctx_alignment());
33dff3bb06SSteffen Klassert
34dff3bb06SSteffen Klassert len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
35dff3bb06SSteffen Klassert len = ALIGN(len, __alignof__(struct scatterlist));
36dff3bb06SSteffen Klassert
37dff3bb06SSteffen Klassert len += sizeof(struct scatterlist) * nfrags;
38dff3bb06SSteffen Klassert
39dff3bb06SSteffen Klassert return kmalloc(len, GFP_ATOMIC);
40dff3bb06SSteffen Klassert }
41dff3bb06SSteffen Klassert
ah_tmp_auth(void * tmp,unsigned int offset)42dff3bb06SSteffen Klassert static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset)
43dff3bb06SSteffen Klassert {
44dff3bb06SSteffen Klassert return tmp + offset;
45dff3bb06SSteffen Klassert }
46dff3bb06SSteffen Klassert
ah_tmp_icv(void * tmp,unsigned int offset)47e77f5dd7SEric Biggers static inline u8 *ah_tmp_icv(void *tmp, unsigned int offset)
48dff3bb06SSteffen Klassert {
49e77f5dd7SEric Biggers return tmp + offset;
50dff3bb06SSteffen Klassert }
51dff3bb06SSteffen Klassert
ah_tmp_req(struct crypto_ahash * ahash,u8 * icv)52dff3bb06SSteffen Klassert static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
53dff3bb06SSteffen Klassert u8 *icv)
54dff3bb06SSteffen Klassert {
55dff3bb06SSteffen Klassert struct ahash_request *req;
56dff3bb06SSteffen Klassert
57dff3bb06SSteffen Klassert req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
58dff3bb06SSteffen Klassert crypto_tfm_ctx_alignment());
59dff3bb06SSteffen Klassert
60dff3bb06SSteffen Klassert ahash_request_set_tfm(req, ahash);
61dff3bb06SSteffen Klassert
62dff3bb06SSteffen Klassert return req;
63dff3bb06SSteffen Klassert }
64dff3bb06SSteffen Klassert
ah_req_sg(struct crypto_ahash * ahash,struct ahash_request * req)65dff3bb06SSteffen Klassert static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
66dff3bb06SSteffen Klassert struct ahash_request *req)
67dff3bb06SSteffen Klassert {
68dff3bb06SSteffen Klassert return (void *)ALIGN((unsigned long)(req + 1) +
69dff3bb06SSteffen Klassert crypto_ahash_reqsize(ahash),
70dff3bb06SSteffen Klassert __alignof__(struct scatterlist));
71dff3bb06SSteffen Klassert }
721da177e4SLinus Torvalds
731da177e4SLinus Torvalds /* Clear mutable options and find final destination to substitute
741da177e4SLinus Torvalds * into IP header for icv calculation. Options are already checked
751da177e4SLinus Torvalds * for validity, so paranoia is not required. */
761da177e4SLinus Torvalds
ip_clear_mutable_options(const struct iphdr * iph,__be32 * daddr)77b71d1d42SEric Dumazet static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr)
781da177e4SLinus Torvalds {
791da177e4SLinus Torvalds unsigned char *optptr = (unsigned char *)(iph+1);
801da177e4SLinus Torvalds int l = iph->ihl*4 - sizeof(struct iphdr);
811da177e4SLinus Torvalds int optlen;
821da177e4SLinus Torvalds
831da177e4SLinus Torvalds while (l > 0) {
841da177e4SLinus Torvalds switch (*optptr) {
851da177e4SLinus Torvalds case IPOPT_END:
861da177e4SLinus Torvalds return 0;
871da177e4SLinus Torvalds case IPOPT_NOOP:
881da177e4SLinus Torvalds l--;
891da177e4SLinus Torvalds optptr++;
901da177e4SLinus Torvalds continue;
911da177e4SLinus Torvalds }
921da177e4SLinus Torvalds optlen = optptr[1];
931da177e4SLinus Torvalds if (optlen<2 || optlen>l)
941da177e4SLinus Torvalds return -EINVAL;
951da177e4SLinus Torvalds switch (*optptr) {
961da177e4SLinus Torvalds case IPOPT_SEC:
971da177e4SLinus Torvalds case 0x85: /* Some "Extended Security" crap. */
9811a03f78SPaul Moore case IPOPT_CIPSO:
991da177e4SLinus Torvalds case IPOPT_RA:
1001da177e4SLinus Torvalds case 0x80|21: /* RFC1770 */
1011da177e4SLinus Torvalds break;
1021da177e4SLinus Torvalds case IPOPT_LSRR:
1031da177e4SLinus Torvalds case IPOPT_SSRR:
1041da177e4SLinus Torvalds if (optlen < 6)
1051da177e4SLinus Torvalds return -EINVAL;
1061da177e4SLinus Torvalds memcpy(daddr, optptr+optlen-4, 4);
107a8eceea8SJoe Perches fallthrough;
1081da177e4SLinus Torvalds default:
10996fe1c02SNick Bowler memset(optptr, 0, optlen);
1101da177e4SLinus Torvalds }
1111da177e4SLinus Torvalds l -= optlen;
1121da177e4SLinus Torvalds optptr += optlen;
1131da177e4SLinus Torvalds }
1141da177e4SLinus Torvalds return 0;
1151da177e4SLinus Torvalds }
1161da177e4SLinus Torvalds
ah_output_done(void * data,int err)117fd5dabf7SHerbert Xu static void ah_output_done(void *data, int err)
118dff3bb06SSteffen Klassert {
119dff3bb06SSteffen Klassert u8 *icv;
120dff3bb06SSteffen Klassert struct iphdr *iph;
121fd5dabf7SHerbert Xu struct sk_buff *skb = data;
122dff3bb06SSteffen Klassert struct xfrm_state *x = skb_dst(skb)->xfrm;
123dff3bb06SSteffen Klassert struct ah_data *ahp = x->data;
124dff3bb06SSteffen Klassert struct iphdr *top_iph = ip_hdr(skb);
125dff3bb06SSteffen Klassert struct ip_auth_hdr *ah = ip_auth_hdr(skb);
126dff3bb06SSteffen Klassert int ihl = ip_hdrlen(skb);
127dff3bb06SSteffen Klassert
128dff3bb06SSteffen Klassert iph = AH_SKB_CB(skb)->tmp;
129e77f5dd7SEric Biggers icv = ah_tmp_icv(iph, ihl);
130dff3bb06SSteffen Klassert memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
131dff3bb06SSteffen Klassert
132dff3bb06SSteffen Klassert top_iph->tos = iph->tos;
133dff3bb06SSteffen Klassert top_iph->ttl = iph->ttl;
134dff3bb06SSteffen Klassert top_iph->frag_off = iph->frag_off;
135dff3bb06SSteffen Klassert if (top_iph->ihl != 5) {
136dff3bb06SSteffen Klassert top_iph->daddr = iph->daddr;
137dff3bb06SSteffen Klassert memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
138dff3bb06SSteffen Klassert }
139dff3bb06SSteffen Klassert
140dff3bb06SSteffen Klassert kfree(AH_SKB_CB(skb)->tmp);
1419ab1265dSEvan Nimmo xfrm_output_resume(skb->sk, skb, err);
142dff3bb06SSteffen Klassert }
143dff3bb06SSteffen Klassert
ah_output(struct xfrm_state * x,struct sk_buff * skb)1441da177e4SLinus Torvalds static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
1451da177e4SLinus Torvalds {
1461da177e4SLinus Torvalds int err;
147dff3bb06SSteffen Klassert int nfrags;
148dff3bb06SSteffen Klassert int ihl;
149dff3bb06SSteffen Klassert u8 *icv;
150dff3bb06SSteffen Klassert struct sk_buff *trailer;
151dff3bb06SSteffen Klassert struct crypto_ahash *ahash;
152dff3bb06SSteffen Klassert struct ahash_request *req;
153dff3bb06SSteffen Klassert struct scatterlist *sg;
1541da177e4SLinus Torvalds struct iphdr *iph, *top_iph;
1551da177e4SLinus Torvalds struct ip_auth_hdr *ah;
1561da177e4SLinus Torvalds struct ah_data *ahp;
157d4d573d0SFan Du int seqhi_len = 0;
158d4d573d0SFan Du __be32 *seqhi;
159d4d573d0SFan Du int sglists = 0;
160d4d573d0SFan Du struct scatterlist *seqhisg;
161dff3bb06SSteffen Klassert
162dff3bb06SSteffen Klassert ahp = x->data;
163dff3bb06SSteffen Klassert ahash = ahp->ahash;
164dff3bb06SSteffen Klassert
165dff3bb06SSteffen Klassert if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
166dff3bb06SSteffen Klassert goto out;
167dff3bb06SSteffen Klassert nfrags = err;
1681da177e4SLinus Torvalds
1697b277b1aSHerbert Xu skb_push(skb, -skb_network_offset(skb));
170dff3bb06SSteffen Klassert ah = ip_auth_hdr(skb);
171dff3bb06SSteffen Klassert ihl = ip_hdrlen(skb);
172dff3bb06SSteffen Klassert
173d4d573d0SFan Du if (x->props.flags & XFRM_STATE_ESN) {
174d4d573d0SFan Du sglists = 1;
175d4d573d0SFan Du seqhi_len = sizeof(*seqhi);
176d4d573d0SFan Du }
177dff3bb06SSteffen Klassert err = -ENOMEM;
178d4d573d0SFan Du iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len);
179dff3bb06SSteffen Klassert if (!iph)
180dff3bb06SSteffen Klassert goto out;
181d4d573d0SFan Du seqhi = (__be32 *)((char *)iph + ihl);
182e77f5dd7SEric Biggers icv = ah_tmp_icv(seqhi, seqhi_len);
183dff3bb06SSteffen Klassert req = ah_tmp_req(ahash, icv);
184dff3bb06SSteffen Klassert sg = ah_req_sg(ahash, req);
185d4d573d0SFan Du seqhisg = sg + nfrags;
186dff3bb06SSteffen Klassert
187dff3bb06SSteffen Klassert memset(ah->auth_data, 0, ahp->icv_trunc_len);
188dff3bb06SSteffen Klassert
189eddc9ec5SArnaldo Carvalho de Melo top_iph = ip_hdr(skb);
1901da177e4SLinus Torvalds
1911da177e4SLinus Torvalds iph->tos = top_iph->tos;
1921da177e4SLinus Torvalds iph->ttl = top_iph->ttl;
1931da177e4SLinus Torvalds iph->frag_off = top_iph->frag_off;
1941da177e4SLinus Torvalds
1951da177e4SLinus Torvalds if (top_iph->ihl != 5) {
1961da177e4SLinus Torvalds iph->daddr = top_iph->daddr;
1971da177e4SLinus Torvalds memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
1981da177e4SLinus Torvalds err = ip_clear_mutable_options(top_iph, &top_iph->daddr);
1991da177e4SLinus Torvalds if (err)
200dff3bb06SSteffen Klassert goto out_free;
2011da177e4SLinus Torvalds }
2021da177e4SLinus Torvalds
20337fedd3aSHerbert Xu ah->nexthdr = *skb_mac_header(skb);
20437fedd3aSHerbert Xu *skb_mac_header(skb) = IPPROTO_AH;
2051da177e4SLinus Torvalds
2061da177e4SLinus Torvalds top_iph->tos = 0;
2071da177e4SLinus Torvalds top_iph->tot_len = htons(skb->len);
2081da177e4SLinus Torvalds top_iph->frag_off = 0;
2091da177e4SLinus Torvalds top_iph->ttl = 0;
2101da177e4SLinus Torvalds top_iph->check = 0;
2111da177e4SLinus Torvalds
212fa9921e4SNicolas Dichtel if (x->props.flags & XFRM_STATE_ALIGN4)
213fa9921e4SNicolas Dichtel ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
214fa9921e4SNicolas Dichtel else
21587bdc48dSHerbert Xu ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
2161da177e4SLinus Torvalds
2171da177e4SLinus Torvalds ah->reserved = 0;
2181da177e4SLinus Torvalds ah->spi = x->id.spi;
2191ce3644aSSteffen Klassert ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
220b7c6538cSHerbert Xu
221d4d573d0SFan Du sg_init_table(sg, nfrags + sglists);
2223f297707SJason A. Donenfeld err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
2233f297707SJason A. Donenfeld if (unlikely(err < 0))
2243f297707SJason A. Donenfeld goto out_free;
225b7c6538cSHerbert Xu
226d4d573d0SFan Du if (x->props.flags & XFRM_STATE_ESN) {
227d4d573d0SFan Du /* Attach seqhi sg right after packet payload */
228d4d573d0SFan Du *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
229d4d573d0SFan Du sg_set_buf(seqhisg, seqhi, seqhi_len);
230d4d573d0SFan Du }
231d4d573d0SFan Du ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
232dff3bb06SSteffen Klassert ahash_request_set_callback(req, 0, ah_output_done, skb);
233dff3bb06SSteffen Klassert
234dff3bb06SSteffen Klassert AH_SKB_CB(skb)->tmp = iph;
235dff3bb06SSteffen Klassert
236dff3bb06SSteffen Klassert err = crypto_ahash_digest(req);
237dff3bb06SSteffen Klassert if (err) {
238dff3bb06SSteffen Klassert if (err == -EINPROGRESS)
239dff3bb06SSteffen Klassert goto out;
240dff3bb06SSteffen Klassert
241068c2e70SGilad Ben-Yossef if (err == -ENOSPC)
242dff3bb06SSteffen Klassert err = NET_XMIT_DROP;
243dff3bb06SSteffen Klassert goto out_free;
244dff3bb06SSteffen Klassert }
245dff3bb06SSteffen Klassert
246dff3bb06SSteffen Klassert memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
2471da177e4SLinus Torvalds
2481da177e4SLinus Torvalds top_iph->tos = iph->tos;
2491da177e4SLinus Torvalds top_iph->ttl = iph->ttl;
2501da177e4SLinus Torvalds top_iph->frag_off = iph->frag_off;
2511da177e4SLinus Torvalds if (top_iph->ihl != 5) {
2521da177e4SLinus Torvalds top_iph->daddr = iph->daddr;
2531da177e4SLinus Torvalds memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
2541da177e4SLinus Torvalds }
2551da177e4SLinus Torvalds
256dff3bb06SSteffen Klassert out_free:
257dff3bb06SSteffen Klassert kfree(iph);
258dff3bb06SSteffen Klassert out:
2591da177e4SLinus Torvalds return err;
2601da177e4SLinus Torvalds }
2611da177e4SLinus Torvalds
ah_input_done(void * data,int err)262fd5dabf7SHerbert Xu static void ah_input_done(void *data, int err)
263dff3bb06SSteffen Klassert {
264dff3bb06SSteffen Klassert u8 *auth_data;
265dff3bb06SSteffen Klassert u8 *icv;
266dff3bb06SSteffen Klassert struct iphdr *work_iph;
267fd5dabf7SHerbert Xu struct sk_buff *skb = data;
268dff3bb06SSteffen Klassert struct xfrm_state *x = xfrm_input_state(skb);
269dff3bb06SSteffen Klassert struct ah_data *ahp = x->data;
270dff3bb06SSteffen Klassert struct ip_auth_hdr *ah = ip_auth_hdr(skb);
271dff3bb06SSteffen Klassert int ihl = ip_hdrlen(skb);
272dff3bb06SSteffen Klassert int ah_hlen = (ah->hdrlen + 2) << 2;
273dff3bb06SSteffen Klassert
274ebd89a2dSGilad Ben-Yossef if (err)
275ebd89a2dSGilad Ben-Yossef goto out;
276ebd89a2dSGilad Ben-Yossef
277dff3bb06SSteffen Klassert work_iph = AH_SKB_CB(skb)->tmp;
278dff3bb06SSteffen Klassert auth_data = ah_tmp_auth(work_iph, ihl);
279e77f5dd7SEric Biggers icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
280dff3bb06SSteffen Klassert
28167df58a3SSabrina Dubroca err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
282dff3bb06SSteffen Klassert if (err)
283dff3bb06SSteffen Klassert goto out;
284dff3bb06SSteffen Klassert
285b7ea81a5SNick Bowler err = ah->nexthdr;
286b7ea81a5SNick Bowler
287dff3bb06SSteffen Klassert skb->network_header += ah_hlen;
288dff3bb06SSteffen Klassert memcpy(skb_network_header(skb), work_iph, ihl);
289dff3bb06SSteffen Klassert __skb_pull(skb, ah_hlen + ihl);
2907143dfacSLi RongQing
2917143dfacSLi RongQing if (x->props.mode == XFRM_MODE_TUNNEL)
2927143dfacSLi RongQing skb_reset_transport_header(skb);
2937143dfacSLi RongQing else
294dff3bb06SSteffen Klassert skb_set_transport_header(skb, -ihl);
295dff3bb06SSteffen Klassert out:
296dff3bb06SSteffen Klassert kfree(AH_SKB_CB(skb)->tmp);
297dff3bb06SSteffen Klassert xfrm_input_resume(skb, err);
298dff3bb06SSteffen Klassert }
299dff3bb06SSteffen Klassert
ah_input(struct xfrm_state * x,struct sk_buff * skb)300e695633eSHerbert Xu static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
3011da177e4SLinus Torvalds {
3021da177e4SLinus Torvalds int ah_hlen;
30331a4ab93SHerbert Xu int ihl;
304631a6698SHerbert Xu int nexthdr;
305dff3bb06SSteffen Klassert int nfrags;
306dff3bb06SSteffen Klassert u8 *auth_data;
307dff3bb06SSteffen Klassert u8 *icv;
308dff3bb06SSteffen Klassert struct sk_buff *trailer;
309dff3bb06SSteffen Klassert struct crypto_ahash *ahash;
310dff3bb06SSteffen Klassert struct ahash_request *req;
311dff3bb06SSteffen Klassert struct scatterlist *sg;
312dff3bb06SSteffen Klassert struct iphdr *iph, *work_iph;
3131da177e4SLinus Torvalds struct ip_auth_hdr *ah;
3141da177e4SLinus Torvalds struct ah_data *ahp;
315dff3bb06SSteffen Klassert int err = -ENOMEM;
316d8b2a860SFan Du int seqhi_len = 0;
317d8b2a860SFan Du __be32 *seqhi;
318d8b2a860SFan Du int sglists = 0;
319d8b2a860SFan Du struct scatterlist *seqhisg;
3201da177e4SLinus Torvalds
32187bdc48dSHerbert Xu if (!pskb_may_pull(skb, sizeof(*ah)))
3221da177e4SLinus Torvalds goto out;
3231da177e4SLinus Torvalds
3241da177e4SLinus Torvalds ah = (struct ip_auth_hdr *)skb->data;
3251da177e4SLinus Torvalds ahp = x->data;
326dff3bb06SSteffen Klassert ahash = ahp->ahash;
327dff3bb06SSteffen Klassert
328631a6698SHerbert Xu nexthdr = ah->nexthdr;
3291da177e4SLinus Torvalds ah_hlen = (ah->hdrlen + 2) << 2;
3301da177e4SLinus Torvalds
331fa9921e4SNicolas Dichtel if (x->props.flags & XFRM_STATE_ALIGN4) {
332fa9921e4SNicolas Dichtel if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) &&
333fa9921e4SNicolas Dichtel ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len))
334fa9921e4SNicolas Dichtel goto out;
335fa9921e4SNicolas Dichtel } else {
33687bdc48dSHerbert Xu if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
33787bdc48dSHerbert Xu ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
3381da177e4SLinus Torvalds goto out;
339fa9921e4SNicolas Dichtel }
3401da177e4SLinus Torvalds
3411da177e4SLinus Torvalds if (!pskb_may_pull(skb, ah_hlen))
3421da177e4SLinus Torvalds goto out;
3431da177e4SLinus Torvalds
3441da177e4SLinus Torvalds /* We are going to _remove_ AH header to keep sockets happy,
3451da177e4SLinus Torvalds * so... Later this can change. */
34614bbd6a5SPravin B Shelar if (skb_unclone(skb, GFP_ATOMIC))
3471da177e4SLinus Torvalds goto out;
3481da177e4SLinus Torvalds
3491da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE;
3501da177e4SLinus Torvalds
3511da177e4SLinus Torvalds
352dff3bb06SSteffen Klassert if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
353dff3bb06SSteffen Klassert goto out;
354dff3bb06SSteffen Klassert nfrags = err;
355dff3bb06SSteffen Klassert
3564b0ef1f2SDang Hongwu ah = (struct ip_auth_hdr *)skb->data;
3574b0ef1f2SDang Hongwu iph = ip_hdr(skb);
3584b0ef1f2SDang Hongwu ihl = ip_hdrlen(skb);
3594b0ef1f2SDang Hongwu
360d8b2a860SFan Du if (x->props.flags & XFRM_STATE_ESN) {
361d8b2a860SFan Du sglists = 1;
362d8b2a860SFan Du seqhi_len = sizeof(*seqhi);
363d8b2a860SFan Du }
364d8b2a860SFan Du
365d8b2a860SFan Du work_iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl +
366d8b2a860SFan Du ahp->icv_trunc_len + seqhi_len);
36794c10f0eSDavid S. Miller if (!work_iph) {
36894c10f0eSDavid S. Miller err = -ENOMEM;
369dff3bb06SSteffen Klassert goto out;
37094c10f0eSDavid S. Miller }
371dff3bb06SSteffen Klassert
372d8b2a860SFan Du seqhi = (__be32 *)((char *)work_iph + ihl);
373d8b2a860SFan Du auth_data = ah_tmp_auth(seqhi, seqhi_len);
374e77f5dd7SEric Biggers icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
375dff3bb06SSteffen Klassert req = ah_tmp_req(ahash, icv);
376dff3bb06SSteffen Klassert sg = ah_req_sg(ahash, req);
377d8b2a860SFan Du seqhisg = sg + nfrags;
378dff3bb06SSteffen Klassert
379dff3bb06SSteffen Klassert memcpy(work_iph, iph, ihl);
380dff3bb06SSteffen Klassert memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
381dff3bb06SSteffen Klassert memset(ah->auth_data, 0, ahp->icv_trunc_len);
3821da177e4SLinus Torvalds
3831da177e4SLinus Torvalds iph->ttl = 0;
3841da177e4SLinus Torvalds iph->tos = 0;
3851da177e4SLinus Torvalds iph->frag_off = 0;
3861da177e4SLinus Torvalds iph->check = 0;
38731a4ab93SHerbert Xu if (ihl > sizeof(*iph)) {
388d5a0a1e3SAl Viro __be32 dummy;
389dff3bb06SSteffen Klassert err = ip_clear_mutable_options(iph, &dummy);
390dff3bb06SSteffen Klassert if (err)
391dff3bb06SSteffen Klassert goto out_free;
3921da177e4SLinus Torvalds }
3930ebea8efSHerbert Xu
39431a4ab93SHerbert Xu skb_push(skb, ihl);
3950ebea8efSHerbert Xu
396d8b2a860SFan Du sg_init_table(sg, nfrags + sglists);
3973f297707SJason A. Donenfeld err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
3983f297707SJason A. Donenfeld if (unlikely(err < 0))
3993f297707SJason A. Donenfeld goto out_free;
400dff3bb06SSteffen Klassert
401d8b2a860SFan Du if (x->props.flags & XFRM_STATE_ESN) {
402d8b2a860SFan Du /* Attach seqhi sg right after packet payload */
403d8b2a860SFan Du *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
404d8b2a860SFan Du sg_set_buf(seqhisg, seqhi, seqhi_len);
405d8b2a860SFan Du }
406d8b2a860SFan Du ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
407dff3bb06SSteffen Klassert ahash_request_set_callback(req, 0, ah_input_done, skb);
408dff3bb06SSteffen Klassert
409dff3bb06SSteffen Klassert AH_SKB_CB(skb)->tmp = work_iph;
410dff3bb06SSteffen Klassert
411dff3bb06SSteffen Klassert err = crypto_ahash_digest(req);
412dff3bb06SSteffen Klassert if (err) {
413dff3bb06SSteffen Klassert if (err == -EINPROGRESS)
4141da177e4SLinus Torvalds goto out;
4150ebea8efSHerbert Xu
416dff3bb06SSteffen Klassert goto out_free;
417dff3bb06SSteffen Klassert }
418dff3bb06SSteffen Klassert
41967df58a3SSabrina Dubroca err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
420dff3bb06SSteffen Klassert if (err)
421dff3bb06SSteffen Klassert goto out_free;
422dff3bb06SSteffen Klassert
423b0e380b1SArnaldo Carvalho de Melo skb->network_header += ah_hlen;
424dff3bb06SSteffen Klassert memcpy(skb_network_header(skb), work_iph, ihl);
42531a4ab93SHerbert Xu __skb_pull(skb, ah_hlen + ihl);
4267143dfacSLi RongQing if (x->props.mode == XFRM_MODE_TUNNEL)
4277143dfacSLi RongQing skb_reset_transport_header(skb);
4287143dfacSLi RongQing else
429dff3bb06SSteffen Klassert skb_set_transport_header(skb, -ihl);
4301da177e4SLinus Torvalds
431dff3bb06SSteffen Klassert err = nexthdr;
4321da177e4SLinus Torvalds
433dff3bb06SSteffen Klassert out_free:
434dff3bb06SSteffen Klassert kfree (work_iph);
4351da177e4SLinus Torvalds out:
43607d4ee58SHerbert Xu return err;
4371da177e4SLinus Torvalds }
4381da177e4SLinus Torvalds
ah4_err(struct sk_buff * skb,u32 info)439e5b56454SSteffen Klassert static int ah4_err(struct sk_buff *skb, u32 info)
4401da177e4SLinus Torvalds {
4414fb236baSAlexey Dobriyan struct net *net = dev_net(skb->dev);
442b71d1d42SEric Dumazet const struct iphdr *iph = (const struct iphdr *)skb->data;
4431da177e4SLinus Torvalds struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
4441da177e4SLinus Torvalds struct xfrm_state *x;
4451da177e4SLinus Torvalds
44655be7a9cSDavid S. Miller switch (icmp_hdr(skb)->type) {
44755be7a9cSDavid S. Miller case ICMP_DEST_UNREACH:
44855be7a9cSDavid S. Miller if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
449e5b56454SSteffen Klassert return 0;
45079121184SGustavo A. R. Silva break;
45155be7a9cSDavid S. Miller case ICMP_REDIRECT:
45255be7a9cSDavid S. Miller break;
45355be7a9cSDavid S. Miller default:
454e5b56454SSteffen Klassert return 0;
45555be7a9cSDavid S. Miller }
4561da177e4SLinus Torvalds
457b71d1d42SEric Dumazet x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
458b71d1d42SEric Dumazet ah->spi, IPPROTO_AH, AF_INET);
4591da177e4SLinus Torvalds if (!x)
460e5b56454SSteffen Klassert return 0;
46155be7a9cSDavid S. Miller
462387aa65aSTimo Teräs if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
463d888f396SMaciej Żenczykowski ipv4_update_pmtu(skb, net, info, 0, IPPROTO_AH);
464387aa65aSTimo Teräs else
4651042caa7SMaciej Żenczykowski ipv4_redirect(skb, net, 0, IPPROTO_AH);
4661da177e4SLinus Torvalds xfrm_state_put(x);
467e5b56454SSteffen Klassert
468e5b56454SSteffen Klassert return 0;
4691da177e4SLinus Torvalds }
4701da177e4SLinus Torvalds
ah_init_state(struct xfrm_state * x,struct netlink_ext_ack * extack)471e1e10b44SSabrina Dubroca static int ah_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
4721da177e4SLinus Torvalds {
4731da177e4SLinus Torvalds struct ah_data *ahp = NULL;
4741da177e4SLinus Torvalds struct xfrm_algo_desc *aalg_desc;
475dff3bb06SSteffen Klassert struct crypto_ahash *ahash;
4761da177e4SLinus Torvalds
477ef87a4f8SSabrina Dubroca if (!x->aalg) {
478ef87a4f8SSabrina Dubroca NL_SET_ERR_MSG(extack, "AH requires a state with an AUTH algorithm");
4791da177e4SLinus Torvalds goto error;
480ef87a4f8SSabrina Dubroca }
4811da177e4SLinus Torvalds
482ef87a4f8SSabrina Dubroca if (x->encap) {
483ef87a4f8SSabrina Dubroca NL_SET_ERR_MSG(extack, "AH is not compatible with encapsulation");
4841da177e4SLinus Torvalds goto error;
485ef87a4f8SSabrina Dubroca }
4861da177e4SLinus Torvalds
4870da974f4SPanagiotis Issaris ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
488dff3bb06SSteffen Klassert if (!ahp)
4891da177e4SLinus Torvalds return -ENOMEM;
4901da177e4SLinus Torvalds
491dff3bb06SSteffen Klassert ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
492ef87a4f8SSabrina Dubroca if (IS_ERR(ahash)) {
493ef87a4f8SSabrina Dubroca NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
4941da177e4SLinus Torvalds goto error;
495ef87a4f8SSabrina Dubroca }
49607d4ee58SHerbert Xu
497dff3bb06SSteffen Klassert ahp->ahash = ahash;
498dff3bb06SSteffen Klassert if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
499ef87a4f8SSabrina Dubroca (x->aalg->alg_key_len + 7) / 8)) {
500ef87a4f8SSabrina Dubroca NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
50107d4ee58SHerbert Xu goto error;
502ef87a4f8SSabrina Dubroca }
5031da177e4SLinus Torvalds
5041da177e4SLinus Torvalds /*
5051da177e4SLinus Torvalds * Lookup the algorithm description maintained by xfrm_algo,
5061da177e4SLinus Torvalds * verify crypto transform properties, and store information
5071da177e4SLinus Torvalds * we need for AH processing. This lookup cannot fail here
508dff3bb06SSteffen Klassert * after a successful crypto_alloc_ahash().
5091da177e4SLinus Torvalds */
5101da177e4SLinus Torvalds aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
5111da177e4SLinus Torvalds BUG_ON(!aalg_desc);
5121da177e4SLinus Torvalds
5131da177e4SLinus Torvalds if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
514dff3bb06SSteffen Klassert crypto_ahash_digestsize(ahash)) {
515ef87a4f8SSabrina Dubroca NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
5161da177e4SLinus Torvalds goto error;
5171da177e4SLinus Torvalds }
5181da177e4SLinus Torvalds
5191da177e4SLinus Torvalds ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
5208f8a088cSMartin Willi ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
5211da177e4SLinus Torvalds
522fa9921e4SNicolas Dichtel if (x->props.flags & XFRM_STATE_ALIGN4)
523fa9921e4SNicolas Dichtel x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) +
524fa9921e4SNicolas Dichtel ahp->icv_trunc_len);
525fa9921e4SNicolas Dichtel else
52687bdc48dSHerbert Xu x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
52787bdc48dSHerbert Xu ahp->icv_trunc_len);
5287e49e6deSMasahide NAKAMURA if (x->props.mode == XFRM_MODE_TUNNEL)
5291da177e4SLinus Torvalds x->props.header_len += sizeof(struct iphdr);
5301da177e4SLinus Torvalds x->data = ahp;
5311da177e4SLinus Torvalds
5321da177e4SLinus Torvalds return 0;
5331da177e4SLinus Torvalds
5341da177e4SLinus Torvalds error:
5351da177e4SLinus Torvalds if (ahp) {
536dff3bb06SSteffen Klassert crypto_free_ahash(ahp->ahash);
5371da177e4SLinus Torvalds kfree(ahp);
5381da177e4SLinus Torvalds }
5391da177e4SLinus Torvalds return -EINVAL;
5401da177e4SLinus Torvalds }
5411da177e4SLinus Torvalds
ah_destroy(struct xfrm_state * x)5421da177e4SLinus Torvalds static void ah_destroy(struct xfrm_state *x)
5431da177e4SLinus Torvalds {
5441da177e4SLinus Torvalds struct ah_data *ahp = x->data;
5451da177e4SLinus Torvalds
5461da177e4SLinus Torvalds if (!ahp)
5471da177e4SLinus Torvalds return;
5481da177e4SLinus Torvalds
549dff3bb06SSteffen Klassert crypto_free_ahash(ahp->ahash);
5501da177e4SLinus Torvalds kfree(ahp);
5511da177e4SLinus Torvalds }
5521da177e4SLinus Torvalds
ah4_rcv_cb(struct sk_buff * skb,int err)553e5b56454SSteffen Klassert static int ah4_rcv_cb(struct sk_buff *skb, int err)
554e5b56454SSteffen Klassert {
555e5b56454SSteffen Klassert return 0;
556e5b56454SSteffen Klassert }
5571da177e4SLinus Torvalds
558533cb5b0SEric Dumazet static const struct xfrm_type ah_type =
5591da177e4SLinus Torvalds {
5601da177e4SLinus Torvalds .owner = THIS_MODULE,
5611da177e4SLinus Torvalds .proto = IPPROTO_AH,
562436a0a40SHerbert Xu .flags = XFRM_TYPE_REPLAY_PROT,
5631da177e4SLinus Torvalds .init_state = ah_init_state,
5641da177e4SLinus Torvalds .destructor = ah_destroy,
5651da177e4SLinus Torvalds .input = ah_input,
5661da177e4SLinus Torvalds .output = ah_output
5671da177e4SLinus Torvalds };
5681da177e4SLinus Torvalds
569e5b56454SSteffen Klassert static struct xfrm4_protocol ah4_protocol = {
5701da177e4SLinus Torvalds .handler = xfrm4_rcv,
571e5b56454SSteffen Klassert .input_handler = xfrm_input,
572e5b56454SSteffen Klassert .cb_handler = ah4_rcv_cb,
5731da177e4SLinus Torvalds .err_handler = ah4_err,
574e5b56454SSteffen Klassert .priority = 0,
5751da177e4SLinus Torvalds };
5761da177e4SLinus Torvalds
ah4_init(void)5771da177e4SLinus Torvalds static int __init ah4_init(void)
5781da177e4SLinus Torvalds {
5791da177e4SLinus Torvalds if (xfrm_register_type(&ah_type, AF_INET) < 0) {
580058bd4d2SJoe Perches pr_info("%s: can't add xfrm type\n", __func__);
5811da177e4SLinus Torvalds return -EAGAIN;
5821da177e4SLinus Torvalds }
583e5b56454SSteffen Klassert if (xfrm4_protocol_register(&ah4_protocol, IPPROTO_AH) < 0) {
584058bd4d2SJoe Perches pr_info("%s: can't add protocol\n", __func__);
5851da177e4SLinus Torvalds xfrm_unregister_type(&ah_type, AF_INET);
5861da177e4SLinus Torvalds return -EAGAIN;
5871da177e4SLinus Torvalds }
5881da177e4SLinus Torvalds return 0;
5891da177e4SLinus Torvalds }
5901da177e4SLinus Torvalds
ah4_fini(void)5911da177e4SLinus Torvalds static void __exit ah4_fini(void)
5921da177e4SLinus Torvalds {
593e5b56454SSteffen Klassert if (xfrm4_protocol_deregister(&ah4_protocol, IPPROTO_AH) < 0)
594058bd4d2SJoe Perches pr_info("%s: can't remove protocol\n", __func__);
5954f518e80SFlorian Westphal xfrm_unregister_type(&ah_type, AF_INET);
5961da177e4SLinus Torvalds }
5971da177e4SLinus Torvalds
5981da177e4SLinus Torvalds module_init(ah4_init);
5991da177e4SLinus Torvalds module_exit(ah4_fini);
600*b058a5d2SBreno Leitao MODULE_DESCRIPTION("IPv4 AH transformation library");
6011da177e4SLinus Torvalds MODULE_LICENSE("GPL");
602d3d6dd3aSMasahide NAKAMURA MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH);
603