1dff3bb06SSteffen Klassert #include <crypto/hash.h> 207d4ee58SHerbert Xu #include <linux/err.h> 31da177e4SLinus Torvalds #include <linux/module.h> 45a0e3ad6STejun Heo #include <linux/slab.h> 51da177e4SLinus Torvalds #include <net/ip.h> 61da177e4SLinus Torvalds #include <net/xfrm.h> 71da177e4SLinus Torvalds #include <net/ah.h> 81da177e4SLinus Torvalds #include <linux/crypto.h> 91da177e4SLinus Torvalds #include <linux/pfkeyv2.h> 10dff3bb06SSteffen Klassert #include <linux/scatterlist.h> 111da177e4SLinus Torvalds #include <net/icmp.h> 1214c85021SArnaldo Carvalho de Melo #include <net/protocol.h> 131da177e4SLinus Torvalds 14dff3bb06SSteffen Klassert struct ah_skb_cb { 15dff3bb06SSteffen Klassert struct xfrm_skb_cb xfrm; 16dff3bb06SSteffen Klassert void *tmp; 17dff3bb06SSteffen Klassert }; 18dff3bb06SSteffen Klassert 19dff3bb06SSteffen Klassert #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) 20dff3bb06SSteffen Klassert 21dff3bb06SSteffen Klassert static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, 22dff3bb06SSteffen Klassert unsigned int size) 23dff3bb06SSteffen Klassert { 24dff3bb06SSteffen Klassert unsigned int len; 25dff3bb06SSteffen Klassert 26dff3bb06SSteffen Klassert len = size + crypto_ahash_digestsize(ahash) + 27dff3bb06SSteffen Klassert (crypto_ahash_alignmask(ahash) & 28dff3bb06SSteffen Klassert ~(crypto_tfm_ctx_alignment() - 1)); 29dff3bb06SSteffen Klassert 30dff3bb06SSteffen Klassert len = ALIGN(len, crypto_tfm_ctx_alignment()); 31dff3bb06SSteffen Klassert 32dff3bb06SSteffen Klassert len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); 33dff3bb06SSteffen Klassert len = ALIGN(len, __alignof__(struct scatterlist)); 34dff3bb06SSteffen Klassert 35dff3bb06SSteffen Klassert len += sizeof(struct scatterlist) * nfrags; 36dff3bb06SSteffen Klassert 37dff3bb06SSteffen Klassert return kmalloc(len, GFP_ATOMIC); 38dff3bb06SSteffen Klassert } 39dff3bb06SSteffen Klassert 40dff3bb06SSteffen Klassert static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset) 41dff3bb06SSteffen Klassert { 42dff3bb06SSteffen Klassert return tmp + offset; 43dff3bb06SSteffen Klassert } 44dff3bb06SSteffen Klassert 45dff3bb06SSteffen Klassert static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, 46dff3bb06SSteffen Klassert unsigned int offset) 47dff3bb06SSteffen Klassert { 48dff3bb06SSteffen Klassert return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); 49dff3bb06SSteffen Klassert } 50dff3bb06SSteffen Klassert 51dff3bb06SSteffen Klassert static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, 52dff3bb06SSteffen Klassert u8 *icv) 53dff3bb06SSteffen Klassert { 54dff3bb06SSteffen Klassert struct ahash_request *req; 55dff3bb06SSteffen Klassert 56dff3bb06SSteffen Klassert req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), 57dff3bb06SSteffen Klassert crypto_tfm_ctx_alignment()); 58dff3bb06SSteffen Klassert 59dff3bb06SSteffen Klassert ahash_request_set_tfm(req, ahash); 60dff3bb06SSteffen Klassert 61dff3bb06SSteffen Klassert return req; 62dff3bb06SSteffen Klassert } 63dff3bb06SSteffen Klassert 64dff3bb06SSteffen Klassert static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, 65dff3bb06SSteffen Klassert struct ahash_request *req) 66dff3bb06SSteffen Klassert { 67dff3bb06SSteffen Klassert return (void *)ALIGN((unsigned long)(req + 1) + 68dff3bb06SSteffen Klassert crypto_ahash_reqsize(ahash), 69dff3bb06SSteffen Klassert __alignof__(struct scatterlist)); 70dff3bb06SSteffen Klassert } 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds /* Clear mutable options and find final destination to substitute 731da177e4SLinus Torvalds * into IP header for icv calculation. Options are already checked 741da177e4SLinus Torvalds * for validity, so paranoia is not required. */ 751da177e4SLinus Torvalds 76b71d1d42SEric Dumazet static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr) 771da177e4SLinus Torvalds { 781da177e4SLinus Torvalds unsigned char * optptr = (unsigned char*)(iph+1); 791da177e4SLinus Torvalds int l = iph->ihl*4 - sizeof(struct iphdr); 801da177e4SLinus Torvalds int optlen; 811da177e4SLinus Torvalds 821da177e4SLinus Torvalds while (l > 0) { 831da177e4SLinus Torvalds switch (*optptr) { 841da177e4SLinus Torvalds case IPOPT_END: 851da177e4SLinus Torvalds return 0; 861da177e4SLinus Torvalds case IPOPT_NOOP: 871da177e4SLinus Torvalds l--; 881da177e4SLinus Torvalds optptr++; 891da177e4SLinus Torvalds continue; 901da177e4SLinus Torvalds } 911da177e4SLinus Torvalds optlen = optptr[1]; 921da177e4SLinus Torvalds if (optlen<2 || optlen>l) 931da177e4SLinus Torvalds return -EINVAL; 941da177e4SLinus Torvalds switch (*optptr) { 951da177e4SLinus Torvalds case IPOPT_SEC: 961da177e4SLinus Torvalds case 0x85: /* Some "Extended Security" crap. */ 9711a03f78SPaul Moore case IPOPT_CIPSO: 981da177e4SLinus Torvalds case IPOPT_RA: 991da177e4SLinus Torvalds case 0x80|21: /* RFC1770 */ 1001da177e4SLinus Torvalds break; 1011da177e4SLinus Torvalds case IPOPT_LSRR: 1021da177e4SLinus Torvalds case IPOPT_SSRR: 1031da177e4SLinus Torvalds if (optlen < 6) 1041da177e4SLinus Torvalds return -EINVAL; 1051da177e4SLinus Torvalds memcpy(daddr, optptr+optlen-4, 4); 1061da177e4SLinus Torvalds /* Fall through */ 1071da177e4SLinus Torvalds default: 10896fe1c02SNick Bowler memset(optptr, 0, optlen); 1091da177e4SLinus Torvalds } 1101da177e4SLinus Torvalds l -= optlen; 1111da177e4SLinus Torvalds optptr += optlen; 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds return 0; 1141da177e4SLinus Torvalds } 1151da177e4SLinus Torvalds 116dff3bb06SSteffen Klassert static void ah_output_done(struct crypto_async_request *base, int err) 117dff3bb06SSteffen Klassert { 118dff3bb06SSteffen Klassert u8 *icv; 119dff3bb06SSteffen Klassert struct iphdr *iph; 120dff3bb06SSteffen Klassert struct sk_buff *skb = base->data; 121dff3bb06SSteffen Klassert struct xfrm_state *x = skb_dst(skb)->xfrm; 122dff3bb06SSteffen Klassert struct ah_data *ahp = x->data; 123dff3bb06SSteffen Klassert struct iphdr *top_iph = ip_hdr(skb); 124dff3bb06SSteffen Klassert struct ip_auth_hdr *ah = ip_auth_hdr(skb); 125dff3bb06SSteffen Klassert int ihl = ip_hdrlen(skb); 126dff3bb06SSteffen Klassert 127dff3bb06SSteffen Klassert iph = AH_SKB_CB(skb)->tmp; 128dff3bb06SSteffen Klassert icv = ah_tmp_icv(ahp->ahash, iph, ihl); 129dff3bb06SSteffen Klassert memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 130dff3bb06SSteffen Klassert 131dff3bb06SSteffen Klassert top_iph->tos = iph->tos; 132dff3bb06SSteffen Klassert top_iph->ttl = iph->ttl; 133dff3bb06SSteffen Klassert top_iph->frag_off = iph->frag_off; 134dff3bb06SSteffen Klassert if (top_iph->ihl != 5) { 135dff3bb06SSteffen Klassert top_iph->daddr = iph->daddr; 136dff3bb06SSteffen Klassert memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); 137dff3bb06SSteffen Klassert } 138dff3bb06SSteffen Klassert 139dff3bb06SSteffen Klassert kfree(AH_SKB_CB(skb)->tmp); 140dff3bb06SSteffen Klassert xfrm_output_resume(skb, err); 141dff3bb06SSteffen Klassert } 142dff3bb06SSteffen Klassert 1431da177e4SLinus Torvalds static int ah_output(struct xfrm_state *x, struct sk_buff *skb) 1441da177e4SLinus Torvalds { 1451da177e4SLinus Torvalds int err; 146dff3bb06SSteffen Klassert int nfrags; 147dff3bb06SSteffen Klassert int ihl; 148dff3bb06SSteffen Klassert u8 *icv; 149dff3bb06SSteffen Klassert struct sk_buff *trailer; 150dff3bb06SSteffen Klassert struct crypto_ahash *ahash; 151dff3bb06SSteffen Klassert struct ahash_request *req; 152dff3bb06SSteffen Klassert struct scatterlist *sg; 1531da177e4SLinus Torvalds struct iphdr *iph, *top_iph; 1541da177e4SLinus Torvalds struct ip_auth_hdr *ah; 1551da177e4SLinus Torvalds struct ah_data *ahp; 156dff3bb06SSteffen Klassert 157dff3bb06SSteffen Klassert ahp = x->data; 158dff3bb06SSteffen Klassert ahash = ahp->ahash; 159dff3bb06SSteffen Klassert 160dff3bb06SSteffen Klassert if ((err = skb_cow_data(skb, 0, &trailer)) < 0) 161dff3bb06SSteffen Klassert goto out; 162dff3bb06SSteffen Klassert nfrags = err; 1631da177e4SLinus Torvalds 1647b277b1aSHerbert Xu skb_push(skb, -skb_network_offset(skb)); 165dff3bb06SSteffen Klassert ah = ip_auth_hdr(skb); 166dff3bb06SSteffen Klassert ihl = ip_hdrlen(skb); 167dff3bb06SSteffen Klassert 168dff3bb06SSteffen Klassert err = -ENOMEM; 169dff3bb06SSteffen Klassert iph = ah_alloc_tmp(ahash, nfrags, ihl); 170dff3bb06SSteffen Klassert if (!iph) 171dff3bb06SSteffen Klassert goto out; 172dff3bb06SSteffen Klassert 173dff3bb06SSteffen Klassert icv = ah_tmp_icv(ahash, iph, ihl); 174dff3bb06SSteffen Klassert req = ah_tmp_req(ahash, icv); 175dff3bb06SSteffen Klassert sg = ah_req_sg(ahash, req); 176dff3bb06SSteffen Klassert 177dff3bb06SSteffen Klassert memset(ah->auth_data, 0, ahp->icv_trunc_len); 178dff3bb06SSteffen Klassert 179eddc9ec5SArnaldo Carvalho de Melo top_iph = ip_hdr(skb); 1801da177e4SLinus Torvalds 1811da177e4SLinus Torvalds iph->tos = top_iph->tos; 1821da177e4SLinus Torvalds iph->ttl = top_iph->ttl; 1831da177e4SLinus Torvalds iph->frag_off = top_iph->frag_off; 1841da177e4SLinus Torvalds 1851da177e4SLinus Torvalds if (top_iph->ihl != 5) { 1861da177e4SLinus Torvalds iph->daddr = top_iph->daddr; 1871da177e4SLinus Torvalds memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); 1881da177e4SLinus Torvalds err = ip_clear_mutable_options(top_iph, &top_iph->daddr); 1891da177e4SLinus Torvalds if (err) 190dff3bb06SSteffen Klassert goto out_free; 1911da177e4SLinus Torvalds } 1921da177e4SLinus Torvalds 19337fedd3aSHerbert Xu ah->nexthdr = *skb_mac_header(skb); 19437fedd3aSHerbert Xu *skb_mac_header(skb) = IPPROTO_AH; 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvalds top_iph->tos = 0; 1971da177e4SLinus Torvalds top_iph->tot_len = htons(skb->len); 1981da177e4SLinus Torvalds top_iph->frag_off = 0; 1991da177e4SLinus Torvalds top_iph->ttl = 0; 2001da177e4SLinus Torvalds top_iph->check = 0; 2011da177e4SLinus Torvalds 202fa9921e4SNicolas Dichtel if (x->props.flags & XFRM_STATE_ALIGN4) 203fa9921e4SNicolas Dichtel ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; 204fa9921e4SNicolas Dichtel else 20587bdc48dSHerbert Xu ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; 2061da177e4SLinus Torvalds 2071da177e4SLinus Torvalds ah->reserved = 0; 2081da177e4SLinus Torvalds ah->spi = x->id.spi; 2091ce3644aSSteffen Klassert ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 210b7c6538cSHerbert Xu 211dff3bb06SSteffen Klassert sg_init_table(sg, nfrags); 212dff3bb06SSteffen Klassert skb_to_sgvec(skb, sg, 0, skb->len); 213b7c6538cSHerbert Xu 214dff3bb06SSteffen Klassert ahash_request_set_crypt(req, sg, icv, skb->len); 215dff3bb06SSteffen Klassert ahash_request_set_callback(req, 0, ah_output_done, skb); 216dff3bb06SSteffen Klassert 217dff3bb06SSteffen Klassert AH_SKB_CB(skb)->tmp = iph; 218dff3bb06SSteffen Klassert 219dff3bb06SSteffen Klassert err = crypto_ahash_digest(req); 220dff3bb06SSteffen Klassert if (err) { 221dff3bb06SSteffen Klassert if (err == -EINPROGRESS) 222dff3bb06SSteffen Klassert goto out; 223dff3bb06SSteffen Klassert 224dff3bb06SSteffen Klassert if (err == -EBUSY) 225dff3bb06SSteffen Klassert err = NET_XMIT_DROP; 226dff3bb06SSteffen Klassert goto out_free; 227dff3bb06SSteffen Klassert } 228dff3bb06SSteffen Klassert 229dff3bb06SSteffen Klassert memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 2301da177e4SLinus Torvalds 2311da177e4SLinus Torvalds top_iph->tos = iph->tos; 2321da177e4SLinus Torvalds top_iph->ttl = iph->ttl; 2331da177e4SLinus Torvalds top_iph->frag_off = iph->frag_off; 2341da177e4SLinus Torvalds if (top_iph->ihl != 5) { 2351da177e4SLinus Torvalds top_iph->daddr = iph->daddr; 2361da177e4SLinus Torvalds memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); 2371da177e4SLinus Torvalds } 2381da177e4SLinus Torvalds 239dff3bb06SSteffen Klassert out_free: 240dff3bb06SSteffen Klassert kfree(iph); 241dff3bb06SSteffen Klassert out: 2421da177e4SLinus Torvalds return err; 2431da177e4SLinus Torvalds } 2441da177e4SLinus Torvalds 245dff3bb06SSteffen Klassert static void ah_input_done(struct crypto_async_request *base, int err) 246dff3bb06SSteffen Klassert { 247dff3bb06SSteffen Klassert u8 *auth_data; 248dff3bb06SSteffen Klassert u8 *icv; 249dff3bb06SSteffen Klassert struct iphdr *work_iph; 250dff3bb06SSteffen Klassert struct sk_buff *skb = base->data; 251dff3bb06SSteffen Klassert struct xfrm_state *x = xfrm_input_state(skb); 252dff3bb06SSteffen Klassert struct ah_data *ahp = x->data; 253dff3bb06SSteffen Klassert struct ip_auth_hdr *ah = ip_auth_hdr(skb); 254dff3bb06SSteffen Klassert int ihl = ip_hdrlen(skb); 255dff3bb06SSteffen Klassert int ah_hlen = (ah->hdrlen + 2) << 2; 256dff3bb06SSteffen Klassert 257dff3bb06SSteffen Klassert work_iph = AH_SKB_CB(skb)->tmp; 258dff3bb06SSteffen Klassert auth_data = ah_tmp_auth(work_iph, ihl); 259dff3bb06SSteffen Klassert icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); 260dff3bb06SSteffen Klassert 261dff3bb06SSteffen Klassert err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; 262dff3bb06SSteffen Klassert if (err) 263dff3bb06SSteffen Klassert goto out; 264dff3bb06SSteffen Klassert 265b7ea81a5SNick Bowler err = ah->nexthdr; 266b7ea81a5SNick Bowler 267dff3bb06SSteffen Klassert skb->network_header += ah_hlen; 268dff3bb06SSteffen Klassert memcpy(skb_network_header(skb), work_iph, ihl); 269dff3bb06SSteffen Klassert __skb_pull(skb, ah_hlen + ihl); 270dff3bb06SSteffen Klassert skb_set_transport_header(skb, -ihl); 271dff3bb06SSteffen Klassert out: 272dff3bb06SSteffen Klassert kfree(AH_SKB_CB(skb)->tmp); 273dff3bb06SSteffen Klassert xfrm_input_resume(skb, err); 274dff3bb06SSteffen Klassert } 275dff3bb06SSteffen Klassert 276e695633eSHerbert Xu static int ah_input(struct xfrm_state *x, struct sk_buff *skb) 2771da177e4SLinus Torvalds { 2781da177e4SLinus Torvalds int ah_hlen; 27931a4ab93SHerbert Xu int ihl; 280631a6698SHerbert Xu int nexthdr; 281dff3bb06SSteffen Klassert int nfrags; 282dff3bb06SSteffen Klassert u8 *auth_data; 283dff3bb06SSteffen Klassert u8 *icv; 284dff3bb06SSteffen Klassert struct sk_buff *trailer; 285dff3bb06SSteffen Klassert struct crypto_ahash *ahash; 286dff3bb06SSteffen Klassert struct ahash_request *req; 287dff3bb06SSteffen Klassert struct scatterlist *sg; 288dff3bb06SSteffen Klassert struct iphdr *iph, *work_iph; 2891da177e4SLinus Torvalds struct ip_auth_hdr *ah; 2901da177e4SLinus Torvalds struct ah_data *ahp; 291dff3bb06SSteffen Klassert int err = -ENOMEM; 2921da177e4SLinus Torvalds 29387bdc48dSHerbert Xu if (!pskb_may_pull(skb, sizeof(*ah))) 2941da177e4SLinus Torvalds goto out; 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds ah = (struct ip_auth_hdr *)skb->data; 2971da177e4SLinus Torvalds ahp = x->data; 298dff3bb06SSteffen Klassert ahash = ahp->ahash; 299dff3bb06SSteffen Klassert 300631a6698SHerbert Xu nexthdr = ah->nexthdr; 3011da177e4SLinus Torvalds ah_hlen = (ah->hdrlen + 2) << 2; 3021da177e4SLinus Torvalds 303fa9921e4SNicolas Dichtel if (x->props.flags & XFRM_STATE_ALIGN4) { 304fa9921e4SNicolas Dichtel if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) && 305fa9921e4SNicolas Dichtel ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len)) 306fa9921e4SNicolas Dichtel goto out; 307fa9921e4SNicolas Dichtel } else { 30887bdc48dSHerbert Xu if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && 30987bdc48dSHerbert Xu ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) 3101da177e4SLinus Torvalds goto out; 311fa9921e4SNicolas Dichtel } 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds if (!pskb_may_pull(skb, ah_hlen)) 3141da177e4SLinus Torvalds goto out; 3151da177e4SLinus Torvalds 3161da177e4SLinus Torvalds /* We are going to _remove_ AH header to keep sockets happy, 3171da177e4SLinus Torvalds * so... Later this can change. */ 3181da177e4SLinus Torvalds if (skb_cloned(skb) && 3191da177e4SLinus Torvalds pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 3201da177e4SLinus Torvalds goto out; 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 3231da177e4SLinus Torvalds 3241da177e4SLinus Torvalds 325dff3bb06SSteffen Klassert if ((err = skb_cow_data(skb, 0, &trailer)) < 0) 326dff3bb06SSteffen Klassert goto out; 327dff3bb06SSteffen Klassert nfrags = err; 328dff3bb06SSteffen Klassert 3294b0ef1f2SDang Hongwu ah = (struct ip_auth_hdr *)skb->data; 3304b0ef1f2SDang Hongwu iph = ip_hdr(skb); 3314b0ef1f2SDang Hongwu ihl = ip_hdrlen(skb); 3324b0ef1f2SDang Hongwu 333dff3bb06SSteffen Klassert work_iph = ah_alloc_tmp(ahash, nfrags, ihl + ahp->icv_trunc_len); 334dff3bb06SSteffen Klassert if (!work_iph) 335dff3bb06SSteffen Klassert goto out; 336dff3bb06SSteffen Klassert 337dff3bb06SSteffen Klassert auth_data = ah_tmp_auth(work_iph, ihl); 338dff3bb06SSteffen Klassert icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); 339dff3bb06SSteffen Klassert req = ah_tmp_req(ahash, icv); 340dff3bb06SSteffen Klassert sg = ah_req_sg(ahash, req); 341dff3bb06SSteffen Klassert 342dff3bb06SSteffen Klassert memcpy(work_iph, iph, ihl); 343dff3bb06SSteffen Klassert memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); 344dff3bb06SSteffen Klassert memset(ah->auth_data, 0, ahp->icv_trunc_len); 3451da177e4SLinus Torvalds 3461da177e4SLinus Torvalds iph->ttl = 0; 3471da177e4SLinus Torvalds iph->tos = 0; 3481da177e4SLinus Torvalds iph->frag_off = 0; 3491da177e4SLinus Torvalds iph->check = 0; 35031a4ab93SHerbert Xu if (ihl > sizeof(*iph)) { 351d5a0a1e3SAl Viro __be32 dummy; 352dff3bb06SSteffen Klassert err = ip_clear_mutable_options(iph, &dummy); 353dff3bb06SSteffen Klassert if (err) 354dff3bb06SSteffen Klassert goto out_free; 3551da177e4SLinus Torvalds } 3560ebea8efSHerbert Xu 35731a4ab93SHerbert Xu skb_push(skb, ihl); 3580ebea8efSHerbert Xu 359dff3bb06SSteffen Klassert sg_init_table(sg, nfrags); 360dff3bb06SSteffen Klassert skb_to_sgvec(skb, sg, 0, skb->len); 361dff3bb06SSteffen Klassert 362dff3bb06SSteffen Klassert ahash_request_set_crypt(req, sg, icv, skb->len); 363dff3bb06SSteffen Klassert ahash_request_set_callback(req, 0, ah_input_done, skb); 364dff3bb06SSteffen Klassert 365dff3bb06SSteffen Klassert AH_SKB_CB(skb)->tmp = work_iph; 366dff3bb06SSteffen Klassert 367dff3bb06SSteffen Klassert err = crypto_ahash_digest(req); 368dff3bb06SSteffen Klassert if (err) { 369dff3bb06SSteffen Klassert if (err == -EINPROGRESS) 3701da177e4SLinus Torvalds goto out; 3710ebea8efSHerbert Xu 372dff3bb06SSteffen Klassert if (err == -EBUSY) 373dff3bb06SSteffen Klassert err = NET_XMIT_DROP; 374dff3bb06SSteffen Klassert goto out_free; 375dff3bb06SSteffen Klassert } 376dff3bb06SSteffen Klassert 377dff3bb06SSteffen Klassert err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; 378dff3bb06SSteffen Klassert if (err) 379dff3bb06SSteffen Klassert goto out_free; 380dff3bb06SSteffen Klassert 381b0e380b1SArnaldo Carvalho de Melo skb->network_header += ah_hlen; 382dff3bb06SSteffen Klassert memcpy(skb_network_header(skb), work_iph, ihl); 38331a4ab93SHerbert Xu __skb_pull(skb, ah_hlen + ihl); 384dff3bb06SSteffen Klassert skb_set_transport_header(skb, -ihl); 3851da177e4SLinus Torvalds 386dff3bb06SSteffen Klassert err = nexthdr; 3871da177e4SLinus Torvalds 388dff3bb06SSteffen Klassert out_free: 389dff3bb06SSteffen Klassert kfree (work_iph); 3901da177e4SLinus Torvalds out: 39107d4ee58SHerbert Xu return err; 3921da177e4SLinus Torvalds } 3931da177e4SLinus Torvalds 3941da177e4SLinus Torvalds static void ah4_err(struct sk_buff *skb, u32 info) 3951da177e4SLinus Torvalds { 3964fb236baSAlexey Dobriyan struct net *net = dev_net(skb->dev); 397b71d1d42SEric Dumazet const struct iphdr *iph = (const struct iphdr *)skb->data; 3981da177e4SLinus Torvalds struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2)); 3991da177e4SLinus Torvalds struct xfrm_state *x; 4001da177e4SLinus Torvalds 40188c7664fSArnaldo Carvalho de Melo if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH || 40288c7664fSArnaldo Carvalho de Melo icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 4031da177e4SLinus Torvalds return; 4041da177e4SLinus Torvalds 405b71d1d42SEric Dumazet x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 406b71d1d42SEric Dumazet ah->spi, IPPROTO_AH, AF_INET); 4071da177e4SLinus Torvalds if (!x) 4081da177e4SLinus Torvalds return; 4091da177e4SLinus Torvalds printk(KERN_DEBUG "pmtu discovery on SA AH/%08x/%08x\n", 4101da177e4SLinus Torvalds ntohl(ah->spi), ntohl(iph->daddr)); 4111da177e4SLinus Torvalds xfrm_state_put(x); 4121da177e4SLinus Torvalds } 4131da177e4SLinus Torvalds 41472cb6962SHerbert Xu static int ah_init_state(struct xfrm_state *x) 4151da177e4SLinus Torvalds { 4161da177e4SLinus Torvalds struct ah_data *ahp = NULL; 4171da177e4SLinus Torvalds struct xfrm_algo_desc *aalg_desc; 418dff3bb06SSteffen Klassert struct crypto_ahash *ahash; 4191da177e4SLinus Torvalds 4201da177e4SLinus Torvalds if (!x->aalg) 4211da177e4SLinus Torvalds goto error; 4221da177e4SLinus Torvalds 4231da177e4SLinus Torvalds if (x->encap) 4241da177e4SLinus Torvalds goto error; 4251da177e4SLinus Torvalds 4260da974f4SPanagiotis Issaris ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); 427dff3bb06SSteffen Klassert if (!ahp) 4281da177e4SLinus Torvalds return -ENOMEM; 4291da177e4SLinus Torvalds 430dff3bb06SSteffen Klassert ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); 431dff3bb06SSteffen Klassert if (IS_ERR(ahash)) 4321da177e4SLinus Torvalds goto error; 43307d4ee58SHerbert Xu 434dff3bb06SSteffen Klassert ahp->ahash = ahash; 435dff3bb06SSteffen Klassert if (crypto_ahash_setkey(ahash, x->aalg->alg_key, 436bc31d3b2SHerbert Xu (x->aalg->alg_key_len + 7) / 8)) 43707d4ee58SHerbert Xu goto error; 4381da177e4SLinus Torvalds 4391da177e4SLinus Torvalds /* 4401da177e4SLinus Torvalds * Lookup the algorithm description maintained by xfrm_algo, 4411da177e4SLinus Torvalds * verify crypto transform properties, and store information 4421da177e4SLinus Torvalds * we need for AH processing. This lookup cannot fail here 443dff3bb06SSteffen Klassert * after a successful crypto_alloc_ahash(). 4441da177e4SLinus Torvalds */ 4451da177e4SLinus Torvalds aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 4461da177e4SLinus Torvalds BUG_ON(!aalg_desc); 4471da177e4SLinus Torvalds 4481da177e4SLinus Torvalds if (aalg_desc->uinfo.auth.icv_fullbits/8 != 449dff3bb06SSteffen Klassert crypto_ahash_digestsize(ahash)) { 4501da177e4SLinus Torvalds printk(KERN_INFO "AH: %s digestsize %u != %hu\n", 451dff3bb06SSteffen Klassert x->aalg->alg_name, crypto_ahash_digestsize(ahash), 4521da177e4SLinus Torvalds aalg_desc->uinfo.auth.icv_fullbits/8); 4531da177e4SLinus Torvalds goto error; 4541da177e4SLinus Torvalds } 4551da177e4SLinus Torvalds 4561da177e4SLinus Torvalds ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; 4578f8a088cSMartin Willi ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; 4581da177e4SLinus Torvalds 4591da177e4SLinus Torvalds BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN); 4601da177e4SLinus Torvalds 461fa9921e4SNicolas Dichtel if (x->props.flags & XFRM_STATE_ALIGN4) 462fa9921e4SNicolas Dichtel x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) + 463fa9921e4SNicolas Dichtel ahp->icv_trunc_len); 464fa9921e4SNicolas Dichtel else 46587bdc48dSHerbert Xu x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + 46687bdc48dSHerbert Xu ahp->icv_trunc_len); 4677e49e6deSMasahide NAKAMURA if (x->props.mode == XFRM_MODE_TUNNEL) 4681da177e4SLinus Torvalds x->props.header_len += sizeof(struct iphdr); 4691da177e4SLinus Torvalds x->data = ahp; 4701da177e4SLinus Torvalds 4711da177e4SLinus Torvalds return 0; 4721da177e4SLinus Torvalds 4731da177e4SLinus Torvalds error: 4741da177e4SLinus Torvalds if (ahp) { 475dff3bb06SSteffen Klassert crypto_free_ahash(ahp->ahash); 4761da177e4SLinus Torvalds kfree(ahp); 4771da177e4SLinus Torvalds } 4781da177e4SLinus Torvalds return -EINVAL; 4791da177e4SLinus Torvalds } 4801da177e4SLinus Torvalds 4811da177e4SLinus Torvalds static void ah_destroy(struct xfrm_state *x) 4821da177e4SLinus Torvalds { 4831da177e4SLinus Torvalds struct ah_data *ahp = x->data; 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds if (!ahp) 4861da177e4SLinus Torvalds return; 4871da177e4SLinus Torvalds 488dff3bb06SSteffen Klassert crypto_free_ahash(ahp->ahash); 4891da177e4SLinus Torvalds kfree(ahp); 4901da177e4SLinus Torvalds } 4911da177e4SLinus Torvalds 4921da177e4SLinus Torvalds 493533cb5b0SEric Dumazet static const struct xfrm_type ah_type = 4941da177e4SLinus Torvalds { 4951da177e4SLinus Torvalds .description = "AH4", 4961da177e4SLinus Torvalds .owner = THIS_MODULE, 4971da177e4SLinus Torvalds .proto = IPPROTO_AH, 498436a0a40SHerbert Xu .flags = XFRM_TYPE_REPLAY_PROT, 4991da177e4SLinus Torvalds .init_state = ah_init_state, 5001da177e4SLinus Torvalds .destructor = ah_destroy, 5011da177e4SLinus Torvalds .input = ah_input, 5021da177e4SLinus Torvalds .output = ah_output 5031da177e4SLinus Torvalds }; 5041da177e4SLinus Torvalds 50532613090SAlexey Dobriyan static const struct net_protocol ah4_protocol = { 5061da177e4SLinus Torvalds .handler = xfrm4_rcv, 5071da177e4SLinus Torvalds .err_handler = ah4_err, 5081da177e4SLinus Torvalds .no_policy = 1, 5094fb236baSAlexey Dobriyan .netns_ok = 1, 5101da177e4SLinus Torvalds }; 5111da177e4SLinus Torvalds 5121da177e4SLinus Torvalds static int __init ah4_init(void) 5131da177e4SLinus Torvalds { 5141da177e4SLinus Torvalds if (xfrm_register_type(&ah_type, AF_INET) < 0) { 5151da177e4SLinus Torvalds printk(KERN_INFO "ip ah init: can't add xfrm type\n"); 5161da177e4SLinus Torvalds return -EAGAIN; 5171da177e4SLinus Torvalds } 5181da177e4SLinus Torvalds if (inet_add_protocol(&ah4_protocol, IPPROTO_AH) < 0) { 5191da177e4SLinus Torvalds printk(KERN_INFO "ip ah init: can't add protocol\n"); 5201da177e4SLinus Torvalds xfrm_unregister_type(&ah_type, AF_INET); 5211da177e4SLinus Torvalds return -EAGAIN; 5221da177e4SLinus Torvalds } 5231da177e4SLinus Torvalds return 0; 5241da177e4SLinus Torvalds } 5251da177e4SLinus Torvalds 5261da177e4SLinus Torvalds static void __exit ah4_fini(void) 5271da177e4SLinus Torvalds { 5281da177e4SLinus Torvalds if (inet_del_protocol(&ah4_protocol, IPPROTO_AH) < 0) 5291da177e4SLinus Torvalds printk(KERN_INFO "ip ah close: can't remove protocol\n"); 5301da177e4SLinus Torvalds if (xfrm_unregister_type(&ah_type, AF_INET) < 0) 5311da177e4SLinus Torvalds printk(KERN_INFO "ip ah close: can't remove xfrm type\n"); 5321da177e4SLinus Torvalds } 5331da177e4SLinus Torvalds 5341da177e4SLinus Torvalds module_init(ah4_init); 5351da177e4SLinus Torvalds module_exit(ah4_fini); 5361da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 537d3d6dd3aSMasahide NAKAMURA MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH); 538