diff options
Diffstat (limited to 'net/ipv4/ah4.c')
| -rw-r--r-- | net/ipv4/ah4.c | 488 |
1 files changed, 375 insertions, 113 deletions
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c index 035ad2c9e1b..a2afa89513a 100644 --- a/net/ipv4/ah4.c +++ b/net/ipv4/ah4.c @@ -1,21 +1,83 @@ -#include <linux/config.h> +#define pr_fmt(fmt) "IPsec: " fmt + +#include <crypto/hash.h> +#include <linux/err.h> #include <linux/module.h> +#include <linux/slab.h> #include <net/ip.h> #include <net/xfrm.h> #include <net/ah.h> #include <linux/crypto.h> #include <linux/pfkeyv2.h> +#include <linux/scatterlist.h> #include <net/icmp.h> -#include <asm/scatterlist.h> +#include <net/protocol.h> + +struct ah_skb_cb { + struct xfrm_skb_cb xfrm; + void *tmp; +}; + +#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) + +static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, + unsigned int size) +{ + unsigned int len; + + len = size + crypto_ahash_digestsize(ahash) + + (crypto_ahash_alignmask(ahash) & + ~(crypto_tfm_ctx_alignment() - 1)); + + len = ALIGN(len, crypto_tfm_ctx_alignment()); + len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); + len = ALIGN(len, __alignof__(struct scatterlist)); + + len += sizeof(struct scatterlist) * nfrags; + + return kmalloc(len, GFP_ATOMIC); +} + +static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset) +{ + return tmp + offset; +} + +static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, + unsigned int offset) +{ + return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); +} + +static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, + u8 *icv) +{ + struct ahash_request *req; + + req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), + crypto_tfm_ctx_alignment()); + + ahash_request_set_tfm(req, ahash); + + return req; +} + +static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, + struct ahash_request *req) +{ + return (void *)ALIGN((unsigned long)(req + 1) + + crypto_ahash_reqsize(ahash), + __alignof__(struct scatterlist)); +} /* Clear mutable options and find final destination to substitute * into IP header for icv calculation. Options are already checked * for validity, so paranoia is not required. */ -static int ip_clear_mutable_options(struct iphdr *iph, u32 *daddr) +static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr) { - unsigned char * optptr = (unsigned char*)(iph+1); + unsigned char *optptr = (unsigned char *)(iph+1); int l = iph->ihl*4 - sizeof(struct iphdr); int optlen; @@ -34,7 +96,7 @@ static int ip_clear_mutable_options(struct iphdr *iph, u32 *daddr) switch (*optptr) { case IPOPT_SEC: case 0x85: /* Some "Extended Security" crap. */ - case 0x86: /* Another "Commercial Security" crap. */ + case IPOPT_CIPSO: case IPOPT_RA: case 0x80|21: /* RFC1770 */ break; @@ -45,7 +107,7 @@ static int ip_clear_mutable_options(struct iphdr *iph, u32 *daddr) memcpy(daddr, optptr+optlen-4, 4); /* Fall through */ default: - memset(optptr+2, 0, optlen-2); + memset(optptr, 0, optlen); } l -= optlen; optptr += optlen; @@ -53,19 +115,79 @@ static int ip_clear_mutable_options(struct iphdr *iph, u32 *daddr) return 0; } +static void ah_output_done(struct crypto_async_request *base, int err) +{ + u8 *icv; + struct iphdr *iph; + struct sk_buff *skb = base->data; + struct xfrm_state *x = skb_dst(skb)->xfrm; + struct ah_data *ahp = x->data; + struct iphdr *top_iph = ip_hdr(skb); + struct ip_auth_hdr *ah = ip_auth_hdr(skb); + int ihl = ip_hdrlen(skb); + + iph = AH_SKB_CB(skb)->tmp; + icv = ah_tmp_icv(ahp->ahash, iph, ihl); + memcpy(ah->auth_data, icv, ahp->icv_trunc_len); + + top_iph->tos = iph->tos; + top_iph->ttl = iph->ttl; + top_iph->frag_off = iph->frag_off; + if (top_iph->ihl != 5) { + top_iph->daddr = iph->daddr; + memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); + } + + kfree(AH_SKB_CB(skb)->tmp); + xfrm_output_resume(skb, err); +} + static int ah_output(struct xfrm_state *x, struct sk_buff *skb) { int err; + int nfrags; + int ihl; + u8 *icv; + struct sk_buff *trailer; + struct crypto_ahash *ahash; + struct ahash_request *req; + struct scatterlist *sg; struct iphdr *iph, *top_iph; struct ip_auth_hdr *ah; struct ah_data *ahp; - union { - struct iphdr iph; - char buf[60]; - } tmp_iph; + int seqhi_len = 0; + __be32 *seqhi; + int sglists = 0; + struct scatterlist *seqhisg; + + ahp = x->data; + ahash = ahp->ahash; + + if ((err = skb_cow_data(skb, 0, &trailer)) < 0) + goto out; + nfrags = err; + + skb_push(skb, -skb_network_offset(skb)); + ah = ip_auth_hdr(skb); + ihl = ip_hdrlen(skb); - top_iph = skb->nh.iph; - iph = &tmp_iph.iph; + if (x->props.flags & XFRM_STATE_ESN) { + sglists = 1; + seqhi_len = sizeof(*seqhi); + } + err = -ENOMEM; + iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len); + if (!iph) + goto out; + seqhi = (__be32 *)((char *)iph + ihl); + icv = ah_tmp_icv(ahash, seqhi, seqhi_len); + req = ah_tmp_req(ahash, icv); + sg = ah_req_sg(ahash, req); + seqhisg = sg + nfrags; + + memset(ah->auth_data, 0, ahp->icv_trunc_len); + + top_iph = ip_hdr(skb); iph->tos = top_iph->tos; iph->ttl = top_iph->ttl; @@ -76,27 +198,51 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb) memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); err = ip_clear_mutable_options(top_iph, &top_iph->daddr); if (err) - goto error; + goto out_free; } - ah = (struct ip_auth_hdr *)((char *)top_iph+top_iph->ihl*4); - ah->nexthdr = top_iph->protocol; + ah->nexthdr = *skb_mac_header(skb); + *skb_mac_header(skb) = IPPROTO_AH; top_iph->tos = 0; top_iph->tot_len = htons(skb->len); top_iph->frag_off = 0; top_iph->ttl = 0; - top_iph->protocol = IPPROTO_AH; top_iph->check = 0; - ahp = x->data; - ah->hdrlen = (XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + - ahp->icv_trunc_len) >> 2) - 2; + if (x->props.flags & XFRM_STATE_ALIGN4) + ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; + else + ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; ah->reserved = 0; ah->spi = x->id.spi; - ah->seq_no = htonl(++x->replay.oseq); - ahp->icv(ahp, skb, ah->auth_data); + ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); + + sg_init_table(sg, nfrags + sglists); + skb_to_sgvec_nomark(skb, sg, 0, skb->len); + + if (x->props.flags & XFRM_STATE_ESN) { + /* Attach seqhi sg right after packet payload */ + *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); + sg_set_buf(seqhisg, seqhi, seqhi_len); + } + ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); + ahash_request_set_callback(req, 0, ah_output_done, skb); + + AH_SKB_CB(skb)->tmp = iph; + + err = crypto_ahash_digest(req); + if (err) { + if (err == -EINPROGRESS) + goto out; + + if (err == -EBUSY) + err = NET_XMIT_DROP; + goto out_free; + } + + memcpy(ah->auth_data, icv, ahp->icv_trunc_len); top_iph->tos = iph->tos; top_iph->ttl = iph->ttl; @@ -106,156 +252,268 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb) memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); } - ip_send_check(top_iph); +out_free: + kfree(iph); +out: + return err; +} + +static void ah_input_done(struct crypto_async_request *base, int err) +{ + u8 *auth_data; + u8 *icv; + struct iphdr *work_iph; + struct sk_buff *skb = base->data; + struct xfrm_state *x = xfrm_input_state(skb); + struct ah_data *ahp = x->data; + struct ip_auth_hdr *ah = ip_auth_hdr(skb); + int ihl = ip_hdrlen(skb); + int ah_hlen = (ah->hdrlen + 2) << 2; - err = 0; + work_iph = AH_SKB_CB(skb)->tmp; + auth_data = ah_tmp_auth(work_iph, ihl); + icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); -error: - return err; + err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; + if (err) + goto out; + + err = ah->nexthdr; + + skb->network_header += ah_hlen; + memcpy(skb_network_header(skb), work_iph, ihl); + __skb_pull(skb, ah_hlen + ihl); + + if (x->props.mode == XFRM_MODE_TUNNEL) + skb_reset_transport_header(skb); + else + skb_set_transport_header(skb, -ihl); +out: + kfree(AH_SKB_CB(skb)->tmp); + xfrm_input_resume(skb, err); } -static int ah_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb) +static int ah_input(struct xfrm_state *x, struct sk_buff *skb) { int ah_hlen; - struct iphdr *iph; + int ihl; + int nexthdr; + int nfrags; + u8 *auth_data; + u8 *icv; + struct sk_buff *trailer; + struct crypto_ahash *ahash; + struct ahash_request *req; + struct scatterlist *sg; + struct iphdr *iph, *work_iph; struct ip_auth_hdr *ah; struct ah_data *ahp; - char work_buf[60]; + int err = -ENOMEM; + int seqhi_len = 0; + __be32 *seqhi; + int sglists = 0; + struct scatterlist *seqhisg; - if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) + if (!pskb_may_pull(skb, sizeof(*ah))) goto out; - ah = (struct ip_auth_hdr*)skb->data; + ah = (struct ip_auth_hdr *)skb->data; ahp = x->data; + ahash = ahp->ahash; + + nexthdr = ah->nexthdr; ah_hlen = (ah->hdrlen + 2) << 2; - - if (ah_hlen != XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + ahp->icv_full_len) && - ah_hlen != XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + ahp->icv_trunc_len)) - goto out; + + if (x->props.flags & XFRM_STATE_ALIGN4) { + if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) && + ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len)) + goto out; + } else { + if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && + ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) + goto out; + } if (!pskb_may_pull(skb, ah_hlen)) goto out; /* We are going to _remove_ AH header to keep sockets happy, * so... Later this can change. */ - if (skb_cloned(skb) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + if (skb_unclone(skb, GFP_ATOMIC)) goto out; skb->ip_summed = CHECKSUM_NONE; - ah = (struct ip_auth_hdr*)skb->data; - iph = skb->nh.iph; - memcpy(work_buf, iph, iph->ihl*4); + if ((err = skb_cow_data(skb, 0, &trailer)) < 0) + goto out; + nfrags = err; + + ah = (struct ip_auth_hdr *)skb->data; + iph = ip_hdr(skb); + ihl = ip_hdrlen(skb); + + if (x->props.flags & XFRM_STATE_ESN) { + sglists = 1; + seqhi_len = sizeof(*seqhi); + } + + work_iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + + ahp->icv_trunc_len + seqhi_len); + if (!work_iph) + goto out; + + seqhi = (__be32 *)((char *)work_iph + ihl); + auth_data = ah_tmp_auth(seqhi, seqhi_len); + icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); + req = ah_tmp_req(ahash, icv); + sg = ah_req_sg(ahash, req); + seqhisg = sg + nfrags; + + memcpy(work_iph, iph, ihl); + memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); + memset(ah->auth_data, 0, ahp->icv_trunc_len); iph->ttl = 0; iph->tos = 0; iph->frag_off = 0; iph->check = 0; - if (iph->ihl != 5) { - u32 dummy; - if (ip_clear_mutable_options(iph, &dummy)) - goto out; + if (ihl > sizeof(*iph)) { + __be32 dummy; + err = ip_clear_mutable_options(iph, &dummy); + if (err) + goto out_free; } - { - u8 auth_data[MAX_AH_AUTH_LEN]; - - memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); - skb_push(skb, skb->data - skb->nh.raw); - ahp->icv(ahp, skb, ah->auth_data); - if (memcmp(ah->auth_data, auth_data, ahp->icv_trunc_len)) { - x->stats.integrity_failed++; + + skb_push(skb, ihl); + + sg_init_table(sg, nfrags + sglists); + skb_to_sgvec_nomark(skb, sg, 0, skb->len); + + if (x->props.flags & XFRM_STATE_ESN) { + /* Attach seqhi sg right after packet payload */ + *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; + sg_set_buf(seqhisg, seqhi, seqhi_len); + } + ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); + ahash_request_set_callback(req, 0, ah_input_done, skb); + + AH_SKB_CB(skb)->tmp = work_iph; + + err = crypto_ahash_digest(req); + if (err) { + if (err == -EINPROGRESS) goto out; - } + + goto out_free; } - ((struct iphdr*)work_buf)->protocol = ah->nexthdr; - skb->nh.raw = skb_pull(skb, ah_hlen); - memcpy(skb->nh.raw, work_buf, iph->ihl*4); - skb->nh.iph->tot_len = htons(skb->len); - skb_pull(skb, skb->nh.iph->ihl*4); - skb->h.raw = skb->data; - return 0; + err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; + if (err) + goto out_free; + + skb->network_header += ah_hlen; + memcpy(skb_network_header(skb), work_iph, ihl); + __skb_pull(skb, ah_hlen + ihl); + if (x->props.mode == XFRM_MODE_TUNNEL) + skb_reset_transport_header(skb); + else + skb_set_transport_header(skb, -ihl); + err = nexthdr; + +out_free: + kfree (work_iph); out: - return -EINVAL; + return err; } -static void ah4_err(struct sk_buff *skb, u32 info) +static int ah4_err(struct sk_buff *skb, u32 info) { - struct iphdr *iph = (struct iphdr*)skb->data; - struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+(iph->ihl<<2)); + struct net *net = dev_net(skb->dev); + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2)); struct xfrm_state *x; - if (skb->h.icmph->type != ICMP_DEST_UNREACH || - skb->h.icmph->code != ICMP_FRAG_NEEDED) - return; + switch (icmp_hdr(skb)->type) { + case ICMP_DEST_UNREACH: + if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) + return 0; + case ICMP_REDIRECT: + break; + default: + return 0; + } - x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET); + x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, + ah->spi, IPPROTO_AH, AF_INET); if (!x) - return; - printk(KERN_DEBUG "pmtu discovery on SA AH/%08x/%08x\n", - ntohl(ah->spi), ntohl(iph->daddr)); + return 0; + + if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) + ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0); + else + ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0); xfrm_state_put(x); + + return 0; } static int ah_init_state(struct xfrm_state *x) { struct ah_data *ahp = NULL; struct xfrm_algo_desc *aalg_desc; + struct crypto_ahash *ahash; if (!x->aalg) goto error; - /* null auth can use a zero length key */ - if (x->aalg->alg_key_len > 512) - goto error; - if (x->encap) goto error; - ahp = kmalloc(sizeof(*ahp), GFP_KERNEL); - if (ahp == NULL) + ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); + if (!ahp) return -ENOMEM; - memset(ahp, 0, sizeof(*ahp)); + ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); + if (IS_ERR(ahash)) + goto error; - ahp->key = x->aalg->alg_key; - ahp->key_len = (x->aalg->alg_key_len+7)/8; - ahp->tfm = crypto_alloc_tfm(x->aalg->alg_name, 0); - if (!ahp->tfm) + ahp->ahash = ahash; + if (crypto_ahash_setkey(ahash, x->aalg->alg_key, + (x->aalg->alg_key_len + 7) / 8)) goto error; - ahp->icv = ah_hmac_digest; - + /* * Lookup the algorithm description maintained by xfrm_algo, * verify crypto transform properties, and store information * we need for AH processing. This lookup cannot fail here - * after a successful crypto_alloc_tfm(). + * after a successful crypto_alloc_ahash(). */ aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); BUG_ON(!aalg_desc); if (aalg_desc->uinfo.auth.icv_fullbits/8 != - crypto_tfm_alg_digestsize(ahp->tfm)) { - printk(KERN_INFO "AH: %s digestsize %u != %hu\n", - x->aalg->alg_name, crypto_tfm_alg_digestsize(ahp->tfm), - aalg_desc->uinfo.auth.icv_fullbits/8); + crypto_ahash_digestsize(ahash)) { + pr_info("%s: %s digestsize %u != %hu\n", + __func__, x->aalg->alg_name, + crypto_ahash_digestsize(ahash), + aalg_desc->uinfo.auth.icv_fullbits / 8); goto error; } - + ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; - ahp->icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8; - + ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; + BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN); - - ahp->work_icv = kmalloc(ahp->icv_full_len, GFP_KERNEL); - if (!ahp->work_icv) - goto error; - - x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + ahp->icv_trunc_len); - if (x->props.mode) + + if (x->props.flags & XFRM_STATE_ALIGN4) + x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) + + ahp->icv_trunc_len); + else + x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + + ahp->icv_trunc_len); + if (x->props.mode == XFRM_MODE_TUNNEL) x->props.header_len += sizeof(struct iphdr); x->data = ahp; @@ -263,8 +521,7 @@ static int ah_init_state(struct xfrm_state *x) error: if (ahp) { - kfree(ahp->work_icv); - crypto_free_tfm(ahp->tfm); + crypto_free_ahash(ahp->ahash); kfree(ahp); } return -EINVAL; @@ -277,39 +534,43 @@ static void ah_destroy(struct xfrm_state *x) if (!ahp) return; - kfree(ahp->work_icv); - ahp->work_icv = NULL; - crypto_free_tfm(ahp->tfm); - ahp->tfm = NULL; + crypto_free_ahash(ahp->ahash); kfree(ahp); } +static int ah4_rcv_cb(struct sk_buff *skb, int err) +{ + return 0; +} -static struct xfrm_type ah_type = +static const struct xfrm_type ah_type = { .description = "AH4", .owner = THIS_MODULE, .proto = IPPROTO_AH, + .flags = XFRM_TYPE_REPLAY_PROT, .init_state = ah_init_state, .destructor = ah_destroy, .input = ah_input, .output = ah_output }; -static struct net_protocol ah4_protocol = { +static struct xfrm4_protocol ah4_protocol = { .handler = xfrm4_rcv, + .input_handler = xfrm_input, + .cb_handler = ah4_rcv_cb, .err_handler = ah4_err, - .no_policy = 1, + .priority = 0, }; static int __init ah4_init(void) { if (xfrm_register_type(&ah_type, AF_INET) < 0) { - printk(KERN_INFO "ip ah init: can't add xfrm type\n"); + pr_info("%s: can't add xfrm type\n", __func__); return -EAGAIN; } - if (inet_add_protocol(&ah4_protocol, IPPROTO_AH) < 0) { - printk(KERN_INFO "ip ah init: can't add protocol\n"); + if (xfrm4_protocol_register(&ah4_protocol, IPPROTO_AH) < 0) { + pr_info("%s: can't add protocol\n", __func__); xfrm_unregister_type(&ah_type, AF_INET); return -EAGAIN; } @@ -318,12 +579,13 @@ static int __init ah4_init(void) static void __exit ah4_fini(void) { - if (inet_del_protocol(&ah4_protocol, IPPROTO_AH) < 0) - printk(KERN_INFO "ip ah close: can't remove protocol\n"); + if (xfrm4_protocol_deregister(&ah4_protocol, IPPROTO_AH) < 0) + pr_info("%s: can't remove protocol\n", __func__); if (xfrm_unregister_type(&ah_type, AF_INET) < 0) - printk(KERN_INFO "ip ah close: can't remove xfrm type\n"); + pr_info("%s: can't remove xfrm type\n", __func__); } module_init(ah4_init); module_exit(ah4_fini); MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH); |
