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-rw-r--r--net/ipv6/ah6.c818
1 files changed, 818 insertions, 0 deletions
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
new file mode 100644
index 000000000..2b68bd7c8
--- /dev/null
+++ b/net/ipv6/ah6.c
@@ -0,0 +1,818 @@
+/*
+ * Copyright (C)2002 USAGI/WIDE Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors
+ *
+ * Mitsuru KANDA @USAGI : IPv6 Support
+ * Kazunori MIYAZAWA @USAGI :
+ * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
+ *
+ * This file is derived from net/ipv4/ah.c.
+ */
+
+#define pr_fmt(fmt) "IPv6: " fmt
+
+#include <crypto/algapi.h>
+#include <crypto/hash.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <net/ip.h>
+#include <net/ah.h>
+#include <linux/crypto.h>
+#include <linux/pfkeyv2.h>
+#include <linux/string.h>
+#include <linux/scatterlist.h>
+#include <net/ip6_route.h>
+#include <net/icmp.h>
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/xfrm.h>
+
+#define IPV6HDR_BASELEN 8
+
+struct tmp_ext {
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+ struct in6_addr saddr;
+#endif
+ struct in6_addr daddr;
+ char hdrs[0];
+};
+
+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 struct tmp_ext *ah_tmp_ext(void *base)
+{
+ return base + IPV6HDR_BASELEN;
+}
+
+static inline u8 *ah_tmp_auth(u8 *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));
+}
+
+static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
+{
+ u8 *opt = (u8 *)opthdr;
+ int len = ipv6_optlen(opthdr);
+ int off = 0;
+ int optlen = 0;
+
+ off += 2;
+ len -= 2;
+
+ while (len > 0) {
+
+ switch (opt[off]) {
+
+ case IPV6_TLV_PAD1:
+ optlen = 1;
+ break;
+ default:
+ if (len < 2)
+ goto bad;
+ optlen = opt[off+1]+2;
+ if (len < optlen)
+ goto bad;
+ if (opt[off] & 0x20)
+ memset(&opt[off+2], 0, opt[off+1]);
+ break;
+ }
+
+ off += optlen;
+ len -= optlen;
+ }
+ if (len == 0)
+ return true;
+
+bad:
+ return false;
+}
+
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+/**
+ * ipv6_rearrange_destopt - rearrange IPv6 destination options header
+ * @iph: IPv6 header
+ * @destopt: destionation options header
+ */
+static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
+{
+ u8 *opt = (u8 *)destopt;
+ int len = ipv6_optlen(destopt);
+ int off = 0;
+ int optlen = 0;
+
+ off += 2;
+ len -= 2;
+
+ while (len > 0) {
+
+ switch (opt[off]) {
+
+ case IPV6_TLV_PAD1:
+ optlen = 1;
+ break;
+ default:
+ if (len < 2)
+ goto bad;
+ optlen = opt[off+1]+2;
+ if (len < optlen)
+ goto bad;
+
+ /* Rearrange the source address in @iph and the
+ * addresses in home address option for final source.
+ * See 11.3.2 of RFC 3775 for details.
+ */
+ if (opt[off] == IPV6_TLV_HAO) {
+ struct in6_addr final_addr;
+ struct ipv6_destopt_hao *hao;
+
+ hao = (struct ipv6_destopt_hao *)&opt[off];
+ if (hao->length != sizeof(hao->addr)) {
+ net_warn_ratelimited("destopt hao: invalid header length: %u\n",
+ hao->length);
+ goto bad;
+ }
+ final_addr = hao->addr;
+ hao->addr = iph->saddr;
+ iph->saddr = final_addr;
+ }
+ break;
+ }
+
+ off += optlen;
+ len -= optlen;
+ }
+ /* Note: ok if len == 0 */
+bad:
+ return;
+}
+#else
+static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
+#endif
+
+/**
+ * ipv6_rearrange_rthdr - rearrange IPv6 routing header
+ * @iph: IPv6 header
+ * @rthdr: routing header
+ *
+ * Rearrange the destination address in @iph and the addresses in @rthdr
+ * so that they appear in the order they will at the final destination.
+ * See Appendix A2 of RFC 2402 for details.
+ */
+static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
+{
+ int segments, segments_left;
+ struct in6_addr *addrs;
+ struct in6_addr final_addr;
+
+ segments_left = rthdr->segments_left;
+ if (segments_left == 0)
+ return;
+ rthdr->segments_left = 0;
+
+ /* The value of rthdr->hdrlen has been verified either by the system
+ * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
+ * packets. So we can assume that it is even and that segments is
+ * greater than or equal to segments_left.
+ *
+ * For the same reason we can assume that this option is of type 0.
+ */
+ segments = rthdr->hdrlen >> 1;
+
+ addrs = ((struct rt0_hdr *)rthdr)->addr;
+ final_addr = addrs[segments - 1];
+
+ addrs += segments - segments_left;
+ memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
+
+ addrs[0] = iph->daddr;
+ iph->daddr = final_addr;
+}
+
+static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
+{
+ union {
+ struct ipv6hdr *iph;
+ struct ipv6_opt_hdr *opth;
+ struct ipv6_rt_hdr *rth;
+ char *raw;
+ } exthdr = { .iph = iph };
+ char *end = exthdr.raw + len;
+ int nexthdr = iph->nexthdr;
+
+ exthdr.iph++;
+
+ while (exthdr.raw < end) {
+ switch (nexthdr) {
+ case NEXTHDR_DEST:
+ if (dir == XFRM_POLICY_OUT)
+ ipv6_rearrange_destopt(iph, exthdr.opth);
+ /* fall through */
+ case NEXTHDR_HOP:
+ if (!zero_out_mutable_opts(exthdr.opth)) {
+ net_dbg_ratelimited("overrun %sopts\n",
+ nexthdr == NEXTHDR_HOP ?
+ "hop" : "dest");
+ return -EINVAL;
+ }
+ break;
+
+ case NEXTHDR_ROUTING:
+ ipv6_rearrange_rthdr(iph, exthdr.rth);
+ break;
+
+ default:
+ return 0;
+ }
+
+ nexthdr = exthdr.opth->nexthdr;
+ exthdr.raw += ipv6_optlen(exthdr.opth);
+ }
+
+ return 0;
+}
+
+static void ah6_output_done(struct crypto_async_request *base, int err)
+{
+ int extlen;
+ u8 *iph_base;
+ u8 *icv;
+ struct sk_buff *skb = base->data;
+ struct xfrm_state *x = skb_dst(skb)->xfrm;
+ struct ah_data *ahp = x->data;
+ struct ipv6hdr *top_iph = ipv6_hdr(skb);
+ struct ip_auth_hdr *ah = ip_auth_hdr(skb);
+ struct tmp_ext *iph_ext;
+
+ extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
+ if (extlen)
+ extlen += sizeof(*iph_ext);
+
+ iph_base = AH_SKB_CB(skb)->tmp;
+ iph_ext = ah_tmp_ext(iph_base);
+ icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
+
+ memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
+ memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
+
+ if (extlen) {
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+ memcpy(&top_iph->saddr, iph_ext, extlen);
+#else
+ memcpy(&top_iph->daddr, iph_ext, extlen);
+#endif
+ }
+
+ kfree(AH_SKB_CB(skb)->tmp);
+ xfrm_output_resume(skb, err);
+}
+
+static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+ int nfrags;
+ int extlen;
+ u8 *iph_base;
+ u8 *icv;
+ u8 nexthdr;
+ struct sk_buff *trailer;
+ struct crypto_ahash *ahash;
+ struct ahash_request *req;
+ struct scatterlist *sg;
+ struct ipv6hdr *top_iph;
+ struct ip_auth_hdr *ah;
+ struct ah_data *ahp;
+ struct tmp_ext *iph_ext;
+ int seqhi_len = 0;
+ __be32 *seqhi;
+ int sglists = 0;
+ struct scatterlist *seqhisg;
+
+ ahp = x->data;
+ ahash = ahp->ahash;
+
+ err = skb_cow_data(skb, 0, &trailer);
+ if (err < 0)
+ goto out;
+ nfrags = err;
+
+ skb_push(skb, -skb_network_offset(skb));
+ extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
+ if (extlen)
+ extlen += sizeof(*iph_ext);
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ sglists = 1;
+ seqhi_len = sizeof(*seqhi);
+ }
+ err = -ENOMEM;
+ iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN +
+ extlen + seqhi_len);
+ if (!iph_base)
+ goto out;
+
+ iph_ext = ah_tmp_ext(iph_base);
+ seqhi = (__be32 *)((char *)iph_ext + extlen);
+ icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
+ req = ah_tmp_req(ahash, icv);
+ sg = ah_req_sg(ahash, req);
+ seqhisg = sg + nfrags;
+
+ ah = ip_auth_hdr(skb);
+ memset(ah->auth_data, 0, ahp->icv_trunc_len);
+
+ top_iph = ipv6_hdr(skb);
+ top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
+
+ nexthdr = *skb_mac_header(skb);
+ *skb_mac_header(skb) = IPPROTO_AH;
+
+ /* When there are no extension headers, we only need to save the first
+ * 8 bytes of the base IP header.
+ */
+ memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
+
+ if (extlen) {
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+ memcpy(iph_ext, &top_iph->saddr, extlen);
+#else
+ memcpy(iph_ext, &top_iph->daddr, extlen);
+#endif
+ err = ipv6_clear_mutable_options(top_iph,
+ extlen - sizeof(*iph_ext) +
+ sizeof(*top_iph),
+ XFRM_POLICY_OUT);
+ if (err)
+ goto out_free;
+ }
+
+ ah->nexthdr = nexthdr;
+
+ top_iph->priority = 0;
+ top_iph->flow_lbl[0] = 0;
+ top_iph->flow_lbl[1] = 0;
+ top_iph->flow_lbl[2] = 0;
+ top_iph->hop_limit = 0;
+
+ ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
+
+ ah->reserved = 0;
+ ah->spi = x->id.spi;
+ ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
+
+ sg_init_table(sg, nfrags + sglists);
+ err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out_free;
+
+ 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, ah6_output_done, skb);
+
+ AH_SKB_CB(skb)->tmp = iph_base;
+
+ err = crypto_ahash_digest(req);
+ if (err) {
+ if (err == -EINPROGRESS)
+ goto out;
+
+ if (err == -ENOSPC)
+ err = NET_XMIT_DROP;
+ goto out_free;
+ }
+
+ memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
+ memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
+
+ if (extlen) {
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+ memcpy(&top_iph->saddr, iph_ext, extlen);
+#else
+ memcpy(&top_iph->daddr, iph_ext, extlen);
+#endif
+ }
+
+out_free:
+ kfree(iph_base);
+out:
+ return err;
+}
+
+static void ah6_input_done(struct crypto_async_request *base, int err)
+{
+ u8 *auth_data;
+ u8 *icv;
+ u8 *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 hdr_len = skb_network_header_len(skb);
+ int ah_hlen = (ah->hdrlen + 2) << 2;
+
+ if (err)
+ goto out;
+
+ work_iph = AH_SKB_CB(skb)->tmp;
+ auth_data = ah_tmp_auth(work_iph, hdr_len);
+ icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
+
+ err = crypto_memneq(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, hdr_len);
+ __skb_pull(skb, ah_hlen + hdr_len);
+ if (x->props.mode == XFRM_MODE_TUNNEL)
+ skb_reset_transport_header(skb);
+ else
+ skb_set_transport_header(skb, -hdr_len);
+out:
+ kfree(AH_SKB_CB(skb)->tmp);
+ xfrm_input_resume(skb, err);
+}
+
+
+
+static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ /*
+ * Before process AH
+ * [IPv6][Ext1][Ext2][AH][Dest][Payload]
+ * |<-------------->| hdr_len
+ *
+ * To erase AH:
+ * Keeping copy of cleared headers. After AH processing,
+ * Moving the pointer of skb->network_header by using skb_pull as long
+ * as AH header length. Then copy back the copy as long as hdr_len
+ * If destination header following AH exists, copy it into after [Ext2].
+ *
+ * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
+ * There is offset of AH before IPv6 header after the process.
+ */
+
+ u8 *auth_data;
+ u8 *icv;
+ u8 *work_iph;
+ struct sk_buff *trailer;
+ struct crypto_ahash *ahash;
+ struct ahash_request *req;
+ struct scatterlist *sg;
+ struct ip_auth_hdr *ah;
+ struct ipv6hdr *ip6h;
+ struct ah_data *ahp;
+ u16 hdr_len;
+ u16 ah_hlen;
+ int nexthdr;
+ int nfrags;
+ 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)))
+ goto out;
+
+ /* We are going to _remove_ AH header to keep sockets happy,
+ * so... Later this can change. */
+ if (skb_unclone(skb, GFP_ATOMIC))
+ goto out;
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ hdr_len = skb_network_header_len(skb);
+ 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(*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;
+
+ err = skb_cow_data(skb, 0, &trailer);
+ if (err < 0)
+ goto out;
+ nfrags = err;
+
+ ah = (struct ip_auth_hdr *)skb->data;
+ ip6h = ipv6_hdr(skb);
+
+ skb_push(skb, hdr_len);
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ sglists = 1;
+ seqhi_len = sizeof(*seqhi);
+ }
+
+ work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +
+ ahp->icv_trunc_len + seqhi_len);
+ if (!work_iph) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
+ seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
+ icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
+ req = ah_tmp_req(ahash, icv);
+ sg = ah_req_sg(ahash, req);
+ seqhisg = sg + nfrags;
+
+ memcpy(work_iph, ip6h, hdr_len);
+ memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
+ memset(ah->auth_data, 0, ahp->icv_trunc_len);
+
+ err = ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN);
+ if (err)
+ goto out_free;
+
+ ip6h->priority = 0;
+ ip6h->flow_lbl[0] = 0;
+ ip6h->flow_lbl[1] = 0;
+ ip6h->flow_lbl[2] = 0;
+ ip6h->hop_limit = 0;
+
+ sg_init_table(sg, nfrags + sglists);
+ err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out_free;
+
+ 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, ah6_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;
+ }
+
+ err = crypto_memneq(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, hdr_len);
+ __skb_pull(skb, ah_hlen + hdr_len);
+
+ if (x->props.mode == XFRM_MODE_TUNNEL)
+ skb_reset_transport_header(skb);
+ else
+ skb_set_transport_header(skb, -hdr_len);
+
+ err = nexthdr;
+
+out_free:
+ kfree(work_iph);
+out:
+ return err;
+}
+
+static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ struct net *net = dev_net(skb->dev);
+ struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
+ struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset);
+ struct xfrm_state *x;
+
+ if (type != ICMPV6_PKT_TOOBIG &&
+ type != NDISC_REDIRECT)
+ return 0;
+
+ x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
+ if (!x)
+ return 0;
+
+ if (type == NDISC_REDIRECT)
+ ip6_redirect(skb, net, skb->dev->ifindex, 0,
+ sock_net_uid(net, NULL));
+ else
+ ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
+ xfrm_state_put(x);
+
+ return 0;
+}
+
+static int ah6_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;
+
+ if (x->encap)
+ goto error;
+
+ ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
+ if (!ahp)
+ return -ENOMEM;
+
+ ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
+ if (IS_ERR(ahash))
+ goto error;
+
+ ahp->ahash = ahash;
+ if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
+ (x->aalg->alg_key_len + 7) / 8))
+ goto error;
+
+ /*
+ * 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_hash().
+ */
+ aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
+ BUG_ON(!aalg_desc);
+
+ if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
+ crypto_ahash_digestsize(ahash)) {
+ pr_info("AH: %s digestsize %u != %hu\n",
+ 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 = x->aalg->alg_trunc_len/8;
+
+ x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
+ ahp->icv_trunc_len);
+ switch (x->props.mode) {
+ case XFRM_MODE_BEET:
+ case XFRM_MODE_TRANSPORT:
+ break;
+ case XFRM_MODE_TUNNEL:
+ x->props.header_len += sizeof(struct ipv6hdr);
+ break;
+ default:
+ goto error;
+ }
+ x->data = ahp;
+
+ return 0;
+
+error:
+ if (ahp) {
+ crypto_free_ahash(ahp->ahash);
+ kfree(ahp);
+ }
+ return -EINVAL;
+}
+
+static void ah6_destroy(struct xfrm_state *x)
+{
+ struct ah_data *ahp = x->data;
+
+ if (!ahp)
+ return;
+
+ crypto_free_ahash(ahp->ahash);
+ kfree(ahp);
+}
+
+static int ah6_rcv_cb(struct sk_buff *skb, int err)
+{
+ return 0;
+}
+
+static const struct xfrm_type ah6_type = {
+ .description = "AH6",
+ .owner = THIS_MODULE,
+ .proto = IPPROTO_AH,
+ .flags = XFRM_TYPE_REPLAY_PROT,
+ .init_state = ah6_init_state,
+ .destructor = ah6_destroy,
+ .input = ah6_input,
+ .output = ah6_output,
+ .hdr_offset = xfrm6_find_1stfragopt,
+};
+
+static struct xfrm6_protocol ah6_protocol = {
+ .handler = xfrm6_rcv,
+ .cb_handler = ah6_rcv_cb,
+ .err_handler = ah6_err,
+ .priority = 0,
+};
+
+static int __init ah6_init(void)
+{
+ if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
+ pr_info("%s: can't add xfrm type\n", __func__);
+ return -EAGAIN;
+ }
+
+ if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) {
+ pr_info("%s: can't add protocol\n", __func__);
+ xfrm_unregister_type(&ah6_type, AF_INET6);
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
+static void __exit ah6_fini(void)
+{
+ if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0)
+ pr_info("%s: can't remove protocol\n", __func__);
+
+ if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
+ pr_info("%s: can't remove xfrm type\n", __func__);
+
+}
+
+module_init(ah6_init);
+module_exit(ah6_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 12:50:07 +0000