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- // SPDX-License-Identifier: GPL-2.0-only
- #define pr_fmt(fmt) "IPsec: " fmt
- #include <crypto/aead.h>
- #include <crypto/authenc.h>
- #include <linux/err.h>
- #include <linux/module.h>
- #include <net/ip.h>
- #include <net/xfrm.h>
- #include <net/esp.h>
- #include <linux/scatterlist.h>
- #include <linux/kernel.h>
- #include <linux/pfkeyv2.h>
- #include <linux/rtnetlink.h>
- #include <linux/slab.h>
- #include <linux/spinlock.h>
- #include <linux/in6.h>
- #include <net/icmp.h>
- #include <net/protocol.h>
- #include <net/udp.h>
- #include <net/tcp.h>
- #include <net/espintcp.h>
- #include <linux/highmem.h>
- struct esp_skb_cb {
- struct xfrm_skb_cb xfrm;
- void *tmp;
- };
- struct esp_output_extra {
- __be32 seqhi;
- u32 esphoff;
- };
- #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
- /*
- * Allocate an AEAD request structure with extra space for SG and IV.
- *
- * For alignment considerations the IV is placed at the front, followed
- * by the request and finally the SG list.
- *
- * TODO: Use spare space in skb for this where possible.
- */
- static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
- {
- unsigned int len;
- len = extralen;
- len += crypto_aead_ivsize(aead);
- if (len) {
- len += crypto_aead_alignmask(aead) &
- ~(crypto_tfm_ctx_alignment() - 1);
- len = ALIGN(len, crypto_tfm_ctx_alignment());
- }
- len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
- len = ALIGN(len, __alignof__(struct scatterlist));
- len += sizeof(struct scatterlist) * nfrags;
- return kmalloc(len, GFP_ATOMIC);
- }
- static inline void *esp_tmp_extra(void *tmp)
- {
- return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
- }
- static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
- {
- return crypto_aead_ivsize(aead) ?
- PTR_ALIGN((u8 *)tmp + extralen,
- crypto_aead_alignmask(aead) + 1) : tmp + extralen;
- }
- static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
- {
- struct aead_request *req;
- req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
- crypto_tfm_ctx_alignment());
- aead_request_set_tfm(req, aead);
- return req;
- }
- static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
- struct aead_request *req)
- {
- return (void *)ALIGN((unsigned long)(req + 1) +
- crypto_aead_reqsize(aead),
- __alignof__(struct scatterlist));
- }
- static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
- {
- struct esp_output_extra *extra = esp_tmp_extra(tmp);
- struct crypto_aead *aead = x->data;
- int extralen = 0;
- u8 *iv;
- struct aead_request *req;
- struct scatterlist *sg;
- if (x->props.flags & XFRM_STATE_ESN)
- extralen += sizeof(*extra);
- extra = esp_tmp_extra(tmp);
- iv = esp_tmp_iv(aead, tmp, extralen);
- req = esp_tmp_req(aead, iv);
- /* Unref skb_frag_pages in the src scatterlist if necessary.
- * Skip the first sg which comes from skb->data.
- */
- if (req->src != req->dst)
- for (sg = sg_next(req->src); sg; sg = sg_next(sg))
- put_page(sg_page(sg));
- }
- #ifdef CONFIG_INET_ESPINTCP
- struct esp_tcp_sk {
- struct sock *sk;
- struct rcu_head rcu;
- };
- static void esp_free_tcp_sk(struct rcu_head *head)
- {
- struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu);
- sock_put(esk->sk);
- kfree(esk);
- }
- static struct sock *esp_find_tcp_sk(struct xfrm_state *x)
- {
- struct xfrm_encap_tmpl *encap = x->encap;
- struct esp_tcp_sk *esk;
- __be16 sport, dport;
- struct sock *nsk;
- struct sock *sk;
- sk = rcu_dereference(x->encap_sk);
- if (sk && sk->sk_state == TCP_ESTABLISHED)
- return sk;
- spin_lock_bh(&x->lock);
- sport = encap->encap_sport;
- dport = encap->encap_dport;
- nsk = rcu_dereference_protected(x->encap_sk,
- lockdep_is_held(&x->lock));
- if (sk && sk == nsk) {
- esk = kmalloc(sizeof(*esk), GFP_ATOMIC);
- if (!esk) {
- spin_unlock_bh(&x->lock);
- return ERR_PTR(-ENOMEM);
- }
- RCU_INIT_POINTER(x->encap_sk, NULL);
- esk->sk = sk;
- call_rcu(&esk->rcu, esp_free_tcp_sk);
- }
- spin_unlock_bh(&x->lock);
- sk = inet_lookup_established(xs_net(x), &tcp_hashinfo, x->id.daddr.a4,
- dport, x->props.saddr.a4, sport, 0);
- if (!sk)
- return ERR_PTR(-ENOENT);
- if (!tcp_is_ulp_esp(sk)) {
- sock_put(sk);
- return ERR_PTR(-EINVAL);
- }
- spin_lock_bh(&x->lock);
- nsk = rcu_dereference_protected(x->encap_sk,
- lockdep_is_held(&x->lock));
- if (encap->encap_sport != sport ||
- encap->encap_dport != dport) {
- sock_put(sk);
- sk = nsk ?: ERR_PTR(-EREMCHG);
- } else if (sk == nsk) {
- sock_put(sk);
- } else {
- rcu_assign_pointer(x->encap_sk, sk);
- }
- spin_unlock_bh(&x->lock);
- return sk;
- }
- static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb)
- {
- struct sock *sk;
- int err;
- rcu_read_lock();
- sk = esp_find_tcp_sk(x);
- err = PTR_ERR_OR_ZERO(sk);
- if (err)
- goto out;
- bh_lock_sock(sk);
- if (sock_owned_by_user(sk))
- err = espintcp_queue_out(sk, skb);
- else
- err = espintcp_push_skb(sk, skb);
- bh_unlock_sock(sk);
- out:
- rcu_read_unlock();
- return err;
- }
- static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk,
- struct sk_buff *skb)
- {
- struct dst_entry *dst = skb_dst(skb);
- struct xfrm_state *x = dst->xfrm;
- return esp_output_tcp_finish(x, skb);
- }
- static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
- {
- int err;
- local_bh_disable();
- err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb);
- local_bh_enable();
- /* EINPROGRESS just happens to do the right thing. It
- * actually means that the skb has been consumed and
- * isn't coming back.
- */
- return err ?: -EINPROGRESS;
- }
- #else
- static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
- {
- kfree_skb(skb);
- return -EOPNOTSUPP;
- }
- #endif
- static void esp_output_done(struct crypto_async_request *base, int err)
- {
- struct sk_buff *skb = base->data;
- struct xfrm_offload *xo = xfrm_offload(skb);
- void *tmp;
- struct xfrm_state *x;
- if (xo && (xo->flags & XFRM_DEV_RESUME)) {
- struct sec_path *sp = skb_sec_path(skb);
- x = sp->xvec[sp->len - 1];
- } else {
- x = skb_dst(skb)->xfrm;
- }
- tmp = ESP_SKB_CB(skb)->tmp;
- esp_ssg_unref(x, tmp);
- kfree(tmp);
- if (xo && (xo->flags & XFRM_DEV_RESUME)) {
- if (err) {
- XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
- kfree_skb(skb);
- return;
- }
- skb_push(skb, skb->data - skb_mac_header(skb));
- secpath_reset(skb);
- xfrm_dev_resume(skb);
- } else {
- if (!err &&
- x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
- esp_output_tail_tcp(x, skb);
- else
- xfrm_output_resume(skb, err);
- }
- }
- /* Move ESP header back into place. */
- static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
- {
- struct ip_esp_hdr *esph = (void *)(skb->data + offset);
- void *tmp = ESP_SKB_CB(skb)->tmp;
- __be32 *seqhi = esp_tmp_extra(tmp);
- esph->seq_no = esph->spi;
- esph->spi = *seqhi;
- }
- static void esp_output_restore_header(struct sk_buff *skb)
- {
- void *tmp = ESP_SKB_CB(skb)->tmp;
- struct esp_output_extra *extra = esp_tmp_extra(tmp);
- esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
- sizeof(__be32));
- }
- static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
- struct xfrm_state *x,
- struct ip_esp_hdr *esph,
- struct esp_output_extra *extra)
- {
- /* For ESN we move the header forward by 4 bytes to
- * accomodate the high bits. We will move it back after
- * encryption.
- */
- if ((x->props.flags & XFRM_STATE_ESN)) {
- __u32 seqhi;
- struct xfrm_offload *xo = xfrm_offload(skb);
- if (xo)
- seqhi = xo->seq.hi;
- else
- seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
- extra->esphoff = (unsigned char *)esph -
- skb_transport_header(skb);
- esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
- extra->seqhi = esph->spi;
- esph->seq_no = htonl(seqhi);
- }
- esph->spi = x->id.spi;
- return esph;
- }
- static void esp_output_done_esn(struct crypto_async_request *base, int err)
- {
- struct sk_buff *skb = base->data;
- esp_output_restore_header(skb);
- esp_output_done(base, err);
- }
- static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb,
- int encap_type,
- struct esp_info *esp,
- __be16 sport,
- __be16 dport)
- {
- struct udphdr *uh;
- __be32 *udpdata32;
- unsigned int len;
- len = skb->len + esp->tailen - skb_transport_offset(skb);
- if (len + sizeof(struct iphdr) > IP_MAX_MTU)
- return ERR_PTR(-EMSGSIZE);
- uh = (struct udphdr *)esp->esph;
- uh->source = sport;
- uh->dest = dport;
- uh->len = htons(len);
- uh->check = 0;
- *skb_mac_header(skb) = IPPROTO_UDP;
- if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
- udpdata32 = (__be32 *)(uh + 1);
- udpdata32[0] = udpdata32[1] = 0;
- return (struct ip_esp_hdr *)(udpdata32 + 2);
- }
- return (struct ip_esp_hdr *)(uh + 1);
- }
- #ifdef CONFIG_INET_ESPINTCP
- static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
- struct sk_buff *skb,
- struct esp_info *esp)
- {
- __be16 *lenp = (void *)esp->esph;
- struct ip_esp_hdr *esph;
- unsigned int len;
- struct sock *sk;
- len = skb->len + esp->tailen - skb_transport_offset(skb);
- if (len > IP_MAX_MTU)
- return ERR_PTR(-EMSGSIZE);
- rcu_read_lock();
- sk = esp_find_tcp_sk(x);
- rcu_read_unlock();
- if (IS_ERR(sk))
- return ERR_CAST(sk);
- *lenp = htons(len);
- esph = (struct ip_esp_hdr *)(lenp + 1);
- return esph;
- }
- #else
- static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
- struct sk_buff *skb,
- struct esp_info *esp)
- {
- return ERR_PTR(-EOPNOTSUPP);
- }
- #endif
- static int esp_output_encap(struct xfrm_state *x, struct sk_buff *skb,
- struct esp_info *esp)
- {
- struct xfrm_encap_tmpl *encap = x->encap;
- struct ip_esp_hdr *esph;
- __be16 sport, dport;
- int encap_type;
- spin_lock_bh(&x->lock);
- sport = encap->encap_sport;
- dport = encap->encap_dport;
- encap_type = encap->encap_type;
- spin_unlock_bh(&x->lock);
- switch (encap_type) {
- default:
- case UDP_ENCAP_ESPINUDP:
- case UDP_ENCAP_ESPINUDP_NON_IKE:
- esph = esp_output_udp_encap(skb, encap_type, esp, sport, dport);
- break;
- case TCP_ENCAP_ESPINTCP:
- esph = esp_output_tcp_encap(x, skb, esp);
- break;
- }
- if (IS_ERR(esph))
- return PTR_ERR(esph);
- esp->esph = esph;
- return 0;
- }
- int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
- {
- u8 *tail;
- int nfrags;
- int esph_offset;
- struct page *page;
- struct sk_buff *trailer;
- int tailen = esp->tailen;
- /* this is non-NULL only with TCP/UDP Encapsulation */
- if (x->encap) {
- int err = esp_output_encap(x, skb, esp);
- if (err < 0)
- return err;
- }
- if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE ||
- ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE)
- goto cow;
- if (!skb_cloned(skb)) {
- if (tailen <= skb_tailroom(skb)) {
- nfrags = 1;
- trailer = skb;
- tail = skb_tail_pointer(trailer);
- goto skip_cow;
- } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
- && !skb_has_frag_list(skb)) {
- int allocsize;
- struct sock *sk = skb->sk;
- struct page_frag *pfrag = &x->xfrag;
- esp->inplace = false;
- allocsize = ALIGN(tailen, L1_CACHE_BYTES);
- spin_lock_bh(&x->lock);
- if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
- spin_unlock_bh(&x->lock);
- goto cow;
- }
- page = pfrag->page;
- get_page(page);
- tail = page_address(page) + pfrag->offset;
- esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
- nfrags = skb_shinfo(skb)->nr_frags;
- __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
- tailen);
- skb_shinfo(skb)->nr_frags = ++nfrags;
- pfrag->offset = pfrag->offset + allocsize;
- spin_unlock_bh(&x->lock);
- nfrags++;
- skb->len += tailen;
- skb->data_len += tailen;
- skb->truesize += tailen;
- if (sk && sk_fullsock(sk))
- refcount_add(tailen, &sk->sk_wmem_alloc);
- goto out;
- }
- }
- cow:
- esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
- nfrags = skb_cow_data(skb, tailen, &trailer);
- if (nfrags < 0)
- goto out;
- tail = skb_tail_pointer(trailer);
- esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
- skip_cow:
- esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
- pskb_put(skb, trailer, tailen);
- out:
- return nfrags;
- }
- EXPORT_SYMBOL_GPL(esp_output_head);
- int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
- {
- u8 *iv;
- int alen;
- void *tmp;
- int ivlen;
- int assoclen;
- int extralen;
- struct page *page;
- struct ip_esp_hdr *esph;
- struct crypto_aead *aead;
- struct aead_request *req;
- struct scatterlist *sg, *dsg;
- struct esp_output_extra *extra;
- int err = -ENOMEM;
- assoclen = sizeof(struct ip_esp_hdr);
- extralen = 0;
- if (x->props.flags & XFRM_STATE_ESN) {
- extralen += sizeof(*extra);
- assoclen += sizeof(__be32);
- }
- aead = x->data;
- alen = crypto_aead_authsize(aead);
- ivlen = crypto_aead_ivsize(aead);
- tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
- if (!tmp)
- goto error;
- extra = esp_tmp_extra(tmp);
- iv = esp_tmp_iv(aead, tmp, extralen);
- req = esp_tmp_req(aead, iv);
- sg = esp_req_sg(aead, req);
- if (esp->inplace)
- dsg = sg;
- else
- dsg = &sg[esp->nfrags];
- esph = esp_output_set_extra(skb, x, esp->esph, extra);
- esp->esph = esph;
- sg_init_table(sg, esp->nfrags);
- err = skb_to_sgvec(skb, sg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + esp->clen + alen);
- if (unlikely(err < 0))
- goto error_free;
- if (!esp->inplace) {
- int allocsize;
- struct page_frag *pfrag = &x->xfrag;
- allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
- spin_lock_bh(&x->lock);
- if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
- spin_unlock_bh(&x->lock);
- goto error_free;
- }
- skb_shinfo(skb)->nr_frags = 1;
- page = pfrag->page;
- get_page(page);
- /* replace page frags in skb with new page */
- __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
- pfrag->offset = pfrag->offset + allocsize;
- spin_unlock_bh(&x->lock);
- sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
- err = skb_to_sgvec(skb, dsg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + esp->clen + alen);
- if (unlikely(err < 0))
- goto error_free;
- }
- if ((x->props.flags & XFRM_STATE_ESN))
- aead_request_set_callback(req, 0, esp_output_done_esn, skb);
- else
- aead_request_set_callback(req, 0, esp_output_done, skb);
- aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
- aead_request_set_ad(req, assoclen);
- memset(iv, 0, ivlen);
- memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
- min(ivlen, 8));
- ESP_SKB_CB(skb)->tmp = tmp;
- err = crypto_aead_encrypt(req);
- switch (err) {
- case -EINPROGRESS:
- goto error;
- case -ENOSPC:
- err = NET_XMIT_DROP;
- break;
- case 0:
- if ((x->props.flags & XFRM_STATE_ESN))
- esp_output_restore_header(skb);
- }
- if (sg != dsg)
- esp_ssg_unref(x, tmp);
- if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
- err = esp_output_tail_tcp(x, skb);
- error_free:
- kfree(tmp);
- error:
- return err;
- }
- EXPORT_SYMBOL_GPL(esp_output_tail);
- static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
- {
- int alen;
- int blksize;
- struct ip_esp_hdr *esph;
- struct crypto_aead *aead;
- struct esp_info esp;
- esp.inplace = true;
- esp.proto = *skb_mac_header(skb);
- *skb_mac_header(skb) = IPPROTO_ESP;
- /* skb is pure payload to encrypt */
- aead = x->data;
- alen = crypto_aead_authsize(aead);
- esp.tfclen = 0;
- if (x->tfcpad) {
- struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
- u32 padto;
- padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
- if (skb->len < padto)
- esp.tfclen = padto - skb->len;
- }
- blksize = ALIGN(crypto_aead_blocksize(aead), 4);
- esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
- esp.plen = esp.clen - skb->len - esp.tfclen;
- esp.tailen = esp.tfclen + esp.plen + alen;
- esp.esph = ip_esp_hdr(skb);
- esp.nfrags = esp_output_head(x, skb, &esp);
- if (esp.nfrags < 0)
- return esp.nfrags;
- esph = esp.esph;
- esph->spi = x->id.spi;
- esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
- esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
- ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
- skb_push(skb, -skb_network_offset(skb));
- return esp_output_tail(x, skb, &esp);
- }
- static inline int esp_remove_trailer(struct sk_buff *skb)
- {
- struct xfrm_state *x = xfrm_input_state(skb);
- struct xfrm_offload *xo = xfrm_offload(skb);
- struct crypto_aead *aead = x->data;
- int alen, hlen, elen;
- int padlen, trimlen;
- __wsum csumdiff;
- u8 nexthdr[2];
- int ret;
- alen = crypto_aead_authsize(aead);
- hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
- elen = skb->len - hlen;
- if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
- ret = xo->proto;
- goto out;
- }
- if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
- BUG();
- ret = -EINVAL;
- padlen = nexthdr[0];
- if (padlen + 2 + alen >= elen) {
- net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
- padlen + 2, elen - alen);
- goto out;
- }
- trimlen = alen + padlen + 2;
- if (skb->ip_summed == CHECKSUM_COMPLETE) {
- csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
- skb->csum = csum_block_sub(skb->csum, csumdiff,
- skb->len - trimlen);
- }
- pskb_trim(skb, skb->len - trimlen);
- ret = nexthdr[1];
- out:
- return ret;
- }
- int esp_input_done2(struct sk_buff *skb, int err)
- {
- const struct iphdr *iph;
- struct xfrm_state *x = xfrm_input_state(skb);
- struct xfrm_offload *xo = xfrm_offload(skb);
- struct crypto_aead *aead = x->data;
- int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
- int ihl;
- if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
- kfree(ESP_SKB_CB(skb)->tmp);
- if (unlikely(err))
- goto out;
- err = esp_remove_trailer(skb);
- if (unlikely(err < 0))
- goto out;
- iph = ip_hdr(skb);
- ihl = iph->ihl * 4;
- if (x->encap) {
- struct xfrm_encap_tmpl *encap = x->encap;
- struct tcphdr *th = (void *)(skb_network_header(skb) + ihl);
- struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
- __be16 source;
- switch (x->encap->encap_type) {
- case TCP_ENCAP_ESPINTCP:
- source = th->source;
- break;
- case UDP_ENCAP_ESPINUDP:
- case UDP_ENCAP_ESPINUDP_NON_IKE:
- source = uh->source;
- break;
- default:
- WARN_ON_ONCE(1);
- err = -EINVAL;
- goto out;
- }
- /*
- * 1) if the NAT-T peer's IP or port changed then
- * advertize the change to the keying daemon.
- * This is an inbound SA, so just compare
- * SRC ports.
- */
- if (iph->saddr != x->props.saddr.a4 ||
- source != encap->encap_sport) {
- xfrm_address_t ipaddr;
- ipaddr.a4 = iph->saddr;
- km_new_mapping(x, &ipaddr, source);
- /* XXX: perhaps add an extra
- * policy check here, to see
- * if we should allow or
- * reject a packet from a
- * different source
- * address/port.
- */
- }
- /*
- * 2) ignore UDP/TCP checksums in case
- * of NAT-T in Transport Mode, or
- * perform other post-processing fixes
- * as per draft-ietf-ipsec-udp-encaps-06,
- * section 3.1.2
- */
- if (x->props.mode == XFRM_MODE_TRANSPORT)
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- }
- skb_pull_rcsum(skb, hlen);
- if (x->props.mode == XFRM_MODE_TUNNEL)
- skb_reset_transport_header(skb);
- else
- skb_set_transport_header(skb, -ihl);
- /* RFC4303: Drop dummy packets without any error */
- if (err == IPPROTO_NONE)
- err = -EINVAL;
- out:
- return err;
- }
- EXPORT_SYMBOL_GPL(esp_input_done2);
- static void esp_input_done(struct crypto_async_request *base, int err)
- {
- struct sk_buff *skb = base->data;
- xfrm_input_resume(skb, esp_input_done2(skb, err));
- }
- static void esp_input_restore_header(struct sk_buff *skb)
- {
- esp_restore_header(skb, 0);
- __skb_pull(skb, 4);
- }
- static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
- {
- struct xfrm_state *x = xfrm_input_state(skb);
- struct ip_esp_hdr *esph;
- /* For ESN we move the header forward by 4 bytes to
- * accomodate the high bits. We will move it back after
- * decryption.
- */
- if ((x->props.flags & XFRM_STATE_ESN)) {
- esph = skb_push(skb, 4);
- *seqhi = esph->spi;
- esph->spi = esph->seq_no;
- esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
- }
- }
- static void esp_input_done_esn(struct crypto_async_request *base, int err)
- {
- struct sk_buff *skb = base->data;
- esp_input_restore_header(skb);
- esp_input_done(base, err);
- }
- /*
- * Note: detecting truncated vs. non-truncated authentication data is very
- * expensive, so we only support truncated data, which is the recommended
- * and common case.
- */
- static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
- {
- struct crypto_aead *aead = x->data;
- struct aead_request *req;
- struct sk_buff *trailer;
- int ivlen = crypto_aead_ivsize(aead);
- int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
- int nfrags;
- int assoclen;
- int seqhilen;
- __be32 *seqhi;
- void *tmp;
- u8 *iv;
- struct scatterlist *sg;
- int err = -EINVAL;
- if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
- goto out;
- if (elen <= 0)
- goto out;
- assoclen = sizeof(struct ip_esp_hdr);
- seqhilen = 0;
- if (x->props.flags & XFRM_STATE_ESN) {
- seqhilen += sizeof(__be32);
- assoclen += seqhilen;
- }
- if (!skb_cloned(skb)) {
- if (!skb_is_nonlinear(skb)) {
- nfrags = 1;
- goto skip_cow;
- } else if (!skb_has_frag_list(skb)) {
- nfrags = skb_shinfo(skb)->nr_frags;
- nfrags++;
- goto skip_cow;
- }
- }
- err = skb_cow_data(skb, 0, &trailer);
- if (err < 0)
- goto out;
- nfrags = err;
- skip_cow:
- err = -ENOMEM;
- tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
- if (!tmp)
- goto out;
- ESP_SKB_CB(skb)->tmp = tmp;
- seqhi = esp_tmp_extra(tmp);
- iv = esp_tmp_iv(aead, tmp, seqhilen);
- req = esp_tmp_req(aead, iv);
- sg = esp_req_sg(aead, req);
- esp_input_set_header(skb, seqhi);
- sg_init_table(sg, nfrags);
- err = skb_to_sgvec(skb, sg, 0, skb->len);
- if (unlikely(err < 0)) {
- kfree(tmp);
- goto out;
- }
- skb->ip_summed = CHECKSUM_NONE;
- if ((x->props.flags & XFRM_STATE_ESN))
- aead_request_set_callback(req, 0, esp_input_done_esn, skb);
- else
- aead_request_set_callback(req, 0, esp_input_done, skb);
- aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
- aead_request_set_ad(req, assoclen);
- err = crypto_aead_decrypt(req);
- if (err == -EINPROGRESS)
- goto out;
- if ((x->props.flags & XFRM_STATE_ESN))
- esp_input_restore_header(skb);
- err = esp_input_done2(skb, err);
- out:
- return err;
- }
- static int esp4_err(struct sk_buff *skb, u32 info)
- {
- struct net *net = dev_net(skb->dev);
- const struct iphdr *iph = (const struct iphdr *)skb->data;
- struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
- struct xfrm_state *x;
- 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(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
- esph->spi, IPPROTO_ESP, AF_INET);
- if (!x)
- return 0;
- if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
- ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP);
- else
- ipv4_redirect(skb, net, 0, IPPROTO_ESP);
- xfrm_state_put(x);
- return 0;
- }
- static void esp_destroy(struct xfrm_state *x)
- {
- struct crypto_aead *aead = x->data;
- if (!aead)
- return;
- crypto_free_aead(aead);
- }
- static int esp_init_aead(struct xfrm_state *x)
- {
- char aead_name[CRYPTO_MAX_ALG_NAME];
- struct crypto_aead *aead;
- int err;
- err = -ENAMETOOLONG;
- if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
- x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
- goto error;
- aead = crypto_alloc_aead(aead_name, 0, 0);
- err = PTR_ERR(aead);
- if (IS_ERR(aead))
- goto error;
- x->data = aead;
- err = crypto_aead_setkey(aead, x->aead->alg_key,
- (x->aead->alg_key_len + 7) / 8);
- if (err)
- goto error;
- err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
- if (err)
- goto error;
- error:
- return err;
- }
- static int esp_init_authenc(struct xfrm_state *x)
- {
- struct crypto_aead *aead;
- struct crypto_authenc_key_param *param;
- struct rtattr *rta;
- char *key;
- char *p;
- char authenc_name[CRYPTO_MAX_ALG_NAME];
- unsigned int keylen;
- int err;
- err = -EINVAL;
- if (!x->ealg)
- goto error;
- err = -ENAMETOOLONG;
- if ((x->props.flags & XFRM_STATE_ESN)) {
- if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
- "%s%sauthencesn(%s,%s)%s",
- x->geniv ?: "", x->geniv ? "(" : "",
- x->aalg ? x->aalg->alg_name : "digest_null",
- x->ealg->alg_name,
- x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
- goto error;
- } else {
- if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
- "%s%sauthenc(%s,%s)%s",
- x->geniv ?: "", x->geniv ? "(" : "",
- x->aalg ? x->aalg->alg_name : "digest_null",
- x->ealg->alg_name,
- x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
- goto error;
- }
- aead = crypto_alloc_aead(authenc_name, 0, 0);
- err = PTR_ERR(aead);
- if (IS_ERR(aead))
- goto error;
- x->data = aead;
- keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
- (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
- err = -ENOMEM;
- key = kmalloc(keylen, GFP_KERNEL);
- if (!key)
- goto error;
- p = key;
- rta = (void *)p;
- rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
- rta->rta_len = RTA_LENGTH(sizeof(*param));
- param = RTA_DATA(rta);
- p += RTA_SPACE(sizeof(*param));
- if (x->aalg) {
- struct xfrm_algo_desc *aalg_desc;
- memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
- p += (x->aalg->alg_key_len + 7) / 8;
- aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
- BUG_ON(!aalg_desc);
- err = -EINVAL;
- if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
- crypto_aead_authsize(aead)) {
- pr_info("ESP: %s digestsize %u != %hu\n",
- x->aalg->alg_name,
- crypto_aead_authsize(aead),
- aalg_desc->uinfo.auth.icv_fullbits / 8);
- goto free_key;
- }
- err = crypto_aead_setauthsize(
- aead, x->aalg->alg_trunc_len / 8);
- if (err)
- goto free_key;
- }
- param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
- memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
- err = crypto_aead_setkey(aead, key, keylen);
- free_key:
- kfree(key);
- error:
- return err;
- }
- static int esp_init_state(struct xfrm_state *x)
- {
- struct crypto_aead *aead;
- u32 align;
- int err;
- x->data = NULL;
- if (x->aead)
- err = esp_init_aead(x);
- else
- err = esp_init_authenc(x);
- if (err)
- goto error;
- aead = x->data;
- x->props.header_len = sizeof(struct ip_esp_hdr) +
- crypto_aead_ivsize(aead);
- if (x->props.mode == XFRM_MODE_TUNNEL)
- x->props.header_len += sizeof(struct iphdr);
- else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
- x->props.header_len += IPV4_BEET_PHMAXLEN;
- if (x->encap) {
- struct xfrm_encap_tmpl *encap = x->encap;
- switch (encap->encap_type) {
- default:
- err = -EINVAL;
- goto error;
- case UDP_ENCAP_ESPINUDP:
- x->props.header_len += sizeof(struct udphdr);
- break;
- case UDP_ENCAP_ESPINUDP_NON_IKE:
- x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
- break;
- #ifdef CONFIG_INET_ESPINTCP
- case TCP_ENCAP_ESPINTCP:
- /* only the length field, TCP encap is done by
- * the socket
- */
- x->props.header_len += 2;
- break;
- #endif
- }
- }
- align = ALIGN(crypto_aead_blocksize(aead), 4);
- x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
- error:
- return err;
- }
- static int esp4_rcv_cb(struct sk_buff *skb, int err)
- {
- return 0;
- }
- static const struct xfrm_type esp_type =
- {
- .description = "ESP4",
- .owner = THIS_MODULE,
- .proto = IPPROTO_ESP,
- .flags = XFRM_TYPE_REPLAY_PROT,
- .init_state = esp_init_state,
- .destructor = esp_destroy,
- .input = esp_input,
- .output = esp_output,
- };
- static struct xfrm4_protocol esp4_protocol = {
- .handler = xfrm4_rcv,
- .input_handler = xfrm_input,
- .cb_handler = esp4_rcv_cb,
- .err_handler = esp4_err,
- .priority = 0,
- };
- static int __init esp4_init(void)
- {
- if (xfrm_register_type(&esp_type, AF_INET) < 0) {
- pr_info("%s: can't add xfrm type\n", __func__);
- return -EAGAIN;
- }
- if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
- pr_info("%s: can't add protocol\n", __func__);
- xfrm_unregister_type(&esp_type, AF_INET);
- return -EAGAIN;
- }
- return 0;
- }
- static void __exit esp4_fini(void)
- {
- if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
- pr_info("%s: can't remove protocol\n", __func__);
- xfrm_unregister_type(&esp_type, AF_INET);
- }
- module_init(esp4_init);
- module_exit(esp4_fini);
- MODULE_LICENSE("GPL");
- MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
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