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Diffstat (limited to 'net/ipv6/esp6.c')
-rw-r--r--net/ipv6/esp6.c414
1 files changed, 388 insertions, 26 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 11143d039f16..c43592771126 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -26,11 +26,16 @@
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
+#include <net/ip6_checksum.h>
#include <net/ip6_route.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
+#include <net/udp.h>
#include <linux/icmpv6.h>
+#include <net/tcp.h>
+#include <net/espintcp.h>
+#include <net/inet6_hashtables.h>
#include <linux/highmem.h>
@@ -39,6 +44,11 @@ struct esp_skb_cb {
void *tmp;
};
+struct esp_output_extra {
+ __be32 seqhi;
+ u32 esphoff;
+};
+
#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
/*
@@ -72,9 +82,9 @@ static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
return kmalloc(len, GFP_ATOMIC);
}
-static inline __be32 *esp_tmp_seqhi(void *tmp)
+static inline void *esp_tmp_extra(void *tmp)
{
- return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
+ return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
}
static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
@@ -104,16 +114,17 @@ static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
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 seqhilen = 0;
+ int extralen = 0;
u8 *iv;
struct aead_request *req;
struct scatterlist *sg;
if (x->props.flags & XFRM_STATE_ESN)
- seqhilen += sizeof(__be32);
+ extralen += sizeof(*extra);
- iv = esp_tmp_iv(aead, tmp, seqhilen);
+ iv = esp_tmp_iv(aead, tmp, extralen);
req = esp_tmp_req(aead, iv);
/* Unref skb_frag_pages in the src scatterlist if necessary.
@@ -124,6 +135,149 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
put_page(sg_page(sg));
}
+#ifdef CONFIG_INET6_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 *esp6_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 = __inet6_lookup_established(xs_net(x), &tcp_hashinfo, &x->id.daddr.in6,
+ dport, &x->props.saddr.in6, ntohs(sport), 0, 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 = esp6_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_encap_csum(struct sk_buff *skb)
+{
+ /* UDP encap with IPv6 requires a valid checksum */
+ if (*skb_mac_header(skb) == IPPROTO_UDP) {
+ struct udphdr *uh = udp_hdr(skb);
+ struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ int len = ntohs(uh->len);
+ unsigned int offset = skb_transport_offset(skb);
+ __wsum csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+ uh->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ len, IPPROTO_UDP, csum);
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+ }
+}
+
static void esp_output_done(struct crypto_async_request *base, int err)
{
struct sk_buff *skb = base->data;
@@ -143,6 +297,8 @@ static void esp_output_done(struct crypto_async_request *base, int err)
esp_ssg_unref(x, tmp);
kfree(tmp);
+ esp_output_encap_csum(skb);
+
if (xo && (xo->flags & XFRM_DEV_RESUME)) {
if (err) {
XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
@@ -154,7 +310,11 @@ static void esp_output_done(struct crypto_async_request *base, int err)
secpath_reset(skb);
xfrm_dev_resume(skb);
} else {
- xfrm_output_resume(skb, err);
+ if (!err &&
+ x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
+ esp_output_tail_tcp(x, skb);
+ else
+ xfrm_output_resume(skb, err);
}
}
@@ -163,7 +323,7 @@ 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_seqhi(tmp);
+ __be32 *seqhi = esp_tmp_extra(tmp);
esph->seq_no = esph->spi;
esph->spi = *seqhi;
@@ -171,27 +331,36 @@ static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
static void esp_output_restore_header(struct sk_buff *skb)
{
- esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
+ 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_esn(struct sk_buff *skb,
struct xfrm_state *x,
struct ip_esp_hdr *esph,
- __be32 *seqhi)
+ 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);
- esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
- *seqhi = esph->spi;
if (xo)
- esph->seq_no = htonl(xo->seq.hi);
+ seqhi = xo->seq.hi;
else
- esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
+ 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;
@@ -207,15 +376,122 @@ static void esp_output_done_esn(struct crypto_async_request *base, int err)
esp_output_done(base, err);
}
+static struct ip_esp_hdr *esp6_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 > U16_MAX)
+ 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_INET6_ESPINTCP
+static struct ip_esp_hdr *esp6_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 = esp6_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 *esp6_output_tcp_encap(struct xfrm_state *x,
+ struct sk_buff *skb,
+ struct esp_info *esp)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
+
+static int esp6_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 = esp6_output_udp_encap(skb, encap_type, esp, sport, dport);
+ break;
+ case TCP_ENCAP_ESPINTCP:
+ esph = esp6_output_tcp_encap(x, skb, esp);
+ break;
+ }
+
+ if (IS_ERR(esph))
+ return PTR_ERR(esph);
+
+ esp->esph = esph;
+
+ return 0;
+}
+
int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
{
u8 *tail;
u8 *vaddr;
int nfrags;
+ int esph_offset;
struct page *page;
struct sk_buff *trailer;
int tailen = esp->tailen;
+ if (x->encap) {
+ int err = esp6_output_encap(x, skb, esp);
+
+ if (err < 0)
+ return err;
+ }
+
if (!skb_cloned(skb)) {
if (tailen <= skb_tailroom(skb)) {
nfrags = 1;
@@ -274,10 +550,13 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
}
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);
@@ -295,20 +574,20 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
void *tmp;
int ivlen;
int assoclen;
- int seqhilen;
- __be32 *seqhi;
+ int extralen;
struct page *page;
struct ip_esp_hdr *esph;
struct aead_request *req;
struct crypto_aead *aead;
struct scatterlist *sg, *dsg;
+ struct esp_output_extra *extra;
int err = -ENOMEM;
assoclen = sizeof(struct ip_esp_hdr);
- seqhilen = 0;
+ extralen = 0;
if (x->props.flags & XFRM_STATE_ESN) {
- seqhilen += sizeof(__be32);
+ extralen += sizeof(*extra);
assoclen += sizeof(__be32);
}
@@ -316,12 +595,12 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
alen = crypto_aead_authsize(aead);
ivlen = crypto_aead_ivsize(aead);
- tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
+ tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
if (!tmp)
goto error;
- seqhi = esp_tmp_seqhi(tmp);
- iv = esp_tmp_iv(aead, tmp, seqhilen);
+ extra = esp_tmp_extra(tmp);
+ iv = esp_tmp_iv(aead, tmp, extralen);
req = esp_tmp_req(aead, iv);
sg = esp_req_sg(aead, req);
@@ -330,7 +609,8 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
else
dsg = &sg[esp->nfrags];
- esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
+ esph = esp_output_set_esn(skb, x, esp->esph, extra);
+ esp->esph = esph;
sg_init_table(sg, esp->nfrags);
err = skb_to_sgvec(skb, sg,
@@ -394,11 +674,15 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
case 0:
if ((x->props.flags & XFRM_STATE_ESN))
esp_output_restore_header(skb);
+ esp_output_encap_csum(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:
@@ -438,11 +722,13 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
esp.plen = esp.clen - skb->len - esp.tfclen;
esp.tailen = esp.tfclen + esp.plen + alen;
+ esp.esph = ip_esp_hdr(skb);
+
esp.nfrags = esp6_output_head(x, skb, &esp);
if (esp.nfrags < 0)
return esp.nfrags;
- esph = ip_esp_hdr(skb);
+ esph = esp.esph;
esph->spi = x->id.spi;
esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
@@ -517,6 +803,60 @@ int esp6_input_done2(struct sk_buff *skb, int err)
if (unlikely(err < 0))
goto out;
+ if (x->encap) {
+ const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ struct xfrm_encap_tmpl *encap = x->encap;
+ struct udphdr *uh = (void *)(skb_network_header(skb) + hdr_len);
+ struct tcphdr *th = (void *)(skb_network_header(skb) + hdr_len);
+ __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 (!ipv6_addr_equal(&ip6h->saddr, &x->props.saddr.in6) ||
+ source != encap->encap_sport) {
+ xfrm_address_t ipaddr;
+
+ memcpy(&ipaddr.a6, &ip6h->saddr.s6_addr, sizeof(ipaddr.a6));
+ 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_postpull_rcsum(skb, skb_network_header(skb),
skb_network_header_len(skb));
skb_pull_rcsum(skb, hlen);
@@ -632,7 +972,7 @@ skip_cow:
goto out;
ESP_SKB_CB(skb)->tmp = tmp;
- seqhi = esp_tmp_seqhi(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);
@@ -836,9 +1176,6 @@ static int esp6_init_state(struct xfrm_state *x)
u32 align;
int err;
- if (x->encap)
- return -EINVAL;
-
x->data = NULL;
if (x->aead)
@@ -867,6 +1204,30 @@ static int esp6_init_state(struct xfrm_state *x)
break;
}
+ 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_INET6_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);
@@ -893,6 +1254,7 @@ static const struct xfrm_type esp6_type = {
static struct xfrm6_protocol esp6_protocol = {
.handler = xfrm6_rcv,
+ .input_handler = xfrm_input,
.cb_handler = esp6_rcv_cb,
.err_handler = esp6_err,
.priority = 0,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.