1 // SPDX-License-Identifier: GPL-2.0
3 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
7 * Kazunori MIYAZAWA @USAGI
8 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
9 * YOSHIFUJI Hideaki @USAGI
13 #include <linux/module.h>
14 #include <linux/string.h>
15 #include <linux/netfilter.h>
16 #include <linux/netfilter_ipv6.h>
20 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
23 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
24 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
25 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
26 return xfrm_input(skb, nexthdr, spi, 0);
28 EXPORT_SYMBOL(xfrm6_rcv_spi);
30 static int xfrm6_transport_finish2(struct net *net, struct sock *sk,
33 if (xfrm_trans_queue(skb, ip6_rcv_finish)) {
41 int xfrm6_transport_finish(struct sk_buff *skb, int async)
43 struct xfrm_offload *xo = xfrm_offload(skb);
44 int nhlen = skb->data - skb_network_header(skb);
46 skb_network_header(skb)[IP6CB(skb)->nhoff] =
47 XFRM_MODE_SKB_CB(skb)->protocol;
49 #ifndef CONFIG_NETFILTER
54 __skb_push(skb, nhlen);
55 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
56 skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
58 if (xo && (xo->flags & XFRM_GRO)) {
59 /* The full l2 header needs to be preserved so that re-injecting the packet at l2
60 * works correctly in the presence of vlan tags.
62 skb_mac_header_rebuild_full(skb, xo->orig_mac_len);
63 skb_reset_network_header(skb);
64 skb_reset_transport_header(skb);
68 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
69 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
70 xfrm6_transport_finish2);
74 /* If it's a keepalive packet, then just eat it.
75 * If it's an encapsulated packet, then pass it to the
77 * Returns 0 if skb passed to xfrm or was dropped.
78 * Returns >0 if skb should be passed to UDP.
79 * Returns <0 if skb should be resubmitted (-ret is protocol)
81 int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
83 struct udp_sock *up = udp_sk(sk);
87 int ip6hlen = sizeof(struct ipv6hdr);
91 __u16 encap_type = up->encap_type;
93 if (skb->protocol == htons(ETH_P_IP))
94 return xfrm4_udp_encap_rcv(sk, skb);
96 /* if this is not encapsulated socket, then just return now */
100 /* If this is a paged skb, make sure we pull up
101 * whatever data we need to look at. */
102 len = skb->len - sizeof(struct udphdr);
103 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
106 /* Now we can get the pointers */
108 udpdata = (__u8 *)uh + sizeof(struct udphdr);
109 udpdata32 = (__be32 *)udpdata;
111 switch (encap_type) {
113 case UDP_ENCAP_ESPINUDP:
114 /* Check if this is a keepalive packet. If so, eat it. */
115 if (len == 1 && udpdata[0] == 0xff) {
117 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
118 /* ESP Packet without Non-ESP header */
119 len = sizeof(struct udphdr);
121 /* Must be an IKE packet.. pass it through */
124 case UDP_ENCAP_ESPINUDP_NON_IKE:
125 /* Check if this is a keepalive packet. If so, eat it. */
126 if (len == 1 && udpdata[0] == 0xff) {
128 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
129 udpdata32[0] == 0 && udpdata32[1] == 0) {
131 /* ESP Packet with Non-IKE marker */
132 len = sizeof(struct udphdr) + 2 * sizeof(u32);
134 /* Must be an IKE packet.. pass it through */
139 /* At this point we are sure that this is an ESPinUDP packet,
140 * so we need to remove 'len' bytes from the packet (the UDP
141 * header and optional ESP marker bytes) and then modify the
142 * protocol to ESP, and then call into the transform receiver.
144 if (skb_unclone(skb, GFP_ATOMIC))
147 /* Now we can update and verify the packet length... */
148 ip6h = ipv6_hdr(skb);
149 ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
150 if (skb->len < ip6hlen + len) {
151 /* packet is too small!?! */
155 /* pull the data buffer up to the ESP header and set the
156 * transport header to point to ESP. Keep UDP on the stack
159 __skb_pull(skb, len);
160 skb_reset_transport_header(skb);
163 return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0, encap_type);
170 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
172 return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
175 EXPORT_SYMBOL(xfrm6_rcv_tnl);
177 int xfrm6_rcv(struct sk_buff *skb)
179 return xfrm6_rcv_tnl(skb, NULL);
181 EXPORT_SYMBOL(xfrm6_rcv);
182 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
183 xfrm_address_t *saddr, u8 proto)
185 struct net *net = dev_net(skb->dev);
186 struct xfrm_state *x = NULL;
190 sp = secpath_set(skb);
192 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
196 if (1 + sp->len == XFRM_MAX_DEPTH) {
197 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
201 for (i = 0; i < 3; i++) {
202 xfrm_address_t *dst, *src;
210 /* lookup state with wild-card source address */
212 src = (xfrm_address_t *)&in6addr_any;
215 /* lookup state with wild-card addresses */
216 dst = (xfrm_address_t *)&in6addr_any;
217 src = (xfrm_address_t *)&in6addr_any;
221 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
227 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
228 likely(x->km.state == XFRM_STATE_VALID) &&
229 !xfrm_state_check_expire(x)) {
230 spin_unlock(&x->lock);
231 if (x->type->input(x, skb) > 0) {
232 /* found a valid state */
236 spin_unlock(&x->lock);
243 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
244 xfrm_audit_state_notfound_simple(skb, AF_INET6);
248 sp->xvec[sp->len++] = x;
252 x->curlft.bytes += skb->len;
255 spin_unlock(&x->lock);
262 EXPORT_SYMBOL(xfrm6_input_addr);