2 * Copyright (c) 2011 Nicira, Inc.
3 * Copyright (c) 2013 Cisco Systems, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 #include <linux/version.h>
23 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
27 #include <linux/net.h>
28 #include <linux/rculist.h>
29 #include <linux/udp.h>
33 #include <net/route.h>
41 * LISP encapsulation header:
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * |N|L|E|V|I|flags| Nonce/Map-Version |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 * | Instance ID/Locator Status Bits |
47 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
52 * struct lisphdr - LISP header
53 * @nonce_present: Flag indicating the presence of a 24 bit nonce value.
54 * @locator_status_bits_present: Flag indicating the presence of Locator Status
56 * @solicit_echo_nonce: Flag indicating the use of the echo noncing mechanism.
57 * @map_version_present: Flag indicating the use of mapping versioning.
58 * @instance_id_present: Flag indicating the presence of a 24 bit Instance ID.
59 * @reserved_flags: 3 bits reserved for future flags.
60 * @nonce: 24 bit nonce value.
61 * @map_version: 24 bit mapping version.
62 * @locator_status_bits: Locator Status Bits: 32 bits when instance_id_present
63 * is not set, 8 bits when it is.
64 * @instance_id: 24 bit Instance ID
67 #ifdef __LITTLE_ENDIAN_BITFIELD
68 __u8 reserved_flags:3;
69 __u8 instance_id_present:1;
70 __u8 map_version_present:1;
71 __u8 solicit_echo_nonce:1;
72 __u8 locator_status_bits_present:1;
76 __u8 locator_status_bits_present:1;
77 __u8 solicit_echo_nonce:1;
78 __u8 map_version_present:1;
79 __u8 instance_id_present:1;
80 __u8 reserved_flags:3;
87 __be32 locator_status_bits;
90 __u8 locator_status_bits;
95 #define LISP_HLEN (sizeof(struct udphdr) + sizeof(struct lisphdr))
98 * struct lisp_port - Keeps track of open UDP ports
99 * @dst_port: lisp UDP port no.
100 * @list: list element in @lisp_ports.
101 * @lisp_rcv_socket: The socket created for this port number.
106 struct list_head list;
107 struct socket *lisp_rcv_socket;
111 static LIST_HEAD(lisp_ports);
113 static inline struct lisp_port *lisp_vport(const struct vport *vport)
115 return vport_priv(vport);
118 static struct lisp_port *lisp_find_port(struct net *net, __be16 port)
120 struct lisp_port *lisp_port;
122 list_for_each_entry_rcu(lisp_port, &lisp_ports, list) {
123 if (lisp_port->dst_port == port &&
124 net_eq(sock_net(lisp_port->lisp_rcv_socket->sk), net))
131 static inline struct lisphdr *lisp_hdr(const struct sk_buff *skb)
133 return (struct lisphdr *)(udp_hdr(skb) + 1);
136 /* Convert 64 bit tunnel ID to 24 bit Instance ID. */
137 static void tunnel_id_to_instance_id(__be64 tun_id, __u8 *iid)
141 iid[0] = (__force __u8)(tun_id >> 16);
142 iid[1] = (__force __u8)(tun_id >> 8);
143 iid[2] = (__force __u8)tun_id;
145 iid[0] = (__force __u8)((__force u64)tun_id >> 40);
146 iid[1] = (__force __u8)((__force u64)tun_id >> 48);
147 iid[2] = (__force __u8)((__force u64)tun_id >> 56);
151 /* Convert 24 bit Instance ID to 64 bit tunnel ID. */
152 static __be64 instance_id_to_tunnel_id(__u8 *iid)
155 return (iid[0] << 16) | (iid[1] << 8) | iid[2];
157 return (__force __be64)(((__force u64)iid[0] << 40) |
158 ((__force u64)iid[1] << 48) |
159 ((__force u64)iid[2] << 56));
163 /* Compute source UDP port for outgoing packet.
164 * Currently we use the flow hash.
166 static u16 ovs_tnl_get_src_port(struct sk_buff *skb)
171 struct sw_flow_key *pkt_key = OVS_CB(skb)->pkt_key;
172 u32 hash = jhash2((const u32 *)pkt_key,
173 sizeof(*pkt_key) / sizeof(u32), 0);
175 inet_get_local_port_range(&low, &high);
176 range = (high - low) + 1;
177 return (((u64) hash * range) >> 32) + low;
180 static void lisp_build_header(const struct vport *vport,
184 struct lisp_port *lisp_port = lisp_vport(vport);
185 struct udphdr *udph = udp_hdr(skb);
186 struct lisphdr *lisph = (struct lisphdr *)(udph + 1);
187 const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key;
189 udph->dest = lisp_port->dst_port;
190 udph->source = htons(ovs_tnl_get_src_port(skb));
192 udph->len = htons(skb->len - skb_transport_offset(skb));
194 lisph->nonce_present = 0; /* We don't support echo nonce algorithm */
195 lisph->locator_status_bits_present = 1; /* Set LSB */
196 lisph->solicit_echo_nonce = 0; /* No echo noncing */
197 lisph->map_version_present = 0; /* No mapping versioning, nonce instead */
198 lisph->instance_id_present = 1; /* Store the tun_id as Instance ID */
199 lisph->reserved_flags = 0; /* Reserved flags, set to 0 */
201 lisph->u1.nonce[0] = 0;
202 lisph->u1.nonce[1] = 0;
203 lisph->u1.nonce[2] = 0;
205 tunnel_id_to_instance_id(tun_key->tun_id, &lisph->u2.word2.instance_id[0]);
206 lisph->u2.word2.locator_status_bits = 1;
210 * ovs_tnl_rcv - ingress point for generic tunnel code
212 * @vport: port this packet was received on
213 * @skb: received packet
214 * @tun_key: tunnel that carried packet
216 * Must be called with rcu_read_lock.
218 * Packets received by this function are in the following state:
219 * - skb->data points to the inner Ethernet header.
220 * - The inner Ethernet header is in the linear data area.
221 * - The layer pointers are undefined.
223 static void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb,
224 struct ovs_key_ipv4_tunnel *tun_key)
228 skb_reset_mac_header(skb);
231 if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
232 skb->protocol = eh->h_proto;
234 skb->protocol = htons(ETH_P_802_2);
238 skb_clear_rxhash(skb);
240 vlan_set_tci(skb, 0);
242 if (unlikely(compute_ip_summed(skb, false))) {
247 ovs_vport_receive(vport, skb, tun_key);
250 /* Called with rcu_read_lock and BH disabled. */
251 static int lisp_rcv(struct sock *sk, struct sk_buff *skb)
253 struct lisp_port *lisp_port;
254 struct lisphdr *lisph;
255 struct iphdr *iph, *inner_iph;
256 struct ovs_key_ipv4_tunnel tun_key;
261 lisp_port = lisp_find_port(dev_net(skb->dev), udp_hdr(skb)->dest);
262 if (unlikely(!lisp_port))
265 if (unlikely(!pskb_may_pull(skb, LISP_HLEN)))
268 lisph = lisp_hdr(skb);
270 skb_pull_rcsum(skb, LISP_HLEN);
272 if (lisph->instance_id_present != 1)
275 key = instance_id_to_tunnel_id(&lisph->u2.word2.instance_id[0]);
277 /* Save outer tunnel values */
279 ovs_flow_tun_key_init(&tun_key, iph, key, TUNNEL_KEY);
281 /* Drop non-IP inner packets */
282 inner_iph = (struct iphdr *)(lisph + 1);
283 switch (inner_iph->version) {
285 protocol = htons(ETH_P_IP);
288 protocol = htons(ETH_P_IPV6);
294 /* Add Ethernet header */
295 ethh = (struct ethhdr *)skb_push(skb, ETH_HLEN);
296 memset(ethh, 0, ETH_HLEN);
297 ethh->h_dest[0] = 0x02;
298 ethh->h_source[0] = 0x02;
299 ethh->h_proto = protocol;
301 ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
303 ovs_tnl_rcv(vport_from_priv(lisp_port), skb, &tun_key);
312 /* Arbitrary value. Irrelevant as long as it's not 0 since we set the handler. */
313 #define UDP_ENCAP_LISP 1
314 static int lisp_socket_init(struct lisp_port *lisp_port, struct net *net)
316 struct sockaddr_in sin;
319 err = sock_create_kern(AF_INET, SOCK_DGRAM, 0,
320 &lisp_port->lisp_rcv_socket);
324 /* release net ref. */
325 sk_change_net(lisp_port->lisp_rcv_socket->sk, net);
327 sin.sin_family = AF_INET;
328 sin.sin_addr.s_addr = htonl(INADDR_ANY);
329 sin.sin_port = lisp_port->dst_port;
331 err = kernel_bind(lisp_port->lisp_rcv_socket, (struct sockaddr *)&sin,
332 sizeof(struct sockaddr_in));
336 udp_sk(lisp_port->lisp_rcv_socket->sk)->encap_type = UDP_ENCAP_LISP;
337 udp_sk(lisp_port->lisp_rcv_socket->sk)->encap_rcv = lisp_rcv;
344 sk_release_kernel(lisp_port->lisp_rcv_socket->sk);
346 pr_warn("cannot register lisp protocol handler: %d\n", err);
350 static int lisp_get_options(const struct vport *vport, struct sk_buff *skb)
352 struct lisp_port *lisp_port = lisp_vport(vport);
354 if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(lisp_port->dst_port)))
359 static void lisp_tnl_destroy(struct vport *vport)
361 struct lisp_port *lisp_port = lisp_vport(vport);
363 list_del_rcu(&lisp_port->list);
365 sk_release_kernel(lisp_port->lisp_rcv_socket->sk);
367 ovs_vport_deferred_free(vport);
370 static struct vport *lisp_tnl_create(const struct vport_parms *parms)
372 struct net *net = ovs_dp_get_net(parms->dp);
373 struct nlattr *options = parms->options;
374 struct lisp_port *lisp_port;
385 a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
386 if (a && nla_len(a) == sizeof(u16)) {
387 dst_port = nla_get_u16(a);
389 /* Require destination port from userspace. */
394 /* Verify if we already have a socket created for this port */
395 if (lisp_find_port(net, htons(dst_port))) {
400 vport = ovs_vport_alloc(sizeof(struct lisp_port),
401 &ovs_lisp_vport_ops, parms);
405 lisp_port = lisp_vport(vport);
406 lisp_port->dst_port = htons(dst_port);
407 strncpy(lisp_port->name, parms->name, IFNAMSIZ);
409 err = lisp_socket_init(lisp_port, net);
413 list_add_tail_rcu(&lisp_port->list, &lisp_ports);
417 ovs_vport_free(vport);
422 static bool need_linearize(const struct sk_buff *skb)
426 if (unlikely(skb_shinfo(skb)->frag_list))
430 * Generally speaking we should linearize if there are paged frags.
431 * However, if all of the refcounts are 1 we know nobody else can
432 * change them from underneath us and we can skip the linearization.
434 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
435 if (unlikely(page_count(skb_frag_page(&skb_shinfo(skb)->frags[i])) > 1))
441 static struct sk_buff *handle_offloads(struct sk_buff *skb)
445 forward_ip_summed(skb, true);
448 if (skb_is_gso(skb)) {
449 struct sk_buff *nskb;
450 char cb[sizeof(skb->cb)];
452 memcpy(cb, skb->cb, sizeof(cb));
454 nskb = __skb_gso_segment(skb, 0, false);
463 memcpy(nskb->cb, cb, sizeof(cb));
466 } else if (get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
467 /* Pages aren't locked and could change at any time.
468 * If this happens after we compute the checksum, the
469 * checksum will be wrong. We linearize now to avoid
472 if (unlikely(need_linearize(skb))) {
473 err = __skb_linearize(skb);
478 err = skb_checksum_help(skb);
483 set_ip_summed(skb, OVS_CSUM_NONE);
491 static int ovs_tnl_send(struct vport *vport, struct sk_buff *skb,
492 u8 ipproto, int tunnel_hlen,
493 void (*build_header)(const struct vport *,
502 struct sk_buff *nskb;
505 saddr = OVS_CB(skb)->tun_key->ipv4_src;
506 rt = find_route(ovs_dp_get_net(vport->dp),
508 OVS_CB(skb)->tun_key->ipv4_dst,
510 OVS_CB(skb)->tun_key->ipv4_tos,
517 tunnel_hlen += sizeof(struct iphdr);
519 min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
521 + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
523 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
524 int head_delta = SKB_DATA_ALIGN(min_headroom -
528 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
535 nskb = handle_offloads(skb);
546 skb_clear_rxhash(skb);
549 struct sk_buff *next_skb = skb->next;
555 if (unlikely(vlan_deaccel_tag(skb)))
559 skb_push(skb, tunnel_hlen);
560 skb_reset_network_header(skb);
561 skb_set_transport_header(skb, sizeof(struct iphdr));
564 skb_dst_set(skb, dst_clone(&rt_dst(rt)));
566 skb_dst_set(skb, &rt_dst(rt));
568 /* Push Tunnel header. */
569 build_header(vport, skb, tunnel_hlen);
571 /* Push IP header. */
574 iph->ihl = sizeof(struct iphdr) >> 2;
575 iph->protocol = ipproto;
576 iph->daddr = OVS_CB(skb)->tun_key->ipv4_dst;
578 iph->tos = OVS_CB(skb)->tun_key->ipv4_tos;
579 iph->ttl = OVS_CB(skb)->tun_key->ipv4_ttl;
580 iph->frag_off = OVS_CB(skb)->tun_key->tun_flags &
581 TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
583 * Allow our local IP stack to fragment the outer packet even
584 * if the DF bit is set as a last resort. We also need to
585 * force selection of an IP ID here with __ip_select_ident(),
586 * as ip_select_ident() assumes a proper ID is not needed when
587 * when the DF bit is set.
590 __ip_select_ident(iph, skb_dst(skb), 0);
592 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
594 err = ip_local_out(skb);
595 if (unlikely(net_xmit_eval(err)))
598 sent_len += frag_len;
612 static int lisp_tnl_send(struct vport *vport, struct sk_buff *skb)
615 int network_offset = skb_network_offset(skb);
617 if (unlikely(!OVS_CB(skb)->tun_key))
620 /* We only encapsulate IPv4 and IPv6 packets */
621 switch (skb->protocol) {
622 case htons(ETH_P_IP):
623 case htons(ETH_P_IPV6):
624 /* Pop off "inner" Ethernet header */
625 skb_pull(skb, network_offset);
626 tnl_len = ovs_tnl_send(vport, skb, IPPROTO_UDP,
627 LISP_HLEN, lisp_build_header);
628 return tnl_len > 0 ? tnl_len + network_offset : tnl_len;
635 static const char *lisp_get_name(const struct vport *vport)
637 struct lisp_port *lisp_port = lisp_vport(vport);
638 return lisp_port->name;
641 const struct vport_ops ovs_lisp_vport_ops = {
642 .type = OVS_VPORT_TYPE_LISP,
643 .create = lisp_tnl_create,
644 .destroy = lisp_tnl_destroy,
645 .get_name = lisp_get_name,
646 .get_options = lisp_get_options,
647 .send = lisp_tnl_send,
650 #warning LISP tunneling will not be available on kernels before 2.6.26
651 #endif /* Linux kernel < 2.6.26 */