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>
26 #include <linux/net.h>
27 #include <linux/rculist.h>
28 #include <linux/udp.h>
32 #include <net/route.h>
40 * LISP encapsulation header:
42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43 * |N|L|E|V|I|flags| Nonce/Map-Version |
44 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45 * | Instance ID/Locator Status Bits |
46 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
51 * struct lisphdr - LISP header
52 * @nonce_present: Flag indicating the presence of a 24 bit nonce value.
53 * @locator_status_bits_present: Flag indicating the presence of Locator Status
55 * @solicit_echo_nonce: Flag indicating the use of the echo noncing mechanism.
56 * @map_version_present: Flag indicating the use of mapping versioning.
57 * @instance_id_present: Flag indicating the presence of a 24 bit Instance ID.
58 * @reserved_flags: 3 bits reserved for future flags.
59 * @nonce: 24 bit nonce value.
60 * @map_version: 24 bit mapping version.
61 * @locator_status_bits: Locator Status Bits: 32 bits when instance_id_present
62 * is not set, 8 bits when it is.
63 * @instance_id: 24 bit Instance ID
66 #ifdef __LITTLE_ENDIAN_BITFIELD
67 __u8 reserved_flags:3;
68 __u8 instance_id_present:1;
69 __u8 map_version_present:1;
70 __u8 solicit_echo_nonce:1;
71 __u8 locator_status_bits_present:1;
75 __u8 locator_status_bits_present:1;
76 __u8 solicit_echo_nonce:1;
77 __u8 map_version_present:1;
78 __u8 instance_id_present:1;
79 __u8 reserved_flags:3;
86 __be32 locator_status_bits;
89 __u8 locator_status_bits;
94 #define LISP_HLEN (sizeof(struct udphdr) + sizeof(struct lisphdr))
97 * struct lisp_port - Keeps track of open UDP ports
98 * @dst_port: lisp UDP port no.
99 * @list: list element in @lisp_ports.
100 * @lisp_rcv_socket: The socket created for this port number.
105 struct list_head list;
106 struct socket *lisp_rcv_socket;
110 static LIST_HEAD(lisp_ports);
112 static inline struct lisp_port *lisp_vport(const struct vport *vport)
114 return vport_priv(vport);
117 static struct lisp_port *lisp_find_port(struct net *net, __be16 port)
119 struct lisp_port *lisp_port;
121 list_for_each_entry_rcu(lisp_port, &lisp_ports, list) {
122 if (lisp_port->dst_port == port &&
123 net_eq(sock_net(lisp_port->lisp_rcv_socket->sk), net))
130 static inline struct lisphdr *lisp_hdr(const struct sk_buff *skb)
132 return (struct lisphdr *)(udp_hdr(skb) + 1);
135 /* Convert 64 bit tunnel ID to 24 bit Instance ID. */
136 static void tunnel_id_to_instance_id(__be64 tun_id, __u8 *iid)
140 iid[0] = (__force __u8)(tun_id >> 16);
141 iid[1] = (__force __u8)(tun_id >> 8);
142 iid[2] = (__force __u8)tun_id;
144 iid[0] = (__force __u8)((__force u64)tun_id >> 40);
145 iid[1] = (__force __u8)((__force u64)tun_id >> 48);
146 iid[2] = (__force __u8)((__force u64)tun_id >> 56);
150 /* Convert 24 bit Instance ID to 64 bit tunnel ID. */
151 static __be64 instance_id_to_tunnel_id(__u8 *iid)
154 return (iid[0] << 16) | (iid[1] << 8) | iid[2];
156 return (__force __be64)(((__force u64)iid[0] << 40) |
157 ((__force u64)iid[1] << 48) |
158 ((__force u64)iid[2] << 56));
162 /* Compute source UDP port for outgoing packet.
163 * Currently we use the flow hash.
165 static u16 ovs_tnl_get_src_port(struct sk_buff *skb)
170 struct sw_flow_key *pkt_key = OVS_CB(skb)->pkt_key;
171 u32 hash = jhash2((const u32 *)pkt_key,
172 sizeof(*pkt_key) / sizeof(u32), 0);
174 inet_get_local_port_range(&low, &high);
175 range = (high - low) + 1;
176 return (((u64) hash * range) >> 32) + low;
179 static void lisp_build_header(const struct vport *vport,
183 struct lisp_port *lisp_port = lisp_vport(vport);
184 struct udphdr *udph = udp_hdr(skb);
185 struct lisphdr *lisph = (struct lisphdr *)(udph + 1);
186 const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key;
188 udph->dest = lisp_port->dst_port;
189 udph->source = htons(ovs_tnl_get_src_port(skb));
191 udph->len = htons(skb->len - skb_transport_offset(skb));
193 lisph->nonce_present = 0; /* We don't support echo nonce algorithm */
194 lisph->locator_status_bits_present = 1; /* Set LSB */
195 lisph->solicit_echo_nonce = 0; /* No echo noncing */
196 lisph->map_version_present = 0; /* No mapping versioning, nonce instead */
197 lisph->instance_id_present = 1; /* Store the tun_id as Instance ID */
198 lisph->reserved_flags = 0; /* Reserved flags, set to 0 */
200 lisph->u1.nonce[0] = 0;
201 lisph->u1.nonce[1] = 0;
202 lisph->u1.nonce[2] = 0;
204 tunnel_id_to_instance_id(tun_key->tun_id, &lisph->u2.word2.instance_id[0]);
205 lisph->u2.word2.locator_status_bits = 1;
209 * ovs_tnl_rcv - ingress point for generic tunnel code
211 * @vport: port this packet was received on
212 * @skb: received packet
213 * @tun_key: tunnel that carried packet
215 * Must be called with rcu_read_lock.
217 * Packets received by this function are in the following state:
218 * - skb->data points to the inner Ethernet header.
219 * - The inner Ethernet header is in the linear data area.
220 * - The layer pointers are undefined.
222 static void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb,
223 struct ovs_key_ipv4_tunnel *tun_key)
227 skb_reset_mac_header(skb);
230 if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
231 skb->protocol = eh->h_proto;
233 skb->protocol = htons(ETH_P_802_2);
237 skb_clear_rxhash(skb);
239 vlan_set_tci(skb, 0);
241 ovs_vport_receive(vport, skb, tun_key);
244 /* Called with rcu_read_lock and BH disabled. */
245 static int lisp_rcv(struct sock *sk, struct sk_buff *skb)
247 struct lisp_port *lisp_port;
248 struct lisphdr *lisph;
249 struct iphdr *iph, *inner_iph;
250 struct ovs_key_ipv4_tunnel tun_key;
255 lisp_port = lisp_find_port(dev_net(skb->dev), udp_hdr(skb)->dest);
256 if (unlikely(!lisp_port))
259 if (unlikely(!pskb_may_pull(skb, LISP_HLEN)))
262 lisph = lisp_hdr(skb);
264 skb_pull_rcsum(skb, LISP_HLEN);
266 if (lisph->instance_id_present != 1)
269 key = instance_id_to_tunnel_id(&lisph->u2.word2.instance_id[0]);
271 /* Save outer tunnel values */
273 ovs_flow_tun_key_init(&tun_key, iph, key, TUNNEL_KEY);
275 /* Drop non-IP inner packets */
276 inner_iph = (struct iphdr *)(lisph + 1);
277 switch (inner_iph->version) {
279 protocol = htons(ETH_P_IP);
282 protocol = htons(ETH_P_IPV6);
288 /* Add Ethernet header */
289 ethh = (struct ethhdr *)skb_push(skb, ETH_HLEN);
290 memset(ethh, 0, ETH_HLEN);
291 ethh->h_dest[0] = 0x02;
292 ethh->h_source[0] = 0x02;
293 ethh->h_proto = protocol;
295 ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
297 ovs_tnl_rcv(vport_from_priv(lisp_port), skb, &tun_key);
306 /* Arbitrary value. Irrelevant as long as it's not 0 since we set the handler. */
307 #define UDP_ENCAP_LISP 1
308 static int lisp_socket_init(struct lisp_port *lisp_port, struct net *net)
310 struct sockaddr_in sin;
313 err = sock_create_kern(AF_INET, SOCK_DGRAM, 0,
314 &lisp_port->lisp_rcv_socket);
318 /* release net ref. */
319 sk_change_net(lisp_port->lisp_rcv_socket->sk, net);
321 sin.sin_family = AF_INET;
322 sin.sin_addr.s_addr = htonl(INADDR_ANY);
323 sin.sin_port = lisp_port->dst_port;
325 err = kernel_bind(lisp_port->lisp_rcv_socket, (struct sockaddr *)&sin,
326 sizeof(struct sockaddr_in));
330 udp_sk(lisp_port->lisp_rcv_socket->sk)->encap_type = UDP_ENCAP_LISP;
331 udp_sk(lisp_port->lisp_rcv_socket->sk)->encap_rcv = lisp_rcv;
338 sk_release_kernel(lisp_port->lisp_rcv_socket->sk);
340 pr_warn("cannot register lisp protocol handler: %d\n", err);
344 static int lisp_get_options(const struct vport *vport, struct sk_buff *skb)
346 struct lisp_port *lisp_port = lisp_vport(vport);
348 if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(lisp_port->dst_port)))
353 static void lisp_tnl_destroy(struct vport *vport)
355 struct lisp_port *lisp_port = lisp_vport(vport);
357 list_del_rcu(&lisp_port->list);
359 sk_release_kernel(lisp_port->lisp_rcv_socket->sk);
361 ovs_vport_deferred_free(vport);
364 static struct vport *lisp_tnl_create(const struct vport_parms *parms)
366 struct net *net = ovs_dp_get_net(parms->dp);
367 struct nlattr *options = parms->options;
368 struct lisp_port *lisp_port;
379 a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
380 if (a && nla_len(a) == sizeof(u16)) {
381 dst_port = nla_get_u16(a);
383 /* Require destination port from userspace. */
388 /* Verify if we already have a socket created for this port */
389 if (lisp_find_port(net, htons(dst_port))) {
394 vport = ovs_vport_alloc(sizeof(struct lisp_port),
395 &ovs_lisp_vport_ops, parms);
399 lisp_port = lisp_vport(vport);
400 lisp_port->dst_port = htons(dst_port);
401 strncpy(lisp_port->name, parms->name, IFNAMSIZ);
403 err = lisp_socket_init(lisp_port, net);
407 list_add_tail_rcu(&lisp_port->list, &lisp_ports);
411 ovs_vport_free(vport);
416 static bool need_linearize(const struct sk_buff *skb)
420 if (unlikely(skb_shinfo(skb)->frag_list))
424 * Generally speaking we should linearize if there are paged frags.
425 * However, if all of the refcounts are 1 we know nobody else can
426 * change them from underneath us and we can skip the linearization.
428 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
429 if (unlikely(page_count(skb_frag_page(&skb_shinfo(skb)->frags[i])) > 1))
435 static struct sk_buff *handle_offloads(struct sk_buff *skb)
439 if (skb_is_gso(skb)) {
440 struct sk_buff *nskb;
441 char cb[sizeof(skb->cb)];
443 memcpy(cb, skb->cb, sizeof(cb));
445 nskb = __skb_gso_segment(skb, 0, false);
454 memcpy(nskb->cb, cb, sizeof(cb));
457 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
458 /* Pages aren't locked and could change at any time.
459 * If this happens after we compute the checksum, the
460 * checksum will be wrong. We linearize now to avoid
463 if (unlikely(need_linearize(skb))) {
464 err = __skb_linearize(skb);
469 err = skb_checksum_help(skb);
474 skb->ip_summed = CHECKSUM_NONE;
481 static int ovs_tnl_send(struct vport *vport, struct sk_buff *skb,
482 u8 ipproto, int tunnel_hlen,
483 void (*build_header)(const struct vport *,
492 struct sk_buff *nskb;
495 saddr = OVS_CB(skb)->tun_key->ipv4_src;
496 rt = find_route(ovs_dp_get_net(vport->dp),
498 OVS_CB(skb)->tun_key->ipv4_dst,
500 OVS_CB(skb)->tun_key->ipv4_tos,
507 tunnel_hlen += sizeof(struct iphdr);
509 min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
511 + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
513 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
514 int head_delta = SKB_DATA_ALIGN(min_headroom -
518 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
525 nskb = handle_offloads(skb);
536 skb_clear_rxhash(skb);
539 struct sk_buff *next_skb = skb->next;
545 if (unlikely(vlan_deaccel_tag(skb)))
549 skb_push(skb, tunnel_hlen);
550 skb_reset_network_header(skb);
551 skb_set_transport_header(skb, sizeof(struct iphdr));
554 skb_dst_set(skb, dst_clone(&rt_dst(rt)));
556 skb_dst_set(skb, &rt_dst(rt));
558 /* Push Tunnel header. */
559 build_header(vport, skb, tunnel_hlen);
561 /* Push IP header. */
564 iph->ihl = sizeof(struct iphdr) >> 2;
565 iph->protocol = ipproto;
566 iph->daddr = OVS_CB(skb)->tun_key->ipv4_dst;
568 iph->tos = OVS_CB(skb)->tun_key->ipv4_tos;
569 iph->ttl = OVS_CB(skb)->tun_key->ipv4_ttl;
570 iph->frag_off = OVS_CB(skb)->tun_key->tun_flags &
571 TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
573 * Allow our local IP stack to fragment the outer packet even
574 * if the DF bit is set as a last resort. We also need to
575 * force selection of an IP ID here with __ip_select_ident(),
576 * as ip_select_ident() assumes a proper ID is not needed when
577 * when the DF bit is set.
580 __ip_select_ident(iph, skb_dst(skb), 0);
582 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
584 err = ip_local_out(skb);
585 if (unlikely(net_xmit_eval(err)))
588 sent_len += frag_len;
602 static int lisp_tnl_send(struct vport *vport, struct sk_buff *skb)
605 int network_offset = skb_network_offset(skb);
607 if (unlikely(!OVS_CB(skb)->tun_key))
610 /* We only encapsulate IPv4 and IPv6 packets */
611 switch (skb->protocol) {
612 case htons(ETH_P_IP):
613 case htons(ETH_P_IPV6):
614 /* Pop off "inner" Ethernet header */
615 skb_pull(skb, network_offset);
616 tnl_len = ovs_tnl_send(vport, skb, IPPROTO_UDP,
617 LISP_HLEN, lisp_build_header);
618 return tnl_len > 0 ? tnl_len + network_offset : tnl_len;
625 static const char *lisp_get_name(const struct vport *vport)
627 struct lisp_port *lisp_port = lisp_vport(vport);
628 return lisp_port->name;
631 const struct vport_ops ovs_lisp_vport_ops = {
632 .type = OVS_VPORT_TYPE_LISP,
633 .create = lisp_tnl_create,
634 .destroy = lisp_tnl_destroy,
635 .get_name = lisp_get_name,
636 .get_options = lisp_get_options,
637 .send = lisp_tnl_send,