2 * Copyright (c) 2007-2012 Nicira, Inc.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/skbuff.h>
24 #include <linux/openvswitch.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/in6.h>
28 #include <linux/if_arp.h>
29 #include <linux/if_vlan.h>
32 #include <net/checksum.h>
33 #include <net/dsfield.h>
40 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
41 const struct nlattr *attr, int len, bool keep_skb);
43 static int make_writable(struct sk_buff *skb, int write_len)
45 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
48 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
51 /* remove VLAN header from packet and update csum accordingly. */
52 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
54 struct vlan_hdr *vhdr;
57 err = make_writable(skb, VLAN_ETH_HLEN);
61 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
62 skb->csum = csum_sub(skb->csum, csum_partial(skb->data
63 + (2 * ETH_ALEN), VLAN_HLEN, 0));
65 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
66 *current_tci = vhdr->h_vlan_TCI;
68 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
69 __skb_pull(skb, VLAN_HLEN);
71 vlan_set_encap_proto(skb, vhdr);
72 skb->mac_header += VLAN_HLEN;
73 skb_reset_mac_len(skb);
78 static int pop_vlan(struct sk_buff *skb)
83 if (likely(vlan_tx_tag_present(skb))) {
86 if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
87 skb->len < VLAN_ETH_HLEN))
90 err = __pop_vlan_tci(skb, &tci);
94 /* move next vlan tag to hw accel tag */
95 if (likely(skb->protocol != htons(ETH_P_8021Q) ||
96 skb->len < VLAN_ETH_HLEN))
99 err = __pop_vlan_tci(skb, &tci);
103 __vlan_hwaccel_put_tag(skb, ntohs(tci));
107 static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
109 if (unlikely(vlan_tx_tag_present(skb))) {
112 /* push down current VLAN tag */
113 current_tag = vlan_tx_tag_get(skb);
115 if (!__vlan_put_tag(skb, current_tag))
118 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
119 skb->csum = csum_add(skb->csum, csum_partial(skb->data
120 + (2 * ETH_ALEN), VLAN_HLEN, 0));
123 __vlan_hwaccel_put_tag(skb, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
127 static int set_eth_addr(struct sk_buff *skb,
128 const struct ovs_key_ethernet *eth_key)
131 err = make_writable(skb, ETH_HLEN);
135 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
136 skb->csum = csum_sub(skb->csum, csum_partial(eth_hdr(skb),
139 memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
140 memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
142 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
143 skb->csum = csum_add(skb->csum, csum_partial(eth_hdr(skb),
149 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
150 __be32 *addr, __be32 new_addr)
152 int transport_len = skb->len - skb_transport_offset(skb);
154 if (nh->protocol == IPPROTO_TCP) {
155 if (likely(transport_len >= sizeof(struct tcphdr)))
156 inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
158 } else if (nh->protocol == IPPROTO_UDP) {
159 if (likely(transport_len >= sizeof(struct udphdr))) {
160 struct udphdr *uh = udp_hdr(skb);
163 get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
164 inet_proto_csum_replace4(&uh->check, skb,
167 uh->check = CSUM_MANGLED_0;
172 csum_replace4(&nh->check, *addr, new_addr);
173 skb_clear_rxhash(skb);
177 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
178 __be32 addr[4], const __be32 new_addr[4])
180 int transport_len = skb->len - skb_transport_offset(skb);
182 if (l4_proto == IPPROTO_TCP) {
183 if (likely(transport_len >= sizeof(struct tcphdr)))
184 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
186 } else if (l4_proto == IPPROTO_UDP) {
187 if (likely(transport_len >= sizeof(struct udphdr))) {
188 struct udphdr *uh = udp_hdr(skb);
191 get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
192 inet_proto_csum_replace16(&uh->check, skb,
195 uh->check = CSUM_MANGLED_0;
201 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
202 __be32 addr[4], const __be32 new_addr[4],
203 bool recalculate_csum)
205 if (recalculate_csum)
206 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
208 skb_clear_rxhash(skb);
209 memcpy(addr, new_addr, sizeof(__be32[4]));
212 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
214 nh->priority = tc >> 4;
215 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
218 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
220 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
221 nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
222 nh->flow_lbl[2] = fl & 0x000000FF;
225 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
227 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
231 static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
236 err = make_writable(skb, skb_network_offset(skb) +
237 sizeof(struct iphdr));
243 if (ipv4_key->ipv4_src != nh->saddr)
244 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
246 if (ipv4_key->ipv4_dst != nh->daddr)
247 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
249 if (ipv4_key->ipv4_tos != nh->tos)
250 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
252 if (ipv4_key->ipv4_ttl != nh->ttl)
253 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
258 static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
265 err = make_writable(skb, skb_network_offset(skb) +
266 sizeof(struct ipv6hdr));
271 saddr = (__be32 *)&nh->saddr;
272 daddr = (__be32 *)&nh->daddr;
274 if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
275 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
276 ipv6_key->ipv6_src, true);
278 if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
279 unsigned int offset = 0;
280 int flags = OVS_IP6T_FH_F_SKIP_RH;
281 bool recalc_csum = true;
283 if (ipv6_ext_hdr(nh->nexthdr))
284 recalc_csum = ipv6_find_hdr(skb, &offset,
285 NEXTHDR_ROUTING, NULL,
286 &flags) != NEXTHDR_ROUTING;
288 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
289 ipv6_key->ipv6_dst, recalc_csum);
292 set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
293 set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
294 nh->hop_limit = ipv6_key->ipv6_hlimit;
299 /* Must follow make_writable() since that can move the skb data. */
300 static void set_tp_port(struct sk_buff *skb, __be16 *port,
301 __be16 new_port, __sum16 *check)
303 inet_proto_csum_replace2(check, skb, *port, new_port, 0);
305 skb_clear_rxhash(skb);
308 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
310 struct udphdr *uh = udp_hdr(skb);
312 if (uh->check && get_ip_summed(skb) != OVS_CSUM_PARTIAL) {
313 set_tp_port(skb, port, new_port, &uh->check);
316 uh->check = CSUM_MANGLED_0;
319 skb_clear_rxhash(skb);
323 static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
328 err = make_writable(skb, skb_transport_offset(skb) +
329 sizeof(struct udphdr));
334 if (udp_port_key->udp_src != uh->source)
335 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
337 if (udp_port_key->udp_dst != uh->dest)
338 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
343 static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
348 err = make_writable(skb, skb_transport_offset(skb) +
349 sizeof(struct tcphdr));
354 if (tcp_port_key->tcp_src != th->source)
355 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
357 if (tcp_port_key->tcp_dst != th->dest)
358 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
363 static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
370 vport = ovs_vport_rcu(dp, out_port);
371 if (unlikely(!vport)) {
376 ovs_vport_send(vport, skb);
380 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
381 const struct nlattr *attr)
383 struct dp_upcall_info upcall;
384 const struct nlattr *a;
387 upcall.cmd = OVS_PACKET_CMD_ACTION;
388 upcall.key = &OVS_CB(skb)->flow->key;
389 upcall.userdata = NULL;
392 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
393 a = nla_next(a, &rem)) {
394 switch (nla_type(a)) {
395 case OVS_USERSPACE_ATTR_USERDATA:
399 case OVS_USERSPACE_ATTR_PID:
400 upcall.portid = nla_get_u32(a);
405 return ovs_dp_upcall(dp, skb, &upcall);
408 static int sample(struct datapath *dp, struct sk_buff *skb,
409 const struct nlattr *attr)
411 const struct nlattr *acts_list = NULL;
412 const struct nlattr *a;
415 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
416 a = nla_next(a, &rem)) {
417 switch (nla_type(a)) {
418 case OVS_SAMPLE_ATTR_PROBABILITY:
419 if (net_random() >= nla_get_u32(a))
423 case OVS_SAMPLE_ATTR_ACTIONS:
429 return do_execute_actions(dp, skb, nla_data(acts_list),
430 nla_len(acts_list), true);
433 static int execute_set_action(struct sk_buff *skb,
434 const struct nlattr *nested_attr)
438 switch (nla_type(nested_attr)) {
439 case OVS_KEY_ATTR_PRIORITY:
440 skb->priority = nla_get_u32(nested_attr);
443 case OVS_KEY_ATTR_SKB_MARK:
444 skb_set_mark(skb, nla_get_u32(nested_attr));
447 case OVS_KEY_ATTR_IPV4_TUNNEL:
448 OVS_CB(skb)->tun_key = nla_data(nested_attr);
451 case OVS_KEY_ATTR_ETHERNET:
452 err = set_eth_addr(skb, nla_data(nested_attr));
455 case OVS_KEY_ATTR_IPV4:
456 err = set_ipv4(skb, nla_data(nested_attr));
459 case OVS_KEY_ATTR_IPV6:
460 err = set_ipv6(skb, nla_data(nested_attr));
463 case OVS_KEY_ATTR_TCP:
464 err = set_tcp(skb, nla_data(nested_attr));
467 case OVS_KEY_ATTR_UDP:
468 err = set_udp(skb, nla_data(nested_attr));
475 /* Execute a list of actions against 'skb'. */
476 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
477 const struct nlattr *attr, int len, bool keep_skb)
479 /* Every output action needs a separate clone of 'skb', but the common
480 * case is just a single output action, so that doing a clone and
481 * then freeing the original skbuff is wasteful. So the following code
482 * is slightly obscure just to avoid that. */
484 const struct nlattr *a;
487 for (a = attr, rem = len; rem > 0;
488 a = nla_next(a, &rem)) {
491 if (prev_port != -1) {
492 do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
496 switch (nla_type(a)) {
497 case OVS_ACTION_ATTR_OUTPUT:
498 prev_port = nla_get_u32(a);
501 case OVS_ACTION_ATTR_USERSPACE:
502 output_userspace(dp, skb, a);
505 case OVS_ACTION_ATTR_PUSH_VLAN:
506 err = push_vlan(skb, nla_data(a));
507 if (unlikely(err)) /* skb already freed. */
511 case OVS_ACTION_ATTR_POP_VLAN:
515 case OVS_ACTION_ATTR_SET:
516 err = execute_set_action(skb, nla_data(a));
519 case OVS_ACTION_ATTR_SAMPLE:
520 err = sample(dp, skb, a);
530 if (prev_port != -1) {
532 skb = skb_clone(skb, GFP_ATOMIC);
534 do_output(dp, skb, prev_port);
535 } else if (!keep_skb)
541 /* We limit the number of times that we pass into execute_actions()
542 * to avoid blowing out the stack in the event that we have a loop. */
545 struct loop_counter {
546 u8 count; /* Count. */
547 bool looping; /* Loop detected? */
550 static DEFINE_PER_CPU(struct loop_counter, loop_counters);
552 static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions)
555 pr_warn("%s: flow looped %d times, dropping\n",
556 ovs_dp_name(dp), MAX_LOOPS);
557 actions->actions_len = 0;
561 /* Execute a list of actions against 'skb'. */
562 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
564 struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
565 struct loop_counter *loop;
568 /* Check whether we've looped too much. */
569 loop = &__get_cpu_var(loop_counters);
570 if (unlikely(++loop->count > MAX_LOOPS))
571 loop->looping = true;
572 if (unlikely(loop->looping)) {
573 error = loop_suppress(dp, acts);
578 OVS_CB(skb)->tun_key = NULL;
579 error = do_execute_actions(dp, skb, acts->actions,
580 acts->actions_len, false);
582 /* Check whether sub-actions looped too much. */
583 if (unlikely(loop->looping))
584 error = loop_suppress(dp, acts);
587 /* Decrement loop counter. */
589 loop->looping = false;