2 * Copyright (c) 2007-2013 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/sctp.h>
26 #include <linux/tcp.h>
27 #include <linux/udp.h>
28 #include <linux/in6.h>
29 #include <linux/if_arp.h>
30 #include <linux/if_vlan.h>
33 #include <net/checksum.h>
34 #include <net/dsfield.h>
35 #include <net/sctp/checksum.h>
42 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
43 const struct nlattr *attr, int len, bool keep_skb);
45 static int make_writable(struct sk_buff *skb, int write_len)
47 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
50 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
53 /* remove VLAN header from packet and update csum accordingly. */
54 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
56 struct vlan_hdr *vhdr;
59 err = make_writable(skb, VLAN_ETH_HLEN);
63 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
64 skb->csum = csum_sub(skb->csum, csum_partial(skb->data
65 + (2 * ETH_ALEN), VLAN_HLEN, 0));
67 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
68 *current_tci = vhdr->h_vlan_TCI;
70 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
71 __skb_pull(skb, VLAN_HLEN);
73 vlan_set_encap_proto(skb, vhdr);
74 skb->mac_header += VLAN_HLEN;
75 skb_reset_mac_len(skb);
80 static int pop_vlan(struct sk_buff *skb)
85 if (likely(vlan_tx_tag_present(skb))) {
88 if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
89 skb->len < VLAN_ETH_HLEN))
92 err = __pop_vlan_tci(skb, &tci);
96 /* move next vlan tag to hw accel tag */
97 if (likely(skb->protocol != htons(ETH_P_8021Q) ||
98 skb->len < VLAN_ETH_HLEN))
101 err = __pop_vlan_tci(skb, &tci);
105 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
109 static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
111 if (unlikely(vlan_tx_tag_present(skb))) {
114 /* push down current VLAN tag */
115 current_tag = vlan_tx_tag_get(skb);
117 if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
120 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
121 skb->csum = csum_add(skb->csum, csum_partial(skb->data
122 + (2 * ETH_ALEN), VLAN_HLEN, 0));
125 __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
129 static int set_eth_addr(struct sk_buff *skb,
130 const struct ovs_key_ethernet *eth_key)
133 err = make_writable(skb, ETH_HLEN);
137 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
138 skb->csum = csum_sub(skb->csum, csum_partial(eth_hdr(skb),
141 memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
142 memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
144 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
145 skb->csum = csum_add(skb->csum, csum_partial(eth_hdr(skb),
151 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
152 __be32 *addr, __be32 new_addr)
154 int transport_len = skb->len - skb_transport_offset(skb);
156 if (nh->protocol == IPPROTO_TCP) {
157 if (likely(transport_len >= sizeof(struct tcphdr)))
158 inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
160 } else if (nh->protocol == IPPROTO_UDP) {
161 if (likely(transport_len >= sizeof(struct udphdr))) {
162 struct udphdr *uh = udp_hdr(skb);
165 get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
166 inet_proto_csum_replace4(&uh->check, skb,
169 uh->check = CSUM_MANGLED_0;
174 csum_replace4(&nh->check, *addr, new_addr);
175 skb_clear_rxhash(skb);
179 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
180 __be32 addr[4], const __be32 new_addr[4])
182 int transport_len = skb->len - skb_transport_offset(skb);
184 if (l4_proto == IPPROTO_TCP) {
185 if (likely(transport_len >= sizeof(struct tcphdr)))
186 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
188 } else if (l4_proto == IPPROTO_UDP) {
189 if (likely(transport_len >= sizeof(struct udphdr))) {
190 struct udphdr *uh = udp_hdr(skb);
193 get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
194 inet_proto_csum_replace16(&uh->check, skb,
197 uh->check = CSUM_MANGLED_0;
203 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
204 __be32 addr[4], const __be32 new_addr[4],
205 bool recalculate_csum)
207 if (recalculate_csum)
208 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
210 skb_clear_rxhash(skb);
211 memcpy(addr, new_addr, sizeof(__be32[4]));
214 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
216 nh->priority = tc >> 4;
217 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
220 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
222 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
223 nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
224 nh->flow_lbl[2] = fl & 0x000000FF;
227 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
229 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
233 static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
238 err = make_writable(skb, skb_network_offset(skb) +
239 sizeof(struct iphdr));
245 if (ipv4_key->ipv4_src != nh->saddr)
246 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
248 if (ipv4_key->ipv4_dst != nh->daddr)
249 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
251 if (ipv4_key->ipv4_tos != nh->tos)
252 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
254 if (ipv4_key->ipv4_ttl != nh->ttl)
255 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
260 static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
267 err = make_writable(skb, skb_network_offset(skb) +
268 sizeof(struct ipv6hdr));
273 saddr = (__be32 *)&nh->saddr;
274 daddr = (__be32 *)&nh->daddr;
276 if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
277 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
278 ipv6_key->ipv6_src, true);
280 if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
281 unsigned int offset = 0;
282 int flags = OVS_IP6T_FH_F_SKIP_RH;
283 bool recalc_csum = true;
285 if (ipv6_ext_hdr(nh->nexthdr))
286 recalc_csum = ipv6_find_hdr(skb, &offset,
287 NEXTHDR_ROUTING, NULL,
288 &flags) != NEXTHDR_ROUTING;
290 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
291 ipv6_key->ipv6_dst, recalc_csum);
294 set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
295 set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
296 nh->hop_limit = ipv6_key->ipv6_hlimit;
301 /* Must follow make_writable() since that can move the skb data. */
302 static void set_tp_port(struct sk_buff *skb, __be16 *port,
303 __be16 new_port, __sum16 *check)
305 inet_proto_csum_replace2(check, skb, *port, new_port, 0);
307 skb_clear_rxhash(skb);
310 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
312 struct udphdr *uh = udp_hdr(skb);
314 if (uh->check && get_ip_summed(skb) != OVS_CSUM_PARTIAL) {
315 set_tp_port(skb, port, new_port, &uh->check);
318 uh->check = CSUM_MANGLED_0;
321 skb_clear_rxhash(skb);
325 static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
330 err = make_writable(skb, skb_transport_offset(skb) +
331 sizeof(struct udphdr));
336 if (udp_port_key->udp_src != uh->source)
337 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
339 if (udp_port_key->udp_dst != uh->dest)
340 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
345 static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
350 err = make_writable(skb, skb_transport_offset(skb) +
351 sizeof(struct tcphdr));
356 if (tcp_port_key->tcp_src != th->source)
357 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
359 if (tcp_port_key->tcp_dst != th->dest)
360 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
365 static int set_sctp(struct sk_buff *skb,
366 const struct ovs_key_sctp *sctp_port_key)
370 unsigned int sctphoff = skb_transport_offset(skb);
372 err = make_writable(skb, sctphoff + sizeof(struct sctphdr));
377 if (sctp_port_key->sctp_src != sh->source ||
378 sctp_port_key->sctp_dst != sh->dest) {
379 __le32 old_correct_csum, new_csum, old_csum;
381 old_csum = sh->checksum;
382 old_correct_csum = sctp_compute_cksum(skb, sctphoff);
384 sh->source = sctp_port_key->sctp_src;
385 sh->dest = sctp_port_key->sctp_dst;
387 new_csum = sctp_compute_cksum(skb, sctphoff);
389 /* Carry any checksum errors through. */
390 sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
392 skb_clear_rxhash(skb);
398 static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
405 vport = ovs_vport_rcu(dp, out_port);
406 if (unlikely(!vport)) {
411 ovs_vport_send(vport, skb);
415 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
416 const struct nlattr *attr)
418 struct dp_upcall_info upcall;
419 const struct nlattr *a;
422 BUG_ON(!OVS_CB(skb)->pkt_key);
424 upcall.cmd = OVS_PACKET_CMD_ACTION;
425 upcall.key = OVS_CB(skb)->pkt_key;
426 upcall.userdata = NULL;
429 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
430 a = nla_next(a, &rem)) {
431 switch (nla_type(a)) {
432 case OVS_USERSPACE_ATTR_USERDATA:
436 case OVS_USERSPACE_ATTR_PID:
437 upcall.portid = nla_get_u32(a);
442 return ovs_dp_upcall(dp, skb, &upcall);
445 static int sample(struct datapath *dp, struct sk_buff *skb,
446 const struct nlattr *attr)
448 const struct nlattr *acts_list = NULL;
449 const struct nlattr *a;
452 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
453 a = nla_next(a, &rem)) {
454 switch (nla_type(a)) {
455 case OVS_SAMPLE_ATTR_PROBABILITY:
456 if (net_random() >= nla_get_u32(a))
460 case OVS_SAMPLE_ATTR_ACTIONS:
466 return do_execute_actions(dp, skb, nla_data(acts_list),
467 nla_len(acts_list), true);
470 static int execute_set_action(struct sk_buff *skb,
471 const struct nlattr *nested_attr)
475 switch (nla_type(nested_attr)) {
476 case OVS_KEY_ATTR_PRIORITY:
477 skb->priority = nla_get_u32(nested_attr);
480 case OVS_KEY_ATTR_SKB_MARK:
481 skb_set_mark(skb, nla_get_u32(nested_attr));
484 case OVS_KEY_ATTR_IPV4_TUNNEL:
485 OVS_CB(skb)->tun_key = nla_data(nested_attr);
488 case OVS_KEY_ATTR_ETHERNET:
489 err = set_eth_addr(skb, nla_data(nested_attr));
492 case OVS_KEY_ATTR_IPV4:
493 err = set_ipv4(skb, nla_data(nested_attr));
496 case OVS_KEY_ATTR_IPV6:
497 err = set_ipv6(skb, nla_data(nested_attr));
500 case OVS_KEY_ATTR_TCP:
501 err = set_tcp(skb, nla_data(nested_attr));
504 case OVS_KEY_ATTR_UDP:
505 err = set_udp(skb, nla_data(nested_attr));
508 case OVS_KEY_ATTR_SCTP:
509 err = set_sctp(skb, nla_data(nested_attr));
516 /* Execute a list of actions against 'skb'. */
517 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
518 const struct nlattr *attr, int len, bool keep_skb)
520 /* Every output action needs a separate clone of 'skb', but the common
521 * case is just a single output action, so that doing a clone and
522 * then freeing the original skbuff is wasteful. So the following code
523 * is slightly obscure just to avoid that. */
525 const struct nlattr *a;
528 for (a = attr, rem = len; rem > 0;
529 a = nla_next(a, &rem)) {
532 if (prev_port != -1) {
533 do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
537 switch (nla_type(a)) {
538 case OVS_ACTION_ATTR_OUTPUT:
539 prev_port = nla_get_u32(a);
542 case OVS_ACTION_ATTR_USERSPACE:
543 output_userspace(dp, skb, a);
546 case OVS_ACTION_ATTR_PUSH_VLAN:
547 err = push_vlan(skb, nla_data(a));
548 if (unlikely(err)) /* skb already freed. */
552 case OVS_ACTION_ATTR_POP_VLAN:
556 case OVS_ACTION_ATTR_SET:
557 err = execute_set_action(skb, nla_data(a));
560 case OVS_ACTION_ATTR_SAMPLE:
561 err = sample(dp, skb, a);
571 if (prev_port != -1) {
573 skb = skb_clone(skb, GFP_ATOMIC);
575 do_output(dp, skb, prev_port);
576 } else if (!keep_skb)
582 /* We limit the number of times that we pass into execute_actions()
583 * to avoid blowing out the stack in the event that we have a loop. */
586 struct loop_counter {
587 u8 count; /* Count. */
588 bool looping; /* Loop detected? */
591 static DEFINE_PER_CPU(struct loop_counter, loop_counters);
593 static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions)
596 pr_warn("%s: flow looped %d times, dropping\n",
597 ovs_dp_name(dp), MAX_LOOPS);
598 actions->actions_len = 0;
602 /* Execute a list of actions against 'skb'. */
603 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
605 struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
606 struct loop_counter *loop;
609 /* Check whether we've looped too much. */
610 loop = &__get_cpu_var(loop_counters);
611 if (unlikely(++loop->count > MAX_LOOPS))
612 loop->looping = true;
613 if (unlikely(loop->looping)) {
614 error = loop_suppress(dp, acts);
619 OVS_CB(skb)->tun_key = NULL;
620 error = do_execute_actions(dp, skb, acts->actions,
621 acts->actions_len, false);
623 /* Check whether sub-actions looped too much. */
624 if (unlikely(loop->looping))
625 error = loop_suppress(dp, acts);
628 /* Decrement loop counter. */
630 loop->looping = false;