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>
40 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
41 struct sw_flow_key *key,
42 const struct nlattr *attr, int len);
44 static int make_writable(struct sk_buff *skb, int write_len)
46 if (!pskb_may_pull(skb, write_len))
49 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
52 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
55 /* remove VLAN header from packet and update csum accordingly. */
56 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
58 struct vlan_hdr *vhdr;
61 err = make_writable(skb, VLAN_ETH_HLEN);
65 if (skb->ip_summed == CHECKSUM_COMPLETE)
66 skb->csum = csum_sub(skb->csum, csum_partial(skb->data
67 + (2 * ETH_ALEN), VLAN_HLEN, 0));
69 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
70 *current_tci = vhdr->h_vlan_TCI;
72 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
73 __skb_pull(skb, VLAN_HLEN);
75 vlan_set_encap_proto(skb, vhdr);
76 skb->mac_header += VLAN_HLEN;
77 if (skb_network_offset(skb) < ETH_HLEN)
78 skb_set_network_header(skb, ETH_HLEN);
79 skb_reset_mac_len(skb);
84 static int pop_vlan(struct sk_buff *skb)
89 if (likely(vlan_tx_tag_present(skb))) {
92 if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
93 skb->len < VLAN_ETH_HLEN))
96 err = __pop_vlan_tci(skb, &tci);
100 /* move next vlan tag to hw accel tag */
101 if (likely(skb->protocol != htons(ETH_P_8021Q) ||
102 skb->len < VLAN_ETH_HLEN))
105 err = __pop_vlan_tci(skb, &tci);
109 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
113 static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
115 if (unlikely(vlan_tx_tag_present(skb))) {
118 /* push down current VLAN tag */
119 current_tag = vlan_tx_tag_get(skb);
121 if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
124 if (skb->ip_summed == CHECKSUM_COMPLETE)
125 skb->csum = csum_add(skb->csum, csum_partial(skb->data
126 + (2 * ETH_ALEN), VLAN_HLEN, 0));
129 __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
133 static int set_eth_addr(struct sk_buff *skb,
134 const struct ovs_key_ethernet *eth_key)
137 err = make_writable(skb, ETH_HLEN);
141 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
143 ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
144 ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);
146 ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
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);
164 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
165 inet_proto_csum_replace4(&uh->check, skb,
168 uh->check = CSUM_MANGLED_0;
173 csum_replace4(&nh->check, *addr, new_addr);
178 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
179 __be32 addr[4], const __be32 new_addr[4])
181 int transport_len = skb->len - skb_transport_offset(skb);
183 if (l4_proto == IPPROTO_TCP) {
184 if (likely(transport_len >= sizeof(struct tcphdr)))
185 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
187 } else if (l4_proto == IPPROTO_UDP) {
188 if (likely(transport_len >= sizeof(struct udphdr))) {
189 struct udphdr *uh = udp_hdr(skb);
191 if (uh->check || skb->ip_summed == CHECKSUM_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);
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 = IP6_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);
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 && skb->ip_summed != CHECKSUM_PARTIAL) {
313 set_tp_port(skb, port, new_port, &uh->check);
316 uh->check = CSUM_MANGLED_0;
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 set_sctp(struct sk_buff *skb,
364 const struct ovs_key_sctp *sctp_port_key)
368 unsigned int sctphoff = skb_transport_offset(skb);
370 err = make_writable(skb, sctphoff + sizeof(struct sctphdr));
375 if (sctp_port_key->sctp_src != sh->source ||
376 sctp_port_key->sctp_dst != sh->dest) {
377 __le32 old_correct_csum, new_csum, old_csum;
379 old_csum = sh->checksum;
380 old_correct_csum = sctp_compute_cksum(skb, sctphoff);
382 sh->source = sctp_port_key->sctp_src;
383 sh->dest = sctp_port_key->sctp_dst;
385 new_csum = sctp_compute_cksum(skb, sctphoff);
387 /* Carry any checksum errors through. */
388 sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
396 static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
403 vport = ovs_vport_rcu(dp, out_port);
404 if (unlikely(!vport)) {
409 ovs_vport_send(vport, skb);
413 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
414 struct sw_flow_key *key, const struct nlattr *attr)
416 struct dp_upcall_info upcall;
417 const struct nlattr *a;
420 upcall.cmd = OVS_PACKET_CMD_ACTION;
422 upcall.userdata = NULL;
425 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
426 a = nla_next(a, &rem)) {
427 switch (nla_type(a)) {
428 case OVS_USERSPACE_ATTR_USERDATA:
432 case OVS_USERSPACE_ATTR_PID:
433 upcall.portid = nla_get_u32(a);
438 return ovs_dp_upcall(dp, skb, &upcall);
441 static bool last_action(const struct nlattr *a, int rem)
443 return a->nla_len == rem;
446 static int sample(struct datapath *dp, struct sk_buff *skb,
447 struct sw_flow_key *key, const struct nlattr *attr)
449 const struct nlattr *acts_list = NULL;
450 const struct nlattr *a;
451 struct sk_buff *sample_skb;
454 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
455 a = nla_next(a, &rem)) {
456 switch (nla_type(a)) {
457 case OVS_SAMPLE_ATTR_PROBABILITY:
458 if (prandom_u32() >= nla_get_u32(a))
462 case OVS_SAMPLE_ATTR_ACTIONS:
468 rem = nla_len(acts_list);
469 a = nla_data(acts_list);
471 /* Actions list is either empty or only contains a single user-space
472 * action, the latter being a special case as it is the only known
473 * usage of the sample action.
474 * In these special cases don't clone the skb as there are no
475 * side-effects in the nested actions.
476 * Otherwise, clone in case the nested actions have side effects.
478 if (likely(rem == 0 || (nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
479 last_action(a, rem)))) {
483 sample_skb = skb_clone(skb, GFP_ATOMIC);
484 if (!sample_skb) /* Skip sample action when out of memory. */
488 /* Note that do_execute_actions() never consumes skb.
489 * In the case where skb has been cloned above it is the clone that
490 * is consumed. Otherwise the skb_get(skb) call prevents
491 * consumption by do_execute_actions(). Thus, it is safe to simply
492 * return the error code and let the caller (also
493 * do_execute_actions()) free skb on error.
495 return do_execute_actions(dp, sample_skb, key, a, rem);
498 static int execute_set_action(struct sk_buff *skb,
499 const struct nlattr *nested_attr)
503 switch (nla_type(nested_attr)) {
504 case OVS_KEY_ATTR_PRIORITY:
505 skb->priority = nla_get_u32(nested_attr);
508 case OVS_KEY_ATTR_SKB_MARK:
509 skb->mark = nla_get_u32(nested_attr);
512 case OVS_KEY_ATTR_IPV4_TUNNEL:
513 OVS_CB(skb)->tun_key = nla_data(nested_attr);
516 case OVS_KEY_ATTR_ETHERNET:
517 err = set_eth_addr(skb, nla_data(nested_attr));
520 case OVS_KEY_ATTR_IPV4:
521 err = set_ipv4(skb, nla_data(nested_attr));
524 case OVS_KEY_ATTR_IPV6:
525 err = set_ipv6(skb, nla_data(nested_attr));
528 case OVS_KEY_ATTR_TCP:
529 err = set_tcp(skb, nla_data(nested_attr));
532 case OVS_KEY_ATTR_UDP:
533 err = set_udp(skb, nla_data(nested_attr));
536 case OVS_KEY_ATTR_SCTP:
537 err = set_sctp(skb, nla_data(nested_attr));
544 /* Execute a list of actions against 'skb'. */
545 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
546 struct sw_flow_key *key,
547 const struct nlattr *attr, int len)
549 /* Every output action needs a separate clone of 'skb', but the common
550 * case is just a single output action, so that doing a clone and
551 * then freeing the original skbuff is wasteful. So the following code
552 * is slightly obscure just to avoid that. */
554 const struct nlattr *a;
557 for (a = attr, rem = len; rem > 0;
558 a = nla_next(a, &rem)) {
561 if (prev_port != -1) {
562 do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
566 switch (nla_type(a)) {
567 case OVS_ACTION_ATTR_OUTPUT:
568 prev_port = nla_get_u32(a);
571 case OVS_ACTION_ATTR_USERSPACE:
572 output_userspace(dp, skb, key, a);
575 case OVS_ACTION_ATTR_PUSH_VLAN:
576 err = push_vlan(skb, nla_data(a));
577 if (unlikely(err)) /* skb already freed. */
581 case OVS_ACTION_ATTR_POP_VLAN:
585 case OVS_ACTION_ATTR_SET:
586 err = execute_set_action(skb, nla_data(a));
589 case OVS_ACTION_ATTR_SAMPLE:
590 err = sample(dp, skb, key, a);
591 if (unlikely(err)) /* skb already freed. */
603 do_output(dp, skb, prev_port);
610 /* Execute a list of actions against 'skb'. */
611 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
612 struct sw_flow_key *key)
614 struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
616 OVS_CB(skb)->tun_key = NULL;
617 return do_execute_actions(dp, skb, key,
618 acts->actions, acts->actions_len);