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>
38 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
39 const struct nlattr *attr, int len, bool keep_skb);
41 static int make_writable(struct sk_buff *skb, int write_len)
43 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
46 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
49 /* remove VLAN header from packet and update csum accordingly. */
50 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
52 struct vlan_hdr *vhdr;
55 err = make_writable(skb, VLAN_ETH_HLEN);
59 if (skb->ip_summed == CHECKSUM_COMPLETE)
60 skb->csum = csum_sub(skb->csum, csum_partial(skb->data
61 + (2 * ETH_ALEN), VLAN_HLEN, 0));
63 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
64 *current_tci = vhdr->h_vlan_TCI;
66 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
67 __skb_pull(skb, VLAN_HLEN);
69 vlan_set_encap_proto(skb, vhdr);
70 skb->mac_header += VLAN_HLEN;
71 skb_reset_mac_len(skb);
76 static int pop_vlan(struct sk_buff *skb)
81 if (likely(vlan_tx_tag_present(skb))) {
84 if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
85 skb->len < VLAN_ETH_HLEN))
88 err = __pop_vlan_tci(skb, &tci);
92 /* move next vlan tag to hw accel tag */
93 if (likely(skb->protocol != htons(ETH_P_8021Q) ||
94 skb->len < VLAN_ETH_HLEN))
97 err = __pop_vlan_tci(skb, &tci);
101 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
105 static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
107 if (unlikely(vlan_tx_tag_present(skb))) {
110 /* push down current VLAN tag */
111 current_tag = vlan_tx_tag_get(skb);
113 if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
116 if (skb->ip_summed == CHECKSUM_COMPLETE)
117 skb->csum = csum_add(skb->csum, csum_partial(skb->data
118 + (2 * ETH_ALEN), VLAN_HLEN, 0));
121 __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
125 static int set_eth_addr(struct sk_buff *skb,
126 const struct ovs_key_ethernet *eth_key)
129 err = make_writable(skb, ETH_HLEN);
133 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
135 memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
136 memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
138 ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
143 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
144 __be32 *addr, __be32 new_addr)
146 int transport_len = skb->len - skb_transport_offset(skb);
148 if (nh->protocol == IPPROTO_TCP) {
149 if (likely(transport_len >= sizeof(struct tcphdr)))
150 inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
152 } else if (nh->protocol == IPPROTO_UDP) {
153 if (likely(transport_len >= sizeof(struct udphdr))) {
154 struct udphdr *uh = udp_hdr(skb);
156 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
157 inet_proto_csum_replace4(&uh->check, skb,
160 uh->check = CSUM_MANGLED_0;
165 csum_replace4(&nh->check, *addr, new_addr);
170 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
171 __be32 addr[4], const __be32 new_addr[4])
173 int transport_len = skb->len - skb_transport_offset(skb);
175 if (l4_proto == IPPROTO_TCP) {
176 if (likely(transport_len >= sizeof(struct tcphdr)))
177 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
179 } else if (l4_proto == IPPROTO_UDP) {
180 if (likely(transport_len >= sizeof(struct udphdr))) {
181 struct udphdr *uh = udp_hdr(skb);
183 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
184 inet_proto_csum_replace16(&uh->check, skb,
187 uh->check = CSUM_MANGLED_0;
193 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
194 __be32 addr[4], const __be32 new_addr[4],
195 bool recalculate_csum)
197 if (recalculate_csum)
198 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
201 memcpy(addr, new_addr, sizeof(__be32[4]));
204 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
206 nh->priority = tc >> 4;
207 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
210 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
212 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
213 nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
214 nh->flow_lbl[2] = fl & 0x000000FF;
217 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
219 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
223 static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
228 err = make_writable(skb, skb_network_offset(skb) +
229 sizeof(struct iphdr));
235 if (ipv4_key->ipv4_src != nh->saddr)
236 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
238 if (ipv4_key->ipv4_dst != nh->daddr)
239 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
241 if (ipv4_key->ipv4_tos != nh->tos)
242 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
244 if (ipv4_key->ipv4_ttl != nh->ttl)
245 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
250 static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
257 err = make_writable(skb, skb_network_offset(skb) +
258 sizeof(struct ipv6hdr));
263 saddr = (__be32 *)&nh->saddr;
264 daddr = (__be32 *)&nh->daddr;
266 if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
267 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
268 ipv6_key->ipv6_src, true);
270 if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
271 unsigned int offset = 0;
272 int flags = IP6_FH_F_SKIP_RH;
273 bool recalc_csum = true;
275 if (ipv6_ext_hdr(nh->nexthdr))
276 recalc_csum = ipv6_find_hdr(skb, &offset,
277 NEXTHDR_ROUTING, NULL,
278 &flags) != NEXTHDR_ROUTING;
280 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
281 ipv6_key->ipv6_dst, recalc_csum);
284 set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
285 set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
286 nh->hop_limit = ipv6_key->ipv6_hlimit;
291 /* Must follow make_writable() since that can move the skb data. */
292 static void set_tp_port(struct sk_buff *skb, __be16 *port,
293 __be16 new_port, __sum16 *check)
295 inet_proto_csum_replace2(check, skb, *port, new_port, 0);
300 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
302 struct udphdr *uh = udp_hdr(skb);
304 if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
305 set_tp_port(skb, port, new_port, &uh->check);
308 uh->check = CSUM_MANGLED_0;
315 static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
320 err = make_writable(skb, skb_transport_offset(skb) +
321 sizeof(struct udphdr));
326 if (udp_port_key->udp_src != uh->source)
327 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
329 if (udp_port_key->udp_dst != uh->dest)
330 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
335 static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
340 err = make_writable(skb, skb_transport_offset(skb) +
341 sizeof(struct tcphdr));
346 if (tcp_port_key->tcp_src != th->source)
347 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
349 if (tcp_port_key->tcp_dst != th->dest)
350 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
355 static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
362 vport = ovs_vport_rcu(dp, out_port);
363 if (unlikely(!vport)) {
368 ovs_vport_send(vport, skb);
372 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
373 const struct nlattr *attr)
375 struct dp_upcall_info upcall;
376 const struct nlattr *a;
379 upcall.cmd = OVS_PACKET_CMD_ACTION;
380 upcall.key = &OVS_CB(skb)->flow->key;
381 upcall.userdata = NULL;
384 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
385 a = nla_next(a, &rem)) {
386 switch (nla_type(a)) {
387 case OVS_USERSPACE_ATTR_USERDATA:
391 case OVS_USERSPACE_ATTR_PID:
392 upcall.portid = nla_get_u32(a);
397 return ovs_dp_upcall(dp, skb, &upcall);
400 static int sample(struct datapath *dp, struct sk_buff *skb,
401 const struct nlattr *attr)
403 const struct nlattr *acts_list = NULL;
404 const struct nlattr *a;
407 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
408 a = nla_next(a, &rem)) {
409 switch (nla_type(a)) {
410 case OVS_SAMPLE_ATTR_PROBABILITY:
411 if (net_random() >= nla_get_u32(a))
415 case OVS_SAMPLE_ATTR_ACTIONS:
421 return do_execute_actions(dp, skb, nla_data(acts_list),
422 nla_len(acts_list), true);
425 static int execute_set_action(struct sk_buff *skb,
426 const struct nlattr *nested_attr)
430 switch (nla_type(nested_attr)) {
431 case OVS_KEY_ATTR_PRIORITY:
432 skb->priority = nla_get_u32(nested_attr);
435 case OVS_KEY_ATTR_SKB_MARK:
436 skb->mark = nla_get_u32(nested_attr);
439 case OVS_KEY_ATTR_IPV4_TUNNEL:
440 OVS_CB(skb)->tun_key = nla_data(nested_attr);
443 case OVS_KEY_ATTR_ETHERNET:
444 err = set_eth_addr(skb, nla_data(nested_attr));
447 case OVS_KEY_ATTR_IPV4:
448 err = set_ipv4(skb, nla_data(nested_attr));
451 case OVS_KEY_ATTR_IPV6:
452 err = set_ipv6(skb, nla_data(nested_attr));
455 case OVS_KEY_ATTR_TCP:
456 err = set_tcp(skb, nla_data(nested_attr));
459 case OVS_KEY_ATTR_UDP:
460 err = set_udp(skb, nla_data(nested_attr));
467 /* Execute a list of actions against 'skb'. */
468 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
469 const struct nlattr *attr, int len, bool keep_skb)
471 /* Every output action needs a separate clone of 'skb', but the common
472 * case is just a single output action, so that doing a clone and
473 * then freeing the original skbuff is wasteful. So the following code
474 * is slightly obscure just to avoid that. */
476 const struct nlattr *a;
479 for (a = attr, rem = len; rem > 0;
480 a = nla_next(a, &rem)) {
483 if (prev_port != -1) {
484 do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
488 switch (nla_type(a)) {
489 case OVS_ACTION_ATTR_OUTPUT:
490 prev_port = nla_get_u32(a);
493 case OVS_ACTION_ATTR_USERSPACE:
494 output_userspace(dp, skb, a);
497 case OVS_ACTION_ATTR_PUSH_VLAN:
498 err = push_vlan(skb, nla_data(a));
499 if (unlikely(err)) /* skb already freed. */
503 case OVS_ACTION_ATTR_POP_VLAN:
507 case OVS_ACTION_ATTR_SET:
508 err = execute_set_action(skb, nla_data(a));
511 case OVS_ACTION_ATTR_SAMPLE:
512 err = sample(dp, skb, a);
522 if (prev_port != -1) {
524 skb = skb_clone(skb, GFP_ATOMIC);
526 do_output(dp, skb, prev_port);
527 } else if (!keep_skb)
533 /* Execute a list of actions against 'skb'. */
534 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
536 struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
538 return do_execute_actions(dp, skb, acts->actions,
539 acts->actions_len, false);