2 * Copyright (c) 2007-2014 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>
43 static void flow_key_clone(struct sk_buff *skb, struct sw_flow_key *new_key)
45 *new_key = *OVS_CB(skb)->pkt_key;
46 OVS_CB(skb)->pkt_key = new_key;
49 static void flow_key_set_recirc_id(struct sk_buff *skb, u32 recirc_id)
51 OVS_CB(skb)->pkt_key->recirc_id = recirc_id;
54 static void flow_key_set_priority(struct sk_buff *skb, u32 priority)
56 OVS_CB(skb)->pkt_key->phy.priority = priority;
59 static void flow_key_set_skb_mark(struct sk_buff *skb, u32 skb_mark)
61 OVS_CB(skb)->pkt_key->phy.skb_mark = skb_mark;
64 static void flow_key_set_eth_src(struct sk_buff *skb, const u8 addr[])
66 ether_addr_copy(OVS_CB(skb)->pkt_key->eth.src, addr);
69 static void flow_key_set_eth_dst(struct sk_buff *skb, const u8 addr[])
71 ether_addr_copy(OVS_CB(skb)->pkt_key->eth.dst, addr);
74 static void flow_key_set_vlan_tci(struct sk_buff *skb, __be16 tci)
76 OVS_CB(skb)->pkt_key->eth.tci = tci;
79 static void flow_key_set_mpls_top_lse(struct sk_buff *skb, __be32 top_lse)
81 OVS_CB(skb)->pkt_key->mpls.top_lse = top_lse;
84 static void flow_key_set_ipv4_src(struct sk_buff *skb, __be32 addr)
86 OVS_CB(skb)->pkt_key->ipv4.addr.src = addr;
89 static void flow_key_set_ipv4_dst(struct sk_buff *skb, __be32 addr)
91 OVS_CB(skb)->pkt_key->ipv4.addr.src = addr;
94 static void flow_key_set_ip_tos(struct sk_buff *skb, u8 tos)
96 OVS_CB(skb)->pkt_key->ip.tos = tos;
99 static void flow_key_set_ip_ttl(struct sk_buff *skb, u8 ttl)
101 OVS_CB(skb)->pkt_key->ip.ttl = ttl;
104 static void flow_key_set_ipv6_src(struct sk_buff *skb,
105 const __be32 addr[4])
107 memcpy(&OVS_CB(skb)->pkt_key->ipv6.addr.src, addr, sizeof(__be32[4]));
110 static void flow_key_set_ipv6_dst(struct sk_buff *skb,
111 const __be32 addr[4])
113 memcpy(&OVS_CB(skb)->pkt_key->ipv6.addr.dst, addr, sizeof(__be32[4]));
116 static void flow_key_set_ipv6_fl(struct sk_buff *skb,
117 const struct ipv6hdr *nh)
119 OVS_CB(skb)->pkt_key->ipv6.label = *(__be32 *)nh &
120 htonl(IPV6_FLOWINFO_FLOWLABEL);
123 static void flow_key_set_tp_src(struct sk_buff *skb, __be16 port)
125 OVS_CB(skb)->pkt_key->tp.src = port;
128 static void flow_key_set_tp_dst(struct sk_buff *skb, __be16 port)
130 OVS_CB(skb)->pkt_key->tp.dst = port;
133 static void invalidate_skb_flow_key(struct sk_buff *skb)
135 OVS_CB(skb)->pkt_key->eth.type = htons(0);
138 static bool is_skb_flow_key_valid(struct sk_buff *skb)
140 return !!OVS_CB(skb)->pkt_key->eth.type;
143 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
144 const struct nlattr *attr, int len);
146 static int make_writable(struct sk_buff *skb, int write_len)
148 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
151 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
154 /* The end of the mac header.
156 * For non-MPLS skbs this will correspond to the network header.
157 * For MPLS skbs it will be before the network_header as the MPLS
158 * label stack lies between the end of the mac header and the network
159 * header. That is, for MPLS skbs the end of the mac header
160 * is the top of the MPLS label stack.
162 static unsigned char *mac_header_end(const struct sk_buff *skb)
164 return skb_mac_header(skb) + skb->mac_len;
167 static int push_mpls(struct sk_buff *skb,
168 const struct ovs_action_push_mpls *mpls)
170 __be32 *new_mpls_lse;
173 if (skb_cow_head(skb, MPLS_HLEN) < 0)
176 skb_push(skb, MPLS_HLEN);
177 memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
179 skb_reset_mac_header(skb);
181 new_mpls_lse = (__be32 *)mac_header_end(skb);
182 *new_mpls_lse = mpls->mpls_lse;
184 if (skb->ip_summed == CHECKSUM_COMPLETE)
185 skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse,
189 hdr->h_proto = mpls->mpls_ethertype;
190 if (!ovs_skb_get_inner_protocol(skb))
191 ovs_skb_set_inner_protocol(skb, skb->protocol);
192 skb->protocol = mpls->mpls_ethertype;
193 invalidate_skb_flow_key(skb);
197 static int pop_mpls(struct sk_buff *skb, const __be16 ethertype)
202 err = make_writable(skb, skb->mac_len + MPLS_HLEN);
206 if (skb->ip_summed == CHECKSUM_COMPLETE)
207 skb->csum = csum_sub(skb->csum,
208 csum_partial(mac_header_end(skb),
211 memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
214 __skb_pull(skb, MPLS_HLEN);
215 skb_reset_mac_header(skb);
217 /* mac_header_end() is used to locate the ethertype
218 * field correctly in the presence of VLAN tags.
220 hdr = (struct ethhdr *)(mac_header_end(skb) - ETH_HLEN);
221 hdr->h_proto = ethertype;
222 if (eth_p_mpls(skb->protocol))
223 skb->protocol = ethertype;
224 invalidate_skb_flow_key(skb);
228 static int set_mpls(struct sk_buff *skb, const __be32 *mpls_lse)
230 __be32 *stack = (__be32 *)mac_header_end(skb);
233 err = make_writable(skb, skb->mac_len + MPLS_HLEN);
237 if (skb->ip_summed == CHECKSUM_COMPLETE) {
238 __be32 diff[] = { ~(*stack), *mpls_lse };
239 skb->csum = ~csum_partial((char *)diff, sizeof(diff),
244 flow_key_set_mpls_top_lse(skb, *stack);
248 /* remove VLAN header from packet and update csum accordingly. */
249 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
251 struct vlan_hdr *vhdr;
254 err = make_writable(skb, VLAN_ETH_HLEN);
258 if (skb->ip_summed == CHECKSUM_COMPLETE)
259 skb->csum = csum_sub(skb->csum, csum_partial(skb->data
260 + (2 * ETH_ALEN), VLAN_HLEN, 0));
262 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
263 *current_tci = vhdr->h_vlan_TCI;
265 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
266 __skb_pull(skb, VLAN_HLEN);
268 vlan_set_encap_proto(skb, vhdr);
269 skb->mac_header += VLAN_HLEN;
270 /* Update mac_len for subsequent MPLS actions */
271 skb->mac_len -= VLAN_HLEN;
276 static int pop_vlan(struct sk_buff *skb)
281 if (likely(vlan_tx_tag_present(skb))) {
282 vlan_set_tci(skb, 0);
284 if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
285 skb->len < VLAN_ETH_HLEN))
288 err = __pop_vlan_tci(skb, &tci);
292 /* move next vlan tag to hw accel tag */
293 if (likely(skb->protocol != htons(ETH_P_8021Q) ||
294 skb->len < VLAN_ETH_HLEN)) {
295 flow_key_set_vlan_tci(skb, 0);
299 invalidate_skb_flow_key(skb);
300 err = __pop_vlan_tci(skb, &tci);
304 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
308 static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
310 if (unlikely(vlan_tx_tag_present(skb))) {
313 /* push down current VLAN tag */
314 current_tag = vlan_tx_tag_get(skb);
316 if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
319 /* Update mac_len for subsequent MPLS actions */
320 skb->mac_len += VLAN_HLEN;
322 if (skb->ip_summed == CHECKSUM_COMPLETE)
323 skb->csum = csum_add(skb->csum, csum_partial(skb->data
324 + (2 * ETH_ALEN), VLAN_HLEN, 0));
326 invalidate_skb_flow_key(skb);
328 flow_key_set_vlan_tci(skb, vlan->vlan_tci);
330 __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
334 static int set_eth_addr(struct sk_buff *skb,
335 const struct ovs_key_ethernet *eth_key)
338 err = make_writable(skb, ETH_HLEN);
342 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
344 ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
345 ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);
347 ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
349 flow_key_set_eth_src(skb, eth_key->eth_src);
350 flow_key_set_eth_dst(skb, eth_key->eth_dst);
354 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
355 __be32 *addr, __be32 new_addr)
357 int transport_len = skb->len - skb_transport_offset(skb);
359 if (nh->protocol == IPPROTO_TCP) {
360 if (likely(transport_len >= sizeof(struct tcphdr)))
361 inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
363 } else if (nh->protocol == IPPROTO_UDP) {
364 if (likely(transport_len >= sizeof(struct udphdr))) {
365 struct udphdr *uh = udp_hdr(skb);
367 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
368 inet_proto_csum_replace4(&uh->check, skb,
371 uh->check = CSUM_MANGLED_0;
376 csum_replace4(&nh->check, *addr, new_addr);
381 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
382 __be32 addr[4], const __be32 new_addr[4])
384 int transport_len = skb->len - skb_transport_offset(skb);
386 if (l4_proto == IPPROTO_TCP) {
387 if (likely(transport_len >= sizeof(struct tcphdr)))
388 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
390 } else if (l4_proto == IPPROTO_UDP) {
391 if (likely(transport_len >= sizeof(struct udphdr))) {
392 struct udphdr *uh = udp_hdr(skb);
394 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
395 inet_proto_csum_replace16(&uh->check, skb,
398 uh->check = CSUM_MANGLED_0;
404 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
405 __be32 addr[4], const __be32 new_addr[4],
406 bool recalculate_csum)
408 if (likely(recalculate_csum))
409 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
412 memcpy(addr, new_addr, sizeof(__be32[4]));
415 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
417 nh->priority = tc >> 4;
418 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
421 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
423 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
424 nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
425 nh->flow_lbl[2] = fl & 0x000000FF;
428 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
430 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
434 static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
439 err = make_writable(skb, skb_network_offset(skb) +
440 sizeof(struct iphdr));
446 if (ipv4_key->ipv4_src != nh->saddr) {
447 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
448 flow_key_set_ipv4_src(skb, ipv4_key->ipv4_src);
451 if (ipv4_key->ipv4_dst != nh->daddr) {
452 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
453 flow_key_set_ipv4_dst(skb, ipv4_key->ipv4_dst);
456 if (ipv4_key->ipv4_tos != nh->tos) {
457 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
458 flow_key_set_ip_tos(skb, nh->tos);
461 if (ipv4_key->ipv4_ttl != nh->ttl) {
462 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
463 flow_key_set_ip_ttl(skb, ipv4_key->ipv4_ttl);
469 static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
476 err = make_writable(skb, skb_network_offset(skb) +
477 sizeof(struct ipv6hdr));
482 saddr = (__be32 *)&nh->saddr;
483 daddr = (__be32 *)&nh->daddr;
485 if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) {
486 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
487 ipv6_key->ipv6_src, true);
488 flow_key_set_ipv6_src(skb, ipv6_key->ipv6_src);
491 if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
492 unsigned int offset = 0;
493 int flags = OVS_IP6T_FH_F_SKIP_RH;
494 bool recalc_csum = true;
496 if (ipv6_ext_hdr(nh->nexthdr))
497 recalc_csum = ipv6_find_hdr(skb, &offset,
498 NEXTHDR_ROUTING, NULL,
499 &flags) != NEXTHDR_ROUTING;
501 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
502 ipv6_key->ipv6_dst, recalc_csum);
503 flow_key_set_ipv6_dst(skb, ipv6_key->ipv6_dst);
506 set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
507 flow_key_set_ip_tos(skb, ipv6_get_dsfield(nh));
509 set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
510 flow_key_set_ipv6_fl(skb, nh);
512 nh->hop_limit = ipv6_key->ipv6_hlimit;
513 flow_key_set_ip_ttl(skb, ipv6_key->ipv6_hlimit);
517 /* Must follow make_writable() since that can move the skb data. */
518 static void set_tp_port(struct sk_buff *skb, __be16 *port,
519 __be16 new_port, __sum16 *check)
521 inet_proto_csum_replace2(check, skb, *port, new_port, 0);
526 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
528 struct udphdr *uh = udp_hdr(skb);
530 if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
531 set_tp_port(skb, port, new_port, &uh->check);
534 uh->check = CSUM_MANGLED_0;
541 static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
546 err = make_writable(skb, skb_transport_offset(skb) +
547 sizeof(struct udphdr));
552 if (udp_port_key->udp_src != uh->source) {
553 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
554 flow_key_set_tp_src(skb, udp_port_key->udp_src);
557 if (udp_port_key->udp_dst != uh->dest) {
558 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
559 flow_key_set_tp_dst(skb, udp_port_key->udp_dst);
565 static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
570 err = make_writable(skb, skb_transport_offset(skb) +
571 sizeof(struct tcphdr));
576 if (tcp_port_key->tcp_src != th->source) {
577 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
578 flow_key_set_tp_src(skb, tcp_port_key->tcp_src);
581 if (tcp_port_key->tcp_dst != th->dest) {
582 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
583 flow_key_set_tp_dst(skb, tcp_port_key->tcp_dst);
589 static int set_sctp(struct sk_buff *skb,
590 const struct ovs_key_sctp *sctp_port_key)
594 unsigned int sctphoff = skb_transport_offset(skb);
596 err = make_writable(skb, sctphoff + sizeof(struct sctphdr));
601 if (sctp_port_key->sctp_src != sh->source ||
602 sctp_port_key->sctp_dst != sh->dest) {
603 __le32 old_correct_csum, new_csum, old_csum;
605 old_csum = sh->checksum;
606 old_correct_csum = sctp_compute_cksum(skb, sctphoff);
608 sh->source = sctp_port_key->sctp_src;
609 sh->dest = sctp_port_key->sctp_dst;
611 new_csum = sctp_compute_cksum(skb, sctphoff);
613 /* Carry any checksum errors through. */
614 sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
617 flow_key_set_tp_src(skb, sctp_port_key->sctp_src);
618 flow_key_set_tp_dst(skb, sctp_port_key->sctp_dst);
624 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
626 struct vport *vport = ovs_vport_rcu(dp, out_port);
629 ovs_vport_send(vport, skb);
634 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
635 const struct nlattr *attr)
637 struct dp_upcall_info upcall;
638 const struct nlattr *a;
640 struct ovs_tunnel_info info;
642 upcall.cmd = OVS_PACKET_CMD_ACTION;
643 upcall.userdata = NULL;
645 upcall.egress_tun_info = NULL;
647 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
648 a = nla_next(a, &rem)) {
649 switch (nla_type(a)) {
650 case OVS_USERSPACE_ATTR_USERDATA:
654 case OVS_USERSPACE_ATTR_PID:
655 upcall.portid = nla_get_u32(a);
658 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
659 /* Get out tunnel info. */
662 vport = ovs_vport_rcu(dp, nla_get_u32(a));
666 err = ovs_vport_get_egress_tun_info(vport, skb,
669 upcall.egress_tun_info = &info;
674 } /* End of switch. */
677 return ovs_dp_upcall(dp, skb, &upcall);
680 static bool last_action(const struct nlattr *a, int rem)
682 return a->nla_len == rem;
685 static int sample(struct datapath *dp, struct sk_buff *skb,
686 const struct nlattr *attr)
688 struct sw_flow_key sample_key;
689 const struct nlattr *acts_list = NULL;
690 const struct nlattr *a;
691 struct sk_buff *sample_skb;
694 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
695 a = nla_next(a, &rem)) {
696 switch (nla_type(a)) {
697 case OVS_SAMPLE_ATTR_PROBABILITY:
698 if (prandom_u32() >= nla_get_u32(a))
702 case OVS_SAMPLE_ATTR_ACTIONS:
708 rem = nla_len(acts_list);
709 a = nla_data(acts_list);
711 /* Actions list is either empty or only contains a single user-space
712 * action, the latter being a special case as it is the only known
713 * usage of the sample action.
714 * In these special cases don't clone the skb as there are no
715 * side-effects in the nested actions.
716 * Otherwise, clone in case the nested actions have side effects. */
717 if (likely(rem == 0 ||
718 (nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
719 last_action(a, rem)))) {
723 sample_skb = skb_clone(skb, GFP_ATOMIC);
725 /* Skip the sample action when out of memory. */
728 flow_key_clone(skb, &sample_key);
731 /* Note that do_execute_actions() never consumes skb.
732 * In the case where skb has been cloned above it is the clone that
733 * is consumed. Otherwise the skb_get(skb) call prevents
734 * consumption by do_execute_actions(). Thus, it is safe to simply
735 * return the error code and let the caller (also
736 * do_execute_actions()) free skb on error. */
737 return do_execute_actions(dp, sample_skb, a, rem);
740 static void execute_hash(struct sk_buff *skb, const struct nlattr *attr)
742 struct sw_flow_key *key = OVS_CB(skb)->pkt_key;
743 struct ovs_action_hash *hash_act = nla_data(attr);
746 /* OVS_HASH_ALG_L4 is the only possible hash algorithm. */
747 hash = skb_get_hash(skb);
748 hash = jhash_1word(hash, hash_act->hash_basis);
752 key->ovs_flow_hash = hash;
755 static int execute_set_action(struct sk_buff *skb,
756 const struct nlattr *nested_attr)
760 switch (nla_type(nested_attr)) {
761 case OVS_KEY_ATTR_PRIORITY:
762 skb->priority = nla_get_u32(nested_attr);
763 flow_key_set_priority(skb, skb->priority);
766 case OVS_KEY_ATTR_SKB_MARK:
767 skb->mark = nla_get_u32(nested_attr);
768 flow_key_set_skb_mark(skb, skb->mark);
771 case OVS_KEY_ATTR_TUNNEL_INFO:
772 OVS_CB(skb)->egress_tun_info = nla_data(nested_attr);
775 case OVS_KEY_ATTR_ETHERNET:
776 err = set_eth_addr(skb, nla_data(nested_attr));
779 case OVS_KEY_ATTR_IPV4:
780 err = set_ipv4(skb, nla_data(nested_attr));
783 case OVS_KEY_ATTR_IPV6:
784 err = set_ipv6(skb, nla_data(nested_attr));
787 case OVS_KEY_ATTR_TCP:
788 err = set_tcp(skb, nla_data(nested_attr));
791 case OVS_KEY_ATTR_UDP:
792 err = set_udp(skb, nla_data(nested_attr));
795 case OVS_KEY_ATTR_SCTP:
796 err = set_sctp(skb, nla_data(nested_attr));
799 case OVS_KEY_ATTR_MPLS:
800 err = set_mpls(skb, nla_data(nested_attr));
808 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
809 const struct nlattr *a, int rem)
811 struct sw_flow_key recirc_key;
814 if (!last_action(a, rem)) {
815 /* Recirc action is the not the last action
816 * of the action list. */
817 skb = skb_clone(skb, GFP_ATOMIC);
819 /* Skip the recirc action when out of memory, but
820 * continue on with the rest of the action list. */
825 if (!is_skb_flow_key_valid(skb)) {
826 err = ovs_flow_key_update(skb, OVS_CB(skb)->pkt_key);
832 BUG_ON(!is_skb_flow_key_valid(skb));
834 if (!last_action(a, rem))
835 flow_key_clone(skb, &recirc_key);
837 flow_key_set_recirc_id(skb, nla_get_u32(a));
838 ovs_dp_process_packet(skb, true);
842 /* Execute a list of actions against 'skb'. */
843 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
844 const struct nlattr *attr, int len)
846 /* Every output action needs a separate clone of 'skb', but the common
847 * case is just a single output action, so that doing a clone and
848 * then freeing the original skbuff is wasteful. So the following code
849 * is slightly obscure just to avoid that. */
851 const struct nlattr *a;
854 for (a = attr, rem = len; rem > 0;
855 a = nla_next(a, &rem)) {
858 if (unlikely(prev_port != -1)) {
859 struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
862 do_output(dp, out_skb, prev_port);
867 switch (nla_type(a)) {
868 case OVS_ACTION_ATTR_OUTPUT:
869 prev_port = nla_get_u32(a);
872 case OVS_ACTION_ATTR_USERSPACE:
873 output_userspace(dp, skb, a);
876 case OVS_ACTION_ATTR_HASH:
877 execute_hash(skb, a);
880 case OVS_ACTION_ATTR_PUSH_MPLS:
881 err = push_mpls(skb, nla_data(a));
884 case OVS_ACTION_ATTR_POP_MPLS:
885 err = pop_mpls(skb, nla_get_be16(a));
888 case OVS_ACTION_ATTR_PUSH_VLAN:
889 err = push_vlan(skb, nla_data(a));
890 if (unlikely(err)) /* skb already freed. */
894 case OVS_ACTION_ATTR_POP_VLAN:
898 case OVS_ACTION_ATTR_RECIRC:
899 err = execute_recirc(dp, skb, a, rem);
902 case OVS_ACTION_ATTR_SET:
903 err = execute_set_action(skb, nla_data(a));
906 case OVS_ACTION_ATTR_SAMPLE:
907 err = sample(dp, skb, a);
918 do_output(dp, skb, prev_port);
925 /* We limit the number of times that we pass into execute_actions()
926 * to avoid blowing out the stack in the event that we have a loop.
928 * Each loop adds some (estimated) cost to the kernel stack.
929 * The loop terminates when the max cost is exceeded.
931 #define RECIRC_STACK_COST 1
932 #define DEFAULT_STACK_COST 4
933 /* Allow up to 4 regular services, and up to 3 recirculations */
934 #define MAX_STACK_COST (DEFAULT_STACK_COST * 4 + RECIRC_STACK_COST * 3)
936 struct loop_counter {
937 u8 stack_cost; /* loop stack cost. */
938 bool looping; /* Loop detected? */
941 static DEFINE_PER_CPU(struct loop_counter, loop_counters);
943 static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions)
946 pr_warn("%s: flow loop detected, dropping\n",
948 actions->actions_len = 0;
952 /* Execute a list of actions against 'skb'. */
953 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
954 struct sw_flow_actions *acts, bool recirc)
956 const u8 stack_cost = recirc ? RECIRC_STACK_COST : DEFAULT_STACK_COST;
957 struct loop_counter *loop;
960 /* Check whether we've looped too much. */
961 loop = &__get_cpu_var(loop_counters);
962 loop->stack_cost += stack_cost;
963 if (unlikely(loop->stack_cost > MAX_STACK_COST))
964 loop->looping = true;
965 if (unlikely(loop->looping)) {
966 error = loop_suppress(dp, acts);
971 error = do_execute_actions(dp, skb, acts->actions, acts->actions_len);
973 /* Check whether sub-actions looped too much. */
974 if (unlikely(loop->looping))
975 error = loop_suppress(dp, acts);
978 /* Decrement loop stack cost. */
979 loop->stack_cost -= stack_cost;
980 if (!loop->stack_cost)
981 loop->looping = false;