2 * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <sys/types.h>
22 #include <netinet/in.h>
23 #include <netinet/icmp6.h>
24 #include <netinet/ip6.h>
27 #include "byte-order.h"
30 #include "dynamic-string.h"
33 #include "openflow/openflow.h"
35 #include "unaligned.h"
38 VLOG_DEFINE_THIS_MODULE(flow);
40 COVERAGE_DEFINE(flow_extract);
42 static struct arp_eth_header *
43 pull_arp(struct ofpbuf *packet)
45 return ofpbuf_try_pull(packet, ARP_ETH_HEADER_LEN);
48 static struct ip_header *
49 pull_ip(struct ofpbuf *packet)
51 if (packet->size >= IP_HEADER_LEN) {
52 struct ip_header *ip = packet->data;
53 int ip_len = IP_IHL(ip->ip_ihl_ver) * 4;
54 if (ip_len >= IP_HEADER_LEN && packet->size >= ip_len) {
55 return ofpbuf_pull(packet, ip_len);
61 static struct tcp_header *
62 pull_tcp(struct ofpbuf *packet)
64 if (packet->size >= TCP_HEADER_LEN) {
65 struct tcp_header *tcp = packet->data;
66 int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
67 if (tcp_len >= TCP_HEADER_LEN && packet->size >= tcp_len) {
68 return ofpbuf_pull(packet, tcp_len);
74 static struct udp_header *
75 pull_udp(struct ofpbuf *packet)
77 return ofpbuf_try_pull(packet, UDP_HEADER_LEN);
80 static struct icmp_header *
81 pull_icmp(struct ofpbuf *packet)
83 return ofpbuf_try_pull(packet, ICMP_HEADER_LEN);
86 static struct icmp6_hdr *
87 pull_icmpv6(struct ofpbuf *packet)
89 return ofpbuf_try_pull(packet, sizeof(struct icmp6_hdr));
93 parse_vlan(struct ofpbuf *b, struct flow *flow)
96 ovs_be16 eth_type; /* ETH_TYPE_VLAN */
100 if (b->size >= sizeof(struct qtag_prefix) + sizeof(ovs_be16)) {
101 struct qtag_prefix *qp = ofpbuf_pull(b, sizeof *qp);
102 flow->vlan_tci = qp->tci | htons(VLAN_CFI);
107 parse_ethertype(struct ofpbuf *b)
109 struct llc_snap_header *llc;
112 proto = *(ovs_be16 *) ofpbuf_pull(b, sizeof proto);
113 if (ntohs(proto) >= ETH_TYPE_MIN) {
117 if (b->size < sizeof *llc) {
118 return htons(FLOW_DL_TYPE_NONE);
122 if (llc->llc.llc_dsap != LLC_DSAP_SNAP
123 || llc->llc.llc_ssap != LLC_SSAP_SNAP
124 || llc->llc.llc_cntl != LLC_CNTL_SNAP
125 || memcmp(llc->snap.snap_org, SNAP_ORG_ETHERNET,
126 sizeof llc->snap.snap_org)) {
127 return htons(FLOW_DL_TYPE_NONE);
130 ofpbuf_pull(b, sizeof *llc);
131 return llc->snap.snap_type;
135 parse_ipv6(struct ofpbuf *packet, struct flow *flow)
137 const struct ip6_hdr *nh;
141 nh = ofpbuf_try_pull(packet, sizeof *nh);
146 nexthdr = nh->ip6_nxt;
148 flow->ipv6_src = nh->ip6_src;
149 flow->ipv6_dst = nh->ip6_dst;
151 tc_flow = get_unaligned_be32(&nh->ip6_flow);
152 flow->nw_tos = ntohl(tc_flow) >> 20;
153 flow->ipv6_label = tc_flow & htonl(IPV6_LABEL_MASK);
154 flow->nw_ttl = nh->ip6_hlim;
155 flow->nw_proto = IPPROTO_NONE;
158 if ((nexthdr != IPPROTO_HOPOPTS)
159 && (nexthdr != IPPROTO_ROUTING)
160 && (nexthdr != IPPROTO_DSTOPTS)
161 && (nexthdr != IPPROTO_AH)
162 && (nexthdr != IPPROTO_FRAGMENT)) {
163 /* It's either a terminal header (e.g., TCP, UDP) or one we
164 * don't understand. In either case, we're done with the
165 * packet, so use it to fill in 'nw_proto'. */
169 /* We only verify that at least 8 bytes of the next header are
170 * available, but many of these headers are longer. Ensure that
171 * accesses within the extension header are within those first 8
172 * bytes. All extension headers are required to be at least 8
174 if (packet->size < 8) {
178 if ((nexthdr == IPPROTO_HOPOPTS)
179 || (nexthdr == IPPROTO_ROUTING)
180 || (nexthdr == IPPROTO_DSTOPTS)) {
181 /* These headers, while different, have the fields we care about
182 * in the same location and with the same interpretation. */
183 const struct ip6_ext *ext_hdr = packet->data;
184 nexthdr = ext_hdr->ip6e_nxt;
185 if (!ofpbuf_try_pull(packet, (ext_hdr->ip6e_len + 1) * 8)) {
188 } else if (nexthdr == IPPROTO_AH) {
189 /* A standard AH definition isn't available, but the fields
190 * we care about are in the same location as the generic
191 * option header--only the header length is calculated
193 const struct ip6_ext *ext_hdr = packet->data;
194 nexthdr = ext_hdr->ip6e_nxt;
195 if (!ofpbuf_try_pull(packet, (ext_hdr->ip6e_len + 2) * 4)) {
198 } else if (nexthdr == IPPROTO_FRAGMENT) {
199 const struct ip6_frag *frag_hdr = packet->data;
201 nexthdr = frag_hdr->ip6f_nxt;
202 if (!ofpbuf_try_pull(packet, sizeof *frag_hdr)) {
206 /* We only process the first fragment. */
207 if (frag_hdr->ip6f_offlg != htons(0)) {
208 if ((frag_hdr->ip6f_offlg & IP6F_OFF_MASK) == htons(0)) {
209 flow->nw_frag = FLOW_NW_FRAG_ANY;
211 flow->nw_frag |= FLOW_NW_FRAG_LATER;
212 nexthdr = IPPROTO_FRAGMENT;
219 flow->nw_proto = nexthdr;
224 parse_tcp(struct ofpbuf *packet, struct ofpbuf *b, struct flow *flow)
226 const struct tcp_header *tcp = pull_tcp(b);
228 flow->tp_src = tcp->tcp_src;
229 flow->tp_dst = tcp->tcp_dst;
230 packet->l7 = b->data;
235 parse_udp(struct ofpbuf *packet, struct ofpbuf *b, struct flow *flow)
237 const struct udp_header *udp = pull_udp(b);
239 flow->tp_src = udp->udp_src;
240 flow->tp_dst = udp->udp_dst;
241 packet->l7 = b->data;
246 parse_icmpv6(struct ofpbuf *b, struct flow *flow)
248 const struct icmp6_hdr *icmp = pull_icmpv6(b);
254 /* The ICMPv6 type and code fields use the 16-bit transport port
255 * fields, so we need to store them in 16-bit network byte order. */
256 flow->tp_src = htons(icmp->icmp6_type);
257 flow->tp_dst = htons(icmp->icmp6_code);
259 if (icmp->icmp6_code == 0 &&
260 (icmp->icmp6_type == ND_NEIGHBOR_SOLICIT ||
261 icmp->icmp6_type == ND_NEIGHBOR_ADVERT)) {
262 const struct in6_addr *nd_target;
264 nd_target = ofpbuf_try_pull(b, sizeof *nd_target);
268 flow->nd_target = *nd_target;
270 while (b->size >= 8) {
271 /* The minimum size of an option is 8 bytes, which also is
272 * the size of Ethernet link-layer options. */
273 const struct nd_opt_hdr *nd_opt = b->data;
274 int opt_len = nd_opt->nd_opt_len * 8;
276 if (!opt_len || opt_len > b->size) {
280 /* Store the link layer address if the appropriate option is
281 * provided. It is considered an error if the same link
282 * layer option is specified twice. */
283 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LINKADDR
285 if (eth_addr_is_zero(flow->arp_sha)) {
286 memcpy(flow->arp_sha, nd_opt + 1, ETH_ADDR_LEN);
290 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LINKADDR
292 if (eth_addr_is_zero(flow->arp_tha)) {
293 memcpy(flow->arp_tha, nd_opt + 1, ETH_ADDR_LEN);
299 if (!ofpbuf_try_pull(b, opt_len)) {
308 memset(&flow->nd_target, 0, sizeof(flow->nd_target));
309 memset(flow->arp_sha, 0, sizeof(flow->arp_sha));
310 memset(flow->arp_tha, 0, sizeof(flow->arp_tha));
316 /* Initializes 'flow' members from 'packet', 'skb_priority', 'tun_id', and
319 * Initializes 'packet' header pointers as follows:
321 * - packet->l2 to the start of the Ethernet header.
323 * - packet->l3 to just past the Ethernet header, or just past the
324 * vlan_header if one is present, to the first byte of the payload of the
327 * - packet->l4 to just past the IPv4 header, if one is present and has a
328 * correct length, and otherwise NULL.
330 * - packet->l7 to just past the TCP or UDP or ICMP header, if one is
331 * present and has a correct length, and otherwise NULL.
334 flow_extract(struct ofpbuf *packet, uint32_t skb_priority, ovs_be64 tun_id,
335 uint16_t ofp_in_port, struct flow *flow)
337 struct ofpbuf b = *packet;
338 struct eth_header *eth;
340 COVERAGE_INC(flow_extract);
342 memset(flow, 0, sizeof *flow);
343 flow->tun_id = tun_id;
344 flow->in_port = ofp_in_port;
345 flow->skb_priority = skb_priority;
352 if (b.size < sizeof *eth) {
358 memcpy(flow->dl_src, eth->eth_src, ETH_ADDR_LEN);
359 memcpy(flow->dl_dst, eth->eth_dst, ETH_ADDR_LEN);
361 /* dl_type, vlan_tci. */
362 ofpbuf_pull(&b, ETH_ADDR_LEN * 2);
363 if (eth->eth_type == htons(ETH_TYPE_VLAN)) {
364 parse_vlan(&b, flow);
366 flow->dl_type = parse_ethertype(&b);
370 if (flow->dl_type == htons(ETH_TYPE_IP)) {
371 const struct ip_header *nh = pull_ip(&b);
375 flow->nw_src = get_unaligned_be32(&nh->ip_src);
376 flow->nw_dst = get_unaligned_be32(&nh->ip_dst);
377 flow->nw_proto = nh->ip_proto;
379 flow->nw_tos = nh->ip_tos;
380 if (IP_IS_FRAGMENT(nh->ip_frag_off)) {
381 flow->nw_frag = FLOW_NW_FRAG_ANY;
382 if (nh->ip_frag_off & htons(IP_FRAG_OFF_MASK)) {
383 flow->nw_frag |= FLOW_NW_FRAG_LATER;
386 flow->nw_ttl = nh->ip_ttl;
388 if (!(nh->ip_frag_off & htons(IP_FRAG_OFF_MASK))) {
389 if (flow->nw_proto == IPPROTO_TCP) {
390 parse_tcp(packet, &b, flow);
391 } else if (flow->nw_proto == IPPROTO_UDP) {
392 parse_udp(packet, &b, flow);
393 } else if (flow->nw_proto == IPPROTO_ICMP) {
394 const struct icmp_header *icmp = pull_icmp(&b);
396 flow->tp_src = htons(icmp->icmp_type);
397 flow->tp_dst = htons(icmp->icmp_code);
403 } else if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
404 if (parse_ipv6(&b, flow)) {
409 if (flow->nw_proto == IPPROTO_TCP) {
410 parse_tcp(packet, &b, flow);
411 } else if (flow->nw_proto == IPPROTO_UDP) {
412 parse_udp(packet, &b, flow);
413 } else if (flow->nw_proto == IPPROTO_ICMPV6) {
414 if (parse_icmpv6(&b, flow)) {
418 } else if (flow->dl_type == htons(ETH_TYPE_ARP)) {
419 const struct arp_eth_header *arp = pull_arp(&b);
420 if (arp && arp->ar_hrd == htons(1)
421 && arp->ar_pro == htons(ETH_TYPE_IP)
422 && arp->ar_hln == ETH_ADDR_LEN
423 && arp->ar_pln == 4) {
424 /* We only match on the lower 8 bits of the opcode. */
425 if (ntohs(arp->ar_op) <= 0xff) {
426 flow->nw_proto = ntohs(arp->ar_op);
429 if ((flow->nw_proto == ARP_OP_REQUEST)
430 || (flow->nw_proto == ARP_OP_REPLY)) {
431 flow->nw_src = arp->ar_spa;
432 flow->nw_dst = arp->ar_tpa;
433 memcpy(flow->arp_sha, arp->ar_sha, ETH_ADDR_LEN);
434 memcpy(flow->arp_tha, arp->ar_tha, ETH_ADDR_LEN);
440 /* For every bit of a field that is wildcarded in 'wildcards', sets the
441 * corresponding bit in 'flow' to zero. */
443 flow_zero_wildcards(struct flow *flow, const struct flow_wildcards *wildcards)
445 uint32_t *flow_u32 = (uint32_t *) flow;
446 const uint32_t *wc_u32 = (const uint32_t *) &wildcards->masks;
449 for (i = 0; i < FLOW_U32S; i++) {
450 flow_u32[i] &= wc_u32[i];
454 /* Initializes 'fmd' with the metadata found in 'flow'. */
456 flow_get_metadata(const struct flow *flow, struct flow_metadata *fmd)
458 BUILD_ASSERT_DECL(FLOW_WC_SEQ == 17);
460 fmd->tun_id = flow->tun_id;
461 fmd->metadata = flow->metadata;
462 memcpy(fmd->regs, flow->regs, sizeof fmd->regs);
463 fmd->in_port = flow->in_port;
467 flow_to_string(const struct flow *flow)
469 struct ds ds = DS_EMPTY_INITIALIZER;
470 flow_format(&ds, flow);
475 flow_format(struct ds *ds, const struct flow *flow)
477 ds_put_format(ds, "priority:%"PRIu32
480 ",in_port:%04"PRIx16,
482 ntohll(flow->tun_id),
483 ntohll(flow->metadata),
486 ds_put_format(ds, ",tci(");
487 if (flow->vlan_tci) {
488 ds_put_format(ds, "vlan:%"PRIu16",pcp:%d",
489 vlan_tci_to_vid(flow->vlan_tci),
490 vlan_tci_to_pcp(flow->vlan_tci));
492 ds_put_char(ds, '0');
494 ds_put_format(ds, ") mac("ETH_ADDR_FMT"->"ETH_ADDR_FMT
496 ETH_ADDR_ARGS(flow->dl_src),
497 ETH_ADDR_ARGS(flow->dl_dst),
498 ntohs(flow->dl_type));
500 if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
501 ds_put_format(ds, " label:%#"PRIx32" proto:%"PRIu8" tos:%#"PRIx8
502 " ttl:%"PRIu8" ipv6(",
503 ntohl(flow->ipv6_label), flow->nw_proto,
504 flow->nw_tos, flow->nw_ttl);
505 print_ipv6_addr(ds, &flow->ipv6_src);
506 ds_put_cstr(ds, "->");
507 print_ipv6_addr(ds, &flow->ipv6_dst);
508 ds_put_char(ds, ')');
510 ds_put_format(ds, " proto:%"PRIu8" tos:%#"PRIx8" ttl:%"PRIu8
511 " ip("IP_FMT"->"IP_FMT")",
512 flow->nw_proto, flow->nw_tos, flow->nw_ttl,
513 IP_ARGS(&flow->nw_src), IP_ARGS(&flow->nw_dst));
516 ds_put_format(ds, " frag(%s)",
517 flow->nw_frag == FLOW_NW_FRAG_ANY ? "first"
518 : flow->nw_frag == (FLOW_NW_FRAG_ANY | FLOW_NW_FRAG_LATER)
519 ? "later" : "<error>");
521 if (flow->tp_src || flow->tp_dst) {
522 ds_put_format(ds, " port(%"PRIu16"->%"PRIu16")",
523 ntohs(flow->tp_src), ntohs(flow->tp_dst));
525 if (!eth_addr_is_zero(flow->arp_sha) || !eth_addr_is_zero(flow->arp_tha)) {
526 ds_put_format(ds, " arp_ha("ETH_ADDR_FMT"->"ETH_ADDR_FMT")",
527 ETH_ADDR_ARGS(flow->arp_sha),
528 ETH_ADDR_ARGS(flow->arp_tha));
533 flow_print(FILE *stream, const struct flow *flow)
535 char *s = flow_to_string(flow);
540 /* flow_wildcards functions. */
542 /* Initializes 'wc' as a set of wildcards that matches every packet. */
544 flow_wildcards_init_catchall(struct flow_wildcards *wc)
546 memset(&wc->masks, 0, sizeof wc->masks);
549 /* Initializes 'wc' as an exact-match set of wildcards; that is, 'wc' does not
550 * wildcard any bits or fields. */
552 flow_wildcards_init_exact(struct flow_wildcards *wc)
554 memset(&wc->masks, 0xff, sizeof wc->masks);
555 memset(wc->masks.zeros, 0, sizeof wc->masks.zeros);
558 /* Returns true if 'wc' matches every packet, false if 'wc' fixes any bits or
561 flow_wildcards_is_catchall(const struct flow_wildcards *wc)
563 const uint32_t *wc_u32 = (const uint32_t *) &wc->masks;
566 for (i = 0; i < FLOW_U32S; i++) {
574 /* Initializes 'dst' as the combination of wildcards in 'src1' and 'src2'.
575 * That is, a bit or a field is wildcarded in 'dst' if it is wildcarded in
576 * 'src1' or 'src2' or both. */
578 flow_wildcards_combine(struct flow_wildcards *dst,
579 const struct flow_wildcards *src1,
580 const struct flow_wildcards *src2)
582 uint32_t *dst_u32 = (uint32_t *) &dst->masks;
583 const uint32_t *src1_u32 = (const uint32_t *) &src1->masks;
584 const uint32_t *src2_u32 = (const uint32_t *) &src2->masks;
587 for (i = 0; i < FLOW_U32S; i++) {
588 dst_u32[i] = src1_u32[i] & src2_u32[i];
592 /* Returns a hash of the wildcards in 'wc'. */
594 flow_wildcards_hash(const struct flow_wildcards *wc, uint32_t basis)
596 return flow_hash(&wc->masks, basis);;
599 /* Returns true if 'a' and 'b' represent the same wildcards, false if they are
602 flow_wildcards_equal(const struct flow_wildcards *a,
603 const struct flow_wildcards *b)
605 return flow_equal(&a->masks, &b->masks);
608 /* Returns true if at least one bit or field is wildcarded in 'a' but not in
609 * 'b', false otherwise. */
611 flow_wildcards_has_extra(const struct flow_wildcards *a,
612 const struct flow_wildcards *b)
614 const uint32_t *a_u32 = (const uint32_t *) &a->masks;
615 const uint32_t *b_u32 = (const uint32_t *) &b->masks;
618 for (i = 0; i < FLOW_U32S; i++) {
619 if ((a_u32[i] & b_u32[i]) != b_u32[i]) {
626 /* Returns true if 'a' and 'b' are equal, except that 0-bits (wildcarded bits)
627 * in 'wc' do not need to be equal in 'a' and 'b'. */
629 flow_equal_except(const struct flow *a, const struct flow *b,
630 const struct flow_wildcards *wc)
632 const uint32_t *a_u32 = (const uint32_t *) a;
633 const uint32_t *b_u32 = (const uint32_t *) b;
634 const uint32_t *wc_u32 = (const uint32_t *) &wc->masks;
637 for (i = 0; i < FLOW_U32S; i++) {
638 if ((a_u32[i] ^ b_u32[i]) & wc_u32[i]) {
645 /* Sets the wildcard mask for register 'idx' in 'wc' to 'mask'.
646 * (A 0-bit indicates a wildcard bit.) */
648 flow_wildcards_set_reg_mask(struct flow_wildcards *wc, int idx, uint32_t mask)
650 wc->masks.regs[idx] = mask;
653 /* Hashes 'flow' based on its L2 through L4 protocol information. */
655 flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis)
660 struct in6_addr ipv6_addr;
665 uint8_t eth_addr[ETH_ADDR_LEN];
671 memset(&fields, 0, sizeof fields);
672 for (i = 0; i < ETH_ADDR_LEN; i++) {
673 fields.eth_addr[i] = flow->dl_src[i] ^ flow->dl_dst[i];
675 fields.vlan_tci = flow->vlan_tci & htons(VLAN_VID_MASK);
676 fields.eth_type = flow->dl_type;
678 /* UDP source and destination port are not taken into account because they
679 * will not necessarily be symmetric in a bidirectional flow. */
680 if (fields.eth_type == htons(ETH_TYPE_IP)) {
681 fields.ipv4_addr = flow->nw_src ^ flow->nw_dst;
682 fields.ip_proto = flow->nw_proto;
683 if (fields.ip_proto == IPPROTO_TCP) {
684 fields.tp_port = flow->tp_src ^ flow->tp_dst;
686 } else if (fields.eth_type == htons(ETH_TYPE_IPV6)) {
687 const uint8_t *a = &flow->ipv6_src.s6_addr[0];
688 const uint8_t *b = &flow->ipv6_dst.s6_addr[0];
689 uint8_t *ipv6_addr = &fields.ipv6_addr.s6_addr[0];
691 for (i=0; i<16; i++) {
692 ipv6_addr[i] = a[i] ^ b[i];
694 fields.ip_proto = flow->nw_proto;
695 if (fields.ip_proto == IPPROTO_TCP) {
696 fields.tp_port = flow->tp_src ^ flow->tp_dst;
699 return hash_bytes(&fields, sizeof fields, basis);
702 /* Hashes the portions of 'flow' designated by 'fields'. */
704 flow_hash_fields(const struct flow *flow, enum nx_hash_fields fields,
709 case NX_HASH_FIELDS_ETH_SRC:
710 return hash_bytes(flow->dl_src, sizeof flow->dl_src, basis);
712 case NX_HASH_FIELDS_SYMMETRIC_L4:
713 return flow_hash_symmetric_l4(flow, basis);
719 /* Returns a string representation of 'fields'. */
721 flow_hash_fields_to_str(enum nx_hash_fields fields)
724 case NX_HASH_FIELDS_ETH_SRC: return "eth_src";
725 case NX_HASH_FIELDS_SYMMETRIC_L4: return "symmetric_l4";
726 default: return "<unknown>";
730 /* Returns true if the value of 'fields' is supported. Otherwise false. */
732 flow_hash_fields_valid(enum nx_hash_fields fields)
734 return fields == NX_HASH_FIELDS_ETH_SRC
735 || fields == NX_HASH_FIELDS_SYMMETRIC_L4;
738 /* Sets the VLAN VID that 'flow' matches to 'vid', which is interpreted as an
739 * OpenFlow 1.0 "dl_vlan" value:
741 * - If it is in the range 0...4095, 'flow->vlan_tci' is set to match
742 * that VLAN. Any existing PCP match is unchanged (it becomes 0 if
743 * 'flow' previously matched packets without a VLAN header).
745 * - If it is OFP_VLAN_NONE, 'flow->vlan_tci' is set to match a packet
746 * without a VLAN tag.
748 * - Other values of 'vid' should not be used. */
750 flow_set_dl_vlan(struct flow *flow, ovs_be16 vid)
752 if (vid == htons(OFP10_VLAN_NONE)) {
753 flow->vlan_tci = htons(0);
755 vid &= htons(VLAN_VID_MASK);
756 flow->vlan_tci &= ~htons(VLAN_VID_MASK);
757 flow->vlan_tci |= htons(VLAN_CFI) | vid;
761 /* Sets the VLAN VID that 'flow' matches to 'vid', which is interpreted as an
762 * OpenFlow 1.2 "vlan_vid" value, that is, the low 13 bits of 'vlan_tci' (VID
765 flow_set_vlan_vid(struct flow *flow, ovs_be16 vid)
767 ovs_be16 mask = htons(VLAN_VID_MASK | VLAN_CFI);
768 flow->vlan_tci &= ~mask;
769 flow->vlan_tci |= vid & mask;
772 /* Sets the VLAN PCP that 'flow' matches to 'pcp', which should be in the
775 * This function has no effect on the VLAN ID that 'flow' matches.
777 * After calling this function, 'flow' will not match packets without a VLAN
780 flow_set_vlan_pcp(struct flow *flow, uint8_t pcp)
783 flow->vlan_tci &= ~htons(VLAN_PCP_MASK);
784 flow->vlan_tci |= htons((pcp << VLAN_PCP_SHIFT) | VLAN_CFI);
787 /* Puts into 'b' a packet that flow_extract() would parse as having the given
790 * (This is useful only for testing, obviously, and the packet isn't really
791 * valid. It hasn't got some checksums filled in, for one, and lots of fields
792 * are just zeroed.) */
794 flow_compose(struct ofpbuf *b, const struct flow *flow)
796 eth_compose(b, flow->dl_dst, flow->dl_src, ntohs(flow->dl_type), 0);
797 if (flow->dl_type == htons(FLOW_DL_TYPE_NONE)) {
798 struct eth_header *eth = b->l2;
799 eth->eth_type = htons(b->size);
803 if (flow->vlan_tci & htons(VLAN_CFI)) {
804 eth_push_vlan(b, flow->vlan_tci);
807 if (flow->dl_type == htons(ETH_TYPE_IP)) {
808 struct ip_header *ip;
810 b->l3 = ip = ofpbuf_put_zeros(b, sizeof *ip);
811 ip->ip_ihl_ver = IP_IHL_VER(5, 4);
812 ip->ip_tos = flow->nw_tos;
813 ip->ip_proto = flow->nw_proto;
814 ip->ip_src = flow->nw_src;
815 ip->ip_dst = flow->nw_dst;
817 if (flow->nw_frag & FLOW_NW_FRAG_ANY) {
818 ip->ip_frag_off |= htons(IP_MORE_FRAGMENTS);
819 if (flow->nw_frag & FLOW_NW_FRAG_LATER) {
820 ip->ip_frag_off |= htons(100);
823 if (!(flow->nw_frag & FLOW_NW_FRAG_ANY)
824 || !(flow->nw_frag & FLOW_NW_FRAG_LATER)) {
825 if (flow->nw_proto == IPPROTO_TCP) {
826 struct tcp_header *tcp;
828 b->l4 = tcp = ofpbuf_put_zeros(b, sizeof *tcp);
829 tcp->tcp_src = flow->tp_src;
830 tcp->tcp_dst = flow->tp_dst;
831 tcp->tcp_ctl = TCP_CTL(0, 5);
832 } else if (flow->nw_proto == IPPROTO_UDP) {
833 struct udp_header *udp;
835 b->l4 = udp = ofpbuf_put_zeros(b, sizeof *udp);
836 udp->udp_src = flow->tp_src;
837 udp->udp_dst = flow->tp_dst;
838 } else if (flow->nw_proto == IPPROTO_ICMP) {
839 struct icmp_header *icmp;
841 b->l4 = icmp = ofpbuf_put_zeros(b, sizeof *icmp);
842 icmp->icmp_type = ntohs(flow->tp_src);
843 icmp->icmp_code = ntohs(flow->tp_dst);
844 icmp->icmp_csum = csum(icmp, ICMP_HEADER_LEN);
849 ip->ip_tot_len = htons((uint8_t *) b->data + b->size
850 - (uint8_t *) b->l3);
851 ip->ip_csum = csum(ip, sizeof *ip);
852 } else if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
854 } else if (flow->dl_type == htons(ETH_TYPE_ARP)) {
855 struct arp_eth_header *arp;
857 b->l3 = arp = ofpbuf_put_zeros(b, sizeof *arp);
858 arp->ar_hrd = htons(1);
859 arp->ar_pro = htons(ETH_TYPE_IP);
860 arp->ar_hln = ETH_ADDR_LEN;
862 arp->ar_op = htons(flow->nw_proto);
864 if (flow->nw_proto == ARP_OP_REQUEST ||
865 flow->nw_proto == ARP_OP_REPLY) {
866 arp->ar_spa = flow->nw_src;
867 arp->ar_tpa = flow->nw_dst;
868 memcpy(arp->ar_sha, flow->arp_sha, ETH_ADDR_LEN);
869 memcpy(arp->ar_tha, flow->arp_tha, ETH_ADDR_LEN);