1 /* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
4 * We are making the OpenFlow specification and associated documentation
5 * (Software) available for public use and benefit with the expectation
6 * that others will use, modify and enhance the Software and contribute
7 * those enhancements back to the community. However, since we would
8 * like to make the Software available for broadest use, with as few
9 * restrictions as possible permission is hereby granted, free of
10 * charge, to any person obtaining a copy of this Software to deal in
11 * the Software under the copyrights without restriction, including
12 * without limitation the rights to use, copy, modify, merge, publish,
13 * distribute, sublicense, and/or sell copies of the Software, and to
14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
25 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
26 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
29 * The name and trademarks of copyright holder(s) may NOT be used in
30 * advertising or publicity pertaining to the Software or any
31 * derivatives without specific, written prior permission.
34 #include <sys/types.h>
37 #include <netinet/in.h>
45 #define THIS_MODULE VLM_flow
48 pull_ip(struct buffer *packet)
50 if (packet->size >= IP_HEADER_LEN) {
51 struct ip_header *ip = packet->data;
52 int ip_len = IP_IHL(ip->ip_ihl_ver) * 4;
53 if (ip_len >= IP_HEADER_LEN && packet->size >= ip_len) {
54 return buffer_pull(packet, ip_len);
61 pull_tcp(struct buffer *packet)
63 if (packet->size >= TCP_HEADER_LEN) {
64 struct tcp_header *tcp = packet->data;
65 int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
66 if (tcp_len >= TCP_HEADER_LEN && packet->size >= tcp_len) {
67 return buffer_pull(packet, tcp_len);
74 pull_udp(struct buffer *packet)
76 return buffer_try_pull(packet, UDP_HEADER_LEN);
80 pull_eth(struct buffer *packet)
82 return buffer_try_pull(packet, ETH_HEADER_LEN);
86 flow_extract(struct buffer *packet, uint16_t in_port, struct flow *flow)
88 struct buffer b = *packet;
89 struct eth_header *eth;
91 if (b.size < ETH_TOTAL_MIN) {
92 /* This message is not too useful since there are various ways that we
93 * can end up with runt frames, e.g. frames that only ever passed
94 * through virtual network devices and never touched a physical
96 VLOG_DBG("packet length %zu less than minimum size %d",
97 b.size, ETH_TOTAL_MIN);
100 memset(flow, 0, sizeof *flow);
101 flow->in_port = htons(in_port);
110 if (ntohs(eth->eth_type) >= OFP_DL_TYPE_ETH2_CUTOFF) {
111 /* This is an Ethernet II frame */
112 flow->dl_type = eth->eth_type;
114 /* This is an 802.2 frame */
115 struct llc_snap_header *h = buffer_at(&b, 0, sizeof *h);
119 if (h->llc.llc_dsap == LLC_DSAP_SNAP
120 && h->llc.llc_ssap == LLC_SSAP_SNAP
121 && h->llc.llc_cntl == LLC_CNTL_SNAP
122 && !memcmp(h->snap.snap_org, SNAP_ORG_ETHERNET,
123 sizeof h->snap.snap_org)) {
124 flow->dl_type = h->snap.snap_type;
125 buffer_pull(&b, sizeof *h);
127 flow->dl_type = OFP_DL_TYPE_NOT_ETH_TYPE;
128 buffer_pull(&b, sizeof(struct llc_header));
132 /* Check for a VLAN tag */
133 if (flow->dl_type != htons(ETH_TYPE_VLAN)) {
134 flow->dl_vlan = htons(OFP_VLAN_NONE);
136 struct vlan_header *vh = buffer_at(&b, 0, sizeof *vh);
137 flow->dl_type = vh->vlan_next_type;
138 flow->dl_vlan = vh->vlan_tci & htons(VLAN_VID);
139 buffer_pull(&b, sizeof *vh);
141 memcpy(flow->dl_src, eth->eth_src, ETH_ADDR_LEN);
142 memcpy(flow->dl_dst, eth->eth_dst, ETH_ADDR_LEN);
145 if (flow->dl_type == htons(ETH_TYPE_IP)) {
146 const struct ip_header *nh = pull_ip(&b);
148 flow->nw_src = nh->ip_src;
149 flow->nw_dst = nh->ip_dst;
150 flow->nw_proto = nh->ip_proto;
152 if (flow->nw_proto == IP_TYPE_TCP) {
153 const struct tcp_header *tcp = pull_tcp(&b);
155 flow->tp_src = tcp->tcp_src;
156 flow->tp_dst = tcp->tcp_dst;
159 /* Avoid tricking other code into thinking that this
160 * packet has an L4 header. */
163 } else if (flow->nw_proto == IP_TYPE_UDP) {
164 const struct udp_header *udp = pull_udp(&b);
166 flow->tp_src = udp->udp_src;
167 flow->tp_dst = udp->udp_dst;
170 /* Avoid tricking other code into thinking that this
171 * packet has an L4 header. */
181 flow_print(FILE *stream, const struct flow *flow)
184 "port%04x:vlan%04x mac"ETH_ADDR_FMT"->"ETH_ADDR_FMT" "
185 "proto%04x ip"IP_FMT"->"IP_FMT" port%d->%d",
186 ntohs(flow->in_port), ntohs(flow->dl_vlan),
187 ETH_ADDR_ARGS(flow->dl_src), ETH_ADDR_ARGS(flow->dl_dst),
188 ntohs(flow->dl_type),
189 IP_ARGS(&flow->nw_src), IP_ARGS(&flow->nw_dst),
190 ntohs(flow->tp_src), ntohs(flow->tp_dst));
194 flow_compare(const struct flow *a, const struct flow *b)
196 return memcmp(a, b, sizeof *a);
200 flow_hash(const struct flow *flow, uint32_t basis)
202 return hash_fnv(flow, sizeof *flow, basis);