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
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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
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24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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29 * The name and trademarks of copyright holder(s) may NOT be used in
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35 #include "learning-switch.h"
39 #include <netinet/in.h>
45 #include "mac-learning.h"
46 #include "ofp-print.h"
54 #define THIS_MODULE VLM_learning_switch
58 /* If nonnegative, the switch sets up flows that expire after the given
59 * number of seconds (or never expire, if the value is OFP_FLOW_PERMANENT).
60 * Otherwise, the switch processes every packet. */
64 time_t last_features_request;
65 struct mac_learning *ml; /* NULL to act as hub instead of switch. */
67 /* Number of outgoing queued packets on the rconn. */
71 /* The log messages here could actually be useful in debugging, so keep the
72 * rate limit relatively high. */
73 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(30, 300);
75 static void queue_tx(struct lswitch *, struct rconn *, struct buffer *);
76 static void send_features_request(struct lswitch *, struct rconn *);
77 static void process_packet_in(struct lswitch *, struct rconn *,
78 struct ofp_packet_in *);
79 static void process_echo_request(struct lswitch *, struct rconn *,
82 /* Creates and returns a new learning switch.
84 * If 'learn_macs' is true, the new switch will learn the ports on which MAC
85 * addresses appear. Otherwise, the new switch will flood all packets.
87 * If 'max_idle' is nonnegative, the new switch will set up flows that expire
88 * after the given number of seconds (or never expire, if 'max_idle' is
89 * OFP_FLOW_PERMANENT). Otherwise, the new switch will process every packet.
91 * 'rconn' is used to send out an OpenFlow features request. */
93 lswitch_create(struct rconn *rconn, bool learn_macs, int max_idle)
95 struct lswitch *sw = xcalloc(1, sizeof *sw);
96 sw->max_idle = max_idle;
98 sw->last_features_request = time_now() - 1;
99 sw->ml = learn_macs ? mac_learning_create() : NULL;
100 send_features_request(sw, rconn);
106 lswitch_destroy(struct lswitch *sw)
109 mac_learning_destroy(sw->ml);
114 /* Processes 'msg', which should be an OpenFlow received on 'rconn', according
115 * to the learning switch state in 'sw'. The most likely result of processing
116 * is that flow-setup and packet-out OpenFlow messages will be sent out on
119 lswitch_process_packet(struct lswitch *sw, struct rconn *rconn,
120 const struct buffer *msg)
122 static const size_t min_size[UINT8_MAX + 1] = {
123 [0 ... UINT8_MAX] = sizeof (struct ofp_header),
124 [OFPT_FEATURES_REPLY] = sizeof (struct ofp_switch_features),
125 [OFPT_PACKET_IN] = offsetof (struct ofp_packet_in, data),
127 struct ofp_header *oh;
130 if (msg->size < min_size[oh->type]) {
132 "%s: too short (%zu bytes) for type %"PRIu8" (min %zu)",
133 rconn_get_name(rconn),
134 msg->size, oh->type, min_size[oh->type]);
138 if (oh->type == OFPT_ECHO_REQUEST) {
139 process_echo_request(sw, rconn, msg->data);
140 } else if (oh->type == OFPT_FEATURES_REPLY) {
141 struct ofp_switch_features *osf = msg->data;
142 sw->datapath_id = osf->datapath_id;
143 } else if (sw->datapath_id == 0) {
144 send_features_request(sw, rconn);
145 } else if (oh->type == OFPT_PACKET_IN) {
146 process_packet_in(sw, rconn, msg->data);
148 if (VLOG_IS_DBG_ENABLED()) {
149 char *p = ofp_to_string(msg->data, msg->size, 2);
150 VLOG_DBG_RL(&rl, "OpenFlow packet ignored: %s", p);
157 send_features_request(struct lswitch *sw, struct rconn *rconn)
159 time_t now = time_now();
160 if (now >= sw->last_features_request + 1) {
162 struct ofp_header *ofr;
163 struct ofp_switch_config *osc;
165 /* Send OFPT_FEATURES_REQUEST. */
167 ofr = buffer_put_uninit(b, sizeof *ofr);
168 memset(ofr, 0, sizeof *ofr);
169 ofr->type = OFPT_FEATURES_REQUEST;
170 ofr->version = OFP_VERSION;
171 ofr->length = htons(sizeof *ofr);
172 queue_tx(sw, rconn, b);
174 /* Send OFPT_SET_CONFIG. */
176 osc = buffer_put_uninit(b, sizeof *osc);
177 memset(osc, 0, sizeof *osc);
178 osc->header.type = OFPT_SET_CONFIG;
179 osc->header.version = OFP_VERSION;
180 osc->header.length = htons(sizeof *osc);
181 osc->flags = htons(OFPC_SEND_FLOW_EXP);
182 osc->miss_send_len = htons(OFP_DEFAULT_MISS_SEND_LEN);
183 queue_tx(sw, rconn, b);
185 sw->last_features_request = now;
190 queue_tx(struct lswitch *sw, struct rconn *rconn, struct buffer *b)
192 int retval = rconn_send_with_limit(rconn, b, &sw->n_queued, 10);
193 if (retval && retval != ENOTCONN) {
194 if (retval == EAGAIN) {
195 VLOG_WARN_RL(&rl, "%s: tx queue overflow", rconn_get_name(rconn));
197 VLOG_WARN_RL(&rl, "%s: send: %s",
198 rconn_get_name(rconn), strerror(retval));
204 process_packet_in(struct lswitch *sw, struct rconn *rconn,
205 struct ofp_packet_in *opi)
207 uint16_t in_port = ntohs(opi->in_port);
208 uint16_t out_port = OFPP_FLOOD;
210 size_t pkt_ofs, pkt_len;
214 /* Extract flow data from 'opi' into 'flow'. */
215 pkt_ofs = offsetof(struct ofp_packet_in, data);
216 pkt_len = ntohs(opi->header.length) - pkt_ofs;
217 pkt.data = opi->data;
219 flow_extract(&pkt, in_port, &flow);
222 if (mac_learning_learn(sw->ml, flow.dl_src, in_port)) {
223 VLOG_DBG_RL(&rl, "learned that "ETH_ADDR_FMT" is on datapath %"
224 PRIx64" port %"PRIu16, ETH_ADDR_ARGS(flow.dl_src),
225 ntohll(sw->datapath_id), in_port);
227 out_port = mac_learning_lookup(sw->ml, flow.dl_dst);
230 if (in_port == out_port) {
231 /* The input and output port match. Set up a flow to drop packets. */
232 queue_tx(sw, rconn, make_add_flow(&flow, ntohl(opi->buffer_id),
234 } else if (sw->max_idle >= 0 && (!sw->ml || out_port != OFPP_FLOOD)) {
235 /* The output port is known, or we always flood everything, so add a
237 queue_tx(sw, rconn, make_add_simple_flow(&flow, ntohl(opi->buffer_id),
238 out_port, sw->max_idle));
240 /* If the switch didn't buffer the packet, we need to send a copy. */
241 if (ntohl(opi->buffer_id) == UINT32_MAX) {
243 make_unbuffered_packet_out(&pkt, in_port, out_port));
246 /* We don't know that MAC, or we don't set up flows. Send along the
247 * packet without setting up a flow. */
249 if (ntohl(opi->buffer_id) == UINT32_MAX) {
250 b = make_unbuffered_packet_out(&pkt, in_port, out_port);
252 b = make_buffered_packet_out(ntohl(opi->buffer_id),
255 queue_tx(sw, rconn, b);
260 process_echo_request(struct lswitch *sw, struct rconn *rconn,
261 struct ofp_header *rq)
263 queue_tx(sw, rconn, make_echo_reply(rq));