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
23 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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35 #include "learning-switch.h"
39 #include <netinet/in.h>
45 #include "mac-learning.h"
46 #include "ofp-print.h"
53 #define THIS_MODULE VLM_learning_switch
57 /* If nonnegative, the switch sets up flows that expire after the given
58 * number of seconds (or never expire, if the value is OFP_FLOW_PERMANENT).
59 * Otherwise, the switch processes every packet. */
63 time_t last_features_request;
64 struct mac_learning *ml; /* NULL to act as hub instead of switch. */
67 static void queue_tx(struct lswitch *, struct rconn *, struct buffer *);
68 static void send_features_request(struct lswitch *, struct rconn *);
69 static void process_packet_in(struct lswitch *, struct rconn *,
70 struct ofp_packet_in *);
71 static void process_echo_request(struct lswitch *, struct rconn *,
74 /* Creates and returns a new learning switch.
76 * If 'learn_macs' is true, the new switch will learn the ports on which MAC
77 * addresses appear. Otherwise, the new switch will flood all packets.
79 * If 'max_idle' is nonnegative, the new switch will set up flows that expire
80 * after the given number of seconds (or never expire, if 'max_idle' is
81 * OFP_FLOW_PERMANENT). Otherwise, the new switch will process every packet.
83 * 'rconn' is used to send out an OpenFlow features request. */
85 lswitch_create(struct rconn *rconn, bool learn_macs, int max_idle)
87 struct lswitch *sw = xmalloc(sizeof *sw);
88 memset(sw, 0, sizeof *sw);
89 sw->max_idle = max_idle;
91 sw->last_features_request = time(0) - 1;
92 sw->ml = learn_macs ? mac_learning_create() : NULL;
93 send_features_request(sw, rconn);
99 lswitch_destroy(struct lswitch *sw)
102 mac_learning_destroy(sw->ml);
107 /* Processes 'msg', which should be an OpenFlow received on 'rconn', according
108 * to the learning switch state in 'sw'. The most likely result of processing
109 * is that flow-setup and packet-out OpenFlow messages will be sent out on
112 lswitch_process_packet(struct lswitch *sw, struct rconn *rconn,
113 const struct buffer *msg)
115 static const size_t min_size[UINT8_MAX + 1] = {
116 [0 ... UINT8_MAX] = sizeof (struct ofp_header),
117 [OFPT_FEATURES_REPLY] = sizeof (struct ofp_switch_features),
118 [OFPT_PACKET_IN] = offsetof (struct ofp_packet_in, data),
120 struct ofp_header *oh;
123 if (msg->size < min_size[oh->type]) {
124 VLOG_WARN("%s: too short (%zu bytes) for type %"PRIu8" (min %zu)",
125 rconn_get_name(rconn),
126 msg->size, oh->type, min_size[oh->type]);
130 if (oh->type == OFPT_ECHO_REQUEST) {
131 process_echo_request(sw, rconn, msg->data);
132 } else if (oh->type == OFPT_FEATURES_REPLY) {
133 struct ofp_switch_features *osf = msg->data;
134 sw->datapath_id = osf->datapath_id;
135 } else if (sw->datapath_id == 0) {
136 send_features_request(sw, rconn);
137 } else if (oh->type == OFPT_PACKET_IN) {
138 process_packet_in(sw, rconn, msg->data);
140 if (VLOG_IS_DBG_ENABLED()) {
141 char *p = ofp_to_string(msg->data, msg->size, 2);
142 VLOG_DBG("OpenFlow packet ignored: %s", p);
149 send_features_request(struct lswitch *sw, struct rconn *rconn)
151 time_t now = time(0);
152 if (now >= sw->last_features_request + 1) {
154 struct ofp_header *ofr;
155 struct ofp_switch_config *osc;
157 /* Send OFPT_FEATURES_REQUEST. */
159 ofr = buffer_put_uninit(b, sizeof *ofr);
160 memset(ofr, 0, sizeof *ofr);
161 ofr->type = OFPT_FEATURES_REQUEST;
162 ofr->version = OFP_VERSION;
163 ofr->length = htons(sizeof *ofr);
164 queue_tx(sw, rconn, b);
166 /* Send OFPT_SET_CONFIG. */
168 osc = buffer_put_uninit(b, sizeof *osc);
169 memset(osc, 0, sizeof *osc);
170 osc->header.type = OFPT_SET_CONFIG;
171 osc->header.version = OFP_VERSION;
172 osc->header.length = htons(sizeof *osc);
173 osc->flags = htons(OFPC_SEND_FLOW_EXP);
174 osc->miss_send_len = htons(OFP_DEFAULT_MISS_SEND_LEN);
175 queue_tx(sw, rconn, b);
177 sw->last_features_request = now;
182 queue_tx(struct lswitch *sw, struct rconn *rconn, struct buffer *b)
184 int retval = rconn_send(rconn, b);
186 if (retval == EAGAIN) {
187 /* FIXME: ratelimit. */
188 VLOG_WARN("%s: tx queue overflow", rconn_get_name(rconn));
189 } else if (retval == ENOTCONN) {
192 /* FIXME: ratelimit. */
193 VLOG_WARN("%s: send: %s", rconn_get_name(rconn), strerror(retval));
200 process_packet_in(struct lswitch *sw, struct rconn *rconn,
201 struct ofp_packet_in *opi)
203 uint16_t in_port = ntohs(opi->in_port);
204 uint16_t out_port = OFPP_FLOOD;
206 size_t pkt_ofs, pkt_len;
210 /* Extract flow data from 'opi' into 'flow'. */
211 pkt_ofs = offsetof(struct ofp_packet_in, data);
212 pkt_len = ntohs(opi->header.length) - pkt_ofs;
213 pkt.data = opi->data;
215 flow_extract(&pkt, in_port, &flow);
218 if (mac_learning_learn(sw->ml, flow.dl_src, in_port)) {
219 VLOG_DBG("learned that "ETH_ADDR_FMT" is on datapath %"
220 PRIx64" port %"PRIu16, ETH_ADDR_ARGS(flow.dl_src),
221 ntohll(sw->datapath_id), in_port);
223 out_port = mac_learning_lookup(sw->ml, flow.dl_dst);
226 if (in_port == out_port) {
227 /* The input port and output port match, so just drop the packet
230 } else if (sw->max_idle >= 0 && (!sw->ml || out_port != OFPP_FLOOD)) {
231 /* The output port is known, or we always flood everything, so add a
233 queue_tx(sw, rconn, make_add_simple_flow(&flow, ntohl(opi->buffer_id),
234 out_port, sw->max_idle));
236 /* If the switch didn't buffer the packet, we need to send a copy. */
237 if (ntohl(opi->buffer_id) == UINT32_MAX) {
239 make_unbuffered_packet_out(&pkt, in_port, out_port));
242 /* We don't know that MAC, or we don't set up flows. Send along the
243 * packet without setting up a flow. */
245 if (ntohl(opi->buffer_id) == UINT32_MAX) {
246 b = make_unbuffered_packet_out(&pkt, in_port, out_port);
248 b = make_buffered_packet_out(ntohl(opi->buffer_id),
251 queue_tx(sw, rconn, b);
256 process_echo_request(struct lswitch *sw, struct rconn *rconn,
257 struct ofp_header *rq)
259 queue_tx(sw, rconn, make_echo_reply(rq));