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.
40 #include <netinet/in.h>
45 #include "netlink-protocol.h"
47 #include "openflow/openflow-netlink.h"
48 #include "openflow/openflow.h"
54 #define THIS_MODULE VLM_dpif
56 /* Not really much point in logging many dpif errors. */
57 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 60);
59 /* The Generic Netlink family number used for OpenFlow. */
60 static int openflow_family;
62 static int lookup_openflow_multicast_group(int dp_idx, int *multicast_group);
63 static int send_mgmt_command(struct dpif *, int command,
66 /* Opens the local datapath numbered 'dp_idx', initializing 'dp'. If
67 * 'subscribe' is true, listens for asynchronous messages (packet-in, etc.)
68 * from the datapath; otherwise, 'dp' will receive only replies to explicitly
69 * initiated requests. */
71 dpif_open(int dp_idx, bool subscribe, struct dpif *dp)
74 int multicast_group = 0;
77 retval = nl_lookup_genl_family(DP_GENL_FAMILY_NAME, &openflow_family);
83 retval = lookup_openflow_multicast_group(dp_idx, &multicast_group);
89 /* Specify a large so_rcvbuf size because we occasionally need to be able
90 * to retrieve large collections of flow records. */
91 retval = nl_sock_create(NETLINK_GENERIC, multicast_group, 0,
92 4 * 1024u * 1024, &sock);
104 dpif_close(struct dpif *dp)
107 nl_sock_destroy(dp->sock);
111 static const struct nl_policy openflow_policy[] = {
112 [DP_GENL_A_DP_IDX] = { .type = NL_A_U32 },
113 [DP_GENL_A_OPENFLOW] = { .type = NL_A_UNSPEC,
114 .min_len = sizeof(struct ofp_header),
118 /* Tries to receive an openflow message from the kernel on 'sock'. If
119 * successful, stores the received message into '*msgp' and returns 0. The
120 * caller is responsible for destroying the message with ofpbuf_delete(). On
121 * failure, returns a positive errno value and stores a null pointer into
124 * Only Netlink messages with embedded OpenFlow messages are accepted. Other
125 * Netlink messages provoke errors.
127 * If 'wait' is true, dpif_recv_openflow waits for a message to be ready;
128 * otherwise, returns EAGAIN if the 'sock' receive buffer is empty. */
130 dpif_recv_openflow(struct dpif *dp, struct ofpbuf **bufferp,
133 struct nlattr *attrs[ARRAY_SIZE(openflow_policy)];
134 struct ofpbuf *buffer;
135 struct ofp_header *oh;
139 buffer = *bufferp = NULL;
141 ofpbuf_delete(buffer);
142 retval = nl_sock_recv(dp->sock, &buffer, wait);
143 } while (retval == ENOBUFS
145 && (nl_msg_nlmsgerr(buffer, NULL)
146 || nl_msg_nlmsghdr(buffer)->nlmsg_type == NLMSG_DONE)));
148 if (retval != EAGAIN) {
149 VLOG_WARN_RL(&rl, "dpif_recv_openflow: %s", strerror(retval));
154 if (nl_msg_genlmsghdr(buffer) == NULL) {
155 VLOG_DBG_RL(&rl, "received packet too short for Generic Netlink");
158 if (nl_msg_nlmsghdr(buffer)->nlmsg_type != openflow_family) {
159 VLOG_DBG_RL(&rl, "received type (%"PRIu16") != openflow family (%d)",
160 nl_msg_nlmsghdr(buffer)->nlmsg_type, openflow_family);
164 if (!nl_policy_parse(buffer, openflow_policy, attrs,
165 ARRAY_SIZE(openflow_policy))) {
168 if (nl_attr_get_u32(attrs[DP_GENL_A_DP_IDX]) != dp->dp_idx) {
169 VLOG_WARN_RL(&rl, "received dp_idx (%"PRIu32") differs from expected "
170 "(%d)", nl_attr_get_u32(attrs[DP_GENL_A_DP_IDX]),
175 oh = buffer->data = (void *) nl_attr_get(attrs[DP_GENL_A_OPENFLOW]);
176 buffer->size = nl_attr_get_size(attrs[DP_GENL_A_OPENFLOW]);
177 ofp_len = ntohs(oh->length);
178 if (ofp_len != buffer->size) {
180 "ofp_header.length %"PRIu16" != attribute length %zu\n",
181 ofp_len, buffer->size);
182 buffer->size = MIN(ofp_len, buffer->size);
188 ofpbuf_delete(buffer);
192 /* Encapsulates 'msg', which must contain an OpenFlow message, in a Netlink
193 * message, and sends it to the OpenFlow kernel module via 'sock'.
195 * Returns 0 if successful, otherwise a positive errno value. If
196 * 'wait' is true, then the send will wait until buffer space is ready;
197 * otherwise, returns EAGAIN if the 'sock' send buffer is full.
199 * If the send is successful, then the kernel module will receive it, but there
200 * is no guarantee that any reply will not be dropped (see nl_sock_transact()
204 dpif_send_openflow(struct dpif *dp, struct ofpbuf *buffer, bool wait)
206 struct ofp_header *oh;
207 unsigned int dump_flag;
210 uint32_t fixed_buffer[64 / 4];
216 /* The reply to OFPT_STATS_REQUEST may be multiple segments long, so we
217 * need to specify NLM_F_DUMP in the request. */
218 oh = ofpbuf_at_assert(buffer, 0, sizeof *oh);
219 dump_flag = oh->type == OFPT_STATS_REQUEST ? NLM_F_DUMP : 0;
221 ofpbuf_use(&hdr, fixed_buffer, sizeof fixed_buffer);
222 nl_msg_put_genlmsghdr(&hdr, dp->sock, 32, openflow_family,
223 NLM_F_REQUEST | dump_flag, DP_GENL_C_OPENFLOW, 1);
224 nl_msg_put_u32(&hdr, DP_GENL_A_DP_IDX, dp->dp_idx);
225 nla = ofpbuf_put_uninit(&hdr, sizeof *nla);
226 nla->nla_len = sizeof *nla + buffer->size;
227 nla->nla_type = DP_GENL_A_OPENFLOW;
228 pad_bytes = NLA_ALIGN(nla->nla_len) - nla->nla_len;
229 nl_msg_nlmsghdr(&hdr)->nlmsg_len = hdr.size + buffer->size + pad_bytes;
231 iov[0].iov_base = hdr.data;
232 iov[0].iov_len = hdr.size;
233 iov[1].iov_base = buffer->data;
234 iov[1].iov_len = buffer->size;
236 static char zeros[NLA_ALIGNTO];
238 iov[2].iov_base = zeros;
239 iov[2].iov_len = pad_bytes;
241 retval = nl_sock_sendv(dp->sock, iov, n_iov, false);
242 if (retval && retval != EAGAIN) {
243 VLOG_WARN_RL(&rl, "dpif_send_openflow: %s", strerror(retval));
248 /* Creates the datapath represented by 'dp'. Returns 0 if successful,
249 * otherwise a positive errno value. */
251 dpif_add_dp(struct dpif *dp)
253 return send_mgmt_command(dp, DP_GENL_C_ADD_DP, NULL);
256 /* Destroys the datapath represented by 'dp'. Returns 0 if successful,
257 * otherwise a positive errno value. */
259 dpif_del_dp(struct dpif *dp)
261 return send_mgmt_command(dp, DP_GENL_C_DEL_DP, NULL);
264 /* Adds the Ethernet device named 'netdev' to this datapath. Returns 0 if
265 * successful, otherwise a positive errno value. */
267 dpif_add_port(struct dpif *dp, const char *netdev)
269 return send_mgmt_command(dp, DP_GENL_C_ADD_PORT, netdev);
272 /* Removes the Ethernet device named 'netdev' from this datapath. Returns 0
273 * if successful, otherwise a positive errno value. */
275 dpif_del_port(struct dpif *dp, const char *netdev)
277 return send_mgmt_command(dp, DP_GENL_C_DEL_PORT, netdev);
280 static const struct nl_policy openflow_multicast_policy[] = {
281 [DP_GENL_A_DP_IDX] = { .type = NL_A_U32 },
282 [DP_GENL_A_MC_GROUP] = { .type = NL_A_U32 },
285 /* Looks up the Netlink multicast group used by datapath 'dp_idx'. If
286 * successful, stores the multicast group in '*multicast_group' and returns 0.
287 * Otherwise, returns a positve errno value. */
289 lookup_openflow_multicast_group(int dp_idx, int *multicast_group)
291 struct nl_sock *sock;
292 struct ofpbuf request, *reply;
293 struct nlattr *attrs[ARRAY_SIZE(openflow_multicast_policy)];
296 retval = nl_sock_create(NETLINK_GENERIC, 0, 0, 0, &sock);
300 ofpbuf_init(&request, 0);
301 nl_msg_put_genlmsghdr(&request, sock, 0, openflow_family, NLM_F_REQUEST,
302 DP_GENL_C_QUERY_DP, 1);
303 nl_msg_put_u32(&request, DP_GENL_A_DP_IDX, dp_idx);
304 retval = nl_sock_transact(sock, &request, &reply);
305 ofpbuf_uninit(&request);
307 nl_sock_destroy(sock);
310 if (!nl_policy_parse(reply, openflow_multicast_policy, attrs,
311 ARRAY_SIZE(openflow_multicast_policy))) {
312 nl_sock_destroy(sock);
313 ofpbuf_delete(reply);
316 *multicast_group = nl_attr_get_u32(attrs[DP_GENL_A_MC_GROUP]);
317 nl_sock_destroy(sock);
318 ofpbuf_delete(reply);
323 /* Sends the given 'command' to datapath 'dp'. If 'netdev' is nonnull, adds it
324 * to the command as the port name attribute. Returns 0 if successful,
325 * otherwise a positive errno value. */
327 send_mgmt_command(struct dpif *dp, int command, const char *netdev)
329 struct ofpbuf request, *reply;
332 ofpbuf_init(&request, 0);
333 nl_msg_put_genlmsghdr(&request, dp->sock, 32, openflow_family,
334 NLM_F_REQUEST | NLM_F_ACK, command, 1);
335 nl_msg_put_u32(&request, DP_GENL_A_DP_IDX, dp->dp_idx);
337 nl_msg_put_string(&request, DP_GENL_A_PORTNAME, netdev);
339 retval = nl_sock_transact(dp->sock, &request, &reply);
340 ofpbuf_uninit(&request);
341 ofpbuf_delete(reply);