ofproto/discovery.c

   1 /*
   2  * Copyright (c) 2008, 2009 Nicira Networks.
   3  *
   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:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #include <config.h>
  18 #include "discovery.h"
  19 #include <errno.h>
  20 #include <inttypes.h>
  21 #include <net/if.h>
  22 #include <regex.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include "dhcp-client.h"
  26 #include "dhcp.h"
  27 #include "dpif.h"
  28 #include "netdev.h"
  29 #include "openflow/openflow.h"
  30 #include "packets.h"
  31 #include "status.h"
  32 #include "vconn-ssl.h"
  33
  34 #define THIS_MODULE VLM_discovery
  35 #include "vlog.h"
  36
  37 struct discovery {
  38     char *re;
  39     bool update_resolv_conf;
  40     regex_t *regex;
  41     struct dhclient *dhcp;
  42     int n_changes;
  43     struct status_category *ss_cat;
  44 };
  45
  46 static void modify_dhcp_request(struct dhcp_msg *, void *aux);
  47 static bool validate_dhcp_offer(const struct dhcp_msg *, void *aux);
  48
  49 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 60);
  50
  51 static void
  52 discovery_status_cb(struct status_reply *sr, void *d_)
  53 {
  54     struct discovery *d = d_;
  55
  56     status_reply_put(sr, "accept-remote=%s", d->re);
  57     status_reply_put(sr, "n-changes=%d", d->n_changes);
  58     if (d->dhcp) {
  59         status_reply_put(sr, "state=%s", dhclient_get_state(d->dhcp));
  60         status_reply_put(sr, "state-elapsed=%u",
  61                          dhclient_get_state_elapsed(d->dhcp));
  62         if (dhclient_is_bound(d->dhcp)) {
  63             uint32_t ip = dhclient_get_ip(d->dhcp);
  64             uint32_t netmask = dhclient_get_netmask(d->dhcp);
  65             uint32_t router = dhclient_get_router(d->dhcp);
  66
  67             const struct dhcp_msg *cfg = dhclient_get_config(d->dhcp);
  68             uint32_t dns_server;
  69             char *domain_name;
  70             int i;
  71
  72             status_reply_put(sr, "ip="IP_FMT, IP_ARGS(&ip));
  73             status_reply_put(sr, "netmask="IP_FMT, IP_ARGS(&netmask));
  74             if (router) {
  75                 status_reply_put(sr, "router="IP_FMT, IP_ARGS(&router));
  76             }
  77
  78             for (i = 0; dhcp_msg_get_ip(cfg, DHCP_CODE_DNS_SERVER, i,
  79                                         &dns_server);
  80                  i++) {
  81                 status_reply_put(sr, "dns%d="IP_FMT, i, IP_ARGS(&dns_server));
  82             }
  83
  84             domain_name = dhcp_msg_get_string(cfg, DHCP_CODE_DOMAIN_NAME);
  85             if (domain_name) {
  86                 status_reply_put(sr, "domain=%s", domain_name);
  87                 free(domain_name);
  88             }
  89
  90             status_reply_put(sr, "lease-remaining=%u",
  91                              dhclient_get_lease_remaining(d->dhcp));
  92         }
  93     }
  94 }
  95
  96 int
  97 discovery_create(const char *re, bool update_resolv_conf,
  98                  struct dpif *dpif, struct switch_status *ss,
  99                  struct discovery **discoveryp)
 100 {
 101     struct discovery *d;
 102     char local_name[IF_NAMESIZE];
 103     int error;
 104
 105     d = xzalloc(sizeof *d);
 106
 107     /* Controller regular expression. */
 108     error = discovery_set_accept_controller_re(d, re);
 109     if (error) {
 110         goto error_free;
 111     }
 112     d->update_resolv_conf = update_resolv_conf;
 113
 114     /* Initialize DHCP client. */
 115     error = dpif_port_get_name(dpif, ODPP_LOCAL,
 116                                local_name, sizeof local_name);
 117     if (error) {
 118         VLOG_ERR("failed to query datapath local port: %s", strerror(error));
 119         goto error_regfree;
 120     }
 121     error = dhclient_create(local_name, modify_dhcp_request,
 122                             validate_dhcp_offer, d, &d->dhcp);
 123     if (error) {
 124         VLOG_ERR("failed to initialize DHCP client: %s", strerror(error));
 125         goto error_regfree;
 126     }
 127     dhclient_set_max_timeout(d->dhcp, 3);
 128     dhclient_init(d->dhcp, 0);
 129
 130     d->ss_cat = switch_status_register(ss, "discovery",
 131                                        discovery_status_cb, d);
 132
 133     *discoveryp = d;
 134     return 0;
 135
 136 error_regfree:
 137     regfree(d->regex);
 138     free(d->regex);
 139 error_free:
 140     free(d);
 141     *discoveryp = 0;
 142     return error;
 143 }
 144
 145 void
 146 discovery_destroy(struct discovery *d)
 147 {
 148     if (d) {
 149         free(d->re);
 150         regfree(d->regex);
 151         free(d->regex);
 152         dhclient_destroy(d->dhcp);
 153         switch_status_unregister(d->ss_cat);
 154         free(d);
 155     }
 156 }
 157
 158 void
 159 discovery_set_update_resolv_conf(struct discovery *d,
 160                                  bool update_resolv_conf)
 161 {
 162     d->update_resolv_conf = update_resolv_conf;
 163 }
 164
 165 int
 166 discovery_set_accept_controller_re(struct discovery *d, const char *re_)
 167 {
 168     regex_t *regex;
 169     int error;
 170     char *re;
 171
 172     re = (!re_ ? xstrdup(vconn_ssl_is_configured() ? "^ssl:.*" : "^tcp:.*")
 173           : re_[0] == '^' ? xstrdup(re_) : xasprintf("^%s", re_));
 174     regex = xmalloc(sizeof *regex);
 175     error = regcomp(regex, re, REG_NOSUB | REG_EXTENDED);
 176     if (error) {
 177         size_t length = regerror(error, regex, NULL, 0);
 178         char *buffer = xmalloc(length);
 179         regerror(error, regex, buffer, length);
 180         VLOG_WARN("%s: %s", re, buffer);
 181         free(regex);
 182         free(re);
 183         return EINVAL;
 184     } else {
 185         if (d->regex) {
 186             regfree(d->regex);
 187             free(d->regex);
 188         }
 189         free(d->re);
 190
 191         d->regex = regex;
 192         d->re = re;
 193         return 0;
 194     }
 195 }
 196
 197 void
 198 discovery_question_connectivity(struct discovery *d)
 199 {
 200     if (d->dhcp) {
 201         dhclient_force_renew(d->dhcp, 15);
 202     }
 203 }
 204
 205 bool
 206 discovery_run(struct discovery *d, char **controller_name)
 207 {
 208     if (!d->dhcp) {
 209         *controller_name = NULL;
 210         return true;
 211     }
 212
 213     dhclient_run(d->dhcp);
 214     if (!dhclient_changed(d->dhcp)) {
 215         return false;
 216     }
 217
 218     dhclient_configure_netdev(d->dhcp);
 219     if (d->update_resolv_conf) {
 220         dhclient_update_resolv_conf(d->dhcp);
 221     }
 222
 223     if (dhclient_is_bound(d->dhcp)) {
 224         *controller_name = dhcp_msg_get_string(dhclient_get_config(d->dhcp),
 225                                                DHCP_CODE_OFP_CONTROLLER_VCONN);
 226         VLOG_INFO("%s: discovered controller", *controller_name);
 227         d->n_changes++;
 228     } else {
 229         *controller_name = NULL;
 230         if (d->n_changes) {
 231             VLOG_INFO("discovered controller no longer available");
 232             d->n_changes++;
 233         }
 234     }
 235     return true;
 236 }
 237
 238 void
 239 discovery_wait(struct discovery *d)
 240 {
 241     if (d->dhcp) {
 242         dhclient_wait(d->dhcp);
 243     }
 244 }
 245
 246 static void
 247 modify_dhcp_request(struct dhcp_msg *msg, void *aux UNUSED)
 248 {
 249     dhcp_msg_put_string(msg, DHCP_CODE_VENDOR_CLASS, "OpenFlow");
 250 }
 251
 252 static bool
 253 validate_dhcp_offer(const struct dhcp_msg *msg, void *d_)
 254 {
 255     const struct discovery *d = d_;
 256     char *vconn_name;
 257     bool accept;
 258
 259     vconn_name = dhcp_msg_get_string(msg, DHCP_CODE_OFP_CONTROLLER_VCONN);
 260     if (!vconn_name) {
 261         VLOG_WARN_RL(&rl, "rejecting DHCP offer missing controller vconn");
 262         return false;
 263     }
 264     accept = !regexec(d->regex, vconn_name, 0, NULL, 0);
 265     if (!accept) {
 266         VLOG_WARN_RL(&rl, "rejecting controller vconn that fails to match %s",
 267                      d->re);
 268     }
 269     free(vconn_name);
 270     return accept;
 271 }