router: create ICMPv6 socket per interface
authorHans Dedecker <dedeckeh@gmail.com>
Wed, 3 Apr 2019 14:29:19 +0000 (16:29 +0200)
committerHans Dedecker <dedeckeh@gmail.com>
Fri, 5 Apr 2019 08:30:18 +0000 (10:30 +0200)
Get rid of the global raw ICMPv6 socket by creating a raw ICMPv6 socket per
interface. This fixes an open raw ICMPv6 socket in case all ra interfaces
are configured as disabled.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
src/config.c
src/odhcpd.h
src/router.c

index 3e1b3f1..16f003b 100644 (file)
@@ -430,6 +430,7 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
                iface->name = strcpy(new_name, name);
                iface->avl.key = iface->name;
+               iface->router_event.uloop.fd = -1;
                iface->dhcpv6_event.uloop.fd = -1;
                iface->ndp_event.uloop.fd = -1;
                iface->dhcpv4_event.uloop.fd = -1;
index 80f416d..42d0954 100644 (file)
@@ -209,6 +209,7 @@ struct interface {
        size_t addr6_len;
 
        // RA runtime data
+       struct odhcpd_event router_event;
        struct uloop_timeout timer_rs;
 
        // DHCPv6 runtime data
index 976e28a..9055367 100644 (file)
@@ -38,7 +38,6 @@ static void handle_icmpv6(void *addr, void *data, size_t len,
 static void trigger_router_advert(struct uloop_timeout *event);
 static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info);
 
-static struct odhcpd_event router_event = {.uloop = {.fd = -1}, .handle_dgram = handle_icmpv6, };
 static struct netevent_handler router_netevent_handler = { .cb = router_netevent_cb, };
 
 static FILE *fp_route = NULL;
@@ -48,78 +47,8 @@ static FILE *fp_route = NULL;
 
 int router_init(void)
 {
-       struct icmp6_filter filt;
        int ret = 0;
 
-       /* Open ICMPv6 socket */
-       router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
-       if (router_event.uloop.fd < 0) {
-               syslog(LOG_ERR, "socket(AF_INET6): %m");
-               ret = -1;
-               goto out;
-       }
-
-       /* Let the kernel compute our checksums */
-       int val = 2;
-       if (setsockopt(router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
-                               &val, sizeof(val)) < 0) {
-               syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
-               ret = -1;
-               goto out;
-       }
-
-       /* This is required by RFC 4861 */
-       val = 255;
-       if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
-                               &val, sizeof(val)) < 0) {
-               syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
-               ret = -1;
-               goto out;
-       }
-
-       if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
-                               &val, sizeof(val)) < 0) {
-               syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
-               ret = -1;
-               goto out;
-       }
-
-       /* We need to know the source interface */
-       val = 1;
-       if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
-                               &val, sizeof(val)) < 0) {
-               syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
-               ret = -1;
-               goto out;
-       }
-
-       if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
-                               &val, sizeof(val)) < 0) {
-               syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
-               ret = -1;
-               goto out;
-       }
-
-       /* Don't loop back */
-       val = 0;
-       if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
-                               &val, sizeof(val)) < 0) {
-               syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
-               ret = -1;
-               goto out;
-       }
-
-       /* Filter ICMPv6 package types */
-       ICMP6_FILTER_SETBLOCKALL(&filt);
-       ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
-       ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
-       if (setsockopt(router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
-                               &filt, sizeof(filt)) < 0) {
-               syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
-               ret = -1;
-               goto out;
-       }
-
        if (!(fp_route = fopen("/proc/net/ipv6_route", "r"))) {
                syslog(LOG_ERR, "fopen(/proc/net/ipv6_route): %m");
                ret = -1;
@@ -129,22 +58,12 @@ int router_init(void)
        if (netlink_add_netevent_handler(&router_netevent_handler) < 0) {
                syslog(LOG_ERR, "Failed to add netevent handler");
                ret = -1;
-               goto out;
        }
 
-       /* Register socket */
-       odhcpd_register(&router_event);
 out:
-       if (ret < 0) {
-               if (router_event.uloop.fd > 0) {
-                       close(router_event.uloop.fd);
-                       router_event.uloop.fd = -1;
-               }
-
-               if (fp_route) {
-                       fclose(fp_route);
-                       fp_route = NULL;
-               }
+       if (ret < 0 && fp_route) {
+               fclose(fp_route);
+               fp_route = NULL;
        }
 
        return ret;
@@ -153,48 +72,149 @@ out:
 
 int router_setup_interface(struct interface *iface, bool enable)
 {
-       struct ipv6_mreq mreq;
        int ret = 0;
 
-       if (!fp_route || router_event.uloop.fd < 0) {
+       if (!fp_route) {
                ret = -1;
                goto out;
        }
 
-       uloop_timeout_cancel(&iface->timer_rs);
-       iface->timer_rs.cb = NULL;
 
-       memset(&mreq, 0, sizeof(mreq));
-       mreq.ipv6mr_interface = iface->ifindex;
-       inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
-       setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
-                       &mreq, sizeof(mreq));
+       if ((!enable || iface->ra == MODE_DISABLED) && iface->router_event.uloop.fd >= 0) {
+               if (!iface->master) {
+                       uloop_timeout_cancel(&iface->timer_rs);
+                       iface->timer_rs.cb = NULL;
 
-       inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
-       setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
-                       &mreq, sizeof(mreq));
-
-       if (!enable) {
-               if (iface->ra == MODE_SERVER || (iface->ra == MODE_RELAY && !iface->master))
                        trigger_router_advert(&iface->timer_rs);
-       } else {
+               }
+
+               uloop_fd_delete(&iface->router_event.uloop);
+               close(iface->router_event.uloop.fd);
+               iface->router_event.uloop.fd = -1;
+       } else if (enable && iface->ra != MODE_DISABLED) {
+               struct icmp6_filter filt;
+               struct ipv6_mreq mreq;
+               int val = 2;
+
+               if (iface->router_event.uloop.fd < 0) {
+                       /* Open ICMPv6 socket */
+                       iface->router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC,
+                                                             IPPROTO_ICMPV6);
+                       if (iface->router_event.uloop.fd < 0) {
+                               syslog(LOG_ERR, "socket(AF_INET6): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       if (setsockopt(iface->router_event.uloop.fd, SOL_SOCKET, SO_BINDTODEVICE,
+                                      iface->ifname, strlen(iface->ifname)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(SO_BINDTODEVICE): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       /* Let the kernel compute our checksums */
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
+                                      &val, sizeof(val)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       /* This is required by RFC 4861 */
+                       val = 255;
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
+                                      &val, sizeof(val)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
+                                      &val, sizeof(val)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       /* We need to know the source interface */
+                       val = 1;
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
+                                      &val, sizeof(val)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
+                                      &val, sizeof(val)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       /* Don't loop back */
+                       val = 0;
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
+                                      &val, sizeof(val)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       /* Filter ICMPv6 package types */
+                       ICMP6_FILTER_SETBLOCKALL(&filt);
+                       ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
+                       ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
+                       if (setsockopt(iface->router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
+                                      &filt, sizeof(filt)) < 0) {
+                               syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
+                               ret = -1;
+                               goto out;
+                       }
+
+                       iface->router_event.handle_dgram = handle_icmpv6;
+                       odhcpd_register(&iface->router_event);
+               } else {
+                       uloop_timeout_cancel(&iface->timer_rs);
+                       iface->timer_rs.cb = NULL;
+
+                       memset(&mreq, 0, sizeof(mreq));
+                       mreq.ipv6mr_interface = iface->ifindex;
+                       inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
+                       setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
+                                  &mreq, sizeof(mreq));
+
+                       inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
+                       setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
+                                  &mreq, sizeof(mreq));
+               }
+
+               memset(&mreq, 0, sizeof(mreq));
+               mreq.ipv6mr_interface = iface->ifindex;
+               inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
+
                if (iface->ra == MODE_RELAY && iface->master) {
                        inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
                        forward_router_solicitation(iface);
-               } else if (iface->ra == MODE_SERVER && !iface->master) {
+               } else if (iface->ra == MODE_SERVER) {
                        iface->timer_rs.cb = trigger_router_advert;
                        uloop_timeout_set(&iface->timer_rs, 1000);
                }
 
-               if (iface->ra == MODE_RELAY || (iface->ra == MODE_SERVER && !iface->master)) {
-                       if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6,
-                                       IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
-                               ret = -1;
-                               syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
-                       }
+               if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6,
+                              IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+                       ret = -1;
+                       syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
+                       goto out;
                }
        }
 out:
+       if (ret < 0 && iface->router_event.uloop.fd >= 0) {
+               close(iface->router_event.uloop.fd);
+               iface->router_event.uloop.fd = -1;
+       }
+
        return ret;
 }
 
@@ -677,8 +697,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 
        syslog(LOG_INFO, "Sending a RA on %s", iface->name);
 
-       odhcpd_send(router_event.uloop.fd,
-                       &dest, iov, ARRAY_SIZE(iov), iface);
+       odhcpd_send(iface->router_event.uloop.fd, &dest, iov, ARRAY_SIZE(iov), iface);
 
        free(pfxs);
        free(routes);
@@ -743,7 +762,7 @@ static void forward_router_solicitation(const struct interface *iface)
        all_routers.sin6_scope_id = iface->ifindex;
 
        syslog(LOG_NOTICE, "Sending RS to %s", iface->name);
-       odhcpd_send(router_event.uloop.fd, &all_routers, &iov, 1, iface);
+       odhcpd_send(iface->router_event.uloop.fd, &all_routers, &iov, 1, iface);
 }
 
 
@@ -813,6 +832,6 @@ static void forward_router_advertisement(const struct interface *iface, uint8_t
 
                syslog(LOG_NOTICE, "Forward a RA on %s", c->name);
 
-               odhcpd_send(router_event.uloop.fd, &all_nodes, &iov, 1, c);
+               odhcpd_send(c->router_event.uloop.fd, &all_nodes, &iov, 1, c);
        }
 }