improve the reliability of gratuitous arp by sending both request and reply, also...
[project/relayd.git] / route.c
diff --git a/route.c b/route.c
index 25f949e..cbb624e 100644 (file)
--- a/route.c
+++ b/route.c
@@ -42,100 +42,97 @@ static void rtnl_flush(void)
        close(fd);
 }
 
+enum {
+       RULE_F_ADD = (1 << 0),
+       RULE_F_DEFGW_WORKAROUND = (1 << 1),
+};
+
+static int get_route_table(struct relayd_interface *rif)
+{
+       if (rif)
+               return rif->rt_table;
+       else
+               return local_route_table;
+}
+
 static void
-rtnl_route_request(struct relayd_interface *rif, struct relayd_host *host,
-                  struct relayd_route *route, bool add)
+rtnl_rule_request(struct relayd_interface *rif, int flags)
 {
        static struct {
                struct nlmsghdr nl;
                struct rtmsg rt;
                struct {
                        struct rtattr rta;
-                       uint8_t ipaddr[4];
-               } __packed dst;
-               struct {
-                       struct rtattr rta;
                        int table;
                } __packed table;
                struct {
                        struct rtattr rta;
-                       int ifindex;
+                       char ifname[IFNAMSIZ + 1];
                } __packed dev;
-               struct {
-                       struct rtattr rta;
-                       uint8_t ipaddr[4];
-               } __packed gw;
        } __packed req = {
                .rt = {
                        .rtm_family = AF_INET,
-                       .rtm_dst_len = 32,
-                       .rtm_table = RT_TABLE_MAIN,
+                       .rtm_table = RT_TABLE_UNSPEC,
+                       .rtm_scope = RT_SCOPE_UNIVERSE,
+                       .rtm_protocol = RTPROT_BOOT,
                },
                .table.rta = {
-                       .rta_type = RTA_TABLE,
+                       .rta_type = FRA_TABLE,
                        .rta_len = sizeof(req.table),
                },
-               .dst.rta = {
-                       .rta_len = sizeof(req.dst),
-               },
-               .dev.rta = {
-                       .rta_type = RTA_OIF,
-                       .rta_len = sizeof(req.dev),
-               },
-               .gw.rta = {
-                       .rta_type = RTA_GATEWAY,
-                       .rta_len = sizeof(req.gw),
-               },
        };
-       int pktlen = sizeof(req);
+       const char *ifname = "lo";
+       int padding = sizeof(req.dev.ifname);
 
-       req.dev.ifindex = host->rif->sll.sll_ifindex;
-       req.table.table = rif->rt_table;
+       if (rif)
+               ifname = rif->ifname;
 
-       req.nl.nlmsg_flags = NLM_F_REQUEST;
-       if (add) {
-               req.nl.nlmsg_type = RTM_NEWROUTE;
-               req.nl.nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
-
-               req.rt.rtm_protocol = RTPROT_BOOT;
-               if (route) {
-                       req.rt.rtm_scope = RT_SCOPE_UNIVERSE;
-               } else {
-                       req.rt.rtm_scope = RT_SCOPE_LINK;
-               }
-               req.rt.rtm_type = RTN_UNICAST;
+       if (!(flags & RULE_F_DEFGW_WORKAROUND)) {
+               req.dev.rta.rta_type = FRA_IFNAME;
+               padding -= strlen(ifname) + 1;
+               strcpy(req.dev.ifname, ifname);
+               req.dev.rta.rta_len = sizeof(req.dev.rta) + strlen(ifname) + 1;
        } else {
-               req.nl.nlmsg_type = RTM_DELROUTE;
-               req.rt.rtm_scope = RT_SCOPE_NOWHERE;
+               req.dev.rta.rta_type = FRA_PRIORITY;
+               req.dev.rta.rta_len = sizeof(req.dev.rta) + sizeof(uint32_t);
+               padding -= sizeof(uint32_t);
+               *((uint32_t *) &req.dev.ifname) = 1;
        }
+       req.table.table = get_route_table(rif);
+       req.nl.nlmsg_len = sizeof(req) - padding;
 
-       req.dst.rta.rta_type = RTA_DST;
-       if (route) {
-               DPRINTF(2, "%s: add route to "IP_FMT"/%d via "IP_FMT"\n",
-                       host->rif->ifname, IP_BUF(route->dest), route->mask, IP_BUF(host->ipaddr));
-               if (!route->mask) {
-                       /* No DST -> reuse the DST attribute as the gateway attribute */
-                       memcpy(req.dst.ipaddr, host->ipaddr, sizeof(req.dst.ipaddr));
-                       req.dst.rta.rta_type = RTA_GATEWAY;
-                       pktlen -= sizeof(req.gw);
-                       req.rt.rtm_dst_len = 0;
-               } else {
-                       memcpy(req.gw.ipaddr, host->ipaddr, sizeof(req.gw.ipaddr));
-                       memcpy(req.dst.ipaddr, route->dest, sizeof(req.dst.ipaddr));
-                       req.rt.rtm_dst_len = route->mask;
-               }
+       req.nl.nlmsg_flags = NLM_F_REQUEST;
+       if (flags & RULE_F_ADD) {
+               req.nl.nlmsg_type = RTM_NEWRULE;
+               req.nl.nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
+
+               req.rt.rtm_type = RTN_UNICAST;
        } else {
-               pktlen -= sizeof(req.gw);
-               req.rt.rtm_dst_len = 32;
-               memcpy(req.dst.ipaddr, host->ipaddr, sizeof(req.dst.ipaddr));
+               req.nl.nlmsg_type = RTM_DELRULE;
+               req.rt.rtm_type = RTN_UNSPEC;
        }
 
-       req.nl.nlmsg_len = pktlen;
-       send(rtnl_sock.fd, &req, pktlen, 0);
+       send(rtnl_sock.fd, &req, req.nl.nlmsg_len, 0);
        rtnl_flush();
 }
 
-static void rtnl_rule_request(struct relayd_interface *rif, bool add)
+struct rtnl_addr {
+       struct rtattr rta;
+       uint8_t ipaddr[4];
+} __packed;
+
+static struct rtnl_addr *
+rtnl_add_addr(struct rtnl_addr *addr, int *len, int type, const uint8_t *ipaddr)
+{
+       addr->rta.rta_type = type;
+       memcpy(addr->ipaddr, ipaddr, 4);
+       *len += sizeof(*addr);
+       return addr + 1;
+}
+
+static void
+rtnl_route_request(struct relayd_interface *rif, struct relayd_host *host,
+                  struct relayd_route *route, bool add)
 {
        static struct {
                struct nlmsghdr nl;
@@ -146,44 +143,80 @@ static void rtnl_rule_request(struct relayd_interface *rif, bool add)
                } __packed table;
                struct {
                        struct rtattr rta;
-                       char ifname[IFNAMSIZ + 1];
+                       int ifindex;
                } __packed dev;
+               struct rtnl_addr addr[3];
        } __packed req = {
                .rt = {
                        .rtm_family = AF_INET,
-                       .rtm_table = RT_TABLE_UNSPEC,
-                       .rtm_scope = RT_SCOPE_UNIVERSE,
-                       .rtm_protocol = RTPROT_BOOT,
+                       .rtm_dst_len = 32,
+                       .rtm_table = RT_TABLE_MAIN,
                },
                .table.rta = {
-                       .rta_type = FRA_TABLE,
+                       .rta_type = RTA_TABLE,
                        .rta_len = sizeof(req.table),
                },
                .dev.rta = {
-                       .rta_type = FRA_IFNAME,
+                       .rta_type = RTA_OIF,
+                       .rta_len = sizeof(req.dev),
                },
+               .addr[0].rta.rta_len = sizeof(struct rtnl_addr),
+               .addr[1].rta.rta_len = sizeof(struct rtnl_addr),
+               .addr[2].rta.rta_len = sizeof(struct rtnl_addr),
        };
+       int pktlen = sizeof(req) - sizeof(req.addr);
+       struct rtnl_addr *addr = &req.addr[0];
+       const char *ifname = "loopback";
 
-       int padding = sizeof(req.dev.ifname);
-       padding -= strlen(rif->ifname) + 1;
-
-       strcpy(req.dev.ifname, rif->ifname);
-       req.dev.rta.rta_len = sizeof(req.dev.rta) + strlen(rif->ifname) + 1;
-       req.table.table = rif->rt_table;
-       req.nl.nlmsg_len = sizeof(req) - padding;
+       req.dev.ifindex = host->rif->sll.sll_ifindex;
+       req.table.table = get_route_table(rif);
 
        req.nl.nlmsg_flags = NLM_F_REQUEST;
        if (add) {
-               req.nl.nlmsg_type = RTM_NEWRULE;
-               req.nl.nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
+               req.nl.nlmsg_type = RTM_NEWROUTE;
+               req.nl.nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
 
+               req.rt.rtm_protocol = RTPROT_BOOT;
+               if (route) {
+                       req.rt.rtm_scope = RT_SCOPE_UNIVERSE;
+               } else {
+                       req.rt.rtm_scope = RT_SCOPE_LINK;
+               }
                req.rt.rtm_type = RTN_UNICAST;
        } else {
-               req.nl.nlmsg_type = RTM_DELRULE;
-               req.rt.rtm_type = RTN_UNSPEC;
+               req.nl.nlmsg_type = RTM_DELROUTE;
+               req.rt.rtm_scope = RT_SCOPE_NOWHERE;
        }
 
-       send(rtnl_sock.fd, &req, req.nl.nlmsg_len, 0);
+       if (rif)
+               ifname = rif->ifname;
+
+       if (route) {
+               DPRINTF(2, "%s: add route to "IP_FMT"/%d via "IP_FMT" (%s)\n", ifname,
+                       IP_BUF(route->dest), route->mask, IP_BUF(host->ipaddr),
+                       host->rif->ifname);
+
+               req.rt.rtm_dst_len = route->mask;
+               if (route->mask)
+                       addr = rtnl_add_addr(addr, &pktlen, RTA_DST, route->dest);
+               addr = rtnl_add_addr(addr, &pktlen, RTA_GATEWAY, host->ipaddr);
+       } else {
+               DPRINTF(2, "%s: add host route to "IP_FMT" (%s)\n", ifname,
+                       IP_BUF(host->ipaddr), host->rif->ifname);
+               addr = rtnl_add_addr(addr, &pktlen, RTA_DST, host->ipaddr);
+               req.rt.rtm_dst_len = 32;
+       }
+
+       /* local route */
+       if (!rif)
+               addr = rtnl_add_addr(addr, &pktlen, RTA_PREFSRC, local_addr);
+
+       req.nl.nlmsg_len = pktlen;
+       if (route)
+               rtnl_rule_request(rif, RULE_F_DEFGW_WORKAROUND | RULE_F_ADD);
+       send(rtnl_sock.fd, &req, pktlen, 0);
+       if (route)
+               rtnl_rule_request(rif, RULE_F_DEFGW_WORKAROUND);
        rtnl_flush();
 }
 
@@ -198,17 +231,19 @@ rtnl_route_set(struct relayd_host *host, struct relayd_route *route, bool add)
 
                rtnl_route_request(rif, host, route, add);
        }
+       if (local_route_table)
+               rtnl_route_request(NULL, host, route, add);
 }
 
 void relayd_add_interface_routes(struct relayd_interface *rif)
 {
        rif->rt_table = route_table++;
-       rtnl_rule_request(rif, true);
+       rtnl_rule_request(rif, RULE_F_ADD);
 }
 
 void relayd_del_interface_routes(struct relayd_interface *rif)
 {
-       rtnl_rule_request(rif, false);
+       rtnl_rule_request(rif, 0);
 }
 
 #ifndef NDA_RTA
@@ -313,21 +348,28 @@ static void rtnl_cb(struct uloop_fd *fd, unsigned int events)
        } while (1);
 }
 
-int relayd_rtnl_init(void)
+static void rtnl_dump_request(int nlmsg_type)
 {
-       struct sockaddr_nl snl_local;
        static struct {
                struct nlmsghdr nlh;
                struct rtgenmsg g;
        } req = {
                .nlh = {
                        .nlmsg_len = sizeof(req),
-                       .nlmsg_type = RTM_GETNEIGH,
                        .nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST,
                        .nlmsg_pid = 0,
                },
                .g.rtgen_family = AF_INET,
        };
+       req.nlh.nlmsg_type = nlmsg_type;
+       req.nlh.nlmsg_seq = rtnl_seq;
+       send(rtnl_sock.fd, &req, sizeof(req), 0);
+       rtnl_seq++;
+}
+
+int relayd_rtnl_init(void)
+{
+       struct sockaddr_nl snl_local;
 
        rtnl_sock.fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
        if (rtnl_sock.fd < 0) {
@@ -348,14 +390,15 @@ int relayd_rtnl_init(void)
 
        rtnl_seq = time(NULL);
        rtnl_dump_seq = rtnl_seq;
-       req.nlh.nlmsg_seq = rtnl_seq;
-       send(rtnl_sock.fd, &req, sizeof(req), 0);
+       rtnl_dump_request(RTM_GETNEIGH);
+       rtnl_rule_request(NULL, RULE_F_ADD);
 
        return 0;
 }
 
 void relayd_rtnl_done(void)
 {
+       rtnl_rule_request(NULL, 0);
        uloop_fd_delete(&rtnl_sock);
        close(rtnl_sock.fd);
 }