ra: align ifindex resolving

[project/odhcp6c.git] / src / ra.c

diff --git a/src/ra.c b/src/ra.c
index c1f3d0373cf47ca311e297d8ed48e2d25bb853fd..32a30973736b032ec258be75234352a18130836f 100644 (file)
--- a/src/ra.c
+++ b/src/ra.c
@@ -27,6 +27,7 @@
 
 #include <net/if.h>
 #include <arpa/inet.h>
+#include <sys/ioctl.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <netinet/in.h>
@@ -58,6 +59,10 @@ static volatile int rs_attempt = 0;
 static struct in6_addr lladdr = IN6ADDR_ANY_INIT;
 static unsigned int ra_options = 0;
 static unsigned int ra_holdoff_interval = 0;
+static int ra_hoplimit = 0;
+static int ra_mtu = 0;
+static int ra_reachable = 0;
+static int ra_retransmit = 0;
 
 struct {
        struct icmp6_hdr hdr;
@@ -72,6 +77,8 @@ static void ra_send_rs(int signal __attribute__((unused)));
 int ra_init(const char *ifname, const struct in6_addr *ifid,
                unsigned int options, unsigned int holdoff_interval)
 {
+       struct ifreq ifr;
+
        ra_options = options;
        ra_holdoff_interval = holdoff_interval;
 
@@ -80,11 +87,12 @@ int ra_init(const char *ifname, const struct in6_addr *ifid,
        if (sock < 0)
                goto failure;
 
-       if_index = if_nametoindex(ifname);
-       if (!if_index)
+       memset(&ifr, 0, sizeof(ifr));
+       strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
+       if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
                goto failure;
 
-       strncpy(if_name, ifname, sizeof(if_name) - 1);
+       if_index = ifr.ifr_ifindex;
        lladdr = *ifid;
 
        rtnl = socket(AF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_ROUTE);
@@ -272,44 +280,64 @@ static bool ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data
        return opt == end;
 }
 
-int ra_conf_hoplimit(int newvalue)
+static bool ra_set_hoplimit(int val)
 {
-       static int value = 0;
-
-       if (newvalue > 0)
-               value = newvalue;
+       if (val > 0 && val != ra_hoplimit) {
+               ra_hoplimit = val;
+               return true;
+       }
 
-       return value;
+       return false;
 }
 
-int ra_conf_mtu(int newvalue)
+static bool ra_set_mtu(int val)
 {
-       static int value = 0;
+       if (val >= 1280 && val <= 65535 && ra_mtu != val) {
+               ra_mtu = val;
+               return true;
+       }
 
-       if (newvalue >= 1280 && newvalue <= 65535)
-               value = newvalue;
+       return false;
+}
+
+static bool ra_set_reachable(int val)
+{
+       if (val > 0 && val <= 3600000 && ra_reachable != val) {
+               ra_reachable = val;
+               return true;
+       }
 
-       return value;
+       return false;
 }
 
-int ra_conf_reachable(int newvalue)
+static bool ra_set_retransmit(int val)
 {
-       static int value = 0;
+       if (val > 0 && val <= 60000 && ra_retransmit != val) {
+               ra_retransmit = val;
+               return true;
+       }
 
-       if (newvalue > 0 && newvalue <= 3600000)
-               value = newvalue;
+       return false;
+}
 
-       return value;
+int ra_get_hoplimit(void)
+{
+       return ra_hoplimit;
 }
 
-int ra_conf_retransmit(int newvalue)
+int ra_get_mtu(void)
 {
-       static int value = 0;
+       return ra_mtu;
+}
 
-       if (newvalue > 0 && newvalue <= 60000)
-               value = newvalue;
+int ra_get_reachable(void)
+{
+       return ra_reachable;
+}
 
-       return value;
+int ra_get_retransmit(void)
+{
+       return ra_retransmit;
 }
 
 bool ra_process(void)
@@ -353,6 +381,9 @@ bool ra_process(void)
                        .msg_controllen = sizeof(cmsg_buf),
                        .msg_flags = 0
                };
+               struct icmpv6_opt *opt;
+               uint32_t router_valid;
+               int hlim = 0;
 
                ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
                if (len <= 0)
@@ -361,7 +392,6 @@ bool ra_process(void)
                if (IN6_IS_ADDR_UNSPECIFIED(&lladdr))
                        continue;
 
-               int hlim = 0;
                for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
                                ch = CMSG_NXTHDR(&msg, ch))
                        if (ch->cmsg_level == IPPROTO_IPV6 &&
@@ -371,17 +401,24 @@ bool ra_process(void)
                if (!ra_icmpv6_valid(&from, hlim, buf, len))
                        continue;
 
-               // Stop sending solicits
-               if (rs_attempt > 0) {
-                       alarm(0);
-                       rs_attempt = 0;
-               }
-
                if (!found) {
                        odhcp6c_expire();
                        found = true;
                }
-               uint32_t router_valid = ntohs(adv->nd_ra_router_lifetime);
+
+               router_valid = ntohs(adv->nd_ra_router_lifetime);
+
+               /* RFC4861 §6.3.7
+                * Once the host sends a Router Solicitation, and receives a valid
+                * Router Advertisement with a non-zero Router Lifetime, the host MUST
+                * desist from sending additional solicitations on that interface
+                * Moreover, a host SHOULD send at least one solicitation in the case
+                * where an advertisement is received prior to having sent a solicitation.
+                */
+               if (rs_attempt > 0 && router_valid > 0) {
+                       alarm(0);
+                       rs_attempt = 0;
+               }
 
                // Parse default route
                entry->target = any;
@@ -397,18 +434,17 @@ bool ra_process(void)
                                                0, ra_holdoff_interval);
 
                // Parse hoplimit
-               ra_conf_hoplimit(adv->nd_ra_curhoplimit);
+               changed |= ra_set_hoplimit(adv->nd_ra_curhoplimit);
 
                // Parse ND parameters
-               ra_conf_reachable(ntohl(adv->nd_ra_reachable));
-               ra_conf_retransmit(ntohl(adv->nd_ra_retransmit));
+               changed |= ra_set_reachable(ntohl(adv->nd_ra_reachable));
+               changed |= ra_set_retransmit(ntohl(adv->nd_ra_retransmit));
 
                // Evaluate options
-               struct icmpv6_opt *opt;
                icmpv6_for_each_option(opt, &adv[1], &buf[len]) {
                        if (opt->type == ND_OPT_MTU) {
                                uint32_t *mtu = (uint32_t*)&opt->data[2];
-                               ra_conf_mtu(ntohl(*mtu));
+                               changed |= ra_set_mtu(ntohl(*mtu));
                        } else if (opt->type == ND_OPT_ROUTE_INFORMATION && opt->len <= 3) {
                                struct icmpv6_opt_route_info *ri = (struct icmpv6_opt_route_info *)opt;