Merge pull request #32292 from yuwata/sd-radv-send-on-stop

sd-radv: set only basic information in RA message on stop

2 files changed, 38 insertions, 10 deletions

diff --git a/src/libsystemd-network/sd-radv.c b/src/libsystemd-network/sd-radv.c
index 79210f9e2ca..6a71ce14ff4 100644
--- a/src/libsystemd-network/sd-radv.c
+++ b/src/libsystemd-network/sd-radv.c
@@ -129,9 +129,32 @@ static bool router_lifetime_is_valid(usec_t lifetime_usec) {
                  lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
 }
 
-static int radv_send_router(sd_radv *ra, const struct in6_addr *dst, usec_t lifetime_usec) {
+static int radv_send_router_on_stop(sd_radv *ra) {
+        static const struct nd_router_advert adv = {
+                .nd_ra_type = ND_ROUTER_ADVERT,
+        };
+
+        _cleanup_set_free_ Set *options = NULL;
+        usec_t time_now;
+        int r;
+
+        assert(ra);
+
+        r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
+        if (r < 0)
+                return r;
+
+        if (!ether_addr_is_null(&ra->mac_addr)) {
+                r = ndisc_option_set_link_layer_address(&options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, &ra->mac_addr);
+                if (r < 0)
+                        return r;
+        }
+
+        return ndisc_send(ra->fd, &IN6_ADDR_ALL_NODES_MULTICAST, &adv.nd_ra_hdr, options, time_now);
+}
+
+static int radv_send_router(sd_radv *ra, const struct in6_addr *dst) {
         assert(ra);
-        assert(router_lifetime_is_valid(lifetime_usec));
 
         struct sockaddr_in6 dst_addr = {
                 .sin6_family = AF_INET6,
@@ -139,7 +162,7 @@ static int radv_send_router(sd_radv *ra, const struct in6_addr *dst, usec_t life
         };
         struct nd_router_advert adv = {
                 .nd_ra_type = ND_ROUTER_ADVERT,
-                .nd_ra_router_lifetime = usec_to_be16_sec(lifetime_usec),
+                .nd_ra_router_lifetime = usec_to_be16_sec(ra->lifetime_usec),
                 .nd_ra_retransmit = usec_to_be32_msec(ra->retransmit_usec),
         };
         struct {
@@ -261,7 +284,7 @@ static int radv_process_packet(sd_radv *ra, ICMP6Packet *packet) {
         if (r < 0 && r != -ENODATA) /* null address is allowed */
                 return log_radv_errno(ra, r, "Failed to get sender address of RS, ignoring: %m");
 
-        r = radv_send_router(ra, &src, ra->lifetime_usec);
+        r = radv_send_router(ra, &src);
         if (r < 0)
                 return log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", IN6_ADDR_TO_STRING(&src));
 
@@ -299,7 +322,7 @@ static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
         if (r < 0)
                 goto fail;
 
-        r = radv_send_router(ra, NULL, ra->lifetime_usec);
+        r = radv_send_router(ra, NULL);
         if (r < 0)
                 log_radv_errno(ra, r, "Unable to send Router Advertisement, ignoring: %m");
 
@@ -362,7 +385,7 @@ int sd_radv_stop(sd_radv *ra) {
         /* RFC 4861, Section 6.2.5:
          * the router SHOULD transmit one or more (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
          * multicast Router Advertisements on the interface with a Router Lifetime field of zero. */
-        r = radv_send_router(ra, NULL, 0);
+        r = radv_send_router_on_stop(ra);
         if (r < 0)
                 log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero, ignoring: %m");
 
@@ -679,7 +702,7 @@ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
                 return 0;
 
         /* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
-        r = radv_send_router(ra, NULL, ra->lifetime_usec);
+        r = radv_send_router(ra, NULL);
         if (r < 0)
                 log_radv_errno(ra, r, "Unable to send Router Advertisement for added prefix %s, ignoring: %m", addr_p);
         else
@@ -775,7 +798,7 @@ int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p) {
                 return 0;
 
         /* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
-        r = radv_send_router(ra, NULL, ra->lifetime_usec);
+        r = radv_send_router(ra, NULL);
         if (r < 0)
                 log_radv_errno(ra, r, "Unable to send Router Advertisement for added route prefix %s, ignoring: %m",
                                strna(addr_p));
@@ -847,7 +870,7 @@ int sd_radv_add_pref64_prefix(sd_radv *ra, sd_radv_pref64_prefix *p) {
                 return 0;
 
         /* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
-        r = radv_send_router(ra, NULL, ra->lifetime_usec);
+        r = radv_send_router(ra, NULL);
         if (r < 0)
                 log_radv_errno(ra, r, "Unable to send Router Advertisement for added PREF64 prefix %s, ignoring: %m",
                                strna(addr_p));
diff --git a/src/libsystemd-network/test-ndisc-ra.c b/src/libsystemd-network/test-ndisc-ra.c
index c5f10cc7955..76f4d7ba3f2 100644
--- a/src/libsystemd-network/test-ndisc-ra.c
+++ b/src/libsystemd-network/test-ndisc-ra.c
@@ -294,8 +294,13 @@ static void verify_message(const uint8_t *buf, size_t len) {
         /* verify only up to known options, rest is not yet implemented */
         for (size_t i = 0, m = MIN(len, sizeof(advertisement)); i < m; i++) {
                 if (test_stopped)
+                        /* on stop, many header fields are zero */
                         switch (i) {
-                        case 6 ... 7: /* router lifetime must be zero on stop. */
+                        case 4: /* hop limit */
+                        case 5: /* flags */
+                        case 6 ... 7: /* router lifetime */
+                        case 8 ... 11: /* reachable time */
+                        case 12 ... 15: /* retrans timer */
                                 assert_se(buf[i] == 0);
                                 continue;
                         }