Merge pull request #21055 from yuwata/network-dhcp6-pd-route-lifetime-metric

network: dhcp6pd: set lifetime and route metric

man/systemd.network.xml

@@ -2162,7 +2162,8 @@ Table=1234</programlisting></para>
         <term><varname>RouteMetric=</varname></term>
         <listitem>
           <para>The metric of the route to the delegated prefix subnet. Takes an unsigned integer in
-          the range 0…4294967295. When unset or set to 0, the kernel's default value is used.</para>
+          the range 0…4294967295. When set to 0, the kernel's default value is used. Defaults to 256.
+          </para>
         </listitem>
       </varlistentry>
     </variablelist>

src/libsystemd-network/dhcp6-lease-internal.h

@@ -18,6 +18,7 @@ struct sd_dhcp6_lease {
         size_t serverid_len;
         uint8_t preference;
         bool rapid_commit;
+        triple_timestamp timestamp;
 
         DHCP6IA ia;
         DHCP6IA pd;

src/libsystemd-network/dhcp6-network.c

@@ -47,6 +47,10 @@ int dhcp6_network_bind_udp_socket(int ifindex, struct in6_addr *local_address) {
         if (r < 0)
                 return r;
 
+        r = setsockopt_int(s, SOL_SOCKET, SO_TIMESTAMP, true);
+        if (r < 0)
+                return r;
+
         r = bind(s, &src.sa, sizeof(src.in6));
         if (r < 0)
                 return -errno;

src/libsystemd-network/sd-dhcp6-client.c

@@ -21,6 +21,7 @@
 #include "hexdecoct.h"
 #include "hostname-util.h"
 #include "in-addr-util.h"
+#include "io-util.h"
 #include "network-common.h"
 #include "random-util.h"
 #include "socket-util.h"
@@ -1341,13 +1342,14 @@ static int client_parse_message(
         return 0;
 }
 
-static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, size_t len) {
+static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, size_t len, const triple_timestamp *t) {
         _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL;
         bool rapid_commit;
         int r;
 
         assert(client);
         assert(reply);
+        assert(t);
 
         if (reply->type != DHCP6_MESSAGE_REPLY)
                 return 0;
@@ -1356,6 +1358,8 @@ static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, si
         if (r < 0)
                 return -ENOMEM;
 
+        lease->timestamp = *t;
+
         r = client_parse_message(client, reply, len, lease);
         if (r < 0)
                 return r;
@@ -1375,11 +1379,15 @@ static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, si
         return DHCP6_STATE_BOUND;
 }
 
-static int client_receive_advertise(sd_dhcp6_client *client, DHCP6Message *advertise, size_t len) {
+static int client_receive_advertise(sd_dhcp6_client *client, DHCP6Message *advertise, size_t len, const triple_timestamp *t) {
         _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL;
         uint8_t pref_advertise = 0, pref_lease = 0;
         int r;
 
+        assert(client);
+        assert(advertise);
+        assert(t);
+
         if (advertise->type != DHCP6_MESSAGE_ADVERTISE)
                 return 0;
 
@@ -1387,6 +1395,8 @@ static int client_receive_advertise(sd_dhcp6_client *client, DHCP6Message *adver
         if (r < 0)
                 return r;
 
+        lease->timestamp = *t;
+
         r = client_parse_message(client, advertise, len, lease);
         if (r < 0)
                 return r;
@@ -1417,6 +1427,17 @@ static int client_receive_message(
 
         sd_dhcp6_client *client = userdata;
         DHCP6_CLIENT_DONT_DESTROY(client);
+        /* This needs to be initialized with zero. See #20741. */
+        CMSG_BUFFER_TYPE(CMSG_SPACE_TIMEVAL) control = {};
+        struct iovec iov;
+        struct msghdr msg = {
+                .msg_iov = &iov,
+                .msg_iovlen = 1,
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+        };
+        struct cmsghdr *cmsg;
+        triple_timestamp t = {};
         _cleanup_free_ DHCP6Message *message = NULL;
         ssize_t buflen, len;
         int r = 0;
@@ -1427,9 +1448,8 @@ static int client_receive_message(
 
         buflen = next_datagram_size_fd(fd);
         if (buflen == -ENETDOWN)
-                /* the link is down. Don't return an error or the I/O event
-                   source will be disconnected and we won't be able to receive
-                   packets again when the link comes back. */
+                /* the link is down. Don't return an error or the I/O event source will be disconnected
+                 * and we won't be able to receive packets again when the link comes back. */
                 return 0;
         if (buflen < 0)
                 return buflen;
@@ -1438,7 +1458,9 @@ static int client_receive_message(
         if (!message)
                 return -ENOMEM;
 
-        len = recv(fd, message, buflen, 0);
+        iov = IOVEC_MAKE(message, buflen);
+
+        len = recvmsg_safe(fd, &msg, MSG_DONTWAIT);
         if (len < 0) {
                 /* see comment above for why we shouldn't error out on ENETDOWN. */
                 if (IN_SET(errno, EAGAIN, EINTR, ENETDOWN))
@@ -1452,6 +1474,16 @@ static int client_receive_message(
                 return 0;
         }
 
+        CMSG_FOREACH(cmsg, &msg) {
+                if (cmsg->cmsg_level == SOL_SOCKET &&
+                    cmsg->cmsg_type == SO_TIMESTAMP &&
+                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))
+                        triple_timestamp_from_realtime(&t, timeval_load((struct timeval*) CMSG_DATA(cmsg)));
+        }
+
+        if (!triple_timestamp_is_set(&t))
+                triple_timestamp_get(&t);
+
         if (!IN_SET(message->type, DHCP6_MESSAGE_ADVERTISE, DHCP6_MESSAGE_REPLY, DHCP6_MESSAGE_RECONFIGURE)) {
                 const char *type_str = dhcp6_message_type_to_string(message->type);
                 if (type_str)
@@ -1466,7 +1498,7 @@ static int client_receive_message(
 
         switch (client->state) {
         case DHCP6_STATE_INFORMATION_REQUEST:
-                r = client_receive_reply(client, message, len);
+                r = client_receive_reply(client, message, len, &t);
                 if (r < 0) {
                         log_dhcp6_client_errno(client, r, "Failed to process received reply message, ignoring: %m");
                         return 0;
@@ -1479,7 +1511,7 @@ static int client_receive_message(
                 break;
 
         case DHCP6_STATE_SOLICITATION:
-                r = client_receive_advertise(client, message, len);
+                r = client_receive_advertise(client, message, len, &t);
                 if (r < 0) {
                         log_dhcp6_client_errno(client, r, "Failed to process received advertise message, ignoring: %m");
                         return 0;
@@ -1495,7 +1527,7 @@ static int client_receive_message(
         case DHCP6_STATE_RENEW:
         case DHCP6_STATE_REBIND:
 
-                r = client_receive_reply(client, message, len);
+                r = client_receive_reply(client, message, len, &t);
                 if (r < 0) {
                         log_dhcp6_client_errno(client, r, "Failed to process received reply message, ignoring: %m");
                         return 0;

src/libsystemd-network/sd-dhcp6-lease.c

@@ -11,6 +11,19 @@
 #include "strv.h"
 #include "util.h"
 
+int sd_dhcp6_lease_get_timestamp(sd_dhcp6_lease *lease, clockid_t clock, uint64_t *ret) {
+        assert_return(lease, -EINVAL);
+        assert_return(TRIPLE_TIMESTAMP_HAS_CLOCK(clock), -EOPNOTSUPP);
+        assert_return(clock_supported(clock), -EOPNOTSUPP);
+        assert_return(ret, -EINVAL);
+
+        if (!triple_timestamp_is_set(&lease->timestamp))
+                return -ENODATA;
+
+        *ret = triple_timestamp_by_clock(&lease->timestamp, clock);
+        return 0;
+}
+
 int dhcp6_lease_ia_rebind_expire(const DHCP6IA *ia, uint32_t *expire) {
         DHCP6Address *addr;
         uint32_t valid = 0, t;

src/network/networkd-dhcp-common.h

@@ -10,6 +10,7 @@
 #include "time-util.h"
 
 #define DHCP_ROUTE_METRIC 1024
+#define DHCP6PD_ROUTE_METRIC 256
 
 typedef struct Link Link;
 typedef struct Manager Manager;

src/network/networkd-dhcp6.c

@@ -288,7 +288,7 @@ static int dhcp6_pd_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link
         return 1;
 }
 
-static int dhcp6_pd_request_route(Link *link, const struct in6_addr *prefix) {
+static int dhcp6_pd_request_route(Link *link, const struct in6_addr *prefix, usec_t timestamp_usec, uint32_t lifetime_sec) {
         _cleanup_(route_freep) Route *route = NULL;
         Route *existing;
         int r;
@@ -310,6 +310,7 @@ static int dhcp6_pd_request_route(Link *link, const struct in6_addr *prefix) {
         route->dst_prefixlen = 64;
         route->protocol = RTPROT_DHCP;
         route->priority = link->network->dhcp6_pd_route_metric;
+        route->lifetime = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 
         if (route_get(NULL, link, route, &existing) < 0)
                 link->dhcp6_pd_configured = false;
@@ -420,6 +421,7 @@ static int dhcp6_pd_request_address(
 static int dhcp6_pd_assign_prefix(
                 Link *link,
                 const struct in6_addr *prefix,
+                usec_t timestamp_usec,
                 uint32_t lifetime_preferred,
                 uint32_t lifetime_valid) {
 
@@ -435,7 +437,7 @@ static int dhcp6_pd_assign_prefix(
                         return r;
         }
 
-        r = dhcp6_pd_request_route(link, prefix);
+        r = dhcp6_pd_request_route(link, prefix, timestamp_usec, lifetime_valid);
         if (r < 0)
                 return r;
 
@@ -527,6 +529,7 @@ static int dhcp6_pd_prefix_distribute(
                 Link *dhcp6_link,
                 const struct in6_addr *pd_prefix,
                 uint8_t pd_prefix_len,
+                usec_t timestamp_usec,
                 uint32_t lifetime_preferred,
                 uint32_t lifetime_valid,
                 bool assign_preferred_subnet_id) {
@@ -560,7 +563,7 @@ static int dhcp6_pd_prefix_distribute(
                         continue;
 
                 (void) in6_addr_prefix_to_string(&assigned_prefix, 64, &buf);
-                r = dhcp6_pd_assign_prefix(link, &assigned_prefix, lifetime_preferred, lifetime_valid);
+                r = dhcp6_pd_assign_prefix(link, &assigned_prefix, timestamp_usec, lifetime_preferred, lifetime_valid);
                 if (r < 0) {
                         log_link_warning_errno(link, r, "Failed to assign/update prefix %s: %m", strna(buf));
                         if (link == dhcp6_link)
@@ -746,7 +749,7 @@ static int dhcp6_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *li
         return 1;
 }
 
-static int dhcp6_request_unreachable_route(Link *link, const struct in6_addr *addr, uint8_t prefixlen) {
+static int dhcp6_request_unreachable_route(Link *link, const struct in6_addr *addr, uint8_t prefixlen, usec_t timestamp_usec, uint32_t lifetime_sec) {
         _cleanup_(route_freep) Route *route = NULL;
         _cleanup_free_ char *buf = NULL;
         Route *existing;
@@ -774,6 +777,8 @@ static int dhcp6_request_unreachable_route(Link *link, const struct in6_addr *ad
         route->table = link_get_dhcp6_route_table(link);
         route->type = RTN_UNREACHABLE;
         route->protocol = RTPROT_DHCP;
+        route->priority = DHCP_ROUTE_METRIC;
+        route->lifetime = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 
         if (route_get(link->manager, NULL, route, &existing) < 0)
                 link->dhcp6_configured = false;
@@ -826,12 +831,17 @@ static int dhcp6_pd_prefix_add(Link *link, const struct in6_addr *prefix, uint8_
 }
 
 static int dhcp6_pd_prefix_acquired(Link *dhcp6_link) {
+        usec_t timestamp_usec;
         Link *link;
         int r;
 
         assert(dhcp6_link);
         assert(dhcp6_link->dhcp6_lease);
 
+        r = sd_dhcp6_lease_get_timestamp(dhcp6_link->dhcp6_lease, clock_boottime_or_monotonic(), &timestamp_usec);
+        if (r < 0)
+                return log_link_warning_errno(dhcp6_link, r, "Failed to get timestamp of DHCPv6 lease: %m");
+
         HASHMAP_FOREACH(link, dhcp6_link->manager->links_by_index) {
                 if (link == dhcp6_link)
                         continue;
@@ -857,7 +867,7 @@ static int dhcp6_pd_prefix_acquired(Link *dhcp6_link) {
                 if (r == 0)
                         continue;
 
-                r = dhcp6_request_unreachable_route(dhcp6_link, &pd_prefix, pd_prefix_len);
+                r = dhcp6_request_unreachable_route(dhcp6_link, &pd_prefix, pd_prefix_len, timestamp_usec, lifetime_valid);
                 if (r < 0)
                         return r;
 
@@ -889,6 +899,7 @@ static int dhcp6_pd_prefix_acquired(Link *dhcp6_link) {
                 r = dhcp6_pd_prefix_distribute(dhcp6_link,
                                                &pd_prefix,
                                                pd_prefix_len,
+                                               timestamp_usec,
                                                lifetime_preferred,
                                                lifetime_valid,
                                                true);
@@ -898,6 +909,7 @@ static int dhcp6_pd_prefix_acquired(Link *dhcp6_link) {
                 r = dhcp6_pd_prefix_distribute(dhcp6_link,
                                                &pd_prefix,
                                                pd_prefix_len,
+                                               timestamp_usec,
                                                lifetime_preferred,
                                                lifetime_valid,
                                                false);

src/network/networkd-network.c

@@ -409,7 +409,8 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
                 .dhcp6_pd_announce = true,
                 .dhcp6_pd_assign = true,
                 .dhcp6_pd_manage_temporary_address = true,
-                .dhcp6_pd_subnet_id = -1,
+                .dhcp6_pd_subnet_id = UINT64_MAX,
+                .dhcp6_pd_route_metric = DHCP6PD_ROUTE_METRIC,
 
                 .dhcp_server_bind_to_interface = true,
                 .dhcp_server_emit[SD_DHCP_LEASE_DNS].emit = true,

src/systemd/sd-dhcp6-lease.h

@@ -21,6 +21,7 @@
 
 #include <inttypes.h>
 #include <netinet/in.h>
+#include <sys/types.h>
 
 #include "_sd-common.h"
 
@@ -28,6 +29,8 @@ _SD_BEGIN_DECLARATIONS;
 
 typedef struct sd_dhcp6_lease sd_dhcp6_lease;
 
+int sd_dhcp6_lease_get_timestamp(sd_dhcp6_lease *lease, clockid_t clock, uint64_t *ret);
+
 void sd_dhcp6_lease_reset_address_iter(sd_dhcp6_lease *lease);
 int sd_dhcp6_lease_get_address(sd_dhcp6_lease *lease,
                                struct in6_addr *addr,