[ovs-dev,RFC,ovn,1/2] controller: add ipv6 prefix delegation state machine
diff mbox series

Message ID 174829e66cca3d1a90200d3cbbc858e8856a1f68.1572024147.git.lorenzo.bianconi@redhat.com
State New
Headers show
Series
  • Add IPv6 Prefix delegation (RFC3633)
Related show

Commit Message

Lorenzo Bianconi Oct. 25, 2019, 5:36 p.m. UTC
Introduce Ipv6 Prefix delegation state machine according to RFC 3633
https://tools.ietf.org/html/rfc3633.
Add dhcp6_server_pkt controller action to parse advertise/reply from
IPv6 delegation server. Advertise/reply are parsed running respectively:
- pinctrl_parse_dhcv6_advt
- pinctrl_parse_dhcv6_reply
The IPv6 requesting router starts sending dhcpv6 solicit through the logical
router ported marked with ipv6_prefix_delegationn set to true.
Save IPv6 prefix received by IPv6 delegation router in the options columns of
SB port binding table in order to be reused by Router Advertisement framework
run by ovn logical router pipeline

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 controller/pinctrl.c  | 543 ++++++++++++++++++++++++++++++++++++++++++
 include/ovn/actions.h |   9 +-
 lib/actions.c         |  22 ++
 lib/ovn-l7.h          |  19 ++
 tests/ovn.at          |   6 +
 utilities/ovn-trace.c |   2 +
 6 files changed, 600 insertions(+), 1 deletion(-)

Patch
diff mbox series

diff --git a/controller/pinctrl.c b/controller/pinctrl.c
index d826da186..7907ea8e0 100644
--- a/controller/pinctrl.c
+++ b/controller/pinctrl.c
@@ -269,6 +269,17 @@  static void pinctrl_ip_mcast_handle_igmp(
     const struct match *md,
     struct ofpbuf *userdata);
 
+static void init_ipv6_prefixd(void);
+static void destroy_ipv6_prefixd(void);
+static void ipv6_prefixd_wait(long long int timeout);
+static void
+prepare_ipv6_prefix_req(struct ovsdb_idl_index *sbrec_port_binding_by_datapath,
+                        struct ovsdb_idl_index *sbrec_port_binding_by_name,
+                        const struct hmap *local_datapaths)
+    OVS_REQUIRES(pinctrl_mutex);
+static void
+send_ipv6_prefix_msg(struct rconn *swconn, long long int *send_prefixd_time)
+    OVS_REQUIRES(pinctrl_mutex);
 static bool may_inject_pkts(void);
 
 static void init_put_vport_bindings(void);
@@ -440,6 +451,7 @@  pinctrl_init(void)
     init_put_mac_bindings();
     init_send_garps_rarps();
     init_ipv6_ras();
+    init_ipv6_prefixd();
     init_buffered_packets_map();
     init_event_table();
     ip_mcast_snoop_init();
@@ -526,6 +538,55 @@  set_actions_and_enqueue_msg(struct rconn *swconn,
     ofpbuf_uninit(&ofpacts);
 }
 
+static struct shash ipv6_prefixd;
+
+enum {
+    PREFIX_SOLICIT,
+    PREFIX_PENDING,
+    PREFIX_DONE,
+};
+
+struct ipv6_prefixd_state {
+    long long int next_announce;
+    struct in6_addr ipv6_addr;
+    struct eth_addr ea;
+    int64_t port_key;
+    int64_t metadata;
+    struct in6_addr prefix;
+    unsigned plife_time;
+    unsigned vlife_time;
+    unsigned t1;
+    unsigned t2;
+    int8_t plen;
+    int state;
+};
+
+static void
+init_ipv6_prefixd(void)
+{
+    shash_init(&ipv6_prefixd);
+}
+
+static void
+ipv6_prefixd_delete(struct ipv6_prefixd_state *pfd)
+{
+    if (pfd) {
+        free(pfd);
+    }
+}
+
+static void
+destroy_ipv6_prefixd(void)
+{
+    struct shash_node *iter, *next;
+    SHASH_FOR_EACH_SAFE (iter, next, &ipv6_prefixd) {
+        struct ipv6_prefixd_state *pfd = iter->data;
+        ipv6_prefixd_delete(pfd);
+        shash_delete(&ipv6_prefixd, iter);
+    }
+    shash_destroy(&ipv6_prefixd);
+}
+
 struct buffer_info {
     struct ofpbuf ofpacts;
     struct dp_packet *p;
@@ -949,6 +1010,255 @@  pinctrl_handle_tcp_reset(struct rconn *swconn, const struct flow *ip_flow,
     dp_packet_uninit(&packet);
 }
 
+static void
+pinctrl_parse_dhcv6_advt(struct rconn *swconn, const struct flow *ip_flow,
+                         struct dp_packet *pkt_in, const struct match *md,
+                         struct ofpbuf *userdata)
+{
+    struct udp_header *udp_in = dp_packet_l4(pkt_in);
+    unsigned char *in_dhcpv6_data = (unsigned char *)(udp_in + 1);
+    size_t dlen = MIN(ntohs(udp_in->udp_len), dp_packet_l4_size(pkt_in));
+    uint8_t *data, *end = (uint8_t *)udp_in + dlen;
+    int len = 0;
+
+    data = xmalloc(dlen);
+    if (!data) {
+        return;
+    }
+
+    in_dhcpv6_data += 4;
+
+    while (in_dhcpv6_data < end) {
+        struct dhcpv6_opt_header *in_opt =
+             (struct dhcpv6_opt_header *)in_dhcpv6_data;
+        int opt_len = sizeof *in_opt + ntohs(in_opt->len);
+
+        if (dlen < opt_len + len) {
+            goto out;
+        }
+
+        switch (ntohs(in_opt->code)) {
+        case DHCPV6_OPT_IA_PD: {
+            int orig_len = len, hdr_len = 0, size = sizeof *in_opt + 12;
+
+            memcpy(&data[len], in_opt, size);
+            in_opt = (struct dhcpv6_opt_header *)(in_dhcpv6_data + size);
+            len += size;
+
+            while (size < opt_len) {
+                int flen = sizeof *in_opt + ntohs(in_opt->len);
+
+                if (dlen < flen + len) {
+                    goto out;
+                }
+
+                if (ntohs(in_opt->code) == DHCPV6_OPT_IA_PREFIX) {
+                    memcpy(&data[len], in_opt, flen);
+                    hdr_len += flen;
+                    len += flen;
+                }
+                if (ntohs(in_opt->code) == DHCPV6_OPT_STATUS_CODE) {
+                   struct dhcpv6_opt_status *status;
+
+                   status = (struct dhcpv6_opt_status *)in_opt;
+                   if (ntohs(status->status_code)) {
+                       goto out;
+                   }
+                }
+                size += flen;
+                in_opt = (struct dhcpv6_opt_header *)(in_dhcpv6_data + size);
+            }
+            in_opt = (struct dhcpv6_opt_header *)&data[orig_len];
+            in_opt->len = htons(hdr_len + 12);
+            break;
+        }
+        case DHCPV6_OPT_SERVER_ID_CODE:
+        case DHCPV6_OPT_CLIENT_ID_CODE:
+            memcpy(&data[len], in_opt, opt_len);
+            len += opt_len;
+            break;
+        default:
+            break;
+        }
+        in_dhcpv6_data += opt_len;
+    }
+
+    uint64_t packet_stub[256 / 8];
+    struct dp_packet packet;
+
+    dp_packet_use_stub(&packet, packet_stub, sizeof packet_stub);
+    eth_compose(&packet, ip_flow->dl_dst, ip_flow->dl_src, ETH_TYPE_IPV6,
+                IPV6_HEADER_LEN);
+
+    struct udp_header *udp_h = compose_ipv6(&packet, IPPROTO_UDP,
+                                            &ip_flow->ipv6_src,
+                                            &ip_flow->ipv6_dst, 0, 0, 255,
+                                            len + UDP_HEADER_LEN + 4);
+    udp_h->udp_len = htons(len + UDP_HEADER_LEN + 4);
+    udp_h->udp_csum = 0;
+    packet_set_udp_port(&packet, htons(546), htons(547));
+
+    unsigned char *dhcp_hdr = (unsigned char *)(udp_h + 1);
+    *dhcp_hdr = DHCPV6_MSG_TYPE_REQUEST;
+    memcpy(dhcp_hdr + 4, data, len);
+
+    uint32_t csum = packet_csum_pseudoheader6(dp_packet_l3(&packet));
+    csum = csum_continue(csum, udp_h, dp_packet_size(&packet) -
+                         ((const unsigned char *)udp_h -
+                          (const unsigned char *)dp_packet_eth(&packet)));
+    udp_h->udp_csum = csum_finish(csum);
+    if (!udp_h->udp_csum) {
+        udp_h->udp_csum = htons(0xffff);
+    }
+
+    if (ip_flow->vlans[0].tci & htons(VLAN_CFI)) {
+        eth_push_vlan(&packet, htons(ETH_TYPE_VLAN_8021Q),
+                      ip_flow->vlans[0].tci);
+    }
+
+    set_actions_and_enqueue_msg(swconn, &packet, md, userdata);
+    dp_packet_uninit(&packet);
+
+out:
+    free(data);
+}
+
+static struct ipv6_prefixd_state *
+pinctrl_find_prefixd_state(const struct flow *ip_flow)
+{
+    struct shash_node *iter;
+
+    SHASH_FOR_EACH (iter, &ipv6_prefixd) {
+        struct ipv6_prefixd_state *pfd = iter->data;
+        if (IN6_ARE_ADDR_EQUAL(&pfd->ipv6_addr, &ip_flow->ipv6_dst) &&
+            eth_addr_equals(pfd->ea, ip_flow->dl_dst)) {
+            return pfd;
+        }
+    }
+    return NULL;
+}
+
+static void
+pinctrl_prefixd_state_handler(const struct flow *ip_flow,
+                              struct in6_addr addr, char prefix_len,
+                              unsigned t1, unsigned t2,
+                              unsigned plife_time, unsigned vlife_time)
+{
+    struct ipv6_prefixd_state *pfd;
+
+    pfd = pinctrl_find_prefixd_state(ip_flow);
+    if (pfd) {
+        pfd->state = PREFIX_PENDING;
+        pfd->plife_time = plife_time;
+        pfd->vlife_time = vlife_time;
+        pfd->plen = prefix_len;
+        pfd->prefix = addr;
+        pfd->t1 = t1;
+        pfd->t2 = t2;
+    }
+}
+
+static void
+pinctrl_parse_dhcv6_reply(struct dp_packet *pkt_in,
+                          const struct flow *ip_flow)
+    OVS_REQUIRES(pinctrl_mutex)
+{
+    struct udp_header *udp_in = dp_packet_l4(pkt_in);
+    unsigned char *in_dhcpv6_data = (unsigned char *)(udp_in + 1);
+    size_t dlen = MIN(ntohs(udp_in->udp_len), dp_packet_l4_size(pkt_in));
+    unsigned t1 = 0, t2 = 0, vlife_time = 0, plife_time = 0;
+    uint8_t *end = (uint8_t *)udp_in + dlen;
+    uint8_t prefix_len = 0;
+    struct in6_addr ipv6;
+    bool status = false;
+
+    memset(&ipv6, 0, sizeof (struct in6_addr));
+    in_dhcpv6_data += 4;
+    while (in_dhcpv6_data < end) {
+        struct dhcpv6_opt_header *in_opt =
+             (struct dhcpv6_opt_header *)in_dhcpv6_data;
+        int opt_len = sizeof *in_opt + ntohs(in_opt->len);
+
+        if (in_dhcpv6_data + opt_len > end) {
+            break;
+        }
+
+        switch (ntohs(in_opt->code)) {
+        case DHCPV6_OPT_IA_PD: {
+            int size = sizeof *in_opt + 12;
+            in_opt = (struct dhcpv6_opt_header *)(in_dhcpv6_data + size);
+            struct dhcpv6_opt_ia_na *ia_na =
+                (struct dhcpv6_opt_ia_na *)in_dhcpv6_data;
+
+            t1 = ntohl(ia_na->t1);
+            t2 = ntohl(ia_na->t2);
+            if (t1 > t2 && t2 > 0) {
+                break;
+            }
+
+            while (size < opt_len) {
+                if (ntohs(in_opt->code) == DHCPV6_OPT_IA_PREFIX) {
+                    struct dhcpv6_opt_ia_prefix *ia_hdr =
+                        (struct dhcpv6_opt_ia_prefix *)(in_dhcpv6_data + size);
+
+                    if (ia_hdr->plen > sizeof(struct in6_addr)) {
+                        break;
+                    }
+
+                    prefix_len = ia_hdr->plen;
+                    plife_time = ntohl(ia_hdr->plife_time);
+                    vlife_time = ntohl(ia_hdr->vlife_time);
+                    memcpy(&ipv6, &ia_hdr->ipv6, sizeof (struct in6_addr));
+                }
+                if (ntohs(in_opt->code) == DHCPV6_OPT_STATUS_CODE) {
+                   struct dhcpv6_opt_status *status_hdr;
+
+                   status_hdr = (struct dhcpv6_opt_status *)in_opt;
+                   status = ntohs(status_hdr->status_code) == 0;
+                }
+                size += sizeof *in_opt + ntohs(in_opt->len);
+                in_opt = (struct dhcpv6_opt_header *)(in_dhcpv6_data + size);
+            }
+            break;
+        }
+        default:
+            break;
+        }
+        in_dhcpv6_data += opt_len;
+    }
+    if (status) {
+        pinctrl_prefixd_state_handler(ip_flow, ipv6, prefix_len,
+                                      t1, t2, plife_time, vlife_time);
+    }
+}
+
+static void
+pinctrl_handle_dhcp6_server(struct rconn *swconn, const struct flow *ip_flow,
+                            struct dp_packet *pkt_in, const struct match *md,
+                            struct ofpbuf *userdata)
+{
+    if (ip_flow->dl_type != htons(ETH_TYPE_IPV6) ||
+        ip_flow->nw_proto != IPPROTO_UDP) {
+        return;
+    }
+
+    struct udp_header *udp_in = dp_packet_l4(pkt_in);
+    unsigned char *dhcp_hdr = (unsigned char *)(udp_in + 1);
+
+    switch (*dhcp_hdr) {
+    case DHCPV6_MSG_TYPE_ADVT:
+        pinctrl_parse_dhcv6_advt(swconn, ip_flow, pkt_in, md, userdata);
+        break;
+    case DHCPV6_MSG_TYPE_REPLY:
+        ovs_mutex_lock(&pinctrl_mutex);
+        pinctrl_parse_dhcv6_reply(pkt_in, ip_flow);
+        ovs_mutex_unlock(&pinctrl_mutex);
+        break;
+    default:
+        break;
+    }
+}
+
 /* Called with in the pinctrl_handler thread context. */
 static void
 pinctrl_handle_put_dhcp_opts(
@@ -1980,6 +2290,10 @@  process_packet_in(struct rconn *swconn, const struct ofp_header *msg)
         pinctrl_handle_bind_vport(&pin.flow_metadata.flow, &userdata);
         ovs_mutex_unlock(&pinctrl_mutex);
         break;
+    case ACTION_OPCODE_DHCP6_SERVER:
+        pinctrl_handle_dhcp6_server(swconn, &headers, &packet,
+                                    &pin.flow_metadata, &userdata);
+        break;
 
     default:
         VLOG_WARN_RL(&rl, "unrecognized packet-in opcode %"PRIu32,
@@ -2050,6 +2364,7 @@  pinctrl_handler(void *arg_)
     static long long int send_garp_rarp_time = LLONG_MAX;
     /* Next multicast query (IGMP) in ms. */
     static long long int send_mcast_query_time = LLONG_MAX;
+    static long long int send_prefixd_time = LLONG_MAX;
 
     swconn = rconn_create(5, 0, DSCP_DEFAULT, 1 << OFP13_VERSION);
 
@@ -2103,6 +2418,7 @@  pinctrl_handler(void *arg_)
                 ovs_mutex_lock(&pinctrl_mutex);
                 send_garp_rarp_run(swconn, &send_garp_rarp_time);
                 send_ipv6_ras(swconn, &send_ipv6_ra_time);
+                send_ipv6_prefix_msg(swconn, &send_prefixd_time);
                 send_mac_binding_buffered_pkts(swconn);
                 ovs_mutex_unlock(&pinctrl_mutex);
 
@@ -2115,6 +2431,7 @@  pinctrl_handler(void *arg_)
         send_garp_rarp_wait(send_garp_rarp_time);
         ipv6_ra_wait(send_ipv6_ra_time);
         ip_mcast_querier_wait(send_mcast_query_time);
+        ipv6_prefixd_wait(send_prefixd_time);
 
         new_seq = seq_read(pinctrl_handler_seq);
         seq_wait(pinctrl_handler_seq, new_seq);
@@ -2165,6 +2482,8 @@  pinctrl_run(struct ovsdb_idl_txn *ovnsb_idl_txn,
                            sbrec_port_binding_by_name, br_int, chassis,
                            local_datapaths, active_tunnels);
     prepare_ipv6_ras(local_datapaths);
+    prepare_ipv6_prefix_req(sbrec_port_binding_by_datapath,
+                            sbrec_port_binding_by_name, local_datapaths);
     sync_dns_cache(dns_table);
     controller_event_run(ovnsb_idl_txn, ce_table, chassis);
     ip_mcast_sync(ovnsb_idl_txn, chassis, local_datapaths,
@@ -2405,6 +2724,149 @@  send_ipv6_ras(struct rconn *swconn, long long int *send_ipv6_ra_time)
     }
 }
 
+static void
+compose_prefixd_solicit(struct dp_packet *b,
+                        const struct eth_addr eth_src,
+                        const struct eth_addr eth_dst,
+                        const struct in6_addr *ipv6_src,
+                        const struct in6_addr *ipv6_dst)
+{
+    eth_compose(b, eth_dst, eth_src, ETH_TYPE_IPV6, IPV6_HEADER_LEN);
+
+    int len = UDP_HEADER_LEN + 4 + sizeof(struct dhcpv6_opt_server_id) +
+              sizeof(struct dhcpv6_opt_ia_na);
+    struct udp_header *udp_h = compose_ipv6(b, IPPROTO_UDP, ipv6_src,
+                                            ipv6_dst, 0, 0, 255, len);
+    udp_h->udp_len = htons(len);
+    udp_h->udp_csum = 0;
+    packet_set_udp_port(b, htons(546), htons(547));
+
+    unsigned char *dhcp_hdr = (unsigned char *)(udp_h + 1);
+    *dhcp_hdr = DHCPV6_MSG_TYPE_SOLICIT;
+
+    struct dhcpv6_opt_server_id *opt_client_id =
+        (struct dhcpv6_opt_server_id *)(dhcp_hdr + 4);
+    opt_client_id->opt.code = htons(DHCPV6_OPT_CLIENT_ID_CODE);
+    opt_client_id->opt.len = htons(sizeof(struct dhcpv6_opt_server_id) -
+                                   sizeof(struct dhcpv6_opt_header));
+    opt_client_id->duid_type = htons(DHCPV6_DUID_LL);
+    opt_client_id->hw_type = htons(DHCPV6_HW_TYPE_ETH);
+    opt_client_id->mac = eth_src;
+
+    struct dhcpv6_opt_ia_na *ia_pd =
+            (struct dhcpv6_opt_ia_na *)(opt_client_id + 1);
+    ia_pd->opt.code = htons(DHCPV6_OPT_IA_PD);
+    ia_pd->opt.len = htons(sizeof(struct dhcpv6_opt_ia_na) -
+                           sizeof(struct dhcpv6_opt_header));
+    ia_pd->iaid = htonl(1);
+    ia_pd->t1 = htonl(0xffffffff);
+    ia_pd->t2 = htonl(0xffffffff);
+
+    uint32_t csum = packet_csum_pseudoheader6(dp_packet_l3(b));
+    csum = csum_continue(csum, udp_h, dp_packet_size(b) -
+                         ((const unsigned char *)udp_h -
+                          (const unsigned char *)dp_packet_eth(b)));
+    udp_h->udp_csum = csum_finish(csum);
+    if (!udp_h->udp_csum) {
+        udp_h->udp_csum = htons(0xffff);
+    }
+}
+
+#define IPV6_PREFIXD_TIMEOUT    3000LL
+static long long int
+ipv6_prefixd_send(struct rconn *swconn, struct ipv6_prefixd_state *pfd)
+{
+    long long int cur_time = time_msec();
+    if (cur_time < pfd->next_announce) {
+        return pfd->next_announce;
+    }
+
+    uint64_t packet_stub[256 / 8];
+    struct dp_packet packet;
+
+    struct eth_addr eth_dst;
+    eth_dst = (struct eth_addr) ETH_ADDR_C(33,33,00,01,00,02);
+    struct in6_addr ipv6_dst;
+    ipv6_parse("ff02::1:2", &ipv6_dst);
+
+    dp_packet_use_stub(&packet, packet_stub, sizeof packet_stub);
+    compose_prefixd_solicit(&packet, pfd->ea, eth_dst, &pfd->ipv6_addr,
+                            &ipv6_dst);
+
+    uint64_t ofpacts_stub[4096 / 8];
+    struct ofpbuf ofpacts = OFPBUF_STUB_INITIALIZER(ofpacts_stub);
+
+    /* Set MFF_LOG_DATAPATH and MFF_LOG_INPORT. */
+    uint32_t dp_key = pfd->metadata;
+    uint32_t port_key = pfd->port_key;
+    put_load(dp_key, MFF_LOG_DATAPATH, 0, 64, &ofpacts);
+    put_load(port_key, MFF_LOG_INPORT, 0, 32, &ofpacts);
+    put_load(1, MFF_LOG_FLAGS, MLF_LOCAL_ONLY_BIT, 1, &ofpacts);
+    struct ofpact_resubmit *resubmit = ofpact_put_RESUBMIT(&ofpacts);
+    resubmit->in_port = OFPP_CONTROLLER;
+    resubmit->table_id = OFTABLE_LOG_INGRESS_PIPELINE;
+
+    struct ofputil_packet_out po = {
+        .packet = dp_packet_data(&packet),
+        .packet_len = dp_packet_size(&packet),
+        .buffer_id = UINT32_MAX,
+        .ofpacts = ofpacts.data,
+        .ofpacts_len = ofpacts.size,
+    };
+
+    match_set_in_port(&po.flow_metadata, OFPP_CONTROLLER);
+    enum ofp_version version = rconn_get_version(swconn);
+    enum ofputil_protocol proto = ofputil_protocol_from_ofp_version(version);
+    queue_msg(swconn, ofputil_encode_packet_out(&po, proto));
+    dp_packet_uninit(&packet);
+    ofpbuf_uninit(&ofpacts);
+    pfd->next_announce = cur_time + IPV6_PREFIXD_TIMEOUT;
+
+    return pfd->next_announce;
+}
+
+static bool ipv6_prefixd_should_inject(void)
+{
+    struct shash_node *iter;
+
+    SHASH_FOR_EACH (iter, &ipv6_prefixd) {
+        struct ipv6_prefixd_state *pfd = iter->data;
+        if (pfd->state == PREFIX_SOLICIT) {
+            return true;
+        }
+        if (pfd->state == PREFIX_DONE &&
+            pfd->next_announce < time_msec()) {
+            pfd->state = PREFIX_SOLICIT;
+            return true;
+        }
+    }
+    return false;
+}
+
+static void
+ipv6_prefixd_wait(long long int timeout)
+{
+    if (ipv6_prefixd_should_inject()) {
+        poll_timer_wait_until(timeout);
+    }
+}
+
+static void
+send_ipv6_prefix_msg(struct rconn *swconn, long long int *send_prefixd_time)
+    OVS_REQUIRES(pinctrl_mutex)
+{
+    struct shash_node *iter;
+
+    *send_prefixd_time = LLONG_MAX;
+    SHASH_FOR_EACH (iter, &ipv6_prefixd) {
+        struct ipv6_prefixd_state *pfd = iter->data;
+        long long int next_msg = ipv6_prefixd_send(swconn, pfd);
+        if (*send_prefixd_time > next_msg) {
+            *send_prefixd_time = next_msg;
+        }
+    }
+}
+
 /* Called by pinctrl_run(). Runs with in the main ovn-controller
  * thread context. */
 static void
@@ -2482,6 +2944,85 @@  prepare_ipv6_ras(const struct hmap *local_datapaths)
 
 }
 
+static void
+prepare_ipv6_prefix_req(struct ovsdb_idl_index *sbrec_port_binding_by_datapath,
+                        struct ovsdb_idl_index *sbrec_port_binding_by_name,
+                        const struct hmap *local_datapaths)
+    OVS_REQUIRES(pinctrl_mutex)
+{
+    const struct local_datapath *ld;
+    struct ipv6_prefixd_state *pfd;
+    bool changed = false;
+    int i;
+
+    HMAP_FOR_EACH (ld, hmap_node, local_datapaths) {
+        struct sbrec_port_binding *target = sbrec_port_binding_index_init_row(
+            sbrec_port_binding_by_datapath);
+        sbrec_port_binding_index_set_datapath(target, ld->datapath);
+
+        struct sbrec_port_binding *pb;
+        SBREC_PORT_BINDING_FOR_EACH_EQUAL(pb, target,
+                                          sbrec_port_binding_by_datapath) {
+            if (!smap_get_bool(&pb->options, "ipv6_prefix_delegation",
+                               false)) {
+                continue;
+            }
+
+            const char *peer_s = smap_get(&pb->options, "peer");
+            if (!peer_s) {
+                continue;
+            }
+
+            const struct sbrec_port_binding *peer
+                = lport_lookup_by_name(sbrec_port_binding_by_name, peer_s);
+            if (!peer) {
+                continue;
+            }
+
+            struct lport_addresses laddrs;
+            for (i = 0; i < pb->n_mac; i++) {
+                if (extract_lsp_addresses(pb->mac[i], &laddrs) &&
+                    laddrs.n_ipv6_addrs > 0 &&
+                    !in6_is_lla(&laddrs.ipv6_addrs[0].addr)) {
+                        break;
+                    }
+            }
+            if (i == pb->n_mac) {
+                continue;
+            }
+
+            pfd = shash_find_data(&ipv6_prefixd, pb->logical_port);
+            if (!pfd) {
+                pfd = xzalloc(sizeof *pfd);
+                pfd->ipv6_addr = laddrs.ipv6_addrs[0].addr;
+                pfd->ea = laddrs.ea;
+                pfd->metadata = peer->datapath->tunnel_key;
+                pfd->port_key = peer->tunnel_key;
+                shash_add(&ipv6_prefixd, pb->logical_port, pfd);
+                pfd->next_announce = time_msec() + IPV6_PREFIXD_TIMEOUT;
+                changed = true;
+            } else if (pfd->state == PREFIX_PENDING) {
+                char prefix_str[INET6_ADDRSTRLEN + 1] = {};
+                struct smap options;
+
+                pfd->state = PREFIX_DONE;
+                pfd->next_announce = time_msec() + pfd->t1 * 1000;
+                ipv6_string_mapped(prefix_str, &pfd->prefix);
+                smap_clone(&options, &pb->options);
+                smap_add_format(&options, "ipv6_ra_pd_list", "%s/%d",
+                                prefix_str, pfd->plen);
+                sbrec_port_binding_set_options(pb, &options);
+                smap_destroy(&options);
+            }
+        }
+        sbrec_port_binding_index_destroy_row(target);
+    }
+
+    if (changed) {
+        notify_pinctrl_handler();
+    }
+}
+
 /* Called by pinctrl_run(). Runs with in the main ovn-controller
  * thread context. */
 void
@@ -2504,6 +3045,7 @@  pinctrl_destroy(void)
     free(pinctrl.br_int_name);
     destroy_send_garps_rarps();
     destroy_ipv6_ras();
+    destroy_ipv6_prefixd();
     destroy_buffered_packets_map();
     event_table_destroy();
     destroy_put_mac_bindings();
@@ -3991,6 +4533,7 @@  may_inject_pkts(void)
 {
     return (!shash_is_empty(&ipv6_ras) ||
             !shash_is_empty(&send_garp_rarp_data) ||
+            ipv6_prefixd_should_inject() ||
             !ovs_list_is_empty(&mcast_query_list) ||
             !ovs_list_is_empty(&buffered_mac_bindings));
 }
diff --git a/include/ovn/actions.h b/include/ovn/actions.h
index 4e2f4d28d..b17e740ba 100644
--- a/include/ovn/actions.h
+++ b/include/ovn/actions.h
@@ -88,7 +88,8 @@  struct ovn_extend_table;
     OVNACT(OVNFIELD_LOAD,     ovnact_load)            \
     OVNACT(CHECK_PKT_LARGER,  ovnact_check_pkt_larger) \
     OVNACT(TRIGGER_EVENT,     ovnact_controller_event) \
-    OVNACT(BIND_VPORT,        ovnact_bind_vport)
+    OVNACT(BIND_VPORT,        ovnact_bind_vport)      \
+    OVNACT(DHCP6_SERVER_PKT,  ovnact_nest)
 
 /* enum ovnact_type, with a member OVNACT_<ENUM> for each action. */
 enum OVS_PACKED_ENUM ovnact_type {
@@ -533,6 +534,12 @@  enum action_opcode {
      *    MFF_LOG_INPORT.
      */
     ACTION_OPCODE_BIND_VPORT,
+
+    /* dhcp6_server_pkt { ...actions ...}."
+     *
+     *  The actions, in OpenFlow 1.3 format, follow the action_header.
+     */
+    ACTION_OPCODE_DHCP6_SERVER,
 };
 
 /* Header. */
diff --git a/lib/actions.c b/lib/actions.c
index c8c9cc5fd..137d3c47a 100644
--- a/lib/actions.c
+++ b/lib/actions.c
@@ -2153,6 +2153,26 @@  ovnact_put_opts_free(struct ovnact_put_opts *pdo)
     free_gen_options(pdo->options, pdo->n_options);
 }
 
+static void
+parse_DHCP6_SERVER_PKT(struct action_context *ctx)
+{
+    parse_nested_action(ctx, OVNACT_DHCP6_SERVER_PKT, "ip6");
+}
+
+static void
+format_DHCP6_SERVER_PKT(const struct ovnact_nest *nest, struct ds *s)
+{
+    format_nested_action(nest, "dhcp6_server_pkt", s);
+}
+
+static void
+encode_DHCP6_SERVER_PKT(const struct ovnact_nest *on,
+                        const struct ovnact_encode_params *ep,
+                        struct ofpbuf *ofpacts)
+{
+    encode_nested_actions(on, ep, ACTION_OPCODE_DHCP6_SERVER, ofpacts);
+}
+
 static void
 parse_SET_QUEUE(struct action_context *ctx)
 {
@@ -2912,6 +2932,8 @@  parse_action(struct action_context *ctx)
         parse_trigger_event(ctx, ovnact_put_TRIGGER_EVENT(ctx->ovnacts));
     } else if (lexer_match_id(ctx->lexer, "bind_vport")) {
         parse_bind_vport(ctx);
+    } else if (lexer_match_id(ctx->lexer, "dhcp6_server_pkt")) {
+        parse_DHCP6_SERVER_PKT(ctx);
     } else {
         lexer_syntax_error(ctx->lexer, "expecting action");
     }
diff --git a/lib/ovn-l7.h b/lib/ovn-l7.h
index c93def450..bcbc28148 100644
--- a/lib/ovn-l7.h
+++ b/lib/ovn-l7.h
@@ -174,8 +174,11 @@  struct dhcp_opt6_header {
 #define DHCPV6_OPT_SERVER_ID_CODE        2
 #define DHCPV6_OPT_IA_NA_CODE            3
 #define DHCPV6_OPT_IA_ADDR_CODE          5
+#define DHCPV6_OPT_STATUS_CODE           13
 #define DHCPV6_OPT_DNS_SERVER_CODE       23
 #define DHCPV6_OPT_DOMAIN_SEARCH_CODE    24
+#define DHCPV6_OPT_IA_PD                 25
+#define DHCPV6_OPT_IA_PREFIX             26
 
 #define DHCPV6_OPT_SERVER_ID \
     DHCP_OPTION("server_id", DHCPV6_OPT_SERVER_ID_CODE, "mac")
@@ -220,6 +223,22 @@  struct dhcpv6_opt_ia_na {
     ovs_be32 t2;
 });
 
+OVS_PACKED(
+struct dhcpv6_opt_ia_prefix {
+    struct dhcpv6_opt_header opt;
+    ovs_be32 plife_time;
+    ovs_be32 vlife_time;
+    uint8_t plen;
+    struct in6_addr ipv6;
+});
+
+OVS_PACKED(
+struct dhcpv6_opt_status {
+    struct dhcpv6_opt_header opt;
+    ovs_be16 status_code;
+    uint8_t msg[];
+});
+
 #define DHCPV6_DUID_LL      3
 #define DHCPV6_HW_TYPE_ETH  1
 
diff --git a/tests/ovn.at b/tests/ovn.at
index 22b272a60..dedfec5e1 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -2592,6 +2592,12 @@  bind_vport("xyzzy",;
 bind_vport("xyzzy", inport;
     Syntax error at `;' expecting `)'.
 
+# prefix delegation
+dhcp6_server_pkt{};
+    formats as dhcp6_server_pkt { drop; };
+    encodes as controller(userdata=00.00.00.12.00.00.00.00)
+    has prereqs ip6
+
 # Miscellaneous negative tests.
 ;
     Syntax error at `;'.
diff --git a/utilities/ovn-trace.c b/utilities/ovn-trace.c
index c95acb897..784a7fbb2 100644
--- a/utilities/ovn-trace.c
+++ b/utilities/ovn-trace.c
@@ -2216,6 +2216,8 @@  trace_actions(const struct ovnact *ovnacts, size_t ovnacts_len,
 
         case OVNACT_BIND_VPORT:
             break;
+        case OVNACT_DHCP6_SERVER_PKT:
+            break;
         }
     }
     ds_destroy(&s);