mctp-netlink: Add helpers to add or remove neighbours

Mirror the existing mctp_nl_route_{add,del} helpers.

Signed-off-by: Khang Nguyen <[email protected]>

Author: Khang Nguyen

src/mctp-netlink.c

@@ -1163,3 +1163,75 @@ int mctp_nl_route_del(struct mctp_nl *nl, uint8_t eid, const char* ifname)
 	return mctp_nl_send(nl, &msg.nh);
 }
 
+/* Common parts of RTM_NEWNEIGH and RTM_DELNEIGH */
+struct mctp_ndalter_msg {
+	struct nlmsghdr nh;
+	struct ndmsg ndmsg;
+	uint8_t rta_buff[RTA_SPACE(1) + RTA_SPACE(MAX_ADDR_LEN)];
+};
+
+static int fill_ndalter_args(struct mctp_nl *nl, struct mctp_ndalter_msg *msg,
+			     struct rtattr **prta, size_t *prta_len,
+			     mctp_eid_t eid, const char *ifname)
+{
+	struct rtattr *rta;
+	size_t rta_len;
+	int ifindex;
+
+	ifindex = mctp_nl_ifindex_byname(nl, ifname);
+	if (!ifindex) {
+		warnx("invalid device %s", ifname);
+		return -1;
+	}
+
+	msg->nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+	msg->ndmsg.ndm_ifindex = ifindex;
+	msg->ndmsg.ndm_family = AF_MCTP;
+	msg->nh.nlmsg_len = NLMSG_LENGTH(sizeof(msg->ndmsg));
+
+	rta_len = sizeof(msg->rta_buff);
+	rta = (void *)msg->rta_buff;
+
+	msg->nh.nlmsg_len += mctp_put_rtnlmsg_attr(&rta, &rta_len, NDA_DST,
+						   &eid, sizeof(eid));
+
+	if (prta)
+		*prta = rta;
+	if (prta_len)
+		*prta_len = rta_len;
+
+	return 0;
+}
+
+int mctp_nl_neigh_add(struct mctp_nl *nl, uint8_t eid, const char *ifname,
+		      uint8_t *haddr, uint8_t halen)
+{
+	struct mctp_ndalter_msg msg;
+	struct rtattr *rta;
+	size_t rta_len;
+	int rc;
+
+	rc = fill_ndalter_args(nl, &msg, &rta, &rta_len, eid, ifname);
+	if (rc) {
+		return rc;
+	}
+	msg.nh.nlmsg_type = RTM_NEWNEIGH;
+	msg.nh.nlmsg_len +=
+		mctp_put_rtnlmsg_attr(&rta, &rta_len, NDA_LLADDR, haddr, halen);
+
+	return mctp_nl_send(nl, &msg.nh);
+}
+
+int mctp_nl_neigh_del(struct mctp_nl *nl, uint8_t eid, const char *ifname)
+{
+	struct mctp_ndalter_msg msg;
+	int rc;
+
+	rc = fill_ndalter_args(nl, &msg, NULL, NULL, eid, ifname);
+	if (rc) {
+		return rc;
+	}
+	msg.nh.nlmsg_type = RTM_DELNEIGH;
+
+	return mctp_nl_send(nl, &msg.nh);
+}

src/mctp-netlink.h

@@ -74,6 +74,11 @@ int mctp_nl_route_add(struct mctp_nl *nl, uint8_t eid, const char* ifname,
 		uint32_t mtu);
 int mctp_nl_route_del(struct mctp_nl *nl, uint8_t eid, const char* ifname);
 
+/* MCTP neigh helper */
+int mctp_nl_neigh_add(struct mctp_nl *nl, uint8_t eid, const char *ifname,
+		      uint8_t *haddr, uint8_t halen);
+int mctp_nl_neigh_del(struct mctp_nl *nl, uint8_t eid, const char *ifname);
+
 /* Helpers */
 
 void* mctp_get_rtnlmsg_attr(int rta_type, struct rtattr *rta, size_t len,

src/mctpd.c

@@ -2033,26 +2033,30 @@ static int query_peer_properties(peer *peer)
 	return rc;
 }
 
+// type is RTM_NEWNEIGH or RTM_DELNEIGH
 static int peer_neigh_update(peer *peer, uint16_t type)
 {
-	struct {
-		struct nlmsghdr		nh;
-		struct ndmsg		ndmsg;
-		uint8_t			rta_buff[RTA_SPACE(1) + RTA_SPACE(MAX_ADDR_LEN)];
-	} msg = {0};
-	size_t rta_len = sizeof(msg.rta_buff);
-	struct rtattr *rta = (void*)msg.rta_buff;
-
-	msg.nh.nlmsg_type = type;
-	msg.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
-	msg.ndmsg.ndm_ifindex = peer->phys.ifindex;
-	msg.ndmsg.ndm_family = AF_MCTP;
-	msg.nh.nlmsg_len = NLMSG_LENGTH(sizeof(msg.ndmsg));
-	msg.nh.nlmsg_len += mctp_put_rtnlmsg_attr(&rta, &rta_len,
-		NDA_DST, &peer->eid, sizeof(peer->eid));
-	msg.nh.nlmsg_len += mctp_put_rtnlmsg_attr(&rta, &rta_len,
-		NDA_LLADDR, peer->phys.hwaddr, peer->phys.hwaddr_len);
-	return mctp_nl_send(peer->ctx->nl_query, &msg.nh);
+	const char *link;
+
+	link = mctp_nl_if_byindex(peer->ctx->nl_query, peer->phys.ifindex);
+	if (!link) {
+		warnx("BUG %s: Unknown ifindex %d", __func__,
+		      peer->phys.ifindex);
+		return -ENODEV;
+	}
+
+	if (type == RTM_NEWNEIGH) {
+		return mctp_nl_neigh_add(peer->ctx->nl_query, peer->eid, link,
+					 peer->phys.hwaddr,
+					 peer->phys.hwaddr_len);
+	} else if (type == RTM_DELNEIGH) {
+		return mctp_nl_neigh_del(peer->ctx->nl_query, peer->eid, link,
+					 peer->phys.hwaddr,
+					 peer->phys.hwaddr_len);
+	}
+
+	warnx("BUG %s: bad type %d", __func__, type);
+	return -EPROTO;
 }
 
 // type is RTM_NEWROUTE or RTM_DELROUTE