From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 28 Jul 2021 05:49:46 +0200
Subject: [PATCH] driver_nl80211: rewrite neigh code to not depend on
 libnl3-route

Removes an unnecessary dependency and also makes the code smaller

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -16,9 +16,6 @@
 #include <net/if.h>
 #include <netlink/genl/genl.h>
 #include <netlink/genl/ctrl.h>
-#ifdef CONFIG_LIBNL3_ROUTE
-#include <netlink/route/neighbour.h>
-#endif /* CONFIG_LIBNL3_ROUTE */
 #include <linux/rtnetlink.h>
 #include <netpacket/packet.h>
 #include <linux/errqueue.h>
@@ -5783,26 +5780,29 @@ fail:
 
 static void rtnl_neigh_delete_fdb_entry(struct i802_bss *bss, const u8 *addr)
 {
-#ifdef CONFIG_LIBNL3_ROUTE
 	struct wpa_driver_nl80211_data *drv = bss->drv;
-	struct rtnl_neigh *rn;
-	struct nl_addr *nl_addr;
+	struct ndmsg nhdr = {
+		.ndm_state = NUD_PERMANENT,
+		.ndm_ifindex = bss->ifindex,
+		.ndm_family = AF_BRIDGE,
+	};
+	struct nl_msg *msg;
 	int err;
 
-	rn = rtnl_neigh_alloc();
-	if (!rn)
+	msg = nlmsg_alloc_simple(RTM_DELNEIGH, NLM_F_CREATE);
+	if (!msg)
 		return;
 
-	rtnl_neigh_set_family(rn, AF_BRIDGE);
-	rtnl_neigh_set_ifindex(rn, bss->ifindex);
-	nl_addr = nl_addr_build(AF_BRIDGE, (void *) addr, ETH_ALEN);
-	if (!nl_addr) {
-		rtnl_neigh_put(rn);
-		return;
-	}
-	rtnl_neigh_set_lladdr(rn, nl_addr);
+	if (nlmsg_append(msg, &nhdr, sizeof(nhdr), NLMSG_ALIGNTO) < 0)
+		goto errout;
+
+	if (nla_put(msg, NDA_LLADDR, ETH_ALEN, (void *)addr))
+		goto errout;
+
+	if (nl_send_auto_complete(drv->rtnl_sk, msg) < 0)
+		goto errout;
 
-	err = rtnl_neigh_delete(drv->rtnl_sk, rn, 0);
+	err = nl_wait_for_ack(drv->rtnl_sk);
 	if (err < 0) {
 		wpa_printf(MSG_DEBUG, "nl80211: bridge FDB entry delete for "
 			   MACSTR " ifindex=%d failed: %s", MAC2STR(addr),
@@ -5812,9 +5812,8 @@ static void rtnl_neigh_delete_fdb_entry(
 			   MACSTR, MAC2STR(addr));
 	}
 
-	nl_addr_put(nl_addr);
-	rtnl_neigh_put(rn);
-#endif /* CONFIG_LIBNL3_ROUTE */
+errout:
+	nlmsg_free(msg);
 }
 
 
@@ -8492,7 +8491,6 @@ static void *i802_init(struct hostapd_da
 	    (params->num_bridge == 0 || !params->bridge[0]))
 		add_ifidx(drv, br_ifindex, drv->ifindex);
 
-#ifdef CONFIG_LIBNL3_ROUTE
 	if (bss->added_if_into_bridge || bss->already_in_bridge) {
 		int err;
 
@@ -8509,7 +8507,6 @@ static void *i802_init(struct hostapd_da
 			goto failed;
 		}
 	}
-#endif /* CONFIG_LIBNL3_ROUTE */
 
 	if (drv->capa.flags2 & WPA_DRIVER_FLAGS2_CONTROL_PORT_RX) {
 		wpa_printf(MSG_DEBUG,
@@ -11883,13 +11880,14 @@ static int wpa_driver_br_add_ip_neigh(vo
 				      const u8 *ipaddr, int prefixlen,
 				      const u8 *addr)
 {
-#ifdef CONFIG_LIBNL3_ROUTE
 	struct i802_bss *bss = priv;
 	struct wpa_driver_nl80211_data *drv = bss->drv;
-	struct rtnl_neigh *rn;
-	struct nl_addr *nl_ipaddr = NULL;
-	struct nl_addr *nl_lladdr = NULL;
-	int family, addrsize;
+	struct ndmsg nhdr = {
+		.ndm_state = NUD_PERMANENT,
+		.ndm_ifindex = bss->br_ifindex,
+	};
+	struct nl_msg *msg;
+	int addrsize;
 	int res;
 
 	if (!ipaddr || prefixlen == 0 || !addr)
@@ -11908,85 +11906,66 @@ static int wpa_driver_br_add_ip_neigh(vo
 	}
 
 	if (version == 4) {
-		family = AF_INET;
+		nhdr.ndm_family = AF_INET;
 		addrsize = 4;
 	} else if (version == 6) {
-		family = AF_INET6;
+		nhdr.ndm_family = AF_INET6;
 		addrsize = 16;
 	} else {
 		return -EINVAL;
 	}
 
-	rn = rtnl_neigh_alloc();
-	if (rn == NULL)
+	msg = nlmsg_alloc_simple(RTM_NEWNEIGH, NLM_F_CREATE);
+	if (!msg)
 		return -ENOMEM;
 
-	/* set the destination ip address for neigh */
-	nl_ipaddr = nl_addr_build(family, (void *) ipaddr, addrsize);
-	if (nl_ipaddr == NULL) {
-		wpa_printf(MSG_DEBUG, "nl80211: nl_ipaddr build failed");
-		res = -ENOMEM;
+	res = -ENOMEM;
+	if (nlmsg_append(msg, &nhdr, sizeof(nhdr), NLMSG_ALIGNTO) < 0)
 		goto errout;
-	}
-	nl_addr_set_prefixlen(nl_ipaddr, prefixlen);
-	res = rtnl_neigh_set_dst(rn, nl_ipaddr);
-	if (res) {
-		wpa_printf(MSG_DEBUG,
-			   "nl80211: neigh set destination addr failed");
+
+	if (nla_put(msg, NDA_DST, addrsize, (void *)ipaddr))
 		goto errout;
-	}
 
-	/* set the corresponding lladdr for neigh */
-	nl_lladdr = nl_addr_build(AF_BRIDGE, (u8 *) addr, ETH_ALEN);
-	if (nl_lladdr == NULL) {
-		wpa_printf(MSG_DEBUG, "nl80211: neigh set lladdr failed");
-		res = -ENOMEM;
+	if (nla_put(msg, NDA_LLADDR, ETH_ALEN, (void *)addr))
 		goto errout;
-	}
-	rtnl_neigh_set_lladdr(rn, nl_lladdr);
 
-	rtnl_neigh_set_ifindex(rn, bss->br_ifindex);
-	rtnl_neigh_set_state(rn, NUD_PERMANENT);
+	res = nl_send_auto_complete(drv->rtnl_sk, msg);
+	if (res < 0)
+		goto errout;
 
-	res = rtnl_neigh_add(drv->rtnl_sk, rn, NLM_F_CREATE);
+	res = nl_wait_for_ack(drv->rtnl_sk);
 	if (res) {
 		wpa_printf(MSG_DEBUG,
 			   "nl80211: Adding bridge ip neigh failed: %s",
 			   nl_geterror(res));
 	}
 errout:
-	if (nl_lladdr)
-		nl_addr_put(nl_lladdr);
-	if (nl_ipaddr)
-		nl_addr_put(nl_ipaddr);
-	if (rn)
-		rtnl_neigh_put(rn);
+	nlmsg_free(msg);
 	return res;
-#else /* CONFIG_LIBNL3_ROUTE */
-	return -1;
-#endif /* CONFIG_LIBNL3_ROUTE */
 }
 
 
 static int wpa_driver_br_delete_ip_neigh(void *priv, u8 version,
 					 const u8 *ipaddr)
 {
-#ifdef CONFIG_LIBNL3_ROUTE
 	struct i802_bss *bss = priv;
 	struct wpa_driver_nl80211_data *drv = bss->drv;
-	struct rtnl_neigh *rn;
-	struct nl_addr *nl_ipaddr;
-	int family, addrsize;
+	struct ndmsg nhdr = {
+		.ndm_state = NUD_PERMANENT,
+		.ndm_ifindex = bss->br_ifindex,
+	};
+	struct nl_msg *msg;
+	int addrsize;
 	int res;
 
 	if (!ipaddr)
 		return -EINVAL;
 
 	if (version == 4) {
-		family = AF_INET;
+		nhdr.ndm_family = AF_INET;
 		addrsize = 4;
 	} else if (version == 6) {
-		family = AF_INET6;
+		nhdr.ndm_family = AF_INET6;
 		addrsize = 16;
 	} else {
 		return -EINVAL;
@@ -12004,41 +11983,30 @@ static int wpa_driver_br_delete_ip_neigh
 		return -1;
 	}
 
-	rn = rtnl_neigh_alloc();
-	if (rn == NULL)
+	msg = nlmsg_alloc_simple(RTM_DELNEIGH, NLM_F_CREATE);
+	if (!msg)
 		return -ENOMEM;
 
-	/* set the destination ip address for neigh */
-	nl_ipaddr = nl_addr_build(family, (void *) ipaddr, addrsize);
-	if (nl_ipaddr == NULL) {
-		wpa_printf(MSG_DEBUG, "nl80211: nl_ipaddr build failed");
-		res = -ENOMEM;
+	res = -ENOMEM;
+	if (nlmsg_append(msg, &nhdr, sizeof(nhdr), NLMSG_ALIGNTO) < 0)
 		goto errout;
-	}
-	res = rtnl_neigh_set_dst(rn, nl_ipaddr);
-	if (res) {
-		wpa_printf(MSG_DEBUG,
-			   "nl80211: neigh set destination addr failed");
+
+	if (nla_put(msg, NDA_DST, addrsize, (void *)ipaddr))
 		goto errout;
-	}
 
-	rtnl_neigh_set_ifindex(rn, bss->br_ifindex);
+	res = nl_send_auto_complete(drv->rtnl_sk, msg);
+	if (res < 0)
+		goto errout;
 
-	res = rtnl_neigh_delete(drv->rtnl_sk, rn, 0);
+	res = nl_wait_for_ack(drv->rtnl_sk);
 	if (res) {
 		wpa_printf(MSG_DEBUG,
 			   "nl80211: Deleting bridge ip neigh failed: %s",
 			   nl_geterror(res));
 	}
 errout:
-	if (nl_ipaddr)
-		nl_addr_put(nl_ipaddr);
-	if (rn)
-		rtnl_neigh_put(rn);
+	nlmsg_free(msg);
 	return res;
-#else /* CONFIG_LIBNL3_ROUTE */
-	return -1;
-#endif /* CONFIG_LIBNL3_ROUTE */
 }