1 files changed, 135 insertions, 124 deletions

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index ebb381c3f1b9..def78eebca4c 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/*
- * L2TP netlink layer, for management
+/* L2TP netlink layer, for management
  *
  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
  *
@@ -27,7 +26,6 @@
 
 #include "l2tp_core.h"
 
-
 static struct genl_family l2tp_nl_family;
 
 static const struct genl_multicast_group l2tp_multicast_group[] = {
@@ -157,81 +155,82 @@ static int l2tp_session_notify(struct genl_family *family,
 	return ret;
 }
 
+static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg)
+{
+	if (attrs[L2TP_ATTR_UDP_SPORT])
+		cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);
+	if (attrs[L2TP_ATTR_UDP_DPORT])
+		cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);
+	cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);
+
+	/* Must have either AF_INET or AF_INET6 address for source and destination */
+#if IS_ENABLED(CONFIG_IPV6)
+	if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {
+		cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);
+		cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);
+		cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
+		cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
+		return 0;
+	}
+#endif
+	if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {
+		cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);
+		cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);
+		return 0;
+	}
+	return -EINVAL;
+}
+
 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 {
 	u32 tunnel_id;
 	u32 peer_tunnel_id;
 	int proto_version;
-	int fd;
+	int fd = -1;
 	int ret = 0;
 	struct l2tp_tunnel_cfg cfg = { 0, };
 	struct l2tp_tunnel *tunnel;
 	struct net *net = genl_info_net(info);
+	struct nlattr **attrs = info->attrs;
 
-	if (!info->attrs[L2TP_ATTR_CONN_ID]) {
+	if (!attrs[L2TP_ATTR_CONN_ID]) {
 		ret = -EINVAL;
 		goto out;
 	}
-	tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
+	tunnel_id = nla_get_u32(attrs[L2TP_ATTR_CONN_ID]);
 
-	if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
+	if (!attrs[L2TP_ATTR_PEER_CONN_ID]) {
 		ret = -EINVAL;
 		goto out;
 	}
-	peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
+	peer_tunnel_id = nla_get_u32(attrs[L2TP_ATTR_PEER_CONN_ID]);
 
-	if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
+	if (!attrs[L2TP_ATTR_PROTO_VERSION]) {
 		ret = -EINVAL;
 		goto out;
 	}
-	proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
+	proto_version = nla_get_u8(attrs[L2TP_ATTR_PROTO_VERSION]);
 
-	if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
+	if (!attrs[L2TP_ATTR_ENCAP_TYPE]) {
 		ret = -EINVAL;
 		goto out;
 	}
-	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
-
-	fd = -1;
-	if (info->attrs[L2TP_ATTR_FD]) {
-		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
+	cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);
+
+	/* Managed tunnels take the tunnel socket from userspace.
+	 * Unmanaged tunnels must call out the source and destination addresses
+	 * for the kernel to create the tunnel socket itself.
+	 */
+	if (attrs[L2TP_ATTR_FD]) {
+		fd = nla_get_u32(attrs[L2TP_ATTR_FD]);
 	} else {
-#if IS_ENABLED(CONFIG_IPV6)
-		if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
-		    info->attrs[L2TP_ATTR_IP6_DADDR]) {
-			cfg.local_ip6 = nla_data(
-				info->attrs[L2TP_ATTR_IP6_SADDR]);
-			cfg.peer_ip6 = nla_data(
-				info->attrs[L2TP_ATTR_IP6_DADDR]);
-		} else
-#endif
-		if (info->attrs[L2TP_ATTR_IP_SADDR] &&
-		    info->attrs[L2TP_ATTR_IP_DADDR]) {
-			cfg.local_ip.s_addr = nla_get_in_addr(
-				info->attrs[L2TP_ATTR_IP_SADDR]);
-			cfg.peer_ip.s_addr = nla_get_in_addr(
-				info->attrs[L2TP_ATTR_IP_DADDR]);
-		} else {
-			ret = -EINVAL;
+		ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg);
+		if (ret < 0)
 			goto out;
-		}
-		if (info->attrs[L2TP_ATTR_UDP_SPORT])
-			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
-		if (info->attrs[L2TP_ATTR_UDP_DPORT])
-			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
-		cfg.use_udp_checksums = nla_get_flag(
-			info->attrs[L2TP_ATTR_UDP_CSUM]);
-
-#if IS_ENABLED(CONFIG_IPV6)
-		cfg.udp6_zero_tx_checksums = nla_get_flag(
-			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
-		cfg.udp6_zero_rx_checksums = nla_get_flag(
-			info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
-#endif
 	}
 
-	if (info->attrs[L2TP_ATTR_DEBUG])
-		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
+	if (attrs[L2TP_ATTR_DEBUG])
+		cfg.debug = nla_get_u32(attrs[L2TP_ATTR_DEBUG]);
 
 	ret = -EINVAL;
 	switch (cfg.encap) {
@@ -320,16 +319,79 @@ out:
 	return ret;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
+static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk,
+				     enum l2tp_encap_type encap)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ipv6_pinfo *np = inet6_sk(sk);
+
+	switch (encap) {
+	case L2TP_ENCAPTYPE_UDP:
+		if (udp_get_no_check6_tx(sk) &&
+		    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
+			return -1;
+		if (udp_get_no_check6_rx(sk) &&
+		    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
+			return -1;
+		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
+		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
+			return -1;
+		fallthrough;
+	case L2TP_ENCAPTYPE_IP:
+		if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) ||
+		    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr))
+			return -1;
+		break;
+	}
+	return 0;
+}
+#endif
+
+static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk,
+				     enum l2tp_encap_type encap)
+{
+	struct inet_sock *inet = inet_sk(sk);
+
+	switch (encap) {
+	case L2TP_ENCAPTYPE_UDP:
+		if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) ||
+		    nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
+		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
+			return -1;
+		fallthrough;
+	case L2TP_ENCAPTYPE_IP:
+		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
+		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
+			return -1;
+		break;
+	}
+
+	return 0;
+}
+
+/* Append attributes for the tunnel address, handling the different attribute types
+ * used for different tunnel encapsulation and AF_INET v.s. AF_INET6.
+ */
+static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel)
+{
+	struct sock *sk = tunnel->sock;
+
+	if (!sk)
+		return 0;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == AF_INET6)
+		return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap);
+#endif
+	return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap);
+}
+
 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 			       struct l2tp_tunnel *tunnel, u8 cmd)
 {
 	void *hdr;
 	struct nlattr *nest;
-	struct sock *sk = NULL;
-	struct inet_sock *inet;
-#if IS_ENABLED(CONFIG_IPV6)
-	struct ipv6_pinfo *np = NULL;
-#endif
 
 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 	if (!hdr)
@@ -343,7 +405,7 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
 		goto nla_put_failure;
 
 	nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
-	if (nest == NULL)
+	if (!nest)
 		goto nla_put_failure;
 
 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
@@ -373,58 +435,9 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
 		goto nla_put_failure;
 	nla_nest_end(skb, nest);
 
-	sk = tunnel->sock;
-	if (!sk)
-		goto out;
-
-#if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == AF_INET6)
-		np = inet6_sk(sk);
-#endif
-
-	inet = inet_sk(sk);
-
-	switch (tunnel->encap) {
-	case L2TP_ENCAPTYPE_UDP:
-		switch (sk->sk_family) {
-		case AF_INET:
-			if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
-				goto nla_put_failure;
-			break;
-#if IS_ENABLED(CONFIG_IPV6)
-		case AF_INET6:
-			if (udp_get_no_check6_tx(sk) &&
-			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
-				goto nla_put_failure;
-			if (udp_get_no_check6_rx(sk) &&
-			    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
-				goto nla_put_failure;
-			break;
-#endif
-		}
-		if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
-		    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
-			goto nla_put_failure;
-		/* fall through  */
-	case L2TP_ENCAPTYPE_IP:
-#if IS_ENABLED(CONFIG_IPV6)
-		if (np) {
-			if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
-					     &np->saddr) ||
-			    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
-					     &sk->sk_v6_daddr))
-				goto nla_put_failure;
-		} else
-#endif
-		if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
-				    inet->inet_saddr) ||
-		    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
-				    inet->inet_daddr))
-			goto nla_put_failure;
-		break;
-	}
+	if (l2tp_nl_tunnel_send_addr(skb, tunnel))
+		goto nla_put_failure;
 
-out:
 	genlmsg_end(skb, hdr);
 	return 0;
 
@@ -485,7 +498,7 @@ static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback
 
 	for (;;) {
 		tunnel = l2tp_tunnel_get_nth(net, ti);
-		if (tunnel == NULL)
+		if (!tunnel)
 			goto out;
 
 		if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
@@ -570,6 +583,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 
 		if (info->attrs[L2TP_ATTR_COOKIE]) {
 			u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
+
 			if (len > 8) {
 				ret = -EINVAL;
 				goto out_tunnel;
@@ -579,6 +593,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 		}
 		if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 			u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
+
 			if (len > 8) {
 				ret = -EINVAL;
 				goto out_tunnel;
@@ -606,14 +621,13 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 		cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 
 #ifdef CONFIG_MODULES
-	if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
+	if (!l2tp_nl_cmd_ops[cfg.pw_type]) {
 		genl_unlock();
 		request_module("net-l2tp-type-%u", cfg.pw_type);
 		genl_lock();
 	}
 #endif
-	if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
-	    (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
+	if (!l2tp_nl_cmd_ops[cfg.pw_type] || !l2tp_nl_cmd_ops[cfg.pw_type]->session_create) {
 		ret = -EPROTONOSUPPORT;
 		goto out_tunnel;
 	}
@@ -645,7 +659,7 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf
 	u16 pw_type;
 
 	session = l2tp_nl_session_get(info);
-	if (session == NULL) {
+	if (!session) {
 		ret = -ENODEV;
 		goto out;
 	}
@@ -656,7 +670,7 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf
 	pw_type = session->pwtype;
 	if (pw_type < __L2TP_PWTYPE_MAX)
 		if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
-			ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
+			l2tp_nl_cmd_ops[pw_type]->session_delete(session);
 
 	l2tp_session_dec_refcount(session);
 
@@ -670,7 +684,7 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
 	struct l2tp_session *session;
 
 	session = l2tp_nl_session_get(info);
-	if (session == NULL) {
+	if (!session) {
 		ret = -ENODEV;
 		goto out;
 	}
@@ -715,8 +729,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 	if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
-	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
-			session->peer_session_id) ||
+	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype))
 		goto nla_put_failure;
@@ -724,11 +737,9 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 	if ((session->ifname[0] &&
 	     nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 	    (session->cookie_len &&
-	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
-		     &session->cookie[0])) ||
+	     nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, session->cookie)) ||
 	    (session->peer_cookie_len &&
-	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
-		     &session->peer_cookie[0])) ||
+	     nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, session->peer_cookie)) ||
 	    nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 	    nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 	    nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
@@ -740,7 +751,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 		goto nla_put_failure;
 
 	nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
-	if (nest == NULL)
+	if (!nest)
 		goto nla_put_failure;
 
 	if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
@@ -785,7 +796,7 @@ static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 	int ret;
 
 	session = l2tp_nl_session_get(info);
-	if (session == NULL) {
+	if (!session) {
 		ret = -ENODEV;
 		goto err;
 	}
@@ -824,14 +835,14 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
 	int si = cb->args[1];
 
 	for (;;) {
-		if (tunnel == NULL) {
+		if (!tunnel) {
 			tunnel = l2tp_tunnel_get_nth(net, ti);
-			if (tunnel == NULL)
+			if (!tunnel)
 				goto out;
 		}
 
 		session = l2tp_session_get_nth(tunnel, si);
-		if (session == NULL) {
+		if (!session) {
 			ti++;
 			l2tp_tunnel_dec_refcount(tunnel);
 			tunnel = NULL;