[PATCH net-next 2/2] net: geneve: enable local address bind for geneve sockets

[Richard Gobert <richardbgobert@gmail.com>]

This patch adds support for binding to a local address in geneve sockets.
It achieves this by adding a geneve_addr union to represent local address
to bind to, and copying it to udp_port_cfg in geneve_create_sock.

Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
---
 drivers/net/geneve.c               | 58 +++++++++++++++++++++++++++---
 include/net/geneve.h               |  6 ++++
 include/uapi/linux/if_link.h       |  2 ++
 tools/include/uapi/linux/if_link.h |  2 ++
 4 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 32c51c244153..d0b4cb0e7c51 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -57,6 +57,7 @@ struct geneve_config {
 	bool			ttl_inherit;
 	enum ifla_geneve_df	df;
 	bool			inner_proto_inherit;
+	union geneve_addr saddr;
 };
 
 /* Pseudo network device */
@@ -451,7 +452,8 @@ static int geneve_udp_encap_err_lookup(struct sock *sk, struct sk_buff *skb)
 }
 
 static struct socket *geneve_create_sock(struct net *net, bool ipv6,
-					 __be16 port, bool ipv6_rx_csum)
+					 __be16 port, bool ipv6_rx_csum,
+					 union geneve_addr *local_addr)
 {
 	struct socket *sock;
 	struct udp_port_cfg udp_conf;
@@ -463,9 +465,15 @@ static struct socket *geneve_create_sock(struct net *net, bool ipv6,
 		udp_conf.family = AF_INET6;
 		udp_conf.ipv6_v6only = 1;
 		udp_conf.use_udp6_rx_checksums = ipv6_rx_csum;
+		memcpy(&udp_conf.local_ip6,
+		       &local_addr->sin6.sin6_addr,
+		       sizeof(local_addr->sin6.sin6_addr));
 	} else {
 		udp_conf.family = AF_INET;
 		udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
+		memcpy(&udp_conf.local_ip,
+		       &local_addr->sin.sin_addr,
+		       sizeof(local_addr->sin.sin_addr));
 	}
 
 	udp_conf.local_udp_port = port;
@@ -572,7 +580,8 @@ static int geneve_gro_complete(struct sock *sk, struct sk_buff *skb,
 
 /* Create new listen socket if needed */
 static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
-						bool ipv6, bool ipv6_rx_csum)
+						bool ipv6, bool ipv6_rx_csum,
+						union geneve_addr *local_addr)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_sock *gs;
@@ -584,7 +593,7 @@ static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
 	if (!gs)
 		return ERR_PTR(-ENOMEM);
 
-	sock = geneve_create_sock(net, ipv6, port, ipv6_rx_csum);
+	sock = geneve_create_sock(net, ipv6, port, ipv6_rx_csum, local_addr);
 	if (IS_ERR(sock)) {
 		kfree(gs);
 		return ERR_CAST(sock);
@@ -672,7 +681,8 @@ static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
 	}
 
 	gs = geneve_socket_create(net, geneve->cfg.info.key.tp_dst, ipv6,
-				  geneve->cfg.use_udp6_rx_checksums);
+				  geneve->cfg.use_udp6_rx_checksums,
+				  &geneve->cfg.saddr);
 	if (IS_ERR(gs))
 		return PTR_ERR(gs);
 
@@ -1203,7 +1213,7 @@ static void geneve_setup(struct net_device *dev)
 }
 
 static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
-	[IFLA_GENEVE_UNSPEC]		= { .strict_start_type = IFLA_GENEVE_INNER_PROTO_INHERIT },
+	[IFLA_GENEVE_UNSPEC]		= { .strict_start_type = IFLA_GENEVE_LOCAL6 },
 	[IFLA_GENEVE_ID]		= { .type = NLA_U32 },
 	[IFLA_GENEVE_REMOTE]		= { .len = sizeof_field(struct iphdr, daddr) },
 	[IFLA_GENEVE_REMOTE6]		= { .len = sizeof(struct in6_addr) },
@@ -1218,6 +1228,8 @@ static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
 	[IFLA_GENEVE_TTL_INHERIT]	= { .type = NLA_U8 },
 	[IFLA_GENEVE_DF]		= { .type = NLA_U8 },
 	[IFLA_GENEVE_INNER_PROTO_INHERIT]	= { .type = NLA_FLAG },
+	[IFLA_GENEVE_LOCAL]	= { .len = sizeof_field(struct iphdr, saddr) },
+	[IFLA_GENEVE_LOCAL6]	= { .len = sizeof(struct in6_addr) },
 };
 
 static int geneve_validate(struct nlattr *tb[], struct nlattr *data[],
@@ -1544,6 +1556,31 @@ static int geneve_nl2info(struct nlattr *tb[], struct nlattr *data[],
 		cfg->inner_proto_inherit = true;
 	}
 
+	if (data[IFLA_GENEVE_LOCAL]) {
+		if (changelink && cfg->saddr.sa.sa_family != AF_INET) {
+			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_GENEVE_LOCAL], "New local address family does not match old");
+			return -EOPNOTSUPP;
+		}
+
+		cfg->saddr.sin.sin_addr.s_addr = nla_get_in_addr(data[IFLA_GENEVE_LOCAL]);
+		cfg->saddr.sa.sa_family = AF_INET;
+	}
+
+	if (data[IFLA_GENEVE_LOCAL6]) {
+		if (!IS_ENABLED(CONFIG_IPV6)) {
+			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_GENEVE_LOCAL6], "IPv6 support not enabled in the kernel");
+			return -EPFNOSUPPORT;
+		}
+
+		if (changelink && cfg->saddr.sa.sa_family != AF_INET6) {
+			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_GENEVE_LOCAL6], "New local address family does not match old");
+			return -EOPNOTSUPP;
+		}
+
+		cfg->saddr.sin6.sin6_addr = nla_get_in6_addr(data[IFLA_VXLAN_LOCAL6]);
+		cfg->saddr.sa.sa_family = AF_INET6;
+	}
+
 	return 0;
 change_notsup:
 	NL_SET_ERR_MSG_ATTR(extack, data[attrtype],
@@ -1724,6 +1761,7 @@ static size_t geneve_get_size(const struct net_device *dev)
 		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_RX */
 		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_TTL_INHERIT */
 		nla_total_size(0) +	 /* IFLA_GENEVE_INNER_PROTO_INHERIT */
+		nla_total_size(sizeof(struct in6_addr)) + /* IFLA_GENEVE_LOCAL{6} */
 		0;
 }
 
@@ -1745,6 +1783,11 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		if (nla_put_in_addr(skb, IFLA_GENEVE_REMOTE,
 				    info->key.u.ipv4.dst))
 			goto nla_put_failure;
+
+		if (nla_put_in_addr(skb, IFLA_GENEVE_LOCAL,
+				    info->key.u.ipv4.src))
+			goto nla_put_failure;
+
 		if (nla_put_u8(skb, IFLA_GENEVE_UDP_CSUM,
 			       !!(info->key.tun_flags & TUNNEL_CSUM)))
 			goto nla_put_failure;
@@ -1754,6 +1797,11 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		if (nla_put_in6_addr(skb, IFLA_GENEVE_REMOTE6,
 				     &info->key.u.ipv6.dst))
 			goto nla_put_failure;
+
+		if (nla_put_in6_addr(skb, IFLA_GENEVE_LOCAL6,
+				     &info->key.u.ipv6.src))
+			goto nla_put_failure;
+
 		if (nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
 			       !(info->key.tun_flags & TUNNEL_CSUM)))
 			goto nla_put_failure;
diff --git a/include/net/geneve.h b/include/net/geneve.h
index 5c96827a487e..8dcd7fff2c0f 100644
--- a/include/net/geneve.h
+++ b/include/net/geneve.h
@@ -68,6 +68,12 @@ static inline bool netif_is_geneve(const struct net_device *dev)
 	       !strcmp(dev->rtnl_link_ops->kind, "geneve");
 }
 
+union geneve_addr {
+	struct sockaddr_in sin;
+	struct sockaddr_in6 sin6;
+	struct sockaddr sa;
+};
+
 #ifdef CONFIG_INET
 struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 					u8 name_assign_type, u16 dst_port);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index ab9bcff96e4d..e4a0cdea734b 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -1419,6 +1419,8 @@ enum {
 	IFLA_GENEVE_TTL_INHERIT,
 	IFLA_GENEVE_DF,
 	IFLA_GENEVE_INNER_PROTO_INHERIT,
+	IFLA_GENEVE_LOCAL,
+	IFLA_GENEVE_LOCAL6,
 	__IFLA_GENEVE_MAX
 };
 #define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
diff --git a/tools/include/uapi/linux/if_link.h b/tools/include/uapi/linux/if_link.h
index a0aa05a28cf2..438bd867ec38 100644
--- a/tools/include/uapi/linux/if_link.h
+++ b/tools/include/uapi/linux/if_link.h
@@ -888,6 +888,8 @@ enum {
 	IFLA_GENEVE_TTL_INHERIT,
 	IFLA_GENEVE_DF,
 	IFLA_GENEVE_INNER_PROTO_INHERIT,
+	IFLA_GENEVE_LOCAL,
+	IFLA_GENEVE_LOCAL6,
 	__IFLA_GENEVE_MAX
 };
 #define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
-- 
2.36.1