diff mbox series

[RFC,net-next,v5,1/6] gtp: Allow to create GTP device without FDs

Message ID 20220211175500.7805-1-marcin.szycik@linux.intel.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ice: GTP support in switchdev | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 4867 this patch: 4867
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 822 this patch: 822
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5024 this patch: 5024
netdev/checkpatch warning CHECK: Comparison to NULL could be written "!gtp->addr_hash" CHECK: Comparison to NULL could be written "!gtp->tid_hash"
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Marcin Szycik Feb. 11, 2022, 5:55 p.m. UTC 
From: Wojciech Drewek <wojciech.drewek@intel.com>

Currently, when the user wants to create GTP device, he has to
provide file handles to the sockets created in userspace (IFLA_GTP_FD0,
IFLA_GTP_FD1). This behaviour is not ideal, considering the option of
adding support for GTP device creation through ip link. Ip link
application is not a good place to create such sockets.

This patch allows to create GTP device without providing
IFLA_GTP_FD0 and IFLA_GTP_FD1 arguments. If the user sets
IFLA_GTP_CREATE_SOCKETS attribute, then GTP module takes care
of creating UDP sockets by itself. Sockets are created with the
commonly known UDP ports used for GTP protocol (GTP0_PORT and
GTP1U_PORT). In this case we don't have to provide encap_destroy
because no extra deinitialization is needed, everything is covered
by udp_tunnel_sock_release.

Note: GTP instance created with only this change applied, does
not handle GTP Echo Requests. This is implemented in the following
patch.

Besides that, small refactor was done, functions used in gtp_newlink
were moved above it. Handling of IFLA_GTP_ROLE attribute was moved
to gtp_newlink.

Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
---
v4: use ntohs when creating UDP socket
v5: IFLA_GTP_CREATE_SOCKETS introduced, gtp_newlink refactor
---
 drivers/net/gtp.c            | 306 +++++++++++++++++++++--------------
 include/uapi/linux/if_link.h |   1 +
 2 files changed, 186 insertions(+), 121 deletions(-)

Comments

Harald Welte Feb. 12, 2022, 8:15 a.m. UTC | #1 
Hi Marcin,

I'm sorry if you think this is too much nit-picking, but moving
around functions and removing forward declarations is making it
unneccessarily hard to read the generated diff:

Now it's not possible to see which bits of the code you really changed,
as entire functions have moved position within the file.

On Fri, Feb 11, 2022 at 06:55:00PM +0100, Marcin Szycik wrote:
> -static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
> -static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
> +static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
> +{
> +	int i;
> +
> +	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
> +				       GFP_KERNEL | __GFP_NOWARN);
> +	if (gtp->addr_hash == NULL)

...

I would appreciate if you could do any re-ordering of functions in a
separate, marked "cosmetic" commit, so we can see the actual changes you
make to the code in one patch, and the re-arranging in another.

Thanks!
diff mbox series

Patch

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 24e5c54d06c1..29978c5e37e8 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -66,8 +66,10 @@  struct gtp_dev {
 
 	struct sock		*sk0;
 	struct sock		*sk1u;
+	u8			sk_created;
 
 	struct net_device	*dev;
+	struct net		*net;
 
 	unsigned int		role;
 	unsigned int		hash_size;
@@ -320,8 +322,16 @@  static void gtp_encap_disable_sock(struct sock *sk)
 
 static void gtp_encap_disable(struct gtp_dev *gtp)
 {
-	gtp_encap_disable_sock(gtp->sk0);
-	gtp_encap_disable_sock(gtp->sk1u);
+	if (gtp->sk_created) {
+		udp_tunnel_sock_release(gtp->sk0->sk_socket);
+		udp_tunnel_sock_release(gtp->sk1u->sk_socket);
+		gtp->sk_created = false;
+		gtp->sk0 = NULL;
+		gtp->sk1u = NULL;
+	} else {
+		gtp_encap_disable_sock(gtp->sk0);
+		gtp_encap_disable_sock(gtp->sk1u);
+	}
 }
 
 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
@@ -645,8 +655,164 @@  static void gtp_link_setup(struct net_device *dev)
 	dev->needed_headroom	= LL_MAX_HEADER + max_gtp_header_len;
 }
 
-static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
-static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
+static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
+{
+	int i;
+
+	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
+				       GFP_KERNEL | __GFP_NOWARN);
+	if (gtp->addr_hash == NULL)
+		return -ENOMEM;
+
+	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
+				      GFP_KERNEL | __GFP_NOWARN);
+	if (gtp->tid_hash == NULL)
+		goto err1;
+
+	gtp->hash_size = hsize;
+
+	for (i = 0; i < hsize; i++) {
+		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
+		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
+	}
+	return 0;
+err1:
+	kfree(gtp->addr_hash);
+	return -ENOMEM;
+}
+
+static struct sock *gtp_encap_enable_socket(int fd, int type,
+					    struct gtp_dev *gtp)
+{
+	struct udp_tunnel_sock_cfg tuncfg = {NULL};
+	struct socket *sock;
+	struct sock *sk;
+	int err;
+
+	pr_debug("enable gtp on %d, %d\n", fd, type);
+
+	sock = sockfd_lookup(fd, &err);
+	if (!sock) {
+		pr_debug("gtp socket fd=%d not found\n", fd);
+		return NULL;
+	}
+
+	sk = sock->sk;
+	if (sk->sk_protocol != IPPROTO_UDP ||
+	    sk->sk_type != SOCK_DGRAM ||
+	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
+		pr_debug("socket fd=%d not UDP\n", fd);
+		sk = ERR_PTR(-EINVAL);
+		goto out_sock;
+	}
+
+	lock_sock(sk);
+	if (sk->sk_user_data) {
+		sk = ERR_PTR(-EBUSY);
+		goto out_rel_sock;
+	}
+
+	sock_hold(sk);
+
+	tuncfg.sk_user_data = gtp;
+	tuncfg.encap_type = type;
+	tuncfg.encap_rcv = gtp_encap_recv;
+	tuncfg.encap_destroy = gtp_encap_destroy;
+
+	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
+
+out_rel_sock:
+	release_sock(sock->sk);
+out_sock:
+	sockfd_put(sock);
+	return sk;
+}
+
+static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
+{
+	struct sock *sk1u = NULL;
+	struct sock *sk0 = NULL;
+
+	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
+		return -EINVAL;
+
+	if (data[IFLA_GTP_FD0]) {
+		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
+
+		sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
+		if (IS_ERR(sk0))
+			return PTR_ERR(sk0);
+	}
+
+	if (data[IFLA_GTP_FD1]) {
+		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
+
+		sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
+		if (IS_ERR(sk1u)) {
+			gtp_encap_disable_sock(sk0);
+			return PTR_ERR(sk1u);
+		}
+	}
+
+	gtp->sk0 = sk0;
+	gtp->sk1u = sk1u;
+
+	return 0;
+}
+
+static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp)
+{
+	struct udp_tunnel_sock_cfg tuncfg = {};
+	struct udp_port_cfg udp_conf = {
+		.local_ip.s_addr	= htonl(INADDR_ANY),
+		.family			= AF_INET,
+	};
+	struct net *net = gtp->net;
+	struct socket *sock;
+	int err;
+
+	if (type == UDP_ENCAP_GTP0)
+		udp_conf.local_udp_port = htons(GTP0_PORT);
+	else if (type == UDP_ENCAP_GTP1U)
+		udp_conf.local_udp_port = htons(GTP1U_PORT);
+	else
+		return ERR_PTR(-EINVAL);
+
+	err = udp_sock_create(net, &udp_conf, &sock);
+	if (err)
+		return ERR_PTR(err);
+
+	tuncfg.sk_user_data = gtp;
+	tuncfg.encap_type = type;
+	tuncfg.encap_rcv = gtp_encap_recv;
+	tuncfg.encap_destroy = NULL;
+
+	setup_udp_tunnel_sock(net, sock, &tuncfg);
+
+	return sock->sk;
+}
+
+static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[])
+{
+	struct sock *sk1u = NULL;
+	struct sock *sk0 = NULL;
+
+	sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp);
+	if (IS_ERR(sk0))
+		return PTR_ERR(sk0);
+
+	sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp);
+	if (IS_ERR(sk1u)) {
+		udp_tunnel_sock_release(sk0->sk_socket);
+		return PTR_ERR(sk1u);
+	}
+
+	gtp->sk_created = true;
+	gtp->sk0 = sk0;
+	gtp->sk1u = sk1u;
+
+	return 0;
+}
 
 static void gtp_destructor(struct net_device *dev)
 {
@@ -660,13 +826,11 @@  static int gtp_newlink(struct net *src_net, struct net_device *dev,
 		       struct nlattr *tb[], struct nlattr *data[],
 		       struct netlink_ext_ack *extack)
 {
+	unsigned int role = GTP_ROLE_GGSN;
 	struct gtp_dev *gtp;
 	struct gtp_net *gn;
 	int hashsize, err;
 
-	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
-		return -EINVAL;
-
 	gtp = netdev_priv(dev);
 
 	if (!data[IFLA_GTP_PDP_HASHSIZE]) {
@@ -677,11 +841,23 @@  static int gtp_newlink(struct net *src_net, struct net_device *dev,
 			hashsize = 1024;
 	}
 
+	if (data[IFLA_GTP_ROLE]) {
+		role = nla_get_u32(data[IFLA_GTP_ROLE]);
+		if (role > GTP_ROLE_SGSN)
+			return -EINVAL;
+	}
+	gtp->role = role;
+
+	gtp->net = src_net;
+
 	err = gtp_hashtable_new(gtp, hashsize);
 	if (err < 0)
 		return err;
 
-	err = gtp_encap_enable(gtp, data);
+	if (data[IFLA_GTP_CREATE_SOCKETS])
+		err = gtp_create_sockets(gtp, data);
+	else
+		err = gtp_encap_enable(gtp, data);
 	if (err < 0)
 		goto out_hashtable;
 
@@ -726,6 +902,7 @@  static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
 	[IFLA_GTP_ROLE]			= { .type = NLA_U32 },
+	[IFLA_GTP_CREATE_SOCKETS]	= { .type = NLA_U8 },
 };
 
 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
@@ -771,119 +948,6 @@  static struct rtnl_link_ops gtp_link_ops __read_mostly = {
 	.fill_info	= gtp_fill_info,
 };
 
-static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
-{
-	int i;
-
-	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
-				       GFP_KERNEL | __GFP_NOWARN);
-	if (gtp->addr_hash == NULL)
-		return -ENOMEM;
-
-	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
-				      GFP_KERNEL | __GFP_NOWARN);
-	if (gtp->tid_hash == NULL)
-		goto err1;
-
-	gtp->hash_size = hsize;
-
-	for (i = 0; i < hsize; i++) {
-		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
-		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
-	}
-	return 0;
-err1:
-	kfree(gtp->addr_hash);
-	return -ENOMEM;
-}
-
-static struct sock *gtp_encap_enable_socket(int fd, int type,
-					    struct gtp_dev *gtp)
-{
-	struct udp_tunnel_sock_cfg tuncfg = {NULL};
-	struct socket *sock;
-	struct sock *sk;
-	int err;
-
-	pr_debug("enable gtp on %d, %d\n", fd, type);
-
-	sock = sockfd_lookup(fd, &err);
-	if (!sock) {
-		pr_debug("gtp socket fd=%d not found\n", fd);
-		return NULL;
-	}
-
-	sk = sock->sk;
-	if (sk->sk_protocol != IPPROTO_UDP ||
-	    sk->sk_type != SOCK_DGRAM ||
-	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
-		pr_debug("socket fd=%d not UDP\n", fd);
-		sk = ERR_PTR(-EINVAL);
-		goto out_sock;
-	}
-
-	lock_sock(sk);
-	if (sk->sk_user_data) {
-		sk = ERR_PTR(-EBUSY);
-		goto out_rel_sock;
-	}
-
-	sock_hold(sk);
-
-	tuncfg.sk_user_data = gtp;
-	tuncfg.encap_type = type;
-	tuncfg.encap_rcv = gtp_encap_recv;
-	tuncfg.encap_destroy = gtp_encap_destroy;
-
-	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
-
-out_rel_sock:
-	release_sock(sock->sk);
-out_sock:
-	sockfd_put(sock);
-	return sk;
-}
-
-static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
-{
-	struct sock *sk1u = NULL;
-	struct sock *sk0 = NULL;
-	unsigned int role = GTP_ROLE_GGSN;
-
-	if (data[IFLA_GTP_FD0]) {
-		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
-
-		sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
-		if (IS_ERR(sk0))
-			return PTR_ERR(sk0);
-	}
-
-	if (data[IFLA_GTP_FD1]) {
-		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
-
-		sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
-		if (IS_ERR(sk1u)) {
-			gtp_encap_disable_sock(sk0);
-			return PTR_ERR(sk1u);
-		}
-	}
-
-	if (data[IFLA_GTP_ROLE]) {
-		role = nla_get_u32(data[IFLA_GTP_ROLE]);
-		if (role > GTP_ROLE_SGSN) {
-			gtp_encap_disable_sock(sk0);
-			gtp_encap_disable_sock(sk1u);
-			return -EINVAL;
-		}
-	}
-
-	gtp->sk0 = sk0;
-	gtp->sk1u = sk1u;
-	gtp->role = role;
-
-	return 0;
-}
-
 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
 {
 	struct gtp_dev *gtp = NULL;
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 6218f93f5c1a..42f3fb097271 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -822,6 +822,7 @@  enum {
 	IFLA_GTP_FD1,
 	IFLA_GTP_PDP_HASHSIZE,
 	IFLA_GTP_ROLE,
+	IFLA_GTP_CREATE_SOCKETS,
 	__IFLA_GTP_MAX,
 };
 #define IFLA_GTP_MAX (__IFLA_GTP_MAX - 1)