diff mbox series

[iproute2-next,v5,1/2] ip: GTP support in ip link

Message ID 20220316110815.46779-2-wojciech.drewek@intel.com (mailing list archive)
State Superseded
Delegated to: David Ahern
Headers show
Series GTP support for ip link and tc flowers | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Wojciech Drewek March 16, 2022, 11:08 a.m. UTC
Support for creating GTP devices through ip link. Two arguments
can be specified by the user when adding device of the GTP type.
 - role (sgsn or ggsn) - indicates whether we are on the GGSN or SGSN
 - hsize - indicates the size of the hash table where PDP sessions
   are stored

IFLA_GTP_FD0 and IFLA_GTP_FD1 arguments would not be provided. Those
are file descriptores to the sockets created in the userspace. Since
we are not going to create sockets in ip link, we don't have to
provide them.

Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Harald Welte <laforge@gnumonks.org>
---
v2: use SPDX tag, use strcmp() instead of matches(), parse
    IFLA_GTP_RESTART_COUNT arg
v3: IFLA_GTP_CREATE_SOCKETS attribute introduced, fix options
    alpha order
v4: resolve merge conflict in ip/Makefile
---
 include/uapi/linux/if_link.h |   2 +
 ip/Makefile                  |   2 +-
 ip/iplink.c                  |   2 +-
 ip/iplink_gtp.c              | 128 +++++++++++++++++++++++++++++++++++
 man/man8/ip-link.8.in        |  29 +++++++-
 5 files changed, 160 insertions(+), 3 deletions(-)
 create mode 100644 ip/iplink_gtp.c

Comments

David Ahern March 17, 2022, 12:56 a.m. UTC | #1
On 3/16/22 5:08 AM, Wojciech Drewek wrote:
> +static void gtp_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
> +{
> +
> +	if (tb[IFLA_GTP_ROLE]) {
> +		__u32 role = rta_getattr_u32(tb[IFLA_GTP_ROLE]);
> +
> +		print_string(PRINT_ANY, "role", "role %s ",
> +			     role == GTP_ROLE_SGSN ? "sgsn" : "ggsn");
> +	}

as a u32 does that mean more roles might get added? Seems like this
should have a attr to string converter that handles future additions.
Wojciech Drewek March 17, 2022, 11:11 a.m. UTC | #2
Hi David,

> -----Original Message-----
> From: David Ahern <dsahern@gmail.com>
> Sent: czwartek, 17 marca 2022 01:57
> To: Drewek, Wojciech <wojciech.drewek@intel.com>; netdev@vger.kernel.org
> Cc: stephen@networkplumber.org
> Subject: Re: [PATCH iproute2-next v5 1/2] ip: GTP support in ip link
> 
> On 3/16/22 5:08 AM, Wojciech Drewek wrote:
> > +static void gtp_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
> > +{
> > +
> > +	if (tb[IFLA_GTP_ROLE]) {
> > +		__u32 role = rta_getattr_u32(tb[IFLA_GTP_ROLE]);
> > +
> > +		print_string(PRINT_ANY, "role", "role %s ",
> > +			     role == GTP_ROLE_SGSN ? "sgsn" : "ggsn");
> > +	}
> 
> as a u32 does that mean more roles might get added? Seems like this
> should have a attr to string converter that handles future additions.

I think no more roles are expected but we can ask Harald.
Of course I can still implement the converter just in case.

Regards,
Wojtek
Harald Welte March 17, 2022, 2:02 p.m. UTC | #3
Hi Wojciech, David,

On Thu, Mar 17, 2022 at 11:11:40AM +0000, Drewek, Wojciech wrote:
> > as a u32 does that mean more roles might get added? Seems like this
> > should have a attr to string converter that handles future additions.
> 
> I think no more roles are expected but we can ask Harald.

I also don't currently know of any situation where we would want to add
more roles.
David Ahern March 17, 2022, 2:47 p.m. UTC | #4
On 3/17/22 8:02 AM, Harald Welte wrote:
> Hi Wojciech, David,
> 
> On Thu, Mar 17, 2022 at 11:11:40AM +0000, Drewek, Wojciech wrote:
>>> as a u32 does that mean more roles might get added? Seems like this
>>> should have a attr to string converter that handles future additions.
>>
>> I think no more roles are expected but we can ask Harald.
> 
> I also don't currently know of any situation where we would want to add
> more roles.
> 

Better safe than giving users wrong information. I would prefer if this
attribute to string conversion handle the 2 known roles and return
"unknown" if a new value pops up.
Wojciech Drewek March 17, 2022, 4:11 p.m. UTC | #5
> -----Original Message-----
> From: David Ahern <dsahern@gmail.com>
> Sent: czwartek, 17 marca 2022 15:48
> To: Harald Welte <laforge@gnumonks.org>; Drewek, Wojciech <wojciech.drewek@intel.com>
> Cc: netdev@vger.kernel.org; stephen@networkplumber.org
> Subject: Re: [PATCH iproute2-next v5 1/2] ip: GTP support in ip link
> 
> On 3/17/22 8:02 AM, Harald Welte wrote:
> > Hi Wojciech, David,
> >
> > On Thu, Mar 17, 2022 at 11:11:40AM +0000, Drewek, Wojciech wrote:
> >>> as a u32 does that mean more roles might get added? Seems like this
> >>> should have a attr to string converter that handles future additions.
> >>
> >> I think no more roles are expected but we can ask Harald.
> >
> > I also don't currently know of any situation where we would want to add
> > more roles.
> >
> 
> Better safe than giving users wrong information. I would prefer if this
> attribute to string conversion handle the 2 known roles and return
> "unknown" if a new value pops up.

Sure, I will include this in the 7th version.
diff mbox series

Patch

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 5f36ff8e8c26..3edc5547f8dd 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -885,6 +885,8 @@  enum {
 	IFLA_GTP_FD1,
 	IFLA_GTP_PDP_HASHSIZE,
 	IFLA_GTP_ROLE,
+	IFLA_GTP_CREATE_SOCKETS,
+	IFLA_GTP_RESTART_COUNT,
 	__IFLA_GTP_MAX,
 };
 #define IFLA_GTP_MAX (__IFLA_GTP_MAX - 1)
diff --git a/ip/Makefile b/ip/Makefile
index 11a361cef5de..0f14c609a4f0 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -12,7 +12,7 @@  IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     iplink_geneve.o iplink_vrf.o iproute_lwtunnel.o ipmacsec.o ipila.o \
     ipvrf.o iplink_xstats.o ipseg6.o iplink_netdevsim.o iplink_rmnet.o \
     ipnexthop.o ipmptcp.o iplink_bareudp.o iplink_wwan.o ipioam6.o \
-    iplink_amt.o iplink_batadv.o
+    iplink_amt.o iplink_batadv.o iplink_gtp.o
 
 RTMONOBJ=rtmon.o
 
diff --git a/ip/iplink.c b/ip/iplink.c
index c0a3a9ad3e62..1fe163794d35 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -51,7 +51,7 @@  void iplink_types_usage(void)
 	/* Remember to add new entry here if new type is added. */
 	fprintf(stderr,
 		"TYPE := { amt | bareudp | bond | bond_slave | bridge | bridge_slave |\n"
-		"          dummy | erspan | geneve | gre | gretap | ifb |\n"
+		"          dummy | erspan | geneve | gre | gretap | gtp | ifb |\n"
 		"          ip6erspan | ip6gre | ip6gretap | ip6tnl |\n"
 		"          ipip | ipoib | ipvlan | ipvtap |\n"
 		"          macsec | macvlan | macvtap |\n"
diff --git a/ip/iplink_gtp.c b/ip/iplink_gtp.c
new file mode 100644
index 000000000000..6ba684876a66
--- /dev/null
+++ b/ip/iplink_gtp.c
@@ -0,0 +1,128 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <stdio.h>
+
+#include "rt_names.h"
+#include "utils.h"
+#include "ip_common.h"
+
+#define GTP_ATTRSET(attrs, type) (((attrs) & (1L << (type))) != 0)
+
+static void print_explain(FILE *f)
+{
+	fprintf(f,
+		"Usage: ... gtp role ROLE\n"
+		"		[ hsize HSIZE ]\n"
+		"		[ restart_count RESTART_COUNT ]\n"
+		"\n"
+		"Where:	ROLE		:= { sgsn | ggsn }\n"
+		"	HSIZE		:= 1-131071\n"
+		"	RESTART_COUNT	:= 0-255\n"
+	);
+}
+
+static void check_duparg(__u32 *attrs, int type, const char *key,
+			 const char *argv)
+{
+	if (!GTP_ATTRSET(*attrs, type)) {
+		*attrs |= (1L << type);
+		return;
+	}
+	duparg2(key, argv);
+}
+
+static int gtp_parse_opt(struct link_util *lu, int argc, char **argv,
+			 struct nlmsghdr *n)
+{
+	__u32 attrs = 0;
+
+	/* When creating GTP device through ip link,
+	 * this flag has to be set.
+	 */
+	addattr8(n, 1024, IFLA_GTP_CREATE_SOCKETS, true);
+
+	while (argc > 0) {
+		if (!strcmp(*argv, "role")) {
+			NEXT_ARG();
+			check_duparg(&attrs, IFLA_GTP_ROLE, "role", *argv);
+			if (!strcmp(*argv, "sgsn"))
+				addattr32(n, 1024, IFLA_GTP_ROLE, GTP_ROLE_SGSN);
+			else if (!strcmp(*argv, "ggsn"))
+				addattr32(n, 1024, IFLA_GTP_ROLE, GTP_ROLE_GGSN);
+			else
+				invarg("invalid role, use sgsn or ggsn", *argv);
+		} else if (!strcmp(*argv, "hsize")) {
+			__u32 hsize;
+
+			NEXT_ARG();
+			check_duparg(&attrs, IFLA_GTP_PDP_HASHSIZE, "hsize", *argv);
+
+			if (get_u32(&hsize, *argv, 0))
+				invarg("invalid PDP hash size", *argv);
+			if (hsize >= 1u << 17)
+				invarg("PDP hash size too big", *argv);
+			addattr32(n, 1024, IFLA_GTP_PDP_HASHSIZE, hsize);
+		} else if (!strcmp(*argv, "restart_count")) {
+			__u8 restart_count;
+
+			NEXT_ARG();
+			check_duparg(&attrs, IFLA_GTP_RESTART_COUNT, "restart_count", *argv);
+
+			if (get_u8(&restart_count, *argv, 10))
+				invarg("invalid restart_count", *argv);
+			addattr8(n, 1024, IFLA_GTP_RESTART_COUNT, restart_count);
+		} else if (!strcmp(*argv, "help")) {
+			print_explain(stderr);
+			return -1;
+		}
+		argc--, argv++;
+	}
+
+	if (!GTP_ATTRSET(attrs, IFLA_GTP_ROLE)) {
+		fprintf(stderr, "gtp: role of the gtp device was not specified\n");
+		return -1;
+	}
+
+	if (!GTP_ATTRSET(attrs, IFLA_GTP_PDP_HASHSIZE))
+		addattr32(n, 1024, IFLA_GTP_PDP_HASHSIZE, 1024);
+
+	return 0;
+}
+
+static void gtp_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+
+	if (tb[IFLA_GTP_ROLE]) {
+		__u32 role = rta_getattr_u32(tb[IFLA_GTP_ROLE]);
+
+		print_string(PRINT_ANY, "role", "role %s ",
+			     role == GTP_ROLE_SGSN ? "sgsn" : "ggsn");
+	}
+
+	if (tb[IFLA_GTP_PDP_HASHSIZE]) {
+		__u32 hsize = rta_getattr_u32(tb[IFLA_GTP_PDP_HASHSIZE]);
+
+		print_uint(PRINT_ANY, "hsize", "hsize %u ", hsize);
+	}
+
+	if (tb[IFLA_GTP_RESTART_COUNT]) {
+		__u8 restart_count = rta_getattr_u8(tb[IFLA_GTP_RESTART_COUNT]);
+
+		print_uint(PRINT_ANY, "restart_count",
+			   "restart_count %u ", restart_count);
+	}
+}
+
+static void gtp_print_help(struct link_util *lu, int argc, char **argv,
+			   FILE *f)
+{
+	print_explain(f);
+}
+
+struct link_util gtp_link_util = {
+	.id		= "gtp",
+	.maxattr	= IFLA_GTP_MAX,
+	.parse_opt	= gtp_parse_opt,
+	.print_opt	= gtp_print_opt,
+	.print_help	= gtp_print_help,
+};
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 93106d7f79ce..7a6753747468 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -243,7 +243,8 @@  ip-link \- network device configuration
 .BR macsec " |"
 .BR netdevsim " |"
 .BR rmnet " |"
-.BR xfrm " ]"
+.BR xfrm " |"
+.BR gtp " ]"
 
 .ti -8
 .IR ETYPE " := [ " TYPE " |"
@@ -392,6 +393,9 @@  Link types:
 .sp
 .BR xfrm
 - Virtual xfrm interface
+.sp
+.BR gtp
+- GPRS Tunneling Protocol
 .in -8
 
 .TP
@@ -1941,6 +1945,29 @@  policies. Policies must be configured with the same key. If not set, the key def
 
 .in -8
 
+.TP
+GTP Type Support
+For a link of type
+.I GTP
+the following additional arguments are supported:
+
+.BI "ip link add " DEVICE " type gtp role " ROLE " hsize " HSIZE
+
+.in +8
+.sp
+.BI role " ROLE "
+- specifies the role of the GTP device, either sgsn or ggsn
+
+.sp
+.BI hsize " HSIZE "
+- specifies size of the hashtable which stores PDP contexts
+
+.sp
+.BI restart_count " RESTART_COUNT "
+- GTP instance restart counter
+
+.in -8
+
 .SS ip link delete - delete virtual link
 
 .TP