[net-next 0/3] tipc: socket diagnostics additions for AF_TIPC

[net-next 0/3] tipc: socket diagnostics additions for AF_TIPC

[GhantaKrishnamurthy MohanKrishna]

The following patchsets add socket diagnostics support for AF_TIPC by
using the sock diag framework. The patchset was created on top of
commit id: fb66cb0.

New iproute2 package is needed to use this functionality which will
be sent for review in a seperate mail.

The commit series improves diagnosis of tipc sockets by exporting the
configuration, states and statistics of sockets.

The series has been co-authored by Parthasarathy Bhuvaragan and
consist of two parts:

1-2:  Adaptations of existing code to support sock_diag framework.
We modify existing functions to support socket diagnostics. Required
information about the sockets are exported.

3:  Step sk_drops during packet drop.
This occurs if the packet cannot be queued due to queue length exceeding
configured thresholds.

The diag module is optional, and if enabled it will be loaded on demand
when needed.

GhantaKrishnamurthy MohanKrishna (3):
  tipc: modify socket iterator for sock_diag
  tipc: implement socket diagnostics for AF_TIPC
  tipc: step sk->sk_drops when rcv buffer is full

 include/uapi/linux/tipc_netlink.h      |  19 +++++
 include/uapi/linux/tipc_sockets_diag.h |  17 +++++
 net/tipc/Kconfig                       |   8 ++
 net/tipc/Makefile                      |   5 ++
 net/tipc/diag.c                        | 114 ++++++++++++++++++++++++++++
 net/tipc/socket.c                      | 134 +++++++++++++++++++++++++++------
 net/tipc/socket.h                      |  10 ++-
 7 files changed, 281 insertions(+), 26 deletions(-)
 create mode 100644 include/uapi/linux/tipc_sockets_diag.h
 create mode 100644 net/tipc/diag.c

-- 
2.1.4

[net-next 1/3] tipc: modify socket iterator for sock_diag

[GhantaKrishnamurthy MohanKrishna]

The current socket iterator function tipc_nl_sk_dump, handles socket
locks and calls __tipc_nl_add_sk for each socket.
To reuse this logic in sock_diag implementation, we do minor
modifications to make these functions generic as described below.

In this commit, we add a two new functions __tipc_nl_sk_walk,
__tipc_nl_add_sk_info and modify tipc_nl_sk_dump, __tipc_nl_add_sk
accordingly.

In __tipc_nl_sk_walk we:
1. acquire and release socket locks
2. for each socket, execute the specified callback function

In __tipc_nl_add_sk we:
- Move the netlink attribute insertion to __tipc_nl_add_sk_info.

tipc_nl_sk_dump calls tipc_nl_sk_walk with __tipc_nl_add_sk as argument.

sock_diag will use these generic functions in a later commit.

There is no functional change in this commit.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
---
 net/tipc/socket.c | 65 +++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 41 insertions(+), 24 deletions(-)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index f93477187a90..8e83b0501d4e 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3154,16 +3154,33 @@ static int __tipc_nl_add_sk_con(struct sk_buff *skb, struct tipc_sock *tsk)
 	return -EMSGSIZE;
 }
 
+static int __tipc_nl_add_sk_info(struct sk_buff *skb, struct tipc_sock
+			  *tsk)
+{
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = tipc_net(net);
+	struct sock *sk = &tsk->sk;
+
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->portid) ||
+	    nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tn->own_addr))
+		return -EMSGSIZE;
+
+	if (tipc_sk_connected(sk)) {
+		if (__tipc_nl_add_sk_con(skb, tsk))
+			return -EMSGSIZE;
+	} else if (!list_empty(&tsk->publications)) {
+		if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
+			return -EMSGSIZE;
+	}
+	return 0;
+}
+
 /* Caller should hold socket lock for the passed tipc socket. */
 static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
 			    struct tipc_sock *tsk)
 {
-	int err;
-	void *hdr;
 	struct nlattr *attrs;
-	struct net *net = sock_net(skb->sk);
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	struct sock *sk = &tsk->sk;
+	void *hdr;
 
 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 			  &tipc_genl_family, NLM_F_MULTI, TIPC_NL_SOCK_GET);
@@ -3173,19 +3190,10 @@ static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
 	attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
 	if (!attrs)
 		goto genlmsg_cancel;
-	if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->portid))
-		goto attr_msg_cancel;
-	if (nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tn->own_addr))
+
+	if (__tipc_nl_add_sk_info(skb, tsk))
 		goto attr_msg_cancel;
 
-	if (tipc_sk_connected(sk)) {
-		err = __tipc_nl_add_sk_con(skb, tsk);
-		if (err)
-			goto attr_msg_cancel;
-	} else if (!list_empty(&tsk->publications)) {
-		if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
-			goto attr_msg_cancel;
-	}
 	nla_nest_end(skb, attrs);
 	genlmsg_end(skb, hdr);
 
@@ -3199,16 +3207,19 @@ static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
 	return -EMSGSIZE;
 }
 
-int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+static int __tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
+			     int (*skb_handler)(struct sk_buff *skb,
+						struct netlink_callback *cb,
+						struct tipc_sock *tsk))
 {
-	int err;
-	struct tipc_sock *tsk;
-	const struct bucket_table *tbl;
-	struct rhash_head *pos;
 	struct net *net = sock_net(skb->sk);
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	u32 tbl_id = cb->args[0];
+	struct tipc_net *tn = tipc_net(net);
+	const struct bucket_table *tbl;
 	u32 prev_portid = cb->args[1];
+	u32 tbl_id = cb->args[0];
+	struct rhash_head *pos;
+	struct tipc_sock *tsk;
+	int err;
 
 	rcu_read_lock();
 	tbl = rht_dereference_rcu((&tn->sk_rht)->tbl, &tn->sk_rht);
@@ -3220,12 +3231,13 @@ int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
 				continue;
 			}
 
-			err = __tipc_nl_add_sk(skb, cb, tsk);
+			err = skb_handler(skb, cb, tsk);
 			if (err) {
 				prev_portid = tsk->portid;
 				spin_unlock_bh(&tsk->sk.sk_lock.slock);
 				goto out;
 			}
+
 			prev_portid = 0;
 			spin_unlock_bh(&tsk->sk.sk_lock.slock);
 		}
@@ -3238,6 +3250,11 @@ int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
+int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	return __tipc_nl_sk_walk(skb, cb, __tipc_nl_add_sk);
+}
+
 /* Caller should hold socket lock for the passed tipc socket. */
 static int __tipc_nl_add_sk_publ(struct sk_buff *skb,
 				 struct netlink_callback *cb,
-- 
2.1.4

[net-next 2/3] tipc: implement socket diagnostics for AF_TIPC

[GhantaKrishnamurthy MohanKrishna]

This commit adds socket diagnostics capability for AF_TIPC in netlink
family NETLINK_SOCK_DIAG in a new kernel module (diag.ko).

The following are key design considerations:
- config TIPC_DIAG has default y, like INET_DIAG.
- only requests with flag NLM_F_DUMP is supported (dump all).
- tipc_sock_diag_req message is introduced to send filter parameters.
- the response attributes are of TLV, some nested.

To avoid exposing data structures between diag and tipc modules and
avoid code duplication, the following additions are required:
- export tipc_nl_sk_walk function to reuse socket iterator.
- export tipc_sk_fill_sock_diag to fill the tipc diag attributes.
- create a sock_diag response message in __tipc_add_sock_diag defined
  in diag.c and use the above exported tipc_sk_fill_sock_diag
  to fill response.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
---
 include/uapi/linux/tipc_netlink.h      |  18 ++++++
 include/uapi/linux/tipc_sockets_diag.h |  17 +++++
 net/tipc/Kconfig                       |   8 +++
 net/tipc/Makefile                      |   5 ++
 net/tipc/diag.c                        | 114 +++++++++++++++++++++++++++++++++
 net/tipc/socket.c                      |  72 +++++++++++++++++++--
 net/tipc/socket.h                      |  10 ++-
 7 files changed, 238 insertions(+), 6 deletions(-)
 create mode 100644 include/uapi/linux/tipc_sockets_diag.h
 create mode 100644 net/tipc/diag.c

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
index 469aa67a5ecb..d7cec0480d70 100644
--- a/include/uapi/linux/tipc_netlink.h
+++ b/include/uapi/linux/tipc_netlink.h
@@ -114,6 +114,13 @@ enum {
 	TIPC_NLA_SOCK_REF,		/* u32 */
 	TIPC_NLA_SOCK_CON,		/* nest */
 	TIPC_NLA_SOCK_HAS_PUBL,		/* flag */
+	TIPC_NLA_SOCK_STAT,		/* nest */
+	TIPC_NLA_SOCK_TYPE,		/* u32 */
+	TIPC_NLA_SOCK_INO,		/* u32 */
+	TIPC_NLA_SOCK_UID,		/* u32 */
+	TIPC_NLA_SOCK_TIPC_STATE,	/* u32 */
+	TIPC_NLA_SOCK_COOKIE,		/* u64 */
+	TIPC_NLA_SOCK_PAD,		/* flag */
 
 	__TIPC_NLA_SOCK_MAX,
 	TIPC_NLA_SOCK_MAX = __TIPC_NLA_SOCK_MAX - 1
@@ -238,6 +245,17 @@ enum {
 	TIPC_NLA_CON_MAX = __TIPC_NLA_CON_MAX - 1
 };
 
+/* Nest, socket statistics info */
+enum {
+	TIPC_NLA_SOCK_STAT_RCVQ,	/* u32 */
+	TIPC_NLA_SOCK_STAT_SENDQ,	/* u32 */
+	TIPC_NLA_SOCK_STAT_LINK_CONG,	/* flag */
+	TIPC_NLA_SOCK_STAT_CONN_CONG,	/* flag */
+
+	__TIPC_NLA_SOCK_STAT_MAX,
+	TIPC_NLA_SOCK_STAT_MAX = __TIPC_NLA_SOCK_STAT_MAX - 1
+};
+
 /* Nest, link propreties. Valid for link, media and bearer */
 enum {
 	TIPC_NLA_PROP_UNSPEC,
diff --git a/include/uapi/linux/tipc_sockets_diag.h b/include/uapi/linux/tipc_sockets_diag.h
new file mode 100644
index 000000000000..7678cf2f0dcc
--- /dev/null
+++ b/include/uapi/linux/tipc_sockets_diag.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* AF_TIPC sock_diag interface for querying open sockets */
+
+#ifndef _UAPI__TIPC_SOCKETS_DIAG_H__
+#define _UAPI__TIPC_SOCKETS_DIAG_H__
+
+#include <linux/types.h>
+#include <linux/sock_diag.h>
+
+/* Request */
+struct tipc_sock_diag_req {
+	__u8	sdiag_family;	/* must be AF_TIPC */
+	__u8	sdiag_protocol;	/* must be 0 */
+	__u16	pad;		/* must be 0 */
+	__u32	tidiag_states;	/* query*/
+};
+#endif /* _UAPI__TIPC_SOCKETS_DIAG_H__ */
diff --git a/net/tipc/Kconfig b/net/tipc/Kconfig
index c25a3a149dc4..e450212121d2 100644
--- a/net/tipc/Kconfig
+++ b/net/tipc/Kconfig
@@ -34,3 +34,11 @@ config TIPC_MEDIA_UDP
 	  Saying Y here will enable support for running TIPC over IP/UDP
 	bool
 	default y
+
+config TIPC_DIAG
+	tristate "TIPC: socket monitoring interface"
+	depends on TIPC
+	default y
+	---help---
+	Support for TIPC socket monitoring interface used by ss tool.
+	If unsure, say Y.
diff --git a/net/tipc/Makefile b/net/tipc/Makefile
index 1edb7192aa2f..aca168f2abb1 100644
--- a/net/tipc/Makefile
+++ b/net/tipc/Makefile
@@ -14,3 +14,8 @@ tipc-y	+= addr.o bcast.o bearer.o \
 tipc-$(CONFIG_TIPC_MEDIA_UDP)	+= udp_media.o
 tipc-$(CONFIG_TIPC_MEDIA_IB)	+= ib_media.o
 tipc-$(CONFIG_SYSCTL)		+= sysctl.o
+
+
+obj-$(CONFIG_TIPC_DIAG)	+= diag.o
+
+tipc_diag-y	:= diag.o
diff --git a/net/tipc/diag.c b/net/tipc/diag.c
new file mode 100644
index 000000000000..46d9cd62f781
--- /dev/null
+++ b/net/tipc/diag.c
@@ -0,0 +1,114 @@
+/*
+ * net/tipc/diag.c: TIPC socket diag
+ *
+ * Copyright (c) 2018, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "ASIS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "core.h"
+#include "socket.h"
+#include <linux/sock_diag.h>
+#include <linux/tipc_sockets_diag.h>
+
+static u64 __tipc_diag_gen_cookie(struct sock *sk)
+{
+	u32 res[2];
+
+	sock_diag_save_cookie(sk, res);
+	return *((u64 *)res);
+}
+
+static int __tipc_add_sock_diag(struct sk_buff *skb,
+				struct netlink_callback *cb,
+				struct tipc_sock *tsk)
+{
+	struct tipc_sock_diag_req *req = nlmsg_data(cb->nlh);
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = nlmsg_put_answer(skb, cb, SOCK_DIAG_BY_FAMILY, 0,
+			       NLM_F_MULTI);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	err = tipc_sk_fill_sock_diag(skb, tsk, req->tidiag_states,
+				     __tipc_diag_gen_cookie);
+	if (err)
+		return err;
+
+	nlmsg_end(skb, nlh);
+	return 0;
+}
+
+static int tipc_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	return tipc_nl_sk_walk(skb, cb, __tipc_add_sock_diag);
+}
+
+static int tipc_sock_diag_handler_dump(struct sk_buff *skb,
+				       struct nlmsghdr *h)
+{
+	int hdrlen = sizeof(struct tipc_sock_diag_req);
+	struct net *net = sock_net(skb->sk);
+
+	if (nlmsg_len(h) < hdrlen)
+		return -EINVAL;
+
+	if (h->nlmsg_flags & NLM_F_DUMP) {
+		struct netlink_dump_control c = {
+			.dump = tipc_diag_dump,
+		};
+		netlink_dump_start(net->diag_nlsk, skb, h, &c);
+		return 0;
+	}
+	return -EOPNOTSUPP;
+}
+
+static const struct sock_diag_handler tipc_sock_diag_handler = {
+	.family = AF_TIPC,
+	.dump = tipc_sock_diag_handler_dump,
+};
+
+static int __init tipc_diag_init(void)
+{
+	return sock_diag_register(&tipc_sock_diag_handler);
+}
+
+static void __exit tipc_diag_exit(void)
+{
+	sock_diag_unregister(&tipc_sock_diag_handler);
+}
+
+module_init(tipc_diag_init);
+module_exit(tipc_diag_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, AF_TIPC);
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 8e83b0501d4e..31fdd13d444e 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3207,10 +3207,10 @@ static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
 	return -EMSGSIZE;
 }
 
-static int __tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
-			     int (*skb_handler)(struct sk_buff *skb,
-						struct netlink_callback *cb,
-						struct tipc_sock *tsk))
+int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
+		    int (*skb_handler)(struct sk_buff *skb,
+				       struct netlink_callback *cb,
+				       struct tipc_sock *tsk))
 {
 	struct net *net = sock_net(skb->sk);
 	struct tipc_net *tn = tipc_net(net);
@@ -3249,10 +3249,72 @@ static int __tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
 
 	return skb->len;
 }
+EXPORT_SYMBOL(tipc_nl_sk_walk);
+
+int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct tipc_sock *tsk,
+			   u32 sk_filter_state,
+			   u64 (*tipc_diag_gen_cookie)(struct sock *sk))
+{
+	struct sock *sk = &tsk->sk;
+	struct nlattr *attrs;
+	struct nlattr *stat;
+
+	/*filter response w.r.t sk_state*/
+	if (!(sk_filter_state & (1 << sk->sk_state)))
+		return 0;
+
+	attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
+	if (!attrs)
+		goto msg_cancel;
+
+	if (__tipc_nl_add_sk_info(skb, tsk))
+		goto attr_msg_cancel;
+
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_TYPE, (u32)sk->sk_type) ||
+	    nla_put_u32(skb, TIPC_NLA_SOCK_TIPC_STATE, (u32)sk->sk_state) ||
+	    nla_put_u32(skb, TIPC_NLA_SOCK_INO, sock_i_ino(sk)) ||
+	    nla_put_u32(skb, TIPC_NLA_SOCK_UID,
+			from_kuid_munged(sk_user_ns(sk), sock_i_uid(sk))) ||
+	    nla_put_u64_64bit(skb, TIPC_NLA_SOCK_COOKIE,
+			      tipc_diag_gen_cookie(sk),
+			      TIPC_NLA_SOCK_PAD))
+		goto attr_msg_cancel;
+
+	stat = nla_nest_start(skb, TIPC_NLA_SOCK_STAT);
+	if (!stat)
+		goto attr_msg_cancel;
+
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_STAT_RCVQ,
+			skb_queue_len(&sk->sk_receive_queue)) ||
+	    nla_put_u32(skb, TIPC_NLA_SOCK_STAT_SENDQ,
+			skb_queue_len(&sk->sk_write_queue)))
+		goto stat_msg_cancel;
+
+	if (tsk->cong_link_cnt &&
+	    nla_put_flag(skb, TIPC_NLA_SOCK_STAT_LINK_CONG))
+		goto stat_msg_cancel;
+
+	if (tsk_conn_cong(tsk) &&
+	    nla_put_flag(skb, TIPC_NLA_SOCK_STAT_CONN_CONG))
+		goto stat_msg_cancel;
+
+	nla_nest_end(skb, stat);
+	nla_nest_end(skb, attrs);
+
+	return 0;
+
+stat_msg_cancel:
+	nla_nest_cancel(skb, stat);
+attr_msg_cancel:
+	nla_nest_cancel(skb, attrs);
+msg_cancel:
+	return -EMSGSIZE;
+}
+EXPORT_SYMBOL(tipc_sk_fill_sock_diag);
 
 int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
-	return __tipc_nl_sk_walk(skb, cb, __tipc_nl_add_sk);
+	return tipc_nl_sk_walk(skb, cb, __tipc_nl_add_sk);
 }
 
 /* Caller should hold socket lock for the passed tipc socket. */
diff --git a/net/tipc/socket.h b/net/tipc/socket.h
index 06fb5944cf76..aae3fd4cd06c 100644
--- a/net/tipc/socket.h
+++ b/net/tipc/socket.h
@@ -49,6 +49,8 @@
 #define RCVBUF_DEF  (FLOWCTL_BLK_SZ * 1024 * 2)
 #define RCVBUF_MAX  (FLOWCTL_BLK_SZ * 1024 * 16)
 
+struct tipc_sock;
+
 int tipc_socket_init(void);
 void tipc_socket_stop(void);
 void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq);
@@ -59,5 +61,11 @@ int tipc_sk_rht_init(struct net *net);
 void tipc_sk_rht_destroy(struct net *net);
 int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_publ_dump(struct sk_buff *skb, struct netlink_callback *cb);
-
+int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct tipc_sock *tsk,
+			   u32 sk_filter_state,
+			   u64 (*tipc_diag_gen_cookie)(struct sock *sk));
+int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
+		    int (*skb_handler)(struct sk_buff *skb,
+				       struct netlink_callback *cb,
+				       struct tipc_sock *tsk));
 #endif
-- 
2.1.4

[net-next 3/3] tipc: step sk->sk_drops when rcv buffer is full

[GhantaKrishnamurthy MohanKrishna]

Currently when tipc is unable to queue a received message on a
socket, the message is rejected back to the sender with error
TIPC_ERR_OVERLOAD. However, the application on this socket
has no knowledge about these discards.

In this commit, we try to step the sk_drops counter when tipc
is unable to queue a received message. Export sk_drops
using tipc socket diagnostics.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
---
 include/uapi/linux/tipc_netlink.h | 1 +
 net/tipc/socket.c                 | 9 +++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
index d7cec0480d70..d896ded51bcb 100644
--- a/include/uapi/linux/tipc_netlink.h
+++ b/include/uapi/linux/tipc_netlink.h
@@ -251,6 +251,7 @@ enum {
 	TIPC_NLA_SOCK_STAT_SENDQ,	/* u32 */
 	TIPC_NLA_SOCK_STAT_LINK_CONG,	/* flag */
 	TIPC_NLA_SOCK_STAT_CONN_CONG,	/* flag */
+	TIPC_NLA_SOCK_STAT_DROP,	/* u32 */
 
 	__TIPC_NLA_SOCK_STAT_MAX,
 	TIPC_NLA_SOCK_STAT_MAX = __TIPC_NLA_SOCK_STAT_MAX - 1
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 31fdd13d444e..a084c78408fb 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2122,8 +2122,10 @@ static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,
 		    (!sk_conn && msg_connected(hdr)) ||
 		    (!grp && msg_in_group(hdr)))
 			err = TIPC_ERR_NO_PORT;
-		else if (sk_rmem_alloc_get(sk) + skb->truesize >= limit)
+		else if (sk_rmem_alloc_get(sk) + skb->truesize >= limit) {
+			atomic_inc(&sk->sk_drops);
 			err = TIPC_ERR_OVERLOAD;
+		}
 
 		if (unlikely(err)) {
 			tipc_skb_reject(net, err, skb, xmitq);
@@ -2202,6 +2204,7 @@ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk,
 
 		/* Overload => reject message back to sender */
 		onode = tipc_own_addr(sock_net(sk));
+		atomic_inc(&sk->sk_drops);
 		if (tipc_msg_reverse(onode, &skb, TIPC_ERR_OVERLOAD))
 			__skb_queue_tail(xmitq, skb);
 		break;
@@ -3287,7 +3290,9 @@ int tipc_sk_fill_sock_diag(struct sk_buff *skb, struct tipc_sock *tsk,
 	if (nla_put_u32(skb, TIPC_NLA_SOCK_STAT_RCVQ,
 			skb_queue_len(&sk->sk_receive_queue)) ||
 	    nla_put_u32(skb, TIPC_NLA_SOCK_STAT_SENDQ,
-			skb_queue_len(&sk->sk_write_queue)))
+			skb_queue_len(&sk->sk_write_queue)) ||
+	    nla_put_u32(skb, TIPC_NLA_SOCK_STAT_DROP,
+			atomic_read(&sk->sk_drops)))
 		goto stat_msg_cancel;
 
 	if (tsk->cong_link_cnt &&
-- 
2.1.4

Re: [net-next 0/3] tipc: socket diagnostics additions for AF_TIPC

[David Miller]

From: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Date: Wed, 21 Mar 2018 14:37:42 +0100

> The following patchsets add socket diagnostics support for AF_TIPC by
> using the sock diag framework. The patchset was created on top of
> commit id: fb66cb0.

Series applied, thank you.

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Re: [net-next 2/3] tipc: implement socket diagnostics for AF_TIPC

[Eric Dumazet]

On 03/21/2018 06:37 AM, GhantaKrishnamurthy MohanKrishna wrote:
> This commit adds socket diagnostics capability for AF_TIPC in netlink
> family NETLINK_SOCK_DIAG in a new kernel module (diag.ko).

...
> +static u64 __tipc_diag_gen_cookie(struct sock *sk)
> +{
> +	u32 res[2];
> +
> +	sock_diag_save_cookie(sk, res);
> +	return *((u64 *)res);
> +}

I am pretty sure some combination of compiler / arch could be not happy 
with this assumption that res[] is aligned to allow an u64 to be read like that.

RE: [net-next 2/3] tipc: implement socket diagnostics for AF_TIPC

[Jon Maloy]

What about a union?
///jon

> -----Original Message-----
> From: Eric Dumazet <eric.dumazet@gmail.com>
> Sent: Friday, 29 June, 2018 09:58
> To: Mohan Krishna Ghanta Krishnamurthy <mohan.krishna.ghanta.krishnamurthy@ericsson.com>; tipc-
> discussion@lists.sourceforge.net; Jon Maloy <jon.maloy@ericsson.com>; maloy@donjonn.com; ying.xue@windriver.com;
> netdev@vger.kernel.org; davem@davemloft.net
> Cc: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
> Subject: Re: [net-next 2/3] tipc: implement socket diagnostics for AF_TIPC
> 
> 
> 
> On 03/21/2018 06:37 AM, GhantaKrishnamurthy MohanKrishna wrote:
> > This commit adds socket diagnostics capability for AF_TIPC in netlink
> > family NETLINK_SOCK_DIAG in a new kernel module (diag.ko).
> 
> ...
> > +static u64 __tipc_diag_gen_cookie(struct sock *sk)
> > +{
> > +	u32 res[2];
> > +
> > +	sock_diag_save_cookie(sk, res);
> > +	return *((u64 *)res);
> > +}
> 
> I am pretty sure some combination of compiler / arch could be not happy
> with this assumption that res[] is aligned to allow an u64 to be read like that.
>