From 1da7910c1d7d29b8bf38ba3870ceb05036e1706f Mon Sep 17 00:00:00 2001
From: Bae Soukjin <soukjin.bae@samsung.com>
Date: Wed, 19 Aug 2020 08:30:51 +0900
Subject: [PATCH] ANDROID: vendor_hooks: Add vendor hook to the net

  android_vh_ptype_head:
    To add a debugging chain to ptype list

  android_vh_kfree_skb
    To sniff the dropped packet at kernel network

Bug: 163716381

Signed-off-by: Bae Soukjin <soukjin.bae@samsung.com>
Change-Id: Ide80bf0a129da31a1824d4a33026ac42be327361
(cherry picked from commit d88b2969cfa78608ad4563e5f4fa84497cc0ffa6)
(cherry picked from commit a8021ba684c584b8a4361d1680f6e466748ab012)
---
 drivers/android/vendor_hooks.c |  3 +++
 include/trace/hooks/net.h      | 25 +++++++++++++++++++++++++
 net/core/dev.c                 |  7 +++++++
 net/core/skbuff.c              |  2 ++
 net/ipv4/tcp_input.c           |  2 ++
 5 files changed, 39 insertions(+)
 create mode 100644 include/trace/hooks/net.h

diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c
index 2cf944fe6c97..05586e74bc43 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -32,6 +32,7 @@
 #include <trace/hooks/cgroup.h>
 #include <trace/hooks/sys.h>
 #include <trace/hooks/iommu.h>
+#include <trace/hooks/net.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -126,3 +127,5 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ufs_send_tm_command);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ufs_check_int_errors);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cgroup_attach);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_iommu_setup_dma_ops);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ptype_head);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_kfree_skb);
diff --git a/include/trace/hooks/net.h b/include/trace/hooks/net.h
new file mode 100644
index 000000000000..31e0f21373e8
--- /dev/null
+++ b/include/trace/hooks/net.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM net
+#define TRACE_INCLUDE_PATH trace/hooks
+
+#if !defined(_TRACE_HOOK_NET_VH_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HOOK_NET_VH_H
+#include <linux/tracepoint.h>
+#include <trace/hooks/vendor_hooks.h>
+
+struct packet_type;
+struct list_head;
+struct sk_buff;
+DECLARE_HOOK(android_vh_ptype_head,
+	TP_PROTO(const struct packet_type *pt, struct list_head *vendor_pt),
+	TP_ARGS(pt, vendor_pt));
+DECLARE_HOOK(android_vh_kfree_skb,
+	TP_PROTO(struct sk_buff *skb), TP_ARGS(skb));
+
+/* macro versions of hooks are no longer required */
+
+#endif /* _TRACE_HOOK_NET_VH_H */
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/net/core/dev.c b/net/core/dev.c
index ef8cf7619baf..db17bc32c674 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -148,6 +148,7 @@
 #include <net/devlink.h>
 #include <linux/pm_runtime.h>
 #include <linux/prandom.h>
+#include <trace/hooks/net.h>
 
 #include "net-sysfs.h"
 
@@ -512,6 +513,12 @@ static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 
 static inline struct list_head *ptype_head(const struct packet_type *pt)
 {
+	struct list_head vendor_pt = { .next  = NULL, };
+
+	trace_android_vh_ptype_head(pt, &vendor_pt);
+	if (vendor_pt.next)
+		return vendor_pt.next;
+
 	if (pt->type == htons(ETH_P_ALL))
 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
 	else
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bbc3b4b62032..06ced658959e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -77,6 +77,7 @@
 #include <linux/capability.h>
 #include <linux/user_namespace.h>
 #include <linux/indirect_call_wrapper.h>
+#include <trace/hooks/net.h>
 
 #include "datagram.h"
 
@@ -754,6 +755,7 @@ void kfree_skb(struct sk_buff *skb)
 	if (!skb_unref(skb))
 		return;
 
+	trace_android_vh_kfree_skb(skb);
 	trace_kfree_skb(skb, __builtin_return_address(0));
 	__kfree_skb(skb);
 }
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 4cf4dd532d1c..f3bbc2d37c8b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -80,6 +80,7 @@
 #include <linux/jump_label_ratelimit.h>
 #include <net/busy_poll.h>
 #include <net/mptcp.h>
+#include <trace/hooks/net.h>
 
 int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
 
@@ -4635,6 +4636,7 @@ static bool tcp_ooo_try_coalesce(struct sock *sk,
 
 static void tcp_drop(struct sock *sk, struct sk_buff *skb)
 {
+	trace_android_vh_kfree_skb(skb);
 	sk_drops_add(sk, skb);
 	__kfree_skb(skb);
 }