diff mbox series

[net-next,v3,8/9] net: tcp: add skb drop reasons to route_req()

Message ID 20220610034204.67901-9-imagedong@tencent.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net: tcp: add skb drop reasons to tcp state change | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
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: 5651 this patch: 5651
netdev/cc_maintainers warning 3 maintainers not CCed: mptcp@lists.linux.dev matthieu.baerts@tessares.net mathew.j.martineau@linux.intel.com
netdev/build_clang success Errors and warnings before: 1213 this patch: 1213
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5800 this patch: 5800
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 109 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Menglong Dong June 10, 2022, 3:42 a.m. UTC 
From: Menglong Dong <imagedong@tencent.com>

Add skb drop reasons to the route_req() in struct tcp_request_sock_ops.
Following functions are involved:

  tcp_v4_route_req()
  tcp_v6_route_req()
  subflow_v4_route_req()
  subflow_v6_route_req()

And the new reason SKB_DROP_REASON_LSM is added, which is used when
skb is dropped by LSM.

Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
---
 include/net/dropreason.h |  2 ++
 include/net/tcp.h        |  3 ++-
 net/ipv4/tcp_input.c     |  2 +-
 net/ipv4/tcp_ipv4.c      | 14 +++++++++++---
 net/ipv6/tcp_ipv6.c      | 14 +++++++++++---
 net/mptcp/subflow.c      | 10 ++++++----
 6 files changed, 33 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/include/net/dropreason.h b/include/net/dropreason.h
index 3c6f8e0f7f16..22e9299e4bfe 100644
--- a/include/net/dropreason.h
+++ b/include/net/dropreason.h
@@ -264,6 +264,8 @@  enum skb_drop_reason {
 	 * 'SYN' packet
 	 */
 	SKB_DROP_REASON_TIMEWAIT,
+	/** @SKB_DROP_REASON_LSM: dropped by LSM */
+	SKB_DROP_REASON_LSM,
 	/**
 	 * @SKB_DROP_REASON_MAX: the maximum of drop reason, which shouldn't be
 	 * used as a real 'reason'
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 88217b8d95ac..ed57c331fdeb 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2075,7 +2075,8 @@  struct tcp_request_sock_ops {
 	struct dst_entry *(*route_req)(const struct sock *sk,
 				       struct sk_buff *skb,
 				       struct flowi *fl,
-				       struct request_sock *req);
+				       struct request_sock *req,
+				       enum skb_drop_reason *reason);
 	u32 (*init_seq)(const struct sk_buff *skb);
 	u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb);
 	int (*send_synack)(const struct sock *sk, struct dst_entry *dst,
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6f7dd2564b9b..9b9247b34a6c 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6957,7 +6957,7 @@  enum skb_drop_reason tcp_conn_request(struct request_sock_ops *rsk_ops,
 	/* Note: tcp_v6_init_req() might override ir_iif for link locals */
 	inet_rsk(req)->ir_iif = inet_request_bound_dev_if(sk, skb);
 
-	dst = af_ops->route_req(sk, skb, &fl, req);
+	dst = af_ops->route_req(sk, skb, &fl, req, &reason);
 	if (!dst)
 		goto drop_and_free;
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e7bd2f410a4a..dcaf2bac4f55 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1423,14 +1423,22 @@  static void tcp_v4_init_req(struct request_sock *req,
 static struct dst_entry *tcp_v4_route_req(const struct sock *sk,
 					  struct sk_buff *skb,
 					  struct flowi *fl,
-					  struct request_sock *req)
+					  struct request_sock *req,
+					  enum skb_drop_reason *reason)
 {
+	struct dst_entry *dst;
+
 	tcp_v4_init_req(req, sk, skb);
 
-	if (security_inet_conn_request(sk, skb, req))
+	if (security_inet_conn_request(sk, skb, req)) {
+		SKB_DR_SET(*reason, LSM);
 		return NULL;
+	}
 
-	return inet_csk_route_req(sk, &fl->u.ip4, req);
+	dst = inet_csk_route_req(sk, &fl->u.ip4, req);
+	if (!dst)
+		SKB_DR_SET(*reason, IP_OUTNOROUTES);
+	return dst;
 }
 
 struct request_sock_ops tcp_request_sock_ops __read_mostly = {
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 41551a3b679b..6e2d67238e11 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -802,14 +802,22 @@  static void tcp_v6_init_req(struct request_sock *req,
 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 					  struct sk_buff *skb,
 					  struct flowi *fl,
-					  struct request_sock *req)
+					  struct request_sock *req,
+					  enum skb_drop_reason *reason)
 {
+	struct dst_entry *dst;
+
 	tcp_v6_init_req(req, sk, skb);
 
-	if (security_inet_conn_request(sk, skb, req))
+	if (security_inet_conn_request(sk, skb, req)) {
+		SKB_DR_SET(*reason, LSM);
 		return NULL;
+	}
 
-	return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
+	dst = inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
+	if (!dst)
+		SKB_DR_SET(*reason, IP_OUTNOROUTES);
+	return dst;
 }
 
 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 5a1d05c3a1ef..654cc602ff2c 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -285,7 +285,8 @@  EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req);
 static struct dst_entry *subflow_v4_route_req(const struct sock *sk,
 					      struct sk_buff *skb,
 					      struct flowi *fl,
-					      struct request_sock *req)
+					      struct request_sock *req,
+					      enum skb_drop_reason *reason)
 {
 	struct dst_entry *dst;
 	int err;
@@ -293,7 +294,7 @@  static struct dst_entry *subflow_v4_route_req(const struct sock *sk,
 	tcp_rsk(req)->is_mptcp = 1;
 	subflow_init_req(req, sk);
 
-	dst = tcp_request_sock_ipv4_ops.route_req(sk, skb, fl, req);
+	dst = tcp_request_sock_ipv4_ops.route_req(sk, skb, fl, req, reason);
 	if (!dst)
 		return NULL;
 
@@ -311,7 +312,8 @@  static struct dst_entry *subflow_v4_route_req(const struct sock *sk,
 static struct dst_entry *subflow_v6_route_req(const struct sock *sk,
 					      struct sk_buff *skb,
 					      struct flowi *fl,
-					      struct request_sock *req)
+					      struct request_sock *req,
+					      enum skb_drop_reason *reason)
 {
 	struct dst_entry *dst;
 	int err;
@@ -319,7 +321,7 @@  static struct dst_entry *subflow_v6_route_req(const struct sock *sk,
 	tcp_rsk(req)->is_mptcp = 1;
 	subflow_init_req(req, sk);
 
-	dst = tcp_request_sock_ipv6_ops.route_req(sk, skb, fl, req);
+	dst = tcp_request_sock_ipv6_ops.route_req(sk, skb, fl, req, reason);
 	if (!dst)
 		return NULL;