ANDROID: GKI: Add hooks for TCP parameter management.

These hooks allow vendor modules to perform more operations
on tcp sockets, thereby ensure efficient transmission of application
data.

'trace_android_vh_tcp_fastsyn', 'trace_android_vh_tcp_state_change',
'trace_android_vh_tcp_select_window', 'trace_android_vh_tcp_update_rtt'
and 'trace_android_vh_tcp_sock_error' are invoked during different
state transitions of a TCP connection. The vendor module will record
certain parameter information and adopt different strategies based
on the TCP state to ensure the smooth transmission of
application data packets.

Bug: 354619847
Change-Id: Ia900227adb89592eb81b575f8fcd8f356cd00f7b
Signed-off-by: jiangxinpei <huangdezhi@hihonor.com>
(cherry picked from commit e8020c62826dea209e70c5b47326592d56dcc254)

drivers/android/vendor_hooks.c

@@ -243,6 +243,11 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_flush_wq_wait_start);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_flush_wq_wait_finish);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_flush_work_wait_start);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_flush_work_wait_finish);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tcp_sock_error);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tcp_fastsyn);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tcp_state_change);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tcp_select_window);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tcp_update_rtt);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sk_alloc);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sk_free);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_enable_thermal_genl_check);

include/trace/hooks/net.h

@@ -8,6 +8,16 @@
 #define _TRACE_HOOK_NET_VH_H
 #include <trace/hooks/vendor_hooks.h>
 
+#ifndef TCP_STATE_CHANGE_REASON_H
+#define TCP_STATE_CHANGE_REASON_H
+enum tcp_state_change_reason {
+	TCP_STATE_CHANGE_REASON_NORMAL,
+	TCP_STATE_CHANGE_REASON_SYN_RST,
+	TCP_STATE_CHANGE_REASON_SYN_TIMEOUT,
+	TCP_STATE_CHANGE_REASON_RETRANSMIT
+};
+#endif
+
 struct packet_type;
 struct list_head;
 DECLARE_HOOK(android_vh_ptype_head,
@@ -46,6 +56,17 @@ DECLARE_HOOK(android_vh_udp_unicast_rcv_skb,
 DECLARE_HOOK(android_vh_udp6_unicast_rcv_skb,
 	TP_PROTO(struct sk_buff *skb, struct sock *sk),
 	TP_ARGS(skb, sk));
+DECLARE_HOOK(android_vh_tcp_sock_error,
+	TP_PROTO(struct sock *sk), TP_ARGS(sk));
+DECLARE_HOOK(android_vh_tcp_fastsyn,
+	TP_PROTO(struct sock *sk), TP_ARGS(sk));
+DECLARE_HOOK(android_vh_tcp_select_window,
+	TP_PROTO(struct sock *sk, uint32_t *win), TP_ARGS(sk, win));
+DECLARE_HOOK(android_vh_tcp_state_change,
+	TP_PROTO(struct sock *sk, enum tcp_state_change_reason reason, int state),
+	TP_ARGS(sk, reason, state));
+DECLARE_HOOK(android_vh_tcp_update_rtt,
+	TP_PROTO(struct sock *sk, long rtt), TP_ARGS(sk, rtt));
 DECLARE_HOOK(android_vh_sk_alloc,
 	TP_PROTO(struct sock *sk), TP_ARGS(sk));
 DECLARE_HOOK(android_vh_sk_free,

net/ipv4/tcp.c

@@ -284,6 +284,7 @@
 #include <net/hotdata.h>
 #include <trace/events/tcp.h>
 #include <net/rps.h>
+#include <trace/hooks/net.h>
 
 #include "../core/devmem.h"
 
@@ -2869,6 +2870,8 @@ void tcp_set_state(struct sock *sk, int state)
 {
 	int oldstate = sk->sk_state;
 
+	trace_android_vh_tcp_state_change(sk, TCP_STATE_CHANGE_REASON_NORMAL, state);
+
 	/* We defined a new enum for TCP states that are exported in BPF
 	 * so as not force the internal TCP states to be frozen. The
 	 * following checks will detect if an internal state value ever

net/ipv4/tcp_input.c

@@ -3222,6 +3222,8 @@ static bool tcp_ack_update_rtt(struct sock *sk, const int flag,
 	if (seq_rtt_us < 0)
 		return false;
 
+	trace_android_vh_tcp_update_rtt(sk, seq_rtt_us);
+
 	/* ca_rtt_us >= 0 is counting on the invariant that ca_rtt_us is
 	 * always taken together with ACK, SACK, or TS-opts. Any negative
 	 * values will be skipped with the seq_rtt_us < 0 check above.
@@ -4622,6 +4624,8 @@ void tcp_fin(struct sock *sk)
 		tcp_sack_reset(&tp->rx_opt);
 
 	if (!sock_flag(sk, SOCK_DEAD)) {
+		trace_android_vh_tcp_sock_error(sk);
+
 		sk->sk_state_change(sk);
 
 		/* Do not send POLL_HUP for half duplex close. */
@@ -6483,6 +6487,8 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 
 		if (th->rst) {
 			tcp_reset(sk, skb);
+
+			trace_android_vh_tcp_state_change(sk, TCP_STATE_CHANGE_REASON_SYN_RST, 0);
 consume:
 			__kfree_skb(skb);
 			return 0;

net/ipv4/tcp_output.c

@@ -274,6 +274,9 @@ static u16 tcp_select_window(struct sock *sk)
 
 	cur_win = tcp_receive_window(tp);
 	new_win = __tcp_select_window(sk);
+
+	trace_android_vh_tcp_select_window(sk, &new_win);
+
 	if (new_win < cur_win) {
 		/* Danger Will Robinson!
 		 * Don't update rcv_wup/rcv_wnd here or else

net/ipv4/tcp_timer.c

@@ -293,10 +293,15 @@ static int tcp_write_timeout(struct sock *sk)
 
 	if (expired) {
 		/* Has it gone just too far? */
+
+		trace_android_vh_tcp_state_change(sk, TCP_STATE_CHANGE_REASON_SYN_TIMEOUT, 0);
+
 		tcp_write_err(sk);
 		return 1;
 	}
 
+	trace_android_vh_tcp_state_change(sk, TCP_STATE_CHANGE_REASON_RETRANSMIT, 0);
+
 	if (sk_rethink_txhash(sk)) {
 		tp->timeout_rehash++;
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEOUTREHASH);
@@ -667,6 +672,8 @@ out_reset_timer:
 		 */
 		icsk->icsk_backoff++;
 		icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);
+
+		trace_android_vh_tcp_fastsyn(sk);
 	}
 	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 				  tcp_clamp_rto_to_user_timeout(sk), TCP_RTO_MAX);