tcp_timer.c: Add kernel-doc function descriptions (c380d37e) · Commits · 方亚芬 / raspberrypi_linux

net/ipv4/tcp_timer.c

+64 −17

Original line number	Diff line number	Diff line
		@@ -24,6 +24,13 @@

		int sysctl_tcp_thin_linear_timeouts __read_mostly;

		/**
		* tcp_write_err() - close socket and save error info
		* @sk: The socket the error has appeared on.
		*
		* Returns: Nothing (void)
		*/

		static void tcp_write_err(struct sock *sk)
		{
		sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
		@@ -33,7 +40,12 @@ static void tcp_write_err(struct sock *sk)
		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONTIMEOUT);
		}

		/* Do not allow orphaned sockets to eat all our resources.
		/**
		* tcp_out_of_resources() - Close socket if out of resources
		* @sk: pointer to current socket
		* @do_reset: send a last packet with reset flag
		*
		* Do not allow orphaned sockets to eat all our resources.
		* This is direct violation of TCP specs, but it is required
		* to prevent DoS attacks. It is called when a retransmission timeout
		* or zero probe timeout occurs on orphaned socket.
		@@ -74,7 +86,11 @@ static int tcp_out_of_resources(struct sock *sk, bool do_reset)
		return 0;
		}

		/* Calculate maximal number or retries on an orphaned socket. */
		/**
		* tcp_orphan_retries() - Returns maximal number of retries on an orphaned socket
		* @sk: Pointer to the current socket.
		* @alive: bool, socket alive state
		*/
		static int tcp_orphan_retries(struct sock *sk, bool alive)
		{
		int retries = sock_net(sk)->ipv4.sysctl_tcp_orphan_retries; /* May be zero. */
		@@ -115,10 +131,22 @@ static void tcp_mtu_probing(struct inet_connection_sock icsk, struct sock sk)
		}
		}

		/* This function calculates a "timeout" which is equivalent to the timeout of a
		* TCP connection after "boundary" unsuccessful, exponentially backed-off

		/**
		* retransmits_timed_out() - returns true if this connection has timed out
		* @sk: The current socket
		* @boundary: max number of retransmissions
		* @timeout: A custom timeout value.
		* If set to 0 the default timeout is calculated and used.
		* Using TCP_RTO_MIN and the number of unsuccessful retransmits.
		* @syn_set: true if the SYN Bit was set.
		*
		* The default "timeout" value this function can calculate and use
		* is equivalent to the timeout of a TCP Connection
		* after "boundary" unsuccessful, exponentially backed-off
		* retransmissions with an initial RTO of TCP_RTO_MIN or TCP_TIMEOUT_INIT if
		* syn_set flag is set.
		*
		*/
		static bool retransmits_timed_out(struct sock *sk,
		unsigned int boundary,
		@@ -257,6 +285,16 @@ out:
		sk_mem_reclaim(sk);
		}


		/**
		* tcp_delack_timer() - The TCP delayed ACK timeout handler
		* @data: Pointer to the current socket. (gets casted to struct sock *)
		*
		* This function gets (indirectly) called when the kernel timer for a TCP packet
		* of this socket expires. Calls tcp_delack_timer_handler() to do the actual work.
		*
		* Returns: Nothing (void)
		*/
		static void tcp_delack_timer(unsigned long data)
		{
		struct sock sk = (struct sock )data;
		@@ -350,10 +388,18 @@ static void tcp_fastopen_synack_timer(struct sock *sk)
		TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
		}

		/*
		* The TCP retransmit timer.
		*/

		/**
		* tcp_retransmit_timer() - The TCP retransmit timeout handler
		* @sk: Pointer to the current socket.
		*
		* This function gets called when the kernel timer for a TCP packet
		* of this socket expires.
		*
		* It handles retransmission, timer adjustment and other necesarry measures.
		*
		* Returns: Nothing (void)
		*/
		void tcp_retransmit_timer(struct sock *sk)
		{
		struct tcp_sock *tp = tcp_sk(sk);
		@@ -494,7 +540,8 @@ out_reset_timer:
		out:;
		}

		/* Called with BH disabled */
		/* Called with bottom-half processing disabled.
		Called by tcp_write_timer() */
		void tcp_write_timer_handler(struct sock *sk)
		{
		struct inet_connection_sock *icsk = inet_csk(sk);
		@@ -539,7 +586,7 @@ static void tcp_write_timer(unsigned long data)
		if (!sock_owned_by_user(sk)) {
		tcp_write_timer_handler(sk);
		} else {
		/* deleguate our work to tcp_release_cb() */
		/* delegate our work to tcp_release_cb() */
		if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
		sock_hold(sk);
		}