Initial source

1 files changed, 329 insertions, 0 deletions

diff --git a/i386/i386at/gpl/linux/include/net/tcp.h b/i386/i386at/gpl/linux/include/net/tcp.h
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+++ b/i386/i386at/gpl/linux/include/net/tcp.h
@@ -0,0 +1,329 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Definitions for the TCP module.
+ *
+ * Version:	@(#)tcp.h	1.0.5	05/23/93
+ *
+ * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#ifndef _TCP_H
+#define _TCP_H
+
+#include <linux/tcp.h>
+#include <net/checksum.h>
+
+#define MAX_SYN_SIZE	44 + MAX_HEADER + 15
+#define MAX_FIN_SIZE	40 + MAX_HEADER + 15
+#define MAX_ACK_SIZE	40 + MAX_HEADER + 15
+#define MAX_RESET_SIZE	40 + MAX_HEADER + 15
+#define MAX_WINDOW	32767		/* Never offer a window over 32767 without using
+					   window scaling (not yet supported). Some poor
+					   stacks do signed 16bit maths! */
+#define MIN_WINDOW	2048
+#define MAX_ACK_BACKLOG	2
+#define MIN_WRITE_SPACE	2048
+#define TCP_WINDOW_DIFF	2048
+
+/* urg_data states */
+#define URG_VALID	0x0100
+#define URG_NOTYET	0x0200
+#define URG_READ	0x0400
+
+#define TCP_RETR1	7	/*
+				 * This is how many retries it does before it
+				 * tries to figure out if the gateway is
+				 * down.
+				 */
+
+#define TCP_RETR2	15	/*
+				 * This should take at least
+				 * 90 minutes to time out.
+				 */
+
+#define TCP_TIMEOUT_LEN	(15*60*HZ) /* should be about 15 mins		*/
+#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to successfully 
+				  * close the socket, about 60 seconds	*/
+#define TCP_FIN_TIMEOUT (3*60*HZ) /* BSD style FIN_WAIT2 deadlock breaker */				  
+#define TCP_ACK_TIME	(3*HZ)	/* time to delay before sending an ACK	*/
+#define TCP_DONE_TIME	(5*HZ/2)/* maximum time to wait before actually
+				 * destroying a socket			*/
+#define TCP_WRITE_TIME	(30*HZ)	/* initial time to wait for an ACK,
+			         * after last transmit			*/
+#define TCP_TIMEOUT_INIT (3*HZ)	/* RFC 1122 initial timeout value	*/
+#define TCP_SYN_RETRIES	 10	/* number of times to retry opening a
+				 * connection 	(TCP_RETR2-....)	*/
+#define TCP_PROBEWAIT_LEN (1*HZ)/* time to wait between probes when
+				 * I've got something to write and
+				 * there is no window			*/
+
+#define TCP_NO_CHECK	0	/* turn to one if you want the default
+				 * to be no checksum			*/
+
+
+/*
+ *	TCP option
+ */
+ 
+#define TCPOPT_NOP		1	/* Padding */
+#define TCPOPT_EOL		0	/* End of options */
+#define TCPOPT_MSS		2	/* Segment size negotiating */
+/*
+ *	We don't use these yet, but they are for PAWS and big windows
+ */
+#define TCPOPT_WINDOW		3	/* Window scaling */
+#define TCPOPT_TIMESTAMP	8	/* Better RTT estimations/PAWS */
+
+
+/*
+ * The next routines deal with comparing 32 bit unsigned ints
+ * and worry about wraparound (automatic with unsigned arithmetic).
+ */
+
+extern __inline int before(__u32 seq1, __u32 seq2)
+{
+        return (__s32)(seq1-seq2) < 0;
+}
+
+extern __inline int after(__u32 seq1, __u32 seq2)
+{
+	return (__s32)(seq2-seq1) < 0;
+}
+
+
+/* is s2<=s1<=s3 ? */
+extern __inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
+{
+	return (after(seq1+1, seq2) && before(seq1, seq3+1));
+}
+
+static __inline__ int min(unsigned int a, unsigned int b)
+{
+	if (a < b) 
+		return(a);
+	return(b);
+}
+
+extern struct proto tcp_prot;
+extern struct tcp_mib tcp_statistics;
+extern struct wait_queue *master_select_wakeup;
+
+extern void	tcp_err(int type, int code, unsigned char *header, __u32 daddr,
+			__u32, struct inet_protocol *protocol);
+extern void	tcp_shutdown (struct sock *sk, int how);
+extern int	tcp_rcv(struct sk_buff *skb, struct device *dev,
+			struct options *opt, __u32 daddr,
+			unsigned short len, __u32 saddr, int redo,
+			struct inet_protocol *protocol);
+
+extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
+
+extern void tcp_read_wakeup(struct sock *);
+extern void tcp_write_xmit(struct sock *);
+extern void tcp_time_wait(struct sock *);
+extern void tcp_retransmit(struct sock *, int);
+extern void tcp_do_retransmit(struct sock *, int);
+extern void tcp_send_check(struct tcphdr *th, unsigned long saddr, 
+		unsigned long daddr, int len, struct sk_buff *skb);
+
+/* tcp_output.c */
+
+extern void tcp_send_probe0(struct sock *);
+extern void tcp_send_partial(struct sock *);
+extern void tcp_write_wakeup(struct sock *);
+extern void tcp_send_fin(struct sock *sk);
+extern void tcp_send_synack(struct sock *, struct sock *, struct sk_buff *);
+extern void tcp_send_skb(struct sock *, struct sk_buff *);
+extern void tcp_send_ack(u32, u32, struct sock *sk, struct tcphdr *th, u32);
+extern void tcp_send_reset(unsigned long saddr, unsigned long daddr, struct tcphdr *th,
+	  struct proto *prot, struct options *opt, struct device *dev, int tos, int ttl);
+
+extern void tcp_enqueue_partial(struct sk_buff *, struct sock *);
+extern struct sk_buff * tcp_dequeue_partial(struct sock *);
+
+/* tcp_input.c */
+extern void tcp_cache_zap(void);
+
+/* tcp_timer.c */
+#define     tcp_reset_msl_timer(x,y,z)	reset_timer(x,y,z)
+extern void tcp_reset_xmit_timer(struct sock *, int, unsigned long);
+extern void tcp_retransmit_timer(unsigned long);
+
+/*
+ *	Default sequence number picking algorithm.
+ *	As close as possible to RFC 793, which
+ *	suggests using a 250kHz clock.
+ *	Further reading shows this assumes 2MB/s networks.
+ *	For 10MB/s ethernet, a 1MHz clock is appropriate.
+ *	That's funny, Linux has one built in!  Use it!
+ */
+
+static inline u32 tcp_init_seq(void)
+{
+	struct timeval tv;
+	do_gettimeofday(&tv);
+	return tv.tv_usec+tv.tv_sec*1000000;
+}
+
+/*
+ *      This function returns the amount that we can raise the
+ *      usable window based on the following constraints
+ *  
+ *	1. The window can never be shrunk once it is offered (RFC 793)
+ *	2. We limit memory per socket
+ */
+
+static __inline__ unsigned short tcp_raise_window(struct sock *sk)
+{
+	long free_space = sock_rspace(sk);
+	long window;
+
+	if (free_space > 1024)
+		free_space &= ~0x3FF; /* make free space a multiple of 1024 */
+
+	if(sk->window_clamp)
+		free_space = min(sk->window_clamp, free_space);
+ 
+	/* 
+         * compute the actual window i.e. 
+         * old_window - received_bytes_on_that_win 
+	 */
+
+	window = sk->window - (sk->acked_seq - sk->lastwin_seq);
+
+	if (sk->mss == 0)
+		sk->mss = sk->mtu;
+ 
+	if ( window < 0 ) {	
+		window = 0;
+		printk(KERN_DEBUG "TRW: win < 0 w=%d 1=%u 2=%u\n", 
+		       sk->window, sk->acked_seq, sk->lastwin_seq);
+	}
+	
+	if ( (free_space - window) >= min(sk->mss, MAX_WINDOW/2) )
+		return ((free_space - window) / sk->mss) * sk->mss;
+
+	return 0;
+}
+
+static __inline__ unsigned short tcp_select_window(struct sock *sk)
+{
+	long free_space = sock_rspace(sk);
+	long window;
+
+	if (free_space > 1024)
+		free_space &= ~0x3FF;	/* make free space a multiple of 1024 */
+
+	if (sk->window_clamp)
+		free_space = min(sk->window_clamp, free_space);
+	
+	/*
+	 * compute the actual window i.e.
+	 * old_window - received_bytes_on_that_win
+	 */
+
+	if (sk->mss == 0)
+		sk->mss = sk->mtu;
+
+	window = sk->window - (sk->acked_seq - sk->lastwin_seq);
+
+	if ( window < 0 ) {
+		window = 0;
+		printk(KERN_DEBUG "TSW: win < 0 w=%d 1=%u 2=%u\n",
+			sk->window, sk->acked_seq, sk->lastwin_seq);
+	}
+
+	/*
+	 * RFC 1122:
+	 * "the suggested [SWS] avoidance algoritm for the receiver is to keep
+	 *  RECV.NEXT + RCV.WIN fixed until:
+	 *  RCV.BUFF - RCV.USER - RCV.WINDOW >= min(1/2 RCV.BUFF, MSS)"
+	 *
+	 * i.e. don't raise the right edge of the window until you can't raise
+	 * it MSS bytes
+	 */
+
+	if ( (free_space - window) >= min(sk->mss, MAX_WINDOW/2) )
+		window += ((free_space - window) / sk->mss) * sk->mss;
+
+	sk->window = window;
+	sk->lastwin_seq = sk->acked_seq;
+
+	return sk->window;
+}
+
+/*
+ * List all states of a TCP socket that can be viewed as a "connected"
+ * state.  This now includes TCP_SYN_RECV, although I am not yet fully
+ * convinced that this is the solution for the 'getpeername(2)'
+ * problem. Thanks to Stephen A. Wood <saw@cebaf.gov>  -FvK
+ */
+
+extern __inline const int tcp_connected(const int state)
+{
+  return(state == TCP_ESTABLISHED || state == TCP_CLOSE_WAIT ||
+	 state == TCP_FIN_WAIT1   || state == TCP_FIN_WAIT2 ||
+	 state == TCP_SYN_RECV);
+}
+
+/*
+ * Calculate(/check) TCP checksum
+ */
+static __inline__ u16 tcp_check(struct tcphdr *th, int len,
+	unsigned long saddr, unsigned long daddr, unsigned long base)
+{
+	return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
+}
+
+#undef STATE_TRACE
+
+#ifdef STATE_TRACE
+static char *statename[]={
+	"Unused","Established","Syn Sent","Syn Recv",
+	"Fin Wait 1","Fin Wait 2","Time Wait", "Close",
+	"Close Wait","Last ACK","Listen","Closing"
+};
+#endif
+
+static __inline__ void tcp_set_state(struct sock *sk, int state)
+{
+	int oldstate = sk->state;
+
+	sk->state = state;
+
+#ifdef STATE_TRACE
+	if(sk->debug)
+		printk("TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
+#endif	
+
+	switch (state) {
+	case TCP_ESTABLISHED:
+		if (oldstate != TCP_ESTABLISHED) {
+			tcp_statistics.TcpCurrEstab++;
+			/* This is a hack but it doesn't occur often and it's going to
+			   be a real        to fix nicely */
+			if (oldstate == TCP_SYN_RECV)
+				wake_up_interruptible(&master_select_wakeup);
+		}
+		break;
+
+	case TCP_CLOSE:
+		tcp_cache_zap();
+		/* Should be about 2 rtt's */
+   		reset_timer(sk, TIME_DONE, min(sk->rtt * 2, TCP_DONE_TIME));
+		/* fall through */
+	default:
+		if (oldstate==TCP_ESTABLISHED)
+			tcp_statistics.TcpCurrEstab--;
+	}
+}
+
+#endif	/* _TCP_H */