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The LITMUS^RT kernel.

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author	Thomas Gleixner <tglx@linutronix.de>	2010-09-28 10:18:39 -0400
committer	Thomas Gleixner <tglx@linutronix.de>	2010-10-12 10:53:37 -0400
commit	d0fbca8f9304d1760fdc906b35b06e89fbdbb51f (patch)
tree	4f831294a9cd4d2f46298c45fccfc57a942f04f0 /fs/lockd/xdr4.c
parent	90297c5fe71d32a2a0ead38bd8f6b1112a2e5ac0 (diff)

x86: ioapic/hpet: Convert to new chip functions

Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>

Diffstat (limited to 'fs/lockd/xdr4.c')

0 files changed, 0 insertions, 0 deletions

or Linus Torvalds <torvalds@ppc970.osdl.org> 2005-04-16 18:20:36 -0400 committer Linus Torvalds <torvalds@ppc970.osdl.org> 2005-04-16 18:20:36 -0400 Linux-2.6.12-rc2' href='/cgit/cgit.cgi/litmus-rt-ext-res.git/commit/net/ipv4/tcp_minisocks.c?id=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2'>1da177e4c3f4

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/*
 * 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.
 *
 *		Implementation of the Transmission Control Protocol(TCP).
 *
 * Authors:	Ross Biro
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Mark Evans, <evansmp@uhura.aston.ac.uk>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche, <flla@stud.uni-sb.de>
 *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
 *		Linus Torvalds, <torvalds@cs.helsinki.fi>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Matthew Dillon, <dillon@apollo.west.oic.com>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *		Jorge Cwik, <jorge@laser.satlink.net>
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/workqueue.h>
#include <net/tcp.h>
#include <net/inet_common.h>
#include <net/xfrm.h>

int sysctl_tcp_syncookies __read_mostly = 1;
EXPORT_SYMBOL(sysctl_tcp_syncookies);

int sysctl_tcp_abort_on_overflow __read_mostly;

struct inet_timewait_death_row tcp_death_row = {
	.sysctl_max_tw_buckets = NR_FILE * 2,
	.period		= TCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
	.death_lock	= __SPIN_LOCK_UNLOCKED(tcp_death_row.death_lock),
	.hashinfo	= &tcp_hashinfo,
	.tw_timer	= TIMER_INITIALIZER(inet_twdr_hangman, 0,
					    (unsigned long)&tcp_death_row),
	.twkill_work	= __WORK_INITIALIZER(tcp_death_row.twkill_work,
					     inet_twdr_twkill_work),
/* Short-time timewait calendar */

	.twcal_hand	= -1,
	.twcal_timer	= TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
					    (unsigned long)&tcp_death_row),
};
EXPORT_SYMBOL_GPL(tcp_death_row);

static bool tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win)
{
	if (seq == s_win)
		return true;
	if (after(end_seq, s_win) && before(seq, e_win))
		return true;
	return seq == e_win && seq == end_seq;
}

/*
 * * Main purpose of TIME-WAIT state is to close connection gracefully,
 *   when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
 *   (and, probably, tail of data) and one or more our ACKs are lost.
 * * What is TIME-WAIT timeout? It is associated with maximal packet
 *   lifetime in the internet, which results in wrong conclusion, that
 *   it is set to catch "old duplicate segments" wandering out of their path.
 *   It is not quite correct. This timeout is calculated so that it exceeds
 *   maximal retransmission timeout enough to allow to lose one (or more)
 *   segments sent by peer and our ACKs. This time may be calculated from RTO.
 * * When TIME-WAIT socket receives RST, it means that another end
 *   finally closed and we are allowed to kill TIME-WAIT too.
 * * Second purpose of TIME-WAIT is catching old duplicate segments.
 *   Well, certainly it is pure paranoia, but if we load TIME-WAIT
 *   with this semantics, we MUST NOT kill TIME-WAIT state with RSTs.
 * * If we invented some more clever way to catch duplicates
 *   (f.e. based on PAWS), we could truncate TIME-WAIT to several RTOs.
 *
 * The algorithm below is based on FORMAL INTERPRETATION of RFCs.
 * When you compare it to RFCs, please, read section SEGMENT ARRIVES
 * from the very beginning.
 *
 * NOTE. With recycling (and later with fin-wait-2) TW bucket
 * is _not_ stateless. It means, that strictly speaking we must
 * spinlock it. I do not want! Well, probability of misbehaviour
 * is ridiculously low and, seems, we could use some mb() tricks
 * to avoid misread sequence numbers, states etc.  --ANK
 */
enum tcp_tw_status
tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
			   const struct tcphdr *th)
{
	struct tcp_options_received tmp_opt;
	const u8 *hash_location;
	struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
	bool paws_reject = false;

	tmp_opt.saw_tstamp = 0;
	if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
		tcp_parse_options(skb, &tmp_opt, &hash_location, 0, NULL);

		if (tmp_opt.saw_tstamp) {
			tmp_opt.ts_recent	= tcptw->tw_ts_recent;
			tmp_opt.ts_recent_stamp	= tcptw->tw_ts_recent_stamp;
			paws_reject = tcp_paws_reject(&tmp_opt, th->rst);
		}
	}

	if (tw->tw_substate == TCP_FIN_WAIT2) {
		/* Just repeat all the checks of tcp_rcv_state_process() */

		/* Out of window, send ACK */
		if (paws_reject ||
		    !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
				   tcptw->tw_rcv_nxt,
				   tcptw->tw_rcv_nxt + tcptw->tw_rcv_wnd))
			return TCP_TW_ACK;

		if (th->rst)
			goto kill;

		if (th->syn && !before(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt))
			goto kill_with_rst;

		/* Dup ACK? */
		if (!th->ack ||
		    !after(TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt) ||
		    TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) {
			inet_twsk_put(tw);
			return TCP_TW_SUCCESS;
		}

		/* New data or FIN. If new data arrive after half-duplex close,
		 * reset.
		 */
		if (!th->fin ||
		    TCP_SKB_CB(skb)->end_seq != tcptw->tw_rcv_nxt + 1) {
kill_with_rst:
			inet_twsk_deschedule(tw, &tcp_death_row);
			inet_twsk_put(tw);
			return TCP_TW_RST;
		}

		/* FIN arrived, enter true time-wait state. */
		tw->tw_substate	  = TCP_TIME_WAIT;
		tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
		if (tmp_opt.saw_tstamp) {
			tcptw->tw_ts_recent_stamp = get_seconds();
			tcptw->tw_ts_recent	  = tmp_opt.rcv_tsval;
		}

		if (tcp_death_row.sysctl_tw_recycle &&
		    tcptw->tw_ts_recent_stamp &&
		    tcp_tw_remember_stamp(tw))
			inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout,
					   TCP_TIMEWAIT_LEN);
		else
			inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
					   TCP_TIMEWAIT_LEN);
		return TCP_TW_ACK;
	}

	/*
	 *	Now real TIME-WAIT state.
	 *
	 *	RFC 1122:
	 *	"When a connection is [...] on TIME-WAIT state [...]
	 *	[a TCP] MAY accept a new SYN from the remote TCP to
	 *	reopen the connection directly, if it:
	 *
	 *	(1)  assigns its initial sequence number for the new
	 *	connection to be larger than the largest sequence
	 *	number it used on the previous connection incarnation,
	 *	and
	 *
	 *	(2)  returns to TIME-WAIT state if the SYN turns out
	 *	to be an old duplicate".
	 */

	if (!paws_reject &&
	    (TCP_SKB_CB(skb)->seq == tcptw->tw_rcv_nxt &&
	     (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq || th->rst))) {
		/* In window segment, it may be only reset or bare ack. */

		if (th->rst) {
			/* This is TIME_WAIT assassination, in two flavors.
			 * Oh well... nobody has a sufficient solution to this
			 * protocol bug yet.
			 */
			if (sysctl_tcp_rfc1337 == 0) {
kill:


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