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* FIN_WAIT1 / TCP_CORK / 2.2 -- reproducible bug and test case
@ 2002-09-18  2:03 Martin Pool
  2002-09-18  1:58 ` David S. Miller
  0 siblings, 1 reply; 23+ messages in thread
From: Martin Pool @ 2002-09-18  2:03 UTC (permalink / raw)
  To: davem, ak, kuznet, netdev, Alan.Cox

[-- Attachment #1: Type: text/plain, Size: 902 bytes --]

(Sorry for spamming people directly; my list message didn't get a
reply and it's a serious bug in some circumstances.)

I've discovered a bug in Linux 2.2 that allows TCP sockets to get
stuck in FIN_WAIT1 with no timeout or retransmissions.  Code to
demonstrate the problem, plus  a tcpdump of it happening, is
attached.  There are more details about what's going on, as I
understand it, in the headers.

I suspect there is a mishandling of sk->nonagle==2 in tcp_send_test(),
but I have not yet puzzled out the code enough to say exactly what it
is.  I think basically the handling of a closing socket that still has
corks set is broken.

You might argue that this is a security bug because it allows local
users to consume arbitrarily large (?)  kernel resources, and in some
cases the resources cannot be released without a reboot.  (Or perhaps
a spoofed RST packet would fix it too.)

-- 
Martin 



[-- Attachment #2: corked_demo.c --]
[-- Type: text/x-csrc, Size: 5627 bytes --]

/* -*- c-file-style: "java"; indent-tabs-mode: nil -*-
 *
 * corked_demo.c -- Demonstrate Linux 2.2 bug relating to TCP_CORKED sockets.
 *
 * Written 2002 by Martin Pool <mbp@sourcefrog.net>
 *
 * Build this, run it as root with something like "sudo ./corked_demo
 * SOMEHOST 9" to write to the discard port.  (It needs root access to
 * set SO_DEBUG.)  The other machine must be running the discard
 * service to accept the connection and data.
 *
 * Basically all it does is open a corked connection, and then drop it
 * while there is (possibly) data in the SendQ.  The socket gets
 * "stuck" in FIN_WAIT1 and doesn't seem to be able to flush the last
 * bit of data.
 *
 * If you have an affected version of the kernel, most times this is
 * run run you will get a socket stuck in FIN_WAIT1 state.  It looks
 * like this:
 *
 * tcp        0   3201 maudlin:1048            maudlin:discard         FIN_WAIT1   root       0          -                   off (0.00/0/0)
 *
 * This happens in 2.2.16, .18, and .21.
 *
 * It seems to me that this *has* to be incorrect, because there is
 * data waiting to go out, but no timer running.  The socket stays
 * stuck, chewing up kernel memory forever.
 *
 * Running a hundred iterations gives 36 stuck in this state.
 *
 * On the server the situation is almost as bad: the sockets end up in
 * ESTABLISHED state, but they'll never recieve more data.  Presumably
 * they'll hang around until the server gives up and terminates, or
 * until the TCP 2-hour timeout elapses.  
 *
 * Sometimes killing off the server makes the FIN_WAIT1 sockets go
 * away on the client, but it is not reliable.  However, neither side
 * seems to time out of its own accord -- I left the two machines
 * sitting overnight and all the sockets were still
 * FIN_WAIT1/ESTABLISHED in the morning.
 *
 * tcpdump shows that the FIN is not sent when the client program
 * closes the socket.  However, when the server program is killed, its
 * FIN gets things flowing again.
 *
 * I think that on the system where this was originally seen, both the
 * client and the server used corks, and so killing the server program
 * and closing its socket didn't send a FIN, and therefore things
 * stayed jammed indefinitely.
 *
 * Since this can be provoked with local unprivileged access, and
 * since the sockets apparently can't be cleared up without a reboot,
 * it could be considered a kind of resource exhaustion attack.  If it
 * happens inadvertently, it can cause problems on the server by
 * causing the remote machine to hang until it is killed off. */


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <assert.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <netinet/tcp.h>

#include <netdb.h>


/**
 * Open a socket to a tcp remote host with the specified port.
 *
 * The socket is (if appropriate) corked on return, so that the third
 * handshake should be sent containing useful data.
 *
 * Stolen from rsync via distcc.
 *
 * @todo Don't try for too long to connect. 
 **/
int open_socket_out(const char *host, int port, int *p_fd)
{
    int type = SOCK_STREAM;
    struct sockaddr_in sock_out;
    int fd;
    struct hostent *hp;

    fd = socket(PF_INET, type, 0);
    if (fd == -1) {
	printf("failed to create socket: %s\n", strerror(errno));
	exit(1);
    }

    hp = gethostbyname(host);
    if (!hp) {
	fprintf(stderr, "unknown host: \"%s\"\n", host);
	(void) close(fd);
	exit(1);
    }

    memcpy(&sock_out.sin_addr, hp->h_addr, (size_t) hp->h_length);
    sock_out.sin_port = htons(port);
    sock_out.sin_family = PF_INET;

    if (connect(fd, (struct sockaddr *) &sock_out, (int) sizeof(sock_out))) {
        fprintf(stderr, "failed to connect to %s port %d: %s\n", host, port, 
                     strerror(errno));
	(void) close(fd);
	exit(1);
    }

    printf("client got connection to %s port %d on fd%d\n", host, port, fd);

    *p_fd = fd;
    return 0;
}


/**
 * Stick a TCP cork in the socket.  
 **/
int tcp_cork_sock(int fd, int corked)
{
    if (setsockopt(fd, SOL_TCP, TCP_CORK, &corked, sizeof corked) == -1) {
        fprintf(stderr, "setsockopt(corked=%d) failed: %s\n",
                corked, strerror(errno));
        exit(1);
    }

    printf("%scorked fd%d\n", corked ? "" : "un", fd);

    return 0;
}



int debug_sock(int fd, int debug_on)
{
    if (setsockopt(fd, SOL_SOCKET, SO_DEBUG, &debug_on, sizeof debug_on) == -1) {
        fprintf(stderr, "setsockopt(debug=%d) failed: %s\n",
                debug_on, strerror(errno));
        exit(1);
    }

    printf("%sdebug fd%d\n", debug_on ? "" : "un", fd);

    return 0;
}



int dcc_writex(int fd, const void *buf, size_t len)
{
    ssize_t r;
    
    while (len > 0) {
        r = write(fd, buf, len);
        if (r == -1) {
            fprintf(stderr, "failed to write: %s\n", strerror(errno));
            return -1;
        } else if (r == 0) {
            fprintf(stderr, "unexpected eof on fd%d\n", fd);
            return -1;
        } else {
            buf = &((char *) buf)[r];
            len -= r;
        }
    }

    return 0;
}


int send_junk(int fd)
{
    static char trash[100000];

    return dcc_writex(fd, trash, sizeof trash);
}



int main(int argc, char **argv)
{
    int fd;

    if (argc != 3) {
        fprintf(stderr, "usage: corked_demo HOST NUMERICPORT\n");
        return 1;
    }
    
    open_socket_out(argv[1], atoi(argv[2]), &fd);

    debug_sock(fd, 1);
    tcp_cork_sock(fd, 1);

    send_junk(fd);

    return 0;
}

[-- Attachment #3: corked_tcpdump.txt --]
[-- Type: text/plain, Size: 5257 bytes --]

tcpdump: listening on eth0
04:39:25.336746 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: S 2229455302:2229455302(0) win 16060 <mss 1460,sackOK,timestamp 5592391[|tcp]> (DF)
04:39:25.336913 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: S 3652179257:3652179257(0) ack 2229455303 win 5792 <mss 1460,sackOK,timestamp 352437103[|tcp]> (DF)
04:39:25.337134 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . ack 1 win 16060 <nop,nop,timestamp 5592391 352437103> (DF)
04:39:25.343813 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: P 1:1449(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.344057 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: P 1449:2897(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.344012 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 1449 win 8688 <nop,nop,timestamp 352437103 5592392> (DF)
04:39:25.344160 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 2897 win 11584 <nop,nop,timestamp 352437103 5592392> (DF)
04:39:25.344657 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 2897:4345(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.345093 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 4345:5793(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.345299 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 5793:7241(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.345407 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 7241:8689(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.345059 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 4345 win 14480 <nop,nop,timestamp 352437103 5592392> (DF)
04:39:25.345210 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 5793 win 17376 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.345389 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 7241 win 20272 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.345499 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 8689 win 23168 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.345686 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 8689:10137(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.345880 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 10137:11585(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437103> (DF)
04:39:25.346046 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 11585:13033(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437104> (DF)
04:39:25.346230 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 13033:14481(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437104> (DF)
04:39:25.346424 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 14481:15929(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437104> (DF)
04:39:25.346534 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 15929:17377(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437104> (DF)
04:39:25.346651 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 17377:18825(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437104> (DF)
04:39:25.346759 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . 18825:20273(1448) ack 1 win 16060 <nop,nop,timestamp 5592392 352437104> (DF)
04:39:25.345806 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 10137 win 26064 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.345970 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 11585 win 28960 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.346208 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 13033 win 31856 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.346323 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 14481 win 34752 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.346516 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 15929 win 37648 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.346624 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 17377 win 40544 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.346742 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 18825 win 43440 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.346849 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 20273 win 46336 <nop,nop,timestamp 352437104 5592392> (DF)
04:39:25.347261 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: . ack 21721 win 49232 <nop,nop,timestamp 352437104 5592392> (DF)


(now, kill the server)

04:39:43.795571 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: F 1:1(0) ack 99913 win 63712 <nop,nop,timestamp 352438965 5592393> (DF)
04:39:43.795643 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: . ack 2 win 16060 <nop,nop,timestamp 5594236 352438965> (DF)
04:39:43.795801 maudlin.ozlabs.hp.com.1884 > nevada.aus.hp.com.discard: FP 99913:100001(88) ack 2 win 16060 <nop,nop,timestamp 5594236 352438965> (DF)
04:39:43.795890 nevada.aus.hp.com.discard > maudlin.ozlabs.hp.com.1884: R 3652179259:3652179259(0) win 0 (DF)

36 packets received by filter
0 packets dropped by kernel

[-- Attachment #4: corked-out-20020917-2009 --]
[-- Type: text/plain, Size: 7668 bytes --]

ev: 1.0 
  Type:   Direct-Access                      ANSI SCSI revision: 02
Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
scsi0: Target 0: Queue Depth 28, Asynchronous
scsi : detected 1 SCSI disk total.
SCSI device sda: hdwr sector= 512 bytes. Sectors= 2097152 [1024 MB] [1.0 GB]
pcnet32.c: PCI bios is present, checking for devices...
PCI Master Bit has not been set. Setting...
Found PCnet/PCI at 0x10a0, irq 10.
eth0: PCnet/PCI II 79C970A at 0x10a0, 00 50 56 40 00 52 assigned IRQ 10.
pcnet32.c:v1.25kf 26.9.1999 tsbogend@alpha.franken.de
Partition check:
 sda: sda1 sda2 < sda5 >
IA-32 Microcode Update Driver: v1.08 <tigran@veritas.com>
VFS: Mounted root (ext2 filesystem) readonly.
Freeing unused kernel memory: 60k freed
scsi0: Tagged Queuing now active for Target 0
Adding Swap: 268264k swap-space (priority -1)
tcp_snd_test sk=c7977740, skb=c7a72ac0, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87a40, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87680, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a875e0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a875e0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87540, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87540, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87540, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a874a0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a874a0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a874a0, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87400, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87400, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87400, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87180, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87180, tail=0
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87900, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87900, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a870e0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a870e0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87720, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87720, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87360, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87360, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a875e0, tail=1
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a875e0, tail=1
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a72ac0, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87360, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a870e0, tail=1
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a875e0, tail=1
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87860, tail=1
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87860, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87860, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a872c0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a872c0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87220, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87220, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87220, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87e00, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87e00, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87540, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87540, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a877c0, tail=0
tcp_snd_test skb->flags=0x10, sk->nonagle=2, nagle_check=1
tcp_snd_test returns 1
tcp_snd_test sk=c7977740, skb=c7a87900, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=0
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87900, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=0
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87900, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=0
tcp_snd_test returns 0
tcp_snd_test sk=c7977740, skb=c7a87900, tail=1
tcp_snd_test skb->flags=0x18, sk->nonagle=2, nagle_check=0
tcp_snd_test returns 0

^ permalink raw reply	[flat|nested] 23+ messages in thread
* Re: FIN_WAIT1 / TCP_CORK / 2.2 -- reproducible bug and test case
@ 2002-10-04 15:06 James Morris
  2002-10-04 23:27 ` Martin Pool
  2002-10-05  7:51 ` Martin Pool
  0 siblings, 2 replies; 23+ messages in thread
From: James Morris @ 2002-10-04 15:06 UTC (permalink / raw)
  To: Martin Pool; +Cc: netdev

Martin,

I'm not able to reproduce the bug exactly as described.  What kind of
network connection were you using between the boxes, and what was the
kernel version at the server end?  (I've been testing between two boxes on
a 10Mbps lan, with 2.2.22 at the client side and both 2.2.20 and 2.4.19
kernels at the server side).

I'm seeing what looks like some quite buggy behaviour (which needs 
further analysis), but no long term FIN_WAIT1 states.


- James
-- 
James Morris
<jmorris@intercode.com.au>

^ permalink raw reply	[flat|nested] 23+ messages in thread
end of thread, other threads:[~2002-10-10 16:43 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2002-09-18  2:03 FIN_WAIT1 / TCP_CORK / 2.2 -- reproducible bug and test case Martin Pool
2002-09-18  1:58 ` David S. Miller
2002-09-18  2:09   ` Martin Pool
2002-09-18 23:38     ` Alexey Kuznetsov
2002-09-26  5:47       ` Martin Pool
2002-09-26 13:09         ` kuznet
2002-09-26 20:46           ` David S. Miller
2002-09-30  9:59             ` Martin Pool
2002-09-30 10:32               ` David S. Miller
2002-09-30 12:23               ` Alan Cox
2002-10-03  3:30                 ` James Morris
2002-10-03  3:54                   ` Andi Kleen
2002-10-03  7:59                     ` David S. Miller
2002-10-03  7:56                   ` David S. Miller
2002-09-18  2:30   ` Martin Pool
  -- strict thread matches above, loose matches on Subject: below --
2002-10-04 15:06 James Morris
2002-10-04 23:27 ` Martin Pool
2002-10-05  7:51 ` Martin Pool
2002-10-05 11:53   ` James Morris
2002-10-08 10:21     ` Martin Pool
2002-10-08 10:28       ` James Morris
2002-10-10 16:36     ` James Morris
2002-10-10 16:43       ` James Morris

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