Date: Sat, 31 May 2008 11:01:45 GMT From: Alexander Pavlov <lup.mail@gmail.com> To: freebsd-gnats-submit@FreeBSD.org Subject: misc/124160: connect() function loops indefinitely Message-ID: <200805311101.m4VB1jU7085071@www.freebsd.org> Resent-Message-ID: <200805311110.m4VBA1pK092766@freefall.freebsd.org>
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>Number: 124160
>Category: misc
>Synopsis: connect() function loops indefinitely
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sat May 31 11:10:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator: Alexander Pavlov
>Release: 6.3-RELEASE
>Organization:
JSC Apriko
>Environment:
FreeBSD torment.skynet 6.3-RELEASE-p1 FreeBSD 6.3-RELEASE-p1 #3: Sun Mar 9 11:59:41 UTC 2008 lup@torment.skynet:/usr/obj/usr/src/sys/CLONED-CORE i386
>Description:
I have a number of Intel platforms running FreeBSD 6.3-Release (using mpd-5.1, ipfw,ipnat).
Under some circumstances, at arbitrary time, my FreeBSD boxes stop responding to connection requests, but still remain up and running, so I can log in locally. In such state, major network functions are not working: I can't launch ngctl - it simply hangs, I can't add static arp entry - arp also hangs, and so on. I do not even see replies to ping 127.0.0.1 requests.
Trying to find clues to this problem, I wrote small program (in attach to this PR), which in normal state gives such output:
=================
inet socket testing..
1 4510 => server: creating listening socket
4510 => server: bind() ok
4510 => server: listen() ok
2 4511 => client: connecting..
4511 => client: socket() ok
4511 => client: trying to connect()..
4511 => client: connect() ok
3 4510 => server: client connected
4 4510 => server: send: "Anybody here?", res=13, errno=0
5 4511 => client: recieved: "Anybody here?", res=13, errno=0
6 4511 => client: send: "I am.", res=256, errno=0
7 4510 => server: recieved: "I am.", res=256, errno=0
=================
While in "hanged" state it gives:
=================
inet socket testing..
1 97262 => server: creating listening socket
97262 => server: bind() ok
97262 => server: listen() ok
2 97263 => client: connecting..
97263 => client: socket() ok
97263 => client: trying to connect()..
=================
and hangs until killed.
>How-To-Repeat:
It's a pity, but I don't know. In my environment it happens almost daily.
>Fix:
Patch attached with submission follows:
#include <stand.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <netinet/in.h>
#define send_str "Anybody here?"
#define answer_str "I am."
#define server_port 631
#define listenq 1024
int main()
{
int sockets[2];
char buf[256];
int pid;
int res;
int listenfd,connfd;
struct sockaddr_in clientaddr,serveraddr;
printf("inet socket testing..\n");
if (fork() != 0) {
printf("1 %d => server: creating listening socket\n",getpid());
listenfd = socket(AF_INET,SOCK_STREAM,0);
if (listenfd<0) printf("%d => server: socket() error: %d\n",getpid(),errno);
bzero(&serveraddr, sizeof(serveraddr));
serveraddr.sin_family = AF_INET;
serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
serveraddr.sin_port = htons(server_port);
res = bind(listenfd,(struct sockaddr *) &serveraddr,sizeof(serveraddr));
if (res<0) {printf("%d => server: bind() error: %d\n",getpid(),errno); } else {printf("%d => server: bind() ok\n",getpid());}
res = listen(listenfd, listenq);
if (res<0) {printf("%d => server: listen() error: %d\n",getpid(),errno);} else {printf("%d => server: listen() ok\n",getpid());}
while (connfd <= 0) {
connfd = accept(listenfd, (struct sockaddr *) NULL, NULL);
if (connfd > 0) printf("3 %d => server: client connected\n",getpid());
res = write(connfd, send_str, strlen(send_str));
printf("4 %d => server: send: \"%s\", res=%d, errno=%d\n",getpid(), send_str,res,errno);
wait(NULL);
res = read(connfd, buf, sizeof(buf));
printf("7 %d => server: recieved: \"%s\", res=%d, errno=%d\n",getpid(), buf,res,errno);
close(connfd);
}
close(listenfd);
exit(0);
} else {
printf("2 %d => client: connecting..\n",getpid());
connfd = socket(AF_INET,SOCK_STREAM,0);
if (connfd<0) {printf("%d => client: socket() error: %d\n",getpid(),errno);} else {printf("%d => client: socket() ok\n",getpid());}
bzero(&serveraddr, sizeof(serveraddr));
serveraddr.sin_family = AF_INET;
inet_pton(AF_INET, "127.0.0.1", &serveraddr.sin_addr);
serveraddr.sin_port = htons(server_port);
printf("%d => client: trying to connect()..\n",getpid());
res = connect(connfd,(struct sockaddr *) &serveraddr,sizeof(serveraddr));
if (res<0) {printf("%d => client: connect() error: %d\n",getpid(),errno);} else {printf("%d => client: connect() ok\n",getpid());}
res = read(connfd, buf, sizeof(buf));
printf("5 %d => client: recieved: \"%s\", res=%d, errno=%d\n",getpid(), buf,res,errno);
res = write(connfd, answer_str, sizeof(buf));
printf("6 %d => client: send: \"%s\", res=%d, errno=%d\n",getpid(), answer_str,res,errno);
close(connfd);
exit(0);
}
return(0);
}
>Release-Note:
>Audit-Trail:
>Unformatted:
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