Re: Fw: [Bug 8013] New: select for write hangs on a socket after write returned ECONNRESET

[Evgeniy Polyakov]

On Thu, Feb 15, 2007 at 04:04:05PM -0800, Stephen Hemminger ([EMAIL PROTECTED]) 
wrote:
> Someone want to take a stab at fixing this??

Works for me with attached application - select on connreset socket
immediately returns one ready descriptor.

$ ./a.out 192.168.0.48 22
select: err: 1, errno: 0.
write: err: 128, errno: 0.
select: err: 1, errno: 0.
write: err: 128, errno: 0.
select: err: 1, errno: 0.
write: err: -1, errno: 104.
on exit: select: err: 1, errno: 104.

-- 
        Evgeniy Polyakov

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/poll.h>
#include <sys/sendfile.h>

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

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include <ctype.h>
#include <netdb.h>

#define ulog(f, a...) fprintf(stderr, f, ##a)
#define ulog_err(f, a...) ulog(f ": %s [%d].\n", ##a, strerror(errno), errno)

int main(int argc, char *argv[])
{
        struct hostent *h;
        int s, err;
        char buf[128];
        struct sockaddr_in sa;
        fd_set rfds;
        struct timeval tv;

        if (argc != 3) {
                ulog("Usage: %s <addr> <port>\n", argv[0]);
                return -1;
        }
        
        h = gethostbyname(argv[1]);
        if (!h) {
                ulog_err("%s: Failed to get address of %s.\n", __func__, 
argv[1]);
                return -1;
        }

        s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (s == -1) {
                ulog_err("%s: Failed to create server socket", __func__);
                return -1;
        }
        
        memcpy(&(sa.sin_addr.s_addr), h->h_addr_list[0], 4);
        sa.sin_port = htons(atoi(argv[2]));
        sa.sin_family = AF_INET;

        if (connect(s, (struct sockaddr *)&sa, sizeof(sa))) {
                ulog_err("%s: Failed to connect to %s:%s", __func__, argv[1], 
argv[2]);
                return -1;
        }

        do {
                FD_ZERO(&rfds);
                FD_SET(s, &rfds);

                tv.tv_sec = 500;
                tv.tv_usec = 0;

                err = select(s+1, &rfds, NULL, NULL, &tv);
                ulog("select: err: %d, errno: %d.\n", err, errno);

                err = write(s, buf, sizeof(buf));
                ulog("write: err: %d, errno: %d.\n", err, errno);
        } while (err > 0);

        FD_ZERO(&rfds);
        FD_SET(s, &rfds);

        tv.tv_sec = 500;
        tv.tv_usec = 0;

        err = select(s+1, &rfds, NULL, NULL, &tv);

        ulog("on exit: select: err: %d, errno: %d.\n", err, errno);
}