SClose.c

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#include "syshdrs.h"

#ifndef NO_SIGNALS
extern volatile Sjmp_buf gNetTimeoutJmp;
extern volatile Sjmp_buf gPipeJmp;
#endif

int
SClose(int sfd, int tlen)
{
#ifndef NO_SIGNALS
    vsio_sigproc_t sigalrm, sigpipe;

    if (sfd < 0) {
        errno = EBADF;
        return (-1);
    }

    if (tlen < 1) {
        /* Don't time it, shut it down now. */
        if (SetSocketLinger(sfd, 0, 0) == 0) {
            /* Linger disabled, so close()
             * should not block.
             */
            return (closesocket(sfd));
        } else {
            /* This will result in a fd leak,
             * but it's either that or hang forever.
             */
            return (shutdown(sfd, 2));
        }
    }

    if (SSetjmp(gNetTimeoutJmp) != 0) {
        alarm(0);
        (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
        (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
        if (SetSocketLinger(sfd, 0, 0) == 0) {
            /* Linger disabled, so close()
             * should not block.
             */
            return closesocket(sfd);
        } else {
            /* This will result in a fd leak,
             * but it's either that or hang forever.
             */
            (void) shutdown(sfd, 2);
        }
        return (-1);
    }

    sigalrm = (vsio_sigproc_t) SSignal(SIGALRM, SIOHandler);
    sigpipe = (vsio_sigproc_t) SSignal(SIGPIPE, SIG_IGN);

    alarm((unsigned int) tlen);
    for (;;) {
        if (closesocket(sfd) == 0) {
            errno = 0;
            break;
        }
        if (errno != EINTR)
            break;
    }
    alarm(0);
    (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);

    if ((errno != 0) && (errno != EBADF)) {
        if (SetSocketLinger(sfd, 0, 0) == 0) {
            /* Linger disabled, so close()
             * should not block.
             */
            (void) closesocket(sfd);
        } else {
            /* This will result in a fd leak,
             * but it's either that or hang forever.
             */
            (void) shutdown(sfd, 2);
        }
    }
    (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);

    return ((errno == 0) ? 0 : (-1));
#else
    struct timeval tv;
    int result;
    time_t done, now;
    fd_set ss;

    if (sfd < 0) {
        errno = EBADF;
        return (-1);
    }

    if (tlen < 1) {
        /* Don't time it, shut it down now. */
        if (SetSocketLinger(sfd, 0, 0) == 0) {
            /* Linger disabled, so close()
             * should not block.
             */
            return (closesocket(sfd));
        } else {
            /* This will result in a fd leak,
             * but it's either that or hang forever.
             */
            return (shutdown(sfd, 2));
        }
    }

    /* Wait until the socket is ready for writing (usually easy). */
    time(&now);
    done = now + tlen;

    forever {
        tlen = done - now;
        if (tlen <= 0) {
            /* timeout */
            if (SetSocketLinger(sfd, 0, 0) == 0) {
                /* Linger disabled, so close()
                 * should not block.
                 */
                (void) closesocket(sfd);
            } else {
                /* This will result in a fd leak,
                 * but it's either that or hang forever.
                 */
                (void) shutdown(sfd, 2);
            }
            errno = ETIMEDOUT;
            return (kTimeoutErr);
        }

        errno = 0;
        FD_ZERO(&ss);
        FD_SET(sfd, &ss);
        tv.tv_sec = tlen;
        tv.tv_usec = 0;
        result = select(sfd + 1, NULL, SELECT_TYPE_ARG234 &ss, NULL, SELECT_TYPE_ARG5 &tv);
        if (result == 1) {
            /* ready */
            break;
        } else if (result == 0) {
            /* timeout */
            if (SetSocketLinger(sfd, 0, 0) == 0) {
                /* Linger disabled, so close()
                 * should not block.
                 */
                (void) closesocket(sfd);
            } else {
                /* This will result in a fd leak,
                 * but it's either that or hang forever.
                 */
                (void) shutdown(sfd, 2);
            }
            errno = ETIMEDOUT;
            return (kTimeoutErr);
        } else if (errno != EINTR) {
            /* Error, done. This end may have been shutdown. */
            break;
        }
        time(&now);
    }

    /* Wait until the socket is ready for reading. */
    forever {
        tlen = done - now;
        if (tlen <= 0) {
            /* timeout */
            if (SetSocketLinger(sfd, 0, 0) == 0) {
                /* Linger disabled, so close()
                 * should not block.
                 */
                (void) closesocket(sfd);
            } else {
                /* This will result in a fd leak,
                 * but it's either that or hang forever.
                 */
                (void) shutdown(sfd, 2);
            }
            errno = ETIMEDOUT;
            return (kTimeoutErr);
        }

        errno = 0;
        FD_ZERO(&ss);
        FD_SET(sfd, &ss);
        tv.tv_sec = tlen;
        tv.tv_usec = 0;
        result = select(sfd + 1, SELECT_TYPE_ARG234 &ss, NULL, NULL, SELECT_TYPE_ARG5 &tv);
        if (result == 1) {
            /* ready */
            break;
        } else if (result == 0) {
            /* timeout */
            if (SetSocketLinger(sfd, 0, 0) == 0) {
                /* Linger disabled, so close()
                 * should not block.
                 */
                (void) closesocket(sfd);
            } else {
                /* This will result in a fd leak,
                 * but it's either that or hang forever.
                 */
                (void) shutdown(sfd, 2);
            }
            errno = ETIMEDOUT;
            return (kTimeoutErr);
        } else if (errno != EINTR) {
            /* Error, done. This end may have been shutdown. */
            break;
        }
        time(&now);
    }

    /* If we get here, close() won't block. */
    return closesocket(sfd);
#endif
}   /* SClose */