SRecvfrom.c

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#include "syshdrs.h"
 
#ifndef NO_SIGNALS
extern volatile Sjmp_buf gNetTimeoutJmp;
extern volatile Sjmp_buf gPipeJmp;
#endif
 
#ifndef NO_SIGNALS
 
int
SRecvfrom(int sfd, char *const buf, size_t size, int fl, struct sockaddr_in *const fromAddr, int tlen)
{
    int nread, tleft;
    vsio_sigproc_t sigalrm, sigpipe;
    time_t done, now;
    int alen;
 
    if (SSetjmp(gNetTimeoutJmp) != 0) {
        alarm(0);
        (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
        (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
        errno = ETIMEDOUT;
        return (kTimeoutErr);
    }
 
    if (SSetjmp(gPipeJmp) != 0) {
        alarm(0);
        (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
        (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
        errno = EPIPE;
        return (kBrokenPipeErr);
    }
 
    sigalrm = (vsio_sigproc_t) SSignal(SIGALRM, SIOHandler);
    sigpipe = (vsio_sigproc_t) SSignal(SIGPIPE, SIOHandler);
 
    time(&now);
    done = now + tlen;
    tleft = (int) (done - now);
    forever {
        alen = sizeof(struct sockaddr_in);
        (void) alarm((unsigned int) tleft);
        nread = recvfrom(sfd, buf, size, fl,
            (struct sockaddr *) fromAddr, &alen);
        (void) alarm(0);
        if (nread >= 0)
            break;
        if (errno != EINTR)
            break;      /* Fatal error. */
        errno = 0;
        time(&now);
        tleft = (int) (done - now);
        if (tleft < 1) {
            nread = kTimeoutErr;
            errno = ETIMEDOUT;
            break;
        }
    }
 
    (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
    (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
 
    return (nread);
}   /* SRecvfrom */
 
#else
 
int
SRecvfrom(int sfd, char *const buf, size_t size, int fl, struct sockaddr_in *const fromAddr, int tlen)
{
    int nread, tleft;
    fd_set ss;
    struct timeval tv;
    int result;
    time_t done, now;
    int alen;
 
    time(&now);
    done = now + tlen;
    tleft = (int) (done - now);
    nread = 0;
    forever {
        alen = sizeof(struct sockaddr_in);
 
        forever {
            errno = 0;
            FD_ZERO(&ss);
            FD_SET(sfd, &ss);
            tv.tv_sec = tleft;
            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 */
                errno = ETIMEDOUT;
                SETWSATIMEOUTERR
                return (kTimeoutErr);
            } else if (errno != EINTR) {
                return (-1);
            }
        }
 
        nread = recvfrom(sfd, buf, size, fl,
            (struct sockaddr *) fromAddr, &alen);
 
        if (nread >= 0)
            break;
        if (errno != EINTR)
            break;      /* Fatal error. */
        errno = 0;
        time(&now);
        tleft = (int) (done - now);
        if (tleft < 1) {
            nread = kTimeoutErr;
            errno = ETIMEDOUT;
            SETWSATIMEOUTERR
            break;
        }
    }
 
    return (nread);
}   /* SRecvfrom */
 
#endif