URecvfrom.c

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#include "syshdrs.h"
 
#if !defined(NO_UNIX_DOMAIN_SOCKETS) && !defined(NO_SIGNALS)
 
extern volatile Sjmp_buf gNetTimeoutJmp;
extern volatile Sjmp_buf gPipeJmp;
 
int
URecvfrom(int sfd, char *const buf, size_t size, int fl, struct sockaddr_un *const fromAddr, int *ualen, int tlen)
{
    int nread, tleft;
    vsio_sigproc_t sigalrm, sigpipe;
    time_t done, now;
 
    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 {
        *ualen = sizeof(struct sockaddr_un);
        (void) alarm((unsigned int) tleft);
        nread = recvfrom(sfd, buf, size, fl,
            (struct sockaddr *) fromAddr, ualen);
        (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);
}   /* URecvfrom */
 
#endif