atomicio.c

/*
 * Copied from OpenSSH 3.6.1p2.
 *
 * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* RCSID("OpenBSD: atomicio.c,v 1.10 2001/05/08 22:48:07 markus Exp "); */

#include "atomicio.h"

/*
 * ensure all of data on socket comes through. f==read || f==write
 */
ssize_t atomicio(f, fd, _s, n) ssize_t (*f)();
int fd;
void *_s;
size_t n;
{
  char *s = _s;
  ssize_t res;
  size_t pos = 0;

  while (n > pos) {
    res = (f)(fd, s + pos, n - pos);
    switch (res) {
      case -1:
#ifdef EWOULDBLOCK
        if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
#else
        if (errno == EINTR || errno == EAGAIN)
#endif
          continue;
      /* FALLTHROUGH */
      case 0:
        return (res);
      default:
        pos += res;
    }
  }
  return (pos);
}