- djm@cvs.openbsd.org 2010/01/30 02:54:53

[openssh.git] / atomicio.c

diff --git a/atomicio.c b/atomicio.c
index 7d9f9340c04d1973541238ad872f9c6c743e38ac..a6b2d127a9b803a8e4e1c85359d351eaaabecaf9 100644 (file)
--- a/atomicio.c
+++ b/atomicio.c
@@ -1,5 +1,8 @@
+/* $OpenBSD: atomicio.c,v 1.25 2007/06/25 12:02:27 dtucker Exp $ */
 /*
- * Copyright (c) 1999 Theo de Raadt
+ * Copyright (c) 2006 Damien Miller. All rights reserved.
+ * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
+ * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -24,35 +27,116 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: atomicio.c,v 1.4 2000/06/20 01:39:37 markus Exp $");
 
-#include "xmalloc.h"
-#include "ssh.h"
+#include <sys/param.h>
+#include <sys/uio.h>
+
+#include <errno.h>
+#ifdef HAVE_POLL_H
+#include <poll.h>
+#else
+# ifdef HAVE_SYS_POLL_H
+#  include <sys/poll.h>
+# endif
+#endif
+#include <string.h>
+#include <unistd.h>
+
+#include "atomicio.h"
 
 /*
- * ensure all of data on socket comes through. f==read || f==write
+ * ensure all of data on socket comes through. f==read || f==vwrite
  */
-ssize_t
-atomicio(f, fd, _s, n)
-       ssize_t (*f) ();
-       int fd;
-       void *_s;
-       size_t n;
+size_t
+atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
 {
        char *s = _s;
-       ssize_t res, pos = 0;
+       size_t pos = 0;
+       ssize_t res;
+       struct pollfd pfd;
 
+       pfd.fd = fd;
+       pfd.events = f == read ? POLLIN : POLLOUT;
        while (n > pos) {
                res = (f) (fd, s + pos, n - pos);
                switch (res) {
                case -1:
-                       if (errno == EINTR || errno == EAGAIN)
+                       if (errno == EINTR)
+                               continue;
+                       if (errno == EAGAIN || errno == EWOULDBLOCK) {
+                               (void)poll(&pfd, 1, -1);
                                continue;
+                       }
+                       return 0;
                case 0:
-                       return (res);
+                       errno = EPIPE;
+                       return pos;
                default:
-                       pos += res;
+                       pos += (size_t)res;
                }
        }
        return (pos);
 }
+
+/*
+ * ensure all of data on socket comes through. f==readv || f==writev
+ */
+size_t
+atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
+    const struct iovec *_iov, int iovcnt)
+{
+       size_t pos = 0, rem;
+       ssize_t res;
+       struct iovec iov_array[IOV_MAX], *iov = iov_array;
+       struct pollfd pfd;
+
+       if (iovcnt > IOV_MAX) {
+               errno = EINVAL;
+               return 0;
+       }
+       /* Make a copy of the iov array because we may modify it below */
+       memcpy(iov, _iov, iovcnt * sizeof(*_iov));
+
+#ifndef BROKEN_READV_COMPARISON
+       pfd.fd = fd;
+       pfd.events = f == readv ? POLLIN : POLLOUT;
+#endif
+       for (; iovcnt > 0 && iov[0].iov_len > 0;) {
+               res = (f) (fd, iov, iovcnt);
+               switch (res) {
+               case -1:
+                       if (errno == EINTR)
+                               continue;
+                       if (errno == EAGAIN || errno == EWOULDBLOCK) {
+#ifndef BROKEN_READV_COMPARISON
+                               (void)poll(&pfd, 1, -1);
+#endif
+                               continue;
+                       }
+                       return 0;
+               case 0:
+                       errno = EPIPE;
+                       return pos;
+               default:
+                       rem = (size_t)res;
+                       pos += rem;
+                       /* skip completed iov entries */
+                       while (iovcnt > 0 && rem >= iov[0].iov_len) {
+                               rem -= iov[0].iov_len;
+                               iov++;
+                               iovcnt--;
+                       }
+                       /* This shouldn't happen... */
+                       if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
+                               errno = EFAULT;
+                               return 0;
+                       }
+                       if (iovcnt == 0)
+                               break;
+                       /* update pointer in partially complete iov */
+                       iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
+                       iov[0].iov_len -= rem;
+               }
+       }
+       return pos;
+}