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-rw-r--r--atomicio.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/atomicio.c b/atomicio.c
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+/* $OpenBSD: atomicio.c,v 1.28 2016/07/27 23:18:12 djm Exp $ */
+/*
+ * 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
+ * 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.
+ */
+
+#include "includes.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 <limits.h>
+
+#include "atomicio.h"
+
+/*
+ * ensure all of data on socket comes through. f==read || f==vwrite
+ */
+size_t
+atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
+ int (*cb)(void *, size_t), void *cb_arg)
+{
+ char *s = _s;
+ size_t pos = 0;
+ ssize_t res;
+ struct pollfd pfd;
+
+#ifndef BROKEN_READ_COMPARISON
+ pfd.fd = fd;
+ pfd.events = f == read ? POLLIN : POLLOUT;
+#endif
+ while (n > pos) {
+ res = (f) (fd, s + pos, n - pos);
+ switch (res) {
+ case -1:
+ if (errno == EINTR)
+ continue;
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+#ifndef BROKEN_READ_COMPARISON
+ (void)poll(&pfd, 1, -1);
+#endif
+ continue;
+ }
+ return 0;
+ case 0:
+ errno = EPIPE;
+ return pos;
+ default:
+ pos += (size_t)res;
+ if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
+ errno = EINTR;
+ return pos;
+ }
+ }
+ }
+ return pos;
+}
+
+size_t
+atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
+{
+ return atomicio6(f, fd, _s, n, NULL, NULL);
+}
+
+/*
+ * ensure all of data on socket comes through. f==readv || f==writev
+ */
+size_t
+atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
+ const struct iovec *_iov, int iovcnt,
+ int (*cb)(void *, size_t), void *cb_arg)
+{
+ size_t pos = 0, rem;
+ ssize_t res;
+ struct iovec iov_array[IOV_MAX], *iov = iov_array;
+ struct pollfd pfd;
+
+ if (iovcnt < 0 || iovcnt > IOV_MAX) {
+ errno = EINVAL;
+ return 0;
+ }
+ /* Make a copy of the iov array because we may modify it below */
+ memcpy(iov, _iov, (size_t)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;
+ }
+ if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
+ errno = EINTR;
+ return pos;
+ }
+ }
+ return pos;
+}
+
+size_t
+atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
+ const struct iovec *_iov, int iovcnt)
+{
+ return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
+}