- djm@cvs.openbsd.org 2006/04/16 00:52:55
[atomicio.c atomicio.h]
introduce atomiciov() function that wraps readv/writev to retry
interrupted transfers like atomicio() does for read/write;
feedback deraadt@ dtucker@ stevesk@ ok deraadt@
diff --git a/atomicio.c b/atomicio.c
index 996beff..de5363a 100644
--- a/atomicio.c
+++ b/atomicio.c
@@ -1,5 +1,6 @@
-/* $OpenBSD: atomicio.c,v 1.17 2006/04/01 05:51:34 djm Exp $ */
+/* $OpenBSD: atomicio.c,v 1.18 2006/04/16 00:52:55 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.
@@ -59,3 +60,55 @@
}
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;
+
+ 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));
+
+ for (; iovcnt > 0 && iov[0].iov_len > 0;) {
+ res = (f) (fd, iov, iovcnt);
+ switch (res) {
+ case -1:
+ if (errno == EINTR || errno == EAGAIN)
+ 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 > iov[0].iov_len || (rem > 0 && iovcnt <= 0)) {
+ 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;
+}