We use writev because sendmsg can only be used on socket fds.
Signed-off-by: Orit Wasserman <owass...@redhat.com>
---
include/qemu/iov.h | 12 ++++++++++++
util/iov.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+)
diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index 68d25f2..e26b7ba 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -82,6 +82,18 @@ ssize_t iov_send_recv(int sockfd, struct iovec *iov,
unsigned iov_cnt,
#define iov_send(sockfd, iov, iov_cnt, offset, bytes) \
iov_send_recv(sockfd, iov, iov_cnt, offset, bytes, true)
+/*
+ * writes iovcnt buffers of data described by iov to the file associated with
+ * the file descriptor fd.
+ *
+ * @fd - file descriptor
+ * @iov - iov to write
+ * @invcnt - number of buffers to write
+ *
+ * @return - number of bytes return or -1 on error
+ */
+ssize_t iov_writev(int fd, struct iovec *iov, unsigned iov_cnt);
+
/**
* Produce a text hexdump of iovec `iov' with `iov_cnt' number of elements
* in file `fp', prefixing each line with `prefix' and processing not more
diff --git a/util/iov.c b/util/iov.c
index 9dae318..bcd6e97 100644
--- a/util/iov.c
+++ b/util/iov.c
@@ -197,6 +197,42 @@ ssize_t iov_send_recv(int sockfd, struct iovec *iov,
unsigned iov_cnt,
return ret;
}
+ssize_t iov_writev(int fd, struct iovec *iov, unsigned iov_cnt)
+{
+#if defined CONFIG_IOVEC && defined CONFIG_POSIX
+ ssize_t ret;
+
+ do {
+ ret = writev(fd, iov, iov_cnt);
+ } while (ret < 0 && errno == EINTR);
+
+ return ret;
+#else
+ /* else send piece-by-piece */
+ /*XXX Note: windows has WSASend() and WSARecv() */
+ unsigned i = 0;
+ ssize_t ret = 0;
+ while (i < iov_cnt) {
+ ssize_t r = send(fd, iov[i].iov_base, iov[i].iov_len, 0);
+ if (r > 0) {
+ ret += r;
+ } else if (!r) {
+ break;
+ } else if (errno == EINTR) {
+ continue;
+ } else {
+ /* else it is some "other" error,
+ * only return if there was no data processed. */
+ if (ret == 0) {
+ ret = -1;
+ }
+ break;
+ }
+ i++;
+ }
+ return ret;
+#endif
+}
void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt,
FILE *fp, const char *prefix, size_t limit)
--
1.7.11.7
