rewrite iov_send_recv() and move it to iov.c

Make it much more understandable, add a missing
iov_cnt argument (number of iovs in the iov), and
add comments to it.

The new implementation has been extensively tested
by splitting a large buffer into many small
randomly-sized chunks, sending it over socket to
another, slow process and verifying the receiving
data is the same.

Also add a unit test for iov_send_recv(), sending/
receiving data between two processes over a socketpair
using random vectors and random sizes.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

1 files changed, 0 insertions, 83 deletions

diff --git a/cutils.c b/cutils.c
index cb6f63848c..e2bc1b89df 100644
--- a/cutils.c
+++ b/cutils.c
@@ -375,86 +375,3 @@ int qemu_parse_fd(const char *param)
     }
     return fd;
 }
-
-ssize_t iov_send_recv(int sockfd, struct iovec *iov,
-                      size_t offset, size_t bytes,
-                      bool do_sendv)
-{
-    int iovlen;
-    ssize_t ret;
-    size_t diff;
-    struct iovec *last_iov;
-
-    /* last_iov is inclusive, so count from one.  */
-    iovlen = 1;
-    last_iov = iov;
-    bytes += offset;
-
-    while (last_iov->iov_len < bytes) {
-        bytes -= last_iov->iov_len;
-
-        last_iov++;
-        iovlen++;
-    }
-
-    diff = last_iov->iov_len - bytes;
-    last_iov->iov_len -= diff;
-
-    while (iov->iov_len <= offset) {
-        offset -= iov->iov_len;
-
-        iov++;
-        iovlen--;
-    }
-
-    iov->iov_base = (char *) iov->iov_base + offset;
-    iov->iov_len -= offset;
-
-    {
-#if defined CONFIG_IOVEC && defined CONFIG_POSIX
-        struct msghdr msg;
-        memset(&msg, 0, sizeof(msg));
-        msg.msg_iov = iov;
-        msg.msg_iovlen = iovlen;
-
-        do {
-            if (do_sendv) {
-                ret = sendmsg(sockfd, &msg, 0);
-            } else {
-                ret = recvmsg(sockfd, &msg, 0);
-            }
-        } while (ret == -1 && errno == EINTR);
-#else
-        struct iovec *p = iov;
-        ret = 0;
-        while (iovlen > 0) {
-            int rc;
-            if (do_sendv) {
-                rc = send(sockfd, p->iov_base, p->iov_len, 0);
-            } else {
-                rc = qemu_recv(sockfd, p->iov_base, p->iov_len, 0);
-            }
-            if (rc == -1) {
-                if (errno == EINTR) {
-                    continue;
-                }
-                if (ret == 0) {
-                    ret = -1;
-                }
-                break;
-            }
-            if (rc == 0) {
-                break;
-            }
-            ret += rc;
-            iovlen--, p++;
-        }
-#endif
-    }
-
-    /* Undo the changes above */
-    iov->iov_base = (char *) iov->iov_base - offset;
-    iov->iov_len += offset;
-    last_iov->iov_len += diff;
-    return ret;
-}