s3:unix_msg: use an iov in unix_dgram_msg/queue_msg instead of buffer and length

This is equivalent, reads more easily and makes extraction
more obvious.

Pair-Programmed-With: Volker Lendecke <vl@samba.org>
Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Michael Adam <obnox@samba.org>
Signed-off-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>

diff --git a/source3/lib/unix_msg/unix_msg.c b/source3/lib/unix_msg/unix_msg.c
index dca2ab151b9bf94ca6d6c43ba45c2bb373460938..872657577768da12bfa4de063e6ca0dff71d3c1b 100644 (file)
--- a/source3/lib/unix_msg/unix_msg.c
+++ b/source3/lib/unix_msg/unix_msg.c
@@ -44,8 +44,7 @@ struct unix_dgram_msg {
        int sys_errno;
        size_t num_fds;
        int *fds;
-       size_t buflen;
-       uint8_t buf[];
+       struct iovec iov;
 };
 
 struct unix_dgram_send_queue {
@@ -480,7 +479,8 @@ static int queue_msg(struct unix_dgram_send_queue *q,
                goto invalid;
        }
 
-       msglen = offsetof(struct unix_dgram_msg, buf);
+       msglen = sizeof(struct unix_dgram_msg);
+
        tmp = msglen + data_len;
        if ((tmp < msglen) || (tmp < data_len)) {
                /* overflow */
@@ -514,10 +514,16 @@ static int queue_msg(struct unix_dgram_send_queue *q,
                ret = ENOMEM;
                goto fail;
        }
-       msg->buflen = data_len;
+
        msg->sock = q->sock;
 
-       data_buf = msg->buf;
+       data_buf = (uint8_t *)(msg + 1);
+
+       msg->iov = (struct iovec) {
+               .iov_base = (void *)data_buf,
+               .iov_len = data_len,
+       };
+
        for (i=0; i<iovlen; i++) {
                memcpy(data_buf, iov[i].iov_base, iov[i].iov_len);
                data_buf += iov[i].iov_len;
@@ -547,12 +553,8 @@ fail:
 static void unix_dgram_send_job(void *private_data)
 {
        struct unix_dgram_msg *dmsg = private_data;
-       struct iovec iov = {
-               .iov_base = (void *)dmsg->buf,
-               .iov_len = dmsg->buflen,
-       };
        struct msghdr msg = {
-               .msg_iov = &iov,
+               .msg_iov = &dmsg->iov,
                .msg_iovlen = 1,
        };
 #ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL