From: Volker Lendecke <vl@samba.org>
Date: Wed, 31 Dec 2014 13:18:59 +0000 (+0100)
Subject: lib: Add msghdr_prep_recv_fds
X-Git-Tag: ldb-1.1.20~138
X-Git-Url: http://git.samba.org/?a=commitdiff_plain;h=37af87e75e6efb7393f6e7572aaa4bef8f38920f;p=samba.git

lib: Add msghdr_prep_recv_fds

This will prepare a msghdr for receiving fd's. Same pattern as before: First
get the buffer size, then fill in msghdr.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
---

diff --git a/source3/lib/msghdr.c b/source3/lib/msghdr.c
index 3449579b438..9ed14449cfe 100644
--- a/source3/lib/msghdr.c
+++ b/source3/lib/msghdr.c
@@ -126,6 +126,26 @@ struct msghdr *msghdr_buf_msghdr(struct msghdr_buf *msg)
 	return &msg->msg;
 }
 
+size_t msghdr_prep_recv_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
+			    size_t num_fds)
+{
+	size_t ret = CMSG_SPACE(sizeof(int) * num_fds);
+
+	if (bufsize < ret) {
+		return ret;
+	}
+	if (msg != NULL) {
+		if (num_fds != 0) {
+			msg->msg_control = buf;
+			msg->msg_controllen = ret;
+		} else {
+			msg->msg_control = NULL;
+			msg->msg_controllen = 0;
+		}
+	}
+	return ret;
+}
+
 size_t msghdr_extract_fds(struct msghdr *msg, int *fds, size_t fds_size)
 {
 	struct cmsghdr *cmsg;
diff --git a/source3/lib/msghdr.h b/source3/lib/msghdr.h
index 88829238a2b..c1676d2e4de 100644
--- a/source3/lib/msghdr.h
+++ b/source3/lib/msghdr.h
@@ -35,6 +35,8 @@ ssize_t msghdr_copy(struct msghdr_buf *msg, size_t msgsize,
 		    const int *fds, size_t num_fds);
 struct msghdr *msghdr_buf_msghdr(struct msghdr_buf *msg);
 
+size_t msghdr_prep_recv_fds(struct msghdr *msg, uint8_t *buf, size_t bufsize,
+			    size_t num_fds);
 size_t msghdr_extract_fds(struct msghdr *msg, int *fds, size_t num_fds);
 
 #endif