On Mon, Dec 02, 2013 at 05:19:06PM +0800, Lei Li wrote:
This patch adds send_pipefd() to pass the pipe file descriptor
to destination process.
Signed-off-by: Lei Li <address@hidden>
---
migration-local.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 46 insertions(+), 0 deletions(-)
diff --git a/migration-local.c b/migration-local.c
index 929ed60..f479530 100644
--- a/migration-local.c
+++ b/migration-local.c
@@ -167,3 +167,49 @@ fail:
g_free(s);
return NULL;
}
+
+
+/*
+ * Pass a pipe file descriptor to another process.
+ *
+ * Return negative value If pipefd < 0. Return 0 on
+ * success.
+ *
+ */
+static int send_pipefd(int sockfd, int pipefd)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret;
+ char req[1] = { 0x01 };
+
+ union {
+ struct cmsghdr cm;
+ char control[CMSG_SPACE(sizeof(int))];
+ } control_un;
+ struct cmsghdr *cmptr;
+
+ msg.msg_control = control_un.control;
+ msg.msg_controllen = sizeof(control_un.control);
+
+ cmptr = CMSG_FIRSTHDR(&msg);
+ cmptr->cmsg_len = CMSG_LEN(sizeof(int));
+ cmptr->cmsg_level = SOL_SOCKET;
+ cmptr->cmsg_type = SCM_RIGHTS;
+ *((int *) CMSG_DATA(cmptr)) = pipefd;
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+
+ iov[0].iov_base = req;
+ iov[0].iov_len = sizeof(req);
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ ret = sendmsg(sockfd, &msg, 0);
+ if (ret <= 0) {
+ DPRINTF("sendmsg error: %s\n", strerror(errno));
+ }
+
+ return ret;
+}
Just a reminder about my comments from previous posting. This is
introducing a 3rd private function for sending FDs. The existing
code should be refactored into qemu-socket.{c,h} and shared.