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 <li...@linux.vnet.ibm.com>
> ---
> 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.
Daniel
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