@@ -218,3 +218,67 @@ static int send_pipefd(int sockfd, int pipefd)
return ret;
}
+
+/*
+ * Receive a pipe file descriptor from a source process
+ * via unix socket.
+ *
+ * Return negative value if there has been an recvmsg error or
+ * no fd to be received. Return 0 if the connection closed by
+ * source. Return file descriptor on success.
+ *
+ */
+static int recv_pipefd(int sockfd)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t n;
+ int pipefd = -1;
+ char req[1];
+
+ 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);
+
+ 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;
+
+ if ( (n = recvmsg(sockfd, &msg, 0)) <= 0) {
+ fprintf(stderr, "recvmsg error: %s\n", strerror(errno));
+ return n;
+ }
+
+ /* req 0x01 means there is a file descriptor to receive */
+ if (req[0] != 0x01) {
+ return pipefd;
+ }
+
+ if ( (cmptr = CMSG_FIRSTHDR(&msg)) != NULL &&
+ cmptr->cmsg_len == CMSG_LEN(sizeof(int))) {
+ if (cmptr->cmsg_level != SOL_SOCKET) {
+ DPRINTF(stderr, "control level != SOL_SOCKET\n");
+ return pipefd;
+ } else if (cmptr->cmsg_type != SCM_RIGHTS) {
+ DPRINTF(stderr, "control type != SCM_RIGHTS\n");
+ return pipefd;
+ }
+ /* The pipe file descriptor to be received */
+ pipefd = *((int *) CMSG_DATA(cmptr));
+ DPRINTF("pipefd received successfully: %d\n", pipefd);
+ } else {
+ /* Descriptor was not passed */
+ DPRINTF(stderr, "pipefd was not passed\n");
+ }
+
+ return pipefd;
+}
This patch adds recv_pipefd() to receive the pipe file descriptor that passed by source process. Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com> --- migration-local.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 64 insertions(+), 0 deletions(-)