Move lease fd send/receive to dlm-protocol

Collect all protocol related functionality in the same
place instead of spreading it around across different
modules.

Bug-AGL: SPEC-3862

Signed-off-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>
Change-Id: I169a200401e4feaa289d53240a7f5467d6a88bd3

5 files changed, 110 insertions, 116 deletions

diff --git a/common/dlm-protocol.c b/common/dlm-protocol.c
index 4fc87b2..79aa86f 100644
--- a/common/dlm-protocol.c
+++ b/common/dlm-protocol.c
@@ -64,3 +64,86 @@ bool send_dlm_client_request(int socket, struct dlm_client_request *request)
 	}
 	return true;
 }
+
+int receive_lease_fd(int socket)
+{
+	int lease_fd = -1;
+	char ctrl_buf[CMSG_SPACE(sizeof(lease_fd))];
+
+	char data;
+	struct iovec iov = {.iov_base = &data, .iov_len = sizeof(data)};
+	struct msghdr msg = {
+	    .msg_iov = &iov,
+	    .msg_iovlen = 1,
+	    .msg_control = ctrl_buf,
+	    .msg_controllen = sizeof(ctrl_buf),
+	};
+
+	ssize_t len;
+	while ((len = recvmsg(socket, &msg, 0)) <= 0) {
+		if (len == 0) {
+			errno = EACCES;
+			goto err;
+		}
+
+		if (errno != EINTR)
+			goto err;
+	}
+
+	struct cmsghdr *cmsg;
+	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
+	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+		if (cmsg->cmsg_level == SOL_SOCKET &&
+		    cmsg->cmsg_type == SCM_RIGHTS) {
+			int nfds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
+			int *fds = (int *)CMSG_DATA(cmsg);
+
+			if (nfds == 1) {
+				lease_fd = fds[0];
+				break;
+			}
+
+			/* Close any unexpected fds so we don't leak them. */
+			for (int i = 0; i < nfds; i++)
+				close(fds[i]);
+			break;
+		}
+	}
+
+	if (lease_fd < 0) {
+		errno = EPROTO;
+		goto err;
+	}
+
+err:
+	return lease_fd;
+}
+
+bool send_lease_fd(int socket, int lease)
+{
+	char data;
+	struct iovec iov = {
+	    .iov_base = &data,
+	    .iov_len = sizeof(data),
+	};
+
+	char ctrl_buf[CMSG_SPACE(sizeof(lease))] = {0};
+
+	struct msghdr msg = {
+	    .msg_iov = &iov,
+	    .msg_iovlen = 1,
+	    .msg_controllen = sizeof(ctrl_buf),
+	    .msg_control = ctrl_buf,
+	};
+
+	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_SOCKET;
+	cmsg->cmsg_type = SCM_RIGHTS;
+	cmsg->cmsg_len = CMSG_LEN(sizeof(lease));
+	*((int *)CMSG_DATA(cmsg)) = lease;
+
+	if (sendmsg(socket, &msg, 0) < 0)
+		return false;
+
+	return true;
+}
diff --git a/common/dlm-protocol.h b/common/dlm-protocol.h
index 44785e5..c7e1327 100644
--- a/common/dlm-protocol.h
+++ b/common/dlm-protocol.h
@@ -29,4 +29,6 @@ struct dlm_client_request {
 
 bool receive_dlm_client_request(int socket, struct dlm_client_request *request);
 bool send_dlm_client_request(int socket, struct dlm_client_request *request);
+int receive_lease_fd(int socket);
+bool send_lease_fd(int socket, int lease);
 #endif
diff --git a/drm-lease-manager/lease-server.c b/drm-lease-manager/lease-server.c
index ac4dd01..c81d363 100644
--- a/drm-lease-manager/lease-server.c
+++ b/drm-lease-manager/lease-server.c
@@ -346,39 +346,21 @@ bool ls_send_fd(struct ls *ls, struct ls_client *client, int fd)
 	assert(ls);
 	assert(client);
 
+	struct ls_server *serv = client->serv;
+
 	if (fd < 0)
 		return false;
 
-	char data[1];
-	struct iovec iov = {
-	    .iov_base = data,
-	    .iov_len = sizeof(data),
-	};
-
-	char ctrl_buf[CMSG_SPACE(sizeof(int))] = {0};
-
-	struct msghdr msg = {
-	    .msg_iov = &iov,
-	    .msg_iovlen = 1,
-	    .msg_controllen = sizeof(ctrl_buf),
-	    .msg_control = ctrl_buf,
-	};
-
-	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
-	cmsg->cmsg_level = SOL_SOCKET;
-	cmsg->cmsg_type = SCM_RIGHTS;
-	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
-	*((int *)CMSG_DATA(cmsg)) = fd;
-
-	struct ls_server *serv = client->serv;
-
-	if (sendmsg(client->socket.fd, &msg, 0) < 0) {
+	if (!send_lease_fd(client->socket.fd, fd)) {
 		DEBUG_LOG("sendmsg failed on %s: %s\n", serv->address.sun_path,
 			  strerror(errno));
 		return false;
 	}
 
-	INFO_LOG("Lease request granted on %s\n", serv->address.sun_path);
+	if (fd > 0)
+		INFO_LOG("Lease request granted on %s\n",
+			 serv->address.sun_path);
+
 	return true;
 }
 
diff --git a/drm-lease-manager/test/test-socket-client.c b/drm-lease-manager/test/test-socket-client.c
index 9d191ff..fa26500 100644
--- a/drm-lease-manager/test/test-socket-client.c
+++ b/drm-lease-manager/test/test-socket-client.c
@@ -66,40 +66,6 @@ static void client_gst_socket_status(int socket_fd, struct test_config *config)
 	return;
 }
 
-static int receive_fd_from_socket(int sockfd)
-{
-	union {
-		struct cmsghdr align;
-		char buf[CMSG_SPACE(sizeof(int))];
-	} u;
-
-	char data;
-	struct iovec iov = {.iov_base = &data, .iov_len = sizeof(data)};
-	struct msghdr msg = {
-	    .msg_iov = &iov,
-	    .msg_iovlen = 1,
-	    .msg_control = u.buf,
-	    .msg_controllen = sizeof(u.buf),
-	};
-
-	if (recvmsg(sockfd, &msg, 0) < 0)
-		return -1;
-
-	int recv_fd = -1;
-	for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
-	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-		ck_assert_int_eq(cmsg->cmsg_level, SOL_SOCKET);
-
-		if (cmsg->cmsg_type != SCM_RIGHTS)
-			continue;
-
-		int nfds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
-		ck_assert_int_eq(nfds, 1);
-		recv_fd = *(int *)CMSG_DATA(cmsg);
-	}
-	return recv_fd;
-}
-
 static void *test_client_thread(void *arg)
 {
 	struct client_state *cstate = arg;
@@ -132,7 +98,7 @@ static void *test_client_thread(void *arg)
 	client_gst_socket_status(client, config);
 
 	if (config->has_data) {
-		config->received_fd = receive_fd_from_socket(client);
+		config->received_fd = receive_lease_fd(client);
 	}
 
 	cstate->socket_fd = client;
diff --git a/libdlmclient/dlmclient.c b/libdlmclient/dlmclient.c
index 03c08a8..dbe2609 100644
--- a/libdlmclient/dlmclient.c
+++ b/libdlmclient/dlmclient.c
@@ -82,66 +82,27 @@ static bool lease_send_request(struct dlm_lease *lease, enum dlm_opcode opcode)
 
 static bool lease_recv_fd(struct dlm_lease *lease)
 {
-	char ctrl_buf[CMSG_SPACE(sizeof(int))] = {0};
-	char data[1] = {0};
-
-	struct iovec iov[1];
-	iov[0].iov_base = data;
-	iov[0].iov_len = sizeof(data);
-
-	struct msghdr msg = {
-	    .msg_control = ctrl_buf,
-	    .msg_controllen = CMSG_SPACE(sizeof(int)),
-	    .msg_iov = iov,
-	    .msg_iovlen = 1,
-	};
+	lease->lease_fd = receive_lease_fd(lease->dlm_server_sock);
 
-	int ret;
-	while ((ret = recvmsg(lease->dlm_server_sock, &msg, 0)) <= 0) {
-		if (ret == 0) {
-			errno = EACCES;
-			DEBUG_LOG("Request rejected by DRM lease manager\n");
-			// TODO: Report why the request was rejected.
-			return false;
-		}
-		if (errno != EINTR) {
-			DEBUG_LOG("Socket data receive error: %s\n",
-				  strerror(errno));
-			return false;
-		}
-	}
+	if (lease->lease_fd < 0)
+		goto err;
 
-	lease->lease_fd = -1;
-	struct cmsghdr *cmsg;
-	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
-	     cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-		if (cmsg->cmsg_level == SOL_SOCKET &&
-		    cmsg->cmsg_type == SCM_RIGHTS) {
-			int nfds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
-			int *fds = (int *)CMSG_DATA(cmsg);
-
-			if (nfds == 1) {
-				lease->lease_fd = fds[0];
-				break;
-			}
-
-			DEBUG_LOG(
-			    "Expected 1 fd from lease manager. Received %d\n",
-			    nfds);
-			/* Close any unexpected fds so we don't leak them. */
-			for (int i = 0; i < nfds; i++)
-				close(fds[i]);
-			break;
-		}
-	}
+	return true;
 
-	if (lease->lease_fd < 0) {
-		DEBUG_LOG("Expected data not received from lease manager\n");
-		errno = EPROTO;
-		return false;
+err:
+	switch (errno) {
+	case EACCES:
+		DEBUG_LOG("Lease request rejected by DRM lease manager\n");
+		break;
+	case EPROTO:
+		DEBUG_LOG("Unexpected data received from lease manager\n");
+		break;
+	default:
+		DEBUG_LOG("Lease manager receive data error: %s\n",
+			  strerror(errno));
+		break;
 	}
-
-	return true;
+	return false;
 }
 
 struct dlm_lease *dlm_get_lease(const char *name)