*/
#include "lease-server.h"
+
+#include "dlm-protocol.h"
#include "log.h"
#include "socket-path.h"
#define SOCK_LOCK_SUFFIX ".lock"
+/* ACTIVE_CLIENTS
+ * An 'active' client is one that either
+ * - owns a lease, or
+ * - is requesting ownership of a lease (which will
+ * disconnect the current owner if granted)
+ *
+ * There can only be at most one of each kind of client at the same
+ * time. Any other client connections are queued in the
+ * listen() backlog, waiting to be accept()'ed.
+ */
+#define ACTIVE_CLIENTS 2
+
struct ls_socket {
int fd;
+ bool is_server;
+ union {
+ struct ls_server *server;
+ struct ls_client *client;
+ };
+};
+
+struct ls_client {
+ struct ls_socket socket;
struct ls_server *serv;
+ bool is_connected;
};
struct ls_server {
int server_socket_lock;
struct ls_socket listen;
- struct ls_socket client;
-
- bool is_client_connected;
+ struct ls_client clients[ACTIVE_CLIENTS];
};
struct ls {
int nservers;
};
-static bool client_connect(struct ls *ls, struct ls_server *serv)
+static void client_connect(struct ls *ls, struct ls_server *serv)
{
int cfd = accept(serv->listen.fd, NULL, NULL);
if (cfd < 0) {
DEBUG_LOG("accept failed on %s: %s\n", serv->address.sun_path,
strerror(errno));
- return false;
+ return;
}
- if (serv->is_client_connected) {
- WARN_LOG("Client already connected on %s\n",
- serv->address.sun_path);
+ struct ls_client *client = NULL;
+
+ for (int i = 0; i < ACTIVE_CLIENTS; i++) {
+ if (!serv->clients[i].is_connected) {
+ client = &serv->clients[i];
+ break;
+ }
+ }
+ if (!client) {
close(cfd);
- return false;
+ return;
}
- serv->client.fd = cfd;
- serv->client.serv = serv;
+ client->socket.fd = cfd;
struct epoll_event ev = {
- .events = POLLHUP,
- .data.ptr = &serv->client,
+ .events = POLLIN,
+ .data.ptr = &client->socket,
};
if (epoll_ctl(ls->epoll_fd, EPOLL_CTL_ADD, cfd, &ev)) {
DEBUG_LOG("epoll_ctl add failed: %s\n", strerror(errno));
close(cfd);
- return false;
+ return;
}
- serv->is_client_connected = true;
- return true;
+ client->is_connected = true;
+}
+
+static int parse_client_request(struct ls_socket *client)
+{
+ int ret = -1;
+ struct dlm_client_request hdr;
+ if (!receive_dlm_client_request(client->fd, &hdr))
+ return ret;
+
+ switch (hdr.opcode) {
+ case DLM_GET_LEASE:
+ ret = LS_REQ_GET_LEASE;
+ break;
+ case DLM_RELEASE_LEASE:
+ ret = LS_REQ_RELEASE_LEASE;
+ break;
+ default:
+ ERROR_LOG("Unexpected client request received\n");
+ break;
+ };
+
+ return ret;
}
static int create_socket_lock(struct sockaddr_un *addr)
address->sun_family = AF_UNIX;
- int server_socket = socket(PF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0);
+ int server_socket = socket(PF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
if (server_socket < 0) {
DEBUG_LOG("Socket creation failed: %s\n", strerror(errno));
return false;
return false;
}
- serv->is_client_connected = false;
+ for (int i = 0; i < ACTIVE_CLIENTS; i++) {
+ struct ls_client *client = &serv->clients[i];
+ client->serv = serv;
+ client->socket.client = client;
+ }
+
serv->lease_handle = lease_handle;
serv->server_socket_lock = socket_lock;
+
serv->listen.fd = server_socket;
- serv->listen.serv = serv;
+ serv->listen.server = serv;
+ serv->listen.is_server = true;
struct epoll_event ev = {
.events = POLLIN,
epoll_ctl(ls->epoll_fd, EPOLL_CTL_DEL, serv->listen.fd, NULL);
close(serv->listen.fd);
- ls_disconnect_client(ls, serv);
+
+ for (int i = 0; i < ACTIVE_CLIENTS; i++)
+ ls_disconnect_client(ls, &serv->clients[i]);
+
close(serv->server_socket_lock);
}
struct ls_socket *sock = ev.data.ptr;
assert(sock);
- struct ls_server *server = sock->serv;
- req->lease_handle = server->lease_handle;
- req->server = server;
+ if (sock->is_server) {
+ if (ev.events & POLLIN)
+ client_connect(ls, sock->server);
+ continue;
+ }
- if (sock == &server->listen) {
- if (!(ev.events & POLLIN))
- continue;
- if (client_connect(ls, server))
- request = LS_REQ_GET_LEASE;
- } else if (sock == &server->client) {
- if (!(ev.events & POLLHUP))
- continue;
+ if (ev.events & POLLIN)
+ request = parse_client_request(sock);
+
+ if (request < 0 && (ev.events & POLLHUP))
request = LS_REQ_RELEASE_LEASE;
- } else {
- ERROR_LOG("Internal error: Invalid socket context\n");
- return false;
- }
+
+ struct ls_client *client = sock->client;
+ struct ls_server *server = client->serv;
+
+ req->lease_handle = server->lease_handle;
+ req->client = client;
+ req->type = request;
}
- req->type = request;
return true;
}
-bool ls_send_fd(struct ls *ls, struct ls_server *serv, int fd)
+bool ls_send_fd(struct ls *ls, struct ls_client *client, int fd)
{
assert(ls);
- assert(serv);
+ 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;
-
- if (sendmsg(serv->client.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;
}
-void ls_disconnect_client(struct ls *ls, struct ls_server *serv)
+void ls_disconnect_client(struct ls *ls, struct ls_client *client)
{
assert(ls);
- assert(serv);
- if (!serv->is_client_connected)
+ assert(client);
+
+ if (!client->is_connected)
return;
- epoll_ctl(ls->epoll_fd, EPOLL_CTL_DEL, serv->client.fd, NULL);
- close(serv->client.fd);
- serv->is_client_connected = false;
+ epoll_ctl(ls->epoll_fd, EPOLL_CTL_DEL, client->socket.fd, NULL);
+ close(client->socket.fd);
+ client->is_connected = false;
}
Code Review / src / drm-lease-manager.git / blobdiff