int chitcpd_send_and_recv_msg(int sockfd, const ChitcpdMsg *req, ChitcpdMsg **resp)
{
int r;
if ((r = chitcpd_send_msg(sockfd, req)) < 0)
return r;
if ((r = chitcpd_recv_msg(sockfd, resp)) < 0)
return r;
return CHITCP_OK;
}
/*
* chitcpd_server_thread_func - Server thread function
*
* This function will spawn a handler thread (see handler.c) for each
* new connection on the UNIX socket.
*
* args: arguments (a serverinfo_t variable in server_threads_args_t)
*
* Returns: Nothing.
*
*/
void* chitcpd_server_thread_func(void *args)
{
socklen_t sunSize;
handler_thread_t *handler_thread;
server_thread_args_t *sta;
serverinfo_t *si;
handler_thread_args_t *ha;
list_t handler_thread_list;
int rc;
ChitcpdMsg *req;
ChitcpdInitArgs *init_args;
ChitcpdConnectionType conntype;
ChitcpdMsg resp_outer = CHITCPD_MSG__INIT;
ChitcpdResp resp_inner = CHITCPD_RESP__INIT;
resp_outer.code = CHITCPD_MSG_CODE__RESP;
resp_outer.resp = &resp_inner;
/* For naming the handler threads we create (for debugging/logging) */
int next_thread_id = 0;
pthread_setname_np(pthread_self(), "unix_server");
/* Unpack arguments */
sta = (server_thread_args_t *) args;
si = sta->si;
list_init(&handler_thread_list);
struct sockaddr_un client_addr;
/* Accept connections on the UNIX socket */
for(;;)
{
socket_t client_socket;
/* Accept a connection */
sunSize = sizeof(client_addr);
if ((client_socket = accept(si->server_socket, (struct sockaddr *)&client_addr, &sunSize)) == -1)
{
/* If accept() returns in the CHITCPD_STATE_STOPPING, we don't
* care what the error is. We just break out of the loop and
* initiate an orderly shutdown. */
if(si->state == CHITCPD_STATE_STOPPING)
break;
/* If this particular connection fails, no need to kill the entire thread. */
perror("Could not accept() connection on UNIX socket");
continue;
}
/* We receive a single message, which has to be an INIT message */
rc = chitcpd_recv_msg(client_socket, &req);
if (rc < 0)
{
if(si->state == CHITCPD_STATE_STOPPING)
break;
else
{
chilog(ERROR, "Error when receiving lead message through UNIX socket");
shutdown(client_socket, SHUT_RDWR);
continue;
}
}
if(req->code != CHITCPD_MSG_CODE__INIT)
{
chilog(ERROR, "Expected INIT message, instead got message code %i", req->code);
chitcpd_msg__free_unpacked(req, NULL);
shutdown(client_socket, SHUT_RDWR);
continue;
}
/* Unpack INIT request */
assert(req->init_args != NULL);
init_args = req->init_args;
conntype = init_args->connection_type;
/* There are two types of connections: command connections and debug
* connections.
*
* When a command connection is created, a new thread is created to
* handle the incoming chisocket commands on that connection (socket,
* send, recv, etc.)
*
* When a debug connection is created, no additional thread is necessary.
* The connection on the UNIX socket is simply "handed off" to a
* debug monitor that will be associated with a chiTCP socket.
* That UNIX socket is then used to send back debug messages.
*/
if (conntype == CHITCPD_CONNECTION_TYPE__COMMAND_CONNECTION)
{
/* Create arguments for handler thread */
ha = malloc(sizeof(handler_thread_args_t));
ha->si = si;
handler_thread = malloc(sizeof(handler_thread_t));
handler_thread->handler_socket = client_socket;
pthread_mutex_init(&handler_thread->handler_lock, NULL);
/* Create handler thread to handle this connection */
ha->client_socket = handler_thread->handler_socket;
ha->handler_lock = &handler_thread->handler_lock;
snprintf(ha->thread_name, 16, "socket-layer-%d", next_thread_id++);
if (pthread_create(&handler_thread->thread, NULL, chitcpd_handler_dispatch, ha) != 0)
{
perror("Could not create a worker thread");
resp_outer.resp->ret = CHITCP_ETHREAD;
resp_outer.resp->error_code = 0;
rc = chitcpd_send_msg(client_socket, &resp_outer);
free(ha);
close(ha->client_socket);
close(si->server_socket);
// TODO: Perform an orderly shutdown instead of exiting
pthread_exit(NULL);
}
resp_outer.resp->ret = CHITCP_OK;
resp_outer.resp->error_code = 0;
rc = chitcpd_send_msg(client_socket, &resp_outer);
list_append(&handler_thread_list, handler_thread);
}
else if(conntype == CHITCPD_CONNECTION_TYPE__DEBUG_CONNECTION)
{
int debug_sockfd, debug_event_flags;
ChitcpdDebugArgs *debug_args;
/* Unpack debug parameter */
assert(init_args->debug != NULL);
debug_args = init_args->debug;
debug_sockfd = debug_args->sockfd;
debug_event_flags = debug_args->event_flags;
rc = chitcpd_init_debug_connection(si, debug_sockfd, debug_event_flags, client_socket);
if(rc == CHITCP_OK)
{
resp_outer.resp->ret = CHITCP_OK;
resp_outer.resp->error_code = 0;
rc = chitcpd_send_msg(client_socket, &resp_outer);
}
else
{
chilog(ERROR, "Error when creating debug connection for socket %i", debug_sockfd);
resp_outer.resp->ret = CHITCP_EINIT;
resp_outer.resp->error_code = rc;
rc = chitcpd_send_msg(client_socket, &resp_outer);
shutdown(client_socket, SHUT_RDWR);
}
}
else
{
chilog(ERROR, "Received INIT message with unknown connection type %i", conntype);
resp_outer.resp->ret = CHITCP_EINVAL;
resp_outer.resp->error_code = 0;
rc = chitcpd_send_msg(client_socket, &resp_outer);
shutdown(client_socket, SHUT_RDWR);
}
chitcpd_msg__free_unpacked(req, NULL);
}
while(!list_empty(&handler_thread_list))
{
/* For each handler thread we spawned, we close its socket, which
* will force the thread to exit (and we then join it).
*
* Note that closing a handler thread will also free up all chiTCP
* sockets created through that thread, and will also terminate
* all associated TCP threads.
*
* TODO: We should simply detach those threads, since they can exit
* before an orderly shutdown and would be left lingering until
* we call join here. */
handler_thread_t *ht = list_fetch(&handler_thread_list);
/* We don't want to shutdown the handler's socket if an operation is
* in progress. The handler thread may have read a command, but
* not sent a response back yet */
pthread_mutex_lock(&ht->handler_lock);
shutdown(ht->handler_socket, SHUT_RDWR);
pthread_mutex_unlock(&ht->handler_lock);
pthread_join(ht->thread, NULL);
pthread_mutex_destroy(&ht->handler_lock);
free(ht);
}
list_destroy(&handler_thread_list);
chilog(DEBUG, "Server thread is exiting.");
pthread_exit(NULL);
}
/*
* chitcpd_handler_dispatch - Handler thread function
*
* Handles a connection on chitcpd's UNIX socket, and dispatches
* incoming requests to the appropriate function, using the
* dispatch table defined above.
*
* args: arguments (in handler_thread_args_t)
*
* Returns: Nothing.
*
*/
void* chitcpd_handler_dispatch(void *args)
{
handler_thread_args_t *ha = (handler_thread_args_t *) args;
serverinfo_t *si = ha->si;
socket_t client_socket = ha->client_socket;
pthread_mutex_t *handler_lock = ha->handler_lock;
pthread_setname_np(pthread_self(), ha->thread_name);
ChitcpdMsg *req;
ChitcpdMsg resp_outer = CHITCPD_MSG__INIT;
ChitcpdResp resp_inner = CHITCPD_RESP__INIT;
bool_t done = FALSE; /* Should we keep looping? */
int rc;
resp_outer.code = CHITCPD_MSG_CODE__RESP;
resp_outer.resp = &resp_inner;
do
{
rc = chitcpd_recv_msg(client_socket, &req);
if (rc < 0)
break;
chilog(TRACE, "Received request (code=%s)", handler_code_string(req->code));
/* We have received a request, so we grab the handler lock to
* prevent a race condition when the server is shutting down */
pthread_mutex_lock(handler_lock);
/* Call handler function using dispatch table */
rc = handlers[req->code](si, req, &resp_inner);
chitcpd_msg__free_unpacked(req, NULL);
if(rc != CHITCP_OK)
{
chilog(ERROR, "Error when handling request.");
/* We don't need to bail out just because one request failed */
}
/* Send response */
rc = chitcpd_send_msg(client_socket, &resp_outer);
if (resp_inner.has_buf)
{
/* This buffer was allocated in RECV. */
free(resp_inner.buf.data);
resp_inner.has_buf = FALSE;
}
if (resp_inner.socket_state != NULL)
{
/* This submessage was allocated in GET_SOCKET_STATE. */
free(resp_inner.socket_state);
resp_inner.socket_state = NULL;
}
if (resp_inner.socket_buffer_contents != NULL)
{
/* This submessage was allocated in GET_SOCKET_BUFFER_CONTENTS. */
if (resp_inner.socket_buffer_contents->snd.data != NULL)
free(resp_inner.socket_buffer_contents->snd.data);
if (resp_inner.socket_buffer_contents->rcv.data != NULL)
free(resp_inner.socket_buffer_contents->rcv.data);
free(resp_inner.socket_buffer_contents);
resp_inner.socket_buffer_contents = NULL;
}
/* We're done processing the request (we've run the handler and
* we've returned a response). We can release the handler lock and,
* if a shutdown is in progress, it will make sure it can proceed
* safely */
pthread_mutex_unlock(handler_lock);
if (rc < 0)
break;
}
while (!done);
/* TODO: Be more discerning about what kind of shutdown this is */
if(si->state == CHITCPD_STATE_STOPPING)
chilog(DEBUG, "chiTCP daemon is stopping. Freeing open sockets for this handler...");
else
chilog(DEBUG, "Daemon client has disconnected. Freeing open sockets for this handler...");
int freed_sockets = 0;
for(int i=0; i < si->chisocket_table_size; i++)
{
chisocketentry_t *entry = &si->chisocket_table[i];
if(!entry->available && entry->creator_thread == pthread_self())
{
chilog(DEBUG, "Freeing socket %i", i);
/* TODO: The connection should be aborted (not closed) here.
* However, we do not currently support the ABORT call or
* RST's so we simply "force close" each socket. */
if(entry->actpas_type == SOCKET_ACTIVE)
{
/* Any transition to CLOSED will force a termination of the TCP thread */
chitcpd_update_tcp_state(si, entry, CLOSED);
pthread_join(entry->socket_state.active.tcp_thread, NULL);
}
else if(entry->actpas_type == SOCKET_PASSIVE)
chitcpd_free_socket_entry(si, entry);
freed_sockets++;
/* TODO: Close the connection */
}
}
if (freed_sockets)
chilog(DEBUG, "Done freeing open sockets.");
else
chilog(DEBUG, "This handler had no sockets to free.");
chilog(DEBUG, "Handler is exiting.");
free(args);
return NULL;
}
