--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+
+ Echo server service example
+
+ Copyright (C) 2010 Kai Blin <kai@samba.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "echo_server/echo_server.h"
+/* Get at the config file settings */
+#include "param/param.h"
+/* This defines task_server_terminate */
+#include "smbd/process_model.h"
+/* We get load_interfaces from here */
+#include "socket/netif.h"
+/* NTSTATUS-related stuff */
+#include "libcli/util/ntstatus.h"
+/* tsocket-related functions */
+#include "lib/tsocket/tsocket.h"
+
+/* Structure to hold an echo server socket */
+struct echo_socket {
+ /* This can come handy for the task struct in there */
+ struct echo_server *echo;
+ struct tsocket_address *local_address;
+};
+
+/* Structure to hold udp socket */
+struct echo_udp_socket {
+ struct echo_socket *echo_socket;
+ struct tdgram_context *dgram;
+ struct tevent_queue *send_queue;
+};
+
+/*
+ * Main processing function.
+ *
+ * This is the start of the package processing.
+ * In the echo server it doesn't do much, but for more complicated servers,
+ * your code goes here (or at least is called from here.
+ */
+static NTSTATUS echo_process(struct echo_server *echo,
+ TALLOC_CTX *mem_ctx,
+ DATA_BLOB *in,
+ DATA_BLOB *out)
+{
+ uint8_t *buf = talloc_memdup(mem_ctx, in->data, in->length);
+ NT_STATUS_HAVE_NO_MEMORY(buf);
+
+ out->data = buf;
+ out->length = in->length;
+
+ return NT_STATUS_OK;
+}
+
+/* Structure keeping track of a single UDP echo server call */
+struct echo_udp_call {
+ /* The UDP packet came from here, our reply goes there as well */
+ struct tsocket_address *src;
+ DATA_BLOB in;
+ DATA_BLOB out;
+};
+
+/** Prototype of the send callback */
+static void echo_udp_call_sendto_done(struct tevent_req *subreq);
+
+/* Callback to receive UDP packets */
+static void echo_udp_call_loop(struct tevent_req *subreq)
+{
+ /*
+ * Our socket structure is the callback data. Get it in a
+ * type-safe way
+ */
+ struct echo_udp_socket *sock = tevent_req_callback_data(subreq,
+ struct echo_udp_socket);
+ struct echo_udp_call *call;
+ uint8_t *buf;
+ ssize_t len;
+ NTSTATUS status;
+ int sys_errno;
+
+ call = talloc(sock, struct echo_udp_call);
+ if (call == NULL) {
+ goto done;
+ }
+
+ len = tdgram_recvfrom_recv(subreq, &sys_errno, call, &buf, &call->src);
+ TALLOC_FREE(subreq);
+ if (len == -1) {
+ TALLOC_FREE(call);
+ goto done;
+ }
+
+ call->in.data = buf;
+ call->in.length = len;
+
+ DEBUG(10, ("Received echo UDP packet of %lu bytes from %s\n",
+ (long)len, tsocket_address_string(call->src, call)));
+
+ /* Handle the data coming in and compute the reply */
+ status = echo_process(sock->echo_socket->echo, call,
+ &call->in, &call->out);
+ if (!NT_STATUS_IS_OK(status)) {
+ TALLOC_FREE(call);
+ DEBUG(0, ("echo_process returned %s\n",
+ nt_errstr(status)));
+ goto done;
+ }
+
+ /* I said the task struct would come in handy. */
+ subreq = tdgram_sendto_queue_send(call,
+ sock->echo_socket->echo->task->event_ctx,
+ sock->dgram,
+ sock->send_queue,
+ call->out.data,
+ call->out.length,
+ call->src);
+ if (subreq == NULL) {
+ TALLOC_FREE(call);
+ goto done;
+ }
+
+ tevent_req_set_callback(subreq, echo_udp_call_sendto_done, call);
+
+done:
+ /* Now loop for the next incoming UDP packet, the async way */
+ subreq = tdgram_recvfrom_send(sock,
+ sock->echo_socket->echo->task->event_ctx,
+ sock->dgram);
+ if (subreq == NULL) {
+ task_server_terminate(sock->echo_socket->echo->task,
+ "no memory for tdgram_recvfrom_send",
+ true);
+ return;
+ }
+ tevent_req_set_callback(subreq, echo_udp_call_loop, sock);
+}
+
+/* Callback to send UDP replies */
+static void echo_udp_call_sendto_done(struct tevent_req *subreq)
+{
+ struct echo_udp_call *call = tevent_req_callback_data(subreq,
+ struct echo_udp_call);
+ ssize_t ret;
+ int sys_errno;
+
+ ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
+
+ /*
+ * We don't actually care about the error, just get on with our life.
+ * We already set a new echo_udp_call_loop callback already, so we're
+ * almost done, just some memory to free.
+ */
+ TALLOC_FREE(call);
+}
+
+/* Start listening on a given address */
+static NTSTATUS echo_add_socket(struct echo_server *echo,
+ const struct model_ops *ops,
+ const char *name,
+ const char *address,
+ uint16_t port)
+{
+ struct echo_socket *echo_socket;
+ struct echo_udp_socket *echo_udp_socket;
+ struct tevent_req *udpsubreq;
+ NTSTATUS status;
+ int ret;
+
+ echo_socket = talloc(echo, struct echo_socket);
+ NT_STATUS_HAVE_NO_MEMORY(echo_socket);
+
+ echo_socket->echo = echo;
+
+ /*
+ * Initialize the tsocket_address.
+ * The nifty part is the "ip" string. This tells tsocket to autodetect
+ * ipv4 or ipv6 based on the IP address string passed.
+ */
+ ret = tsocket_address_inet_from_strings(echo_socket, "ip",
+ address, port,
+ &echo_socket->local_address);
+ if (ret != 0) {
+ status = map_nt_error_from_unix(errno);
+ return status;
+ }
+
+ /* Now set up the udp socket */
+ echo_udp_socket = talloc(echo_socket, struct echo_udp_socket);
+ NT_STATUS_HAVE_NO_MEMORY(echo_udp_socket);
+
+ echo_udp_socket->echo_socket = echo_socket;
+
+ ret = tdgram_inet_udp_socket(echo_socket->local_address,
+ NULL,
+ echo_udp_socket,
+ &echo_udp_socket->dgram);
+ if (ret != 0) {
+ status = map_nt_error_from_unix(errno);
+ DEBUG(0, ("Failed to bind to %s:%u UDP - %s\n",
+ address, port, nt_errstr(status)));
+ return status;
+ }
+
+ /*
+ * We set up a send queue so we can have multiple UDP packets in flight
+ */
+ echo_udp_socket->send_queue = tevent_queue_create(echo_udp_socket,
+ "echo_udp_send_queue");
+ NT_STATUS_HAVE_NO_MEMORY(echo_udp_socket->send_queue);
+
+ /*
+ * To handle the UDP requests, set up a new tevent request as a
+ * subrequest of the current one.
+ */
+ udpsubreq = tdgram_recvfrom_send(echo_udp_socket,
+ echo->task->event_ctx,
+ echo_udp_socket->dgram);
+ NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
+ tevent_req_set_callback(udpsubreq, echo_udp_call_loop, echo_udp_socket);
+
+ return NT_STATUS_OK;
+}
+
+/* Set up the listening sockets */
+static NTSTATUS echo_startup_interfaces(struct echo_server *echo,
+ struct loadparm_context *lp_ctx,
+ struct interface *ifaces)
+{
+ const struct model_ops *model_ops;
+ int num_interfaces;
+ TALLOC_CTX *tmp_ctx = talloc_new(echo);
+ NTSTATUS status;
+ int i;
+
+ /*
+ * Samba allows subtask to set their own process model.
+ * Available models currently are:
+ * - onefork (forks exactly one child process)
+ * - prefork (keep a couple of child processes around)
+ * - single (only run a single process)
+ * - standard (fork one subprocess per incoming connection)
+ * - thread (use threads instead of forks)
+ *
+ * For the echo server, the "single" process model works fine,
+ * you probably don't want to use the thread model unless you really
+ * know what you're doing.
+ */
+
+ model_ops = process_model_startup("single");
+ if (model_ops == NULL) {
+ DEBUG(0, ("Can't find 'single' proces model_ops\n"));
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ num_interfaces = iface_count(ifaces);
+
+ for(i=0; i<num_interfaces; i++) {
+ const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
+
+ status = echo_add_socket(echo, model_ops, "echo", address, ECHO_SERVICE_PORT);
+ NT_STATUS_NOT_OK_RETURN(status);
+ }
+
+ TALLOC_FREE(tmp_ctx);
+ return NT_STATUS_OK;
+}
+
+
+/* Do the basic task initialization, check if the task should run */
+
+static void echo_task_init(struct task_server *task)
+{
+ struct interface *ifaces;
+ struct echo_server *echo;
+ NTSTATUS status;
+
+ /*
+ * For the purpose of the example, let's only start the server in DC
+ * and standalone modes, and not as a member server.
+ */
+ switch(lpcfg_server_role(task->lp_ctx)) {
+ case ROLE_STANDALONE:
+ /* Yes, we want to run the echo server */
+ break;
+ case ROLE_DOMAIN_MEMBER:
+ task_server_terminate(task, "echo: Not starting echo server " \
+ "for domain members", false);
+ return;
+ case ROLE_DOMAIN_CONTROLLER:
+ /* Yes, we want to run the echo server */
+ break;
+ }
+
+ load_interfaces(task, lpcfg_interfaces(task->lp_ctx), &ifaces);
+
+ if (iface_count(ifaces) == 0) {
+ task_server_terminate(task,
+ "echo: No network interfaces configured",
+ false);
+ return;
+ }
+
+ task_server_set_title(task, "task[echo]");
+
+ echo = talloc_zero(task, struct echo_server);
+ if (echo == NULL) {
+ task_server_terminate(task, "echo: Out of memory", true);
+ return;
+ }
+
+ echo->task = task;
+
+ status = echo_startup_interfaces(echo, task->lp_ctx, ifaces);
+ if (!NT_STATUS_IS_OK(status)) {
+ task_server_terminate(task, "echo: Failed to set up interfaces",
+ true);
+ return;
+ }
+}
+
+/*
+ * Register this server service with the main samba process.
+ *
+ * This is the function you need to put into the wscript_build file as
+ * init_function. All the real work happens in "echo_task_init" above.
+ */
+NTSTATUS server_service_echo_init(void)
+{
+ return register_server_service("echo", echo_task_init);
+}
git.samba.org / kai / samba.git / commitdiff