1 files changed, 282 insertions, 0 deletions

diff --git a/source4/lib/socket/connect_multi.c b/source4/lib/socket/connect_multi.c
new file mode 100644
index 0000000000..2f736a4b05
--- /dev/null
+++ b/source4/lib/socket/connect_multi.c
@@ -0,0 +1,282 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Fire connect requests to a host and a number of ports, with a timeout
+   between the connect request. Return if the first connect comes back
+   successfully or return the last error.
+
+   Copyright (C) Volker Lendecke 2005
+   
+   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 "lib/socket/socket.h"
+#include "lib/events/events.h"
+#include "libcli/composite/composite.h"
+#include "libcli/resolve/resolve.h"
+#include "param/param.h"
+
+#define MULTI_PORT_DELAY 2000 /* microseconds */
+
+/*
+  overall state
+*/
+struct connect_multi_state {
+	const char *server_address;
+	int num_ports;
+	uint16_t *ports;
+
+	struct resolve_context *resolve_ctx;
+
+	struct socket_context *sock;
+	uint16_t result_port;
+
+	int num_connects_sent, num_connects_recv;
+};
+
+/*
+  state of an individual socket_connect_send() call
+*/
+struct connect_one_state {
+	struct composite_context *result;
+	struct socket_context *sock;
+	struct socket_address *addr;
+};
+
+static void continue_resolve_name(struct composite_context *creq);
+static void connect_multi_timer(struct event_context *ev,
+				    struct timed_event *te,
+				    struct timeval tv, void *p);
+static void connect_multi_next_socket(struct composite_context *result);
+static void continue_one(struct composite_context *creq);
+
+/*
+  setup an async socket_connect, with multiple ports
+*/
+_PUBLIC_ struct composite_context *socket_connect_multi_send(
+						    TALLOC_CTX *mem_ctx,
+						    const char *server_address,
+						    int num_server_ports,
+						    uint16_t *server_ports,
+						    struct resolve_context *resolve_ctx,
+						    struct event_context *event_ctx)
+{
+	struct composite_context *result;
+	struct connect_multi_state *multi;
+	int i;
+
+	result = talloc_zero(mem_ctx, struct composite_context);
+	if (result == NULL) return NULL;
+	result->state = COMPOSITE_STATE_IN_PROGRESS;
+	result->event_ctx = event_ctx;
+
+	multi = talloc_zero(result, struct connect_multi_state);
+	if (composite_nomem(multi, result)) goto failed;
+	result->private_data = multi;
+
+	multi->server_address = talloc_strdup(multi, server_address);
+	if (composite_nomem(multi->server_address, result)) goto failed;
+
+	multi->num_ports = num_server_ports;
+	multi->resolve_ctx = talloc_reference(multi, resolve_ctx);
+	multi->ports = talloc_array(multi, uint16_t, multi->num_ports);
+	if (composite_nomem(multi->ports, result)) goto failed;
+
+	for (i=0; i<multi->num_ports; i++) {
+		multi->ports[i] = server_ports[i];
+	}
+
+	if (!is_ipaddress(server_address)) {
+		/*  
+		    we don't want to do the name resolution separately
+		    for each port, so start it now, then only start on
+		    the real sockets once we have an IP
+		 */
+		struct nbt_name name;
+		struct composite_context *creq;
+		make_nbt_name_client(&name, server_address);
+		creq = resolve_name_send(resolve_ctx, &name, result->event_ctx);
+		if (composite_nomem(creq, result)) goto failed;
+		composite_continue(result, creq, continue_resolve_name, result);
+		return result;
+	}
+
+	/* now we've setup the state we can process the first socket */
+	connect_multi_next_socket(result);
+
+	if (!NT_STATUS_IS_OK(result->status)) {
+		goto failed;
+	}
+
+	return result;
+
+ failed:
+	composite_error(result, result->status);
+	return result;
+}
+
+/*
+  start connecting to the next socket/port in the list
+*/
+static void connect_multi_next_socket(struct composite_context *result)
+{
+	struct connect_multi_state *multi = talloc_get_type(result->private_data, 
+							    struct connect_multi_state);
+	struct connect_one_state *state;
+	struct composite_context *creq;
+	int next = multi->num_connects_sent;
+
+	if (next == multi->num_ports) {
+		/* don't do anything, just wait for the existing ones to finish */
+		return;
+	}
+
+	multi->num_connects_sent += 1;
+
+	state = talloc(multi, struct connect_one_state);
+	if (composite_nomem(state, result)) return;
+
+	state->result = result;
+	result->status = socket_create("ipv4", SOCKET_TYPE_STREAM, &state->sock, 0);
+	if (!composite_is_ok(result)) return;
+
+	/* Form up the particular address we are interested in */
+	state->addr = socket_address_from_strings(state, state->sock->backend_name, 
+						  multi->server_address, multi->ports[next]);
+	if (composite_nomem(state->addr, result)) return;
+
+	talloc_steal(state, state->sock);
+
+	creq = socket_connect_send(state->sock, NULL, 
+				   state->addr, 0, multi->resolve_ctx, 
+				   result->event_ctx);
+	if (composite_nomem(creq, result)) return;
+	talloc_steal(state, creq);
+
+	composite_continue(result, creq, continue_one, state);
+
+	/* if there are more ports to go then setup a timer to fire when we have waited
+	   for a couple of milli-seconds, when that goes off we try the next port regardless
+	   of whether this port has completed */
+	if (multi->num_ports > multi->num_connects_sent) {
+		/* note that this timer is a child of the single
+		   connect attempt state, so it will go away when this
+		   request completes */
+		event_add_timed(result->event_ctx, state,
+				timeval_current_ofs(0, MULTI_PORT_DELAY),
+				connect_multi_timer, result);
+	}
+}
+
+/*
+  a timer has gone off telling us that we should try the next port
+*/
+static void connect_multi_timer(struct event_context *ev,
+				struct timed_event *te,
+				struct timeval tv, void *p)
+{
+	struct composite_context *result = talloc_get_type(p, struct composite_context);
+	connect_multi_next_socket(result);
+}
+
+
+/*
+  recv name resolution reply then send the next connect
+*/
+static void continue_resolve_name(struct composite_context *creq)
+{
+	struct composite_context *result = talloc_get_type(creq->async.private_data, 
+							   struct composite_context);
+	struct connect_multi_state *multi = talloc_get_type(result->private_data, 
+							    struct connect_multi_state);
+	const char *addr;
+
+	result->status = resolve_name_recv(creq, multi, &addr);
+	if (!composite_is_ok(result)) return;
+
+	multi->server_address = addr;
+
+	connect_multi_next_socket(result);
+}
+
+/*
+  one of our socket_connect_send() calls hash finished. If it got a
+  connection or there are none left then we are done
+*/
+static void continue_one(struct composite_context *creq)
+{
+	struct connect_one_state *state = talloc_get_type(creq->async.private_data, 
+							  struct connect_one_state);
+	struct composite_context *result = state->result;
+	struct connect_multi_state *multi = talloc_get_type(result->private_data, 
+							    struct connect_multi_state);
+	NTSTATUS status;
+	multi->num_connects_recv++;
+
+	status = socket_connect_recv(creq);
+
+	if (NT_STATUS_IS_OK(status)) {
+		multi->sock = talloc_steal(multi, state->sock);
+		multi->result_port = state->addr->port;
+	}
+
+	talloc_free(state);
+
+	if (NT_STATUS_IS_OK(status) || 
+	    multi->num_connects_recv == multi->num_ports) {
+		result->status = status;
+		composite_done(result);
+		return;
+	}
+
+	/* try the next port */
+	connect_multi_next_socket(result);
+}
+
+/*
+  async recv routine for socket_connect_multi()
+ */
+_PUBLIC_ NTSTATUS socket_connect_multi_recv(struct composite_context *ctx,
+				   TALLOC_CTX *mem_ctx,
+				   struct socket_context **sock,
+				   uint16_t *port)
+{
+	NTSTATUS status = composite_wait(ctx);
+	if (NT_STATUS_IS_OK(status)) {
+		struct connect_multi_state *multi =
+			talloc_get_type(ctx->private_data,
+					struct connect_multi_state);
+		*sock = talloc_steal(mem_ctx, multi->sock);
+		*port = multi->result_port;
+	}
+	talloc_free(ctx);
+	return status;
+}
+
+NTSTATUS socket_connect_multi(TALLOC_CTX *mem_ctx,
+			      const char *server_address,
+			      int num_server_ports, uint16_t *server_ports,
+			      struct resolve_context *resolve_ctx,
+			      struct event_context *event_ctx,
+			      struct socket_context **result,
+			      uint16_t *result_port)
+{
+	struct composite_context *ctx =
+		socket_connect_multi_send(mem_ctx, server_address,
+					  num_server_ports, server_ports,
+					  resolve_ctx,
+					  event_ctx);
+	return socket_connect_multi_recv(ctx, mem_ctx, result, result_port);
+}