server.c

这是Linux环境下的蓝牙源代码

/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2004-2008  Marcel Holtmann <[e-mail]>
 *
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <net/if.h>

#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/bnep.h>
#include <bluetooth/l2cap.h>
#include <bluetooth/sdp.h>
#include <bluetooth/sdp_lib.h>

#include <netinet/in.h>

#include <glib.h>
#include <gdbus.h>

#include "../src/dbus-common.h"

#include "logging.h"
#include "error.h"
#include "textfile.h"
#include "dbus-service.h"
#include "sdpd.h"
#include "glib-helper.h"

#define NETWORK_SERVER_INTERFACE "org.bluez.network.Server"
#define SETUP_TIMEOUT		1000
#define MAX_SETUP_ATTEMPTS	3

#include "bridge.h"
#include "common.h"
#include "manager.h"

/* Pending Authorization */
struct setup_session {
	char		*address;	/* Remote Bluetooth Address */
	uint16_t	dst_role;	/* Destination role */
	uint16_t	src_role;	/* Source role */
	int		nsk;		/* L2CAP socket */
	guint		watch;		/* BNEP socket watch */
};

struct timeout {
	guint	id;		/* Timeout id */
	guint	watch;		/* BNEP socket watch */
};

/* Main server structure */
struct network_server {
	bdaddr_t	src;		/* Bluetooth Local Address */
	char		*iface;		/* Routing interface */
	char		*name;		/* Server service name */
	char		*range;		/* IP Address range */
	char		*path;		/* D-Bus path */
	gboolean	enable;		/* Enable flag */
	uint32_t	record_id;	/* Service record id */
	uint16_t	id;		/* Service class identifier */
	GSList		*clients;	/* Active connections */
};

static GIOChannel *bnep_io = NULL;
static DBusConnection *connection = NULL;
static struct setup_session *setup = NULL;
static GSList *servers = NULL;
static const char *prefix = NULL;
static gboolean security = TRUE;

gint find_server(gconstpointer a, gconstpointer b)
{
	const struct network_server *ns = a;
	const char *path = b;

	return strcmp(ns->path, path);
}

static struct setup_session *setup_session_new(gchar *address,
		uint16_t dst_role, uint16_t src_role, int nsk, guint watch)
{
	struct setup_session *setup;

	setup = g_new0(struct setup_session, 1);
	setup->address = g_strdup(address);
	setup->dst_role = dst_role;
	setup->src_role = src_role;
	setup->nsk = nsk;
	setup->watch = watch;

	return setup;
}

static void setup_session_free(struct setup_session *setup)
{
	g_source_remove(setup->watch);
	g_free(setup->address);
	g_free(setup);
}

static struct network_server *server_find(bdaddr_t *src, uint16_t role)
{
	struct network_server *ns;
	GSList *l;

	for (l = servers; l; l = l->next) {
		ns = l->data;
		if (bacmp(&ns->src, src) != 0)
			continue;
		if (ns->id == role)
			return ns;
	}

	return NULL;
}

static int store_property(bdaddr_t *src, uint16_t id,
			const char *key, const char *value)
{
	char filename[PATH_MAX + 1];
	char addr[18];

	ba2str(src, addr);
	if (id == BNEP_SVC_NAP)
		create_name(filename, PATH_MAX, STORAGEDIR, addr, "nap");
	else if (id == BNEP_SVC_GN)
		create_name(filename, PATH_MAX, STORAGEDIR, addr, "gn");
	else if (id == BNEP_SVC_PANU)
		create_name(filename, PATH_MAX, STORAGEDIR, addr, "panu");

	return textfile_put(filename, key, value);
}

static void add_lang_attr(sdp_record_t *r)
{
	sdp_lang_attr_t base_lang;
	sdp_list_t *langs = 0;

	/* UTF-8 MIBenum (http://www.iana.org/assignments/character-sets) */
	base_lang.code_ISO639 = (0x65 << 8) | 0x6e;
	base_lang.encoding = 106;
	base_lang.base_offset = SDP_PRIMARY_LANG_BASE;
	langs = sdp_list_append(0, &base_lang);
	sdp_set_lang_attr(r, langs);
	sdp_list_free(langs, 0);
}

static sdp_record_t *server_record_new(const char *name, uint16_t id)
{
	sdp_list_t *svclass, *pfseq, *apseq, *root, *aproto;
	uuid_t root_uuid, pan, l2cap, bnep;
	sdp_profile_desc_t profile[1];
	sdp_list_t *proto[2];
	sdp_data_t *v, *p;
	uint16_t psm = BNEP_PSM, version = 0x0100;
	uint16_t security_desc = (security ? 0x0001 : 0x0000);
	uint16_t net_access_type = 0xfffe;
	uint32_t max_net_access_rate = 0;
	const char *desc = "BlueZ PAN service";
	sdp_record_t *record;

	record = sdp_record_alloc();
	if (!record)
		return NULL;

	record->attrlist = NULL;
	record->pattern = NULL;

	switch (id) {
	case BNEP_SVC_NAP:
		sdp_uuid16_create(&pan, NAP_SVCLASS_ID);
		svclass = sdp_list_append(NULL, &pan);
		sdp_set_service_classes(record, svclass);

		sdp_uuid16_create(&profile[0].uuid, NAP_PROFILE_ID);
		profile[0].version = 0x0100;
		pfseq = sdp_list_append(NULL, &profile[0]);
		sdp_set_profile_descs(record, pfseq);

		sdp_set_info_attr(record, name, NULL, desc);

		sdp_attr_add_new(record, SDP_ATTR_NET_ACCESS_TYPE,
					SDP_UINT16, &net_access_type);
		sdp_attr_add_new(record, SDP_ATTR_MAX_NET_ACCESSRATE,
					SDP_UINT32, &max_net_access_rate);
		break;
	case BNEP_SVC_GN:
		sdp_uuid16_create(&pan, GN_SVCLASS_ID);
		svclass = sdp_list_append(NULL, &pan);
		sdp_set_service_classes(record, svclass);

		sdp_uuid16_create(&profile[0].uuid, GN_PROFILE_ID);
		profile[0].version = 0x0100;
		pfseq = sdp_list_append(NULL, &profile[0]);
		sdp_set_profile_descs(record, pfseq);

		sdp_set_info_attr(record, name, NULL, desc);
		break;
	case BNEP_SVC_PANU:
		sdp_uuid16_create(&pan, PANU_SVCLASS_ID);
		svclass = sdp_list_append(NULL, &pan);
		sdp_set_service_classes(record, svclass);

		sdp_uuid16_create(&profile[0].uuid, PANU_PROFILE_ID);
		profile[0].version = 0x0100;
		pfseq = sdp_list_append(NULL, &profile[0]);
		sdp_set_profile_descs(record, pfseq);

		sdp_set_info_attr(record, name, NULL, desc);
		break;
	default:
		return NULL;
	}

	sdp_uuid16_create(&root_uuid, PUBLIC_BROWSE_GROUP);
	root = sdp_list_append(NULL, &root_uuid);
	sdp_set_browse_groups(record, root);

	sdp_uuid16_create(&l2cap, L2CAP_UUID);
	proto[0] = sdp_list_append(NULL, &l2cap);
	p = sdp_data_alloc(SDP_UINT16, &psm);
	proto[0] = sdp_list_append(proto[0], p);
	apseq    = sdp_list_append(NULL, proto[0]);

	sdp_uuid16_create(&bnep, BNEP_UUID);
	proto[1] = sdp_list_append(NULL, &bnep);
	v = sdp_data_alloc(SDP_UINT16, &version);
	proto[1] = sdp_list_append(proto[1], v);

	/* Supported protocols */
	{
		uint16_t ptype[] = {
			0x0800,  /* IPv4 */
			0x0806,  /* ARP */
		};
		sdp_data_t *head, *pseq;
		int p;

		for (p = 0, head = NULL; p < 2; p++) {
			sdp_data_t *data = sdp_data_alloc(SDP_UINT16, &ptype[p]);
			if (head)
				sdp_seq_append(head, data);
			else
				head = data;
		}
		pseq = sdp_data_alloc(SDP_SEQ16, head);
		proto[1] = sdp_list_append(proto[1], pseq);
	}

	apseq = sdp_list_append(apseq, proto[1]);

	aproto = sdp_list_append(NULL, apseq);
	sdp_set_access_protos(record, aproto);

	add_lang_attr(record);

	sdp_attr_add_new(record, SDP_ATTR_SECURITY_DESC,
				SDP_UINT16, &security_desc);

	sdp_data_free(p);
	sdp_data_free(v);
	sdp_list_free(apseq, NULL);
	sdp_list_free(root, NULL);
	sdp_list_free(aproto, NULL);
	sdp_list_free(proto[0], NULL);
	sdp_list_free(proto[1], NULL);
	sdp_list_free(svclass, NULL);
	sdp_list_free(pfseq, NULL);

	return record;
}

static ssize_t send_bnep_ctrl_rsp(int sk, uint16_t val)
{
	struct bnep_control_rsp rsp;

	rsp.type = BNEP_CONTROL;
	rsp.ctrl = BNEP_SETUP_CONN_RSP;
	rsp.resp = htons(val);

	return send(sk, &rsp, sizeof(rsp), 0);
}

static int server_connadd(struct network_server *ns, int nsk,
			const gchar *address, uint16_t dst_role)
{
	char devname[16];
	const char *bridge;
	int err;

	/* Server can be disabled in the meantime */
	if (ns->enable == FALSE)
		return -EPERM;

	memset(devname, 0, 16);
	strncpy(devname, prefix, strlen(prefix));

	err = bnep_connadd(nsk, dst_role, devname);
	if (err < 0)
		return err;

	info("Added new connection: %s", devname);

	bridge = bridge_get_name(ns->id);
	if (bridge) {
		if (bridge_add_interface(ns->id, devname) < 0) {
			error("Can't add %s to the bridge %s: %s(%d)",
					devname, bridge, strerror(errno),
					errno);
			return -EPERM;
		}

		bnep_if_up(devname, 0);
	} else
		bnep_if_up(devname, ns->id);

	ns->clients = g_slist_append(ns->clients, g_strdup(address));

	return 0;
}

static void req_auth_cb(DBusError *derr, void *user_data)
{
	struct network_server *ns = user_data;
	uint16_t val;

	if (!setup) {
		info("Authorization cancelled: Client exited");
		return;
	}

	if (derr) {
		error("Access denied: %s", derr->message);
		if (dbus_error_has_name(derr, DBUS_ERROR_NO_REPLY)) {
			bdaddr_t dst;
			str2ba(setup->address, &dst);
			service_cancel_auth(&ns->src, &dst);
		}
		val = BNEP_CONN_NOT_ALLOWED;
		goto done;
	}

	if (server_connadd(ns, setup->nsk,
			setup->address, setup->dst_role) < 0)
		val = BNEP_CONN_NOT_ALLOWED;
	else
		val = BNEP_SUCCESS;

done:
	send_bnep_ctrl_rsp(setup->nsk, val);
	setup_session_free(setup);
	setup = NULL;
}

static int authorize_connection(struct network_server *ns, const char *address)
{
	const char *uuid;
	bdaddr_t dst;
	int ret_val;

	uuid =  bnep_uuid(ns->id);
	str2ba(address, &dst);

	ret_val = service_req_auth(&ns->src, &dst, uuid, req_auth_cb, ns);

	return ret_val;
}

static uint16_t inline bnep_setup_chk(uint16_t dst_role, uint16_t src_role)
{
	/* Allowed PAN Profile scenarios */
	switch (dst_role) {
	case BNEP_SVC_NAP:
	case BNEP_SVC_GN:
		if (src_role == BNEP_SVC_PANU)
			return 0;
		return BNEP_CONN_INVALID_SRC;
	case BNEP_SVC_PANU:
		if (src_role == BNEP_SVC_PANU ||
			src_role == BNEP_SVC_GN ||
			src_role == BNEP_SVC_NAP)
			return 0;

		return BNEP_CONN_INVALID_SRC;
	}

	return BNEP_CONN_INVALID_DST;
}

static uint16_t bnep_setup_decode(struct bnep_setup_conn_req *req,
				uint16_t *dst_role, uint16_t *src_role)
{
	uint8_t *dest, *source;

	dest = req->service;
	source = req->service + req->uuid_size;

	switch (req->uuid_size) {
	case 2: /* UUID16 */
		*dst_role = ntohs(bt_get_unaligned((uint16_t *) dest));
		*src_role = ntohs(bt_get_unaligned((uint16_t *) source));
		break;
	case 4: /* UUID32 */
	case 16: /* UUID128 */
		*dst_role = ntohl(bt_get_unaligned((uint32_t *) dest));
		*src_role = ntohl(bt_get_unaligned((uint32_t *) source));
		break;
	default:
		return BNEP_CONN_INVALID_SVC;
	}

	return 0;
}

static gboolean bnep_setup(GIOChannel *chan,
			GIOCondition cond, gpointer user_data)
{
	struct timeout *to = user_data;
	struct network_server *ns;
	uint8_t packet[BNEP_MTU];
	struct bnep_setup_conn_req *req = (void *) packet;
	struct sockaddr_l2 sa;
	socklen_t size;
	char address[18];
	uint16_t rsp, src_role, dst_role;
	int n, sk;

	if (cond & G_IO_NVAL)
		return FALSE;

	if (cond & (G_IO_ERR | G_IO_HUP)) {
		error("Hangup or error on BNEP socket");
		return FALSE;
	}

	sk = g_io_channel_unix_get_fd(chan);

	/* Reading BNEP_SETUP_CONNECTION_REQUEST_MSG */
	n = read(sk, packet, sizeof(packet));
	if (n < 0) {
		error("read(): %s(%d)", strerror(errno), errno);
		return FALSE;
	}

	if (req->type != BNEP_CONTROL || req->ctrl != BNEP_SETUP_CONN_REQ)
		return FALSE;

	rsp = bnep_setup_decode(req, &dst_role, &src_role);
	if (rsp)
		goto reply;

	rsp = bnep_setup_chk(dst_role, src_role);
	if (rsp)
		goto reply;

	size = sizeof(sa);
	if (getsockname(sk, (struct sockaddr *) &sa, &size) < 0) {
		rsp = BNEP_CONN_NOT_ALLOWED;
		goto reply;
	}

	ba2str(&sa.l2_bdaddr, address);
	ns = server_find(&sa.l2_bdaddr, dst_role);
	if (!ns || ns->enable == FALSE) {
		error("Server unavailable: %s (0x%x)", address, dst_role);
		rsp = BNEP_CONN_NOT_ALLOWED;
		goto reply;
	}

	if (getpeername(sk, (struct sockaddr *) &sa, &size) < 0) {
		rsp = BNEP_CONN_NOT_ALLOWED;
		goto reply;
	}

	ba2str(&sa.l2_bdaddr, address);

	if (setup) {
		error("Connection rejected: Pending authorization");
		rsp = BNEP_CONN_NOT_ALLOWED;
		goto reply;
	}

	setup = setup_session_new(address, dst_role, src_role, sk, to->watch);

	/* Wait authorization before reply success */
	if (authorize_connection(ns, address) < 0) {
		setup_session_free(setup);
		setup = NULL;
		rsp = BNEP_CONN_NOT_ALLOWED;
		goto reply;
	}

	g_source_remove(to->id);
	to->id = 0;

	return TRUE;

reply:
	send_bnep_ctrl_rsp(sk, rsp);

	return FALSE;
}

static void setup_destroy(void *user_data)
{
	struct timeout *to = user_data;

	if (to->id)
		g_source_remove(to->id);

	g_free(to);
}

static gboolean timeout_cb(void *user_data)
{
	struct timeout *to = user_data;

	to->id = 0;
	g_source_remove(to->watch);