ctrl_iface.c

一个Linux下无线网卡的设置工具

 * wpa_supplicant_ctrl_iface_init - Initialize control interface
 * @wpa_s: Pointer to wpa_supplicant data
 * Returns: 0 on success, -1 on failure
 *
 * Initialize the control interface and start receiving commands from external
 * programs.
 */
int wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
{
	CTRL_IFACE_SOCK addr;
	int s = -1;
#ifndef CONFIG_CTRL_IFACE_UDP
	char *fname = NULL;
#endif /* CONFIG_CTRL_IFACE_UDP */

	wpa_s->ctrl_sock = -1;

	if (wpa_s->conf->ctrl_interface == NULL)
		return 0;

#ifdef CONFIG_CTRL_IFACE_UDP
	s = socket(PF_INET, SOCK_DGRAM, 0);
	if (s < 0) {
		perror("socket(PF_INET)");
		goto fail;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl((127 << 24) | 1);
	addr.sin_port = htons(WPA_CTRL_IFACE_PORT);
	if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		perror("bind(AF_INET)");
		goto fail;
	}
#else /* CONFIG_CTRL_IFACE_UDP */
	if (mkdir(wpa_s->conf->ctrl_interface, S_IRWXU | S_IRWXG) < 0) {
		if (errno == EEXIST) {
			wpa_printf(MSG_DEBUG, "Using existing control "
				   "interface directory.");
		} else {
			perror("mkdir[ctrl_interface]");
			goto fail;
		}
	}

	if (wpa_s->conf->ctrl_interface_gid_set &&
	    chown(wpa_s->conf->ctrl_interface, 0,
		  wpa_s->conf->ctrl_interface_gid) < 0) {
		perror("chown[ctrl_interface]");
		return -1;
	}

	if (strlen(wpa_s->conf->ctrl_interface) + 1 + strlen(wpa_s->ifname) >=
	    sizeof(addr.sun_path))
		goto fail;

	s = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (s < 0) {
		perror("socket(PF_UNIX)");
		goto fail;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	fname = wpa_supplicant_ctrl_iface_path(wpa_s);
	if (fname == NULL)
		goto fail;
	strncpy(addr.sun_path, fname, sizeof(addr.sun_path));
	if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		perror("bind(PF_UNIX)");
		if (connect(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
			wpa_printf(MSG_DEBUG, "ctrl_iface exists, but does not"
				   " allow connections - assuming it was left"
				   "over from forced program termination");
			if (unlink(fname) < 0) {
				perror("unlink[ctrl_iface]");
				wpa_printf(MSG_ERROR, "Could not unlink "
					   "existing ctrl_iface socket '%s'",
					   fname);
				goto fail;
			}
			if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) <
			    0) {
				perror("bind(PF_UNIX)");
				goto fail;
			}
			wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
				   "ctrl_iface socket '%s'", fname);
		} else {
			wpa_printf(MSG_INFO, "ctrl_iface exists and seems to "
				   "be in use - cannot override it");
			wpa_printf(MSG_INFO, "Delete '%s' manually if it is "
				   "not used anymore", fname);
			free(fname);
			fname = NULL;
			goto fail;
		}
	}

	if (wpa_s->conf->ctrl_interface_gid_set &&
	    chown(fname, 0, wpa_s->conf->ctrl_interface_gid) < 0) {
		perror("chown[ctrl_interface/ifname]");
		goto fail;
	}

	if (chmod(fname, S_IRWXU | S_IRWXG) < 0) {
		perror("chmod[ctrl_interface/ifname]");
		goto fail;
	}
	free(fname);
#endif /* CONFIG_CTRL_IFACE_UDP */

	wpa_s->ctrl_sock = s;
	eloop_register_read_sock(s, wpa_supplicant_ctrl_iface_receive, wpa_s,
				 NULL);

	return 0;

fail:
	if (s >= 0)
		close(s);
#ifndef CONFIG_CTRL_IFACE_UDP
	if (fname) {
		unlink(fname);
		free(fname);
	}
#endif /* CONFIG_CTRL_IFACE_UDP */
	return -1;
}


/**
 * wpa_supplicant_ctrl_iface_deinit - Deinitialize control interface
 * @wpa_s: Pointer to wpa_supplicant data
 *
 * Deinitialize the control interface that was initialized with
 * wpa_supplicant_ctrl_iface_init().
 */
void wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s)
{
	struct wpa_ctrl_dst *dst, *prev;

	if (wpa_s->ctrl_sock > -1) {
#ifndef CONFIG_CTRL_IFACE_UDP
		char *fname;
#endif /* CONFIG_CTRL_IFACE_UDP */
		eloop_unregister_read_sock(wpa_s->ctrl_sock);
		if (wpa_s->ctrl_dst) {
			/*
			 * Wait a second before closing the control socket if
			 * there are any attached monitors in order to allow
			 * them to receive any pending messages.
			 */
			wpa_printf(MSG_DEBUG, "CTRL_IFACE wait for attached "
				   "monitors to receive messages");
			sleep(1);
		}
		close(wpa_s->ctrl_sock);
		wpa_s->ctrl_sock = -1;
#ifndef CONFIG_CTRL_IFACE_UDP
		fname = wpa_supplicant_ctrl_iface_path(wpa_s);
		if (fname)
			unlink(fname);
		free(fname);

		if (rmdir(wpa_s->conf->ctrl_interface) < 0) {
			if (errno == ENOTEMPTY) {
				wpa_printf(MSG_DEBUG, "Control interface "
					   "directory not empty - leaving it "
					   "behind");
			} else {
				perror("rmdir[ctrl_interface]");
			}
		}
#endif /* CONFIG_CTRL_IFACE_UDP */
	}

	dst = wpa_s->ctrl_dst;
	while (dst) {
		prev = dst;
		dst = dst->next;
		free(prev);
	}
}


/**
 * wpa_supplicant_ctrl_iface_send - Send a control interface packet to monitors
 * @wpa_s: Pointer to wpa_supplicant data
 * @level: Priority level of the message
 * @buf: Message data
 * @len: Message length
 *
 * Send a packet to all monitor programs attached to the control interface.
 */
void wpa_supplicant_ctrl_iface_send(struct wpa_supplicant *wpa_s, int level,
				    char *buf, size_t len)
{
	struct wpa_ctrl_dst *dst, *next;
	char levelstr[10];
	int idx;
#ifdef CONFIG_CTRL_IFACE_UDP
	char *sbuf;
	int llen;

	dst = wpa_s->ctrl_dst;
	if (wpa_s->ctrl_sock < 0 || dst == NULL)
		return;

	snprintf(levelstr, sizeof(levelstr), "<%d>", level);

	llen = strlen(levelstr);
	sbuf = malloc(llen + len);
	if (sbuf == NULL)
		return;

	memcpy(sbuf, levelstr, llen);
	memcpy(sbuf + llen, buf, len);

	idx = 0;
	while (dst) {
		next = dst->next;
		if (level >= dst->debug_level) {
			wpa_printf(MSG_DEBUG, "CTRL_IFACE monitor send %s:%d",
				   inet_ntoa(dst->addr.sin_addr),
				   ntohs(dst->addr.sin_port));
			if (sendto(wpa_s->ctrl_sock, sbuf, llen + len, 0,
				   (struct sockaddr *) &dst->addr,
				   sizeof(dst->addr)) < 0) {
				perror("sendto(CTRL_IFACE monitor)");
				dst->errors++;
				if (dst->errors > 10) {
					wpa_supplicant_ctrl_iface_detach(
						wpa_s, &dst->addr,
						dst->addrlen);
				}
			} else
				dst->errors = 0;
		}
		idx++;
		dst = next;
	}
	free(sbuf);
#else /* CONFIG_CTRL_IFACE_UDP */
	struct msghdr msg;
	struct iovec io[2];

	dst = wpa_s->ctrl_dst;
	if (wpa_s->ctrl_sock < 0 || dst == NULL)
		return;

	snprintf(levelstr, sizeof(levelstr), "<%d>", level);
	io[0].iov_base = levelstr;
	io[0].iov_len = strlen(levelstr);
	io[1].iov_base = buf;
	io[1].iov_len = len;
	memset(&msg, 0, sizeof(msg));
	msg.msg_iov = io;
	msg.msg_iovlen = 2;

	idx = 0;
	while (dst) {
		next = dst->next;
		if (level >= dst->debug_level) {
			wpa_hexdump(MSG_DEBUG, "CTRL_IFACE monitor send",
				    (u8 *) dst->addr.sun_path, dst->addrlen -
				    sizeof(dst->addr.sun_family));
			msg.msg_name = &dst->addr;
			msg.msg_namelen = dst->addrlen;
			if (sendmsg(wpa_s->ctrl_sock, &msg, 0) < 0) {
				perror("sendmsg(CTRL_IFACE monitor)");
				dst->errors++;
				if (dst->errors > 10) {
					wpa_supplicant_ctrl_iface_detach(
						wpa_s, &dst->addr,
						dst->addrlen);
				}
			} else
				dst->errors = 0;
		}
		idx++;
		dst = next;
	}
#endif /* CONFIG_CTRL_IFACE_UDP */
}


/**
 * wpa_supplicant_ctrl_iface_wait - Wait for ctrl_iface monitor
 * @wpa_s: Pointer to wpa_supplicant data
 *
 * Wait until the first message from an external program using the control
 * interface is received. This function can be used to delay normal startup
 * processing to allow control interface programs to attach with
 * %wpa_supplicant before normal operations are started.
 */
void wpa_supplicant_ctrl_iface_wait(struct wpa_supplicant *wpa_s)
{
	fd_set rfds;

	if (wpa_s->ctrl_sock < 0)
		return;

	wpa_printf(MSG_DEBUG, "CTRL_IFACE - %s - wait for monitor",
		   wpa_s->ifname);

	FD_ZERO(&rfds);
	FD_SET(wpa_s->ctrl_sock, &rfds);
	select(wpa_s->ctrl_sock + 1, &rfds, NULL, NULL, NULL);
}


static int wpa_supplicant_global_iface_add(struct wpa_global *global,
					   char *cmd)
{
	struct wpa_interface iface;
	char *pos;

	/*
	 * <ifname>TAB<confname>TAB<driver>TAB<ctrl_interface>TAB<driver_param>
	 */
	wpa_printf(MSG_DEBUG, "CTRL_IFACE GLOBAL INTERFACE_ADD '%s'", cmd);

	memset(&iface, 0, sizeof(iface));

	do {
		iface.ifname = pos = cmd;
		pos = strchr(pos, '\t');
		if (pos)
			*pos++ = '\0';
		if (iface.ifname[0] == '\0')
			return -1;
		if (pos == NULL)
			break;

		iface.confname = pos;
		pos = strchr(pos, '\t');
		if (pos)
			*pos++ = '\0';
		if (iface.confname[0] == '\0')
			iface.confname = NULL;
		if (pos == NULL)
			break;

		iface.driver = pos;
		pos = strchr(pos, '\t');
		if (pos)
			*pos++ = '\0';
		if (iface.driver[0] == '\0')
			iface.driver = NULL;
		if (pos == NULL)
			break;

		iface.ctrl_interface = pos;
		pos = strchr(pos, '\t');
		if (pos)
			*pos++ = '\0';
		if (iface.ctrl_interface[0] == '\0')
			iface.ctrl_interface = NULL;
		if (pos == NULL)
			break;

		iface.driver_param = pos;
		pos = strchr(pos, '\t');
		if (pos)
			*pos++ = '\0';
		if (iface.driver_param[0] == '\0')
			iface.driver_param = NULL;
		if (pos == NULL)
			break;
	} while (0);

	if (wpa_supplicant_get_iface(global, iface.ifname))
		return -1;

	return wpa_supplicant_add_iface(global, &iface) ? 0 : -1;
}


static int wpa_supplicant_global_iface_remove(struct wpa_global *global,
					      char *cmd)
{
	struct wpa_supplicant *wpa_s;

	wpa_printf(MSG_DEBUG, "CTRL_IFACE GLOBAL INTERFACE_REMOVE '%s'", cmd);

	wpa_s = wpa_supplicant_get_iface(global, cmd);
	if (wpa_s == NULL)
		return -1;
	return wpa_supplicant_remove_iface(global, wpa_s);
}


static void wpa_supplicant_global_ctrl_iface_receive(int sock, void *eloop_ctx,
						     void *sock_ctx)
{
	struct wpa_global *global = eloop_ctx;
	char buf[256];
	int res;
	CTRL_IFACE_SOCK from;
	socklen_t fromlen = sizeof(from);
	char *reply;
	const int reply_size = 2048;
	int reply_len;

	res = recvfrom(sock, buf, sizeof(buf) - 1, 0,
		       (struct sockaddr *) &from, &fromlen);
	if (res < 0) {
		perror("recvfrom(ctrl_iface)");
		return;
	}
	buf[res] = '\0';
	wpa_hexdump_ascii(MSG_DEBUG, "RX global ctrl_iface", (u8 *) buf, res);

	reply = malloc(reply_size);
	if (reply == NULL) {
		sendto(sock, "FAIL\n", 5, 0, (struct sockaddr *) &from,
		       fromlen);
		return;
	}

	memcpy(reply, "OK\n", 3);
	reply_len = 3;

	if (strcmp(buf, "PING") == 0) {
		memcpy(reply, "PONG\n", 5);
		reply_len = 5;
	} else if (strncmp(buf, "INTERFACE_ADD ", 14) == 0) {
		if (wpa_supplicant_global_iface_add(global, buf + 14))
			reply_len = -1;
	} else if (strncmp(buf, "INTERFACE_REMOVE ", 17) == 0) {
		if (wpa_supplicant_global_iface_remove(global, buf + 17))
			reply_len = -1;
	} else {
		memcpy(reply, "UNKNOWN COMMAND\n", 16);
		reply_len = 16;
	}

	if (reply_len < 0) {
		memcpy(reply, "FAIL\n", 5);
		reply_len = 5;
	}
	sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from, fromlen);
	free(reply);
}


/**
 * wpa_supplicant_global_ctrl_iface_init - Initialize global control interface
 * @global: Pointer to global data from wpa_supplicant_init()
 * Returns: 0 on success, -1 on failure
 *
 * Initialize the global control interface and start receiving commands from
 * external programs.
 */
int wpa_supplicant_global_ctrl_iface_init(struct wpa_global *global)
{
	CTRL_IFACE_SOCK addr;
	int s = -1;

	global->ctrl_sock = -1;

	if (global->params.ctrl_interface == NULL)
		return 0;

	wpa_printf(MSG_DEBUG, "Global control interface '%s'",
		   global->params.ctrl_interface);

#ifdef CONFIG_CTRL_IFACE_UDP
	s = socket(PF_INET, SOCK_DGRAM, 0);
	if (s < 0) {
		perror("socket(PF_INET)");
		goto fail;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl((127 << 24) | 1);
	addr.sin_port = htons(WPA_GLOBAL_CTRL_IFACE_PORT);
	if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		perror("bind(AF_INET)");
		goto fail;
	}
#else /* CONFIG_CTRL_IFACE_UDP */
	s = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (s < 0) {
		perror("socket(PF_UNIX)");
		goto fail;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	strncpy(addr.sun_path, global->params.ctrl_interface,
		sizeof(addr.sun_path));
	if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		perror("bind(PF_UNIX)");
		if (connect(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
			wpa_printf(MSG_DEBUG, "ctrl_iface exists, but does not"
				   " allow connections - assuming it was left"
				   "over from forced program termination");
			if (unlink(global->params.ctrl_interface) < 0) {
				perror("unlink[ctrl_iface]");
				wpa_printf(MSG_ERROR, "Could not unlink "
					   "existing ctrl_iface socket '%s'",
					   global->params.ctrl_interface);
				goto fail;
			}
			if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) <
			    0) {
				perror("bind(PF_UNIX)");
				goto fail;
			}
			wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
				   "ctrl_iface socket '%s'",
				   global->params.ctrl_interface);
		} else {
			wpa_printf(MSG_INFO, "ctrl_iface exists and seems to "
				   "be in use - cannot override it");
			wpa_printf(MSG_INFO, "Delete '%s' manually if it is "
				   "not used anymore",
				   global->params.ctrl_interface);
			goto fail;
		}
	}
#endif /* CONFIG_CTRL_IFACE_UDP */

	global->ctrl_sock = s;
	eloop_register_read_sock(s, wpa_supplicant_global_ctrl_iface_receive,
				 global, NULL);

	return 0;

fail:
	if (s >= 0)
		close(s);
	return -1;
}


/**
 * wpa_supplicant_global_ctrl_iface_deinit - Deinitialize global ctrl interface
 * @global: Pointer to global data from wpa_supplicant_init()
 *
 * Deinitialize the global control interface that was initialized with
 * wpa_supplicant_global_ctrl_iface_init().
 */
void wpa_supplicant_global_ctrl_iface_deinit(struct wpa_global *global)
{
	if (global->ctrl_sock < 0)
		return;

	eloop_unregister_read_sock(global->ctrl_sock);
	close(global->ctrl_sock);
	global->ctrl_sock = -1;

#ifndef CONFIG_CTRL_IFACE_UDP
	if (global->params.ctrl_interface)
		unlink(global->params.ctrl_interface);
#endif /* CONFIG_CTRL_IFACE_UDP */
}