/*
 * WPA Supplicant / UNIX domain socket -based control interface
 * Copyright (c) 2004-2020, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"
#include <sys/un.h>
#include <sys/stat.h>
#include <grp.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#ifdef __linux__
#include <sys/ioctl.h>
#endif /* __linux__ */
#ifdef ANDROID
#include <cutils/sockets.h>
#endif /* ANDROID */

#include "utils/common.h"
#include "utils/eloop.h"
#include "utils/list.h"
#include "common/ctrl_iface_common.h"
#include "eapol_supp/eapol_supp_sm.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "ctrl_iface.h"

/* Per-interface ctrl_iface */

struct ctrl_iface_priv {
	struct wpa_supplicant *wpa_s;
	int sock;
	struct dl_list ctrl_dst;
	int android_control_socket;
	struct dl_list msg_queue;
	unsigned int throttle_count;
};


struct ctrl_iface_global_priv {
	struct wpa_global *global;
	int sock;
	struct dl_list ctrl_dst;
	int android_control_socket;
	struct dl_list msg_queue;
	unsigned int throttle_count;
};

struct ctrl_iface_msg {
	struct dl_list list;
	struct wpa_supplicant *wpa_s;
	int level;
	enum wpa_msg_type type;
	const char *txt;
	size_t len;
};


static void wpa_supplicant_ctrl_iface_send(struct wpa_supplicant *wpa_s,
					   const char *ifname, int sock,
					   struct dl_list *ctrl_dst,
					   int level, const char *buf,
					   size_t len,
					   struct ctrl_iface_priv *priv,
					   struct ctrl_iface_global_priv *gp);
static int wpas_ctrl_iface_reinit(struct wpa_supplicant *wpa_s,
				  struct ctrl_iface_priv *priv);
static int wpas_ctrl_iface_global_reinit(struct wpa_global *global,
					 struct ctrl_iface_global_priv *priv);


static void wpas_ctrl_sock_debug(const char *title, int sock, const char *buf,
				 size_t len)
{
#ifdef __linux__
	socklen_t optlen;
	int sndbuf, outq;
	int level = MSG_MSGDUMP;

	if (len >= 5 && os_strncmp(buf, "PONG\n", 5) == 0)
		level = MSG_EXCESSIVE;

	optlen = sizeof(sndbuf);
	sndbuf = 0;
	if (getsockopt(sock, SOL_SOCKET, SO_SNDBUF, &sndbuf, &optlen) < 0)
		sndbuf = -1;

	if (ioctl(sock, TIOCOUTQ, &outq) < 0)
		outq = -1;

	wpa_printf(level,
		   "CTRL-DEBUG: %s: sock=%d sndbuf=%d outq=%d send_len=%d",
		   title, sock, sndbuf, outq, (int) len);
#endif /* __linux__ */
}


static int wpa_supplicant_ctrl_iface_attach(struct dl_list *ctrl_dst,
					    struct sockaddr_storage *from,
					    socklen_t fromlen, int global)
{
	return ctrl_iface_attach(ctrl_dst, from, fromlen, NULL);
}


static int wpa_supplicant_ctrl_iface_detach(struct dl_list *ctrl_dst,
					    struct sockaddr_storage *from,
					    socklen_t fromlen)
{
	return ctrl_iface_detach(ctrl_dst, from, fromlen);
}


static int wpa_supplicant_ctrl_iface_level(struct ctrl_iface_priv *priv,
					   struct sockaddr_storage *from,
					   socklen_t fromlen,
					   char *level)
{
	wpa_printf(MSG_DEBUG, "CTRL_IFACE LEVEL %s", level);

	return ctrl_iface_level(&priv->ctrl_dst, from, fromlen, level);
}


static void wpa_supplicant_ctrl_iface_receive(int sock, void *eloop_ctx,
					      void *sock_ctx)
{
	struct wpa_supplicant *wpa_s = eloop_ctx;
	struct ctrl_iface_priv *priv = sock_ctx;
	char *buf;
	int res;
	struct sockaddr_storage from;
	socklen_t fromlen = sizeof(from);
	char *reply = NULL, *reply_buf = NULL;
	size_t reply_len = 0;
	int new_attached = 0;

	buf = os_malloc(CTRL_IFACE_MAX_LEN + 1);
	if (!buf)
		return;
	res = recvfrom(sock, buf, CTRL_IFACE_MAX_LEN + 1, 0,
		       (struct sockaddr *) &from, &fromlen);
	if (res < 0) {
		wpa_printf(MSG_ERROR, "recvfrom(ctrl_iface): %s",
			   strerror(errno));
		os_free(buf);
		return;
	}
	if ((size_t) res > CTRL_IFACE_MAX_LEN) {
		wpa_printf(MSG_ERROR, "recvform(ctrl_iface): input truncated");
		os_free(buf);
		return;
	}
	buf[res] = '\0';

	if (os_strcmp(buf, "ATTACH") == 0) {
		if (wpa_supplicant_ctrl_iface_attach(&priv->ctrl_dst, &from,
						     fromlen, 0))
			reply_len = 1;
		else {
			new_attached = 1;
			reply_len = 2;
		}
	} else if (os_strcmp(buf, "DETACH") == 0) {
		if (wpa_supplicant_ctrl_iface_detach(&priv->ctrl_dst, &from,
						     fromlen))
			reply_len = 1;
		else
			reply_len = 2;
	} else if (os_strncmp(buf, "LEVEL ", 6) == 0) {
		if (wpa_supplicant_ctrl_iface_level(priv, &from, fromlen,
						    buf + 6))
			reply_len = 1;
		else
			reply_len = 2;
	} else {
		sockaddr_print(wpas_ctrl_cmd_debug_level(buf),
			       "Control interface recv command from:",
			       &from, fromlen);
		reply_buf = wpa_supplicant_ctrl_iface_process(wpa_s, buf,
							      &reply_len);
		reply = reply_buf;

		/*
		 * There could be some password/key material in the command, so
		 * clear the buffer explicitly now that it is not needed
		 * anymore.
		 */
		os_memset(buf, 0, res);
	}

	if (!reply && reply_len == 1) {
		reply = "FAIL\n";
		reply_len = 5;
	} else if (!reply && reply_len == 2) {
		reply = "OK\n";
		reply_len = 3;
	}

	if (reply) {
		wpas_ctrl_sock_debug("ctrl_sock-sendto", sock, reply,
				     reply_len);
		if (sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from,
			   fromlen) < 0) {
			int _errno = errno;
			wpa_dbg(wpa_s, MSG_DEBUG,
				"ctrl_iface sendto failed: %d - %s",
				_errno, strerror(_errno));
			if (_errno == ENOBUFS || _errno == EAGAIN) {
				/*
				 * The socket send buffer could be full. This
				 * may happen if client programs are not
				 * receiving their pending messages. Close and
				 * reopen the socket as a workaround to avoid
				 * getting stuck being unable to send any new
				 * responses.
				 */
				sock = wpas_ctrl_iface_reinit(wpa_s, priv);
				if (sock < 0) {
					wpa_dbg(wpa_s, MSG_DEBUG, "Failed to reinitialize ctrl_iface socket");
				}
			}
			if (new_attached) {
				wpa_dbg(wpa_s, MSG_DEBUG, "Failed to send response to ATTACH - detaching");
				new_attached = 0;
				wpa_supplicant_ctrl_iface_detach(
					&priv->ctrl_dst, &from, fromlen);
			}
		}
	}
	os_free(reply_buf);
	os_free(buf);

	if (new_attached)
		eapol_sm_notify_ctrl_attached(wpa_s->eapol);
}


static char * wpa_supplicant_ctrl_iface_path(struct wpa_supplicant *wpa_s)
{
	char *buf;
	size_t len;
	char *pbuf, *dir = NULL;
	int res;

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

	pbuf = os_strdup(wpa_s->conf->ctrl_interface);
	if (pbuf == NULL)
		return NULL;
	if (os_strncmp(pbuf, "DIR=", 4) == 0) {
		char *gid_str;
		dir = pbuf + 4;
		gid_str = os_strstr(dir, " GROUP=");
		if (gid_str)
			*gid_str = '\0';
	} else
		dir = pbuf;

	len = os_strlen(dir) + os_strlen(wpa_s->ifname) + 2;
	buf = os_malloc(len);
	if (buf == NULL) {
		os_free(pbuf);
		return NULL;
	}

	res = os_snprintf(buf, len, "%s/%s", dir, wpa_s->ifname);
	if (os_snprintf_error(len, res)) {
		os_free(pbuf);
		os_free(buf);
		return NULL;
	}
#ifdef __CYGWIN__
	{
		/* Windows/WinPcap uses interface names that are not suitable
		 * as a file name - convert invalid chars to underscores */
		char *pos = buf;
		while (*pos) {
			if (*pos == '\\')
				*pos = '_';
			pos++;
		}
	}
#endif /* __CYGWIN__ */
	os_free(pbuf);
	return buf;
}


static int wpas_ctrl_iface_throttle(int sock)
{
#ifdef __linux__
	socklen_t optlen;
	int sndbuf, outq;

	optlen = sizeof(sndbuf);
	sndbuf = 0;
	if (getsockopt(sock, SOL_SOCKET, SO_SNDBUF, &sndbuf, &optlen) < 0 ||
	    ioctl(sock, TIOCOUTQ, &outq) < 0 ||
	    sndbuf <= 0 || outq < 0)
		return 0;
	return outq > sndbuf / 2;
#else /* __linux__ */
	return 0;
#endif /* __linux__ */
}


static void wpas_ctrl_msg_send_pending_global(struct wpa_global *global)
{
	struct ctrl_iface_global_priv *gpriv;
	struct ctrl_iface_msg *msg;

	gpriv = global->ctrl_iface;
	while (gpriv && !dl_list_empty(&gpriv->msg_queue) &&
	       !wpas_ctrl_iface_throttle(gpriv->sock)) {
		msg = dl_list_first(&gpriv->msg_queue, struct ctrl_iface_msg,
				    list);
		if (!msg)
			break;
		dl_list_del(&msg->list);
		wpa_supplicant_ctrl_iface_send(
			msg->wpa_s,
			msg->type != WPA_MSG_PER_INTERFACE ?
			NULL : msg->wpa_s->ifname,
			gpriv->sock, &gpriv->ctrl_dst, msg->level,
			msg->txt, msg->len, NULL, gpriv);
		os_free(msg);
	}
}


static void wpas_ctrl_msg_send_pending_iface(struct wpa_supplicant *wpa_s)
{
	struct ctrl_iface_priv *priv;
	struct ctrl_iface_msg *msg;

	priv = wpa_s->ctrl_iface;
	while (priv && !dl_list_empty(&priv->msg_queue) &&
	       !wpas_ctrl_iface_throttle(priv->sock)) {
		msg = dl_list_first(&priv->msg_queue, struct ctrl_iface_msg,
				    list);
		if (!msg)
			break;
		dl_list_del(&msg->list);
		wpa_supplicant_ctrl_iface_send(wpa_s, NULL, priv->sock,
					       &priv->ctrl_dst, msg->level,
					       msg->txt, msg->len, priv, NULL);
		os_free(msg);
	}
}


static void wpas_ctrl_msg_queue_timeout(void *eloop_ctx, void *timeout_ctx)
{
	struct wpa_supplicant *wpa_s = eloop_ctx;
	struct ctrl_iface_priv *priv;
	struct ctrl_iface_global_priv *gpriv;
	int sock = -1, gsock = -1;

	wpas_ctrl_msg_send_pending_global(wpa_s->global);
	wpas_ctrl_msg_send_pending_iface(wpa_s);

	priv = wpa_s->ctrl_iface;
	if (priv && !dl_list_empty(&priv->msg_queue))
		sock = priv->sock;

	gpriv = wpa_s->global->ctrl_iface;
	if (gpriv && !dl_list_empty(&gpriv->msg_queue))
		gsock = gpriv->sock;

	if (sock > -1 || gsock > -1) {
		/* Continue pending message transmission from a timeout */
		wpa_printf(MSG_MSGDUMP,
			   "CTRL: Had to throttle pending event message transmission for (sock %d gsock %d)",
			   sock, gsock);
		eloop_register_timeout(0, 20000, wpas_ctrl_msg_queue_timeout,
				       wpa_s, NULL);
	}
}


static void wpas_ctrl_msg_queue(struct dl_list *queue,
				struct wpa_supplicant *wpa_s, int level,
				enum wpa_msg_type type,
				const char *txt, size_t len)
{
	struct ctrl_iface_msg *msg;

	msg = os_zalloc(sizeof(*msg) + len);
	if (!msg)
		return;

	msg->wpa_s = wpa_s;
	msg->level = level;
	msg->type = type;
	os_memcpy(msg + 1, txt, len);
	msg->txt = (const char *) (msg + 1);
	msg->len = len;
	dl_list_add_tail(queue, &msg->list);
	eloop_cancel_timeout(wpas_ctrl_msg_queue_timeout, wpa_s, NULL);
	eloop_register_timeout(0, 0, wpas_ctrl_msg_queue_timeout, wpa_s, NULL);
}


static void wpas_ctrl_msg_queue_limit(unsigned int throttle_count,
				      struct dl_list *queue)
{
	struct ctrl_iface_msg *msg;

	if (throttle_count < 2000)
		return;

	msg = dl_list_first(queue, struct ctrl_iface_msg, list);
	if (msg) {
		wpa_printf(MSG_DEBUG, "CTRL: Dropped oldest pending message");
		dl_list_del(&msg->list);
		os_free(msg);
	}
}


static void wpa_supplicant_ctrl_iface_msg_cb(void *ctx, int level,
					     enum wpa_msg_type type,
					     const char *txt, size_t len)
{
	struct wpa_supplicant *wpa_s = ctx;
	struct ctrl_iface_priv *priv;
	struct ctrl_iface_global_priv *gpriv;

	if (wpa_s == NULL)
		return;

	gpriv = wpa_s->global->ctrl_iface;

	if (type != WPA_MSG_NO_GLOBAL && gpriv &&
	    !dl_list_empty(&gpriv->ctrl_dst)) {
		if (!dl_list_empty(&gpriv->msg_queue) ||
		    wpas_ctrl_iface_throttle(gpriv->sock)) {
			if (gpriv->throttle_count == 0) {
				wpa_printf(MSG_MSGDUMP,
					   "CTRL: Had to throttle global event message for sock %d",
					   gpriv->sock);
			}
			gpriv->throttle_count++;
			wpas_ctrl_msg_queue_limit(gpriv->throttle_count,
						  &gpriv->msg_queue);
			wpas_ctrl_msg_queue(&gpriv->msg_queue, wpa_s, level,
					    type, txt, len);
		} else {
			if (gpriv->throttle_count) {
				wpa_printf(MSG_MSGDUMP,
					   "CTRL: Had to throttle %u global event message(s) for sock %d",
					   gpriv->throttle_count, gpriv->sock);
			}
			gpriv->throttle_count = 0;
			wpa_supplicant_ctrl_iface_send(
				wpa_s,
				type != WPA_MSG_PER_INTERFACE ?
				NULL : wpa_s->ifname,
				gpriv->sock, &gpriv->ctrl_dst, level,
				txt, len, NULL, gpriv);
		}
	}

	priv = wpa_s->ctrl_iface;

	if (type != WPA_MSG_ONLY_GLOBAL && priv) {
		if (!dl_list_empty(&priv->msg_queue) ||
		    wpas_ctrl_iface_throttle(priv->sock)) {
			if (priv->throttle_count == 0) {
				wpa_printf(MSG_MSGDUMP,
					   "CTRL: Had to throttle event message for sock %d",
					   priv->sock);
			}
			priv->throttle_count++;
			wpas_ctrl_msg_queue_limit(priv->throttle_count,
						  &priv->msg_queue);
			wpas_ctrl_msg_queue(&priv->msg_queue, wpa_s, level,
					    type, txt, len);
		} else {
			if (priv->throttle_count) {
				wpa_printf(MSG_MSGDUMP,
					   "CTRL: Had to throttle %u event message(s) for sock %d",
					   priv->throttle_count, priv->sock);
			}
			priv->throttle_count = 0;
			wpa_supplicant_ctrl_iface_send(wpa_s, NULL, priv->sock,
						       &priv->ctrl_dst, level,
						       txt, len, priv, NULL);
		}
	}
}


static int wpas_ctrl_iface_open_sock(struct wpa_supplicant *wpa_s,
				     struct ctrl_iface_priv *priv)
{
	struct sockaddr_un addr;
	char *fname = NULL;
	gid_t gid = 0;
	int gid_set = 0;
	char *buf, *dir = NULL, *gid_str = NULL;
	struct group *grp;
	char *endp;
	int flags;
#if defined(__FreeBSD__)
	int optval, rc;
	socklen_t optlen;
#endif

	buf = os_strdup(wpa_s->conf->ctrl_interface);
	if (buf == NULL)
		goto fail;
#ifdef ANDROID
	os_snprintf(addr.sun_path, sizeof(addr.sun_path), "wpa_%s",
		    wpa_s->conf->ctrl_interface);
	priv->sock = android_get_control_socket(addr.sun_path);
	if (priv->sock >= 0) {
		priv->android_control_socket = 1;
		goto havesock;
	}
#endif /* ANDROID */
	if (os_strncmp(buf, "DIR=", 4) == 0) {
		dir = buf + 4;
		gid_str = os_strstr(dir, " GROUP=");
		if (gid_str) {
			*gid_str = '\0';
			gid_str += 7;
		}
	} else {
		dir = buf;
		gid_str = wpa_s->conf->ctrl_interface_group;
	}

	if (mkdir(dir, S_IRWXU | S_IRWXG) < 0) {
		if (errno == EEXIST) {
			wpa_printf(MSG_DEBUG, "Using existing control "
				   "interface directory.");
		} else {
			wpa_printf(MSG_ERROR, "mkdir[ctrl_interface=%s]: %s",
				   dir, strerror(errno));
			goto fail;
		}
	}

#ifdef ANDROID
	/*
	 * wpa_supplicant is started from /init.*.rc on Android and that seems
	 * to be using umask 0077 which would leave the control interface
	 * directory without group access. This breaks things since Wi-Fi
	 * framework assumes that this directory can be accessed by other
	 * applications in the wifi group. Fix this by adding group access even
	 * if umask value would prevent this.
	 */
	if (chmod(dir, S_IRWXU | S_IRWXG) < 0) {
		wpa_printf(MSG_ERROR, "CTRL: Could not chmod directory: %s",
			   strerror(errno));
		/* Try to continue anyway */
	}
#endif /* ANDROID */

	if (gid_str) {
		grp = getgrnam(gid_str);
		if (grp) {
			gid = grp->gr_gid;
			gid_set = 1;
			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d"
				   " (from group name '%s')",
				   (int) gid, gid_str);
		} else {
			/* Group name not found - try to parse this as gid */
			gid = strtol(gid_str, &endp, 10);
			if (*gid_str == '\0' || *endp != '\0') {
				wpa_printf(MSG_ERROR, "CTRL: Invalid group "
					   "'%s'", gid_str);
				goto fail;
			}
			gid_set = 1;
			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d",
				   (int) gid);
		}
	}

	if (gid_set && lchown(dir, -1, gid) < 0) {
		wpa_printf(MSG_ERROR, "lchown[ctrl_interface=%s,gid=%d]: %s",
			   dir, (int) gid, strerror(errno));
		goto fail;
	}

	/* Make sure the group can enter and read the directory */
	if (gid_set &&
	    chmod(dir, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP) < 0) {
		wpa_printf(MSG_ERROR, "CTRL: chmod[ctrl_interface]: %s",
			   strerror(errno));
		goto fail;
	}

	if (os_strlen(dir) + 1 + os_strlen(wpa_s->ifname) >=
	    sizeof(addr.sun_path)) {
		wpa_printf(MSG_ERROR, "ctrl_iface path limit exceeded");
		goto fail;
	}

	priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (priv->sock < 0) {
		wpa_printf(MSG_ERROR, "socket(PF_UNIX): %s", strerror(errno));
		goto fail;
	}

	os_memset(&addr, 0, sizeof(addr));
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	addr.sun_len = sizeof(addr);
#endif /* __FreeBSD__ */
	addr.sun_family = AF_UNIX;
	fname = wpa_supplicant_ctrl_iface_path(wpa_s);
	if (fname == NULL)
		goto fail;
	os_strlcpy(addr.sun_path, fname, sizeof(addr.sun_path));
	if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		wpa_printf(MSG_DEBUG, "ctrl_iface bind(PF_UNIX) failed: %s",
			   strerror(errno));
		if (connect(priv->sock, (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) {
				wpa_printf(MSG_ERROR,
					   "Could not unlink existing ctrl_iface socket '%s': %s",
					   fname, strerror(errno));
				goto fail;
			}
			if (bind(priv->sock, (struct sockaddr *) &addr,
				 sizeof(addr)) < 0) {
				wpa_printf(MSG_ERROR, "supp-ctrl-iface-init: bind(PF_UNIX): %s",
					   strerror(errno));
				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);
			os_free(fname);
			fname = NULL;
			goto fail;
		}
	}

	if (gid_set && lchown(fname, -1, gid) < 0) {
		wpa_printf(MSG_ERROR, "lchown[ctrl_interface=%s,gid=%d]: %s",
			   fname, (int) gid, strerror(errno));
		goto fail;
	}

	if (chmod(fname, S_IRWXU | S_IRWXG) < 0) {
		wpa_printf(MSG_ERROR, "chmod[ctrl_interface=%s]: %s",
			   fname, strerror(errno));
		goto fail;
	}
	os_free(fname);

#ifdef ANDROID
havesock:
#endif /* ANDROID */

	/*
	 * Make socket non-blocking so that we don't hang forever if
	 * target dies unexpectedly.
	 */
	flags = fcntl(priv->sock, F_GETFL);
	if (flags >= 0) {
		flags |= O_NONBLOCK;
		if (fcntl(priv->sock, F_SETFL, flags) < 0) {
			wpa_printf(MSG_INFO, "fcntl(ctrl, O_NONBLOCK): %s",
				   strerror(errno));
			/* Not fatal, continue on.*/
		}
	}

#if defined(__FreeBSD__)
	/* Ensure we can send a full length message atomically. */
	optval = 0;
	optlen = sizeof(optval);
	if (getsockopt(priv->sock, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) == -1) {
		wpa_printf(MSG_INFO, "failed to get sndbuf for sock=%d: %s",
			   priv->sock, strerror(errno));
	} else if (optval < CTRL_IFACE_MAX_LEN) {
		optval = CTRL_IFACE_MAX_LEN;
		if (setsockopt(priv->sock, SOL_SOCKET, SO_SNDBUF, &optval,
			       sizeof(optval)) == -1)
			wpa_printf(MSG_ERROR, "failed to set sndbuf for "
				   "sock=%d: %s", priv->sock, strerror(errno));
	}
#endif

	eloop_register_read_sock(priv->sock, wpa_supplicant_ctrl_iface_receive,
				 wpa_s, priv);
	wpa_msg_register_cb(wpa_supplicant_ctrl_iface_msg_cb);

	os_free(buf);
	return 0;

fail:
	if (priv->sock >= 0) {
		close(priv->sock);
		priv->sock = -1;
	}
	if (fname) {
		unlink(fname);
		os_free(fname);
	}
	os_free(buf);
	return -1;
}


struct ctrl_iface_priv *
wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
{
	struct ctrl_iface_priv *priv;

	priv = os_zalloc(sizeof(*priv));
	if (priv == NULL)
		return NULL;
	dl_list_init(&priv->ctrl_dst);
	dl_list_init(&priv->msg_queue);
	priv->wpa_s = wpa_s;
	priv->sock = -1;

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

#ifdef ANDROID
	if (wpa_s->global->params.ctrl_interface) {
		int same = 0;

		if (wpa_s->global->params.ctrl_interface[0] == '/') {
			if (os_strcmp(wpa_s->global->params.ctrl_interface,
				      wpa_s->conf->ctrl_interface) == 0)
				same = 1;
		} else if (os_strncmp(wpa_s->global->params.ctrl_interface,
				      "@android:", 9) == 0 ||
			   os_strncmp(wpa_s->global->params.ctrl_interface,
				      "@abstract:", 10) == 0) {
			char *pos;

			/*
			 * Currently, Android uses @android:wpa_* as the naming
			 * convention for the global ctrl interface. This logic
			 * needs to be revisited if the above naming convention
			 * is modified.
			 */
			pos = os_strchr(wpa_s->global->params.ctrl_interface,
					'_');
			if (pos &&
			    os_strcmp(pos + 1,
				      wpa_s->conf->ctrl_interface) == 0)
				same = 1;
		}

		if (same) {
			/*
			 * The invalid configuration combination might be
			 * possible to hit in an Android OTA upgrade case, so
			 * instead of refusing to start the wpa_supplicant
			 * process, do not open the per-interface ctrl_iface
			 * and continue with the global control interface that
			 * was set from the command line since the Wi-Fi
			 * framework will use it for operations.
			 */
			wpa_printf(MSG_ERROR,
				   "global ctrl interface %s matches ctrl interface %s - do not open per-interface ctrl interface",
				   wpa_s->global->params.ctrl_interface,
				   wpa_s->conf->ctrl_interface);
			return priv;
		}
	}
#endif /* ANDROID */

	if (wpas_ctrl_iface_open_sock(wpa_s, priv) < 0) {
		os_free(priv);
		return NULL;
	}

	return priv;
}


static int wpas_ctrl_iface_reinit(struct wpa_supplicant *wpa_s,
				  struct ctrl_iface_priv *priv)
{
	int res;

	if (priv->sock <= 0)
		return -1;

	/*
	 * On Android, the control socket being used may be the socket
	 * that is created when wpa_supplicant is started as a /init.*.rc
	 * service. Such a socket is maintained as a key-value pair in
	 * Android's environment. Closing this control socket would leave us
	 * in a bad state with an invalid socket descriptor.
	 */
	if (priv->android_control_socket)
		return priv->sock;

	eloop_unregister_read_sock(priv->sock);
	close(priv->sock);
	priv->sock = -1;
	res = wpas_ctrl_iface_open_sock(wpa_s, priv);
	if (res < 0)
		return -1;
	return priv->sock;
}


static void
wpas_global_ctrl_iface_flush_queued_msg(struct wpa_global *global,
					struct wpa_supplicant *wpa_s)
{
	struct ctrl_iface_global_priv *gpriv;
	struct ctrl_iface_msg *msg, *prev_msg;
	unsigned int count = 0;

	if (!global || !global->ctrl_iface)
		return;

	gpriv = global->ctrl_iface;
	dl_list_for_each_safe(msg, prev_msg, &gpriv->msg_queue,
			      struct ctrl_iface_msg, list) {
		if (msg->wpa_s == wpa_s) {
			count++;
			dl_list_del(&msg->list);
			os_free(msg);
		}
	}

	if (count) {
		wpa_printf(MSG_DEBUG,
			   "CTRL: Dropped %u pending message(s) for interface that is being removed",
			count);
	}
}


void wpa_supplicant_ctrl_iface_deinit(struct wpa_supplicant *wpa_s,
				      struct ctrl_iface_priv *priv)
{
	struct wpa_ctrl_dst *dst, *prev;
	struct ctrl_iface_msg *msg, *prev_msg;
	struct ctrl_iface_global_priv *gpriv;

	if (!priv) {
		/* Control interface has not yet been initialized, so there is
		 * nothing to deinitialize here. However, there might be a
		 * pending message for this interface, so get rid of any such
		 * entry before completing interface removal. */
		wpas_global_ctrl_iface_flush_queued_msg(wpa_s->global, wpa_s);
		eloop_cancel_timeout(wpas_ctrl_msg_queue_timeout, wpa_s, NULL);
		return;
	}

	if (priv->sock > -1) {
		char *fname;
		char *buf, *dir = NULL;
		eloop_unregister_read_sock(priv->sock);
		if (!dl_list_empty(&priv->ctrl_dst)) {
			/*
			 * Wait 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");
			os_sleep(0, 100000);
		}
		close(priv->sock);
		priv->sock = -1;
		fname = wpa_supplicant_ctrl_iface_path(priv->wpa_s);
		if (fname) {
			unlink(fname);
			os_free(fname);
		}

		if (priv->wpa_s->conf->ctrl_interface == NULL)
			goto free_dst;
		buf = os_strdup(priv->wpa_s->conf->ctrl_interface);
		if (buf == NULL)
			goto free_dst;
		if (os_strncmp(buf, "DIR=", 4) == 0) {
			char *gid_str;
			dir = buf + 4;
			gid_str = os_strstr(dir, " GROUP=");
			if (gid_str)
				*gid_str = '\0';
		} else
			dir = buf;

		if (rmdir(dir) < 0) {
			if (errno == ENOTEMPTY) {
				wpa_printf(MSG_DEBUG, "Control interface "
					   "directory not empty - leaving it "
					   "behind");
			} else {
				wpa_printf(MSG_ERROR,
					   "rmdir[ctrl_interface=%s]: %s",
					   dir, strerror(errno));
			}
		}
		os_free(buf);
	}

free_dst:
	dl_list_for_each_safe(dst, prev, &priv->ctrl_dst, struct wpa_ctrl_dst,
			      list) {
		dl_list_del(&dst->list);
		os_free(dst);
	}
	dl_list_for_each_safe(msg, prev_msg, &priv->msg_queue,
			      struct ctrl_iface_msg, list) {
		dl_list_del(&msg->list);
		os_free(msg);
	}
	gpriv = priv->wpa_s->global->ctrl_iface;
	if (gpriv) {
		dl_list_for_each_safe(msg, prev_msg, &gpriv->msg_queue,
				      struct ctrl_iface_msg, list) {
			if (msg->wpa_s == priv->wpa_s) {
				dl_list_del(&msg->list);
				os_free(msg);
			}
		}
	}
	wpas_global_ctrl_iface_flush_queued_msg(wpa_s->global, wpa_s);
	eloop_cancel_timeout(wpas_ctrl_msg_queue_timeout, priv->wpa_s, NULL);
	os_free(priv);
}


/**
 * wpa_supplicant_ctrl_iface_send - Send a control interface packet to monitors
 * @ifname: Interface name for global control socket or %NULL
 * @sock: Local socket fd
 * @ctrl_dst: List of attached listeners
 * @level: Priority level of the message
 * @buf: Message data
 * @len: Message length
 *
 * Send a packet to all monitor programs attached to the control interface.
 */
static void wpa_supplicant_ctrl_iface_send(struct wpa_supplicant *wpa_s,
					   const char *ifname, int sock,
					   struct dl_list *ctrl_dst,
					   int level, const char *buf,
					   size_t len,
					   struct ctrl_iface_priv *priv,
					   struct ctrl_iface_global_priv *gp)
{
	struct wpa_ctrl_dst *dst, *next;
	char levelstr[10];
	int idx, res;
	struct msghdr msg;
	struct iovec io[5];

	if (sock < 0 || dl_list_empty(ctrl_dst))
		return;

	res = os_snprintf(levelstr, sizeof(levelstr), "<%d>", level);
	if (os_snprintf_error(sizeof(levelstr), res))
		return;
	idx = 0;
	if (ifname) {
		io[idx].iov_base = "IFNAME=";
		io[idx].iov_len = 7;
		idx++;
		io[idx].iov_base = (char *) ifname;
		io[idx].iov_len = os_strlen(ifname);
		idx++;
		io[idx].iov_base = " ";
		io[idx].iov_len = 1;
		idx++;
	}
	io[idx].iov_base = levelstr;
	io[idx].iov_len = os_strlen(levelstr);
	idx++;
	io[idx].iov_base = (char *) buf;
	io[idx].iov_len = len;
	idx++;
	os_memset(&msg, 0, sizeof(msg));
	msg.msg_iov = io;
	msg.msg_iovlen = idx;

	dl_list_for_each_safe(dst, next, ctrl_dst, struct wpa_ctrl_dst, list) {
		int _errno;
		char txt[200];

		if (level < dst->debug_level)
			continue;

		msg.msg_name = (void *) &dst->addr;
		msg.msg_namelen = dst->addrlen;
		wpas_ctrl_sock_debug("ctrl_sock-sendmsg", sock, buf, len);
		if (sendmsg(sock, &msg, MSG_DONTWAIT) >= 0) {
			sockaddr_print(MSG_MSGDUMP,
				       "CTRL_IFACE monitor sent successfully to",
				       &dst->addr, dst->addrlen);
			dst->errors = 0;
			continue;
		}

		_errno = errno;
		os_snprintf(txt, sizeof(txt), "CTRL_IFACE monitor: %d (%s) for",
			    _errno, strerror(_errno));
		sockaddr_print(MSG_DEBUG, txt, &dst->addr, dst->addrlen);
		dst->errors++;

		if (dst->errors > 10 || _errno == ENOENT || _errno == EPERM) {
			sockaddr_print(MSG_INFO, "CTRL_IFACE: Detach monitor that cannot receive messages:",
				       &dst->addr, dst->addrlen);
			wpa_supplicant_ctrl_iface_detach(ctrl_dst, &dst->addr,
							 dst->addrlen);
		}

		if (_errno == ENOBUFS || _errno == EAGAIN) {
			/*
			 * The socket send buffer could be full. This may happen
			 * if client programs are not receiving their pending
			 * messages. Close and reopen the socket as a workaround
			 * to avoid getting stuck being unable to send any new
			 * responses.
			 */
			if (priv)
				sock = wpas_ctrl_iface_reinit(wpa_s, priv);
			else if (gp)
				sock = wpas_ctrl_iface_global_reinit(
					wpa_s->global, gp);
			else
				break;
			if (sock < 0) {
				wpa_dbg(wpa_s, MSG_DEBUG,
					"Failed to reinitialize ctrl_iface socket");
				break;
			}
		}
	}
}


void wpa_supplicant_ctrl_iface_wait(struct ctrl_iface_priv *priv)
{
	char buf[256];
	int res;
	struct sockaddr_storage from;
	socklen_t fromlen = sizeof(from);

	if (priv->sock == -1)
		return;

	for (;;) {
		wpa_printf(MSG_DEBUG, "CTRL_IFACE - %s - wait for monitor to "
			   "attach", priv->wpa_s->ifname);
		eloop_wait_for_read_sock(priv->sock);

		res = recvfrom(priv->sock, buf, sizeof(buf) - 1, 0,
			       (struct sockaddr *) &from, &fromlen);
		if (res < 0) {
			wpa_printf(MSG_ERROR, "recvfrom(ctrl_iface): %s",
				   strerror(errno));
			continue;
		}
		buf[res] = '\0';

		if (os_strcmp(buf, "ATTACH") == 0) {
			/* handle ATTACH signal of first monitor interface */
			if (!wpa_supplicant_ctrl_iface_attach(&priv->ctrl_dst,
							      &from, fromlen,
							      0)) {
				if (sendto(priv->sock, "OK\n", 3, 0,
					   (struct sockaddr *) &from, fromlen) <
				    0) {
					wpa_printf(MSG_DEBUG, "ctrl_iface sendto failed: %s",
						   strerror(errno));
				}
				/* OK to continue */
				return;
			} else {
				if (sendto(priv->sock, "FAIL\n", 5, 0,
					   (struct sockaddr *) &from, fromlen) <
				    0) {
					wpa_printf(MSG_DEBUG, "ctrl_iface sendto failed: %s",
						   strerror(errno));
				}
			}
		} else {
			/* return FAIL for all other signals */
			if (sendto(priv->sock, "FAIL\n", 5, 0,
				   (struct sockaddr *) &from, fromlen) < 0) {
				wpa_printf(MSG_DEBUG,
					   "ctrl_iface sendto failed: %s",
					   strerror(errno));
			}
		}
	}
}


/* Global ctrl_iface */

static void wpa_supplicant_global_ctrl_iface_receive(int sock, void *eloop_ctx,
						     void *sock_ctx)
{
	struct wpa_global *global = eloop_ctx;
	struct ctrl_iface_global_priv *priv = sock_ctx;
	char *buf;
	int res;
	struct sockaddr_storage from;
	socklen_t fromlen = sizeof(from);
	char *reply = NULL, *reply_buf = NULL;
	size_t reply_len;

	buf = os_malloc(CTRL_IFACE_MAX_LEN + 1);
	if (!buf)
		return;
	res = recvfrom(sock, buf, CTRL_IFACE_MAX_LEN + 1, 0,
		       (struct sockaddr *) &from, &fromlen);
	if (res < 0) {
		wpa_printf(MSG_ERROR, "recvfrom(ctrl_iface): %s",
			   strerror(errno));
		os_free(buf);
		return;
	}
	if ((size_t) res > CTRL_IFACE_MAX_LEN) {
		wpa_printf(MSG_ERROR, "recvform(ctrl_iface): input truncated");
		os_free(buf);
		return;
	}
	buf[res] = '\0';

	if (os_strcmp(buf, "ATTACH") == 0) {
		if (wpa_supplicant_ctrl_iface_attach(&priv->ctrl_dst, &from,
						     fromlen, 1))
			reply_len = 1;
		else
			reply_len = 2;
	} else if (os_strcmp(buf, "DETACH") == 0) {
		if (wpa_supplicant_ctrl_iface_detach(&priv->ctrl_dst, &from,
						     fromlen))
			reply_len = 1;
		else
			reply_len = 2;
	} else {
		reply_buf = wpa_supplicant_global_ctrl_iface_process(
			global, buf, &reply_len);
		reply = reply_buf;

		/*
		 * There could be some password/key material in the command, so
		 * clear the buffer explicitly now that it is not needed
		 * anymore.
		 */
		os_memset(buf, 0, res);
	}

	if (!reply && reply_len == 1) {
		reply = "FAIL\n";
		reply_len = 5;
	} else if (!reply && reply_len == 2) {
		reply = "OK\n";
		reply_len = 3;
	}

	if (reply) {
		wpas_ctrl_sock_debug("global_ctrl_sock-sendto",
				     sock, reply, reply_len);
		if (sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from,
			   fromlen) < 0) {
			wpa_printf(MSG_DEBUG, "ctrl_iface sendto failed: %s",
				strerror(errno));
		}
	}
	os_free(reply_buf);
	os_free(buf);
}


static int wpas_global_ctrl_iface_open_sock(struct wpa_global *global,
					    struct ctrl_iface_global_priv *priv)
{
	struct sockaddr_un addr;
	const char *ctrl = global->params.ctrl_interface;
	int flags;

	wpa_printf(MSG_DEBUG, "Global control interface '%s'", ctrl);

#ifdef ANDROID
	if (os_strncmp(ctrl, "@android:", 9) == 0) {
		priv->sock = android_get_control_socket(ctrl + 9);
		if (priv->sock < 0) {
			wpa_printf(MSG_ERROR, "Failed to open Android control "
				   "socket '%s'", ctrl + 9);
			goto fail;
		}
		wpa_printf(MSG_DEBUG, "Using Android control socket '%s'",
			   ctrl + 9);
		priv->android_control_socket = 1;
		goto havesock;
	}

	if (os_strncmp(ctrl, "@abstract:", 10) != 0) {
		/*
		 * Backwards compatibility - try to open an Android control
		 * socket and if that fails, assume this was a UNIX domain
		 * socket instead.
		 */
		priv->sock = android_get_control_socket(ctrl);
		if (priv->sock >= 0) {
			wpa_printf(MSG_DEBUG,
				   "Using Android control socket '%s'",
				   ctrl);
			priv->android_control_socket = 1;
			goto havesock;
		}
	}
#endif /* ANDROID */

	priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (priv->sock < 0) {
		wpa_printf(MSG_ERROR, "socket(PF_UNIX): %s", strerror(errno));
		goto fail;
	}

	os_memset(&addr, 0, sizeof(addr));
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	addr.sun_len = sizeof(addr);
#endif /* __FreeBSD__ */
	addr.sun_family = AF_UNIX;

	if (os_strncmp(ctrl, "@abstract:", 10) == 0) {
		addr.sun_path[0] = '\0';
		os_strlcpy(addr.sun_path + 1, ctrl + 10,
			   sizeof(addr.sun_path) - 1);
		if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) <
		    0) {
			wpa_printf(MSG_ERROR, "supp-global-ctrl-iface-init: "
				   "bind(PF_UNIX;%s) failed: %s",
				   ctrl, strerror(errno));
			goto fail;
		}
		wpa_printf(MSG_DEBUG, "Using Abstract control socket '%s'",
			   ctrl + 10);
		goto havesock;
	}

	os_strlcpy(addr.sun_path, ctrl, sizeof(addr.sun_path));
	if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
		wpa_printf(MSG_INFO, "supp-global-ctrl-iface-init(%s) (will try fixup): bind(PF_UNIX): %s",
			   ctrl, strerror(errno));
		if (connect(priv->sock, (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(ctrl) < 0) {
				wpa_printf(MSG_ERROR,
					   "Could not unlink existing ctrl_iface socket '%s': %s",
					   ctrl, strerror(errno));
				goto fail;
			}
			if (bind(priv->sock, (struct sockaddr *) &addr,
				 sizeof(addr)) < 0) {
				wpa_printf(MSG_ERROR, "supp-glb-iface-init: bind(PF_UNIX;%s): %s",
					   ctrl, strerror(errno));
				goto fail;
			}
			wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
				   "ctrl_iface socket '%s'",
				   ctrl);
		} 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",
				   ctrl);
			goto fail;
		}
	}

	wpa_printf(MSG_DEBUG, "Using UNIX control socket '%s'", ctrl);

	if (global->params.ctrl_interface_group) {
		char *gid_str = global->params.ctrl_interface_group;
		gid_t gid = 0;
		struct group *grp;
		char *endp;

		grp = getgrnam(gid_str);
		if (grp) {
			gid = grp->gr_gid;
			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d"
				   " (from group name '%s')",
				   (int) gid, gid_str);
		} else {
			/* Group name not found - try to parse this as gid */
			gid = strtol(gid_str, &endp, 10);
			if (*gid_str == '\0' || *endp != '\0') {
				wpa_printf(MSG_ERROR, "CTRL: Invalid group "
					   "'%s'", gid_str);
				goto fail;
			}
			wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d",
				   (int) gid);
		}
		if (lchown(ctrl, -1, gid) < 0) {
			wpa_printf(MSG_ERROR,
				   "lchown[global_ctrl_interface=%s,gid=%d]: %s",
				   ctrl, (int) gid, strerror(errno));
			goto fail;
		}

		if (chmod(ctrl, S_IRWXU | S_IRWXG) < 0) {
			wpa_printf(MSG_ERROR,
				   "chmod[global_ctrl_interface=%s]: %s",
				   ctrl, strerror(errno));
			goto fail;
		}
	} else {
		if (chmod(ctrl, S_IRWXU) < 0) {
			wpa_printf(MSG_DEBUG,
				   "chmod[global_ctrl_interface=%s](S_IRWXU): %s",
				   ctrl, strerror(errno));
			/* continue anyway since group change was not required
			 */
		}
	}

havesock:

	/*
	 * Make socket non-blocking so that we don't hang forever if
	 * target dies unexpectedly.
	 */
	flags = fcntl(priv->sock, F_GETFL);
	if (flags >= 0) {
		flags |= O_NONBLOCK;
		if (fcntl(priv->sock, F_SETFL, flags) < 0) {
			wpa_printf(MSG_INFO, "fcntl(ctrl, O_NONBLOCK): %s",
				   strerror(errno));
			/* Not fatal, continue on.*/
		}
	}

	eloop_register_read_sock(priv->sock,
				 wpa_supplicant_global_ctrl_iface_receive,
				 global, priv);

	return 0;

fail:
	if (priv->sock >= 0) {
		close(priv->sock);
		priv->sock = -1;
	}
	return -1;
}


struct ctrl_iface_global_priv *
wpa_supplicant_global_ctrl_iface_init(struct wpa_global *global)
{
	struct ctrl_iface_global_priv *priv;

	priv = os_zalloc(sizeof(*priv));
	if (priv == NULL)
		return NULL;
	dl_list_init(&priv->ctrl_dst);
	dl_list_init(&priv->msg_queue);
	priv->global = global;
	priv->sock = -1;

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

	if (wpas_global_ctrl_iface_open_sock(global, priv) < 0) {
		os_free(priv);
		return NULL;
	}

	wpa_msg_register_cb(wpa_supplicant_ctrl_iface_msg_cb);

	return priv;
}


static int wpas_ctrl_iface_global_reinit(struct wpa_global *global,
					 struct ctrl_iface_global_priv *priv)
{
	int res;

	if (priv->sock <= 0)
		return -1;

	/*
	 * On Android, the control socket being used may be the socket
	 * that is created when wpa_supplicant is started as a /init.*.rc
	 * service. Such a socket is maintained as a key-value pair in
	 * Android's environment. Closing this control socket would leave us
	 * in a bad state with an invalid socket descriptor.
	 */
	if (priv->android_control_socket)
		return priv->sock;

	eloop_unregister_read_sock(priv->sock);
	close(priv->sock);
	priv->sock = -1;
	res = wpas_global_ctrl_iface_open_sock(global, priv);
	if (res < 0)
		return -1;
	return priv->sock;
}


void
wpa_supplicant_global_ctrl_iface_deinit(struct ctrl_iface_global_priv *priv)
{
	struct wpa_ctrl_dst *dst, *prev;
	struct ctrl_iface_msg *msg, *prev_msg;

	if (priv->sock >= 0) {
		eloop_unregister_read_sock(priv->sock);
		close(priv->sock);
	}
	if (priv->global->params.ctrl_interface)
		unlink(priv->global->params.ctrl_interface);
	dl_list_for_each_safe(dst, prev, &priv->ctrl_dst, struct wpa_ctrl_dst,
			      list) {
		dl_list_del(&dst->list);
		os_free(dst);
	}
	dl_list_for_each_safe(msg, prev_msg, &priv->msg_queue,
			      struct ctrl_iface_msg, list) {
		dl_list_del(&msg->list);
		os_free(msg);
	}
	os_free(priv);
}