/*      $OpenBSD: iapp.c,v 1.20 2019/05/10 01:29:31 guenther Exp $      */

/*
 * Copyright (c) 2004, 2005 Reyk Floeter <reyk@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>

#include <net/if.h>
#include <net/if_media.h>
#include <net/if_arp.h>
#include <net/if_llc.h>
#include <net/bpf.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>

#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

#include "hostapd.h"
#include "iapp.h"

void
hostapd_iapp_init(struct hostapd_config *cfg)
{
        struct hostapd_apme *apme;
        struct hostapd_iapp *iapp = &cfg->c_iapp;

        if ((cfg->c_flags & HOSTAPD_CFG_F_APME) == 0)
                return;

        TAILQ_FOREACH(apme, &cfg->c_apmes, a_entries) {
                /* Get Host AP's BSSID */
                hostapd_priv_apme_bssid(apme);
                hostapd_log(HOSTAPD_LOG,
                    "%s/%s: attached Host AP interface with BSSID %s",
                    apme->a_iface, iapp->i_iface,
                    etheraddr_string(apme->a_bssid));

                /* Deauthenticate all stations on startup */
                (void)hostapd_apme_deauth(apme);
        }
}

void
hostapd_iapp_term(struct hostapd_config *cfg)
{
        struct hostapd_apme *apme;
        struct hostapd_iapp *iapp = &cfg->c_iapp;

        if ((cfg->c_flags & HOSTAPD_CFG_F_APME) == 0)
                return;

        TAILQ_FOREACH(apme, &cfg->c_apmes, a_entries) {
                hostapd_log(HOSTAPD_LOG_VERBOSE,
                    "%s/%s: detaching from Host AP",
                    apme->a_iface, iapp->i_iface);
        }
}

int
hostapd_iapp_add_notify(struct hostapd_apme *apme, struct hostapd_node *node)
{
        struct hostapd_config *cfg = (struct hostapd_config *)apme->a_cfg;
        struct hostapd_iapp *iapp = &cfg->c_iapp;
        struct sockaddr_in *addr;
        struct {
                struct ieee80211_iapp_frame hdr;
                struct ieee80211_iapp_add_notify add;
        } __packed frame;

        if ((iapp->i_flags & HOSTAPD_IAPP_F_ADD_NOTIFY) == 0)
                return (0);

        /*
         * Send an ADD.notify message to other access points to notify
         * about a new association on our Host AP.
         */
        bzero(&frame, sizeof(frame));

        frame.hdr.i_version = IEEE80211_IAPP_VERSION;
        frame.hdr.i_command = IEEE80211_IAPP_FRAME_ADD_NOTIFY;
        frame.hdr.i_identifier = htons(iapp->i_cnt++);
        frame.hdr.i_length = sizeof(struct ieee80211_iapp_add_notify);

        frame.add.a_length = IEEE80211_ADDR_LEN;
        frame.add.a_seqnum = htons(node->ni_rxseq);
        bcopy(node->ni_macaddr, frame.add.a_macaddr, IEEE80211_ADDR_LEN);

        if (cfg->c_flags & HOSTAPD_CFG_F_BRDCAST)
                addr = &iapp->i_broadcast;
        else
                addr = &iapp->i_multicast;

        if (sendto(iapp->i_udp, &frame, sizeof(frame),
            0, (struct sockaddr *)addr, sizeof(struct sockaddr_in)) == -1) {
                hostapd_log(HOSTAPD_LOG,
                    "%s: failed to send ADD notification: %s",
                    iapp->i_iface, strerror(errno));
                return (errno);
        }

        hostapd_log(HOSTAPD_LOG, "%s/%s: sent ADD notification for %s",
            apme->a_iface, iapp->i_iface,
            etheraddr_string(frame.add.a_macaddr));

        /* Send a LLC XID frame, see llc.c for details */
        return (hostapd_priv_llc_xid(cfg, node));
}

int
hostapd_iapp_radiotap(struct hostapd_apme *apme, u_int8_t *buf,
    const u_int len)
{
        struct hostapd_config *cfg = (struct hostapd_config *)apme->a_cfg;
        struct hostapd_iapp *iapp = &cfg->c_iapp;
        struct sockaddr_in *addr;
        struct ieee80211_iapp_frame hdr;
        struct msghdr msg;
        struct iovec iov[2];

        /*
         * Send an HOSTAPD.pcap/radiotap message to other access points
         * with an appended network dump. This is an hostapd extension to
         * IAPP.
         */
        bzero(&hdr, sizeof(hdr));

        hdr.i_version = IEEE80211_IAPP_VERSION;
        if (cfg->c_apme_dlt == DLT_IEEE802_11_RADIO)
                hdr.i_command = IEEE80211_IAPP_FRAME_HOSTAPD_RADIOTAP;
        else if (cfg->c_apme_dlt == DLT_IEEE802_11)
                hdr.i_command = IEEE80211_IAPP_FRAME_HOSTAPD_PCAP;
        else
                return (EINVAL);
        hdr.i_identifier = htons(iapp->i_cnt++);
        hdr.i_length = len;

        if (cfg->c_flags & HOSTAPD_CFG_F_BRDCAST)
                addr = &iapp->i_broadcast;
        else
                addr = &iapp->i_multicast;

        iov[0].iov_base = &hdr;
        iov[0].iov_len = sizeof(hdr);
        iov[1].iov_base = buf;
        iov[1].iov_len = len;
        msg.msg_name = (caddr_t)addr;
        msg.msg_namelen = sizeof(struct sockaddr_in);
        msg.msg_iov = iov;
        msg.msg_iovlen = 2;
        msg.msg_control = 0;
        msg.msg_controllen = 0;
        msg.msg_flags = 0;

        if (sendmsg(iapp->i_udp, &msg, 0) == -1) {
                hostapd_log(HOSTAPD_LOG,
                    "%s: failed to send HOSTAPD %s: %s",
                    iapp->i_iface, cfg->c_apme_dlt ==
                    DLT_IEEE802_11_RADIO ? "radiotap" : "pcap",
                    strerror(errno));
                return (errno);
        }

        return (0);
}

void
hostapd_iapp_input(int fd, short sig, void *arg)
{
        struct hostapd_config *cfg = (struct hostapd_config *)arg;
        struct hostapd_iapp *iapp = &cfg->c_iapp;
        struct hostapd_apme *apme;
        struct sockaddr_in addr;
        socklen_t addr_len;
        ssize_t len;
        u_int8_t buf[IAPP_MAXSIZE];
        struct hostapd_node node;
        struct ieee80211_iapp_recv {
                struct ieee80211_iapp_frame hdr;
                union {
                        struct ieee80211_iapp_add_notify add;
                        u_int8_t buf[1];
                } u;
        } __packed *frame;
        u_int dlt;
        int ret = 0;

        /* Ignore invalid signals */
        if (sig != EV_READ)
                return;

        /*
         * Listen to possible messages from other IAPP
         */
        bzero(buf, sizeof(buf));

        if ((len = recvfrom(fd, buf, sizeof(buf), 0,
            (struct sockaddr*)&addr, &addr_len)) < 1)
                return;

        if (bcmp(&iapp->i_addr.sin_addr, &addr.sin_addr,
            sizeof(addr.sin_addr)) == 0)
                return;

        frame = (struct ieee80211_iapp_recv*)buf;

        /* Validate the IAPP version */
        if (len < (ssize_t)sizeof(struct ieee80211_iapp_frame) ||
            frame->hdr.i_version != IEEE80211_IAPP_VERSION ||
            addr_len < sizeof(struct sockaddr_in))
                return;

        cfg->c_stats.cn_rx_iapp++;

        /*
         * Process the IAPP frame
         */
        switch (frame->hdr.i_command) {
        case IEEE80211_IAPP_FRAME_ADD_NOTIFY:
                /* Short frame */
                if (len < (ssize_t)(sizeof(struct ieee80211_iapp_frame) +
                    sizeof(struct ieee80211_iapp_add_notify)))
                        return;

                /* Don't support non-48bit MAC addresses, yet */
                if (frame->u.add.a_length != IEEE80211_ADDR_LEN)
                        return;

                node.ni_rxseq = frame->u.add.a_seqnum;
                bcopy(frame->u.add.a_macaddr, node.ni_macaddr,
                    IEEE80211_ADDR_LEN);

                /*
                 * Try to remove a node from our Host AP and to free
                 * any allocated resources. Otherwise the received
                 * ADD.notify message will be ignored.
                 */
                if (iapp->i_flags & HOSTAPD_IAPP_F_ADD &&
                    cfg->c_flags & HOSTAPD_CFG_F_APME) {
                        TAILQ_FOREACH(apme, &cfg->c_apmes, a_entries) {
                                if (iapp->i_flags & HOSTAPD_IAPP_F_ROAMING)
                                        (void)hostapd_roaming_del(apme, &node);
                                if (iapp->i_flags & HOSTAPD_IAPP_F_ADD_NOTIFY &&
                                    (ret = hostapd_apme_delnode(apme,
                                    &node)) == 0)
                                        cfg->c_stats.cn_tx_apme++;
                        }
                } else
                        ret = 0;

                hostapd_log(iapp->i_flags & HOSTAPD_IAPP_F_ADD ?
                    HOSTAPD_LOG : HOSTAPD_LOG_VERBOSE,
                    "%s: %s ADD notification for %s at %s",
                    iapp->i_iface, ret == 0 ?
                    "received" : "ignored",
                    etheraddr_string(node.ni_macaddr),
                    inet_ntoa(addr.sin_addr));
                break;

        case IEEE80211_IAPP_FRAME_HOSTAPD_PCAP:
        case IEEE80211_IAPP_FRAME_HOSTAPD_RADIOTAP:
                if ((iapp->i_flags & HOSTAPD_IAPP_F_RADIOTAP) == 0)
                        return;

                /* Short frame */
                if (len <= (ssize_t)sizeof(struct ieee80211_iapp_frame) ||
                    frame->hdr.i_length < sizeof(struct ieee80211_frame))
                        return;

                dlt = frame->hdr.i_command ==
                    IEEE80211_IAPP_FRAME_HOSTAPD_PCAP ?
                    DLT_IEEE802_11 : DLT_IEEE802_11_RADIO;

                hostapd_print_ieee80211(dlt, 1, (u_int8_t *)frame->u.buf,
                    len - sizeof(struct ieee80211_iapp_frame));
                return;

        case IEEE80211_IAPP_FRAME_MOVE_NOTIFY:
        case IEEE80211_IAPP_FRAME_MOVE_RESPONSE:
        case IEEE80211_IAPP_FRAME_SEND_SECURITY_BLOCK:
        case IEEE80211_IAPP_FRAME_ACK_SECURITY_BLOCK:
        case IEEE80211_IAPP_FRAME_CACHE_NOTIFY:
        case IEEE80211_IAPP_FRAME_CACHE_RESPONSE:

                /*
                 * XXX TODO
                 */

                hostapd_log(HOSTAPD_LOG_VERBOSE,
                    "%s: received unsupported IAPP message %d",
                    iapp->i_iface, frame->hdr.i_command);
                return;

        default:
                return;
        }
}