#include <sys/types.h>
#include <sys/socket.h>
#include <linux/types.h> 
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/if.h>
#include <assert.h>
#include <libdaemon/dlog.h>
#include "wireless.h"

#include "util.h"
#include "assocwatch.h"
#include "nlapi.h"

static int handle_wireless_event(int idx, uint8_t *data, int l, int (*cb) (int idx, struct hw_addr *a)) {
    struct iw_event *e;
    int hs;
    struct hw_addr ap;

    e = (struct iw_event*) data;
    hs = sizeof(struct iw_event)-sizeof(union iwreq_data);
    while (l >= sizeof(struct iw_event)) {
        
        if (e->len < hs) {
            daemon_log(LOG_ERR, "ASSOCWATCH: Recieved corrupt wireless event\n");
            return -1;
        }
        
        switch (e->cmd) {
            
            case SIOCGIWAP: 
                if (e->len < hs + sizeof(struct sockaddr)) {
                    daemon_log(LOG_ERR, "ASSOCWATCH: Recieved corrupt AP wireless event\n");
                    return -1;
                }

                memcpy(ap.addr, e->u.ap_addr.sa_data, ETH_ALEN);

                if (cb(idx, is_assoc_ap(&ap) ? &ap : NULL) < 0)
                    return -1;

                return 0;
        }

        l -= e->len;
        e = (struct iw_event*) (((uint8_t*) e) + e->len);
    }
    
    return 0;
}

static int callback(struct nlmsghdr *n, void *u) {
    int (*cb) (int idx, struct hw_addr *a) = u;
    
    if (n->nlmsg_type == RTM_NEWLINK) {
        struct ifinfomsg* ifi;
        struct rtattr *a;
        int la;
        
        if (n->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) {
            daemon_log(LOG_ERR, "ASSOCWATCH: Corrupt NETLINK message\n");
            return -1;
        }
        
        ifi = NLMSG_DATA(n);
        a = (void*) ifi + NLMSG_ALIGN(sizeof(struct ifinfomsg));
        la = NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg));
            
        while (RTA_OK(a, la)) {
            if(a->rta_type == IFLA_WIRELESS)
                handle_wireless_event(ifi->ifi_index, RTA_DATA(a), RTA_PAYLOAD(a), cb);
            
            a = RTA_NEXT(a, la);
        }
    }

    return 0;
}


int assocwatch_init(int (*cb) (int idx, struct hw_addr *a)) {
    return nlapi_register(callback, cb);
}