path: root/cacheserver/utmpserver.c

/* $Id$ */
#include "bbs.h"
#include <err.h>

struct {
    int     uid;
    int     nFriends, nRejects;
    int     friend[MAX_FRIEND];
    int     reject[MAX_REJECT];
} utmp[USHM_SIZE];

inline int countarray(int *s, int max)
{
    int     i;
    for( i = 0 ; i < max && s[i] ; ++i )
    ;
    return i;
}

int
reverse_friend_stat(int stat)
{
    int             stat1 = 0;
    if (stat & IFH)
        stat1 |= HFM;
    if (stat & IRH)
        stat1 |= HRM;
    if (stat & HFM)
        stat1 |= IFH;
    if (stat & HRM)
        stat1 |= IRH;
    if (stat & IBH)
        stat1 |= IBH;
    return stat1;
}

int set_friend_bit(int me, int ui)
{
    int     hit = 0;
    /* 判斷對方是否為我的朋友 ? */
    if( intbsearch(utmp[ui].uid, utmp[me].friend, utmp[me].nFriends) )
        hit = IFH;

    /* 判斷我是否為對方的朋友 ? */
    if( intbsearch(utmp[me].uid, utmp[ui].friend, utmp[ui].nFriends) )
        hit |= HFM;

    /* 判斷對方是否為我的仇人 ? */
    if( intbsearch(utmp[ui].uid, utmp[me].reject, utmp[me].nRejects) )
    hit |= IRH;

    /* 判斷我是否為對方的仇人 ? */
    if( intbsearch(utmp[me].uid, utmp[ui].reject, utmp[ui].nRejects) )
    hit |= HRM;

    return hit;
}

void initdata(int index)
{
    utmp[index].nFriends = countarray(utmp[index].friend, MAX_FRIEND);
    utmp[index].nRejects = countarray(utmp[index].reject, MAX_REJECT);
    if( utmp[index].nFriends > 0 )
    qsort(utmp[index].friend, utmp[index].nFriends,
          sizeof(int), qsort_intcompar);
    if( utmp[index].nRejects > 0 )
    qsort(utmp[index].reject, utmp[index].nRejects,
          sizeof(int), qsort_intcompar);
}

/* XXX 具有被 DoS 的可能, 請用 firewall 之類擋起來 */
int main(int argc, char **argv)
{
    struct  sockaddr_in     clientaddr;
    int     ch, port = 5120, sfd, cfd, len, index, i, uid;

    while( (ch = getopt(argc, argv, "p:h")) != -1 )
    switch( ch ){
    case 'p':
        port = atoi(optarg);
        break;

    case 'h':
    default:
        fprintf(stderr, "usage: utmpserver [-p port]\n");
        return 1;
    }

    if( (sfd = tobind(port)) < 0 )
    return 1;

    while( 1 ){
    len = sizeof(clientaddr);
    if( (cfd = accept(sfd, (struct sockaddr *)&clientaddr, &len)) < 0 ){
        if( errno != EINTR )
        sleep(1);
        continue;
    }
    toread(cfd, &index, sizeof(index));
    if( index == -1 ){
        int     nSynced = 0;
        for( i = 0 ; i < USHM_SIZE ; ++i, ++nSynced )
        if( toread(cfd, &utmp[i].uid, sizeof(utmp[i].uid)) > 0      &&
            toread(cfd, utmp[i].friend, sizeof(utmp[i].friend)) > 0 &&
            toread(cfd, utmp[i].reject, sizeof(utmp[i].reject)) > 0 ){
            if( utmp[i].uid )
            initdata(i);
        }
        else
            for( ; i < USHM_SIZE ; ++i )
            utmp[i].uid = 0;
        close(cfd);
        fprintf(stderr, "%d users synced\n", nSynced);
        continue;
    }

    if( toread(cfd, &uid, sizeof(uid)) > 0                              &&
        toread(cfd, utmp[index].friend, sizeof(utmp[index].friend)) > 0 &&
        toread(cfd, utmp[index].reject, sizeof(utmp[index].reject)) > 0 ){
#define MAX_FS   (2 * MAX_FRIEND)
        int     iu, nFrs, stat, rstat;
        ocfs_t  fs[MAX_FS];

        utmp[index].uid = uid;
        initdata(index);

        for( nFrs = iu = 0 ; iu < USHM_SIZE && nFrs < MAX_FS ; ++iu )
        if( iu != index && utmp[iu].uid ){
            if( (stat = set_friend_bit(index, iu)) ){
            rstat = reverse_friend_stat(stat);
            fs[nFrs].index = iu;
            fs[nFrs].uid = utmp[iu].uid;
            fs[nFrs].friendstat = (stat << 24) + iu;
            fs[nFrs].rfriendstat = (rstat << 24) + index;
            ++nFrs;
            }
        }

        towrite(cfd, &fs, sizeof(ocfs_t) * nFrs);
    }
    close(cfd);
    }
    return 0;
}