summaryrefslogtreecommitdiffstats
path: root/cacheserver/utmpserver.c
blob: 05a5ccfd6ce0ccac620f3b259f49cd40d40498a5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
/* $Id$ */
#include "bbs.h"
#include <err.h>

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

#ifdef NOFLOODING
#define MAXWAIT 1024
#define FLUSHTIME (3600*6)

struct {
    time_t  lasttime;
    int     count;
} flooding[MAX_USERS];

int nWaits, lastflushtime;
struct {
    int     uid;
    int     fd;
    int     index;
} waitqueue[MAXWAIT];
#endif /* NOFLOODING */

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);
}

inline void syncutmp(int cfd)
{
    int     nSynced = 0, i;
    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);
}

void processlogin(int cfd, int uid, int index)
{
    if( toread(cfd, utmp[index].friend, sizeof(utmp[index].friend)) > 0 &&
    toread(cfd, utmp[index].reject, sizeof(utmp[index].reject)) > 0 ){
    /* 因為 logout 的時候並不會通知 utmpserver , 可能會查到一些
       已經 logout 的帳號。所以不能只取 MAX_FRIEND 而要多取一些 */
#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);
}

#ifdef NOFLOODING
void flushwaitqueue(void)
{
    int     i;
    for( i = 0 ; i < nWaits ; ++i )
    processlogin(waitqueue[i].fd, waitqueue[i].uid, waitqueue[i].index);
    lastflushtime = time(NULL);
    nWaits = 0;
    memset(flooding, 0, sizeof(flooding));
}
#endif

/* 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, uid;
    char   *iface_ip = NULL;

    while( (ch = getopt(argc, argv, "p:i:h")) != -1 )
    switch( ch ){
    case 'p':
        port = atoi(optarg);
        break;
    case 'i':
        iface_ip = optarg;
        break;
    case 'h':
    default:
        fprintf(stderr, "usage: utmpserver [-i interface_ip] [-p port]\n");
        return 1;
    }

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

#ifdef NOFLOODING
    lastflushtime = time(NULL);
#endif
    while( 1 ){
#ifdef NOFLOODING
    if( lastflushtime < (time(NULL) - 1800) )
        flushwaitqueue();
#endif

    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 ){
        syncutmp(cfd);
        continue;
    }

    if( toread(cfd, &uid, sizeof(uid)) > 0 ){
        if( !(0 < uid || uid > MAX_USERS) ){ /* for safety */
        close(cfd);
        continue;
        }

#ifdef NOFLOODING
        if( (time(NULL) - flooding[uid].lasttime) < 20 )
        ++flooding[uid].count;
        if( flooding[uid].count > 10 ){
        if( nWaits == MAXWAIT )
            flushwaitqueue();
        waitqueue[nWaits].uid = uid;
        waitqueue[nWaits].index = index;
        waitqueue[nWaits].fd = cfd;
        ++nWaits;

        continue;
        }
        flooding[uid].lasttime = time(NULL);
#endif

        /* cfd will be closed in processlogin() */
        processlogin(cfd, uid, index);
    }
    }
    return 0;
}