acl.c 8.73 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
/*****************************************************************************
 * acl.c:
 *****************************************************************************
 * Copyright (C) 2005 Rémi Denis-Courmont
 * $Id$
 *
 * Authors: Rémi Denis-Courmont <rem # videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
dionoea's avatar
dionoea committed
21
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22
23
24
25
26
27
28
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdlib.h>
#include <string.h>
29
#include <ctype.h>
30
31
32
33
#include <vlc/vlc.h>

#include "vlc_acl.h"

34
35
#include <errno.h>

36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
#include "network.h"

/* FIXME: rwlock on acl, but libvlc doesn't implement rwlock */
typedef struct vlc_acl_entry_t
{
    uint8_t    host[17];
    uint8_t    i_bytes_match;
    uint8_t    i_bits_mask;
    vlc_bool_t b_allow;
} vlc_acl_entry_t;

struct vlc_acl_t
{
    vlc_object_t    *p_owner;
    unsigned         i_size;
    vlc_acl_entry_t *p_entries;
    vlc_bool_t       b_allow_default;
};

static int ACL_Resolve( vlc_object_t *p_this, uint8_t *p_bytes,
                        const char *psz_ip )
{
58
    struct addrinfo hints = { 0 }, *res;
59
60
61
62
63
64
65
66
67
68
    int i_family;

    hints.ai_socktype = SOCK_STREAM; /* doesn't matter */
    hints.ai_flags = AI_NUMERICHOST;

    if( vlc_getaddrinfo( p_this, psz_ip, 0, &hints, &res ) )
    {
        msg_Err( p_this, "invalid IP address %s", psz_ip );
        return -1;
    }
69

70
71
72
73
74
75
76
77
    p_bytes[16] = 0; /* avoids overflowing when i_bytes_match = 16 */

    i_family = res->ai_addr->sa_family;
    switch( i_family )
    {
        case AF_INET:
        {
            struct sockaddr_in *addr;
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
            addr = (struct sockaddr_in *)res->ai_addr;
            memset( p_bytes, 0, 12 );
            memcpy( p_bytes + 12, &addr->sin_addr, 4 );
            break;
        }

#if defined (HAVE_GETADDRINFO) || defined (WIN32)
        /* unfortunately many people define AF_INET6
           though they don't have struct sockaddr_in6 */
        case AF_INET6:
        {
            struct sockaddr_in6 *addr;

            addr = (struct sockaddr_in6 *)res->ai_addr;
            memcpy( p_bytes, &addr->sin6_addr, 16 );
            break;
        }
#endif

        default:
            msg_Err( p_this, "IMPOSSIBLE: unknown address family!" );
            vlc_freeaddrinfo( res );
            return -1;
    }

    vlc_freeaddrinfo( res );
    return i_family;
}


/*
 * Returns 0 if allowed, 1 if not, -1 on error.
 */
int ACL_Check( vlc_acl_t *p_acl, const char *psz_ip )
{
    const vlc_acl_entry_t *p_cur, *p_end;
    uint8_t host[17];

    if( p_acl == NULL )
        return -1;

    p_cur = p_acl->p_entries;
    p_end = p_cur + p_acl->i_size;

    if( ACL_Resolve( p_acl->p_owner, host, psz_ip ) < 0 )
        return -1;

    while (p_cur < p_end)
    {
        unsigned i;

        i = p_cur->i_bytes_match;
        if( (memcmp( p_cur->host, host, i ) == 0)
         && (((p_cur->host[i] ^ host[i]) & p_cur->i_bits_mask) == 0) )
            return !p_cur->b_allow;

        p_cur++;
    }

    return !p_acl->b_allow_default;
}

int ACL_AddNet( vlc_acl_t *p_acl, const char *psz_ip, int i_len,
                vlc_bool_t b_allow )
{
    vlc_acl_entry_t *p_ent;
    unsigned i_size;
    div_t d;
    int i_family;

    i_size = p_acl->i_size;
    p_ent = (vlc_acl_entry_t *)realloc( p_acl->p_entries,
                                        ++p_acl->i_size * sizeof( *p_ent ) );

    if( p_ent == NULL )
        return -1;

156
157
158
    p_acl->p_entries = p_ent;
    p_ent += i_size;

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
    i_family = ACL_Resolve( p_acl->p_owner, p_ent->host, psz_ip );
    if( i_family < 0 )
    {
        /*
         * I'm lazy : memory space will be re-used in the next ACL_Add call...
         * or not.
         */
        p_acl->i_size--;
        return -1;
    }

    if( i_len >= 0 )
    {
        if( i_family == AF_INET )
            i_len += 96;

        if( i_len > 128 )
            i_len = 128;
        else
        if( i_len < 0 )
            i_len = 0;
    }
    else
        i_len = 128; /* ACL_AddHost */

    d = div( i_len, 8 );
    p_ent->i_bytes_match = d.quot;
    p_ent->i_bits_mask = 0xff << (8 - d.rem);

    p_ent->b_allow = b_allow;
    return 0;
}


vlc_acl_t *__ACL_Create( vlc_object_t *p_this, vlc_bool_t b_allow )
{
    vlc_acl_t *p_acl;

    p_acl = (vlc_acl_t *)malloc( sizeof( *p_acl ) );
    if( p_acl == NULL )
        return NULL;

    vlc_object_yield( p_this );
    p_acl->p_owner = p_this;
    p_acl->i_size = 0;
    p_acl->p_entries = NULL;
    p_acl->b_allow_default = b_allow;
206

207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
    return p_acl;
}


vlc_acl_t *__ACL_Duplicate( vlc_object_t *p_this, const vlc_acl_t *p_acl )
{
    vlc_acl_t *p_dupacl;

    if( p_acl == NULL )
        return NULL;

    p_dupacl = (vlc_acl_t *)malloc( sizeof( *p_dupacl ) );
    if( p_dupacl == NULL )
        return NULL;

222
    if( p_acl->i_size )
223
    {
224
225
226
227
228
229
230
231
232
233
234
235
236
237
        p_dupacl->p_entries = (vlc_acl_entry_t *)
            malloc( p_acl->i_size * sizeof( vlc_acl_entry_t ) );

        if( p_dupacl->p_entries == NULL )
        {
            free( p_dupacl );
            return NULL;
        }

        memcpy( p_dupacl->p_entries, p_acl->p_entries,
                p_acl->i_size * sizeof( vlc_acl_entry_t ) );
    }
    else
        p_dupacl->p_entries = NULL;
238
239
240
241

    vlc_object_yield( p_this );
    p_dupacl->p_owner = p_this;
    p_dupacl->i_size = p_acl->i_size;
242
243
    p_dupacl->b_allow_default = p_acl->b_allow_default;

244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
    return p_dupacl;
}


void ACL_Destroy( vlc_acl_t *p_acl )
{
    if( p_acl != NULL )
    {
        if( p_acl->p_entries != NULL )
            free( p_acl->p_entries );

        vlc_object_release( p_acl->p_owner );
        free( p_acl );
    }
}

260
261
262
#ifndef isblank 
#   define isblank(c) ((c) == ' ' || (c) == '\t')
#endif
263
264
265
266

int ACL_LoadFile( vlc_acl_t *p_acl, const char *psz_path )
{
    FILE *file;
267

268
269
270
271
272
273
274
275
276
277
278
279
280
    if( p_acl == NULL )
        return -1;

    file = fopen( psz_path, "r" );
    if( file == NULL )
        return -1;

    msg_Dbg( p_acl->p_owner, "find .hosts in dir=%s", psz_path );

    while( !feof( file ) )
    {
        char line[1024], *psz_ip, *ptr;

Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
281
        if( fgets( line, sizeof( line ), file ) == NULL )
282
283
284
285
286
287
288
289
290
291
        {
            if( ferror( file ) )
            {
                msg_Err( p_acl->p_owner, "Error reading %s : %s\n", psz_path,
                        strerror( errno ) );
                goto error;
            }
            continue;
        }

Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
292
        /* fgets() is cool : never overflow, always nul-terminate */
293
294
        psz_ip = line;

Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
295
        /* skips blanks - cannot overflow given '\0' is not space */
296
        while( isspace( *psz_ip ) )
297
298
            psz_ip++;

299
300
301
        if( *psz_ip == '\0' ) /* empty/blank line */
            continue;

302
303
304
305
306
307
308
        ptr = strchr( psz_ip, '\n' );
        if( ptr == NULL )
        {
            msg_Warn( p_acl->p_owner, "Skipping overly long line in %s\n",
                      psz_path);
            do
            {
Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
309
                fgets( line, sizeof( line ), file );
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
                if( ferror( file ) || feof( file ) )
                {
                    msg_Err( p_acl->p_owner, "Error reading %s : %s\n",
                             psz_path, strerror( errno ) );
                    goto error;
                }
            }
            while( strchr( line, '\n' ) == NULL);

            continue; /* skip unusable line */
        }

        /* skips comment-only line */
        if( *psz_ip == '#' )
            continue;

        /* looks for first space, CR, LF, etc. or end-of-line comment */
        /* (there is at least a linefeed) */
        for( ptr = psz_ip; ( *ptr != '#' ) && !isspace( *ptr ); ptr++ );

        *ptr = '\0';

        msg_Dbg( p_acl->p_owner, "restricted to %s", psz_ip );

        ptr = strchr( psz_ip, '/' );
        if( ptr != NULL )
            *ptr++ = '\0'; /* separate address from mask length */

        if( (ptr != NULL)
            ? ACL_AddNet( p_acl, psz_ip, atoi( ptr ), VLC_TRUE ) 
            : ACL_AddHost( p_acl, psz_ip, VLC_TRUE ) )
        {
            msg_Err( p_acl->p_owner, "cannot add ACL from %s", psz_path );
            goto error;
        }
    }

    fclose( file );
    return 0;

error:
    fclose( file );
    return -1;
}