getservent.c revision 1dc9e472e19acfe6dc7f41e429236e7eef7ceda1 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28#include <sys/cdefs.h>
29#include <sys/types.h>
30#include <netdb.h>
31#include "servent.h"
32#include "services.h"
33
34void
35setservent(int f)
36{
37    res_static  rs = __res_get_static();
38    if (rs) {
39        rs->servent_ptr = NULL;
40    }
41}
42
43void
44endservent(void)
45{
46    /* nothing to do */
47}
48
49struct servent *
50getservent_r( res_static  rs )
51{
52    const char*  p;
53    const char*  q;
54    int          namelen;
55    int          nn,count;
56    int          total = 0;
57    char*        p2;
58
59    p = rs->servent_ptr;
60    if (p == NULL)
61        p = _services;
62    else if (p[0] == 0)
63        return NULL;
64
65    /* first compute the total size */
66    namelen = p[0];
67    total  += namelen + 1;
68    q       = p + 1 + namelen + 3;  /* skip name + port + proto */
69    count   = q[0];   /* get aliascount */
70    q      += 1;
71
72    total += (count+1)*sizeof(char*);
73    for (nn = 0; nn < count; nn++) {
74        int  len2 = q[0];
75        total += 1 + len2;
76        q     += 1 + len2;
77    }
78
79    /* reallocate the thread-specific servent struct */
80    p2 = realloc( (char*)rs->servent.s_aliases, total );
81    if (p2 == NULL)
82        return NULL;
83
84    /* now write to it */
85    rs->servent.s_aliases = (char**) p2;
86    p2                   += (count+1)*sizeof(char*);
87    rs->servent.s_name    = p2;
88    p2                   += namelen + 1;
89    rs->servent.s_proto   = p2;
90
91    /* copy name + port + setup protocol */
92    memcpy( rs->servent.s_name, p+1, namelen );
93    rs->servent.s_name[namelen] = 0;
94    p += 1 + namelen;
95    rs->servent.s_port = ((((unsigned char*)p)[0] << 8) |
96                           ((unsigned char*)p)[1]);
97
98    rs->servent.s_proto = p[2] == 't' ? "tcp" : "udp";
99    p += 4;  /* skip port(2) + proto(1) + aliascount(1) */
100
101    for (nn = 0; nn < count; nn++) {
102        int  len2 = p[0];
103        rs->servent.s_aliases[nn] = p2;
104        memcpy( p2, p+1, len2 );
105        p2[len2] = 0;
106        p2 += len2 + 1;
107        p  += len2 + 1;
108    }
109    rs->servent.s_aliases[nn] = NULL;
110
111    rs->servent_ptr = p;
112
113    return &rs->servent;
114}
115
116struct servent *
117getservent(void)
118{
119    res_static   rs = __res_get_static();
120
121    if (rs == NULL) return NULL;
122
123    return getservent_r(rs);
124}
125