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
29 #include <netdb.h>
30
31 #include <endian.h>
32 #include <stdlib.h>
33 #include <string.h>
34
35 #include "resolv_static.h"
36 #include "services.h"
37
getservent_r(struct res_static * rs)38 struct servent* getservent_r(struct res_static* rs) {
39 const char* p;
40 const char* q;
41 int namelen;
42 int nn,count;
43 int total = 0;
44 int port;
45 char* p2;
46
47 p = rs->servent_ptr;
48 if (p == NULL)
49 p = _services;
50 else if (p[0] == 0)
51 return NULL;
52
53 /* first compute the total size */
54 namelen = p[0];
55 total += namelen + 1;
56 q = p + 1 + namelen + 3; /* skip name + port + proto */
57 count = q[0]; /* get aliascount */
58 q += 1;
59
60 total += (count+1)*sizeof(char*);
61 for (nn = 0; nn < count; nn++) {
62 int len2 = q[0];
63 total += 1 + len2;
64 q += 1 + len2;
65 }
66
67 /* reallocate the thread-specific servent struct */
68 p2 = realloc( (char*)rs->servent.s_aliases, total );
69 if (p2 == NULL)
70 return NULL;
71
72 /* now write to it */
73 rs->servent.s_aliases = (char**) p2;
74 p2 += (count+1)*sizeof(char*);
75 rs->servent.s_name = p2;
76 p2 += namelen + 1;
77 rs->servent.s_proto = p2;
78
79 /* copy name + port + setup protocol */
80 memcpy( rs->servent.s_name, p+1, namelen );
81 rs->servent.s_name[namelen] = 0;
82 p += 1 + namelen;
83
84 /* s_port must be in network byte order */
85 port = ((((unsigned char*)p)[0] << 8) |
86 ((unsigned char*)p)[1]);
87
88 rs->servent.s_port = htons(port);
89 rs->servent.s_proto = p[2] == 't' ? "tcp" : "udp";
90 p += 4; /* skip port(2) + proto(1) + aliascount(1) */
91
92 for (nn = 0; nn < count; nn++) {
93 int len2 = p[0];
94 rs->servent.s_aliases[nn] = p2;
95 memcpy( p2, p+1, len2 );
96 p2[len2] = 0;
97 p2 += len2 + 1;
98 p += len2 + 1;
99 }
100 rs->servent.s_aliases[nn] = NULL;
101
102 rs->servent_ptr = p;
103
104 return &rs->servent;
105 }
106
setservent(int stayopen)107 void setservent(int stayopen) {
108 endservent();
109 }
110
endservent(void)111 void endservent(void) {
112 struct res_static* rs = __res_get_static();
113 if (rs) rs->servent_ptr = NULL;
114 }
115
getservent(void)116 struct servent* getservent(void) {
117 struct res_static* rs = __res_get_static();
118 return rs ? getservent_r(rs) : NULL;
119 }
120
getservbyname(const char * name,const char * proto)121 struct servent* getservbyname(const char* name, const char* proto) {
122 struct res_static* rs = __res_get_static();
123 if (rs == NULL) return NULL;
124
125 const char* old_servent_ptr = rs->servent_ptr;
126 rs->servent_ptr = NULL;
127 struct servent* s;
128 while ((s = getservent_r(rs)) != NULL) {
129 if (strcmp(s->s_name, name) == 0 && (proto == NULL || strcmp(s->s_proto, proto) == 0)) {
130 break;
131 }
132 }
133 rs->servent_ptr = old_servent_ptr;
134 return s;
135 }
136
getservbyport(int port,const char * proto)137 struct servent* getservbyport(int port, const char* proto) {
138 struct res_static* rs = __res_get_static();
139 if (rs == NULL) return NULL;
140
141 const char* old_servent_ptr = rs->servent_ptr;
142 rs->servent_ptr = NULL;
143 struct servent* s;
144 while ((s = getservent_r(rs)) != NULL) {
145 if (s->s_port == port && (proto == NULL || strcmp(s->s_proto, proto) == 0)) {
146 break;
147 }
148 }
149 rs->servent_ptr = old_servent_ptr;
150 return s;
151 }
152