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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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 are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/Assertions.h>
28#include <AK/ScopeGuard.h>
29#include <AK/String.h>
30#include <Kernel/Net/IPv4.h>
31#include <arpa/inet.h>
32#include <netdb.h>
33#include <netinet/in.h>
34#include <stdio.h>
35#include <string.h>
36#include <unistd.h>
37
38extern "C" {
39
40int h_errno;
41
42static hostent __gethostbyname_buffer;
43static char __gethostbyname_name_buffer[512];
44static in_addr_t __gethostbyname_address;
45static in_addr_t* __gethostbyname_address_list_buffer[2];
46
47static hostent __gethostbyaddr_buffer;
48static char __gethostbyaddr_name_buffer[512];
49static in_addr_t* __gethostbyaddr_address_list_buffer[2];
50
51static int connect_to_lookup_server()
52{
53 int fd = socket(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
54 if (fd < 0) {
55 perror("socket");
56 return -1;
57 }
58
59 sockaddr_un address;
60 address.sun_family = AF_LOCAL;
61 strcpy(address.sun_path, "/tmp/portal/lookup");
62
63 if (connect(fd, (const sockaddr*)&address, sizeof(address)) < 0) {
64 perror("connect_to_lookup_server");
65 close(fd);
66 return -1;
67 }
68 return fd;
69}
70
71hostent* gethostbyname(const char* name)
72{
73 auto ipv4_address = IPv4Address::from_string(name);
74 if (ipv4_address.has_value()) {
75 sprintf(__gethostbyname_name_buffer, "%s", ipv4_address.value().to_string().characters());
76 __gethostbyname_buffer.h_name = __gethostbyname_name_buffer;
77 __gethostbyname_buffer.h_aliases = nullptr;
78 __gethostbyname_buffer.h_addrtype = AF_INET;
79 new (&__gethostbyname_address) IPv4Address(ipv4_address.value());
80 __gethostbyname_address_list_buffer[0] = &__gethostbyname_address;
81 __gethostbyname_address_list_buffer[1] = nullptr;
82 __gethostbyname_buffer.h_addr_list = (char**)__gethostbyname_address_list_buffer;
83 __gethostbyname_buffer.h_length = 4;
84
85 return &__gethostbyname_buffer;
86 }
87
88 int fd = connect_to_lookup_server();
89 if (fd < 0)
90 return nullptr;
91
92 auto close_fd_on_exit = ScopeGuard([fd] {
93 close(fd);
94 });
95
96 auto line = String::format("L%s\n", name);
97 int nsent = write(fd, line.characters(), line.length());
98 if (nsent < 0) {
99 perror("write");
100 return nullptr;
101 }
102
103 ASSERT((size_t)nsent == line.length());
104
105 char buffer[1024];
106 int nrecv = read(fd, buffer, sizeof(buffer) - 1);
107 if (nrecv < 0) {
108 perror("recv");
109 return nullptr;
110 }
111
112 if (!memcmp(buffer, "Not found.", sizeof("Not found.") - 1))
113 return nullptr;
114
115 auto responses = String(buffer, nrecv).split('\n');
116 if (responses.is_empty())
117 return nullptr;
118
119 auto& response = responses[0];
120
121 int rc = inet_pton(AF_INET, response.characters(), &__gethostbyname_address);
122 if (rc <= 0)
123 return nullptr;
124
125 strncpy(__gethostbyname_name_buffer, name, strlen(name));
126
127 __gethostbyname_buffer.h_name = __gethostbyname_name_buffer;
128 __gethostbyname_buffer.h_aliases = nullptr;
129 __gethostbyname_buffer.h_addrtype = AF_INET;
130 __gethostbyname_address_list_buffer[0] = &__gethostbyname_address;
131 __gethostbyname_address_list_buffer[1] = nullptr;
132 __gethostbyname_buffer.h_addr_list = (char**)__gethostbyname_address_list_buffer;
133 __gethostbyname_buffer.h_length = 4;
134
135 return &__gethostbyname_buffer;
136}
137
138hostent* gethostbyaddr(const void* addr, socklen_t addr_size, int type)
139{
140 if (type != AF_INET) {
141 errno = EAFNOSUPPORT;
142 return nullptr;
143 }
144
145 if (addr_size < sizeof(in_addr)) {
146 errno = EINVAL;
147 return nullptr;
148 }
149
150 int fd = connect_to_lookup_server();
151 if (fd < 0)
152 return nullptr;
153
154 auto close_fd_on_exit = ScopeGuard([fd] {
155 close(fd);
156 });
157
158 IPv4Address ipv4_address((const u8*)&((const in_addr*)addr)->s_addr);
159
160 auto line = String::format("R%d.%d.%d.%d.in-addr.arpa\n",
161 ipv4_address[3],
162 ipv4_address[2],
163 ipv4_address[1],
164 ipv4_address[0]);
165 int nsent = write(fd, line.characters(), line.length());
166 if (nsent < 0) {
167 perror("write");
168 return nullptr;
169 }
170
171 ASSERT((size_t)nsent == line.length());
172
173 char buffer[1024];
174 int nrecv = read(fd, buffer, sizeof(buffer) - 1);
175 if (nrecv < 0) {
176 perror("recv");
177 return nullptr;
178 }
179
180 if (!memcmp(buffer, "Not found.", sizeof("Not found.") - 1))
181 return nullptr;
182
183 auto responses = String(buffer, nrecv).split('\n');
184 if (responses.is_empty())
185 return nullptr;
186
187 auto& response = responses[0];
188
189 strncpy(__gethostbyaddr_name_buffer, response.characters(), max(sizeof(__gethostbyaddr_name_buffer), response.length()));
190
191 __gethostbyaddr_buffer.h_name = __gethostbyaddr_name_buffer;
192 __gethostbyaddr_buffer.h_aliases = nullptr;
193 __gethostbyaddr_buffer.h_addrtype = AF_INET;
194 // FIXME: Should we populate the hostent's address list here with a sockaddr_in for the provided host?
195 __gethostbyaddr_address_list_buffer[0] = nullptr;
196 __gethostbyaddr_buffer.h_addr_list = (char**)__gethostbyaddr_address_list_buffer;
197 __gethostbyaddr_buffer.h_length = 4;
198
199 return &__gethostbyaddr_buffer;
200}
201
202struct servent* getservbyname(const char* name, const char* protocol)
203{
204 dbg() << "FIXME: getservbyname(\"" << name << "\", \"" << protocol << "\")";
205 ASSERT_NOT_REACHED();
206}
207
208}