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0a0a289a MT |
1 | /* |
2 | libloc - A library to determine the location of someone on the Internet | |
3 | ||
4 | Copyright (C) 2022 IPFire Development Team <info@ipfire.org> | |
5 | ||
6 | This library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | This library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <arpa/inet.h> | |
18 | #include <netinet/in.h> | |
19 | #include <stddef.h> | |
95b6a8e4 MT |
20 | #include <stdio.h> |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
0a0a289a MT |
23 | |
24 | #include <libloc/address.h> | |
25 | ||
26 | #define LOC_ADDRESS_BUFFERS 6 | |
27 | #define LOC_ADDRESS_BUFFER_LENGTH INET6_ADDRSTRLEN | |
28 | ||
b0f572df | 29 | static char __loc_address_buffers[LOC_ADDRESS_BUFFERS][LOC_ADDRESS_BUFFER_LENGTH + 1]; |
0a0a289a MT |
30 | static int __loc_address_buffer_idx = 0; |
31 | ||
32 | static const char* __loc_address6_str(const struct in6_addr* address, char* buffer, size_t length) { | |
33 | return inet_ntop(AF_INET6, address, buffer, length); | |
34 | } | |
35 | ||
36 | static const char* __loc_address4_str(const struct in6_addr* address, char* buffer, size_t length) { | |
37 | struct in_addr address4 = { | |
38 | .s_addr = address->s6_addr32[3], | |
39 | }; | |
40 | ||
41 | return inet_ntop(AF_INET, &address4, buffer, length); | |
42 | } | |
43 | ||
44 | const char* loc_address_str(const struct in6_addr* address) { | |
45 | if (!address) | |
46 | return NULL; | |
47 | ||
48 | // Select buffer | |
49 | char* buffer = __loc_address_buffers[__loc_address_buffer_idx++]; | |
50 | ||
51 | // Prevent index from overflow | |
52 | __loc_address_buffer_idx %= LOC_ADDRESS_BUFFERS; | |
53 | ||
54 | if (IN6_IS_ADDR_V4MAPPED(address)) | |
55 | return __loc_address4_str(address, buffer, LOC_ADDRESS_BUFFER_LENGTH); | |
56 | else | |
57 | return __loc_address6_str(address, buffer, LOC_ADDRESS_BUFFER_LENGTH); | |
58 | } | |
95b6a8e4 MT |
59 | |
60 | static void loc_address_from_address4(struct in6_addr* address, | |
61 | const struct in_addr* address4) { | |
62 | address->s6_addr32[0] = 0; | |
63 | address->s6_addr32[1] = 0; | |
64 | address->s6_addr32[2] = htonl(0xffff); | |
65 | address->s6_addr32[3] = address4->s_addr; | |
66 | } | |
67 | ||
68 | int loc_address_parse(struct in6_addr* address, unsigned int* prefix, const char* string) { | |
69 | char buffer[INET6_ADDRSTRLEN + 4]; | |
70 | int r; | |
71 | ||
72 | if (!address || !string) { | |
73 | errno = EINVAL; | |
74 | return 1; | |
75 | } | |
76 | ||
77 | // Copy the string into the buffer | |
78 | r = snprintf(buffer, sizeof(buffer) - 1, "%s", string); | |
79 | if (r < 0) | |
80 | return 1; | |
81 | ||
82 | // Find / | |
83 | char* p = strchr(buffer, '/'); | |
84 | if (p) { | |
85 | // Terminate the IP address | |
86 | *p++ = '\0'; | |
87 | } | |
88 | ||
89 | int family = AF_UNSPEC; | |
90 | ||
91 | // Try parsing as an IPv6 address | |
92 | r = inet_pton(AF_INET6, buffer, address); | |
93 | switch (r) { | |
94 | // This is not a valid IPv6 address | |
95 | case 0: | |
96 | break; | |
97 | ||
98 | // This is a valid IPv6 address | |
99 | case 1: | |
100 | family = AF_INET6; | |
101 | break; | |
102 | ||
103 | // Unexpected error | |
104 | default: | |
105 | return 1; | |
106 | } | |
107 | ||
108 | // Try parsing as an IPv4 address | |
109 | if (!family) { | |
110 | struct in_addr address4; | |
111 | ||
112 | r = inet_pton(AF_INET, buffer, &address4); | |
113 | switch (r) { | |
114 | // This was not a valid IPv4 address | |
115 | case 0: | |
116 | break; | |
117 | ||
118 | // This was a valid IPv4 address | |
119 | case 1: | |
120 | family = AF_INET; | |
121 | ||
122 | // Copy the result | |
123 | loc_address_from_address4(address, &address4); | |
124 | break; | |
125 | ||
126 | // Unexpected error | |
127 | default: | |
128 | return 1; | |
129 | } | |
130 | } | |
131 | ||
132 | // Invalid input | |
133 | if (family == AF_UNSPEC) { | |
134 | errno = EINVAL; | |
135 | return 1; | |
136 | } | |
137 | ||
138 | // Did the user request a prefix? | |
139 | if (prefix) { | |
140 | // Set the prefix to the default value | |
17e3d8fd | 141 | const unsigned int max_prefix = loc_address_family_bit_length(family); |
95b6a8e4 MT |
142 | |
143 | // Parse the actual string | |
17e3d8fd | 144 | if (p) { |
95b6a8e4 | 145 | *prefix = strtol(p, NULL, 10); |
17e3d8fd MT |
146 | |
147 | // Check if prefix is within bounds | |
148 | if (*prefix > max_prefix) { | |
149 | errno = EINVAL; | |
150 | return 1; | |
151 | } | |
152 | ||
153 | // If the string didn't contain a prefix, we set the maximum | |
154 | } else { | |
155 | *prefix = max_prefix; | |
156 | } | |
95b6a8e4 MT |
157 | } |
158 | ||
159 | return 0; | |
160 | } |