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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> | |
25f300f7 | 25 | #include <libloc/compat.h> |
0a0a289a MT |
26 | |
27 | #define LOC_ADDRESS_BUFFERS 6 | |
28 | #define LOC_ADDRESS_BUFFER_LENGTH INET6_ADDRSTRLEN | |
29 | ||
b0f572df | 30 | static char __loc_address_buffers[LOC_ADDRESS_BUFFERS][LOC_ADDRESS_BUFFER_LENGTH + 1]; |
0a0a289a MT |
31 | static int __loc_address_buffer_idx = 0; |
32 | ||
33 | static const char* __loc_address6_str(const struct in6_addr* address, char* buffer, size_t length) { | |
34 | return inet_ntop(AF_INET6, address, buffer, length); | |
35 | } | |
36 | ||
37 | static const char* __loc_address4_str(const struct in6_addr* address, char* buffer, size_t length) { | |
38 | struct in_addr address4 = { | |
39 | .s_addr = address->s6_addr32[3], | |
40 | }; | |
41 | ||
42 | return inet_ntop(AF_INET, &address4, buffer, length); | |
43 | } | |
44 | ||
45 | const char* loc_address_str(const struct in6_addr* address) { | |
46 | if (!address) | |
47 | return NULL; | |
48 | ||
49 | // Select buffer | |
50 | char* buffer = __loc_address_buffers[__loc_address_buffer_idx++]; | |
51 | ||
52 | // Prevent index from overflow | |
53 | __loc_address_buffer_idx %= LOC_ADDRESS_BUFFERS; | |
54 | ||
55 | if (IN6_IS_ADDR_V4MAPPED(address)) | |
56 | return __loc_address4_str(address, buffer, LOC_ADDRESS_BUFFER_LENGTH); | |
57 | else | |
58 | return __loc_address6_str(address, buffer, LOC_ADDRESS_BUFFER_LENGTH); | |
59 | } | |
95b6a8e4 MT |
60 | |
61 | static void loc_address_from_address4(struct in6_addr* address, | |
62 | const struct in_addr* address4) { | |
63 | address->s6_addr32[0] = 0; | |
64 | address->s6_addr32[1] = 0; | |
65 | address->s6_addr32[2] = htonl(0xffff); | |
66 | address->s6_addr32[3] = address4->s_addr; | |
67 | } | |
68 | ||
69 | int loc_address_parse(struct in6_addr* address, unsigned int* prefix, const char* string) { | |
70 | char buffer[INET6_ADDRSTRLEN + 4]; | |
71 | int r; | |
72 | ||
73 | if (!address || !string) { | |
74 | errno = EINVAL; | |
75 | return 1; | |
76 | } | |
77 | ||
78 | // Copy the string into the buffer | |
79 | r = snprintf(buffer, sizeof(buffer) - 1, "%s", string); | |
80 | if (r < 0) | |
81 | return 1; | |
82 | ||
83 | // Find / | |
84 | char* p = strchr(buffer, '/'); | |
85 | if (p) { | |
86 | // Terminate the IP address | |
87 | *p++ = '\0'; | |
88 | } | |
89 | ||
90 | int family = AF_UNSPEC; | |
91 | ||
92 | // Try parsing as an IPv6 address | |
93 | r = inet_pton(AF_INET6, buffer, address); | |
94 | switch (r) { | |
95 | // This is not a valid IPv6 address | |
96 | case 0: | |
97 | break; | |
98 | ||
99 | // This is a valid IPv6 address | |
100 | case 1: | |
101 | family = AF_INET6; | |
102 | break; | |
103 | ||
104 | // Unexpected error | |
105 | default: | |
106 | return 1; | |
107 | } | |
108 | ||
109 | // Try parsing as an IPv4 address | |
110 | if (!family) { | |
111 | struct in_addr address4; | |
112 | ||
113 | r = inet_pton(AF_INET, buffer, &address4); | |
114 | switch (r) { | |
115 | // This was not a valid IPv4 address | |
116 | case 0: | |
117 | break; | |
118 | ||
119 | // This was a valid IPv4 address | |
120 | case 1: | |
121 | family = AF_INET; | |
122 | ||
123 | // Copy the result | |
124 | loc_address_from_address4(address, &address4); | |
125 | break; | |
126 | ||
127 | // Unexpected error | |
128 | default: | |
129 | return 1; | |
130 | } | |
131 | } | |
132 | ||
133 | // Invalid input | |
134 | if (family == AF_UNSPEC) { | |
135 | errno = EINVAL; | |
136 | return 1; | |
137 | } | |
138 | ||
139 | // Did the user request a prefix? | |
140 | if (prefix) { | |
141 | // Set the prefix to the default value | |
17e3d8fd | 142 | const unsigned int max_prefix = loc_address_family_bit_length(family); |
95b6a8e4 MT |
143 | |
144 | // Parse the actual string | |
17e3d8fd | 145 | if (p) { |
95b6a8e4 | 146 | *prefix = strtol(p, NULL, 10); |
17e3d8fd MT |
147 | |
148 | // Check if prefix is within bounds | |
149 | if (*prefix > max_prefix) { | |
150 | errno = EINVAL; | |
151 | return 1; | |
152 | } | |
153 | ||
154 | // If the string didn't contain a prefix, we set the maximum | |
155 | } else { | |
156 | *prefix = max_prefix; | |
157 | } | |
95b6a8e4 MT |
158 | } |
159 | ||
160 | return 0; | |
161 | } |