1 /* $OpenBSD: addrmatch.c,v 1.17 2021/04/03 06:18:40 djm Exp $ */
2
3 /*
4 * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include "includes.h"
20
21 #include <sys/types.h>
22 #include <sys/socket.h>
23 #include <netinet/in.h>
24 #include <arpa/inet.h>
25
26 #include <netdb.h>
27 #include <string.h>
28 #include <stdlib.h>
29 #include <stdio.h>
30 #include <stdarg.h>
31
32 #include "addr.h"
33 #include "match.h"
34 #include "log.h"
35
36 /*
37 * Match "addr" against list pattern list "_list", which may contain a
38 * mix of CIDR addresses and old-school wildcards.
39 *
40 * If addr is NULL, then no matching is performed, but _list is parsed
41 * and checked for well-formedness.
42 *
43 * Returns 1 on match found (never returned when addr == NULL).
44 * Returns 0 on if no match found, or no errors found when addr == NULL.
45 * Returns -1 on negated match found (never returned when addr == NULL).
46 * Returns -2 on invalid list entry.
47 */
48 int
addr_match_list(const char * addr,const char * _list)49 addr_match_list(const char *addr, const char *_list)
50 {
51 char *list, *cp, *o;
52 struct xaddr try_addr, match_addr;
53 u_int masklen, neg;
54 int ret = 0, r;
55
56 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
57 debug2_f("couldn't parse address %.100s", addr);
58 return 0;
59 }
60 if ((o = list = strdup(_list)) == NULL)
61 return -1;
62 while ((cp = strsep(&list, ",")) != NULL) {
63 neg = *cp == '!';
64 if (neg)
65 cp++;
66 if (*cp == '\0') {
67 ret = -2;
68 break;
69 }
70 /* Prefer CIDR address matching */
71 r = addr_pton_cidr(cp, &match_addr, &masklen);
72 if (r == -2) {
73 debug2_f("inconsistent mask length for "
74 "match network \"%.100s\"", cp);
75 ret = -2;
76 break;
77 } else if (r == 0) {
78 if (addr != NULL && addr_netmatch(&try_addr,
79 &match_addr, masklen) == 0) {
80 foundit:
81 if (neg) {
82 ret = -1;
83 break;
84 }
85 ret = 1;
86 }
87 continue;
88 } else {
89 /* If CIDR parse failed, try wildcard string match */
90 if (addr != NULL && match_pattern(addr, cp) == 1)
91 goto foundit;
92 }
93 }
94 free(o);
95
96 return ret;
97 }
98
99 /*
100 * Match "addr" against list CIDR list "_list". Lexical wildcards and
101 * negation are not supported. If "addr" == NULL, will verify structure
102 * of "_list".
103 *
104 * Returns 1 on match found (never returned when addr == NULL).
105 * Returns 0 on if no match found, or no errors found when addr == NULL.
106 * Returns -1 on error
107 */
108 int
addr_match_cidr_list(const char * addr,const char * _list)109 addr_match_cidr_list(const char *addr, const char *_list)
110 {
111 char *list, *cp, *o;
112 struct xaddr try_addr, match_addr;
113 u_int masklen;
114 int ret = 0, r;
115
116 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
117 debug2_f("couldn't parse address %.100s", addr);
118 return 0;
119 }
120 if ((o = list = strdup(_list)) == NULL)
121 return -1;
122 while ((cp = strsep(&list, ",")) != NULL) {
123 if (*cp == '\0') {
124 error_f("empty entry in list \"%.100s\"", o);
125 ret = -1;
126 break;
127 }
128
129 /*
130 * NB. This function is called in pre-auth with untrusted data,
131 * so be extra paranoid about junk reaching getaddrino (via
132 * addr_pton_cidr).
133 */
134
135 /* Stop junk from reaching getaddrinfo. +3 is for masklen */
136 if (strlen(cp) > INET6_ADDRSTRLEN + 3) {
137 error_f("list entry \"%.100s\" too long", cp);
138 ret = -1;
139 break;
140 }
141 #define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/"
142 if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) {
143 error_f("list entry \"%.100s\" contains invalid "
144 "characters", cp);
145 ret = -1;
146 }
147
148 /* Prefer CIDR address matching */
149 r = addr_pton_cidr(cp, &match_addr, &masklen);
150 if (r == -1) {
151 error("Invalid network entry \"%.100s\"", cp);
152 ret = -1;
153 break;
154 } else if (r == -2) {
155 error("Inconsistent mask length for "
156 "network \"%.100s\"", cp);
157 ret = -1;
158 break;
159 } else if (r == 0 && addr != NULL) {
160 if (addr_netmatch(&try_addr, &match_addr,
161 masklen) == 0)
162 ret = 1;
163 continue;
164 }
165 }
166 free(o);
167
168 return ret;
169 }
170