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 <sys/types.h>
20 #include <sys/socket.h>
21 #include <netinet/in.h>
22 #include <arpa/inet.h>
23
24 #include <netdb.h>
25 #include <string.h>
26 #include <stdlib.h>
27 #include <stdio.h>
28 #include <stdarg.h>
29
30 #include "addr.h"
31 #include "match.h"
32 #include "log.h"
33
34 /*
35 * Match "addr" against list pattern list "_list", which may contain a
36 * mix of CIDR addresses and old-school wildcards.
37 *
38 * If addr is NULL, then no matching is performed, but _list is parsed
39 * and checked for well-formedness.
40 *
41 * Returns 1 on match found (never returned when addr == NULL).
42 * Returns 0 on if no match found, or no errors found when addr == NULL.
43 * Returns -1 on negated match found (never returned when addr == NULL).
44 * Returns -2 on invalid list entry.
45 */
46 int
addr_match_list(const char * addr,const char * _list)47 addr_match_list(const char *addr, const char *_list)
48 {
49 char *list, *cp, *o;
50 struct xaddr try_addr, match_addr;
51 u_int masklen, neg;
52 int ret = 0, r;
53
54 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
55 debug2_f("couldn't parse address %.100s", addr);
56 return 0;
57 }
58 if ((o = list = strdup(_list)) == NULL)
59 return -1;
60 while ((cp = strsep(&list, ",")) != NULL) {
61 neg = *cp == '!';
62 if (neg)
63 cp++;
64 if (*cp == '\0') {
65 ret = -2;
66 break;
67 }
68 /* Prefer CIDR address matching */
69 r = addr_pton_cidr(cp, &match_addr, &masklen);
70 if (r == -2) {
71 debug2_f("inconsistent mask length for "
72 "match network \"%.100s\"", cp);
73 ret = -2;
74 break;
75 } else if (r == 0) {
76 if (addr != NULL && addr_netmatch(&try_addr,
77 &match_addr, masklen) == 0) {
78 foundit:
79 if (neg) {
80 ret = -1;
81 break;
82 }
83 ret = 1;
84 }
85 continue;
86 } else {
87 /* If CIDR parse failed, try wildcard string match */
88 if (addr != NULL && match_pattern(addr, cp) == 1)
89 goto foundit;
90 }
91 }
92 free(o);
93
94 return ret;
95 }
96
97 /*
98 * Match "addr" against list CIDR list "_list". Lexical wildcards and
99 * negation are not supported. If "addr" == NULL, will verify structure
100 * of "_list".
101 *
102 * Returns 1 on match found (never returned when addr == NULL).
103 * Returns 0 on if no match found, or no errors found when addr == NULL.
104 * Returns -1 on error
105 */
106 int
addr_match_cidr_list(const char * addr,const char * _list)107 addr_match_cidr_list(const char *addr, const char *_list)
108 {
109 char *list, *cp, *o;
110 struct xaddr try_addr, match_addr;
111 u_int masklen;
112 int ret = 0, r;
113
114 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
115 debug2_f("couldn't parse address %.100s", addr);
116 return 0;
117 }
118 if ((o = list = strdup(_list)) == NULL)
119 return -1;
120 while ((cp = strsep(&list, ",")) != NULL) {
121 if (*cp == '\0') {
122 error_f("empty entry in list \"%.100s\"", o);
123 ret = -1;
124 break;
125 }
126
127 /*
128 * NB. This function is called in pre-auth with untrusted data,
129 * so be extra paranoid about junk reaching getaddrino (via
130 * addr_pton_cidr).
131 */
132
133 /* Stop junk from reaching getaddrinfo. +3 is for masklen */
134 if (strlen(cp) > INET6_ADDRSTRLEN + 3) {
135 error_f("list entry \"%.100s\" too long", cp);
136 ret = -1;
137 break;
138 }
139 #define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/"
140 if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) {
141 error_f("list entry \"%.100s\" contains invalid "
142 "characters", cp);
143 ret = -1;
144 }
145
146 /* Prefer CIDR address matching */
147 r = addr_pton_cidr(cp, &match_addr, &masklen);
148 if (r == -1) {
149 error("Invalid network entry \"%.100s\"", cp);
150 ret = -1;
151 break;
152 } else if (r == -2) {
153 error("Inconsistent mask length for "
154 "network \"%.100s\"", cp);
155 ret = -1;
156 break;
157 } else if (r == 0 && addr != NULL) {
158 if (addr_netmatch(&try_addr, &match_addr,
159 masklen) == 0)
160 ret = 1;
161 continue;
162 }
163 }
164 free(o);
165
166 return ret;
167 }
168