1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /*
3 * Copyright (C) 2001,2005 by the Massachusetts Institute of Technology,
4 * Cambridge, MA, USA. All Rights Reserved.
5 *
6 * This software is being provided to you, the LICENSEE, by the
7 * Massachusetts Institute of Technology (M.I.T.) under the following
8 * license. By obtaining, using and/or copying this software, you agree
9 * that you have read, understood, and will comply with these terms and
10 * conditions:
11 *
12 * Export of this software from the United States of America may
13 * require a specific license from the United States Government.
14 * It is the responsibility of any person or organization contemplating
15 * export to obtain such a license before exporting.
16 *
17 * WITHIN THAT CONSTRAINT, permission to use, copy, modify and distribute
18 * this software and its documentation for any purpose and without fee or
19 * royalty is hereby granted, provided that you agree to comply with the
20 * following copyright notice and statements, including the disclaimer, and
21 * that the same appear on ALL copies of the software and documentation,
22 * including modifications that you make for internal use or for
23 * distribution:
24 *
25 * THIS SOFTWARE IS PROVIDED "AS IS", AND M.I.T. MAKES NO REPRESENTATIONS
26 * OR WARRANTIES, EXPRESS OR IMPLIED. By way of example, but not
27 * limitation, M.I.T. MAKES NO REPRESENTATIONS OR WARRANTIES OF
28 * MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF
29 * THE LICENSED SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY
30 * PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
31 *
32 * The name of the Massachusetts Institute of Technology or M.I.T. may NOT
33 * be used in advertising or publicity pertaining to distribution of the
34 * software. Title to copyright in this software and any associated
35 * documentation shall at all times remain with M.I.T., and USER agrees to
36 * preserve same.
37 *
38 * Furthermore if you modify this software you must label
39 * your software as modified software and not distribute it in such a
40 * fashion that it might be confused with the original M.I.T. software.
41 */
42
43 #ifndef SOCKET_UTILS_H
44 #define SOCKET_UTILS_H
45
46 #include <stdbool.h>
47
48 /* Some useful stuff cross-platform for manipulating socket addresses.
49 We assume at least ipv4 sockaddr_in support. The sockaddr_storage
50 stuff comes from the ipv6 socket api enhancements; socklen_t is
51 provided on some systems; the rest is just convenience for internal
52 use in the krb5 tree.
53
54 Do NOT install this file. */
55
56 /* for HAVE_SOCKLEN_T etc */
57 #include "autoconf.h"
58 /* for sockaddr_storage */
59 #include "port-sockets.h"
60 /* for "inline" if needed */
61 #include "k5-platform.h"
62
63 /*
64 * There's a lot of confusion between pointers to different sockaddr
65 * types, and pointers with different degrees of indirection, as in
66 * the locate_kdc type functions. Use these function to ensure we
67 * don't do something silly like cast a "sockaddr **" to a
68 * "sockaddr_in *".
69 *
70 * The casts to (void *) are to get GCC to shut up about alignment
71 * increasing. We assume that struct sockaddr pointers are generally
72 * read-only; there are a few exceptions, but they all go through
73 * sa_setport().
74 */
sa2sin(const struct sockaddr * sa)75 static inline const struct sockaddr_in *sa2sin(const struct sockaddr *sa)
76 {
77 return (const struct sockaddr_in *)(void *)sa;
78 }
sa2sin6(const struct sockaddr * sa)79 static inline const struct sockaddr_in6 *sa2sin6(const struct sockaddr *sa)
80 {
81 return (const struct sockaddr_in6 *)(void *)sa;
82 }
ss2sa(struct sockaddr_storage * ss)83 static inline struct sockaddr *ss2sa (struct sockaddr_storage *ss)
84 {
85 return (struct sockaddr *) ss;
86 }
ss2sin(struct sockaddr_storage * ss)87 static inline struct sockaddr_in *ss2sin (struct sockaddr_storage *ss)
88 {
89 return (struct sockaddr_in *) ss;
90 }
ss2sin6(struct sockaddr_storage * ss)91 static inline struct sockaddr_in6 *ss2sin6 (struct sockaddr_storage *ss)
92 {
93 return (struct sockaddr_in6 *) ss;
94 }
95 #ifndef _WIN32
sa2sun(const struct sockaddr * sa)96 static inline const struct sockaddr_un *sa2sun(const struct sockaddr *sa)
97 {
98 return (const struct sockaddr_un *)(void *)sa;
99 }
ss2sun(struct sockaddr_storage * ss)100 static inline struct sockaddr_un *ss2sun(struct sockaddr_storage *ss)
101 {
102 return (struct sockaddr_un *)ss;
103 }
104 #endif
105
106 /* Set the IPv4 or IPv6 port on sa to port. Do nothing if sa is not an
107 * Internet socket. */
108 static inline void
sa_setport(struct sockaddr * sa,uint16_t port)109 sa_setport(struct sockaddr *sa, uint16_t port)
110 {
111 if (sa->sa_family == AF_INET)
112 ((struct sockaddr_in *)sa2sin(sa))->sin_port = htons(port);
113 else if (sa->sa_family == AF_INET6)
114 ((struct sockaddr_in6 *)sa2sin6(sa))->sin6_port = htons(port);
115 }
116
117 /* Get the Internet port number of sa, or 0 if it is not an Internet socket. */
118 static inline uint16_t
sa_getport(const struct sockaddr * sa)119 sa_getport(const struct sockaddr *sa)
120 {
121 if (sa->sa_family == AF_INET)
122 return ntohs(sa2sin(sa)->sin_port);
123 else if (sa->sa_family == AF_INET6)
124 return ntohs(sa2sin6(sa)->sin6_port);
125 else
126 return 0;
127 }
128
129 /* Return true if sa is an IPv4 or IPv6 socket address. */
130 static inline int
sa_is_inet(const struct sockaddr * sa)131 sa_is_inet(const struct sockaddr *sa)
132 {
133 return sa->sa_family == AF_INET || sa->sa_family == AF_INET6;
134 }
135
136 /* Return true if sa is an IPv4 or IPv6 wildcard address. */
137 static inline int
sa_is_wildcard(const struct sockaddr * sa)138 sa_is_wildcard(const struct sockaddr *sa)
139 {
140 if (sa->sa_family == AF_INET6)
141 return IN6_IS_ADDR_UNSPECIFIED(&sa2sin6(sa)->sin6_addr);
142 else if (sa->sa_family == AF_INET)
143 return sa2sin(sa)->sin_addr.s_addr == INADDR_ANY;
144 return 0;
145 }
146
147 /* Return the length of an IPv4 or IPv6 socket structure; abort if it is
148 * neither. */
149 static inline socklen_t
sa_socklen(const struct sockaddr * sa)150 sa_socklen(const struct sockaddr *sa)
151 {
152 if (sa->sa_family == AF_INET6)
153 return sizeof(struct sockaddr_in6);
154 else if (sa->sa_family == AF_INET)
155 return sizeof(struct sockaddr_in);
156 #ifndef _WIN32
157 else if (sa->sa_family == AF_UNIX)
158 return sizeof(struct sockaddr_un);
159 #endif
160 else
161 abort();
162 }
163
164 /* Return true if a and b are the same address (and port if applicable). */
165 static inline bool
sa_equal(const struct sockaddr * a,const struct sockaddr * b)166 sa_equal(const struct sockaddr *a, const struct sockaddr *b)
167 {
168 if (a == NULL || b == NULL || a->sa_family != b->sa_family)
169 return false;
170
171 if (a->sa_family == AF_INET) {
172 const struct sockaddr_in *x = sa2sin(a);
173 const struct sockaddr_in *y = sa2sin(b);
174
175 if (x->sin_port != y->sin_port)
176 return false;
177 return memcmp(&x->sin_addr, &y->sin_addr, sizeof(x->sin_addr)) == 0;
178 } else if (a->sa_family == AF_INET6) {
179 const struct sockaddr_in6 *x = sa2sin6(a);
180 const struct sockaddr_in6 *y = sa2sin6(b);
181
182 if (x->sin6_port != y->sin6_port)
183 return false;
184 return memcmp(&x->sin6_addr, &y->sin6_addr, sizeof(x->sin6_addr)) == 0;
185 #ifndef _WIN32
186 } else if (a->sa_family == AF_UNIX) {
187 const struct sockaddr_un *x = sa2sun(a);
188 const struct sockaddr_un *y = sa2sun(b);
189
190 return strcmp(x->sun_path, y->sun_path) == 0;
191 #endif
192 }
193
194 return false;
195 }
196
197 #endif /* SOCKET_UTILS_H */
198