1 /* $NetBSD: sock_addr.c,v 1.4 2025/02/25 19:15:52 christos Exp $ */
2
3 /*++
4 /* NAME
5 /* sock_addr 3
6 /* SUMMARY
7 /* sockaddr utilities
8 /* SYNOPSIS
9 /* #include <sock_addr.h>
10 /*
11 /* int sock_addr_cmp_addr(sa, sb)
12 /* const struct sockaddr *sa;
13 /* const struct sockaddr *sb;
14 /*
15 /* int sock_addr_cmp_port(sa, sb)
16 /* const struct sockaddr *sa;
17 /* const struct sockaddr *sb;
18 /*
19 /* int SOCK_ADDR_EQ_ADDR(sa, sb)
20 /* const struct sockaddr *sa;
21 /* const struct sockaddr *sb;
22 /*
23 /* int SOCK_ADDR_EQ_PORT(sa, sb)
24 /* const struct sockaddr *sa;
25 /* const struct sockaddr *sb;
26 /*
27 /* int sock_addr_in_loopback(sa)
28 /* const struct sockaddr *sa;
29 /* AUXILIARY MACROS
30 /* struct sockaddr *SOCK_ADDR_PTR(ptr)
31 /* unsigned char SOCK_ADDR_FAMILY(ptr)
32 /* unsigned char SOCK_ADDR_LEN(ptr)
33 /* void *SOCK_ADDR_ADDRP(ptr)
34 /* unsigned short SOCK_ADDR_PORT(ptr)
35 /* unsigned short *SOCK_ADDR_PORTP(ptr)
36 /*
37 /* struct sockaddr_in *SOCK_ADDR_IN_PTR(ptr)
38 /* unsigned char SOCK_ADDR_IN_FAMILY(ptr)
39 /* unsigned short SOCK_ADDR_IN_PORT(ptr)
40 /* struct in_addr SOCK_ADDR_IN_ADDR(ptr)
41 /* struct in_addr IN_ADDR(ptr)
42 /*
43 /* struct sockaddr_in6 *SOCK_ADDR_IN6_PTR(ptr)
44 /* unsigned char SOCK_ADDR_IN6_FAMILY(ptr)
45 /* unsigned short SOCK_ADDR_IN6_PORT(ptr)
46 /* struct in6_addr SOCK_ADDR_IN6_ADDR(ptr)
47 /* struct in6_addr IN6_ADDR(ptr)
48 /* DESCRIPTION
49 /* These utilities take protocol-independent address structures
50 /* and perform protocol-dependent operations on structure members.
51 /* Some of the macros described here are called unsafe,
52 /* because they evaluate one or more arguments multiple times.
53 /*
54 /* sock_addr_cmp_addr() or sock_addr_cmp_port() compare the
55 /* address family and network address or port fields for
56 /* equality, and return indication of the difference between
57 /* their arguments: < 0 if the first argument is "smaller",
58 /* 0 for equality, and > 0 if the first argument is "larger".
59 /*
60 /* The unsafe macros SOCK_ADDR_EQ_ADDR() or SOCK_ADDR_EQ_PORT()
61 /* compare compare the address family and network address or
62 /* port fields for equality, and return non-zero when their
63 /* arguments differ.
64 /*
65 /* sock_addr_in_loopback() determines if the argument specifies
66 /* a loopback address.
67 /*
68 /* The SOCK_ADDR_PTR() macro casts a generic pointer to (struct
69 /* sockaddr *). The name is upper case for consistency not
70 /* safety. SOCK_ADDR_FAMILY() and SOCK_ADDR_LEN() return the
71 /* address family and length of the real structure that hides
72 /* inside a generic sockaddr structure. On systems where struct
73 /* sockaddr has no sa_len member, SOCK_ADDR_LEN() cannot be
74 /* used as lvalue. SOCKADDR_ADDRP() returns a pointer to the
75 /* IPv4 or IPv6 address. SOCK_ADDR_PORT() returns the IPv4 or IPv6
76 /* port number, in network byte order; it must not be used as
77 /* lvalue. SOCK_ADDR_PORTP() returns a pointer to the same.
78 /*
79 /* The macros SOCK_ADDR_IN{,6}_{PTR,FAMILY,PORT,ADDR}() cast
80 /* a generic pointer to a specific socket address structure
81 /* pointer, or access a specific socket address structure
82 /* member. These can be used as lvalues.
83 /*
84 /* The unsafe INADDR() and IN6_ADDR() macros dereference a
85 /* generic pointer to a specific address structure.
86 /* DIAGNOSTICS
87 /* Panic: unsupported address family.
88 /* LICENSE
89 /* .ad
90 /* .fi
91 /* The Secure Mailer license must be distributed with this software.
92 /* AUTHOR(S)
93 /* Wietse Venema
94 /* IBM T.J. Watson Research
95 /* P.O. Box 704
96 /* Yorktown Heights, NY 10598, USA
97 /*--*/
98
99 /* System library. */
100
101 #include <sys_defs.h>
102 #include <sys/socket.h>
103 #include <netinet/in.h>
104 #include <string.h>
105
106 /* Utility library. */
107
108 #include <msg.h>
109 #include <sock_addr.h>
110
111 /* sock_addr_cmp_addr - compare addresses for equality */
112
sock_addr_cmp_addr(const struct sockaddr * sa,const struct sockaddr * sb)113 int sock_addr_cmp_addr(const struct sockaddr *sa,
114 const struct sockaddr *sb)
115 {
116 if (sa->sa_family != sb->sa_family)
117 return (sa->sa_family - sb->sa_family);
118
119 /*
120 * With IPv6 address structures, assume a non-hostile implementation that
121 * stores the address as a contiguous sequence of bits. Any holes in the
122 * sequence would invalidate the use of memcmp().
123 */
124 if (sa->sa_family == AF_INET) {
125 return (SOCK_ADDR_IN_ADDR(sa).s_addr - SOCK_ADDR_IN_ADDR(sb).s_addr);
126 #ifdef HAS_IPV6
127 } else if (sa->sa_family == AF_INET6) {
128 return (memcmp((void *) &(SOCK_ADDR_IN6_ADDR(sa)),
129 (void *) &(SOCK_ADDR_IN6_ADDR(sb)),
130 sizeof(SOCK_ADDR_IN6_ADDR(sa))));
131 #endif
132 } else {
133 msg_panic("sock_addr_cmp_addr: unsupported address family %d",
134 sa->sa_family);
135 }
136 }
137
138 /* sock_addr_cmp_port - compare ports for equality */
139
sock_addr_cmp_port(const struct sockaddr * sa,const struct sockaddr * sb)140 int sock_addr_cmp_port(const struct sockaddr *sa,
141 const struct sockaddr *sb)
142 {
143 if (sa->sa_family != sb->sa_family)
144 return (sa->sa_family - sb->sa_family);
145
146 if (sa->sa_family == AF_INET) {
147 return (SOCK_ADDR_IN_PORT(sa) - SOCK_ADDR_IN_PORT(sb));
148 #ifdef HAS_IPV6
149 } else if (sa->sa_family == AF_INET6) {
150 return (SOCK_ADDR_IN6_PORT(sa) - SOCK_ADDR_IN6_PORT(sb));
151 #endif
152 } else {
153 msg_panic("sock_addr_cmp_port: unsupported address family %d",
154 sa->sa_family);
155 }
156 }
157
158 /* sock_addr_in_loopback - determine if address is loopback */
159
sock_addr_in_loopback(const struct sockaddr * sa)160 int sock_addr_in_loopback(const struct sockaddr *sa)
161 {
162 unsigned long inaddr;
163
164 if (sa->sa_family == AF_INET) {
165 inaddr = ntohl(SOCK_ADDR_IN_ADDR(sa).s_addr);
166 return (IN_CLASSA(inaddr)
167 && ((inaddr & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT)
168 == IN_LOOPBACKNET);
169 #ifdef HAS_IPV6
170 } else if (sa->sa_family == AF_INET6) {
171 return (IN6_IS_ADDR_LOOPBACK(&SOCK_ADDR_IN6_ADDR(sa)));
172 #endif
173 } else {
174 msg_panic("sock_addr_in_loopback: unsupported address family %d",
175 sa->sa_family);
176 }
177 }
178