1 /* $NetBSD: canohost.c,v 1.16 2023/10/25 20:19:57 christos Exp $ */
2 /* $OpenBSD: canohost.c,v 1.77 2023/03/31 04:42:29 dtucker Exp $ */
3
4 /*
5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
6 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7 * All rights reserved
8 * Functions for returning the canonical host name of the remote site.
9 *
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
15 */
16
17 #include "includes.h"
18 __RCSID("$NetBSD: canohost.c,v 1.16 2023/10/25 20:19:57 christos Exp $");
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <sys/un.h>
22
23 #include <netinet/in.h>
24
25 #include <errno.h>
26 #include <netdb.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <stdarg.h>
31 #include <time.h>
32 #include <unistd.h>
33
34 #include "xmalloc.h"
35 #include "packet.h"
36 #include "log.h"
37 #include "canohost.h"
38 #include "misc.h"
39
40 /*
41 * Returns the local/remote IP-address/hostname of socket as a string.
42 * The returned string must be freed.
43 */
44 static char *
get_socket_address(int sock,int remote,int flags)45 get_socket_address(int sock, int remote, int flags)
46 {
47 struct sockaddr_storage addr;
48 socklen_t addrlen;
49 char ntop[NI_MAXHOST];
50 int r;
51
52 if (sock < 0)
53 return NULL;
54
55 /* Get IP address of client. */
56 addrlen = sizeof(addr);
57 memset(&addr, 0, sizeof(addr));
58
59 if (remote) {
60 if (getpeername(sock, (struct sockaddr *)&addr, &addrlen) != 0)
61 return NULL;
62 } else {
63 if (getsockname(sock, (struct sockaddr *)&addr, &addrlen) != 0)
64 return NULL;
65 }
66
67 switch (addr.ss_family) {
68 case AF_INET:
69 case AF_INET6:
70 /* Get the address in ascii. */
71 if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop,
72 sizeof(ntop), NULL, 0, flags)) != 0) {
73 error_f("getnameinfo %d failed: %s",
74 flags, ssh_gai_strerror(r));
75 return NULL;
76 }
77 return xstrdup(ntop);
78 case AF_UNIX:
79 /* Get the Unix domain socket path. */
80 return xstrdup(((struct sockaddr_un *)&addr)->sun_path);
81 default:
82 /* We can't look up remote Unix domain sockets. */
83 return NULL;
84 }
85 }
86
87 char *
get_peer_ipaddr(int sock)88 get_peer_ipaddr(int sock)
89 {
90 char *p;
91
92 if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL)
93 return p;
94 return xstrdup("UNKNOWN");
95 }
96
97 char *
get_local_ipaddr(int sock)98 get_local_ipaddr(int sock)
99 {
100 char *p;
101
102 if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL)
103 return p;
104 return xstrdup("UNKNOWN");
105 }
106
107 char *
get_local_name(int fd)108 get_local_name(int fd)
109 {
110 char *host, myname[NI_MAXHOST];
111
112 /* Assume we were passed a socket */
113 if ((host = get_socket_address(fd, 0, NI_NAMEREQD)) != NULL)
114 return host;
115
116 /* Handle the case where we were passed a pipe */
117 if (gethostname(myname, sizeof(myname)) == -1) {
118 verbose_f("gethostname: %s", strerror(errno));
119 host = xstrdup("UNKNOWN");
120 } else {
121 host = xstrdup(myname);
122 }
123
124 return host;
125 }
126
127 /* Returns the local/remote port for the socket. */
128
129 static int
get_sock_port(int sock,int local)130 get_sock_port(int sock, int local)
131 {
132 struct sockaddr_storage from;
133 socklen_t fromlen;
134 char strport[NI_MAXSERV];
135 int r;
136
137 if (sock < 0)
138 return -1;
139 /* Get IP address of client. */
140 fromlen = sizeof(from);
141 memset(&from, 0, sizeof(from));
142 if (local) {
143 if (getsockname(sock, (struct sockaddr *)&from, &fromlen) == -1) {
144 error("getsockname failed: %.100s", strerror(errno));
145 return 0;
146 }
147 } else {
148 if (getpeername(sock, (struct sockaddr *)&from, &fromlen) == -1) {
149 debug("getpeername failed: %.100s", strerror(errno));
150 return -1;
151 }
152 }
153
154 /* Non-inet sockets don't have a port number. */
155 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
156 return 0;
157
158 /* Return port number. */
159 if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0,
160 strport, sizeof(strport), NI_NUMERICSERV)) != 0)
161 fatal_f("getnameinfo NI_NUMERICSERV failed: %s",
162 ssh_gai_strerror(r));
163 return atoi(strport);
164 }
165
166 int
get_peer_port(int sock)167 get_peer_port(int sock)
168 {
169 return get_sock_port(sock, 0);
170 }
171
172 int
get_local_port(int sock)173 get_local_port(int sock)
174 {
175 return get_sock_port(sock, 1);
176 }
177