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