1 /* $OpenBSD: canohost.c,v 1.76 2023/03/03 05:00:34 djm 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 "includes.h" 16 17 #include <sys/types.h> 18 #include <sys/socket.h> 19 #include <sys/un.h> 20 21 #include <netinet/in.h> 22 #include <arpa/inet.h> 23 24 #include <errno.h> 25 #include <netdb.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <stdarg.h> 30 #include <unistd.h> 31 32 #include "xmalloc.h" 33 #include "packet.h" 34 #include "log.h" 35 #include "canohost.h" 36 #include "misc.h" 37 38 void 39 ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len) 40 { 41 struct sockaddr_in6 *a6 = (struct sockaddr_in6 *)addr; 42 struct sockaddr_in *a4 = (struct sockaddr_in *)addr; 43 struct in_addr inaddr; 44 u_int16_t port; 45 46 if (addr->ss_family != AF_INET6 || 47 !IN6_IS_ADDR_V4MAPPED(&a6->sin6_addr)) 48 return; 49 50 debug3("Normalising mapped IPv4 in IPv6 address"); 51 52 memcpy(&inaddr, ((char *)&a6->sin6_addr) + 12, sizeof(inaddr)); 53 port = a6->sin6_port; 54 55 memset(a4, 0, sizeof(*a4)); 56 57 a4->sin_family = AF_INET; 58 *len = sizeof(*a4); 59 memcpy(&a4->sin_addr, &inaddr, sizeof(inaddr)); 60 a4->sin_port = port; 61 } 62 63 /* 64 * Returns the local/remote IP-address/hostname of socket as a string. 65 * The returned string must be freed. 66 */ 67 static char * 68 get_socket_address(int sock, int remote, int flags) 69 { 70 struct sockaddr_storage addr; 71 socklen_t addrlen; 72 char ntop[NI_MAXHOST]; 73 int r; 74 75 if (sock < 0) 76 return NULL; 77 78 /* Get IP address of client. */ 79 addrlen = sizeof(addr); 80 memset(&addr, 0, sizeof(addr)); 81 82 if (remote) { 83 if (getpeername(sock, (struct sockaddr *)&addr, &addrlen) != 0) 84 return NULL; 85 } else { 86 if (getsockname(sock, (struct sockaddr *)&addr, &addrlen) != 0) 87 return NULL; 88 } 89 90 /* Work around Linux IPv6 weirdness */ 91 if (addr.ss_family == AF_INET6) { 92 addrlen = sizeof(struct sockaddr_in6); 93 ipv64_normalise_mapped(&addr, &addrlen); 94 } 95 96 switch (addr.ss_family) { 97 case AF_INET: 98 case AF_INET6: 99 /* Get the address in ascii. */ 100 if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop, 101 sizeof(ntop), NULL, 0, flags)) != 0) { 102 error_f("getnameinfo %d failed: %s", 103 flags, ssh_gai_strerror(r)); 104 return NULL; 105 } 106 return xstrdup(ntop); 107 case AF_UNIX: 108 /* Get the Unix domain socket path. */ 109 return xstrdup(((struct sockaddr_un *)&addr)->sun_path); 110 default: 111 /* We can't look up remote Unix domain sockets. */ 112 return NULL; 113 } 114 } 115 116 char * 117 get_peer_ipaddr(int sock) 118 { 119 char *p; 120 121 if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL) 122 return p; 123 return xstrdup("UNKNOWN"); 124 } 125 126 char * 127 get_local_ipaddr(int sock) 128 { 129 char *p; 130 131 if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL) 132 return p; 133 return xstrdup("UNKNOWN"); 134 } 135 136 char * 137 get_local_name(int fd) 138 { 139 char *host, myname[NI_MAXHOST]; 140 141 /* Assume we were passed a socket */ 142 if ((host = get_socket_address(fd, 0, NI_NAMEREQD)) != NULL) 143 return host; 144 145 /* Handle the case where we were passed a pipe */ 146 if (gethostname(myname, sizeof(myname)) == -1) { 147 verbose_f("gethostname: %s", strerror(errno)); 148 host = xstrdup("UNKNOWN"); 149 } else { 150 host = xstrdup(myname); 151 } 152 153 return host; 154 } 155 156 /* Returns the local/remote port for the socket. */ 157 158 static int 159 get_sock_port(int sock, int local) 160 { 161 struct sockaddr_storage from; 162 socklen_t fromlen; 163 char strport[NI_MAXSERV]; 164 int r; 165 166 /* Get IP address of client. */ 167 fromlen = sizeof(from); 168 memset(&from, 0, sizeof(from)); 169 if (local) { 170 if (getsockname(sock, (struct sockaddr *)&from, &fromlen) == -1) { 171 error("getsockname failed: %.100s", strerror(errno)); 172 return 0; 173 } 174 } else { 175 if (getpeername(sock, (struct sockaddr *)&from, &fromlen) == -1) { 176 debug("getpeername failed: %.100s", strerror(errno)); 177 return -1; 178 } 179 } 180 181 /* Work around Linux IPv6 weirdness */ 182 if (from.ss_family == AF_INET6) 183 fromlen = sizeof(struct sockaddr_in6); 184 185 /* Non-inet sockets don't have a port number. */ 186 if (from.ss_family != AF_INET && from.ss_family != AF_INET6) 187 return 0; 188 189 /* Return port number. */ 190 if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0, 191 strport, sizeof(strport), NI_NUMERICSERV)) != 0) 192 fatal_f("getnameinfo NI_NUMERICSERV failed: %s", 193 ssh_gai_strerror(r)); 194 return atoi(strport); 195 } 196 197 int 198 get_peer_port(int sock) 199 { 200 return get_sock_port(sock, 0); 201 } 202 203 int 204 get_local_port(int sock) 205 { 206 return get_sock_port(sock, 1); 207 } 208