1 /* $OpenBSD: canohost.c,v 1.73 2016/03/07 19:02:43 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo (at) cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo (at) 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 /* Get IP address of client. */ 76 addrlen = sizeof(addr); 77 memset(&addr, 0, sizeof(addr)); 78 79 if (remote) { 80 if (getpeername(sock, (struct sockaddr *)&addr, &addrlen) != 0) 81 return NULL; 82 } else { 83 if (getsockname(sock, (struct sockaddr *)&addr, &addrlen) != 0) 84 return NULL; 85 } 86 87 /* Work around Linux IPv6 weirdness */ 88 if (addr.ss_family == AF_INET6) { 89 addrlen = sizeof(struct sockaddr_in6); 90 ipv64_normalise_mapped(&addr, &addrlen); 91 } 92 93 switch (addr.ss_family) { 94 case AF_INET: 95 case AF_INET6: 96 /* Get the address in ascii. */ 97 if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop, 98 sizeof(ntop), NULL, 0, flags)) != 0) { 99 error("%s: getnameinfo %d failed: %s", __func__, 100 flags, ssh_gai_strerror(r)); 101 return NULL; 102 } 103 return xstrdup(ntop); 104 case AF_UNIX: 105 /* Get the Unix domain socket path. */ 106 return xstrdup(((struct sockaddr_un *)&addr)->sun_path); 107 default: 108 /* We can't look up remote Unix domain sockets. */ 109 return NULL; 110 } 111 } 112 113 char * 114 get_peer_ipaddr(int sock) 115 { 116 char *p; 117 118 if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL) 119 return p; 120 return xstrdup("UNKNOWN"); 121 } 122 123 char * 124 get_local_ipaddr(int sock) 125 { 126 char *p; 127 128 if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL) 129 return p; 130 return xstrdup("UNKNOWN"); 131 } 132 133 char * 134 get_local_name(int fd) 135 { 136 char *host, myname[NI_MAXHOST]; 137 138 /* Assume we were passed a socket */ 139 if ((host = get_socket_address(fd, 0, NI_NAMEREQD)) != NULL) 140 return host; 141 142 /* Handle the case where we were passed a pipe */ 143 if (gethostname(myname, sizeof(myname)) == -1) { 144 verbose("%s: gethostname: %s", __func__, strerror(errno)); 145 host = xstrdup("UNKNOWN"); 146 } else { 147 host = xstrdup(myname); 148 } 149 150 return host; 151 } 152 153 /* Returns the local/remote port for the socket. */ 154 155 static int 156 get_sock_port(int sock, int local) 157 { 158 struct sockaddr_storage from; 159 socklen_t fromlen; 160 char strport[NI_MAXSERV]; 161 int r; 162 163 /* Get IP address of client. */ 164 fromlen = sizeof(from); 165 memset(&from, 0, sizeof(from)); 166 if (local) { 167 if (getsockname(sock, (struct sockaddr *)&from, &fromlen) < 0) { 168 error("getsockname failed: %.100s", strerror(errno)); 169 return 0; 170 } 171 } else { 172 if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) { 173 debug("getpeername failed: %.100s", strerror(errno)); 174 return -1; 175 } 176 } 177 178 /* Work around Linux IPv6 weirdness */ 179 if (from.ss_family == AF_INET6) 180 fromlen = sizeof(struct sockaddr_in6); 181 182 /* Non-inet sockets don't have a port number. */ 183 if (from.ss_family != AF_INET && from.ss_family != AF_INET6) 184 return 0; 185 186 /* Return port number. */ 187 if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0, 188 strport, sizeof(strport), NI_NUMERICSERV)) != 0) 189 fatal("%s: getnameinfo NI_NUMERICSERV failed: %s", __func__, 190 ssh_gai_strerror(r)); 191 return atoi(strport); 192 } 193 194 int 195 get_peer_port(int sock) 196 { 197 return get_sock_port(sock, 0); 198 } 199 200 int 201 get_local_port(int sock) 202 { 203 return get_sock_port(sock, 1); 204 } 205
