1 /* $OpenBSD: canohost.c,v 1.73 2016/03/07 19:02:43 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 <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 * 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 /* Get IP address of client. */ 48 addrlen = sizeof(addr); 49 memset(&addr, 0, sizeof(addr)); 50 51 if (remote) { 52 if (getpeername(sock, (struct sockaddr *)&addr, &addrlen) != 0) 53 return NULL; 54 } else { 55 if (getsockname(sock, (struct sockaddr *)&addr, &addrlen) != 0) 56 return NULL; 57 } 58 59 switch (addr.ss_family) { 60 case AF_INET: 61 case AF_INET6: 62 /* Get the address in ascii. */ 63 if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop, 64 sizeof(ntop), NULL, 0, flags)) != 0) { 65 error("%s: getnameinfo %d failed: %s", __func__, 66 flags, ssh_gai_strerror(r)); 67 return NULL; 68 } 69 return xstrdup(ntop); 70 case AF_UNIX: 71 /* Get the Unix domain socket path. */ 72 return xstrdup(((struct sockaddr_un *)&addr)->sun_path); 73 default: 74 /* We can't look up remote Unix domain sockets. */ 75 return NULL; 76 } 77 } 78 79 char * 80 get_peer_ipaddr(int sock) 81 { 82 char *p; 83 84 if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL) 85 return p; 86 return xstrdup("UNKNOWN"); 87 } 88 89 char * 90 get_local_ipaddr(int sock) 91 { 92 char *p; 93 94 if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL) 95 return p; 96 return xstrdup("UNKNOWN"); 97 } 98 99 char * 100 get_local_name(int fd) 101 { 102 char *host, myname[NI_MAXHOST]; 103 104 /* Assume we were passed a socket */ 105 if ((host = get_socket_address(fd, 0, NI_NAMEREQD)) != NULL) 106 return host; 107 108 /* Handle the case where we were passed a pipe */ 109 if (gethostname(myname, sizeof(myname)) == -1) { 110 verbose("%s: gethostname: %s", __func__, strerror(errno)); 111 host = xstrdup("UNKNOWN"); 112 } else { 113 host = xstrdup(myname); 114 } 115 116 return host; 117 } 118 119 /* Returns the local/remote port for the socket. */ 120 121 static int 122 get_sock_port(int sock, int local) 123 { 124 struct sockaddr_storage from; 125 socklen_t fromlen; 126 char strport[NI_MAXSERV]; 127 int r; 128 129 /* Get IP address of client. */ 130 fromlen = sizeof(from); 131 memset(&from, 0, sizeof(from)); 132 if (local) { 133 if (getsockname(sock, (struct sockaddr *)&from, &fromlen) < 0) { 134 error("getsockname failed: %.100s", strerror(errno)); 135 return 0; 136 } 137 } else { 138 if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) { 139 debug("getpeername failed: %.100s", strerror(errno)); 140 return -1; 141 } 142 } 143 144 /* Non-inet sockets don't have a port number. */ 145 if (from.ss_family != AF_INET && from.ss_family != AF_INET6) 146 return 0; 147 148 /* Return port number. */ 149 if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0, 150 strport, sizeof(strport), NI_NUMERICSERV)) != 0) 151 fatal("%s: getnameinfo NI_NUMERICSERV failed: %s", __func__, 152 ssh_gai_strerror(r)); 153 return atoi(strport); 154 } 155 156 int 157 get_peer_port(int sock) 158 { 159 return get_sock_port(sock, 0); 160 } 161 162 int 163 get_local_port(int sock) 164 { 165 return get_sock_port(sock, 1); 166 } 167