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 * 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 * 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 * 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 * 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 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 162 get_peer_port(int sock) 163 { 164 return get_sock_port(sock, 0); 165 } 166 167 int 168 get_local_port(int sock) 169 { 170 return get_sock_port(sock, 1); 171 } 172