diff options
Diffstat (limited to 'crypto/openssh/canohost.c')
-rw-r--r-- | crypto/openssh/canohost.c | 417 |
1 files changed, 0 insertions, 417 deletions
diff --git a/crypto/openssh/canohost.c b/crypto/openssh/canohost.c deleted file mode 100644 index 2345cc3..0000000 --- a/crypto/openssh/canohost.c +++ /dev/null @@ -1,417 +0,0 @@ -/* $OpenBSD: canohost.c,v 1.61 2006/08/03 03:34:41 deraadt Exp $ */ -/* - * Author: Tatu Ylonen <ylo@cs.hut.fi> - * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland - * All rights reserved - * Functions for returning the canonical host name of the remote site. - * - * As far as I am concerned, the code I have written for this software - * can be used freely for any purpose. Any derived versions of this - * software must be clearly marked as such, and if the derived work is - * incompatible with the protocol description in the RFC file, it must be - * called by a name other than "ssh" or "Secure Shell". - */ - -#include "includes.h" - -#include <sys/types.h> -#include <sys/socket.h> - -#include <netinet/in.h> -#include <arpa/inet.h> - -#include <ctype.h> -#include <errno.h> -#include <netdb.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <stdarg.h> - -#include "xmalloc.h" -#include "packet.h" -#include "log.h" -#include "canohost.h" - -static void check_ip_options(int, char *); - -/* - * Return the canonical name of the host at the other end of the socket. The - * caller should free the returned string with xfree. - */ - -static char * -get_remote_hostname(int sock, int use_dns) -{ - struct sockaddr_storage from; - int i; - socklen_t fromlen; - struct addrinfo hints, *ai, *aitop; - char name[NI_MAXHOST], ntop[NI_MAXHOST], ntop2[NI_MAXHOST]; - - /* Get IP address of client. */ - fromlen = sizeof(from); - memset(&from, 0, sizeof(from)); - if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) { - debug("getpeername failed: %.100s", strerror(errno)); - cleanup_exit(255); - } - - if (from.ss_family == AF_INET) - check_ip_options(sock, ntop); - - ipv64_normalise_mapped(&from, &fromlen); - - if (from.ss_family == AF_INET6) - fromlen = sizeof(struct sockaddr_in6); - - if (getnameinfo((struct sockaddr *)&from, fromlen, ntop, sizeof(ntop), - NULL, 0, NI_NUMERICHOST) != 0) - fatal("get_remote_hostname: getnameinfo NI_NUMERICHOST failed"); - - if (!use_dns) - return xstrdup(ntop); - - debug3("Trying to reverse map address %.100s.", ntop); - /* Map the IP address to a host name. */ - if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), - NULL, 0, NI_NAMEREQD) != 0) { - /* Host name not found. Use ip address. */ - return xstrdup(ntop); - } - - /* - * if reverse lookup result looks like a numeric hostname, - * someone is trying to trick us by PTR record like following: - * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 - */ - memset(&hints, 0, sizeof(hints)); - hints.ai_socktype = SOCK_DGRAM; /*dummy*/ - hints.ai_flags = AI_NUMERICHOST; - if (getaddrinfo(name, "0", &hints, &ai) == 0) { - logit("Nasty PTR record \"%s\" is set up for %s, ignoring", - name, ntop); - freeaddrinfo(ai); - return xstrdup(ntop); - } - - /* - * Convert it to all lowercase (which is expected by the rest - * of this software). - */ - for (i = 0; name[i]; i++) - if (isupper(name[i])) - name[i] = (char)tolower(name[i]); - /* - * Map it back to an IP address and check that the given - * address actually is an address of this host. This is - * necessary because anyone with access to a name server can - * define arbitrary names for an IP address. Mapping from - * name to IP address can be trusted better (but can still be - * fooled if the intruder has access to the name server of - * the domain). - */ - memset(&hints, 0, sizeof(hints)); - hints.ai_family = from.ss_family; - hints.ai_socktype = SOCK_STREAM; - if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { - logit("reverse mapping checking getaddrinfo for %.700s " - "[%s] failed - POSSIBLE BREAK-IN ATTEMPT!", name, ntop); - return xstrdup(ntop); - } - /* Look for the address from the list of addresses. */ - for (ai = aitop; ai; ai = ai->ai_next) { - if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2, - sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 && - (strcmp(ntop, ntop2) == 0)) - break; - } - freeaddrinfo(aitop); - /* If we reached the end of the list, the address was not there. */ - if (!ai) { - /* Address not found for the host name. */ - logit("Address %.100s maps to %.600s, but this does not " - "map back to the address - POSSIBLE BREAK-IN ATTEMPT!", - ntop, name); - return xstrdup(ntop); - } - return xstrdup(name); -} - -/* - * If IP options are supported, make sure there are none (log and - * disconnect them if any are found). Basically we are worried about - * source routing; it can be used to pretend you are somebody - * (ip-address) you are not. That itself may be "almost acceptable" - * under certain circumstances, but rhosts autentication is useless - * if source routing is accepted. Notice also that if we just dropped - * source routing here, the other side could use IP spoofing to do - * rest of the interaction and could still bypass security. So we - * exit here if we detect any IP options. - */ -/* IPv4 only */ -static void -check_ip_options(int sock, char *ipaddr) -{ -#ifdef IP_OPTIONS - u_char options[200]; - char text[sizeof(options) * 3 + 1]; - socklen_t option_size; - u_int i; - int ipproto; - struct protoent *ip; - - if ((ip = getprotobyname("ip")) != NULL) - ipproto = ip->p_proto; - else - ipproto = IPPROTO_IP; - option_size = sizeof(options); - if (getsockopt(sock, ipproto, IP_OPTIONS, options, - &option_size) >= 0 && option_size != 0) { - text[0] = '\0'; - for (i = 0; i < option_size; i++) - snprintf(text + i*3, sizeof(text) - i*3, - " %2.2x", options[i]); - fatal("Connection from %.100s with IP options:%.800s", - ipaddr, text); - } -#endif /* IP_OPTIONS */ -} - -void -ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len) -{ - struct sockaddr_in6 *a6 = (struct sockaddr_in6 *)addr; - struct sockaddr_in *a4 = (struct sockaddr_in *)addr; - struct in_addr inaddr; - u_int16_t port; - - if (addr->ss_family != AF_INET6 || - !IN6_IS_ADDR_V4MAPPED(&a6->sin6_addr)) - return; - - debug3("Normalising mapped IPv4 in IPv6 address"); - - memcpy(&inaddr, ((char *)&a6->sin6_addr) + 12, sizeof(inaddr)); - port = a6->sin6_port; - - memset(addr, 0, sizeof(*a4)); - - a4->sin_family = AF_INET; - *len = sizeof(*a4); - memcpy(&a4->sin_addr, &inaddr, sizeof(inaddr)); - a4->sin_port = port; -} - -/* - * Return the canonical name of the host in the other side of the current - * connection. The host name is cached, so it is efficient to call this - * several times. - */ - -const char * -get_canonical_hostname(int use_dns) -{ - char *host; - static char *canonical_host_name = NULL; - static char *remote_ip = NULL; - - /* Check if we have previously retrieved name with same option. */ - if (use_dns && canonical_host_name != NULL) - return canonical_host_name; - if (!use_dns && remote_ip != NULL) - return remote_ip; - - /* Get the real hostname if socket; otherwise return UNKNOWN. */ - if (packet_connection_is_on_socket()) - host = get_remote_hostname(packet_get_connection_in(), use_dns); - else - host = "UNKNOWN"; - - if (use_dns) - canonical_host_name = host; - else - remote_ip = host; - return host; -} - -/* - * Returns the local/remote IP-address/hostname of socket as a string. - * The returned string must be freed. - */ -static char * -get_socket_address(int sock, int remote, int flags) -{ - struct sockaddr_storage addr; - socklen_t addrlen; - char ntop[NI_MAXHOST]; - int r; - - /* Get IP address of client. */ - addrlen = sizeof(addr); - memset(&addr, 0, sizeof(addr)); - - if (remote) { - if (getpeername(sock, (struct sockaddr *)&addr, &addrlen) - < 0) - return NULL; - } else { - if (getsockname(sock, (struct sockaddr *)&addr, &addrlen) - < 0) - return NULL; - } - - /* Work around Linux IPv6 weirdness */ - if (addr.ss_family == AF_INET6) - addrlen = sizeof(struct sockaddr_in6); - - ipv64_normalise_mapped(&addr, &addrlen); - - /* Get the address in ascii. */ - if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop, - sizeof(ntop), NULL, 0, flags)) != 0) { - error("get_socket_address: getnameinfo %d failed: %s", flags, - r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r)); - return NULL; - } - return xstrdup(ntop); -} - -char * -get_peer_ipaddr(int sock) -{ - char *p; - - if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL) - return p; - return xstrdup("UNKNOWN"); -} - -char * -get_local_ipaddr(int sock) -{ - char *p; - - if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL) - return p; - return xstrdup("UNKNOWN"); -} - -char * -get_local_name(int sock) -{ - return get_socket_address(sock, 0, NI_NAMEREQD); -} - -/* - * Returns the IP-address of the remote host as a string. The returned - * string must not be freed. - */ - -const char * -get_remote_ipaddr(void) -{ - static char *canonical_host_ip = NULL; - - /* Check whether we have cached the ipaddr. */ - if (canonical_host_ip == NULL) { - if (packet_connection_is_on_socket()) { - canonical_host_ip = - get_peer_ipaddr(packet_get_connection_in()); - if (canonical_host_ip == NULL) - cleanup_exit(255); - } else { - /* If not on socket, return UNKNOWN. */ - canonical_host_ip = xstrdup("UNKNOWN"); - } - } - return canonical_host_ip; -} - -const char * -get_remote_name_or_ip(u_int utmp_len, int use_dns) -{ - static const char *remote = ""; - if (utmp_len > 0) - remote = get_canonical_hostname(use_dns); - if (utmp_len == 0 || strlen(remote) > utmp_len) - remote = get_remote_ipaddr(); - return remote; -} - -/* Returns the local/remote port for the socket. */ - -static int -get_sock_port(int sock, int local) -{ - struct sockaddr_storage from; - socklen_t fromlen; - char strport[NI_MAXSERV]; - int r; - - /* Get IP address of client. */ - fromlen = sizeof(from); - memset(&from, 0, sizeof(from)); - if (local) { - if (getsockname(sock, (struct sockaddr *)&from, &fromlen) < 0) { - error("getsockname failed: %.100s", strerror(errno)); - return 0; - } - } else { - if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) { - debug("getpeername failed: %.100s", strerror(errno)); - return -1; - } - } - - /* Work around Linux IPv6 weirdness */ - if (from.ss_family == AF_INET6) - fromlen = sizeof(struct sockaddr_in6); - - /* Return port number. */ - if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0, - strport, sizeof(strport), NI_NUMERICSERV)) != 0) - fatal("get_sock_port: getnameinfo NI_NUMERICSERV failed: %s", - r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r)); - return atoi(strport); -} - -/* Returns remote/local port number for the current connection. */ - -static int -get_port(int local) -{ - /* - * If the connection is not a socket, return 65535. This is - * intentionally chosen to be an unprivileged port number. - */ - if (!packet_connection_is_on_socket()) - return 65535; - - /* Get socket and return the port number. */ - return get_sock_port(packet_get_connection_in(), local); -} - -int -get_peer_port(int sock) -{ - return get_sock_port(sock, 0); -} - -int -get_remote_port(void) -{ - static int port = -1; - - /* Cache to avoid getpeername() on a dead connection */ - if (port == -1) - port = get_port(0); - - return port; -} - -int -get_local_port(void) -{ - return get_port(1); -} |