diff options
Diffstat (limited to 'canohost.c')
-rw-r--r-- | canohost.c | 184 |
1 files changed, 96 insertions, 88 deletions
@@ -14,7 +14,7 @@ */ #include "includes.h" -RCSID("$Id: canohost.c,v 1.6 1999/12/18 09:57:40 damien Exp $"); +RCSID("$Id: canohost.c,v 1.7 2000/01/14 04:45:48 damien Exp $"); #include "packet.h" #include "xmalloc.h" @@ -28,10 +28,12 @@ RCSID("$Id: canohost.c,v 1.6 1999/12/18 09:57:40 damien Exp $"); char * get_remote_hostname(int socket) { - struct sockaddr_in from; - int fromlen, i; - struct hostent *hp; + struct sockaddr_storage from; + int i; + socklen_t fromlen; + struct addrinfo hints, *ai, *aitop; char name[MAXHOSTNAMELEN]; + char ntop[NI_MAXHOST], ntop2[NI_MAXHOST]; /* Get IP address of client. */ fromlen = sizeof(from); @@ -40,20 +42,15 @@ get_remote_hostname(int socket) debug("getpeername failed: %.100s", strerror(errno)); fatal_cleanup(); } - /* Map the IP address to a host name. */ - hp = gethostbyaddr((char *) &from.sin_addr, sizeof(struct in_addr), - from.sin_family); - if (hp) { - /* Got host name, find canonic host name. */ - if (strchr(hp->h_name, '.') != 0) - strlcpy(name, hp->h_name, sizeof(name)); - else if (hp->h_aliases != 0 - && hp->h_aliases[0] != 0 - && strchr(hp->h_aliases[0], '.') != 0) - strlcpy(name, hp->h_aliases[0], sizeof(name)); - else - strlcpy(name, hp->h_name, sizeof(name)); + if (getnameinfo((struct sockaddr *)&from, fromlen, ntop, sizeof(ntop), + NULL, 0, NI_NUMERICHOST) != 0) + fatal("get_remote_hostname: getnameinfo NI_NUMERICHOST failed"); + /* Map the IP address to a host name. */ + if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), + NULL, 0, NI_NAMEREQD) == 0) { + /* Got host name. */ + name[sizeof(name) - 1] = '\0'; /* * Convert it to all lowercase (which is expected by the rest * of this software). @@ -71,32 +68,34 @@ get_remote_hostname(int socket) * fooled if the intruder has access to the name server of * the domain). */ - hp = gethostbyname(name); - if (!hp) { - log("reverse mapping checking gethostbyname for %.700s failed - POSSIBLE BREAKIN ATTEMPT!", name); - strlcpy(name, inet_ntoa(from.sin_addr), sizeof name); + memset(&hints, 0, sizeof(hints)); + hints.ai_family = from.ss_family; + hints.ai_socktype = SOCK_STREAM; + if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { + log("reverse mapping checking getaddrinfo for %.700s failed - POSSIBLE BREAKIN ATTEMPT!", name); + strlcpy(name, ntop, sizeof name); goto check_ip_options; } /* Look for the address from the list of addresses. */ - for (i = 0; hp->h_addr_list[i]; i++) - if (memcmp(hp->h_addr_list[i], &from.sin_addr, sizeof(from.sin_addr)) - == 0) - break; - /* - * If we reached the end of the list, the address was not - * there. - */ - if (!hp->h_addr_list[i]) { + 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. */ log("Address %.100s maps to %.600s, but this does not map back to the address - POSSIBLE BREAKIN ATTEMPT!", - inet_ntoa(from.sin_addr), name); - strlcpy(name, inet_ntoa(from.sin_addr), sizeof name); + ntop, name); + strlcpy(name, ntop, sizeof name); goto check_ip_options; } /* Address was found for the host name. We accept the host name. */ } else { /* Host name not found. Use ascii representation of the address. */ - strlcpy(name, inet_ntoa(from.sin_addr), sizeof name); + strlcpy(name, ntop, sizeof name); log("Could not reverse map address %.100s.", name); } @@ -113,10 +112,12 @@ check_ip_options: * rest of the interaction and could still bypass security. So we * exit here if we detect any IP options. */ - { + /* IP options -- IPv4 only */ + if (from.ss_family == AF_INET) { unsigned char options[200], *ucp; char text[1024], *cp; - int option_size, ipproto; + socklen_t option_size; + int ipproto; struct protoent *ip; if ((ip = getprotobyname("ip")) != NULL) @@ -125,47 +126,21 @@ check_ip_options: ipproto = IPPROTO_IP; option_size = sizeof(options); if (getsockopt(0, ipproto, IP_OPTIONS, (char *) options, - &option_size) >= 0 && option_size != 0) { + &option_size) >= 0 && option_size != 0) { cp = text; /* Note: "text" buffer must be at least 3x as big as options. */ for (ucp = options; option_size > 0; ucp++, option_size--, cp += 3) sprintf(cp, " %2.2x", *ucp); log("Connection from %.100s with IP options:%.800s", - inet_ntoa(from.sin_addr), text); + ntop, text); packet_disconnect("Connection from %.100s with IP options:%.800s", - inet_ntoa(from.sin_addr), text); + ntop, text); } } return xstrdup(name); } -static char *canonical_host_name = NULL; -static char *canonical_host_ip = NULL; - -/* Returns 1 if remote host is connected via socket, 0 if not. */ - -int -peer_connection_is_on_socket() -{ - struct sockaddr_in from; - int fromlen; - int in = packet_get_connection_in(); - int out = packet_get_connection_out(); - - /* filedescriptors in and out are the same, so it's a socket */ - if (in == out) - return 1; - fromlen = sizeof(from); - memset(&from, 0, sizeof(from)); - if (getpeername(in, (struct sockaddr *) & from, &fromlen) < 0) - return 0; - if (from.sin_family != AF_INET) - return 0; - - return 1; -} - /* * 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 @@ -175,12 +150,14 @@ peer_connection_is_on_socket() const char * get_canonical_hostname() { + static char *canonical_host_name = NULL; + /* Check if we have previously retrieved this same name. */ if (canonical_host_name != NULL) return canonical_host_name; /* Get the real hostname if socket; otherwise return UNKNOWN. */ - if (peer_connection_is_on_socket()) + if (packet_connection_is_on_socket()) canonical_host_name = get_remote_hostname(packet_get_connection_in()); else canonical_host_name = xstrdup("UNKNOWN"); @@ -190,21 +167,24 @@ get_canonical_hostname() /* * Returns the IP-address of the remote host as a string. The returned - * string need not be freed. + * string must not be freed. */ const char * get_remote_ipaddr() { - struct sockaddr_in from; - int fromlen, socket; + static char *canonical_host_ip = NULL; + struct sockaddr_storage from; + socklen_t fromlen; + int socket; + char ntop[NI_MAXHOST]; /* Check whether we have chached the name. */ if (canonical_host_ip != NULL) return canonical_host_ip; /* If not a socket, return UNKNOWN. */ - if (!peer_connection_is_on_socket()) { + if (!packet_connection_is_on_socket()) { canonical_host_ip = xstrdup("UNKNOWN"); return canonical_host_ip; } @@ -219,48 +199,76 @@ get_remote_ipaddr() fatal_cleanup(); } /* Get the IP address in ascii. */ - canonical_host_ip = xstrdup(inet_ntoa(from.sin_addr)); + if (getnameinfo((struct sockaddr *)&from, fromlen, ntop, sizeof(ntop), + NULL, 0, NI_NUMERICHOST) != 0) + fatal("get_remote_hostname: getnameinfo NI_NUMERICHOST failed"); + + canonical_host_ip = xstrdup(ntop); /* Return ip address string. */ return canonical_host_ip; } -/* Returns the port of the peer of the socket. */ +/* Returns the local/remote port for the socket. */ -int -get_peer_port(int sock) +int +get_sock_port(int sock, int local) { - struct sockaddr_in from; - int fromlen; + struct sockaddr_storage from; + socklen_t fromlen; + char strport[NI_MAXSERV]; /* 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)); - fatal_cleanup(); + 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)); + fatal_cleanup(); + } } /* Return port number. */ - return ntohs(from.sin_port); + if (getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0, + strport, sizeof(strport), NI_NUMERICSERV) != 0) + fatal("get_sock_port: getnameinfo NI_NUMERICSERV failed"); + return atoi(strport); } -/* Returns the port number of the remote host. */ +/* Returns remote/local port number for the current connection. */ int -get_remote_port() +get_port(int local) { - int socket; - /* * If the connection is not a socket, return 65535. This is * intentionally chosen to be an unprivileged port number. */ - if (!peer_connection_is_on_socket()) + if (!packet_connection_is_on_socket()) return 65535; - /* Get client socket. */ - socket = packet_get_connection_in(); + /* 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); +} - /* Get and return the peer port number. */ - return get_peer_port(socket); +int +get_remote_port() +{ + return get_port(0); +} + +int +get_local_port() +{ + return get_port(1); } |