+/* $OpenBSD: canohost.c,v 1.66 2010/01/13 01:20:20 dtucker Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
*/
#include "includes.h"
-RCSID("$OpenBSD: canohost.c,v 1.26 2001/04/18 14:15:00 markus Exp $");
-#include "packet.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 <unistd.h>
+
#include "xmalloc.h"
+#include "packet.h"
#include "log.h"
#include "canohost.h"
+#include "misc.h"
-void check_ip_options(int socket, char *ipaddr);
+static void check_ip_options(int, char *);
+static char *canonical_host_ip = NULL;
+static int cached_port = -1;
/*
* Return the canonical name of the host at the other end of the socket. The
* caller should free the returned string with xfree.
*/
-char *
-get_remote_hostname(int socket, int reverse_mapping_check)
+static char *
+get_remote_hostname(int sock, int use_dns)
{
struct sockaddr_storage from;
int i;
/* Get IP address of client. */
fromlen = sizeof(from);
memset(&from, 0, sizeof(from));
- if (getpeername(socket, (struct sockaddr *) &from, &fromlen) < 0) {
+ if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) {
debug("getpeername failed: %.100s", strerror(errno));
- fatal_cleanup();
+ cleanup_exit(255);
}
-#ifdef IPV4_IN_IPV6
- if (from.ss_family == AF_INET6) {
- struct sockaddr_in6 *from6 = (struct sockaddr_in6 *)&from;
-
- /* Detect IPv4 in IPv6 mapped address and convert it to */
- /* plain (AF_INET) IPv4 address */
- if (IN6_IS_ADDR_V4MAPPED(&from6->sin6_addr)) {
- struct sockaddr_in *from4 = (struct sockaddr_in *)&from;
- struct in_addr addr;
- u_int16_t port;
- memcpy(&addr, ((char *)&from6->sin6_addr) + 12, sizeof(addr));
- port = from6->sin6_port;
+ if (from.ss_family == AF_INET)
+ check_ip_options(sock, ntop);
- memset(&from, 0, sizeof(from));
+ ipv64_normalise_mapped(&from, &fromlen);
- from4->sin_family = AF_INET;
- memcpy(&from4->sin_addr, &addr, sizeof(addr));
- from4->sin_port = port;
- }
- }
-#endif
- if (from.ss_family == AF_INET)
- check_ip_options(socket, ntop);
+ 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)
+ 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) {
+ NULL, 0, NI_NAMEREQD) != 0) {
/* Host name not found. Use ip address. */
- log("Could not reverse map address %.100s.", ntop);
return xstrdup(ntop);
}
- /* Got host name. */
- name[sizeof(name) - 1] = '\0';
+ /*
+ * 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, NULL, &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] = tolower(name[i]);
-
- if (!reverse_mapping_check)
- return xstrdup(name);
+ 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
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);
+ 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. */
/* 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!",
+ logit("Address %.100s maps to %.600s, but this does not "
+ "map back to the address - POSSIBLE BREAK-IN ATTEMPT!",
ntop, name);
return xstrdup(ntop);
}
* exit here if we detect any IP options.
*/
/* IPv4 only */
-void
-check_ip_options(int socket, char *ipaddr)
+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;
- int i, ipproto;
+ u_int i;
+ int ipproto;
struct protoent *ip;
if ((ip = getprotobyname("ip")) != NULL)
else
ipproto = IPPROTO_IP;
option_size = sizeof(options);
- if (getsockopt(socket, ipproto, IP_OPTIONS, (void *)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]);
- log("Connection from %.100s with IP options:%.800s",
- ipaddr, text);
- packet_disconnect("Connection from %.100s with IP options:%.800s",
+ 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;
}
/*
*/
const char *
-get_canonical_hostname(int reverse_mapping_check)
+get_canonical_hostname(int use_dns)
{
+ char *host;
static char *canonical_host_name = NULL;
- static int reverse_mapping_checked = 0;
+ static char *remote_ip = NULL;
/* Check if we have previously retrieved name with same option. */
- if (canonical_host_name != NULL) {
- if (reverse_mapping_checked != reverse_mapping_check)
- xfree(canonical_host_name);
- else
- return canonical_host_name;
- }
+ 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())
- canonical_host_name = get_remote_hostname(
- packet_get_connection_in(), reverse_mapping_check);
+ host = get_remote_hostname(packet_get_connection_in(), use_dns);
else
- canonical_host_name = xstrdup("UNKNOWN");
+ host = "UNKNOWN";
- reverse_mapping_checked = reverse_mapping_check;
- return canonical_host_name;
+ if (use_dns)
+ canonical_host_name = host;
+ else
+ remote_ip = host;
+ return host;
}
/*
- * Returns the remote IP-address of socket as a string. The returned
- * string must be freed.
+ * Returns the local/remote IP-address/hostname of socket as a string.
+ * The returned string must be freed.
*/
-char *
-get_socket_address(int socket, int remote, int flags)
+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(socket, (struct sockaddr *)&addr, &addrlen)
- < 0) {
- debug("get_socket_ipaddr: getpeername failed: %.100s",
- strerror(errno));
+ if (getpeername(sock, (struct sockaddr *)&addr, &addrlen)
+ < 0)
return NULL;
- }
} else {
- if (getsockname(socket, (struct sockaddr *)&addr, &addrlen)
- < 0) {
- debug("get_socket_ipaddr: getsockname failed: %.100s",
- strerror(errno));
+ 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 (getnameinfo((struct sockaddr *)&addr, addrlen, ntop, sizeof(ntop),
- NULL, 0, flags) != 0) {
- error("get_socket_ipaddr: getnameinfo %d failed", flags);
+ if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop,
+ sizeof(ntop), NULL, 0, flags)) != 0) {
+ error("get_socket_address: getnameinfo %d failed: %s", flags,
+ ssh_gai_strerror(r));
return NULL;
}
return xstrdup(ntop);
}
char *
-get_peer_ipaddr(int socket)
+get_peer_ipaddr(int sock)
{
- return get_socket_address(socket, 1, NI_NUMERICHOST);
+ char *p;
+
+ if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL)
+ return p;
+ return xstrdup("UNKNOWN");
}
char *
-get_local_ipaddr(int socket)
+get_local_ipaddr(int sock)
{
- return get_socket_address(socket, 0, NI_NUMERICHOST);
+ char *p;
+
+ if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL)
+ return p;
+ return xstrdup("UNKNOWN");
}
char *
-get_local_name(int socket)
+get_local_name(int fd)
+{
+ char *host, myname[NI_MAXHOST];
+
+ /* Assume we were passed a socket */
+ if ((host = get_socket_address(fd, 0, NI_NAMEREQD)) != NULL)
+ return host;
+
+ /* Handle the case where we were passed a pipe */
+ if (gethostname(myname, sizeof(myname)) == -1) {
+ verbose("get_local_name: gethostname: %s", strerror(errno));
+ } else {
+ host = xstrdup(myname);
+ }
+
+ return host;
+}
+
+void
+clear_cached_addr(void)
{
- return get_socket_address(socket, 0, NI_NAMEREQD);
+ if (canonical_host_ip != NULL) {
+ xfree(canonical_host_ip);
+ canonical_host_ip = NULL;
+ }
+ cached_port = -1;
}
/*
*/
const char *
-get_remote_ipaddr()
+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)
- fatal_cleanup();
+ cleanup_exit(255);
} else {
/* If not on socket, return UNKNOWN. */
canonical_host_ip = xstrdup("UNKNOWN");
}
const char *
-get_remote_name_or_ip(u_int utmp_len, int reverse_mapping_check)
+get_remote_name_or_ip(u_int utmp_len, int use_dns)
{
static const char *remote = "";
if (utmp_len > 0)
- remote = get_canonical_hostname(reverse_mapping_check);
+ remote = get_canonical_hostname(use_dns);
if (utmp_len == 0 || strlen(remote) > utmp_len)
remote = get_remote_ipaddr();
return remote;
struct sockaddr_storage from;
socklen_t fromlen;
char strport[NI_MAXSERV];
+ int r;
/* Get IP address of client. */
fromlen = sizeof(from);
return 0;
}
} else {
- if (getpeername(sock, (struct sockaddr *) & from, &fromlen) < 0) {
+ if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) {
debug("getpeername failed: %.100s", strerror(errno));
- fatal_cleanup();
+ return -1;
}
}
+
+ /* Work around Linux IPv6 weirdness */
+ if (from.ss_family == AF_INET6)
+ fromlen = sizeof(struct sockaddr_in6);
+
/* Return port number. */
- if (getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0,
- strport, sizeof(strport), NI_NUMERICSERV) != 0)
- fatal("get_sock_port: getnameinfo NI_NUMERICSERV failed");
+ if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0,
+ strport, sizeof(strport), NI_NUMERICSERV)) != 0)
+ fatal("get_sock_port: getnameinfo NI_NUMERICSERV failed: %s",
+ ssh_gai_strerror(r));
return atoi(strport);
}
/* Returns remote/local port number for the current connection. */
-int
+static int
get_port(int local)
{
/*
}
int
-get_remote_port()
+get_remote_port(void)
{
- return get_port(0);
+ /* Cache to avoid getpeername() on a dead connection */
+ if (cached_port == -1)
+ cached_port = get_port(0);
+
+ return cached_port;
}
int
-get_local_port()
+get_local_port(void)
{
return get_port(1);
}
andersk / openssh.git / blobdiff