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-rw-r--r--canohost.c262
1 files changed, 10 insertions, 252 deletions
diff --git a/canohost.c b/canohost.c
index 223964ea..f71a0856 100644
--- a/canohost.c
+++ b/canohost.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: canohost.c,v 1.72 2015/03/01 15:44:40 millert Exp $ */
+/* $OpenBSD: canohost.c,v 1.73 2016/03/07 19:02:43 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -35,147 +35,6 @@
#include "canohost.h"
#include "misc.h"
-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.
- */
-
-static char *
-get_remote_hostname(int sock, int use_dns)
-{
- struct sockaddr_storage from;
- 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, NULL, &hints, &ai) == 0) {
- logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
- name, ntop);
- freeaddrinfo(ai);
- return xstrdup(ntop);
- }
-
- /* Names are stores in lowercase. */
- lowercase(name);
-
- /*
- * 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, 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)
{
@@ -202,38 +61,6 @@ ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len)
}
/*
- * 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.
*/
@@ -250,12 +77,10 @@ get_socket_address(int sock, int remote, int flags)
memset(&addr, 0, sizeof(addr));
if (remote) {
- if (getpeername(sock, (struct sockaddr *)&addr, &addrlen)
- < 0)
+ if (getpeername(sock, (struct sockaddr *)&addr, &addrlen) != 0)
return NULL;
} else {
- if (getsockname(sock, (struct sockaddr *)&addr, &addrlen)
- < 0)
+ if (getsockname(sock, (struct sockaddr *)&addr, &addrlen) != 0)
return NULL;
}
@@ -271,7 +96,7 @@ get_socket_address(int sock, int remote, int flags)
/* 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",
+ error("%s: getnameinfo %d failed: %s", __func__,
flags, ssh_gai_strerror(r));
return NULL;
}
@@ -316,7 +141,8 @@ get_local_name(int fd)
/* Handle the case where we were passed a pipe */
if (gethostname(myname, sizeof(myname)) == -1) {
- verbose("get_local_name: gethostname: %s", strerror(errno));
+ verbose("%s: gethostname: %s", __func__, strerror(errno));
+ host = xstrdup("UNKNOWN");
} else {
host = xstrdup(myname);
}
@@ -324,51 +150,9 @@ get_local_name(int fd)
return host;
}
-void
-clear_cached_addr(void)
-{
- free(canonical_host_ip);
- canonical_host_ip = NULL;
- cached_port = -1;
-}
-
-/*
- * Returns the IP-address of the remote host as a string. The returned
- * string must not be freed.
- */
-
-const char *
-get_remote_ipaddr(void)
-{
- /* 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. */
-int
+static int
get_sock_port(int sock, int local)
{
struct sockaddr_storage from;
@@ -402,27 +186,11 @@ get_sock_port(int sock, int local)
/* 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",
+ fatal("%s: getnameinfo NI_NUMERICSERV failed: %s", __func__,
ssh_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)
{
@@ -430,17 +198,7 @@ get_peer_port(int sock)
}
int
-get_remote_port(void)
-{
- /* Cache to avoid getpeername() on a dead connection */
- if (cached_port == -1)
- cached_port = get_port(0);
-
- return cached_port;
-}
-
-int
-get_local_port(void)
+get_local_port(int sock)
{
- return get_port(1);
+ return get_sock_port(sock, 1);
}