upstream commit

refactor canohost.c: move functions that cache results closer
 to the places that use them (authn and session code). After this, no state is
 cached in canohost.c

feedback and ok markus@

Upstream-ID: 5f2e4df88d4803fc8ec59ec53629105e23ce625e

21 files changed, 372 insertions, 373 deletions

diff --git a/auth-options.c b/auth-options.c
index edbaf80b..b399b91e 100644
--- a/auth-options.c
+++ b/auth-options.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-options.c,v 1.70 2015/12/10 17:08:40 mmcc Exp $ */
+/* $OpenBSD: auth-options.c,v 1.71 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
@@ -29,6 +29,7 @@
 #include "ssherr.h"
 #include "log.h"
 #include "canohost.h"
+#include "packet.h"
 #include "sshbuf.h"
 #include "misc.h"
 #include "channels.h"
@@ -120,6 +121,7 @@ match_flag(const char *opt, int allow_negate, char **optsp, const char *msg)
 int
 auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
 {
+	struct ssh *ssh = active_state;		/* XXX */
 	const char *cp;
 	int i, r;
 
@@ -273,9 +275,9 @@ auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
 		}
 		cp = "from=\"";
 		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
-			const char *remote_ip = get_remote_ipaddr();
-			const char *remote_host = get_canonical_hostname(
-			    options.use_dns);
+			const char *remote_ip = ssh_remote_ipaddr(ssh);
+			const char *remote_host = auth_get_canonical_hostname(
+			    ssh, options.use_dns);
 			char *patterns = xmalloc(strlen(opts) + 1);
 
 			opts += strlen(cp);
@@ -457,6 +459,7 @@ parse_option_list(struct sshbuf *oblob, struct passwd *pw,
     char **cert_forced_command,
     int *cert_source_address_done)
 {
+	struct ssh *ssh = active_state;		/* XXX */
 	char *command, *allowed;
 	const char *remote_ip;
 	char *name = NULL;
@@ -530,7 +533,7 @@ parse_option_list(struct sshbuf *oblob, struct passwd *pw,
 					free(allowed);
 					goto out;
 				}
-				remote_ip = get_remote_ipaddr();
+				remote_ip = ssh_remote_ipaddr(ssh);
 				result = addr_match_cidr_list(remote_ip,
 				    allowed);
 				free(allowed);
diff --git a/auth-rh-rsa.c b/auth-rh-rsa.c
index 2e20396e..057335ba 100644
--- a/auth-rh-rsa.c
+++ b/auth-rh-rsa.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-rh-rsa.c,v 1.44 2014/07/15 15:54:14 millert Exp $ */
+/* $OpenBSD: auth-rh-rsa.c,v 1.45 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
@@ -42,8 +42,8 @@
 extern ServerOptions options;
 
 int
-auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost,
-    Key *client_host_key)
+auth_rhosts_rsa_key_allowed(struct passwd *pw, const char *cuser,
+    const char *chost, Key *client_host_key)
 {
 	HostStatus host_status;
 
@@ -68,7 +68,8 @@ auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost,
 int
 auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key)
 {
-	char *chost;
+	struct ssh *ssh = active_state; /* XXX */
+	const char *chost;
 	struct passwd *pw = authctxt->pw;
 
 	debug("Trying rhosts with RSA host authentication for client user %.100s",
@@ -78,7 +79,7 @@ auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key)
 	    client_host_key->rsa == NULL)
 		return 0;
 
-	chost = (char *)get_canonical_hostname(options.use_dns);
+	chost = auth_get_canonical_hostname(ssh, options.use_dns);
 	debug("Rhosts RSA authentication: canonical host %.900s", chost);
 
 	if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) {
diff --git a/auth-rhosts.c b/auth-rhosts.c
index ee9e827a..0ef34471 100644
--- a/auth-rhosts.c
+++ b/auth-rhosts.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-rhosts.c,v 1.46 2014/12/23 22:42:48 djm Exp $ */
+/* $OpenBSD: auth-rhosts.c,v 1.47 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
@@ -30,14 +30,15 @@
 #include <unistd.h>
 
 #include "packet.h"
-#include "buffer.h"
 #include "uidswap.h"
 #include "pathnames.h"
 #include "log.h"
 #include "misc.h"
+#include "buffer.h" /* XXX */
+#include "key.h" /* XXX */
 #include "servconf.h"
 #include "canohost.h"
-#include "key.h"
+#include "sshkey.h"
 #include "hostfile.h"
 #include "auth.h"
 
@@ -189,10 +190,11 @@ check_rhosts_file(const char *filename, const char *hostname,
 int
 auth_rhosts(struct passwd *pw, const char *client_user)
 {
+	struct ssh *ssh = active_state;	/* XXX */
 	const char *hostname, *ipaddr;
 
-	hostname = get_canonical_hostname(options.use_dns);
-	ipaddr = get_remote_ipaddr();
+	hostname = auth_get_canonical_hostname(ssh, options.use_dns);
+	ipaddr = ssh_remote_ipaddr(ssh);
 	return auth_rhosts2(pw, client_user, hostname, ipaddr);
 }
 
diff --git a/auth.c b/auth.c
index 214c2c70..aae0593e 100644
--- a/auth.c
+++ b/auth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.c,v 1.113 2015/08/21 03:42:19 djm Exp $ */
+/* $OpenBSD: auth.c,v 1.114 2016/03/07 19:02:43 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -27,6 +27,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/socket.h>
 
 #include <netinet/in.h>
 
@@ -50,6 +51,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <limits.h>
+#include <netdb.h>
 
 #include "xmalloc.h"
 #include "match.h"
@@ -97,6 +99,7 @@ int auth_debug_init;
 int
 allowed_user(struct passwd * pw)
 {
+	struct ssh *ssh = active_state; /* XXX */
 	struct stat st;
 	const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
 	u_int i;
@@ -182,8 +185,8 @@ allowed_user(struct passwd * pw)
 
 	if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
 	    options.num_deny_groups > 0 || options.num_allow_groups > 0) {
-		hostname = get_canonical_hostname(options.use_dns);
-		ipaddr = get_remote_ipaddr();
+		hostname = auth_get_canonical_hostname(ssh, options.use_dns);
+		ipaddr = ssh_remote_ipaddr(ssh);
 	}
 
 	/* Return false if user is listed in DenyUsers */
@@ -274,6 +277,7 @@ void
 auth_log(Authctxt *authctxt, int authenticated, int partial,
     const char *method, const char *submethod)
 {
+	struct ssh *ssh = active_state; /* XXX */
 	void (*authlog) (const char *fmt,...) = verbose;
 	char *authmsg;
 
@@ -300,8 +304,8 @@ auth_log(Authctxt *authctxt, int authenticated, int partial,
 	    submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod,
 	    authctxt->valid ? "" : "invalid user ",
 	    authctxt->user,
-	    get_remote_ipaddr(),
-	    get_remote_port(),
+	    ssh_remote_ipaddr(ssh),
+	    ssh_remote_port(ssh),
 	    compat20 ? "ssh2" : "ssh1",
 	    authctxt->info != NULL ? ": " : "",
 	    authctxt->info != NULL ? authctxt->info : "");
@@ -331,12 +335,14 @@ auth_log(Authctxt *authctxt, int authenticated, int partial,
 void
 auth_maxtries_exceeded(Authctxt *authctxt)
 {
+	struct ssh *ssh = active_state; /* XXX */
+
 	error("maximum authentication attempts exceeded for "
 	    "%s%.100s from %.200s port %d %s",
 	    authctxt->valid ? "" : "invalid user ",
 	    authctxt->user,
-	    get_remote_ipaddr(),
-	    get_remote_port(),
+	    ssh_remote_ipaddr(ssh),
+	    ssh_remote_port(ssh),
 	    compat20 ? "ssh2" : "ssh1");
 	packet_disconnect("Too many authentication failures");
 	/* NOTREACHED */
@@ -348,6 +354,8 @@ auth_maxtries_exceeded(Authctxt *authctxt)
 int
 auth_root_allowed(const char *method)
 {
+	struct ssh *ssh = active_state; /* XXX */
+
 	switch (options.permit_root_login) {
 	case PERMIT_YES:
 		return 1;
@@ -364,7 +372,8 @@ auth_root_allowed(const char *method)
 		}
 		break;
 	}
-	logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
+	logit("ROOT LOGIN REFUSED FROM %.200s port %d",
+	    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
 	return 0;
 }
 
@@ -604,6 +613,7 @@ auth_openprincipals(const char *file, struct passwd *pw, int strict_modes)
 struct passwd *
 getpwnamallow(const char *user)
 {
+	struct ssh *ssh = active_state; /* XXX */
 #ifdef HAVE_LOGIN_CAP
 	extern login_cap_t *lc;
 #ifdef BSD_AUTH
@@ -639,8 +649,8 @@ getpwnamallow(const char *user)
 	}
 #endif
 	if (pw == NULL) {
-		logit("Invalid user %.100s from %.100s",
-		    user, get_remote_ipaddr());
+		logit("Invalid user %.100s from %.100s port %d",
+		    user, ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
 #ifdef CUSTOM_FAILED_LOGIN
 		record_failed_login(user,
 		    get_canonical_hostname(options.use_dns), "ssh");
@@ -773,3 +783,118 @@ fakepw(void)
 
 	return (&fake);
 }
+
+/*
+ * Returns the remote DNS hostname as a string. The returned string must not
+ * be freed. NB. this will usually trigger a DNS query the first time it is
+ * called.
+ * This function does additional checks on the hostname to mitigate some
+ * attacks on legacy rhosts-style authentication.
+ * XXX is RhostsRSAAuthentication vulnerable to these?
+ * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?)
+ */
+
+static char *
+remote_hostname(struct ssh *ssh)
+{
+	struct sockaddr_storage from;
+	socklen_t fromlen;
+	struct addrinfo hints, *ai, *aitop;
+	char name[NI_MAXHOST], ntop2[NI_MAXHOST];
+	const char *ntop = ssh_remote_ipaddr(ssh);
+
+	/* Get IP address of client. */
+	fromlen = sizeof(from);
+	memset(&from, 0, sizeof(from));
+	if (getpeername(ssh_packet_get_connection_in(ssh),
+	    (struct sockaddr *)&from, &fromlen) < 0) {
+		debug("getpeername failed: %.100s", strerror(errno));
+		return strdup(ntop);
+	}
+
+	ipv64_normalise_mapped(&from, &fromlen);
+	if (from.ss_family == AF_INET6)
+		fromlen = sizeof(struct sockaddr_in6);
+
+	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 strdup(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 strdup(ntop);
+	}
+
+	/* Names are stored 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 strdup(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 == NULL) {
+		/* 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 strdup(ntop);
+	}
+	return strdup(name);
+}
+
+/*
+ * 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 *
+auth_get_canonical_hostname(struct ssh *ssh, int use_dns)
+{
+	static char *dnsname;
+
+	if (!use_dns)
+		return ssh_remote_ipaddr(ssh);
+	else if (dnsname != NULL)
+		return dnsname;
+	else {
+		dnsname = remote_hostname(ssh);
+		return dnsname;
+	}
+}
diff --git a/auth.h b/auth.h
index 2160154f..038b5929 100644
--- a/auth.h
+++ b/auth.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.h,v 1.86 2015/12/04 16:41:28 markus Exp $ */
+/* $OpenBSD: auth.h,v 1.87 2016/03/07 19:02:43 djm Exp $ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -197,6 +197,8 @@ FILE	*auth_openkeyfile(const char *, struct passwd *, int);
 FILE	*auth_openprincipals(const char *, struct passwd *, int);
 int	 auth_key_is_revoked(Key *);
 
+const char	*auth_get_canonical_hostname(struct ssh *, int);
+
 HostStatus
 check_key_in_hostfiles(struct passwd *, Key *, const char *,
     const char *, const char *);
diff --git a/auth2-hostbased.c b/auth2-hostbased.c
index e2327cf7..1b3c3b20 100644
--- a/auth2-hostbased.c
+++ b/auth2-hostbased.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-hostbased.c,v 1.25 2015/05/04 06:10:48 djm Exp $ */
+/* $OpenBSD: auth2-hostbased.c,v 1.26 2016/03/07 19:02:43 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -160,6 +160,7 @@ int
 hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
     Key *key)
 {
+	struct ssh *ssh = active_state; /* XXX */
 	const char *resolvedname, *ipaddr, *lookup, *reason;
 	HostStatus host_status;
 	int len;
@@ -168,8 +169,8 @@ hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
 	if (auth_key_is_revoked(key))
 		return 0;
 
-	resolvedname = get_canonical_hostname(options.use_dns);
-	ipaddr = get_remote_ipaddr();
+	resolvedname = auth_get_canonical_hostname(ssh, options.use_dns);
+	ipaddr = ssh_remote_ipaddr(ssh);
 
 	debug2("%s: chost %s resolvedname %s ipaddr %s", __func__,
 	    chost, resolvedname, ipaddr);
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);
 }
diff --git a/canohost.h b/canohost.h
index 4c8636f4..26d62855 100644
--- a/canohost.h
+++ b/canohost.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: canohost.h,v 1.11 2009/05/27 06:31:25 andreas Exp $ */
+/* $OpenBSD: canohost.h,v 1.12 2016/03/07 19:02:43 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -12,18 +12,15 @@
  * called by a name other than "ssh" or "Secure Shell".
  */
 
-const char	*get_canonical_hostname(int);
-const char	*get_remote_ipaddr(void);
-const char	*get_remote_name_or_ip(u_int, int);
+#ifndef _CANOHOST_H
+#define _CANOHOST_H
 
 char		*get_peer_ipaddr(int);
 int		 get_peer_port(int);
 char		*get_local_ipaddr(int);
 char		*get_local_name(int);
+int		get_local_port(int);
 
-int		 get_remote_port(void);
-int		 get_local_port(void);
-int		 get_sock_port(int, int);
-void		 clear_cached_addr(void);
+#endif /* _CANOHOST_H */
 
 void		 ipv64_normalise_mapped(struct sockaddr_storage *, socklen_t *);
diff --git a/channels.c b/channels.c
index c9d2015e..7ee1f98d 100644
--- a/channels.c
+++ b/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.349 2016/02/05 13:28:19 naddy Exp $ */
+/* $OpenBSD: channels.c,v 1.350 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
@@ -1416,7 +1416,7 @@ port_open_helper(Channel *c, char *rtype)
 {
 	char buf[1024];
 	char *local_ipaddr = get_local_ipaddr(c->sock);
-	int local_port = c->sock == -1 ? 65536 : get_sock_port(c->sock, 1);
+	int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
 	char *remote_ipaddr = get_peer_ipaddr(c->sock);
 	int remote_port = get_peer_port(c->sock);
 
@@ -2935,7 +2935,7 @@ channel_setup_fwd_listener_tcpip(int type, struct Forward *fwd,
 		if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
 		    allocated_listen_port != NULL &&
 		    *allocated_listen_port == 0) {
-			*allocated_listen_port = get_sock_port(sock, 1);
+			*allocated_listen_port = get_local_port(sock);
 			debug("Allocated listen port %d",
 			    *allocated_listen_port);
 		}
diff --git a/monitor.c b/monitor.c
index ac7dd309..6b780e48 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.157 2016/02/15 23:32:37 djm Exp $ */
+/* $OpenBSD: monitor.c,v 1.158 2016/03/07 19:02:43 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -1469,6 +1469,7 @@ mm_answer_keyverify(int sock, Buffer *m)
 static void
 mm_record_login(Session *s, struct passwd *pw)
 {
+	struct ssh *ssh = active_state;	/* XXX */
 	socklen_t fromlen;
 	struct sockaddr_storage from;
 
@@ -1490,7 +1491,7 @@ mm_record_login(Session *s, struct passwd *pw)
 	}
 	/* Record that there was a login on that tty from the remote host. */
 	record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
-	    get_remote_name_or_ip(utmp_len, options.use_dns),
+	    session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
 	    (struct sockaddr *)&from, fromlen);
 }
 
diff --git a/monitor_wrap.c b/monitor_wrap.c
index c5db6df4..55200490 100644
--- a/monitor_wrap.c
+++ b/monitor_wrap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor_wrap.c,v 1.87 2016/01/14 16:17:40 markus Exp $ */
+/* $OpenBSD: monitor_wrap.c,v 1.88 2016/03/07 19:02:43 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -378,15 +378,15 @@ mm_user_key_allowed(struct passwd *pw, Key *key, int pubkey_auth_attempt)
 }
 
 int
-mm_hostbased_key_allowed(struct passwd *pw, char *user, char *host,
+mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host,
     Key *key)
 {
 	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
 }
 
 int
-mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, char *user,
-    char *host, Key *key)
+mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, const char *user,
+    const char *host, Key *key)
 {
 	int ret;
 
@@ -397,8 +397,8 @@ mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, char *user,
 }
 
 int
-mm_key_allowed(enum mm_keytype type, char *user, char *host, Key *key,
-    int pubkey_auth_attempt)
+mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
+    Key *key, int pubkey_auth_attempt)
 {
 	Buffer m;
 	u_char *blob;
diff --git a/monitor_wrap.h b/monitor_wrap.h
index eb820aee..9fd02b30 100644
--- a/monitor_wrap.h
+++ b/monitor_wrap.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor_wrap.h,v 1.29 2015/12/04 16:41:28 markus Exp $ */
+/* $OpenBSD: monitor_wrap.h,v 1.30 2016/03/07 19:02:43 djm Exp $ */