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-rw-r--r--canohost.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/canohost.c b/canohost.c
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+/* $OpenBSD: canohost.c,v 1.75 2020/10/18 11:32:01 djm 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 <sys/un.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.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
+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(a4, 0, sizeof(*a4));
+
+ a4->sin_family = AF_INET;
+ *len = sizeof(*a4);
+ memcpy(&a4->sin_addr, &inaddr, sizeof(inaddr));
+ a4->sin_port = port;
+}
+
+/*
+ * 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);
+ }
+
+ switch (addr.ss_family) {
+ case AF_INET:
+ case AF_INET6:
+ /* Get the address in ascii. */
+ if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop,
+ sizeof(ntop), NULL, 0, flags)) != 0) {
+ error_f("getnameinfo %d failed: %s",
+ flags, ssh_gai_strerror(r));
+ return NULL;
+ }
+ return xstrdup(ntop);
+ case AF_UNIX:
+ /* Get the Unix domain socket path. */
+ return xstrdup(((struct sockaddr_un *)&addr)->sun_path);
+ default:
+ /* We can't look up remote Unix domain sockets. */
+ return NULL;
+ }
+}
+
+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 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_f("gethostname: %s", strerror(errno));
+ host = xstrdup("UNKNOWN");
+ } else {
+ host = xstrdup(myname);
+ }
+
+ return host;
+}
+
+/* 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) == -1) {
+ error("getsockname failed: %.100s", strerror(errno));
+ return 0;
+ }
+ } else {
+ if (getpeername(sock, (struct sockaddr *)&from, &fromlen) == -1) {
+ debug("getpeername failed: %.100s", strerror(errno));
+ return -1;
+ }
+ }
+
+ /* Work around Linux IPv6 weirdness */
+ if (from.ss_family == AF_INET6)
+ fromlen = sizeof(struct sockaddr_in6);
+
+ /* Non-inet sockets don't have a port number. */
+ if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
+ return 0;
+
+ /* Return port number. */
+ if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0,
+ strport, sizeof(strport), NI_NUMERICSERV)) != 0)
+ fatal_f("getnameinfo NI_NUMERICSERV failed: %s",
+ ssh_gai_strerror(r));
+ return atoi(strport);
+}
+
+int
+get_peer_port(int sock)
+{
+ return get_sock_port(sock, 0);
+}
+
+int
+get_local_port(int sock)
+{
+ return get_sock_port(sock, 1);
+}