diff options
Diffstat (limited to 'canohost.c')
| -rw-r--r-- | canohost.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/canohost.c b/canohost.c new file mode 100644 index 0000000..a810da0 --- /dev/null +++ b/canohost.c @@ -0,0 +1,204 @@ +/* $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); +} |