freebsd-dev/contrib/tcp_wrappers/tli.c

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/*
* tli_host() determines the type of transport (connected, connectionless),
* the transport address of a client host, and the transport address of a
* server endpoint. In addition, it provides methods to map a transport
* address to a printable host name or address. Socket address results are
* in static memory; tli structures are allocated from the heap.
*
* The result from the hostname lookup method is STRING_PARANOID when a host
* pretends to have someone elses name, or when a host name is available but
* could not be verified.
*
* Diagnostics are reported through syslog(3).
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*
* $FreeBSD$
*/
#ifndef lint
static char sccsid[] = "@(#) tli.c 1.15 97/03/21 19:27:25";
#endif
#ifdef TLI
/* System libraries. */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stream.h>
#include <sys/stat.h>
#include <sys/mkdev.h>
#include <sys/tiuser.h>
#include <sys/timod.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#include <errno.h>
#include <netconfig.h>
#include <netdir.h>
#include <string.h>
extern char *nc_sperror();
extern int errno;
extern char *sys_errlist[];
extern int sys_nerr;
extern int t_errno;
extern char *t_errlist[];
extern int t_nerr;
/* Local stuff. */
#include "tcpd.h"
/* Forward declarations. */
static void tli_endpoints();
static struct netconfig *tli_transport();
static void tli_hostname();
static void tli_hostaddr();
static void tli_cleanup();
static char *tli_error();
static void tli_sink();
/* tli_host - look up endpoint addresses and install conversion methods */
void tli_host(request)
struct request_info *request;
{
#ifdef INET6
static struct sockaddr_storage client;
static struct sockaddr_storage server;
#else
static struct sockaddr_in client;
static struct sockaddr_in server;
#endif
/*
* If we discover that we are using an IP transport, pretend we never
* were here. Otherwise, use the transport-independent method and stick
* to generic network addresses. XXX hard-coded protocol family name.
*/
tli_endpoints(request);
#ifdef INET6
if ((request->config = tli_transport(request->fd)) != 0
&& (STR_EQ(request->config->nc_protofmly, "inet") ||
STR_EQ(request->config->nc_protofmly, "inet6"))) {
#else
if ((request->config = tli_transport(request->fd)) != 0
&& STR_EQ(request->config->nc_protofmly, "inet")) {
#endif
if (request->client->unit != 0) {
#ifdef INET6
client = *(struct sockaddr_storage *) request->client->unit->addr.buf;
request->client->sin = (struct sockaddr *) &client;
#else
client = *(struct sockaddr_in *) request->client->unit->addr.buf;
request->client->sin = &client;
#endif
}
if (request->server->unit != 0) {
#ifdef INET6
server = *(struct sockaddr_storage *) request->server->unit->addr.buf;
request->server->sin = (struct sockaddr *) &server;
#else
server = *(struct sockaddr_in *) request->server->unit->addr.buf;
request->server->sin = &server;
#endif
}
tli_cleanup(request);
sock_methods(request);
} else {
request->hostname = tli_hostname;
request->hostaddr = tli_hostaddr;
request->cleanup = tli_cleanup;
}
}
/* tli_cleanup - cleanup some dynamically-allocated data structures */
static void tli_cleanup(request)
struct request_info *request;
{
if (request->config != 0)
freenetconfigent(request->config);
if (request->client->unit != 0)
t_free((char *) request->client->unit, T_UNITDATA);
if (request->server->unit != 0)
t_free((char *) request->server->unit, T_UNITDATA);
}
/* tli_endpoints - determine TLI client and server endpoint information */
static void tli_endpoints(request)
struct request_info *request;
{
struct t_unitdata *server;
struct t_unitdata *client;
int fd = request->fd;
int flags;
/*
* Determine the client endpoint address. With unconnected services, peek
* at the sender address of the pending protocol data unit without
* popping it off the receive queue. This trick works because only the
* address member of the unitdata structure has been allocated.
*
* Beware of successful returns with zero-length netbufs (for example,
* Solaris 2.3 with ticlts transport). The netdir(3) routines can't
* handle that. Assume connection-less transport when TI_GETPEERNAME
* produces no usable result, even when t_rcvudata() is unable to figure
* out the peer address. Better to hang than to loop.
*/
if ((client = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ADDR)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
return;
}
if (ioctl(fd, TI_GETPEERNAME, &client->addr) < 0 || client->addr.len == 0) {
request->sink = tli_sink;
if (t_rcvudata(fd, client, &flags) < 0 || client->addr.len == 0) {
tcpd_warn("can't get client address: %s", tli_error());
t_free((void *) client, T_UNITDATA);
return;
}
}
request->client->unit = client;
/*
* Look up the server endpoint address. This can be used for filtering on
* server address or name, or to look up the client user.
*/
if ((server = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ADDR)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
return;
}
if (ioctl(fd, TI_GETMYNAME, &server->addr) < 0) {
tcpd_warn("TI_GETMYNAME: %m");
t_free((void *) server, T_UNITDATA);
return;
}
request->server->unit = server;
}
/* tli_transport - find out TLI transport type */
static struct netconfig *tli_transport(fd)
int fd;
{
struct stat from_client;
struct stat from_config;
void *handlep;
struct netconfig *config;
/*
* Assuming that the network device is a clone device, we must compare
* the major device number of stdin to the minor device number of the
* devices listed in the netconfig table.
*/
if (fstat(fd, &from_client) != 0) {
tcpd_warn("fstat(fd %d): %m", fd);
return (0);
}
if ((handlep = setnetconfig()) == 0) {
tcpd_warn("setnetconfig: %m");
return (0);
}
while (config = getnetconfig(handlep)) {
if (stat(config->nc_device, &from_config) == 0) {
#ifdef NO_CLONE_DEVICE
/*
* If the network devices are not cloned (as is the case for
* Solaris 8 Beta), we must compare the major device numbers.
*/
if (major(from_config.st_rdev) == major(from_client.st_rdev))
#else
if (minor(from_config.st_rdev) == major(from_client.st_rdev))
#endif
break;
}
}
if (config == 0) {
tcpd_warn("unable to identify transport protocol");
return (0);
}
/*
* Something else may clobber our getnetconfig() result, so we'd better
* acquire our private copy.
*/
if ((config = getnetconfigent(config->nc_netid)) == 0) {
tcpd_warn("getnetconfigent(%s): %s", config->nc_netid, nc_sperror());
return (0);
}
return (config);
}
/* tli_hostaddr - map TLI transport address to printable address */
static void tli_hostaddr(host)
struct host_info *host;
{
struct request_info *request = host->request;
struct netconfig *config = request->config;
struct t_unitdata *unit = host->unit;
char *uaddr;
if (config != 0 && unit != 0
&& (uaddr = taddr2uaddr(config, &unit->addr)) != 0) {
STRN_CPY(host->addr, uaddr, sizeof(host->addr));
free(uaddr);
}
}
/* tli_hostname - map TLI transport address to hostname */
static void tli_hostname(host)
struct host_info *host;
{
struct request_info *request = host->request;
struct netconfig *config = request->config;
struct t_unitdata *unit = host->unit;
struct nd_hostservlist *servlist;
if (config != 0 && unit != 0
&& netdir_getbyaddr(config, &servlist, &unit->addr) == ND_OK) {
struct nd_hostserv *service = servlist->h_hostservs;
struct nd_addrlist *addr_list;
int found = 0;
if (netdir_getbyname(config, service, &addr_list) != ND_OK) {
/*
* Unable to verify that the name matches the address. This may
* be a transient problem or a botched name server setup. We
* decide to play safe.
*/
tcpd_warn("can't verify hostname: netdir_getbyname(%.*s) failed",
STRING_LENGTH, service->h_host);
} else {
/*
* Look up the host address in the address list we just got. The
* comparison is done on the textual representation, because the
* transport address is an opaque structure that may have holes
* with uninitialized garbage. This approach obviously loses when
* the address does not have a textual representation.
*/
char *uaddr = eval_hostaddr(host);
char *ua;
int i;
for (i = 0; found == 0 && i < addr_list->n_cnt; i++) {
if ((ua = taddr2uaddr(config, &(addr_list->n_addrs[i]))) != 0) {
found = !strcmp(ua, uaddr);
free(ua);
}
}
netdir_free((void *) addr_list, ND_ADDRLIST);
/*
* When the host name does not map to the initial address, assume
* someone has compromised a name server. More likely someone
* botched it, but that could be dangerous, too.
*/
if (found == 0)
tcpd_warn("host name/address mismatch: %s != %.*s",
host->addr, STRING_LENGTH, service->h_host);
}
STRN_CPY(host->name, found ? service->h_host : paranoid,
sizeof(host->name));
netdir_free((void *) servlist, ND_HOSTSERVLIST);
}
}
/* tli_error - convert tli error number to text */
static char *tli_error()
{
static char buf[40];
if (t_errno != TSYSERR) {
if (t_errno < 0 || t_errno >= t_nerr) {
sprintf(buf, "Unknown TLI error %d", t_errno);
return (buf);
} else {
return (t_errlist[t_errno]);
}
} else {
if (errno < 0 || errno >= sys_nerr) {
sprintf(buf, "Unknown UNIX error %d", errno);
return (buf);
} else {
return (sys_errlist[errno]);
}
}
}
/* tli_sink - absorb unreceived datagram */
static void tli_sink(fd)
int fd;
{
struct t_unitdata *unit;
int flags;
/*
* Something went wrong. Absorb the datagram to keep inetd from looping.
* Allocate storage for address, control and data. If that fails, sleep
* for a couple of seconds in an attempt to keep inetd from looping too
* fast.
*/
if ((unit = (struct t_unitdata *) t_alloc(fd, T_UNITDATA, T_ALL)) == 0) {
tcpd_warn("t_alloc: %s", tli_error());
sleep(5);
} else {
(void) t_rcvudata(fd, unit, &flags);
t_free((void *) unit, T_UNITDATA);
}
}
#endif /* TLI */