1 #pragma ident "@(#)auth_time.c 1.4 92/11/10 SMI"
6 * This module contains the private function __rpc_get_time_offset()
7 * which will return the difference in seconds between the local system's
8 * notion of time and a remote server's notion of time. This must be
9 * possible without calling any functions that may invoke the name
10 * service. (netdir_getbyxxx, getXbyY, etc). The function is used in the
11 * synchronize call of the authdes code to synchronize clocks between
12 * NIS+ clients and their servers.
14 * Note to minimize the amount of duplicate code, portions of the
15 * synchronize() function were folded into this code, and the synchronize
16 * call becomes simply a wrapper around this function. Further, if this
17 * function is called with a timehost it *DOES* recurse to the name
18 * server so don't use it in that mode if you are doing name service code.
20 * Copyright (c) 1992 Sun Microsystems Inc.
21 * All rights reserved.
24 * When called a client handle to a RPCBIND process is created
25 * and destroyed. Two strings "netid" and "uaddr" are malloc'd
26 * and returned. The SIGALRM processing is modified only if
27 * needed to deal with TCP connections.
29 * NOTE: This code has had the crap beaten out it in order to convert
30 * it from TI-RPC back to TD-RPC for use on FreeBSD.
32 * $FreeBSD: src/lib/libc/rpc/auth_time.c,v 1.4 2000/01/27 23:06:35 jasone Exp $
33 * $DragonFly: src/lib/libc/rpc/auth_time.c,v 1.3 2005/01/31 22:29:38 dillon Exp $
35 #include "namespace.h"
42 #include <sys/signal.h>
43 #include <sys/errno.h>
44 #include <sys/socket.h>
45 #include <netinet/in.h>
46 #include <arpa/inet.h>
48 #include <rpc/rpc_com.h>
50 #include <rpcsvc/nis.h>
51 #include "un-namespace.h"
54 * FreeBSD currently uses RPC 4.0, which uses portmap rather than
55 * rpcbind. Consequently, we need to fake up these values here.
56 * Luckily, the RPCB_GETTIME procedure uses only base XDR data types
57 * so we don't need anything besides these magic numbers.
59 #define RPCBPROG (u_long)100000
60 #define RPCBVERS (u_long)3
61 #define RPCBPROC_GETTIME (u_long)6
64 #define msg(x) printf("ERROR: %s\n", x)
65 /* #define msg(x) syslog(LOG_ERR, "%s", x) */
70 static int saw_alarm = 0;
81 * The internet time server defines the epoch to be Jan 1, 1900
82 * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
83 * from internet time-service time, into UNIX time we subtract the
86 #define NYEARS (1970 - 1900)
87 #define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
91 * Stolen from rpc.nisd:
92 * Turn a 'universal address' into a struct sockaddr_in.
95 static int uaddr_to_sockaddr(uaddr, sin)
100 struct sockaddr_in *sin;
102 unsigned char p_bytes[2];
106 i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
107 &a[3], &a[4], &a[5]);
112 for (i = 0; i < 4; i++)
113 sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
115 p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
116 p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
118 sin->sin_family = AF_INET; /* always */
119 bcopy((char *)&p_bytes, (char *)&sin->sin_port, 2);
127 * Free the strings that were strduped into the eps structure.
136 for (i = 0; i < num; i++) {
147 * This function constructs a nis_server structure description for the
148 * indicated hostname.
150 * NOTE: There is a chance we may end up recursing here due to the
151 * fact that gethostbyname() could do an NIS search. Ideally, the
152 * NIS+ server will call __rpc_get_time_offset() with the nis_server
153 * structure already populated.
156 get_server(sin, host, srv, eps, maxep)
157 struct sockaddr_in *sin;
158 char *host; /* name of the time host */
159 nis_server *srv; /* nis_server struct to use. */
160 endpoint eps[]; /* array of endpoints */
161 int maxep; /* max array size */
166 struct hostent dummy;
169 if (host == NULL && sin == NULL)
173 he = gethostbyname(host);
178 ptr[0] = (char *)&sin->sin_addr.s_addr;
180 dummy.h_addr_list = ptr;
184 * This is lame. We go around once for TCP, then again
187 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
191 a = (struct in_addr *)he->h_addr_list[i];
192 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
193 eps[num_ep].uaddr = strdup(hname);
194 eps[num_ep].family = strdup("inet");
195 eps[num_ep].proto = strdup("tcp");
198 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
202 a = (struct in_addr *)he->h_addr_list[i];
203 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
204 eps[num_ep].uaddr = strdup(hname);
205 eps[num_ep].family = strdup("inet");
206 eps[num_ep].proto = strdup("udp");
209 srv->name = (nis_name) host;
210 srv->ep.ep_len = num_ep;
211 srv->ep.ep_val = eps;
212 srv->key_type = NIS_PK_NONE;
213 srv->pkey.n_bytes = NULL;
219 * __rpc_get_time_offset()
221 * This function uses a nis_server structure to contact the a remote
222 * machine (as named in that structure) and returns the offset in time
223 * between that machine and this one. This offset is returned in seconds
224 * and may be positive or negative.
226 * The first time through, a lot of fiddling is done with the netconfig
227 * stuff to find a suitable transport. The function is very aggressive
228 * about choosing UDP or at worst TCP if it can. This is because
229 * those transports support both the RCPBIND call and the internet
232 * Once through, *uaddr is set to the universal address of
233 * the machine and *netid is set to the local netid for the transport
234 * that uaddr goes with. On the second call, the netconfig stuff
235 * is skipped and the uaddr/netid pair are used to fetch the netconfig
236 * structure and to then contact the machine for the time.
238 * td = "server" - "client"
241 __rpc_get_time_offset(td, srv, thost, uaddr, netid)
242 struct timeval *td; /* Time difference */
243 nis_server *srv; /* NIS Server description */
244 char *thost; /* if no server, this is the timehost */
245 char **uaddr; /* known universal address */
246 struct sockaddr_in *netid; /* known network identifier */
248 CLIENT *clnt; /* Client handle */
249 endpoint *ep, /* useful endpoints */
250 *useep = NULL; /* endpoint of xp */
251 char *useua = NULL; /* uaddr of selected xp */
252 int epl, i; /* counters */
253 enum clnt_stat status; /* result of clnt_call */
254 u_long thetime, delta;
258 int udp_ep = -1, tcp_ep = -1;
260 char ut[64], ipuaddr[64];
263 void (*oldsig)() = NULL; /* old alarm handler */
264 struct sockaddr_in sin;
265 int s = RPC_ANYSOCK, len;
272 * First check to see if we need to find and address for this
275 if (*uaddr == NULL) {
276 if ((srv != NULL) && (thost != NULL)) {
277 msg("both timehost and srv pointer used!");
281 srv = get_server(netid, thost, &tsrv, teps, 32);
283 msg("unable to contruct server data.");
286 needfree = 1; /* need to free data in endpoints */
290 epl = srv->ep.ep_len;
292 /* Identify the TCP and UDP endpoints */
294 (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
295 if (strcasecmp(ep[i].proto, "udp") == 0)
297 if (strcasecmp(ep[i].proto, "tcp") == 0)
301 /* Check to see if it is UDP or TCP */
304 useua = ep[tcp_ep].uaddr;
306 } else if (udp_ep > -1) {
308 useua = ep[udp_ep].uaddr;
313 msg("no acceptable transport endpoints.");
315 free_eps(teps, tsrv.ep.ep_len);
321 * Create a sockaddr from the uaddr.
326 /* Fixup test for NIS+ */
327 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
328 sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
331 bzero((char *)&sin, sizeof(sin));
332 if (uaddr_to_sockaddr(useua, &sin)) {
333 msg("unable to translate uaddr to sockaddr.");
335 free_eps(teps, tsrv.ep.ep_len);
340 * Create the client handle to rpcbind. Note we always try
341 * version 3 since that is the earliest version that supports
342 * the RPCB_GETTIME call. Also it is the version that comes
343 * standard with SVR4. Since most everyone supports TCP/IP
344 * we could consider trying the rtime call first.
346 clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
348 msg("unable to create client handle to rpcbind.");
350 free_eps(teps, tsrv.ep.ep_len);
357 status = clnt_call(clnt, RPCBPROC_GETTIME, xdr_void, NULL,
358 xdr_u_long, (char *)&thetime, tv);
360 * The only error we check for is anything but success. In
361 * fact we could have seen PROGMISMATCH if talking to a 4.1
362 * machine (pmap v2) or TIMEDOUT if the net was busy.
364 if (status == RPC_SUCCESS)
369 /* Blow away possible stale CLNT handle. */
376 * Convert PMAP address into timeservice address
377 * We take advantage of the fact that we "know" what
378 * the universal address looks like for inet transports.
380 * We also know that the internet timeservice is always
381 * listening on port 37.
383 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
384 sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
386 if (uaddr_to_sockaddr(ut, &sin)) {
387 msg("cannot convert timeservice uaddr to sockaddr.");
391 s = _socket(AF_INET, type, 0);
393 msg("unable to open fd to network.");
398 * Now depending on whether or not we're talking to
399 * UDP we set a timeout or not.
401 if (type == SOCK_DGRAM) {
402 struct timeval timeout = { 20, 0 };
403 struct sockaddr_in from;
407 if (_sendto(s, &thetime, sizeof(thetime), 0,
408 (struct sockaddr *)&sin, sizeof(sin)) == -1) {
409 msg("udp : sendto failed.");
415 res = _select(_rpc_dtablesize(), &readfds,
416 (fd_set *)NULL, (fd_set *)NULL, &timeout);
417 } while (res < 0 && errno == EINTR);
421 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
422 (struct sockaddr *)&from, &len);
424 msg("recvfrom failed on udp transport.");
431 oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
432 saw_alarm = 0; /* global tracking the alarm */
433 alarm(20); /* only wait 20 seconds */
434 res = _connect(s, (struct sockaddr *)&sin, sizeof(sin));
436 msg("failed to connect to tcp endpoint.");
440 msg("alarm caught it, must be unreachable.");
443 res = _read(s, (char *)&thetime, sizeof(thetime));
444 if (res != sizeof(thetime)) {
446 msg("timed out TCP call.");
448 msg("wrong size of results returned");
460 thetime = ntohl(thetime);
461 thetime = thetime - TOFFSET; /* adjust to UNIX time */
466 gettimeofday(&tv, 0);
470 * clean up our allocated data structures.
473 if (s != RPC_ANYSOCK)
479 alarm(0); /* reset that alarm if its outstanding */
481 signal(SIGALRM, oldsig);
485 * note, don't free uaddr strings until after we've made a
490 *uaddr = strdup(useua);
492 /* Round to the nearest second */
493 tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
494 delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
496 td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
499 msg("unable to get the server's time.");
503 free_eps(teps, tsrv.ep.ep_len);