1/* #pragma ident "@(#)auth_time.c 1.4 92/11/10 SMI" */
2
3/*
4 * auth_time.c
5 *
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.
13 *
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.
19 *
20 * Copyright (c) 1992 Sun Microsystems Inc.
21 * All rights reserved.
22 *
23 * Side effects :
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.
28 *
29 * $FreeBSD: head/lib/libc/rpc/auth_time.c 90271 2002-02-05 23:43:43Z alfred $
30 */
31#include "namespace.h"
32#include <stdio.h>
33#include <syslog.h>
34#include <string.h>
35#include <stdlib.h>
36#include <unistd.h>
37#include <netdb.h>
38#include <sys/signal.h>
39#include <sys/errno.h>
40#include <sys/socket.h>
41#include <netinet/in.h>
42#include <arpa/inet.h>
43#include <rpc/rpc.h>
44#include <rpc/rpc_com.h>
45#include <rpc/rpcb_prot.h>
46#undef NIS
47#include <rpcsvc/nis.h>
48#include "un-namespace.h"
49
50#ifdef TESTING
51#define msg(x) printf("ERROR: %s\n", x)
52/* #define msg(x) syslog(LOG_ERR, "%s", x) */
53#else
54#define msg(x)
55#endif
56
57static int saw_alarm = 0;
58
59static void
60alarm_hndler(s)
61 int s;
62{
63 saw_alarm = 1;
64 return;
65}
66
67/*
68 * The internet time server defines the epoch to be Jan 1, 1900
69 * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
70 * from internet time-service time, into UNIX time we subtract the
71 * following offset :
72 */
73#define NYEARS (1970 - 1900)
74#define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
75
76
77/*
78 * Stolen from rpc.nisd:
79 * Turn a 'universal address' into a struct sockaddr_in.
80 * Bletch.
81 */
82static int uaddr_to_sockaddr(uaddr, sin)
83#ifdef foo
84 endpoint *endpt;
85#endif
86 char *uaddr;
87 struct sockaddr_in *sin;
88{
89 unsigned char p_bytes[2];
90 int i;
91 unsigned long a[6];
92
93 i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
94 &a[3], &a[4], &a[5]);
95
96 if (i < 6)
97 return(1);
98
99 for (i = 0; i < 4; i++)
100 sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
101
102 p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
103 p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
104
105 sin->sin_family = AF_INET; /* always */
106 bcopy((char *)&p_bytes, (char *)&sin->sin_port, 2);
107
108 return (0);
109}
110
111/*
112 * free_eps()
113 *
114 * Free the strings that were strduped into the eps structure.
115 */
116static void
117free_eps(eps, num)
118 endpoint eps[];
119 int num;
120{
121 int i;
122
123 for (i = 0; i < num; i++) {
124 free(eps[i].uaddr);
125 free(eps[i].proto);
126 free(eps[i].family);
127 }
128 return;
129}
130
131/*
132 * get_server()
133 *
134 * This function constructs a nis_server structure description for the
135 * indicated hostname.
136 *
137 * NOTE: There is a chance we may end up recursing here due to the
138 * fact that gethostbyname() could do an NIS search. Ideally, the
139 * NIS+ server will call __rpc_get_time_offset() with the nis_server
140 * structure already populated.
141 */
142static nis_server *
143get_server(sin, host, srv, eps, maxep)
144 struct sockaddr_in *sin;
145 char *host; /* name of the time host */
146 nis_server *srv; /* nis_server struct to use. */
147 endpoint eps[]; /* array of endpoints */
148 int maxep; /* max array size */
149{
150 char hname[256];
151 int num_ep = 0, i;
152 struct hostent *he;
153 struct hostent dummy;
154 char *ptr[2];
155
156 if (host == NULL && sin == NULL)
157 return (NULL);
158
159 if (sin == NULL) {
160 he = gethostbyname(host);
161 if (he == NULL)
162 return(NULL);
163 } else {
164 he = &dummy;
165 ptr[0] = (char *)&sin->sin_addr.s_addr;
166 ptr[1] = NULL;
167 dummy.h_addr_list = ptr;
168 }
169
170 /*
171 * This is lame. We go around once for TCP, then again
172 * for UDP.
173 */
174 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
175 i++, num_ep++) {
176 struct in_addr *a;
177
178 a = (struct in_addr *)he->h_addr_list[i];
179 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
180 eps[num_ep].uaddr = strdup(hname);
181 eps[num_ep].family = strdup("inet");
182 eps[num_ep].proto = strdup("tcp");
183 }
184
185 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
186 i++, num_ep++) {
187 struct in_addr *a;
188
189 a = (struct in_addr *)he->h_addr_list[i];
190 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
191 eps[num_ep].uaddr = strdup(hname);
192 eps[num_ep].family = strdup("inet");
193 eps[num_ep].proto = strdup("udp");
194 }
195
196 srv->name = (nis_name) host;
197 srv->ep.ep_len = num_ep;
198 srv->ep.ep_val = eps;
199 srv->key_type = NIS_PK_NONE;
200 srv->pkey.n_bytes = NULL;
201 srv->pkey.n_len = 0;
202 return (srv);
203}
204
205/*
206 * __rpc_get_time_offset()
207 *
208 * This function uses a nis_server structure to contact the a remote
209 * machine (as named in that structure) and returns the offset in time
210 * between that machine and this one. This offset is returned in seconds
211 * and may be positive or negative.
212 *
213 * The first time through, a lot of fiddling is done with the netconfig
214 * stuff to find a suitable transport. The function is very aggressive
215 * about choosing UDP or at worst TCP if it can. This is because
216 * those transports support both the RCPBIND call and the internet
217 * time service.
218 *
219 * Once through, *uaddr is set to the universal address of
220 * the machine and *netid is set to the local netid for the transport
221 * that uaddr goes with. On the second call, the netconfig stuff
222 * is skipped and the uaddr/netid pair are used to fetch the netconfig
223 * structure and to then contact the machine for the time.
224 *
225 * td = "server" - "client"
226 */
227int
228__rpc_get_time_offset(td, srv, thost, uaddr, netid)
229 struct timeval *td; /* Time difference */
230 nis_server *srv; /* NIS Server description */
231 char *thost; /* if no server, this is the timehost */
232 char **uaddr; /* known universal address */
233 struct sockaddr_in *netid; /* known network identifier */
234{
235 CLIENT *clnt; /* Client handle */
236 endpoint *ep, /* useful endpoints */
237 *useep = NULL; /* endpoint of xp */
238 char *useua = NULL; /* uaddr of selected xp */
239 int epl, i; /* counters */
240 enum clnt_stat status; /* result of clnt_call */
241 u_long thetime, delta;
242 int needfree = 0;
243 struct timeval tv;
244 int time_valid;
245 int udp_ep = -1, tcp_ep = -1;
246 int a1, a2, a3, a4;
247 char ut[64], ipuaddr[64];
248 endpoint teps[32];
249 nis_server tsrv;
250 void (*oldsig)() = NULL; /* old alarm handler */
251 struct sockaddr_in sin;
252 int s = RPC_ANYSOCK, len;
253 int type = 0;
254
255 td->tv_sec = 0;
256 td->tv_usec = 0;
257
258 /*
259 * First check to see if we need to find and address for this
260 * server.
261 */
262 if (*uaddr == NULL) {
263 if ((srv != NULL) && (thost != NULL)) {
264 msg("both timehost and srv pointer used!");
265 return (0);
266 }
267 if (! srv) {
268 srv = get_server(netid, thost, &tsrv, teps, 32);
269 if (srv == NULL) {
270 msg("unable to contruct server data.");
271 return (0);
272 }
273 needfree = 1; /* need to free data in endpoints */
274 }
275
276 ep = srv->ep.ep_val;
277 epl = srv->ep.ep_len;
278
279 /* Identify the TCP and UDP endpoints */
280 for (i = 0;
281 (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
282 if (strcasecmp(ep[i].proto, "udp") == 0)
283 udp_ep = i;
284 if (strcasecmp(ep[i].proto, "tcp") == 0)
285 tcp_ep = i;
286 }
287
288 /* Check to see if it is UDP or TCP */
289 if (tcp_ep > -1) {
290 useep = &ep[tcp_ep];
291 useua = ep[tcp_ep].uaddr;
292 type = SOCK_STREAM;
293 } else if (udp_ep > -1) {
294 useep = &ep[udp_ep];
295 useua = ep[udp_ep].uaddr;
296 type = SOCK_DGRAM;
297 }
298
299 if (useep == NULL) {
300 msg("no acceptable transport endpoints.");
301 if (needfree)
302 free_eps(teps, tsrv.ep.ep_len);
303 return (0);
304 }
305 }
306
307 /*
308 * Create a sockaddr from the uaddr.
309 */
310 if (*uaddr != NULL)
311 useua = *uaddr;
312
313 /* Fixup test for NIS+ */
314 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
315 sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
316 useua = &ipuaddr[0];
317
318 bzero((char *)&sin, sizeof(sin));
319 if (uaddr_to_sockaddr(useua, &sin)) {
320 msg("unable to translate uaddr to sockaddr.");
321 if (needfree)
322 free_eps(teps, tsrv.ep.ep_len);
323 return (0);
324 }
325
326 /*
327 * Create the client handle to rpcbind. Note we always try
328 * version 3 since that is the earliest version that supports
329 * the RPCB_GETTIME call. Also it is the version that comes
330 * standard with SVR4. Since most everyone supports TCP/IP
331 * we could consider trying the rtime call first.
332 */
333 clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
334 if (clnt == NULL) {
335 msg("unable to create client handle to rpcbind.");
336 if (needfree)
337 free_eps(teps, tsrv.ep.ep_len);
338 return (0);
339 }
340
341 tv.tv_sec = 5;
342 tv.tv_usec = 0;
343 time_valid = 0;
344 status = clnt_call(clnt, RPCBPROC_GETTIME, xdr_void, NULL,
345 xdr_u_long, (char *)&thetime, tv);
346 /*
347 * The only error we check for is anything but success. In
348 * fact we could have seen PROGMISMATCH if talking to a 4.1
349 * machine (pmap v2) or TIMEDOUT if the net was busy.
350 */
351 if (status == RPC_SUCCESS)
352 time_valid = 1;
353 else {
354 int save;
355
356 /* Blow away possible stale CLNT handle. */
357 if (clnt != NULL) {
358 clnt_destroy(clnt);
359 clnt = NULL;
360 }
361
362 /*
363 * Convert PMAP address into timeservice address
364 * We take advantage of the fact that we "know" what
365 * the universal address looks like for inet transports.
366 *
367 * We also know that the internet timeservice is always
368 * listening on port 37.
369 */
370 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
371 sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
372
373 if (uaddr_to_sockaddr(ut, &sin)) {
374 msg("cannot convert timeservice uaddr to sockaddr.");
375 goto error;
376 }
377
378 s = _socket(AF_INET, type, 0);
379 if (s == -1) {
380 msg("unable to open fd to network.");
381 goto error;
382 }
383
384 /*
385 * Now depending on whether or not we're talking to
386 * UDP we set a timeout or not.
387 */
388 if (type == SOCK_DGRAM) {
389 struct timeval timeout = { 20, 0 };
390 struct sockaddr_in from;
391 fd_set readfds;
392 int res;
393
394 if (_sendto(s, &thetime, sizeof(thetime), 0,
395 (struct sockaddr *)&sin, sizeof(sin)) == -1) {
396 msg("udp : sendto failed.");
397 goto error;
398 }
399 do {
400 FD_ZERO(&readfds);
401 FD_SET(s, &readfds);
402 res = _select(_rpc_dtablesize(), &readfds,
403 (fd_set *)NULL, (fd_set *)NULL, &timeout);
404 } while (res < 0 && errno == EINTR);
405 if (res <= 0)
406 goto error;
407 len = sizeof(from);
408 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
409 (struct sockaddr *)&from, &len);
410 if (res == -1) {
411 msg("recvfrom failed on udp transport.");
412 goto error;
413 }
414 time_valid = 1;
415 } else {
416 int res;
417
418 oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
419 saw_alarm = 0; /* global tracking the alarm */
420 alarm(20); /* only wait 20 seconds */
421 res = _connect(s, (struct sockaddr *)&sin, sizeof(sin));
422 if (res == -1) {
423 msg("failed to connect to tcp endpoint.");
424 goto error;
425 }
426 if (saw_alarm) {
427 msg("alarm caught it, must be unreachable.");
428 goto error;
429 }
430 res = _read(s, (char *)&thetime, sizeof(thetime));
431 if (res != sizeof(thetime)) {
432 if (saw_alarm)
433 msg("timed out TCP call.");
434 else
435 msg("wrong size of results returned");
436
437 goto error;
438 }
439 time_valid = 1;
440 }
441 save = errno;
442 (void)_close(s);
443 errno = save;
444 s = RPC_ANYSOCK;
445
446 if (time_valid) {
447 thetime = ntohl(thetime);
448 thetime = thetime - TOFFSET; /* adjust to UNIX time */
449 } else
450 thetime = 0;
451 }
452
453 gettimeofday(&tv, 0);
454
455error:
456 /*
457 * clean up our allocated data structures.
458 */
459
460 if (s != RPC_ANYSOCK)
461 (void)_close(s);
462
463 if (clnt != NULL)
464 clnt_destroy(clnt);
465
466 alarm(0); /* reset that alarm if its outstanding */
467 if (oldsig) {
468 signal(SIGALRM, oldsig);
469 }
470
471 /*
472 * note, don't free uaddr strings until after we've made a
473 * copy of them.
474 */
475 if (time_valid) {
476 if (*uaddr == NULL)
477 *uaddr = strdup(useua);
478
479 /* Round to the nearest second */
480 tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
481 delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
482 tv.tv_sec - thetime;
483 td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
484 td->tv_usec = 0;
485 } else {
486 msg("unable to get the server's time.");
487 }
488
489 if (needfree)
490 free_eps(teps, tsrv.ep.ep_len);
491
492 return (time_valid);
493}
2
3/*
4 * auth_time.c
5 *
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.
13 *
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.
19 *
20 * Copyright (c) 1992 Sun Microsystems Inc.
21 * All rights reserved.
22 *
23 * Side effects :
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.
28 *
29 * $FreeBSD: head/lib/libc/rpc/auth_time.c 90271 2002-02-05 23:43:43Z alfred $
30 */
31#include "namespace.h"
32#include <stdio.h>
33#include <syslog.h>
34#include <string.h>
35#include <stdlib.h>
36#include <unistd.h>
37#include <netdb.h>
38#include <sys/signal.h>
39#include <sys/errno.h>
40#include <sys/socket.h>
41#include <netinet/in.h>
42#include <arpa/inet.h>
43#include <rpc/rpc.h>
44#include <rpc/rpc_com.h>
45#include <rpc/rpcb_prot.h>
46#undef NIS
47#include <rpcsvc/nis.h>
48#include "un-namespace.h"
49
50#ifdef TESTING
51#define msg(x) printf("ERROR: %s\n", x)
52/* #define msg(x) syslog(LOG_ERR, "%s", x) */
53#else
54#define msg(x)
55#endif
56
57static int saw_alarm = 0;
58
59static void
60alarm_hndler(s)
61 int s;
62{
63 saw_alarm = 1;
64 return;
65}
66
67/*
68 * The internet time server defines the epoch to be Jan 1, 1900
69 * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
70 * from internet time-service time, into UNIX time we subtract the
71 * following offset :
72 */
73#define NYEARS (1970 - 1900)
74#define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
75
76
77/*
78 * Stolen from rpc.nisd:
79 * Turn a 'universal address' into a struct sockaddr_in.
80 * Bletch.
81 */
82static int uaddr_to_sockaddr(uaddr, sin)
83#ifdef foo
84 endpoint *endpt;
85#endif
86 char *uaddr;
87 struct sockaddr_in *sin;
88{
89 unsigned char p_bytes[2];
90 int i;
91 unsigned long a[6];
92
93 i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
94 &a[3], &a[4], &a[5]);
95
96 if (i < 6)
97 return(1);
98
99 for (i = 0; i < 4; i++)
100 sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
101
102 p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
103 p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
104
105 sin->sin_family = AF_INET; /* always */
106 bcopy((char *)&p_bytes, (char *)&sin->sin_port, 2);
107
108 return (0);
109}
110
111/*
112 * free_eps()
113 *
114 * Free the strings that were strduped into the eps structure.
115 */
116static void
117free_eps(eps, num)
118 endpoint eps[];
119 int num;
120{
121 int i;
122
123 for (i = 0; i < num; i++) {
124 free(eps[i].uaddr);
125 free(eps[i].proto);
126 free(eps[i].family);
127 }
128 return;
129}
130
131/*
132 * get_server()
133 *
134 * This function constructs a nis_server structure description for the
135 * indicated hostname.
136 *
137 * NOTE: There is a chance we may end up recursing here due to the
138 * fact that gethostbyname() could do an NIS search. Ideally, the
139 * NIS+ server will call __rpc_get_time_offset() with the nis_server
140 * structure already populated.
141 */
142static nis_server *
143get_server(sin, host, srv, eps, maxep)
144 struct sockaddr_in *sin;
145 char *host; /* name of the time host */
146 nis_server *srv; /* nis_server struct to use. */
147 endpoint eps[]; /* array of endpoints */
148 int maxep; /* max array size */
149{
150 char hname[256];
151 int num_ep = 0, i;
152 struct hostent *he;
153 struct hostent dummy;
154 char *ptr[2];
155
156 if (host == NULL && sin == NULL)
157 return (NULL);
158
159 if (sin == NULL) {
160 he = gethostbyname(host);
161 if (he == NULL)
162 return(NULL);
163 } else {
164 he = &dummy;
165 ptr[0] = (char *)&sin->sin_addr.s_addr;
166 ptr[1] = NULL;
167 dummy.h_addr_list = ptr;
168 }
169
170 /*
171 * This is lame. We go around once for TCP, then again
172 * for UDP.
173 */
174 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
175 i++, num_ep++) {
176 struct in_addr *a;
177
178 a = (struct in_addr *)he->h_addr_list[i];
179 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
180 eps[num_ep].uaddr = strdup(hname);
181 eps[num_ep].family = strdup("inet");
182 eps[num_ep].proto = strdup("tcp");
183 }
184
185 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
186 i++, num_ep++) {
187 struct in_addr *a;
188
189 a = (struct in_addr *)he->h_addr_list[i];
190 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
191 eps[num_ep].uaddr = strdup(hname);
192 eps[num_ep].family = strdup("inet");
193 eps[num_ep].proto = strdup("udp");
194 }
195
196 srv->name = (nis_name) host;
197 srv->ep.ep_len = num_ep;
198 srv->ep.ep_val = eps;
199 srv->key_type = NIS_PK_NONE;
200 srv->pkey.n_bytes = NULL;
201 srv->pkey.n_len = 0;
202 return (srv);
203}
204
205/*
206 * __rpc_get_time_offset()
207 *
208 * This function uses a nis_server structure to contact the a remote
209 * machine (as named in that structure) and returns the offset in time
210 * between that machine and this one. This offset is returned in seconds
211 * and may be positive or negative.
212 *
213 * The first time through, a lot of fiddling is done with the netconfig
214 * stuff to find a suitable transport. The function is very aggressive
215 * about choosing UDP or at worst TCP if it can. This is because
216 * those transports support both the RCPBIND call and the internet
217 * time service.
218 *
219 * Once through, *uaddr is set to the universal address of
220 * the machine and *netid is set to the local netid for the transport
221 * that uaddr goes with. On the second call, the netconfig stuff
222 * is skipped and the uaddr/netid pair are used to fetch the netconfig
223 * structure and to then contact the machine for the time.
224 *
225 * td = "server" - "client"
226 */
227int
228__rpc_get_time_offset(td, srv, thost, uaddr, netid)
229 struct timeval *td; /* Time difference */
230 nis_server *srv; /* NIS Server description */
231 char *thost; /* if no server, this is the timehost */
232 char **uaddr; /* known universal address */
233 struct sockaddr_in *netid; /* known network identifier */
234{
235 CLIENT *clnt; /* Client handle */
236 endpoint *ep, /* useful endpoints */
237 *useep = NULL; /* endpoint of xp */
238 char *useua = NULL; /* uaddr of selected xp */
239 int epl, i; /* counters */
240 enum clnt_stat status; /* result of clnt_call */
241 u_long thetime, delta;
242 int needfree = 0;
243 struct timeval tv;
244 int time_valid;
245 int udp_ep = -1, tcp_ep = -1;
246 int a1, a2, a3, a4;
247 char ut[64], ipuaddr[64];
248 endpoint teps[32];
249 nis_server tsrv;
250 void (*oldsig)() = NULL; /* old alarm handler */
251 struct sockaddr_in sin;
252 int s = RPC_ANYSOCK, len;
253 int type = 0;
254
255 td->tv_sec = 0;
256 td->tv_usec = 0;
257
258 /*
259 * First check to see if we need to find and address for this
260 * server.
261 */
262 if (*uaddr == NULL) {
263 if ((srv != NULL) && (thost != NULL)) {
264 msg("both timehost and srv pointer used!");
265 return (0);
266 }
267 if (! srv) {
268 srv = get_server(netid, thost, &tsrv, teps, 32);
269 if (srv == NULL) {
270 msg("unable to contruct server data.");
271 return (0);
272 }
273 needfree = 1; /* need to free data in endpoints */
274 }
275
276 ep = srv->ep.ep_val;
277 epl = srv->ep.ep_len;
278
279 /* Identify the TCP and UDP endpoints */
280 for (i = 0;
281 (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
282 if (strcasecmp(ep[i].proto, "udp") == 0)
283 udp_ep = i;
284 if (strcasecmp(ep[i].proto, "tcp") == 0)
285 tcp_ep = i;
286 }
287
288 /* Check to see if it is UDP or TCP */
289 if (tcp_ep > -1) {
290 useep = &ep[tcp_ep];
291 useua = ep[tcp_ep].uaddr;
292 type = SOCK_STREAM;
293 } else if (udp_ep > -1) {
294 useep = &ep[udp_ep];
295 useua = ep[udp_ep].uaddr;
296 type = SOCK_DGRAM;
297 }
298
299 if (useep == NULL) {
300 msg("no acceptable transport endpoints.");
301 if (needfree)
302 free_eps(teps, tsrv.ep.ep_len);
303 return (0);
304 }
305 }
306
307 /*
308 * Create a sockaddr from the uaddr.
309 */
310 if (*uaddr != NULL)
311 useua = *uaddr;
312
313 /* Fixup test for NIS+ */
314 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
315 sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
316 useua = &ipuaddr[0];
317
318 bzero((char *)&sin, sizeof(sin));
319 if (uaddr_to_sockaddr(useua, &sin)) {
320 msg("unable to translate uaddr to sockaddr.");
321 if (needfree)
322 free_eps(teps, tsrv.ep.ep_len);
323 return (0);
324 }
325
326 /*
327 * Create the client handle to rpcbind. Note we always try
328 * version 3 since that is the earliest version that supports
329 * the RPCB_GETTIME call. Also it is the version that comes
330 * standard with SVR4. Since most everyone supports TCP/IP
331 * we could consider trying the rtime call first.
332 */
333 clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
334 if (clnt == NULL) {
335 msg("unable to create client handle to rpcbind.");
336 if (needfree)
337 free_eps(teps, tsrv.ep.ep_len);
338 return (0);
339 }
340
341 tv.tv_sec = 5;
342 tv.tv_usec = 0;
343 time_valid = 0;
344 status = clnt_call(clnt, RPCBPROC_GETTIME, xdr_void, NULL,
345 xdr_u_long, (char *)&thetime, tv);
346 /*
347 * The only error we check for is anything but success. In
348 * fact we could have seen PROGMISMATCH if talking to a 4.1
349 * machine (pmap v2) or TIMEDOUT if the net was busy.
350 */
351 if (status == RPC_SUCCESS)
352 time_valid = 1;
353 else {
354 int save;
355
356 /* Blow away possible stale CLNT handle. */
357 if (clnt != NULL) {
358 clnt_destroy(clnt);
359 clnt = NULL;
360 }
361
362 /*
363 * Convert PMAP address into timeservice address
364 * We take advantage of the fact that we "know" what
365 * the universal address looks like for inet transports.
366 *
367 * We also know that the internet timeservice is always
368 * listening on port 37.
369 */
370 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
371 sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
372
373 if (uaddr_to_sockaddr(ut, &sin)) {
374 msg("cannot convert timeservice uaddr to sockaddr.");
375 goto error;
376 }
377
378 s = _socket(AF_INET, type, 0);
379 if (s == -1) {
380 msg("unable to open fd to network.");
381 goto error;
382 }
383
384 /*
385 * Now depending on whether or not we're talking to
386 * UDP we set a timeout or not.
387 */
388 if (type == SOCK_DGRAM) {
389 struct timeval timeout = { 20, 0 };
390 struct sockaddr_in from;
391 fd_set readfds;
392 int res;
393
394 if (_sendto(s, &thetime, sizeof(thetime), 0,
395 (struct sockaddr *)&sin, sizeof(sin)) == -1) {
396 msg("udp : sendto failed.");
397 goto error;
398 }
399 do {
400 FD_ZERO(&readfds);
401 FD_SET(s, &readfds);
402 res = _select(_rpc_dtablesize(), &readfds,
403 (fd_set *)NULL, (fd_set *)NULL, &timeout);
404 } while (res < 0 && errno == EINTR);
405 if (res <= 0)
406 goto error;
407 len = sizeof(from);
408 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
409 (struct sockaddr *)&from, &len);
410 if (res == -1) {
411 msg("recvfrom failed on udp transport.");
412 goto error;
413 }
414 time_valid = 1;
415 } else {
416 int res;
417
418 oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
419 saw_alarm = 0; /* global tracking the alarm */
420 alarm(20); /* only wait 20 seconds */
421 res = _connect(s, (struct sockaddr *)&sin, sizeof(sin));
422 if (res == -1) {
423 msg("failed to connect to tcp endpoint.");
424 goto error;
425 }
426 if (saw_alarm) {
427 msg("alarm caught it, must be unreachable.");
428 goto error;
429 }
430 res = _read(s, (char *)&thetime, sizeof(thetime));
431 if (res != sizeof(thetime)) {
432 if (saw_alarm)
433 msg("timed out TCP call.");
434 else
435 msg("wrong size of results returned");
436
437 goto error;
438 }
439 time_valid = 1;
440 }
441 save = errno;
442 (void)_close(s);
443 errno = save;
444 s = RPC_ANYSOCK;
445
446 if (time_valid) {
447 thetime = ntohl(thetime);
448 thetime = thetime - TOFFSET; /* adjust to UNIX time */
449 } else
450 thetime = 0;
451 }
452
453 gettimeofday(&tv, 0);
454
455error:
456 /*
457 * clean up our allocated data structures.
458 */
459
460 if (s != RPC_ANYSOCK)
461 (void)_close(s);
462
463 if (clnt != NULL)
464 clnt_destroy(clnt);
465
466 alarm(0); /* reset that alarm if its outstanding */
467 if (oldsig) {
468 signal(SIGALRM, oldsig);
469 }
470
471 /*
472 * note, don't free uaddr strings until after we've made a
473 * copy of them.
474 */
475 if (time_valid) {
476 if (*uaddr == NULL)
477 *uaddr = strdup(useua);
478
479 /* Round to the nearest second */
480 tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
481 delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
482 tv.tv_sec - thetime;
483 td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
484 td->tv_usec = 0;
485 } else {
486 msg("unable to get the server's time.");
487 }
488
489 if (needfree)
490 free_eps(teps, tsrv.ep.ep_len);
491
492 return (time_valid);
493}