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
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/lib/libc/rpc/auth_time.c 92990 2002-03-22 23:18:37Z obrien $");
32
33#include "namespace.h"
34#include <stdio.h>
35#include <syslog.h>
36#include <string.h>
37#include <stdlib.h>
38#include <unistd.h>
39#include <netdb.h>
40#include <sys/signal.h>
41#include <sys/errno.h>
42#include <sys/socket.h>
43#include <netinet/in.h>
44#include <arpa/inet.h>
45#include <rpc/rpc.h>
46#include <rpc/rpc_com.h>
47#include <rpc/rpcb_prot.h>
48#undef NIS
49#include <rpcsvc/nis.h>
50#include "un-namespace.h"
51
52#ifdef TESTING
53#define msg(x) printf("ERROR: %s\n", x)
54/* #define msg(x) syslog(LOG_ERR, "%s", x) */
55#else
56#define msg(x)
57#endif
58
59static int saw_alarm = 0;
60
61static void
62alarm_hndler(s)
63 int s;
64{
65 saw_alarm = 1;
66 return;
67}
68
69/*
70 * The internet time server defines the epoch to be Jan 1, 1900
71 * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
72 * from internet time-service time, into UNIX time we subtract the
73 * following offset :
74 */
75#define NYEARS (1970 - 1900)
76#define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
77
78
79/*
80 * Stolen from rpc.nisd:
81 * Turn a 'universal address' into a struct sockaddr_in.
82 * Bletch.
83 */
84static int uaddr_to_sockaddr(uaddr, sin)
85#ifdef foo
86 endpoint *endpt;
87#endif
88 char *uaddr;
89 struct sockaddr_in *sin;
90{
91 unsigned char p_bytes[2];
92 int i;
93 unsigned long a[6];
94
95 i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
96 &a[3], &a[4], &a[5]);
97
98 if (i < 6)
99 return(1);
100
101 for (i = 0; i < 4; i++)
102 sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
103
104 p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
105 p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
106
107 sin->sin_family = AF_INET; /* always */
108 bcopy((char *)&p_bytes, (char *)&sin->sin_port, 2);
109
110 return (0);
111}
112
113/*
114 * free_eps()
115 *
116 * Free the strings that were strduped into the eps structure.
117 */
118static void
119free_eps(eps, num)
120 endpoint eps[];
121 int num;
122{
123 int i;
124
125 for (i = 0; i < num; i++) {
126 free(eps[i].uaddr);
127 free(eps[i].proto);
128 free(eps[i].family);
129 }
130 return;
131}
132
133/*
134 * get_server()
135 *
136 * This function constructs a nis_server structure description for the
137 * indicated hostname.
138 *
139 * NOTE: There is a chance we may end up recursing here due to the
140 * fact that gethostbyname() could do an NIS search. Ideally, the
141 * NIS+ server will call __rpc_get_time_offset() with the nis_server
142 * structure already populated.
143 */
144static nis_server *
145get_server(sin, host, srv, eps, maxep)
146 struct sockaddr_in *sin;
147 char *host; /* name of the time host */
148 nis_server *srv; /* nis_server struct to use. */
149 endpoint eps[]; /* array of endpoints */
150 int maxep; /* max array size */
151{
152 char hname[256];
153 int num_ep = 0, i;
154 struct hostent *he;
155 struct hostent dummy;
156 char *ptr[2];
157
158 if (host == NULL && sin == NULL)
159 return (NULL);
160
161 if (sin == NULL) {
162 he = gethostbyname(host);
163 if (he == NULL)
164 return(NULL);
165 } else {
166 he = &dummy;
167 ptr[0] = (char *)&sin->sin_addr.s_addr;
168 ptr[1] = NULL;
169 dummy.h_addr_list = ptr;
170 }
171
172 /*
173 * This is lame. We go around once for TCP, then again
174 * for UDP.
175 */
176 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
177 i++, num_ep++) {
178 struct in_addr *a;
179
180 a = (struct in_addr *)he->h_addr_list[i];
181 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
182 eps[num_ep].uaddr = strdup(hname);
183 eps[num_ep].family = strdup("inet");
184 eps[num_ep].proto = strdup("tcp");
185 }
186
187 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
188 i++, num_ep++) {
189 struct in_addr *a;
190
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("udp");
196 }
197
198 srv->name = (nis_name) host;
199 srv->ep.ep_len = num_ep;
200 srv->ep.ep_val = eps;
201 srv->key_type = NIS_PK_NONE;
202 srv->pkey.n_bytes = NULL;
203 srv->pkey.n_len = 0;
204 return (srv);
205}
206
207/*
208 * __rpc_get_time_offset()
209 *
210 * This function uses a nis_server structure to contact the a remote
211 * machine (as named in that structure) and returns the offset in time
212 * between that machine and this one. This offset is returned in seconds
213 * and may be positive or negative.
214 *
215 * The first time through, a lot of fiddling is done with the netconfig
216 * stuff to find a suitable transport. The function is very aggressive
217 * about choosing UDP or at worst TCP if it can. This is because
218 * those transports support both the RCPBIND call and the internet
219 * time service.
220 *
221 * Once through, *uaddr is set to the universal address of
222 * the machine and *netid is set to the local netid for the transport
223 * that uaddr goes with. On the second call, the netconfig stuff
224 * is skipped and the uaddr/netid pair are used to fetch the netconfig
225 * structure and to then contact the machine for the time.
226 *
227 * td = "server" - "client"
228 */
229int
230__rpc_get_time_offset(td, srv, thost, uaddr, netid)
231 struct timeval *td; /* Time difference */
232 nis_server *srv; /* NIS Server description */
233 char *thost; /* if no server, this is the timehost */
234 char **uaddr; /* known universal address */
235 struct sockaddr_in *netid; /* known network identifier */
236{
237 CLIENT *clnt; /* Client handle */
238 endpoint *ep, /* useful endpoints */
239 *useep = NULL; /* endpoint of xp */
240 char *useua = NULL; /* uaddr of selected xp */
241 int epl, i; /* counters */
242 enum clnt_stat status; /* result of clnt_call */
243 u_long thetime, delta;
244 int needfree = 0;
245 struct timeval tv;
246 int time_valid;
247 int udp_ep = -1, tcp_ep = -1;
248 int a1, a2, a3, a4;
249 char ut[64], ipuaddr[64];
250 endpoint teps[32];
251 nis_server tsrv;
252 void (*oldsig)() = NULL; /* old alarm handler */
253 struct sockaddr_in sin;
254 int s = RPC_ANYSOCK, len;
255 int type = 0;
256
257 td->tv_sec = 0;
258 td->tv_usec = 0;
259
260 /*
261 * First check to see if we need to find and address for this
262 * server.
263 */
264 if (*uaddr == NULL) {
265 if ((srv != NULL) && (thost != NULL)) {
266 msg("both timehost and srv pointer used!");
267 return (0);
268 }
269 if (! srv) {
270 srv = get_server(netid, thost, &tsrv, teps, 32);
271 if (srv == NULL) {
272 msg("unable to contruct server data.");
273 return (0);
274 }
275 needfree = 1; /* need to free data in endpoints */
276 }
277
278 ep = srv->ep.ep_val;
279 epl = srv->ep.ep_len;
280
281 /* Identify the TCP and UDP endpoints */
282 for (i = 0;
283 (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
284 if (strcasecmp(ep[i].proto, "udp") == 0)
285 udp_ep = i;
286 if (strcasecmp(ep[i].proto, "tcp") == 0)
287 tcp_ep = i;
288 }
289
290 /* Check to see if it is UDP or TCP */
291 if (tcp_ep > -1) {
292 useep = &ep[tcp_ep];
293 useua = ep[tcp_ep].uaddr;
294 type = SOCK_STREAM;
295 } else if (udp_ep > -1) {
296 useep = &ep[udp_ep];
297 useua = ep[udp_ep].uaddr;
298 type = SOCK_DGRAM;
299 }
300
301 if (useep == NULL) {
302 msg("no acceptable transport endpoints.");
303 if (needfree)
304 free_eps(teps, tsrv.ep.ep_len);
305 return (0);
306 }
307 }
308
309 /*
310 * Create a sockaddr from the uaddr.
311 */
312 if (*uaddr != NULL)
313 useua = *uaddr;
314
315 /* Fixup test for NIS+ */
316 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
317 sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
318 useua = &ipuaddr[0];
319
320 bzero((char *)&sin, sizeof(sin));
321 if (uaddr_to_sockaddr(useua, &sin)) {
322 msg("unable to translate uaddr to sockaddr.");
323 if (needfree)
324 free_eps(teps, tsrv.ep.ep_len);
325 return (0);
326 }
327
328 /*
329 * Create the client handle to rpcbind. Note we always try
330 * version 3 since that is the earliest version that supports
331 * the RPCB_GETTIME call. Also it is the version that comes
332 * standard with SVR4. Since most everyone supports TCP/IP
333 * we could consider trying the rtime call first.
334 */
335 clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
336 if (clnt == NULL) {
337 msg("unable to create client handle to rpcbind.");
338 if (needfree)
339 free_eps(teps, tsrv.ep.ep_len);
340 return (0);
341 }
342
343 tv.tv_sec = 5;
344 tv.tv_usec = 0;
345 time_valid = 0;
346 status = clnt_call(clnt, RPCBPROC_GETTIME, xdr_void, NULL,
347 xdr_u_long, (char *)&thetime, tv);
348 /*
349 * The only error we check for is anything but success. In
350 * fact we could have seen PROGMISMATCH if talking to a 4.1
351 * machine (pmap v2) or TIMEDOUT if the net was busy.
352 */
353 if (status == RPC_SUCCESS)
354 time_valid = 1;
355 else {
356 int save;
357
358 /* Blow away possible stale CLNT handle. */
359 if (clnt != NULL) {
360 clnt_destroy(clnt);
361 clnt = NULL;
362 }
363
364 /*
365 * Convert PMAP address into timeservice address
366 * We take advantage of the fact that we "know" what
367 * the universal address looks like for inet transports.
368 *
369 * We also know that the internet timeservice is always
370 * listening on port 37.
371 */
372 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
373 sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
374
375 if (uaddr_to_sockaddr(ut, &sin)) {
376 msg("cannot convert timeservice uaddr to sockaddr.");
377 goto error;
378 }
379
380 s = _socket(AF_INET, type, 0);
381 if (s == -1) {
382 msg("unable to open fd to network.");
383 goto error;
384 }
385
386 /*
387 * Now depending on whether or not we're talking to
388 * UDP we set a timeout or not.
389 */
390 if (type == SOCK_DGRAM) {
391 struct timeval timeout = { 20, 0 };
392 struct sockaddr_in from;
393 fd_set readfds;
394 int res;
395
396 if (_sendto(s, &thetime, sizeof(thetime), 0,
397 (struct sockaddr *)&sin, sizeof(sin)) == -1) {
398 msg("udp : sendto failed.");
399 goto error;
400 }
401 do {
402 FD_ZERO(&readfds);
403 FD_SET(s, &readfds);
404 res = _select(_rpc_dtablesize(), &readfds,
405 (fd_set *)NULL, (fd_set *)NULL, &timeout);
406 } while (res < 0 && errno == EINTR);
407 if (res <= 0)
408 goto error;
409 len = sizeof(from);
410 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
411 (struct sockaddr *)&from, &len);
412 if (res == -1) {
413 msg("recvfrom failed on udp transport.");
414 goto error;
415 }
416 time_valid = 1;
417 } else {
418 int res;
419
420 oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
421 saw_alarm = 0; /* global tracking the alarm */
422 alarm(20); /* only wait 20 seconds */
423 res = _connect(s, (struct sockaddr *)&sin, sizeof(sin));
424 if (res == -1) {
425 msg("failed to connect to tcp endpoint.");
426 goto error;
427 }
428 if (saw_alarm) {
429 msg("alarm caught it, must be unreachable.");
430 goto error;
431 }
432 res = _read(s, (char *)&thetime, sizeof(thetime));
433 if (res != sizeof(thetime)) {
434 if (saw_alarm)
435 msg("timed out TCP call.");
436 else
437 msg("wrong size of results returned");
438
439 goto error;
440 }
441 time_valid = 1;
442 }
443 save = errno;
444 (void)_close(s);
445 errno = save;
446 s = RPC_ANYSOCK;
447
448 if (time_valid) {
449 thetime = ntohl(thetime);
450 thetime = thetime - TOFFSET; /* adjust to UNIX time */
451 } else
452 thetime = 0;
453 }
454
455 gettimeofday(&tv, 0);
456
457error:
458 /*
459 * clean up our allocated data structures.
460 */
461
462 if (s != RPC_ANYSOCK)
463 (void)_close(s);
464
465 if (clnt != NULL)
466 clnt_destroy(clnt);
467
468 alarm(0); /* reset that alarm if its outstanding */
469 if (oldsig) {
470 signal(SIGALRM, oldsig);
471 }
472
473 /*
474 * note, don't free uaddr strings until after we've made a
475 * copy of them.
476 */
477 if (time_valid) {
478 if (*uaddr == NULL)
479 *uaddr = strdup(useua);
480
481 /* Round to the nearest second */
482 tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
483 delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
484 tv.tv_sec - thetime;
485 td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
486 td->tv_usec = 0;
487 } else {
488 msg("unable to get the server's time.");
489 }
490
491 if (needfree)
492 free_eps(teps, tsrv.ep.ep_len);
493
494 return (time_valid);
495}
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
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/lib/libc/rpc/auth_time.c 92990 2002-03-22 23:18:37Z obrien $");
32
33#include "namespace.h"
34#include <stdio.h>
35#include <syslog.h>
36#include <string.h>
37#include <stdlib.h>
38#include <unistd.h>
39#include <netdb.h>
40#include <sys/signal.h>
41#include <sys/errno.h>
42#include <sys/socket.h>
43#include <netinet/in.h>
44#include <arpa/inet.h>
45#include <rpc/rpc.h>
46#include <rpc/rpc_com.h>
47#include <rpc/rpcb_prot.h>
48#undef NIS
49#include <rpcsvc/nis.h>
50#include "un-namespace.h"
51
52#ifdef TESTING
53#define msg(x) printf("ERROR: %s\n", x)
54/* #define msg(x) syslog(LOG_ERR, "%s", x) */
55#else
56#define msg(x)
57#endif
58
59static int saw_alarm = 0;
60
61static void
62alarm_hndler(s)
63 int s;
64{
65 saw_alarm = 1;
66 return;
67}
68
69/*
70 * The internet time server defines the epoch to be Jan 1, 1900
71 * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
72 * from internet time-service time, into UNIX time we subtract the
73 * following offset :
74 */
75#define NYEARS (1970 - 1900)
76#define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
77
78
79/*
80 * Stolen from rpc.nisd:
81 * Turn a 'universal address' into a struct sockaddr_in.
82 * Bletch.
83 */
84static int uaddr_to_sockaddr(uaddr, sin)
85#ifdef foo
86 endpoint *endpt;
87#endif
88 char *uaddr;
89 struct sockaddr_in *sin;
90{
91 unsigned char p_bytes[2];
92 int i;
93 unsigned long a[6];
94
95 i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
96 &a[3], &a[4], &a[5]);
97
98 if (i < 6)
99 return(1);
100
101 for (i = 0; i < 4; i++)
102 sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
103
104 p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
105 p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
106
107 sin->sin_family = AF_INET; /* always */
108 bcopy((char *)&p_bytes, (char *)&sin->sin_port, 2);
109
110 return (0);
111}
112
113/*
114 * free_eps()
115 *
116 * Free the strings that were strduped into the eps structure.
117 */
118static void
119free_eps(eps, num)
120 endpoint eps[];
121 int num;
122{
123 int i;
124
125 for (i = 0; i < num; i++) {
126 free(eps[i].uaddr);
127 free(eps[i].proto);
128 free(eps[i].family);
129 }
130 return;
131}
132
133/*
134 * get_server()
135 *
136 * This function constructs a nis_server structure description for the
137 * indicated hostname.
138 *
139 * NOTE: There is a chance we may end up recursing here due to the
140 * fact that gethostbyname() could do an NIS search. Ideally, the
141 * NIS+ server will call __rpc_get_time_offset() with the nis_server
142 * structure already populated.
143 */
144static nis_server *
145get_server(sin, host, srv, eps, maxep)
146 struct sockaddr_in *sin;
147 char *host; /* name of the time host */
148 nis_server *srv; /* nis_server struct to use. */
149 endpoint eps[]; /* array of endpoints */
150 int maxep; /* max array size */
151{
152 char hname[256];
153 int num_ep = 0, i;
154 struct hostent *he;
155 struct hostent dummy;
156 char *ptr[2];
157
158 if (host == NULL && sin == NULL)
159 return (NULL);
160
161 if (sin == NULL) {
162 he = gethostbyname(host);
163 if (he == NULL)
164 return(NULL);
165 } else {
166 he = &dummy;
167 ptr[0] = (char *)&sin->sin_addr.s_addr;
168 ptr[1] = NULL;
169 dummy.h_addr_list = ptr;
170 }
171
172 /*
173 * This is lame. We go around once for TCP, then again
174 * for UDP.
175 */
176 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
177 i++, num_ep++) {
178 struct in_addr *a;
179
180 a = (struct in_addr *)he->h_addr_list[i];
181 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
182 eps[num_ep].uaddr = strdup(hname);
183 eps[num_ep].family = strdup("inet");
184 eps[num_ep].proto = strdup("tcp");
185 }
186
187 for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
188 i++, num_ep++) {
189 struct in_addr *a;
190
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("udp");
196 }
197
198 srv->name = (nis_name) host;
199 srv->ep.ep_len = num_ep;
200 srv->ep.ep_val = eps;
201 srv->key_type = NIS_PK_NONE;
202 srv->pkey.n_bytes = NULL;
203 srv->pkey.n_len = 0;
204 return (srv);
205}
206
207/*
208 * __rpc_get_time_offset()
209 *
210 * This function uses a nis_server structure to contact the a remote
211 * machine (as named in that structure) and returns the offset in time
212 * between that machine and this one. This offset is returned in seconds
213 * and may be positive or negative.
214 *
215 * The first time through, a lot of fiddling is done with the netconfig
216 * stuff to find a suitable transport. The function is very aggressive
217 * about choosing UDP or at worst TCP if it can. This is because
218 * those transports support both the RCPBIND call and the internet
219 * time service.
220 *
221 * Once through, *uaddr is set to the universal address of
222 * the machine and *netid is set to the local netid for the transport
223 * that uaddr goes with. On the second call, the netconfig stuff
224 * is skipped and the uaddr/netid pair are used to fetch the netconfig
225 * structure and to then contact the machine for the time.
226 *
227 * td = "server" - "client"
228 */
229int
230__rpc_get_time_offset(td, srv, thost, uaddr, netid)
231 struct timeval *td; /* Time difference */
232 nis_server *srv; /* NIS Server description */
233 char *thost; /* if no server, this is the timehost */
234 char **uaddr; /* known universal address */
235 struct sockaddr_in *netid; /* known network identifier */
236{
237 CLIENT *clnt; /* Client handle */
238 endpoint *ep, /* useful endpoints */
239 *useep = NULL; /* endpoint of xp */
240 char *useua = NULL; /* uaddr of selected xp */
241 int epl, i; /* counters */
242 enum clnt_stat status; /* result of clnt_call */
243 u_long thetime, delta;
244 int needfree = 0;
245 struct timeval tv;
246 int time_valid;
247 int udp_ep = -1, tcp_ep = -1;
248 int a1, a2, a3, a4;
249 char ut[64], ipuaddr[64];
250 endpoint teps[32];
251 nis_server tsrv;
252 void (*oldsig)() = NULL; /* old alarm handler */
253 struct sockaddr_in sin;
254 int s = RPC_ANYSOCK, len;
255 int type = 0;
256
257 td->tv_sec = 0;
258 td->tv_usec = 0;
259
260 /*
261 * First check to see if we need to find and address for this
262 * server.
263 */
264 if (*uaddr == NULL) {
265 if ((srv != NULL) && (thost != NULL)) {
266 msg("both timehost and srv pointer used!");
267 return (0);
268 }
269 if (! srv) {
270 srv = get_server(netid, thost, &tsrv, teps, 32);
271 if (srv == NULL) {
272 msg("unable to contruct server data.");
273 return (0);
274 }
275 needfree = 1; /* need to free data in endpoints */
276 }
277
278 ep = srv->ep.ep_val;
279 epl = srv->ep.ep_len;
280
281 /* Identify the TCP and UDP endpoints */
282 for (i = 0;
283 (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
284 if (strcasecmp(ep[i].proto, "udp") == 0)
285 udp_ep = i;
286 if (strcasecmp(ep[i].proto, "tcp") == 0)
287 tcp_ep = i;
288 }
289
290 /* Check to see if it is UDP or TCP */
291 if (tcp_ep > -1) {
292 useep = &ep[tcp_ep];
293 useua = ep[tcp_ep].uaddr;
294 type = SOCK_STREAM;
295 } else if (udp_ep > -1) {
296 useep = &ep[udp_ep];
297 useua = ep[udp_ep].uaddr;
298 type = SOCK_DGRAM;
299 }
300
301 if (useep == NULL) {
302 msg("no acceptable transport endpoints.");
303 if (needfree)
304 free_eps(teps, tsrv.ep.ep_len);
305 return (0);
306 }
307 }
308
309 /*
310 * Create a sockaddr from the uaddr.
311 */
312 if (*uaddr != NULL)
313 useua = *uaddr;
314
315 /* Fixup test for NIS+ */
316 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
317 sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
318 useua = &ipuaddr[0];
319
320 bzero((char *)&sin, sizeof(sin));
321 if (uaddr_to_sockaddr(useua, &sin)) {
322 msg("unable to translate uaddr to sockaddr.");
323 if (needfree)
324 free_eps(teps, tsrv.ep.ep_len);
325 return (0);
326 }
327
328 /*
329 * Create the client handle to rpcbind. Note we always try
330 * version 3 since that is the earliest version that supports
331 * the RPCB_GETTIME call. Also it is the version that comes
332 * standard with SVR4. Since most everyone supports TCP/IP
333 * we could consider trying the rtime call first.
334 */
335 clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
336 if (clnt == NULL) {
337 msg("unable to create client handle to rpcbind.");
338 if (needfree)
339 free_eps(teps, tsrv.ep.ep_len);
340 return (0);
341 }
342
343 tv.tv_sec = 5;
344 tv.tv_usec = 0;
345 time_valid = 0;
346 status = clnt_call(clnt, RPCBPROC_GETTIME, xdr_void, NULL,
347 xdr_u_long, (char *)&thetime, tv);
348 /*
349 * The only error we check for is anything but success. In
350 * fact we could have seen PROGMISMATCH if talking to a 4.1
351 * machine (pmap v2) or TIMEDOUT if the net was busy.
352 */
353 if (status == RPC_SUCCESS)
354 time_valid = 1;
355 else {
356 int save;
357
358 /* Blow away possible stale CLNT handle. */
359 if (clnt != NULL) {
360 clnt_destroy(clnt);
361 clnt = NULL;
362 }
363
364 /*
365 * Convert PMAP address into timeservice address
366 * We take advantage of the fact that we "know" what
367 * the universal address looks like for inet transports.
368 *
369 * We also know that the internet timeservice is always
370 * listening on port 37.
371 */
372 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
373 sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
374
375 if (uaddr_to_sockaddr(ut, &sin)) {
376 msg("cannot convert timeservice uaddr to sockaddr.");
377 goto error;
378 }
379
380 s = _socket(AF_INET, type, 0);
381 if (s == -1) {
382 msg("unable to open fd to network.");
383 goto error;
384 }
385
386 /*
387 * Now depending on whether or not we're talking to
388 * UDP we set a timeout or not.
389 */
390 if (type == SOCK_DGRAM) {
391 struct timeval timeout = { 20, 0 };
392 struct sockaddr_in from;
393 fd_set readfds;
394 int res;
395
396 if (_sendto(s, &thetime, sizeof(thetime), 0,
397 (struct sockaddr *)&sin, sizeof(sin)) == -1) {
398 msg("udp : sendto failed.");
399 goto error;
400 }
401 do {
402 FD_ZERO(&readfds);
403 FD_SET(s, &readfds);
404 res = _select(_rpc_dtablesize(), &readfds,
405 (fd_set *)NULL, (fd_set *)NULL, &timeout);
406 } while (res < 0 && errno == EINTR);
407 if (res <= 0)
408 goto error;
409 len = sizeof(from);
410 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
411 (struct sockaddr *)&from, &len);
412 if (res == -1) {
413 msg("recvfrom failed on udp transport.");
414 goto error;
415 }
416 time_valid = 1;
417 } else {
418 int res;
419
420 oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
421 saw_alarm = 0; /* global tracking the alarm */
422 alarm(20); /* only wait 20 seconds */
423 res = _connect(s, (struct sockaddr *)&sin, sizeof(sin));
424 if (res == -1) {
425 msg("failed to connect to tcp endpoint.");
426 goto error;
427 }
428 if (saw_alarm) {
429 msg("alarm caught it, must be unreachable.");
430 goto error;
431 }
432 res = _read(s, (char *)&thetime, sizeof(thetime));
433 if (res != sizeof(thetime)) {
434 if (saw_alarm)
435 msg("timed out TCP call.");
436 else
437 msg("wrong size of results returned");
438
439 goto error;
440 }
441 time_valid = 1;
442 }
443 save = errno;
444 (void)_close(s);
445 errno = save;
446 s = RPC_ANYSOCK;
447
448 if (time_valid) {
449 thetime = ntohl(thetime);
450 thetime = thetime - TOFFSET; /* adjust to UNIX time */
451 } else
452 thetime = 0;
453 }
454
455 gettimeofday(&tv, 0);
456
457error:
458 /*
459 * clean up our allocated data structures.
460 */
461
462 if (s != RPC_ANYSOCK)
463 (void)_close(s);
464
465 if (clnt != NULL)
466 clnt_destroy(clnt);
467
468 alarm(0); /* reset that alarm if its outstanding */
469 if (oldsig) {
470 signal(SIGALRM, oldsig);
471 }
472
473 /*
474 * note, don't free uaddr strings until after we've made a
475 * copy of them.
476 */
477 if (time_valid) {
478 if (*uaddr == NULL)
479 *uaddr = strdup(useua);
480
481 /* Round to the nearest second */
482 tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
483 delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
484 tv.tv_sec - thetime;
485 td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
486 td->tv_usec = 0;
487 } else {
488 msg("unable to get the server's time.");
489 }
490
491 if (needfree)
492 free_eps(teps, tsrv.ep.ep_len);
493
494 return (time_valid);
495}