2 * Copyright (c) 1985, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
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33 * @(#)readmsg.c 8.1 (Berkeley) 6/6/93
34 * $FreeBSD: src/usr.sbin/timed/timed/readmsg.c,v 1.5.2.3 2001/08/31 08:02:05 kris Exp $
35 * $DragonFly: src/usr.sbin/timed/timed/readmsg.c,v 1.6 2004/09/05 02:20:15 dillon Exp $
40 extern char *tsptype[];
43 * LOOKAT checks if the message is of the requested type and comes from
44 * the right machine, returning 1 in case of affirmative answer
46 #define LOOKAT(msg, mtype, mfrom, netp, froms) \
47 (((mtype) == TSP_ANY || (mtype) == (msg).tsp_type) && \
48 ((mfrom) == 0 || !strcmp((mfrom), (msg).tsp_name)) && \
50 ((netp)->mask & (froms).sin_addr.s_addr) == (netp)->net.s_addr))
52 struct timeval rtime, rwait, rtout;
54 static struct tsplist {
57 struct sockaddr_in addr;
60 struct sockaddr_in from;
61 struct netinfo *fromnet;
62 struct timeval from_when;
65 * `readmsg' returns message `type' sent by `machfrom' if it finds it
66 * either in the receive queue, or in a linked list of previously received
67 * messages that it maintains.
68 * Otherwise it waits to see if the appropriate message arrives within
69 * `intvl' seconds. If not, it returns NULL.
73 readmsg(int type, char *machfrom, struct timeval *intvl,
74 struct netinfo *netfrom)
78 static struct tsplist *head = &msgslist;
79 static struct tsplist *tail = &msgslist;
80 static int msgcnt = 0;
87 fprintf(fd, "readmsg: looking for %s from %s, %s\n",
88 tsptype[type], machfrom == NULL ? "ANY" : machfrom,
89 netfrom == NULL ? "ANYNET" : inet_ntoa(netfrom->net));
92 for (ptr = head->p; ptr != 0; ptr = ptr->p) {
93 /* do not repeat the hundreds of messages */
96 fprintf(fd,"\t ...%d skipped\n",
102 fprintf(fd, length > 1 ? "\t" : "queue:\t");
103 print(&ptr->info, &ptr->addr);
112 * Look for the requested message scanning through the
113 * linked list. If found, return it and free the space
116 while (ptr != NULL) {
117 if (LOOKAT(ptr->info, type, machfrom, netfrom, ptr->addr)) {
121 from_when = ptr->when;
128 for (ntp = nettab; ntp != NULL; ntp = ntp->next) {
129 if ((ntp->mask & from.sin_addr.s_addr) ==
138 fprintf(fd, "readmsg: found ");
139 print(&msgin, &from);
142 /* The protocol can get far behind. When it does, it gets
143 * hopelessly confused. So delete duplicate messages.
145 for (ptr = prev; (ptr = ptr->p) != NULL; prev = ptr) {
146 if (ptr->addr.sin_addr.s_addr
147 == from.sin_addr.s_addr
148 && ptr->info.tsp_type == msgin.tsp_type) {
150 fprintf(fd, "\tdup ");
163 * If the message was not in the linked list, it may still be
164 * coming from the network. Set the timer and wait
165 * on a select to read the next incoming message: if it is the
166 * right one, return it, otherwise insert it in the linked list.
169 gettimeofday(&rtout, 0);
170 timevaladd(&rtout, intvl);
173 gettimeofday(&rtime, 0);
174 timevalsub(&rwait, &rtout, &rtime);
175 if (rwait.tv_sec < 0)
176 rwait.tv_sec = rwait.tv_usec = 0;
177 else if (rwait.tv_sec == 0
178 && rwait.tv_usec < 1000000/CLK_TCK)
179 rwait.tv_usec = 1000000/CLK_TCK;
182 fprintf(fd, "readmsg: wait %ld.%6ld at %s\n",
183 rwait.tv_sec, rwait.tv_usec, date());
184 /* Notice a full disk, as we flush trace info.
185 * It is better to flush periodically than at
186 * every line because the tracing consists of bursts
187 * of many lines. Without care, tracing slows
188 * down the code enough to break the protocol.
190 if (rwait.tv_sec != 0
191 && EOF == fflush(fd))
192 traceoff("Tracing ended for cause at %s\n");
195 FD_SET(sock, &ready);
196 if (!select(sock+1, &ready, (fd_set *)0, (fd_set *)0,
198 if (rwait.tv_sec == 0 && rwait.tv_usec == 0)
202 length = sizeof(from);
203 if ((n = recvfrom(sock, (char *)&msgin, sizeof(struct tsp), 0,
204 (struct sockaddr*)&from, &length)) < 0) {
205 syslog(LOG_ERR, "recvfrom: %m");
209 * The 4.3BSD protocol spec had a 32-byte tsp_name field, and
210 * this is still OS-dependent. Demand that the packet is at
211 * least long enough to hold a 4.3BSD packet.
213 if (n < (ssize_t)(sizeof(struct tsp) - MAXHOSTNAMELEN + 32)) {
215 "short packet (%u/%u bytes) from %s",
216 n, sizeof(struct tsp) - MAXHOSTNAMELEN + 32,
217 inet_ntoa(from.sin_addr));
220 gettimeofday(&from_when, (struct timezone *)0);
221 bytehostorder(&msgin);
223 if (msgin.tsp_vers > TSPVERSION) {
225 fprintf(fd,"readmsg: version mismatch\n");
226 /* should do a dump of the packet */
231 if (memchr(msgin.tsp_name,
232 '\0', sizeof msgin.tsp_name) == NULL) {
233 syslog(LOG_NOTICE, "hostname field not NUL terminated "
234 "in packet from %s", inet_ntoa(from.sin_addr));
239 for (ntp = nettab; ntp != NULL; ntp = ntp->next)
240 if ((ntp->mask & from.sin_addr.s_addr) ==
247 * drop packets from nets we are ignoring permanently
249 if (fromnet == NULL) {
251 * The following messages may originate on
252 * this host with an ignored network address
254 if (msgin.tsp_type != TSP_TRACEON &&
255 msgin.tsp_type != TSP_SETDATE &&
256 msgin.tsp_type != TSP_MSITE &&
257 msgin.tsp_type != TSP_TEST &&
258 msgin.tsp_type != TSP_TRACEOFF) {
260 fprintf(fd,"readmsg: discard null net ");
261 print(&msgin, &from);
268 * Throw away messages coming from this machine,
269 * unless they are of some particular type.
270 * This gets rid of broadcast messages and reduces
271 * master processing time.
273 if (!strcmp(msgin.tsp_name, hostname)
274 && msgin.tsp_type != TSP_SETDATE
275 && msgin.tsp_type != TSP_TEST
276 && msgin.tsp_type != TSP_MSITE
277 && msgin.tsp_type != TSP_TRACEON
278 && msgin.tsp_type != TSP_TRACEOFF
279 && msgin.tsp_type != TSP_LOOP) {
281 fprintf(fd, "readmsg: discard own ");
282 print(&msgin, &from);
288 * Send acknowledgements here; this is faster and
289 * avoids deadlocks that would occur if acks were
290 * sent from a higher level routine. Different
291 * acknowledgements are necessary, depending on
294 if (fromnet == NULL) /* do not de-reference 0 */
296 else if (fromnet->status == MASTER)
298 else if (fromnet->status == SLAVE)
303 if (LOOKAT(msgin, type, machfrom, netfrom, from)) {
305 fprintf(fd, "readmsg: ");
306 print(&msgin, &from);
309 } else if (++msgcnt > NHOSTS*3) {
311 /* The protocol gets hopelessly confused if it gets too far
312 * behind. However, it seems able to recover from all cases of lost
313 * packets. Therefore, if we are swamped, throw everything away.
317 "readmsg: discarding %d msgs\n",
320 while ((ptr=head->p) != NULL) {
326 tail->p = (struct tsplist *)
327 malloc(sizeof(struct tsplist));
332 /* timestamp msgs so SETTIMEs are correct */
333 tail->when = from_when;
339 * Send the necessary acknowledgements:
340 * only the type ACK is to be sent by a slave
346 switch(msgin.tsp_type) {
356 fprintf(fd, "Slaveack: ");
357 print(&msgin, &from);
359 xmit(TSP_ACK,msgin.tsp_seq, &from);
364 fprintf(fd, "Slaveack: no ack: ");
365 print(&msgin, &from);
372 * Certain packets may arrive from this machine on ignored networks.
373 * These packets should be acknowledged.
379 switch(msgin.tsp_type) {
385 fprintf(fd, "Ignoreack: ");
386 print(&msgin, &from);
388 xmit(TSP_ACK,msgin.tsp_seq, &from);
393 fprintf(fd, "Ignoreack: no ack: ");
394 print(&msgin, &from);
401 * `masterack' sends the necessary acknowledgments
402 * to the messages received by a master
410 resp.tsp_vers = TSPVERSION;
411 strlcpy(resp.tsp_name, hostname, sizeof(resp.tsp_name));
413 switch(msgin.tsp_type) {
420 fprintf(fd, "Masterack: ");
421 print(&msgin, &from);
423 xmit(TSP_ACK,msgin.tsp_seq, &from);
429 fprintf(fd, "Masterack: ");
430 print(&msgin, &from);
432 xmit(TSP_MASTERACK,msgin.tsp_seq, &from);
437 fprintf(fd,"Masterack: no ack: ");
438 print(&msgin, &from);
445 * Print a TSP message
448 print(struct tsp *msg, struct sockaddr_in *addr)
453 if (msg->tsp_type >= TSPTYPENUMBER) {
454 fprintf(fd, "bad type (%u) on packet from %s\n",
455 msg->tsp_type, inet_ntoa(addr->sin_addr));
459 switch (msg->tsp_type) {
462 fprintf(fd, "%s %d %-6u #%d %-15s %s\n",
463 tsptype[msg->tsp_type],
467 inet_ntoa(addr->sin_addr),
474 tsp_time_sec = msg->tsp_time.tv_sec;
475 strlcpy(tm, ctime(&tsp_time_sec)+3+1, sizeof(tm));
476 fprintf(fd, "%s %d %-6u %s %-15s %s\n",
477 tsptype[msg->tsp_type],
481 inet_ntoa(addr->sin_addr),
486 fprintf(fd, "%s %d %-6u (%ld,%ld) %-15s %s\n",
487 tsptype[msg->tsp_type],
490 msg->tsp_time.tv_sec,
491 msg->tsp_time.tv_usec,
492 inet_ntoa(addr->sin_addr),
497 fprintf(fd, "%s %d %-6u %-15s %s\n",
498 tsptype[msg->tsp_type],
501 inet_ntoa(addr->sin_addr),