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, NULL, NULL, &rwait)) {
197 if (rwait.tv_sec == 0 && rwait.tv_usec == 0)
201 length = sizeof(from);
202 if ((n = recvfrom(sock, (char *)&msgin, sizeof(struct tsp), 0,
203 (struct sockaddr*)&from, &length)) < 0) {
204 syslog(LOG_ERR, "recvfrom: %m");
208 * The 4.3BSD protocol spec had a 32-byte tsp_name field, and
209 * this is still OS-dependent. Demand that the packet is at
210 * least long enough to hold a 4.3BSD packet.
212 if (n < (ssize_t)(sizeof(struct tsp) - MAXHOSTNAMELEN + 32)) {
214 "short packet (%u/%u bytes) from %s",
215 n, sizeof(struct tsp) - MAXHOSTNAMELEN + 32,
216 inet_ntoa(from.sin_addr));
219 gettimeofday(&from_when, NULL);
220 bytehostorder(&msgin);
222 if (msgin.tsp_vers > TSPVERSION) {
224 fprintf(fd,"readmsg: version mismatch\n");
225 /* should do a dump of the packet */
230 if (memchr(msgin.tsp_name,
231 '\0', sizeof msgin.tsp_name) == NULL) {
232 syslog(LOG_NOTICE, "hostname field not NUL terminated "
233 "in packet from %s", inet_ntoa(from.sin_addr));
238 for (ntp = nettab; ntp != NULL; ntp = ntp->next)
239 if ((ntp->mask & from.sin_addr.s_addr) ==
246 * drop packets from nets we are ignoring permanently
248 if (fromnet == NULL) {
250 * The following messages may originate on
251 * this host with an ignored network address
253 if (msgin.tsp_type != TSP_TRACEON &&
254 msgin.tsp_type != TSP_SETDATE &&
255 msgin.tsp_type != TSP_MSITE &&
256 msgin.tsp_type != TSP_TEST &&
257 msgin.tsp_type != TSP_TRACEOFF) {
259 fprintf(fd,"readmsg: discard null net ");
260 print(&msgin, &from);
267 * Throw away messages coming from this machine,
268 * unless they are of some particular type.
269 * This gets rid of broadcast messages and reduces
270 * master processing time.
272 if (!strcmp(msgin.tsp_name, hostname)
273 && msgin.tsp_type != TSP_SETDATE
274 && msgin.tsp_type != TSP_TEST
275 && msgin.tsp_type != TSP_MSITE
276 && msgin.tsp_type != TSP_TRACEON
277 && msgin.tsp_type != TSP_TRACEOFF
278 && msgin.tsp_type != TSP_LOOP) {
280 fprintf(fd, "readmsg: discard own ");
281 print(&msgin, &from);
287 * Send acknowledgements here; this is faster and
288 * avoids deadlocks that would occur if acks were
289 * sent from a higher level routine. Different
290 * acknowledgements are necessary, depending on
293 if (fromnet == NULL) /* do not de-reference 0 */
295 else if (fromnet->status == MASTER)
297 else if (fromnet->status == SLAVE)
302 if (LOOKAT(msgin, type, machfrom, netfrom, from)) {
304 fprintf(fd, "readmsg: ");
305 print(&msgin, &from);
308 } else if (++msgcnt > NHOSTS*3) {
310 /* The protocol gets hopelessly confused if it gets too far
311 * behind. However, it seems able to recover from all cases of lost
312 * packets. Therefore, if we are swamped, throw everything away.
316 "readmsg: discarding %d msgs\n",
319 while ((ptr=head->p) != NULL) {
325 tail->p = (struct tsplist *)
326 malloc(sizeof(struct tsplist));
331 /* timestamp msgs so SETTIMEs are correct */
332 tail->when = from_when;
338 * Send the necessary acknowledgements:
339 * only the type ACK is to be sent by a slave
345 switch(msgin.tsp_type) {
355 fprintf(fd, "Slaveack: ");
356 print(&msgin, &from);
358 xmit(TSP_ACK,msgin.tsp_seq, &from);
363 fprintf(fd, "Slaveack: no ack: ");
364 print(&msgin, &from);
371 * Certain packets may arrive from this machine on ignored networks.
372 * These packets should be acknowledged.
378 switch(msgin.tsp_type) {
384 fprintf(fd, "Ignoreack: ");
385 print(&msgin, &from);
387 xmit(TSP_ACK,msgin.tsp_seq, &from);
392 fprintf(fd, "Ignoreack: no ack: ");
393 print(&msgin, &from);
400 * `masterack' sends the necessary acknowledgments
401 * to the messages received by a master
409 resp.tsp_vers = TSPVERSION;
410 strlcpy(resp.tsp_name, hostname, sizeof(resp.tsp_name));
412 switch(msgin.tsp_type) {
419 fprintf(fd, "Masterack: ");
420 print(&msgin, &from);
422 xmit(TSP_ACK,msgin.tsp_seq, &from);
428 fprintf(fd, "Masterack: ");
429 print(&msgin, &from);
431 xmit(TSP_MASTERACK,msgin.tsp_seq, &from);
436 fprintf(fd,"Masterack: no ack: ");
437 print(&msgin, &from);
444 * Print a TSP message
447 print(struct tsp *msg, struct sockaddr_in *addr)
452 if (msg->tsp_type >= TSPTYPENUMBER) {
453 fprintf(fd, "bad type (%u) on packet from %s\n",
454 msg->tsp_type, inet_ntoa(addr->sin_addr));
458 switch (msg->tsp_type) {
461 fprintf(fd, "%s %d %-6u #%d %-15s %s\n",
462 tsptype[msg->tsp_type],
466 inet_ntoa(addr->sin_addr),
473 tsp_time_sec = msg->tsp_time.tv_sec;
474 strlcpy(tm, ctime(&tsp_time_sec)+3+1, sizeof(tm));
475 fprintf(fd, "%s %d %-6u %s %-15s %s\n",
476 tsptype[msg->tsp_type],
480 inet_ntoa(addr->sin_addr),
485 fprintf(fd, "%s %d %-6u (%ld,%ld) %-15s %s\n",
486 tsptype[msg->tsp_type],
489 msg->tsp_time.tv_sec,
490 msg->tsp_time.tv_usec,
491 inet_ntoa(addr->sin_addr),
496 fprintf(fd, "%s %d %-6u %-15s %s\n",
497 tsptype[msg->tsp_type],
500 inet_ntoa(addr->sin_addr),