Bug 29867
| Summary: | 4.3 timed master can't sync Red Hat Linux 6.0 box | ||
|---|---|---|---|
| Product: | Base System | Reporter: | Steve Whiteley <stevew> |
| Component: | misc | Assignee: | Kris Kennaway <kris> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | Unspecified | ||
| Hardware: | Any | ||
| OS: | Any | ||
> The problem is that the sizeof(struct tsp) differs on the two systems. > Made the following change in readmsg.c near line 215, which seems to have fixed the problem. > ---------------------------------------------------------------------- > length = sizeof(from); > if ((n = recvfrom(sock, (char *)&msgin, sizeof(struct tsp), 0, > (struct sockaddr*)&from, &length)) < 0) { > syslog(LOG_ERR, "recvfrom: %m"); > exit(1); > } > /* SRW */ > /* Here is a bug: the sizeof(struct tsp) is OS dependent, depending on the > * length of the tsp_name field (MAXHOSTNAMELEN) which is, e.g., 256 for > * FreeBSD 4.3 and 64 for RH Linux 6.0. Keep this as a sanity check, > * but assume that the name field is 64 or larger > */ > if (n < (ssize_t)sizeof(struct tsp) - MAXHOSTNAMELEN + 64) { > /* > if (n < (ssize_t)sizeof(struct tsp)) { > */ > syslog(LOG_NOTICE, > "short packet (%u/%u bytes) from %s", > n, sizeof(struct tsp), > inet_ntoa(from.sin_addr)); > continue; > } I think this is a more complete fix. According to http://sunsite.berkeley.edu/Dienst/UI/2.0/Describe/ncstrl.ucb/CSD-85-250 the original 4.3BSD code had sizeof(tsp.tsp_name) == 32, so that's probably a safe minimum packet size to use. Can you please test? Kris Index: timed/readmsg.c =================================================================== RCS file: /mnt/ncvs/src/usr.sbin/timed/timed/readmsg.c,v retrieving revision 1.7 diff -u -r1.7 readmsg.c --- timed/readmsg.c 2001/01/01 18:43:21 1.7 +++ timed/readmsg.c 2001/08/19 09:14:07 @@ -212,10 +212,15 @@ syslog(LOG_ERR, "recvfrom: %m"); exit(1); } - if (n < (ssize_t)sizeof(struct tsp)) { + /* + * The 4.3BSD protocol spec had a 32-byte tsp_name field, and + * this is still OS-dependent. Demand that the packet is at + * least long enough to hold a 4.3BSD packet. + */ + if (n < (ssize_t)(sizeof(struct tsp) - MAXHOSTNAMELEN + 32)) { syslog(LOG_NOTICE, "short packet (%u/%u bytes) from %s", - n, sizeof(struct tsp), + n, sizeof(struct tsp) - MAXHOSTNAMELEN + 32, inet_ntoa(from.sin_addr)); continue; } Index: timedc/cmds.c =================================================================== RCS file: /mnt/ncvs/src/usr.sbin/timed/timedc/cmds.c,v retrieving revision 1.7 diff -u -r1.7 cmds.c --- timedc/cmds.c 2001/05/09 08:37:18 1.7 +++ timedc/cmds.c 2001/08/19 09:17:16 @@ -332,10 +332,15 @@ warn("recvfrom"); continue; } - if (cc < sizeof(struct tsp)) { + /* + * The 4.3BSD protocol spec had a 32-byte tsp_name field, and + * this is still OS-dependent. Demand that the packet is at + * least long enough to hold a 4.3BSD packet. + */ + if (cc < (sizeof(struct tsp) - MAXHOSTNAMELEN + 32)) { fprintf(stderr, "short packet (%u/%u bytes) from %s\n", - cc, sizeof(struct tsp), + cc, sizeof(struct tsp) - MAXHOSTNAMELEN + 32, inet_ntoa(from.sin_addr)); continue; } @@ -484,9 +489,15 @@ warn("recvfrom"); return; } - if (cc < sizeof(struct tsp)) { - fprintf(stderr, "short pack (%u/%u bytes) from %s\n", - cc, sizeof(struct tsp), inet_ntoa(from.sin_addr)); + /* + * The 4.3BSD protocol spec had a 32-byte tsp_name field, and + * this is still OS-dependent. Demand that the packet is at + * least long enough to hold a 4.3BSD packet. + */ + if (cc < (sizeof(struct tsp) - MAXHOSTNAMELEN + 32)) { + fprintf(stderr, "short packet (%u/%u bytes) from %s\n", + cc, sizeof(struct tsp) - MAXHOSTNAMELEN + 32, + inet_ntoa(from.sin_addr)); return; } bytehostorder(&msg); State Changed From-To: open->analyzed I've developed a patch to correct this. Responsible Changed From-To: freebsd-bugs->kris State Changed From-To: analyzed->closed Patch committed. I'll consult the release engineer about merging this into 4.4. |
Running timed as master, to synchronize a Red Hat Linux 6.0 box. This worked with FBSD3.5, after upgrading to 4.3, got console error "short packet (xx/xx bytes) from keats" (The real message included the byte counts.) There appeared to be no clock sync. Fix: The problem is that the sizeof(struct tsp) differs on the two systems. Made the following change in readmsg.c near line 215, which seems to have fixed the problem. ---------------------------------------------------------------------- length = sizeof(from); if ((n = recvfrom(sock, (char *)&msgin, sizeof(struct tsp), 0, (struct sockaddr*)&from, &length)) < 0) { syslog(LOG_ERR, "recvfrom: %m"); exit(1); } /* SRW */ /* Here is a bug: the sizeof(struct tsp) is OS dependent, depending on the * length of the tsp_name field (MAXHOSTNAMELEN) which is, e.g., 256 for * FreeBSD 4.3 and 64 for RH Linux 6.0. Keep this as a sanity check, * but assume that the name field is 64 or larger */ if (n < (ssize_t)sizeof(struct tsp) - MAXHOSTNAMELEN + 64) { /* if (n < (ssize_t)sizeof(struct tsp)) { */ syslog(LOG_NOTICE, "short packet (%u/%u bytes) from %s", n, sizeof(struct tsp), inet_ntoa(from.sin_addr)); continue; } How-To-Repeat: boot and run