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| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 1999-10-25 16:09:45 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 1999-10-25 16:09:45 +0000 |
| commit | 8379ada798138cf6a8a29913ee1413bbde47e0e4 (patch) | |
| tree | a3adfe90c7ebcd4612053e40a25cae4d558f6227 /cpukit/libnetworking | |
| parent | Patch from Charles-Antoine Gauthier <charles.gauthier@iit.nrc.ca> (diff) | |
| download | rtems-8379ada798138cf6a8a29913ee1413bbde47e0e4.tar.bz2 | |
Patch from Eric Norum <eric@cls.usask.ca> to address the following problem
report from Philip A. Prindeville <philipp@zembu.com>:
I was working on a device driver for a certain ethernet chipset that
occassionally wraps in its buffer, and causes a resulting mbuf chain
with only a few dozen bytes in the first mbuf of the chain.
I wouldn't have thought this would be a problem, until I ran some
stress tests that flooded the ethernet receiver with packets and
started to get panics here:
250
251 if (m->m_pkthdr.len < sizeof(struct ip))
252 goto tooshort;
253
254 #ifdef DIAGNOSTIC
255 if (m->m_len < sizeof(struct ip))
256 panic("ipintr mbuf too short");
257 #endif
258
259 if (m->m_len < sizeof (struct ip) &&
260 (m = m_pullup(m, sizeof (struct ip))) == 0) {
261 ipstat.ips_toosmall++;
262 return;
263 }
264 ip = mtod(m, struct ip *);
and the panic was at line 256. But if I #undef'd DIAGNOSTICS,
then the m_pullup() at line 260 does the right thing and the packet
ends up being processed just fine.
So I started wondering, (a) why was the test checking for
something that apparently wasn't a fatal condition but rather
one that is subsequently recovered from a couple of lines later
and (b) why panic as a diagnostic "aid" from a recoverable
condition rather than just (say) log a message to the console?
All of this seems overly severe for no reason that is readily
apparent to me.
Diffstat (limited to 'cpukit/libnetworking')
| -rw-r--r-- | cpukit/libnetworking/netinet/ip_input.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/cpukit/libnetworking/netinet/ip_input.c b/cpukit/libnetworking/netinet/ip_input.c index 4cc141933f..238e10cf6b 100644 --- a/cpukit/libnetworking/netinet/ip_input.c +++ b/cpukit/libnetworking/netinet/ip_input.c @@ -251,7 +251,7 @@ ip_input(struct mbuf *m) if (m->m_pkthdr.len < sizeof(struct ip)) goto tooshort; -#ifdef DIAGNOSTIC +#if defined(DIAGNOSTIC) && defined(ORIGINAL_FREEBSD_CODE) if (m->m_len < sizeof(struct ip)) panic("ipintr mbuf too short"); #endif |