docsis20_stresstest Test Failure

[rlaager]

The docsis20_stresstest is the only test failing for me at the moment.

Debugging with this:

diff --git a/examples/Makefile.am b/examples/Makefile.am
index 9fa000f..2802883 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -46,6 +46,7 @@ EXTRA_DIST = $(examples_DATA)
 			rm -f $@.1.txt $@.2.txt ; \
 			true ; \
 		else \
+			diff -u $@.1.txt $@.2.txt ; \
 			rm -f $@ $@.1.txt $@.2.txt ; \
 			false ; \
 		fi

I get this:

$ make docsis20_stresstest.bin
export MIBDIRS="../mibs:../mibs/iana:../mibs/ietf" ; \
	../src/docsis -e docsis20_stresstest.cfg ./keyfile docsis20_stresstest.bin | \
	sed -n '/^Final content/,$p' | grep -v "^Final content" > docsis20_stresstest.bin.1.txt ; \
	../src/docsis -d docsis20_stresstest.bin > docsis20_stresstest.bin.2.txt ; \
	if cmp docsis20_stresstest.bin.1.txt docsis20_stresstest.bin.2.txt && cmp docsis20_stresstest.txt docsis20_stresstest.bin.2.txt ; then \
		rm -f docsis20_stresstest.bin.1.txt docsis20_stresstest.bin.2.txt ; \
		true ; \
	else \
		diff -u docsis20_stresstest.bin.1.txt docsis20_stresstest.bin.2.txt ; \
		rm -f docsis20_stresstest.bin docsis20_stresstest.bin.1.txt docsis20_stresstest.bin.2.txt ; \
		false ; \
	fi
docsis20_stresstest.bin.1.txt docsis20_stresstest.bin.2.txt differ: byte 12732, line 248
--- docsis20_stresstest.bin.1.txt	2016-11-01 14:06:01.279254714 -0500
+++ docsis20_stresstest.bin.2.txt	2016-11-01 14:06:01.407256201 -0500
@@ -245,5 +245,5 @@
 		ConcatenationSupport 204;
 	}
 	GenericTLV TlvCode 220 TlvLength 173 TlvValue 0x900c95015f66b4fb337408b5cc02de90450fb7d34a4c717430e0170b87356c641a42448297e9ccb76d5b7bbd601ba2fa7703ce3dd4ae038a4f67a5b733d8f1226a452d46950309e0e5a3a70a79ee593858d4d09b8437ab4577149afdccbab17d54a6a84cef9dd57be0c21e5664c2c3bc53836a2f84358cfae1f753a71c6263fc5609458b27728e317e406d6bcae820613d2ec5134b85a4e6ee10b34ec72f2b08663538d4c5cb17cf87e321041d;
-	GenericTLV TlvCode 153 TlvLength 77 TlvValue 0xef12017f0610cedde9cd7a34f366e172cf12f86bb52307104ba4e296c6f9aef93b83ae0dc5a2877cff000000000000000000000000000000000000000000000000000000000000000000000000;
+	GenericTLV TlvCode 153 TlvLength 77 TlvValue 0xef12017f0610cedde9cd7a34f366e172cf12f86bb52307104ba4e296c6f9aef93b83ae0dc5a2877cff0020020000000000006101000000000000c8fc7957027f0000c8fc7957027f0000400200;
 }

[rlaager]

@AdrianSimionov do you have any ideas here? Note that one ends with all zeros, and the other doesn't. Could this be some buffer not being zeroed before use?

[AdrianSimionov]

The problem is:

SnmpMibObject enterprises.1.2.3.4 String "aaaaaaaaabbbaaaaaaaaaaaaaabcdefghijklmnoprstuvwzabcdefghijklmnoprstuvwyzabcdefghijklmnoprstxxxxxxxaaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";

If you remove exactly one character, the test will pass. I think someone put just one extra character to make this test fail on purpose.

The GenericTLVs being different is just a side effect as the tool does not recognise anymore the format and translates everything to GenericTLVs.

[rlaager]

The off-by-one thing makes me even more concerned that we have a buffer problem somewhere. We need to find and fix this one.

[AdrianSimionov]

I will look more into it, I have the feeling there is a buffer overflow somewhere. It might as well be in net-snmp library.