OID handling and SNMP dissector rewrite

The usability objective of this is to be able to filter on values of SNMP variables like: SNMPv2-MIB.sysUpTime == 274602. The other reason behind this work is not to have a dependency on NET-SNMP which depends on the non-GPL compatible OpenSSL. We'll be using libsmi instead.

TO DO

1️⃣ MUST be done before the next release, 2️⃣ SHOULD be there, 3️⃣ MIGHT be there, ✅ It's being DONE already!

• SNMP

  • 1️⃣ testing

    • OctetString Indexes (both implied and not) -- Some RMON tables use them, capture files are welcome

    • ✅ Traps

    • ✅ fuzz testing

    • ✅ willfully malformed oids and stuff like that

      • ✅ review the PROTOS files in SampleCaptures

  • 1️⃣ Fixing

    • It should only warn, (not inhibit decoding) if expects a different integer type (like Integer32 [APPLICATION 2], Timeticks [APPLICATION 3], or Counter32 [APPLICATION 1] and gets an Integer instead [UNIVERSAL 2] (and vice versa). Same for an Opaque,Nsap, IpAddr vs Octetstring as far as the length allow decoding.

    • ✅ Implement other types off indexing (AGREGATE, ...) these show the following error: The COLUMS's parent is not a ROW. This is a BUG! please contact the wireshark developers.

    • ✅ Some OIds have a -2 hfid value, that means they are unregistered, do not use it.

  • 1️⃣ Document (Always remember C is understood by compilers and programmers, people prefers english) !!!!

    • the changes (where?)
    • and add the smi_* tables to the doocbook files

  • de-bugs

    • ✅ new SNMP dissector shows convoluted tree (now it is a little less convoluted 😃 )

    • ❌ SNMP dissector shows a wrong Timestamp when the value is negative (I Won't get it fixed)

    • 3️⃣ SNMP Object Names not displayed in the info column (see bellow)

  • ✅ regenerate the dissector with -T and -X

  • ✅ add trap oids to COL_INFO

  • 3️⃣ add oids to COL_INFO

  • ✅ get the snmp.variable_oid dissector table back to life.

  • ✅ manage columns as well as scalars

  • ✅ put complete information in the labels of the VarBind Items

• COPS

  • 2️⃣ the mapping of OID->attribute in COPS is still incomplete

  • ✅ we are missing the PIBs (like MIBs but for COPS) in the libsmi zipfile

  • 1️⃣ testing

    • fuzz testing
    • willfully malformed oids and stuff like that
• GENERAL

  • ✅ There are oids being registered with long names like "itu-t(0) identified-organization(4) etsi(0) mobileDomain(0) gsm-Network(1) map-ac(0) networkLocUp(1) version3(3)"

  • ✅ get "the whole thing"^tm into nsis

    • ✅ get the mibs into nsis

    • ✅ get the pibs into nsis

  • 2️⃣ protect the code from re-loading MIBS for modules that were already loaded. A Hard one as it would need to "pre-parse" the modules before asking libsmi to load them. I think I'll Document the potential issues and their symptoms instead.

  • ✅ There are some OIDs that attempt to be registered with "funky" oid strings "dop.agreement.2.5.19.1" or "x411.extension-attribute.27" which are not resolvable (these are in #.REGISTER sections in asn2wrs) (x411 and dop are resolved -- StigBjørlykke)

  • ✅ Come up with a list of default MIBs and PIBs (there was a /*comment*/ in the snmp code (now gone with the surrounding code) saying that we should not, should we?)

  • ✅ add libsmi to autoconf

    • ✅ ./configure's --with-libsmi does not take a location as argument, run like: env LDFLAGS='-lsmi -L/base/lib' CFLAGS=-I/base/include ./configure [options]

    • ✅ remove net-snmp from autoconf

  • ✅ add a menu item or preference setting for the smi_modules UAT

    • 2️⃣ add a link (button) for the tables in SNMP and COPS preference tabs

  • 3️⃣ Some OIDs (not from explicitly included MIBs) are added more than once during protocol registration

  • 2️⃣ implement "ALL" modules, i.e. implement file-name globing and use it on libsmi's MIB/PIB path.

  • ✅ Some macros in oids.h are used to replace the obsoleted oid-related calls in oid_resolv.h to_str.h and format-oid.h, it would be nice to actually rewrite the invocations.

  • ✅ have other users of oid_resolv.h get to use the new functions in oids.h

  • 1️⃣ add the following MIBs and PIBs to the zipfile

    • 3️⃣ H.335 http://www.itu.int/rec/T-REC-H.341-199905-I/en

    • ✅ PIBs included in libsmi

-- LuisOntanon

Imported from https://wiki.wireshark.org/Development/SNMP on 2020-08-11 23:13:06 UTC