netfilter: nf_nat_snmp_basic: use asn1 decoder library

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The basic SNMP ALG parse snmp ASN.1 payload
however, since 2012 linux kernel provide ASN.1 decoder library.
If we use ASN.1 decoder in the /lib/asn1_decoder.c, we can remove
about 1000 line of ASN.1 parsing routine.

To use asn1_decoder.c, we should write mib file(nf_nat_snmp_basic.asn1)
then /script/asn1_compiler.c makes *-asn1.c and *-asn1.h file
at the compiletime.(nf_nat_snmp_basic-asn1.c, nf_nat_snmp_basic-asn1.h)
The nf_nat_snmp_basic.asn1 is made by RFC1155, RFC1157, RFC1902, RFC1905,
RFC2578, RFC3416. of course that mib file supports only the basic SNMP ALG.

Previous SNMP ALG mangles only first octet of IPv4 address.
but after this patch, the SNMP ALG mangles whole IPv4 Address.
And SNMPv3 is not supported.

I tested with snmp commands such ans snmpd, snmpwalk, snmptrap.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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This commit is contained in:

Taehee Yoo 2018-01-08 00:10:33 +09:00 • committed by Pablo Neira Ayuso

parent bea588b028

commit cc2d58634e

5 changed files with 419 additions and 1192 deletions

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1

net/ipv4/netfilter/Kconfig

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6

net/ipv4/netfilter/Makefile

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177

net/ipv4/netfilter/nf_nat_snmp_basic.asn1

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1192

net/ipv4/netfilter/nf_nat_snmp_basic.c

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235

net/ipv4/netfilter/nf_nat_snmp_basic_main.c

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