[PATCH v3] audit: log nftables configuration change events once per table

[Paul Moore]

On Tue, Mar 23, 2021 at 4:05 PM Richard Guy Briggs <rgb at redhat.com> wrote:
>
> Reduce logging of nftables events to a level similar to iptables.
> Restore the table field to list the table, adding the generation.
>
> Indicate the op as the most significant operation in the event.
>
> A couple of sample events:
>
> type=PROCTITLE msg=audit(2021-03-18 09:30:49.801:143) : proctitle=/usr/bin/python3 -s /usr/sbin/firewalld --nofork --nopid
> type=SYSCALL msg=audit(2021-03-18 09:30:49.801:143) : arch=x86_64 syscall=sendmsg success=yes exit=172 a0=0x6 a1=0x7ffdcfcbe650 a2=0x0 a3=0x7ffdcfcbd52c items=0 ppid=1 pid=367 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=roo
> t sgid=root fsgid=root tty=(none) ses=unset comm=firewalld exe=/usr/bin/python3.9 subj=system_u:system_r:firewalld_t:s0 key=(null)
> type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=ipv6 entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=ipv4 entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.801:143) : table=firewalld:2 family=inet entries=1 op=nft_register_table pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
>
> type=PROCTITLE msg=audit(2021-03-18 09:30:49.839:144) : proctitle=/usr/bin/python3 -s /usr/sbin/firewalld --nofork --nopid
> type=SYSCALL msg=audit(2021-03-18 09:30:49.839:144) : arch=x86_64 syscall=sendmsg success=yes exit=22792 a0=0x6 a1=0x7ffdcfcbe650 a2=0x0 a3=0x7ffdcfcbd52c items=0 ppid=1 pid=367 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=r
> oot sgid=root fsgid=root tty=(none) ses=unset comm=firewalld exe=/usr/bin/python3.9 subj=system_u:system_r:firewalld_t:s0 key=(null)
> type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=ipv6 entries=30 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=ipv4 entries=30 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
> type=NETFILTER_CFG msg=audit(2021-03-18 09:30:49.839:144) : table=firewalld:3 family=inet entries=165 op=nft_register_chain pid=367 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
>
> The issue was originally documented in
> https://github.com/linux-audit/audit-kernel/issues/124
>
> Signed-off-by: Richard Guy Briggs <rgb at redhat.com>
> ---
> Changelog:
> v3:
> - fix function braces, reduce parameter scope
> - pre-allocate nft_audit_data per table in step 1, bail on ENOMEM
>
> v2:
> - convert NFT ops to array indicies in nft2audit_op[]
> - use linux lists
> - use functions for each of collection and logging of audit data
> ---
>  include/linux/audit.h         |  28 ++++++
>  net/netfilter/nf_tables_api.c | 160 ++++++++++++++++------------------
>  2 files changed, 105 insertions(+), 83 deletions(-)

...

> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 82b7c1116a85..5fafcf4c13de 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -118,6 +118,34 @@ enum audit_nfcfgop {
>         AUDIT_NFT_OP_INVALID,
>  };
>
> +static const u8 nft2audit_op[NFT_MSG_MAX] = { // enum nf_tables_msg_types
> +       [NFT_MSG_NEWTABLE]      = AUDIT_NFT_OP_TABLE_REGISTER,
> +       [NFT_MSG_GETTABLE]      = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELTABLE]      = AUDIT_NFT_OP_TABLE_UNREGISTER,
> +       [NFT_MSG_NEWCHAIN]      = AUDIT_NFT_OP_CHAIN_REGISTER,
> +       [NFT_MSG_GETCHAIN]      = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELCHAIN]      = AUDIT_NFT_OP_CHAIN_UNREGISTER,
> +       [NFT_MSG_NEWRULE]       = AUDIT_NFT_OP_RULE_REGISTER,
> +       [NFT_MSG_GETRULE]       = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELRULE]       = AUDIT_NFT_OP_RULE_UNREGISTER,
> +       [NFT_MSG_NEWSET]        = AUDIT_NFT_OP_SET_REGISTER,
> +       [NFT_MSG_GETSET]        = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELSET]        = AUDIT_NFT_OP_SET_UNREGISTER,
> +       [NFT_MSG_NEWSETELEM]    = AUDIT_NFT_OP_SETELEM_REGISTER,
> +       [NFT_MSG_GETSETELEM]    = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELSETELEM]    = AUDIT_NFT_OP_SETELEM_UNREGISTER,
> +       [NFT_MSG_NEWGEN]        = AUDIT_NFT_OP_GEN_REGISTER,
> +       [NFT_MSG_GETGEN]        = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_TRACE]         = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_NEWOBJ]        = AUDIT_NFT_OP_OBJ_REGISTER,
> +       [NFT_MSG_GETOBJ]        = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELOBJ]        = AUDIT_NFT_OP_OBJ_UNREGISTER,
> +       [NFT_MSG_GETOBJ_RESET]  = AUDIT_NFT_OP_OBJ_RESET,
> +       [NFT_MSG_NEWFLOWTABLE]  = AUDIT_NFT_OP_FLOWTABLE_REGISTER,
> +       [NFT_MSG_GETFLOWTABLE]  = AUDIT_NFT_OP_INVALID,
> +       [NFT_MSG_DELFLOWTABLE]  = AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
> +};

The previously reported problem with this as a static still exists,
correct?  It does seem like this should live in nf_tables_api.c
doesn't it?

-- 
paul moore
www.paul-moore.com