On 2020-06-01 12:10, Paul Moore wrote: > On Thu, May 28, 2020 at 9:44 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > > iptables, ip6tables, arptables and ebtables table registration, > > replacement and unregistration configuration events are logged for the > > native (legacy) iptables setsockopt api, but not for the > > nftables netlink api which is used by the nft-variant of iptables in > > addition to nftables itself. > > > > Add calls to log the configuration actions in the nftables netlink api. > > > > This uses the same NETFILTER_CFG record format but overloads the table > > field. > > > > type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=?:0;?:0 family=unspecified entries=2 op=nft_register_gen pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld > > ... > > type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=firewalld:1;?:0 family=inet entries=0 op=nft_register_table pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld > > ... > > type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=8 op=nft_register_chain pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld > > ... > > type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=101 op=nft_register_rule pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld > > ... > > type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=87 op=nft_register_setelem pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld > > ... > > type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=0 op=nft_register_set pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld > > > > For further information please see issue > > https://github.com/linux-audit/audit-kernel/issues/124 > > > > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx> > > --- > > Changelog: > > v2: > > - differentiate between xtables and nftables > > - add set, setelem, obj, flowtable, gen > > - use nentries field as appropriate per type > > - overload the "tables" field with table handle and chain/set/flowtable > > > > include/linux/audit.h | 52 +++++++++++++++++++++++++ > > kernel/auditsc.c | 24 ++++++++++-- > > net/netfilter/nf_tables_api.c | 89 +++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 162 insertions(+), 3 deletions(-) > > > > diff --git a/include/linux/audit.h b/include/linux/audit.h > > index 3fcd9ee49734..d79866a38505 100644 > > --- a/include/linux/audit.h > > +++ b/include/linux/audit.h > > @@ -12,6 +12,7 @@ > > #include <linux/sched.h> > > #include <linux/ptrace.h> > > #include <uapi/linux/audit.h> > > +#include <uapi/linux/netfilter/nf_tables.h> > > > > #define AUDIT_INO_UNSET ((unsigned long)-1) > > #define AUDIT_DEV_UNSET ((dev_t)-1) > > @@ -98,6 +99,57 @@ enum audit_nfcfgop { > > AUDIT_XT_OP_REGISTER, > > AUDIT_XT_OP_REPLACE, > > AUDIT_XT_OP_UNREGISTER, > > + AUDIT_NFT_OP_TABLE_REGISTER, > > + AUDIT_NFT_OP_TABLE_UNREGISTER, > > + AUDIT_NFT_OP_CHAIN_REGISTER, > > + AUDIT_NFT_OP_CHAIN_UNREGISTER, > > + AUDIT_NFT_OP_RULE_REGISTER, > > + AUDIT_NFT_OP_RULE_UNREGISTER, > > + AUDIT_NFT_OP_SET_REGISTER, > > + AUDIT_NFT_OP_SET_UNREGISTER, > > + AUDIT_NFT_OP_SETELEM_REGISTER, > > + AUDIT_NFT_OP_SETELEM_UNREGISTER, > > + AUDIT_NFT_OP_GEN_REGISTER, > > + AUDIT_NFT_OP_OBJ_REGISTER, > > + AUDIT_NFT_OP_OBJ_UNREGISTER, > > + AUDIT_NFT_OP_OBJ_RESET, > > + AUDIT_NFT_OP_FLOWTABLE_REGISTER, > > + AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, > > + AUDIT_NFT_OP_INVALID, > > +}; > > + > > +struct audit_nftcfgop_tab { > > + enum nf_tables_msg_types nftop; > > + enum audit_nfcfgop op; > > +}; > > + > > +static const struct audit_nftcfgop_tab audit_nftcfgs[] = { > > + { 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 }, > > + { NFT_MSG_MAX, AUDIT_NFT_OP_INVALID }, > > }; > > I didn't check every "op" defined above to match with the changes in > nf_tables_api.c, but is there a reason why we can't simply hardcode > the AUDIT_NFT_OP_* values in the audit_log_nfcfg() calls in > nf_tables_api.c? If we can, let's do that. Yes, to distinguish between x/ebtables and nftables. The first three overlap (as suggested by the first comment in the changelog above). > If we can't do that, we need to add some build-time protection to > catch if NFT_MSG_MAX increases without this table being updated. I would have liked to do that, but it would then have meant making a new function name, say audit_log_nftcfg vs the original audit_log_nfcfg so that the overlapping values could be translated appropriately with the correct prefix. Well, considering the buildbot error, I had to restructure it so that the table was moved from include/linux/audit.h to net/netfilter/nf_tables_api.c where it would be a bit more evident. At first I thought the bot was complaining about the first field not being used, but it turned out it was ptrace that was including it and not using it. > > static int audit_match_perm(struct audit_context *ctx, int mask) > > diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c > > index 4471393da6d8..7a386eca6e04 100644 > > --- a/net/netfilter/nf_tables_api.c > > +++ b/net/netfilter/nf_tables_api.c > > @@ -12,6 +12,7 @@ > > #include <linux/netlink.h> > > #include <linux/vmalloc.h> > > #include <linux/rhashtable.h> > > +#include <linux/audit.h> > > #include <linux/netfilter.h> > > #include <linux/netfilter/nfnetlink.h> > > #include <linux/netfilter/nf_tables.h> > > @@ -693,6 +694,14 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event) > > { > > struct sk_buff *skb; > > int err; > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", > > + ctx->table->name, ctx->table->handle); > > + > > + audit_log_nfcfg(buf, > > + ctx->family, > > + ctx->table->use, > > + audit_nftcfgs[event].op); > > As an example, the below would work, yes? > > audit_log_nfcfg(..., > (event == NFT_MSG_NEWTABLE ? > AUDIT_NFT_OP_TABLE_REGISTER : > AUDIT_NFT_OP_TABLE_UNREGISTER) Ok, I see what you are getting at now... Yes, it could be done this way, but it seems noisier to me. > > + kfree(buf); > > > > if (!ctx->report && > > !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) > > paul moore - RGB -- Richard Guy Briggs <rgb@xxxxxxxxxx> Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635
