On 2020-06-04 13:03, Steve Grubb wrote: > On Thursday, June 4, 2020 9:20:49 AM EDT Richard Guy Briggs 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: > > v3: > > - inline message type rather than table > > > > 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 | 18 ++++++++ > > kernel/auditsc.c | 24 ++++++++-- > > net/netfilter/nf_tables_api.c | 103 > > ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 142 > > insertions(+), 3 deletions(-) > > > > diff --git a/include/linux/audit.h b/include/linux/audit.h > > index 3fcd9ee49734..604ede630580 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 +99,23 @@ 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, > > }; > > > > extern int is_audit_feature_set(int which); > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c > > index 468a23390457..3a9100e95fda 100644 > > --- a/kernel/auditsc.c > > +++ b/kernel/auditsc.c > > @@ -75,6 +75,7 @@ > > #include <linux/uaccess.h> > > #include <linux/fsnotify_backend.h> > > #include <uapi/linux/limits.h> > > +#include <uapi/linux/netfilter/nf_tables.h> > > > > #include "audit.h" > > > > @@ -136,9 +137,26 @@ struct audit_nfcfgop_tab { > > }; > > > > static const struct audit_nfcfgop_tab audit_nfcfgs[] = { > > - { AUDIT_XT_OP_REGISTER, "register" }, > > - { AUDIT_XT_OP_REPLACE, "replace" }, > > - { AUDIT_XT_OP_UNREGISTER, "unregister" }, > > + { AUDIT_XT_OP_REGISTER, "xt_register" > }, > > + { AUDIT_XT_OP_REPLACE, "xt_replace" }, > > + { AUDIT_XT_OP_UNREGISTER, "xt_unregister" }, > > + { AUDIT_NFT_OP_TABLE_REGISTER, "nft_register_table" > }, > > + { AUDIT_NFT_OP_TABLE_UNREGISTER, "nft_unregister_table" }, > > + { AUDIT_NFT_OP_CHAIN_REGISTER, "nft_register_chain" > }, > > + { AUDIT_NFT_OP_CHAIN_UNREGISTER, "nft_unregister_chain" }, > > + { AUDIT_NFT_OP_RULE_REGISTER, "nft_register_rule" > }, > > + { AUDIT_NFT_OP_RULE_UNREGISTER, "nft_unregister_rule" > }, > > + { AUDIT_NFT_OP_SET_REGISTER, "nft_register_set" > }, > > + { AUDIT_NFT_OP_SET_UNREGISTER, "nft_unregister_set" > }, > > + { AUDIT_NFT_OP_SETELEM_REGISTER, "nft_register_setelem" }, > > + { AUDIT_NFT_OP_SETELEM_UNREGISTER, "nft_unregister_setelem" }, > > + { AUDIT_NFT_OP_GEN_REGISTER, "nft_register_gen" }, > > + { AUDIT_NFT_OP_OBJ_REGISTER, "nft_register_obj" }, > > + { AUDIT_NFT_OP_OBJ_UNREGISTER, "nft_unregister_obj" }, > > + { AUDIT_NFT_OP_OBJ_RESET, "nft_reset_obj" }, > > + { AUDIT_NFT_OP_FLOWTABLE_REGISTER, "nft_register_flowtable" }, > > + { AUDIT_NFT_OP_FLOWTABLE_UNREGISTER, "nft_unregister_flowtable" }, > > + { AUDIT_NFT_OP_INVALID, "nft_invalid" > }, > > }; > > I still don't like the event format because it doesn't give complete subject > information. However, I thought I'd comment on this string table. Usually > it's sufficient to log the number and then have the string table in user space > which looks it up during interpretation. That is a good idea that would help reduce kernel cycles and netlink bandwidth, but the format was set in 2011 so it is a bit late to change that now: fbabf31e4d48 ("netfilter: create audit records for x_tables replaces") > -Steve > > > 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 3558e76e2733..b9e7440cc87d 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 +694,16 @@ 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, > > + event == NFT_MSG_NEWTABLE ? > > + AUDIT_NFT_OP_TABLE_REGISTER : > > + AUDIT_NFT_OP_TABLE_UNREGISTER); > > + kfree(buf); > > > > if (!ctx->report && > > !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) > > @@ -1428,6 +1439,17 @@ static void nf_tables_chain_notify(const struct > > nft_ctx *ctx, int event) { > > struct sk_buff *skb; > > int err; > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", > > + ctx->table->name, ctx->table->handle, > > + ctx->chain->name, ctx->chain->handle); > > + > > + audit_log_nfcfg(buf, > > + ctx->family, > > + ctx->chain->use, > > + event == NFT_MSG_NEWCHAIN ? > > + AUDIT_NFT_OP_CHAIN_REGISTER : > > + AUDIT_NFT_OP_CHAIN_UNREGISTER); > > + kfree(buf); > > > > if (!ctx->report && > > !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) > > @@ -2691,6 +2713,17 @@ static void nf_tables_rule_notify(const struct > > nft_ctx *ctx, { > > struct sk_buff *skb; > > int err; > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", > > + ctx->table->name, ctx->table->handle, > > + ctx->chain->name, ctx->chain->handle); > > + > > + audit_log_nfcfg(buf, > > + ctx->family, > > + rule->handle, > > + event == NFT_MSG_NEWRULE ? > > + AUDIT_NFT_OP_RULE_REGISTER : > > + AUDIT_NFT_OP_RULE_UNREGISTER); > > + kfree(buf); > > > > if (!ctx->report && > > !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) > > @@ -3693,6 +3726,17 @@ static void nf_tables_set_notify(const struct > > nft_ctx *ctx, struct sk_buff *skb; > > u32 portid = ctx->portid; > > int err; > > + char *buf = kasprintf(gfp_flags, "%s:%llu;%s:%llu", > > + ctx->table->name, ctx->table->handle, > > + set->name, set->handle); > > + > > + audit_log_nfcfg(buf, > > + ctx->family, > > + set->field_count, > > + event == NFT_MSG_NEWSET ? > > + AUDIT_NFT_OP_SET_REGISTER : > > + AUDIT_NFT_OP_SET_UNREGISTER); > > + kfree(buf); > > > > if (!ctx->report && > > !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) > > @@ -4809,6 +4853,17 @@ static void nf_tables_setelem_notify(const struct > > nft_ctx *ctx, u32 portid = ctx->portid; > > struct sk_buff *skb; > > int err; > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", > > + ctx->table->name, ctx->table->handle, > > + set->name, set->handle); > > + > > + audit_log_nfcfg(buf, > > + ctx->family, > > + set->handle, > > + event == NFT_MSG_NEWSETELEM ? > > + AUDIT_NFT_OP_SETELEM_REGISTER : > > + AUDIT_NFT_OP_SETELEM_UNREGISTER); > > + kfree(buf); > > > > if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) > > return; > > @@ -5890,6 +5945,19 @@ static int nf_tables_dump_obj(struct sk_buff *skb, > > struct netlink_callback *cb) obj->ops->type->type != filter->type) > > goto cont; > > > > + if (reset) { > > + char *buf = kasprintf(GFP_KERNEL, > > + "%s:%llu;?:0", > > + table->name, > > + table->handle); > > + > > + audit_log_nfcfg(buf, > > + family, > > + obj->handle, > > + AUDIT_NFT_OP_OBJ_RESET); > > + kfree(buf); > > + } > > + > > if (nf_tables_fill_obj_info(skb, net, NETLINK_CB(cb- > >skb).portid, > > cb->nlh->nlmsg_seq, > > NFT_MSG_NEWOBJ, > > @@ -6000,6 +6068,17 @@ static int nf_tables_getobj(struct net *net, struct > > sock *nlsk, if (NFNL_MSG_TYPE(nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET) > > reset = true; > > > > + if (reset) { > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", > > + table->name, table->handle); > > + > > + audit_log_nfcfg(buf, > > + family, > > + obj->handle, > > + AUDIT_NFT_OP_OBJ_RESET); > > + kfree(buf); > > + } > > + > > err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid, > > nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0, > > family, table, obj, reset); > > @@ -6075,6 +6154,16 @@ void nft_obj_notify(struct net *net, const struct > > nft_table *table, { > > struct sk_buff *skb; > > int err; > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0", > > + table->name, table->handle); > > + > > + audit_log_nfcfg(buf, > > + family, > > + obj->handle, > > + event == NFT_MSG_NEWOBJ ? > > + AUDIT_NFT_OP_OBJ_REGISTER : > > + AUDIT_NFT_OP_OBJ_UNREGISTER); > > + kfree(buf); > > > > if (!report && > > !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) > > @@ -6701,6 +6790,17 @@ static void nf_tables_flowtable_notify(struct > > nft_ctx *ctx, { > > struct sk_buff *skb; > > int err; > > + char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu", > > + flowtable->table->name, flowtable->table->handle, > > + flowtable->name, flowtable->handle); > > + > > + audit_log_nfcfg(buf, > > + ctx->family, > > + flowtable->hooknum, > > + event == NFT_MSG_NEWFLOWTABLE ? > > + AUDIT_NFT_OP_FLOWTABLE_REGISTER : > > + AUDIT_NFT_OP_FLOWTABLE_UNREGISTER); > > + kfree(buf); > > > > if (ctx->report && > > !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES)) > > @@ -6822,6 +6922,9 @@ static void nf_tables_gen_notify(struct net *net, > > struct sk_buff *skb, struct sk_buff *skb2; > > int err; > > > > + audit_log_nfcfg("?:0;?:0", 0, net->nft.base_seq, > > + AUDIT_NFT_OP_GEN_REGISTER); > > + > > if (nlmsg_report(nlh) && > > !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES)) > > return; > > > > - 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
