* @NFT_MSG_DELSETELEM: delete a set element (enum nft_set_elem_attributes)
* @NFT_MSG_NEWGEN: announce a new generation, only for events (enum nft_gen_attributes)
* @NFT_MSG_GETGEN: get the rule-set generation (enum nft_gen_attributes)
+ * @NFT_MSG_TRACE: trace event (enum nft_trace_attributes)
*/
enum nf_tables_msg_types {
NFT_MSG_NEWTABLE,
NFT_MSG_DELSETELEM,
NFT_MSG_NEWGEN,
NFT_MSG_GETGEN,
+ NFT_MSG_TRACE,
NFT_MSG_MAX,
};
};
#define NFTA_GEN_MAX (__NFTA_GEN_MAX - 1)
+/**
+ * enum nft_trace_attributes - nf_tables trace netlink attributes
+ *
+ * @NFTA_TRACE_TABLE: name of the table (NLA_STRING)
+ * @NFTA_TRACE_CHAIN: name of the chain (NLA_STRING)
+ * @NFTA_TRACE_RULE_HANDLE: numeric handle of the rule (NLA_U64)
+ * @NFTA_TRACE_TYPE: type of the event (NLA_U32: nft_trace_types)
+ * @NFTA_TRACE_VERDICT: verdict returned by hook (NLA_NESTED: nft_verdicts)
+ * @NFTA_TRACE_ID: pseudo-id, same for each skb traced (NLA_U32)
+ * @NFTA_TRACE_LL_HEADER: linklayer header (NLA_BINARY)
+ * @NFTA_TRACE_NETWORK_HEADER: network header (NLA_BINARY)
+ * @NFTA_TRACE_TRANSPORT_HEADER: transport header (NLA_BINARY)
+ * @NFTA_TRACE_IIF: indev ifindex (NLA_U32)
+ * @NFTA_TRACE_IIFTYPE: netdev->type of indev (NLA_U16)
+ * @NFTA_TRACE_OIF: outdev ifindex (NLA_U32)
+ * @NFTA_TRACE_OIFTYPE: netdev->type of outdev (NLA_U16)
+ * @NFTA_TRACE_MARK: nfmark (NLA_U32)
+ * @NFTA_TRACE_NFPROTO: nf protocol processed (NLA_U32)
+ * @NFTA_TRACE_POLICY: policy that decided fate of packet (NLA_U32)
+ */
+enum nft_trace_attibutes {
+ NFTA_TRACE_UNSPEC,
+ NFTA_TRACE_TABLE,
+ NFTA_TRACE_CHAIN,
+ NFTA_TRACE_RULE_HANDLE,
+ NFTA_TRACE_TYPE,
+ NFTA_TRACE_VERDICT,
+ NFTA_TRACE_ID,
+ NFTA_TRACE_LL_HEADER,
+ NFTA_TRACE_NETWORK_HEADER,
+ NFTA_TRACE_TRANSPORT_HEADER,
+ NFTA_TRACE_IIF,
+ NFTA_TRACE_IIFTYPE,
+ NFTA_TRACE_OIF,
+ NFTA_TRACE_OIFTYPE,
+ NFTA_TRACE_MARK,
+ NFTA_TRACE_NFPROTO,
+ NFTA_TRACE_POLICY,
+ __NFTA_TRACE_MAX
+};
+#define NFTA_TRACE_MAX (__NFTA_TRACE_MAX - 1)
+
+enum nft_trace_types {
+ NFT_TRACETYPE_UNSPEC,
+ NFT_TRACETYPE_POLICY,
+ NFT_TRACETYPE_RETURN,
+ NFT_TRACETYPE_RULE,
+ __NFT_TRACETYPE_MAX
+};
+#define NFT_TRACETYPE_MAX (__NFT_TRACETYPE_MAX - 1)
#endif /* _LINUX_NF_TABLES_H */
},
};
-static void __nft_trace_packet(const struct nft_pktinfo *pkt,
- const struct nft_chain *chain,
- int rulenum, enum nft_trace type)
+static noinline void __nft_trace_packet(struct nft_traceinfo *info,
+ const struct nft_chain *chain,
+ int rulenum, enum nft_trace type)
{
+ const struct nft_pktinfo *pkt = info->pkt;
+
+ if (!pkt->skb->nf_trace)
+ return;
+
+ info->chain = chain;
+ info->type = type;
+
+ nft_trace_notify(info);
+
nf_log_trace(pkt->net, pkt->pf, pkt->hook, pkt->skb, pkt->in,
pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
chain->table->name, chain->name, comments[type],
rulenum);
}
-static inline void nft_trace_packet(const struct nft_pktinfo *pkt,
+static inline void nft_trace_packet(struct nft_traceinfo *info,
const struct nft_chain *chain,
- int rulenum, enum nft_trace type)
+ const struct nft_rule *rule,
+ int rulenum,
+ enum nft_trace_types type)
{
- if (unlikely(pkt->skb->nf_trace))
- __nft_trace_packet(pkt, chain, rulenum, type);
+ if (unlikely(info->trace)) {
+ info->rule = rule;
+ __nft_trace_packet(info, chain, rulenum, type);
+ }
}
static void nft_cmp_fast_eval(const struct nft_expr *expr,
struct nft_stats *stats;
int rulenum;
unsigned int gencursor = nft_genmask_cur(net);
+ struct nft_traceinfo info;
+ nft_trace_init(&info, pkt, ®s.verdict, basechain);
do_chain:
rulenum = 0;
rule = list_entry(&chain->rules, struct nft_rule, list);
regs.verdict.code = NFT_CONTINUE;
continue;
case NFT_CONTINUE:
- nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE);
+ nft_trace_packet(&info, chain, rule,
+ rulenum, NFT_TRACETYPE_RULE);
continue;
}
break;
case NF_ACCEPT:
case NF_DROP:
case NF_QUEUE:
- nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE);
+ nft_trace_packet(&info, chain, rule,
+ rulenum, NFT_TRACETYPE_RULE);
return regs.verdict.code;
}
stackptr++;
/* fall through */
case NFT_GOTO:
- nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE);
+ nft_trace_packet(&info, chain, rule,
+ rulenum, NFT_TRACETYPE_RULE);
chain = regs.verdict.chain;
goto do_chain;
rulenum++;
/* fall through */
case NFT_RETURN:
- nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RETURN);
+ nft_trace_packet(&info, chain, rule,
+ rulenum, NFT_TRACETYPE_RETURN);
break;
default:
WARN_ON(1);
goto next_rule;
}
- nft_trace_packet(pkt, basechain, -1, NFT_TRACE_POLICY);
+ nft_trace_packet(&info, basechain, NULL, -1,
+ NFT_TRACETYPE_POLICY);
rcu_read_lock_bh();
stats = this_cpu_ptr(rcu_dereference(nft_base_chain(basechain)->stats));
--- /dev/null
+/*
+ * (C) 2015 Red Hat GmbH
+ * Author: Florian Westphal <fw@strlen.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/hash.h>
+#include <linux/jhash.h>
+#include <linux/if_vlan.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_tables.h>
+
+#define NFT_TRACETYPE_LL_HSIZE 20
+#define NFT_TRACETYPE_NETWORK_HSIZE 40
+#define NFT_TRACETYPE_TRANSPORT_HSIZE 20
+
+static int trace_fill_id(struct sk_buff *nlskb, struct sk_buff *skb)
+{
+ __be32 id;
+
+ /* using skb address as ID results in a limited number of
+ * values (and quick reuse).
+ *
+ * So we attempt to use as many skb members that will not
+ * change while skb is with netfilter.
+ */
+ id = (__be32)jhash_2words(hash32_ptr(skb), skb_get_hash(skb),
+ skb->skb_iif);
+
+ return nla_put_be32(nlskb, NFTA_TRACE_ID, id);
+}
+
+static int trace_fill_header(struct sk_buff *nlskb, u16 type,
+ const struct sk_buff *skb,
+ int off, unsigned int len)
+{
+ struct nlattr *nla;
+
+ if (len == 0)
+ return 0;
+
+ nla = nla_reserve(nlskb, type, len);
+ if (!nla || skb_copy_bits(skb, off, nla_data(nla), len))
+ return -1;
+
+ return 0;
+}
+
+static int nf_trace_fill_ll_header(struct sk_buff *nlskb,
+ const struct sk_buff *skb)
+{
+ struct vlan_ethhdr veth;
+ int off;
+
+ BUILD_BUG_ON(sizeof(veth) > NFT_TRACETYPE_LL_HSIZE);
+
+ off = skb_mac_header(skb) - skb->data;
+ if (off != -ETH_HLEN)
+ return -1;
+
+ if (skb_copy_bits(skb, off, &veth, ETH_HLEN))
+ return -1;
+
+ veth.h_vlan_proto = skb->vlan_proto;
+ veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
+ veth.h_vlan_encapsulated_proto = skb->protocol;
+
+ return nla_put(nlskb, NFTA_TRACE_LL_HEADER, sizeof(veth), &veth);
+}
+
+static int nf_trace_fill_dev_info(struct sk_buff *nlskb,
+ const struct net_device *indev,
+ const struct net_device *outdev)
+{
+ if (indev) {
+ if (nla_put_be32(nlskb, NFTA_TRACE_IIF,
+ htonl(indev->ifindex)))
+ return -1;
+
+ if (nla_put_be16(nlskb, NFTA_TRACE_IIFTYPE,
+ htons(indev->type)))
+ return -1;
+ }
+
+ if (outdev) {
+ if (nla_put_be32(nlskb, NFTA_TRACE_OIF,
+ htonl(outdev->ifindex)))
+ return -1;
+
+ if (nla_put_be16(nlskb, NFTA_TRACE_OIFTYPE,
+ htons(outdev->type)))
+ return -1;
+ }
+
+ return 0;
+}
+
+static int nf_trace_fill_pkt_info(struct sk_buff *nlskb,
+ const struct nft_pktinfo *pkt)
+{
+ const struct sk_buff *skb = pkt->skb;
+ unsigned int len = min_t(unsigned int,
+ pkt->xt.thoff - skb_network_offset(skb),
+ NFT_TRACETYPE_NETWORK_HSIZE);
+ int off = skb_network_offset(skb);
+
+ if (trace_fill_header(nlskb, NFTA_TRACE_NETWORK_HEADER, skb, off, len))
+ return -1;
+
+ len = min_t(unsigned int, skb->len - pkt->xt.thoff,
+ NFT_TRACETYPE_TRANSPORT_HSIZE);
+
+ if (trace_fill_header(nlskb, NFTA_TRACE_TRANSPORT_HEADER, skb,
+ pkt->xt.thoff, len))
+ return -1;
+
+ if (!skb_mac_header_was_set(skb))
+ return 0;
+
+ if (skb_vlan_tag_get(skb))
+ return nf_trace_fill_ll_header(nlskb, skb);
+
+ off = skb_mac_header(skb) - skb->data;
+ len = min_t(unsigned int, -off, NFT_TRACETYPE_LL_HSIZE);
+ return trace_fill_header(nlskb, NFTA_TRACE_LL_HEADER,
+ skb, off, len);
+}
+
+static int nf_trace_fill_rule_info(struct sk_buff *nlskb,
+ const struct nft_traceinfo *info)
+{
+ if (!info->rule)
+ return 0;
+
+ /* a continue verdict with ->type == RETURN means that this is
+ * an implicit return (end of chain reached).
+ *
+ * Since no rule matched, the ->rule pointer is invalid.
+ */
+ if (info->type == NFT_TRACETYPE_RETURN &&
+ info->verdict->code == NFT_CONTINUE)
+ return 0;
+
+ return nla_put_be64(nlskb, NFTA_TRACE_RULE_HANDLE,
+ cpu_to_be64(info->rule->handle));
+}
+
+void nft_trace_notify(struct nft_traceinfo *info)
+{
+ const struct nft_pktinfo *pkt = info->pkt;
+ struct nfgenmsg *nfmsg;
+ struct nlmsghdr *nlh;
+ struct sk_buff *skb;
+ unsigned int size;
+ int event = (NFNL_SUBSYS_NFTABLES << 8) | NFT_MSG_TRACE;
+
+ if (!nfnetlink_has_listeners(pkt->net, NFNLGRP_NFTRACE))
+ return;
+
+ size = nlmsg_total_size(sizeof(struct nfgenmsg)) +
+ nla_total_size(NFT_TABLE_MAXNAMELEN) +
+ nla_total_size(NFT_CHAIN_MAXNAMELEN) +
+ nla_total_size(sizeof(__be64)) + /* rule handle */
+ nla_total_size(sizeof(__be32)) + /* trace type */
+ nla_total_size(0) + /* VERDICT, nested */
+ nla_total_size(sizeof(u32)) + /* verdict code */
+ nla_total_size(NFT_CHAIN_MAXNAMELEN) + /* jump target */
+ nla_total_size(sizeof(u32)) + /* id */
+ nla_total_size(NFT_TRACETYPE_LL_HSIZE) +
+ nla_total_size(NFT_TRACETYPE_NETWORK_HSIZE) +
+ nla_total_size(NFT_TRACETYPE_TRANSPORT_HSIZE) +
+ nla_total_size(sizeof(u32)) + /* iif */
+ nla_total_size(sizeof(__be16)) + /* iiftype */
+ nla_total_size(sizeof(u32)) + /* oif */
+ nla_total_size(sizeof(__be16)) + /* oiftype */
+ nla_total_size(sizeof(u32)) + /* mark */
+ nla_total_size(sizeof(u32)) + /* nfproto */
+ nla_total_size(sizeof(u32)); /* policy */
+
+ skb = nlmsg_new(size, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ nlh = nlmsg_put(skb, 0, 0, event, sizeof(struct nfgenmsg), 0);
+ if (!nlh)
+ goto nla_put_failure;
+
+ nfmsg = nlmsg_data(nlh);
+ nfmsg->nfgen_family = info->basechain->type->family;
+ nfmsg->version = NFNETLINK_V0;
+ nfmsg->res_id = 0;
+
+ if (nla_put_be32(skb, NFTA_TRACE_NFPROTO, htonl(pkt->pf)))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NFTA_TRACE_TYPE, htonl(info->type)))
+ goto nla_put_failure;
+
+ if (trace_fill_id(skb, pkt->skb))
+ goto nla_put_failure;
+
+ if (info->chain) {
+ if (nla_put_string(skb, NFTA_TRACE_CHAIN,
+ info->chain->name))
+ goto nla_put_failure;
+ if (nla_put_string(skb, NFTA_TRACE_TABLE,
+ info->chain->table->name))
+ goto nla_put_failure;
+ }
+
+ if (nf_trace_fill_rule_info(skb, info))
+ goto nla_put_failure;
+
+ switch (info->type) {
+ case NFT_TRACETYPE_UNSPEC:
+ case __NFT_TRACETYPE_MAX:
+ break;
+ case NFT_TRACETYPE_RETURN:
+ case NFT_TRACETYPE_RULE:
+ if (nft_verdict_dump(skb, NFTA_TRACE_VERDICT, info->verdict))
+ goto nla_put_failure;
+ break;
+ case NFT_TRACETYPE_POLICY:
+ if (nla_put_be32(skb, NFTA_TRACE_POLICY,
+ info->basechain->policy))
+ goto nla_put_failure;
+ break;
+ }
+
+ if (pkt->skb->mark &&
+ nla_put_be32(skb, NFTA_TRACE_MARK, htonl(pkt->skb->mark)))
+ goto nla_put_failure;
+
+ if (!info->packet_dumped) {
+ if (nf_trace_fill_dev_info(skb, pkt->in, pkt->out))
+ goto nla_put_failure;
+
+ if (nf_trace_fill_pkt_info(skb, pkt))
+ goto nla_put_failure;
+ info->packet_dumped = true;
+ }
+
+ nlmsg_end(skb, nlh);
+ nfnetlink_send(skb, pkt->net, 0, NFNLGRP_NFTRACE, 0, GFP_ATOMIC);
+ return;
+
+ nla_put_failure:
+ WARN_ON_ONCE(1);
+ kfree_skb(skb);
+}
+
+void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt,
+ const struct nft_verdict *verdict,
+ const struct nft_chain *chain)
+{
+ info->basechain = nft_base_chain(chain);
+ info->trace = true;
+ info->packet_dumped = false;
+ info->pkt = pkt;
+ info->verdict = verdict;
+}