diff options
-rw-r--r-- | include/net/netfilter/nf_tables.h | 32 | ||||
-rw-r--r-- | include/uapi/linux/netfilter/nf_tables.h | 52 | ||||
-rw-r--r-- | include/uapi/linux/netfilter/nfnetlink.h | 2 | ||||
-rw-r--r-- | net/netfilter/Makefile | 2 | ||||
-rw-r--r-- | net/netfilter/nf_tables_api.c | 12 | ||||
-rw-r--r-- | net/netfilter/nf_tables_core.c | 45 | ||||
-rw-r--r-- | net/netfilter/nf_tables_trace.c | 271 | ||||
-rw-r--r-- | net/netfilter/nfnetlink.c | 1 |
8 files changed, 398 insertions, 19 deletions
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 101d7d7ec243..b313cda49194 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -888,6 +888,38 @@ void nft_unregister_chain_type(const struct nf_chain_type *); int nft_register_expr(struct nft_expr_type *); void nft_unregister_expr(struct nft_expr_type *); +int nft_verdict_dump(struct sk_buff *skb, int type, + const struct nft_verdict *v); + +/** + * struct nft_traceinfo - nft tracing information and state + * + * @pkt: pktinfo currently processed + * @basechain: base chain currently processed + * @chain: chain currently processed + * @rule: rule that was evaluated + * @verdict: verdict given by rule + * @type: event type (enum nft_trace_types) + * @packet_dumped: packet headers sent in a previous traceinfo message + * @trace: other struct members are initialised + */ +struct nft_traceinfo { + const struct nft_pktinfo *pkt; + const struct nft_base_chain *basechain; + const struct nft_chain *chain; + const struct nft_rule *rule; + const struct nft_verdict *verdict; + enum nft_trace_types type; + bool packet_dumped; + bool trace; +}; + +void nft_trace_init(struct nft_traceinfo *info, const struct nft_pktinfo *pkt, + const struct nft_verdict *verdict, + const struct nft_chain *basechain); + +void nft_trace_notify(struct nft_traceinfo *info); + #define nft_dereference(p) \ nfnl_dereference(p, NFNL_SUBSYS_NFTABLES) diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 5f3ececf84b3..b48a3ab761f8 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -83,6 +83,7 @@ enum nft_verdicts { * @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, @@ -102,6 +103,7 @@ enum nf_tables_msg_types { NFT_MSG_DELSETELEM, NFT_MSG_NEWGEN, NFT_MSG_GETGEN, + NFT_MSG_TRACE, NFT_MSG_MAX, }; @@ -987,4 +989,54 @@ enum nft_gen_attributes { }; #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 */ diff --git a/include/uapi/linux/netfilter/nfnetlink.h b/include/uapi/linux/netfilter/nfnetlink.h index 354a7e5e50f2..4bb8cb7730e7 100644 --- a/include/uapi/linux/netfilter/nfnetlink.h +++ b/include/uapi/linux/netfilter/nfnetlink.h @@ -22,6 +22,8 @@ enum nfnetlink_groups { #define NFNLGRP_NFTABLES NFNLGRP_NFTABLES NFNLGRP_ACCT_QUOTA, #define NFNLGRP_ACCT_QUOTA NFNLGRP_ACCT_QUOTA + NFNLGRP_NFTRACE, +#define NFNLGRP_NFTRACE NFNLGRP_NFTRACE __NFNLGRP_MAX, }; #define NFNLGRP_MAX (__NFNLGRP_MAX - 1) diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 7638c36b498c..22934846b5d1 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -67,7 +67,7 @@ obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o obj-$(CONFIG_NETFILTER_SYNPROXY) += nf_synproxy_core.o # nf_tables -nf_tables-objs += nf_tables_core.o nf_tables_api.o +nf_tables-objs += nf_tables_core.o nf_tables_api.o nf_tables_trace.o nf_tables-objs += nft_immediate.o nft_cmp.o nft_lookup.o nft_dynset.o nf_tables-objs += nft_bitwise.o nft_byteorder.o nft_payload.o diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 93cc4737018f..c4969a0d54ba 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4446,22 +4446,22 @@ static void nft_verdict_uninit(const struct nft_data *data) } } -static int nft_verdict_dump(struct sk_buff *skb, const struct nft_data *data) +int nft_verdict_dump(struct sk_buff *skb, int type, const struct nft_verdict *v) { struct nlattr *nest; - nest = nla_nest_start(skb, NFTA_DATA_VERDICT); + nest = nla_nest_start(skb, type); if (!nest) goto nla_put_failure; - if (nla_put_be32(skb, NFTA_VERDICT_CODE, htonl(data->verdict.code))) + if (nla_put_be32(skb, NFTA_VERDICT_CODE, htonl(v->code))) goto nla_put_failure; - switch (data->verdict.code) { + switch (v->code) { case NFT_JUMP: case NFT_GOTO: if (nla_put_string(skb, NFTA_VERDICT_CHAIN, - data->verdict.chain->name)) + v->chain->name)) goto nla_put_failure; } nla_nest_end(skb, nest); @@ -4572,7 +4572,7 @@ int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data, err = nft_value_dump(skb, data, len); break; case NFT_DATA_VERDICT: - err = nft_verdict_dump(skb, data); + err = nft_verdict_dump(skb, NFTA_DATA_VERDICT, &data->verdict); break; default: err = -EINVAL; diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index f3695a497408..2395de7c8ab2 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -44,22 +44,36 @@ static struct nf_loginfo trace_loginfo = { }, }; -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, @@ -121,7 +135,9 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv) 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); @@ -151,7 +167,8 @@ next_rule: 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; @@ -161,7 +178,8 @@ next_rule: 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; } @@ -174,7 +192,8 @@ next_rule: 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; @@ -182,7 +201,8 @@ next_rule: 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); @@ -196,7 +216,8 @@ next_rule: 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)); diff --git a/net/netfilter/nf_tables_trace.c b/net/netfilter/nf_tables_trace.c new file mode 100644 index 000000000000..36fd7ad6729a --- /dev/null +++ b/net/netfilter/nf_tables_trace.c @@ -0,0 +1,271 @@ +/* + * (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; +} diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 46453ab318db..28591fa94ba5 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -49,6 +49,7 @@ static const int nfnl_group2type[NFNLGRP_MAX+1] = { [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, [NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES, [NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT, + [NFNLGRP_NFTRACE] = NFNL_SUBSYS_NFTABLES, }; void nfnl_lock(__u8 subsys_id) |