From 554ced0a6e2946562c20d9fffdbaf2aa7da36b1b Mon Sep 17 00:00:00 2001 From: Máté Eckl Date: Mon, 28 May 2018 09:15:33 +0200 Subject: netfilter: nf_tables: add support for native socket matching MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now it can only match the transparent flag of an ip/ipv6 socket. Signed-off-by: Máté Eckl Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 9c71f024f9cc..3d46c82a5ebd 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -904,6 +904,31 @@ enum nft_rt_attributes { }; #define NFTA_RT_MAX (__NFTA_RT_MAX - 1) +/** + * enum nft_socket_attributes - nf_tables socket expression netlink attributes + * + * @NFTA_SOCKET_KEY: socket key to match + * @NFTA_SOCKET_DREG: destination register + */ +enum nft_socket_attributes { + NFTA_SOCKET_UNSPEC, + NFTA_SOCKET_KEY, + NFTA_SOCKET_DREG, + __NFTA_SOCKET_MAX +}; +#define NFTA_SOCKET_MAX (__NFTA_SOCKET_MAX - 1) + +/* + * enum nft_socket_keys - nf_tables socket expression keys + * + * @NFT_SOCKET_TRANSPARENT: Value of the IP(V6)_TRANSPARENT socket option_ + */ +enum nft_socket_keys { + NFT_SOCKET_TRANSPARENT, + __NFT_SOCKET_MAX +}; +#define NFT_SOCKET_MAX (__NFT_SOCKET_MAX - 1) + /** * enum nft_ct_keys - nf_tables ct expression keys * -- cgit v1.2.3 From 1a893b44de4528887e7dabcdce7151ca2a8ee238 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Wed, 30 May 2018 11:06:22 +0200 Subject: netfilter: nf_tables: Add audit support to log statement This extends log statement to support the behaviour achieved with AUDIT target in iptables. Audit logging is enabled via a pseudo log level 8. In this case any other settings like log prefix are ignored since audit log format is fixed. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 5 ++ net/netfilter/nft_log.c | 92 +++++++++++++++++++++++++++++++- 2 files changed, 96 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 3d46c82a5ebd..5c7eb9b9f6d6 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -1080,6 +1080,11 @@ enum nft_log_attributes { }; #define NFTA_LOG_MAX (__NFTA_LOG_MAX - 1) +/** + * LOGLEVEL_AUDIT - a pseudo log level enabling audit logging + */ +#define LOGLEVEL_AUDIT 8 + /** * enum nft_queue_attributes - nf_tables queue expression netlink attributes * diff --git a/net/netfilter/nft_log.c b/net/netfilter/nft_log.c index a27be36dc0af..7eef1cffbf1b 100644 --- a/net/netfilter/nft_log.c +++ b/net/netfilter/nft_log.c @@ -9,12 +9,15 @@ * Development of this code funded by Astaro AG (http://www.astaro.com/) */ +#include #include #include #include #include #include #include +#include +#include #include #include #include @@ -26,12 +29,93 @@ struct nft_log { char *prefix; }; +static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) +{ + struct iphdr _iph; + const struct iphdr *ih; + + ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph); + if (!ih) + return false; + + audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", + &ih->saddr, &ih->daddr, ih->protocol); + + return true; +} + +static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb) +{ + struct ipv6hdr _ip6h; + const struct ipv6hdr *ih; + u8 nexthdr; + __be16 frag_off; + + ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h); + if (!ih) + return false; + + nexthdr = ih->nexthdr; + ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off); + + audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", + &ih->saddr, &ih->daddr, nexthdr); + + return true; +} + +static void nft_log_eval_audit(const struct nft_pktinfo *pkt) +{ + struct sk_buff *skb = pkt->skb; + struct audit_buffer *ab; + int fam = -1; + + if (!audit_enabled) + return; + + ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT); + if (!ab) + return; + + audit_log_format(ab, "mark=%#x", skb->mark); + + switch (nft_pf(pkt)) { + case NFPROTO_BRIDGE: + switch (eth_hdr(skb)->h_proto) { + case htons(ETH_P_IP): + fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; + break; + case htons(ETH_P_IPV6): + fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; + break; + } + break; + case NFPROTO_IPV4: + fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; + break; + case NFPROTO_IPV6: + fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; + break; + } + + if (fam == -1) + audit_log_format(ab, " saddr=? daddr=? proto=-1"); + + audit_log_end(ab); +} + static void nft_log_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { const struct nft_log *priv = nft_expr_priv(expr); + if (priv->loginfo.type == NF_LOG_TYPE_LOG && + priv->loginfo.u.log.level == LOGLEVEL_AUDIT) { + nft_log_eval_audit(pkt); + return; + } + nf_log_packet(nft_net(pkt), nft_pf(pkt), nft_hook(pkt), pkt->skb, nft_in(pkt), nft_out(pkt), &priv->loginfo, "%s", priv->prefix); @@ -84,7 +168,7 @@ static int nft_log_init(const struct nft_ctx *ctx, } else { li->u.log.level = LOGLEVEL_WARNING; } - if (li->u.log.level > LOGLEVEL_DEBUG) { + if (li->u.log.level > LOGLEVEL_AUDIT) { err = -EINVAL; goto err1; } @@ -112,6 +196,9 @@ static int nft_log_init(const struct nft_ctx *ctx, break; } + if (li->u.log.level == LOGLEVEL_AUDIT) + return 0; + err = nf_logger_find_get(ctx->family, li->type); if (err < 0) goto err1; @@ -133,6 +220,9 @@ static void nft_log_destroy(const struct nft_ctx *ctx, if (priv->prefix != nft_log_null_prefix) kfree(priv->prefix); + if (li->u.log.level == LOGLEVEL_AUDIT) + return; + nf_logger_put(ctx->family, li->type); } -- cgit v1.2.3 From d32de98ea70fe7cf606f3809f0970b31c115764b Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 31 May 2018 01:58:00 +0200 Subject: netfilter: nft_fwd_netdev: allow to forward packets via neighbour layer This allows us to forward packets from the netdev family via neighbour layer, so you don't need an explicit link-layer destination when using this expression from rules. The ttl/hop_limit field is decremented. Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 4 + net/netfilter/nft_fwd_netdev.c | 146 ++++++++++++++++++++++++++++++- 2 files changed, 149 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 5c7eb9b9f6d6..a089af092a29 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -1260,10 +1260,14 @@ enum nft_dup_attributes { * enum nft_fwd_attributes - nf_tables fwd expression netlink attributes * * @NFTA_FWD_SREG_DEV: source register of output interface (NLA_U32: nft_register) + * @NFTA_FWD_SREG_ADDR: source register of destination address (NLA_U32: nft_register) + * @NFTA_FWD_NFPROTO: layer 3 family of source register address (NLA_U32: enum nfproto) */ enum nft_fwd_attributes { NFTA_FWD_UNSPEC, NFTA_FWD_SREG_DEV, + NFTA_FWD_SREG_ADDR, + NFTA_FWD_NFPROTO, __NFTA_FWD_MAX }; #define NFTA_FWD_MAX (__NFTA_FWD_MAX - 1) diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c index ce13a50b9189..8abb9891cdf2 100644 --- a/net/netfilter/nft_fwd_netdev.c +++ b/net/netfilter/nft_fwd_netdev.c @@ -12,8 +12,12 @@ #include #include #include +#include +#include #include #include +#include +#include struct nft_fwd_netdev { enum nft_registers sreg_dev:8; @@ -32,6 +36,8 @@ static void nft_fwd_netdev_eval(const struct nft_expr *expr, static const struct nla_policy nft_fwd_netdev_policy[NFTA_FWD_MAX + 1] = { [NFTA_FWD_SREG_DEV] = { .type = NLA_U32 }, + [NFTA_FWD_SREG_ADDR] = { .type = NLA_U32 }, + [NFTA_FWD_NFPROTO] = { .type = NLA_U32 }, }; static int nft_fwd_netdev_init(const struct nft_ctx *ctx, @@ -62,7 +68,133 @@ nla_put_failure: return -1; } +struct nft_fwd_neigh { + enum nft_registers sreg_dev:8; + enum nft_registers sreg_addr:8; + u8 nfproto; +}; + +static void nft_fwd_neigh_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_fwd_neigh *priv = nft_expr_priv(expr); + void *addr = ®s->data[priv->sreg_addr]; + int oif = regs->data[priv->sreg_dev]; + unsigned int verdict = NF_STOLEN; + struct sk_buff *skb = pkt->skb; + struct net_device *dev; + int neigh_table; + + switch (priv->nfproto) { + case NFPROTO_IPV4: { + struct iphdr *iph; + + if (skb->protocol != htons(ETH_P_IP)) { + verdict = NFT_BREAK; + goto out; + } + if (skb_try_make_writable(skb, sizeof(*iph))) { + verdict = NF_DROP; + goto out; + } + iph = ip_hdr(skb); + ip_decrease_ttl(iph); + neigh_table = NEIGH_ARP_TABLE; + break; + } + case NFPROTO_IPV6: { + struct ipv6hdr *ip6h; + + if (skb->protocol != htons(ETH_P_IPV6)) { + verdict = NFT_BREAK; + goto out; + } + if (skb_try_make_writable(skb, sizeof(*ip6h))) { + verdict = NF_DROP; + goto out; + } + ip6h = ipv6_hdr(skb); + ip6h->hop_limit--; + neigh_table = NEIGH_ND_TABLE; + break; + } + default: + verdict = NFT_BREAK; + goto out; + } + + dev = dev_get_by_index_rcu(nft_net(pkt), oif); + if (dev == NULL) + return; + + skb->dev = dev; + neigh_xmit(neigh_table, dev, addr, skb); +out: + regs->verdict.code = verdict; +} + +static int nft_fwd_neigh_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_fwd_neigh *priv = nft_expr_priv(expr); + unsigned int addr_len; + int err; + + if (!tb[NFTA_FWD_SREG_DEV] || + !tb[NFTA_FWD_SREG_ADDR] || + !tb[NFTA_FWD_NFPROTO]) + return -EINVAL; + + priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]); + priv->sreg_addr = nft_parse_register(tb[NFTA_FWD_SREG_ADDR]); + priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO])); + + switch (priv->nfproto) { + case NFPROTO_IPV4: + addr_len = sizeof(struct in_addr); + break; + case NFPROTO_IPV6: + addr_len = sizeof(struct in6_addr); + break; + default: + return -EOPNOTSUPP; + } + + err = nft_validate_register_load(priv->sreg_dev, sizeof(int)); + if (err < 0) + return err; + + return nft_validate_register_load(priv->sreg_addr, addr_len); +} + +static const struct nft_expr_ops nft_fwd_netdev_ingress_ops; + +static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + struct nft_fwd_neigh *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) || + nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) || + nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto))) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + static struct nft_expr_type nft_fwd_netdev_type; +static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = { + .type = &nft_fwd_netdev_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)), + .eval = nft_fwd_neigh_eval, + .init = nft_fwd_neigh_init, + .dump = nft_fwd_neigh_dump, +}; + static const struct nft_expr_ops nft_fwd_netdev_ops = { .type = &nft_fwd_netdev_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)), @@ -71,10 +203,22 @@ static const struct nft_expr_ops nft_fwd_netdev_ops = { .dump = nft_fwd_netdev_dump, }; +static const struct nft_expr_ops * +nft_fwd_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + if (tb[NFTA_FWD_SREG_ADDR]) + return &nft_fwd_neigh_netdev_ops; + if (tb[NFTA_FWD_SREG_DEV]) + return &nft_fwd_netdev_ops; + + return ERR_PTR(-EOPNOTSUPP); +} + static struct nft_expr_type nft_fwd_netdev_type __read_mostly = { .family = NFPROTO_NETDEV, .name = "fwd", - .ops = &nft_fwd_netdev_ops, + .select_ops = nft_fwd_select_ops, .policy = nft_fwd_netdev_policy, .maxattr = NFTA_FWD_MAX, .owner = THIS_MODULE, -- cgit v1.2.3