tproxy: add lookup type checks for UDP in nf_tproxy_get_sock_v4()
Also, inline this function as the lookup_type is always a literal and inlining removes branches performed at runtime. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
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@ -13,11 +13,123 @@
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#define NFT_LOOKUP_ESTABLISHED 2
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#define NFT_LOOKUP_ESTABLISHED 2
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/* look up and get a reference to a matching socket */
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/* look up and get a reference to a matching socket */
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extern struct sock *
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/* This function is used by the 'TPROXY' target and the 'socket'
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* match. The following lookups are supported:
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*
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* Explicit TProxy target rule
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* ===========================
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*
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* This is used when the user wants to intercept a connection matching
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* an explicit iptables rule. In this case the sockets are assumed
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* matching in preference order:
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*
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* - match: if there's a fully established connection matching the
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* _packet_ tuple, it is returned, assuming the redirection
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* already took place and we process a packet belonging to an
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* established connection
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*
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* - match: if there's a listening socket matching the redirection
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* (e.g. on-port & on-ip of the connection), it is returned,
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* regardless if it was bound to 0.0.0.0 or an explicit
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* address. The reasoning is that if there's an explicit rule, it
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* does not really matter if the listener is bound to an interface
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* or to 0. The user already stated that he wants redirection
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* (since he added the rule).
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*
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* "socket" match based redirection (no specific rule)
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* ===================================================
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*
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* There are connections with dynamic endpoints (e.g. FTP data
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* connection) that the user is unable to add explicit rules
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* for. These are taken care of by a generic "socket" rule. It is
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* assumed that the proxy application is trusted to open such
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* connections without explicit iptables rule (except of course the
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* generic 'socket' rule). In this case the following sockets are
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* matched in preference order:
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*
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* - match: if there's a fully established connection matching the
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* _packet_ tuple
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*
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* - match: if there's a non-zero bound listener (possibly with a
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* non-local address) We don't accept zero-bound listeners, since
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* then local services could intercept traffic going through the
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* box.
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*
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* Please note that there's an overlap between what a TPROXY target
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* and a socket match will match. Normally if you have both rules the
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* "socket" match will be the first one, effectively all packets
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* belonging to established connections going through that one.
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*/
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static inline struct sock *
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nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
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nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
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const __be32 saddr, const __be32 daddr,
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const __be32 saddr, const __be32 daddr,
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const __be16 sport, const __be16 dport,
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const __be16 sport, const __be16 dport,
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const struct net_device *in, int lookup_type);
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const struct net_device *in, int lookup_type)
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{
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struct sock *sk;
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/* look up socket */
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switch (protocol) {
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case IPPROTO_TCP:
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switch (lookup_type) {
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case NFT_LOOKUP_ANY:
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sk = __inet_lookup(net, &tcp_hashinfo,
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saddr, sport, daddr, dport,
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in->ifindex);
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break;
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case NFT_LOOKUP_LISTENER:
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sk = inet_lookup_listener(net, &tcp_hashinfo,
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daddr, dport,
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in->ifindex);
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/* NOTE: we return listeners even if bound to
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* 0.0.0.0, those are filtered out in
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* xt_socket, since xt_TPROXY needs 0 bound
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* listeners too */
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break;
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case NFT_LOOKUP_ESTABLISHED:
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sk = inet_lookup_established(net, &tcp_hashinfo,
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saddr, sport, daddr, dport,
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in->ifindex);
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break;
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default:
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WARN_ON(1);
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sk = NULL;
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break;
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}
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break;
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case IPPROTO_UDP:
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sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
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in->ifindex);
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if (sk && lookup_type != NFT_LOOKUP_ANY) {
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int connected = (sk->sk_state == TCP_ESTABLISHED);
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int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0);
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/* NOTE: we return listeners even if bound to
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* 0.0.0.0, those are filtered out in
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* xt_socket, since xt_TPROXY needs 0 bound
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* listeners too */
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if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
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(lookup_type == NFT_LOOKUP_LISTENER && connected)) {
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sock_put(sk);
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sk = NULL;
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}
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}
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break;
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default:
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WARN_ON(1);
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sk = NULL;
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}
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pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
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protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
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return sk;
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}
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static inline void
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static inline void
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nf_tproxy_put_sock(struct sock *sk)
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nf_tproxy_put_sock(struct sock *sk)
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@ -18,54 +18,6 @@
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#include <net/udp.h>
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#include <net/udp.h>
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#include <net/netfilter/nf_tproxy_core.h>
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#include <net/netfilter/nf_tproxy_core.h>
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struct sock *
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nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
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const __be32 saddr, const __be32 daddr,
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const __be16 sport, const __be16 dport,
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const struct net_device *in, int lookup_type)
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{
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struct sock *sk;
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/* look up socket */
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switch (protocol) {
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case IPPROTO_TCP:
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switch (lookup_type) {
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case NFT_LOOKUP_ANY:
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sk = __inet_lookup(net, &tcp_hashinfo,
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saddr, sport, daddr, dport,
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in->ifindex);
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break;
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case NFT_LOOKUP_LISTENER:
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sk = inet_lookup_listener(net, &tcp_hashinfo,
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daddr, dport,
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in->ifindex);
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break;
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case NFT_LOOKUP_ESTABLISHED:
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sk = inet_lookup_established(net, &tcp_hashinfo,
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saddr, sport, daddr, dport,
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in->ifindex);
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break;
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default:
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WARN_ON(1);
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sk = NULL;
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break;
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}
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break;
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case IPPROTO_UDP:
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sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
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in->ifindex);
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break;
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default:
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WARN_ON(1);
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sk = NULL;
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}
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pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
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protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
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return sk;
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}
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EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v4);
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static void
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static void
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nf_tproxy_destructor(struct sk_buff *skb)
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nf_tproxy_destructor(struct sk_buff *skb)
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