diff options
Diffstat (limited to 'include/net')
-rw-r--r-- | include/net/inet_hashtables.h | 2 | ||||
-rw-r--r-- | include/net/netfilter/ipv6/nf_defrag_ipv6.h | 6 | ||||
-rw-r--r-- | include/net/netfilter/nf_tproxy_core.h | 192 | ||||
-rw-r--r-- | include/net/udp.h | 3 |
4 files changed, 199 insertions, 4 deletions
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 74358d1b3f43..e9c2ed8af864 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -245,7 +245,7 @@ static inline int inet_sk_listen_hashfn(const struct sock *sk) } /* Caller must disable local BH processing. */ -extern void __inet_inherit_port(struct sock *sk, struct sock *child); +extern int __inet_inherit_port(struct sock *sk, struct sock *child); extern void inet_put_port(struct sock *sk); diff --git a/include/net/netfilter/ipv6/nf_defrag_ipv6.h b/include/net/netfilter/ipv6/nf_defrag_ipv6.h new file mode 100644 index 000000000000..94dd54d76b48 --- /dev/null +++ b/include/net/netfilter/ipv6/nf_defrag_ipv6.h @@ -0,0 +1,6 @@ +#ifndef _NF_DEFRAG_IPV6_H +#define _NF_DEFRAG_IPV6_H + +extern void nf_defrag_ipv6_enable(void); + +#endif /* _NF_DEFRAG_IPV6_H */ diff --git a/include/net/netfilter/nf_tproxy_core.h b/include/net/netfilter/nf_tproxy_core.h index 208b46f4d6d2..cd85b3bc8327 100644 --- a/include/net/netfilter/nf_tproxy_core.h +++ b/include/net/netfilter/nf_tproxy_core.h @@ -5,15 +5,201 @@ #include <linux/in.h> #include <linux/skbuff.h> #include <net/sock.h> -#include <net/inet_sock.h> +#include <net/inet_hashtables.h> +#include <net/inet6_hashtables.h> #include <net/tcp.h> +#define NFT_LOOKUP_ANY 0 +#define NFT_LOOKUP_LISTENER 1 +#define NFT_LOOKUP_ESTABLISHED 2 + /* look up and get a reference to a matching socket */ -extern struct sock * + + +/* This function is used by the 'TPROXY' target and the 'socket' + * match. The following lookups are supported: + * + * Explicit TProxy target rule + * =========================== + * + * This is used when the user wants to intercept a connection matching + * an explicit iptables rule. In this case the sockets are assumed + * matching in preference order: + * + * - match: if there's a fully established connection matching the + * _packet_ tuple, it is returned, assuming the redirection + * already took place and we process a packet belonging to an + * established connection + * + * - match: if there's a listening socket matching the redirection + * (e.g. on-port & on-ip of the connection), it is returned, + * regardless if it was bound to 0.0.0.0 or an explicit + * address. The reasoning is that if there's an explicit rule, it + * does not really matter if the listener is bound to an interface + * or to 0. The user already stated that he wants redirection + * (since he added the rule). + * + * "socket" match based redirection (no specific rule) + * =================================================== + * + * There are connections with dynamic endpoints (e.g. FTP data + * connection) that the user is unable to add explicit rules + * for. These are taken care of by a generic "socket" rule. It is + * assumed that the proxy application is trusted to open such + * connections without explicit iptables rule (except of course the + * generic 'socket' rule). In this case the following sockets are + * matched in preference order: + * + * - match: if there's a fully established connection matching the + * _packet_ tuple + * + * - match: if there's a non-zero bound listener (possibly with a + * non-local address) We don't accept zero-bound listeners, since + * then local services could intercept traffic going through the + * box. + * + * Please note that there's an overlap between what a TPROXY target + * and a socket match will match. Normally if you have both rules the + * "socket" match will be the first one, effectively all packets + * belonging to established connections going through that one. + */ +static inline struct sock * nf_tproxy_get_sock_v4(struct net *net, const u8 protocol, const __be32 saddr, const __be32 daddr, const __be16 sport, const __be16 dport, - const struct net_device *in, bool listening); + const struct net_device *in, int lookup_type) +{ + struct sock *sk; + + /* look up socket */ + switch (protocol) { + case IPPROTO_TCP: + switch (lookup_type) { + case NFT_LOOKUP_ANY: + sk = __inet_lookup(net, &tcp_hashinfo, + saddr, sport, daddr, dport, + in->ifindex); + break; + case NFT_LOOKUP_LISTENER: + sk = inet_lookup_listener(net, &tcp_hashinfo, + daddr, dport, + in->ifindex); + + /* NOTE: we return listeners even if bound to + * 0.0.0.0, those are filtered out in + * xt_socket, since xt_TPROXY needs 0 bound + * listeners too */ + + break; + case NFT_LOOKUP_ESTABLISHED: + sk = inet_lookup_established(net, &tcp_hashinfo, + saddr, sport, daddr, dport, + in->ifindex); + break; + default: + WARN_ON(1); + sk = NULL; + break; + } + break; + case IPPROTO_UDP: + sk = udp4_lib_lookup(net, saddr, sport, daddr, dport, + in->ifindex); + if (sk && lookup_type != NFT_LOOKUP_ANY) { + int connected = (sk->sk_state == TCP_ESTABLISHED); + int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0); + + /* NOTE: we return listeners even if bound to + * 0.0.0.0, those are filtered out in + * xt_socket, since xt_TPROXY needs 0 bound + * listeners too */ + if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) || + (lookup_type == NFT_LOOKUP_LISTENER && connected)) { + sock_put(sk); + sk = NULL; + } + } + break; + default: + WARN_ON(1); + sk = NULL; + } + + pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n", + protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk); + + return sk; +} + +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) +static inline struct sock * +nf_tproxy_get_sock_v6(struct net *net, const u8 protocol, + const struct in6_addr *saddr, const struct in6_addr *daddr, + const __be16 sport, const __be16 dport, + const struct net_device *in, int lookup_type) +{ + struct sock *sk; + + /* look up socket */ + switch (protocol) { + case IPPROTO_TCP: + switch (lookup_type) { + case NFT_LOOKUP_ANY: + sk = inet6_lookup(net, &tcp_hashinfo, + saddr, sport, daddr, dport, + in->ifindex); + break; + case NFT_LOOKUP_LISTENER: + sk = inet6_lookup_listener(net, &tcp_hashinfo, + daddr, ntohs(dport), + in->ifindex); + + /* NOTE: we return listeners even if bound to + * 0.0.0.0, those are filtered out in + * xt_socket, since xt_TPROXY needs 0 bound + * listeners too */ + + break; + case NFT_LOOKUP_ESTABLISHED: + sk = __inet6_lookup_established(net, &tcp_hashinfo, + saddr, sport, daddr, ntohs(dport), + in->ifindex); + break; + default: + WARN_ON(1); + sk = NULL; + break; + } + break; + case IPPROTO_UDP: + sk = udp6_lib_lookup(net, saddr, sport, daddr, dport, + in->ifindex); + if (sk && lookup_type != NFT_LOOKUP_ANY) { + int connected = (sk->sk_state == TCP_ESTABLISHED); + int wildcard = ipv6_addr_any(&inet6_sk(sk)->rcv_saddr); + + /* NOTE: we return listeners even if bound to + * 0.0.0.0, those are filtered out in + * xt_socket, since xt_TPROXY needs 0 bound + * listeners too */ + if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) || + (lookup_type == NFT_LOOKUP_LISTENER && connected)) { + sock_put(sk); + sk = NULL; + } + } + break; + default: + WARN_ON(1); + sk = NULL; + } + + pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n", + protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk); + + return sk; +} +#endif static inline void nf_tproxy_put_sock(struct sock *sk) diff --git a/include/net/udp.h b/include/net/udp.h index a184d3496b13..200b82848c9a 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -183,6 +183,9 @@ extern int udp_lib_setsockopt(struct sock *sk, int level, int optname, extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, int dif); +extern struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, + const struct in6_addr *daddr, __be16 dport, + int dif); /* * SNMP statistics for UDP and UDP-Lite |