* [PATCH 01/13] Loosen source address check on IPv4 output
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
@ 2007-10-02 20:40 ` KOVACS Krisztian
2007-10-02 20:40 ` [PATCH 02/13] Implement IP_TRANSPARENT socket option KOVACS Krisztian
` (11 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:40 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
ip_route_output() contains a check to make sure that no flows with
non-local source IP addresses are routed. This obviously makes using
such addresses impossible.
This patch introduces a flowi flag which makes omitting this check
possible. The new flag provides a way of handling transparent and
non-transparent connections differently.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Acked-by: Patrick McHardy <kaber@trash.net>
---
include/net/flow.h | 1 +
net/ipv4/route.c | 20 +++++++++++++-------
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/include/net/flow.h b/include/net/flow.h
index af59fa5..c734d50 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -49,6 +49,7 @@ struct flowi {
__u8 proto;
__u8 flags;
#define FLOWI_FLAG_MULTIPATHOLDROUTE 0x01
+#define FLOWI_FLAG_ANYSRC 0x02
union {
struct {
__be16 sport;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c7ca94b..26e9659 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2172,11 +2172,6 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
ZERONET(oldflp->fl4_src))
goto out;
- /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
- dev_out = ip_dev_find(oldflp->fl4_src);
- if (dev_out == NULL)
- goto out;
-
/* I removed check for oif == dev_out->oif here.
It was wrong for two reasons:
1. ip_dev_find(saddr) can return wrong iface, if saddr is
@@ -2187,6 +2182,11 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
if (oldflp->oif == 0
&& (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
+
/* Special hack: user can direct multicasts
and limited broadcast via necessary interface
without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
@@ -2205,9 +2205,15 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
fl.oif = dev_out->ifindex;
goto make_route;
}
- if (dev_out)
+
+ if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
dev_put(dev_out);
- dev_out = NULL;
+ dev_out = NULL;
+ }
}
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 02/13] Implement IP_TRANSPARENT socket option
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
2007-10-02 20:40 ` [PATCH 01/13] Loosen source address check on IPv4 output KOVACS Krisztian
@ 2007-10-02 20:40 ` KOVACS Krisztian
2007-10-02 20:41 ` [PATCH 03/13] Allow binding to non-local addresses if IP_TRANSPARENT is set KOVACS Krisztian
` (10 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:40 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
This patch introduces the IP_TRANSPARENT socket option: enabling that will make
the IPv4 routing omit the non-local source address check on output. Setting
IP_TRANSPARENT requires NET_ADMIN capability.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Acked-by: Patrick McHardy <kaber@trash.net>
---
include/linux/in.h | 1 +
include/net/inet_sock.h | 3 ++-
include/net/inet_timewait_sock.h | 3 ++-
include/net/route.h | 1 +
net/ipv4/inet_timewait_sock.c | 1 +
net/ipv4/ip_sockglue.c | 12 +++++++++++-
6 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/include/linux/in.h b/include/linux/in.h
index 3975cbf..d8c55ab 100644
--- a/include/linux/in.h
+++ b/include/linux/in.h
@@ -75,6 +75,7 @@ struct in_addr {
#define IP_IPSEC_POLICY 16
#define IP_XFRM_POLICY 17
#define IP_PASSSEC 18
+#define IP_TRANSPARENT 19
/* BSD compatibility */
#define IP_RECVRETOPTS IP_RETOPTS
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 62daf21..e86832d 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -128,7 +128,8 @@ struct inet_sock {
is_icsk:1,
freebind:1,
hdrincl:1,
- mc_loop:1;
+ mc_loop:1,
+ transparent:1;
int mc_index;
__be32 mc_addr;
struct ip_mc_socklist *mc_list;
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 47d52b2..23e2fba 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -126,7 +126,8 @@ struct inet_timewait_sock {
__be16 tw_dport;
__u16 tw_num;
/* And these are ours. */
- __u8 tw_ipv6only:1;
+ __u8 tw_ipv6only:1,
+ tw_transparent:1;
/* 15 bits hole, try to pack */
__u16 tw_ipv6_offset;
int tw_timeout;
diff --git a/include/net/route.h b/include/net/route.h
index f7ce625..88fed3c 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -27,6 +27,7 @@
#include <net/dst.h>
#include <net/inetpeer.h>
#include <net/flow.h>
+#include <net/inet_sock.h>
#include <linux/in_route.h>
#include <linux/rtnetlink.h>
#include <linux/route.h>
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 2586df0..cf057a3 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -107,6 +107,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
tw->tw_reuse = sk->sk_reuse;
tw->tw_hash = sk->sk_hash;
tw->tw_ipv6only = 0;
+ tw->tw_transparent = inet->transparent;
tw->tw_prot = sk->sk_prot_creator;
atomic_set(&tw->tw_refcnt, 1);
inet_twsk_dead_node_init(tw);
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 6b420ae..282b187 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -420,7 +420,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
(1<<IP_TTL) | (1<<IP_HDRINCL) |
(1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) |
(1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
- (1<<IP_PASSSEC))) ||
+ (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT))) ||
optname == IP_MULTICAST_TTL ||
optname == IP_MULTICAST_LOOP) {
if (optlen >= sizeof(int)) {
@@ -885,6 +885,16 @@ static int do_ip_setsockopt(struct sock *sk, int level,
err = xfrm_user_policy(sk, optname, optval, optlen);
break;
+ case IP_TRANSPARENT:
+ if (!capable(CAP_NET_ADMIN)) {
+ err = -EPERM;
+ break;
+ }
+ if (optlen < 1)
+ goto e_inval;
+ inet->transparent = !!val;
+ break;
+
default:
err = -ENOPROTOOPT;
break;
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 03/13] Allow binding to non-local addresses if IP_TRANSPARENT is set
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
2007-10-02 20:40 ` [PATCH 01/13] Loosen source address check on IPv4 output KOVACS Krisztian
2007-10-02 20:40 ` [PATCH 02/13] Implement IP_TRANSPARENT socket option KOVACS Krisztian
@ 2007-10-02 20:41 ` KOVACS Krisztian
2007-10-02 20:41 ` [PATCH 04/13] Conditionally enable transparent flow flag when connecting KOVACS Krisztian
` (9 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:41 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Setting IP_TRANSPARENT is not really useful without allowing non-local
binds for the socket. To make user-space code simpler we allow these binds
even if IP_TRANSPARENT is set but IP_FREEBIND is not.
Signed-off-by: Tóth László Attila <panther@balabit.hu>
Acked-by: Patrick McHardy <kaber@trash.net>
---
net/ipv4/af_inet.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index e681034..90344db 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -448,7 +448,7 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
*/
err = -EADDRNOTAVAIL;
if (!sysctl_ip_nonlocal_bind &&
- !inet->freebind &&
+ !(inet->freebind || inet->transparent) &&
addr->sin_addr.s_addr != INADDR_ANY &&
chk_addr_ret != RTN_LOCAL &&
chk_addr_ret != RTN_MULTICAST &&
-
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^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 04/13] Conditionally enable transparent flow flag when connecting
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (2 preceding siblings ...)
2007-10-02 20:41 ` [PATCH 03/13] Allow binding to non-local addresses if IP_TRANSPARENT is set KOVACS Krisztian
@ 2007-10-02 20:41 ` KOVACS Krisztian
2007-10-02 20:42 ` [PATCH 05/13] Handle TCP SYN+ACK/ACK/RST transparency KOVACS Krisztian
` (8 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:41 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Set FLOWI_FLAG_ANYSRC in flowi->flags if the socket has the
transparent socket option set. This way we selectively enable certain
connections with non-local source addresses to be routed.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/net/route.h | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/include/net/route.h b/include/net/route.h
index 88fed3c..9788cc2 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -158,6 +158,10 @@ static inline int ip_route_connect(struct rtable **rp, __be32 dst,
.dport = dport } } };
int err;
+
+ if (inet_sk(sk)->transparent)
+ fl.flags |= FLOWI_FLAG_ANYSRC;
+
if (!dst || !src) {
err = __ip_route_output_key(rp, &fl);
if (err)
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 05/13] Handle TCP SYN+ACK/ACK/RST transparency
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (3 preceding siblings ...)
2007-10-02 20:41 ` [PATCH 04/13] Conditionally enable transparent flow flag when connecting KOVACS Krisztian
@ 2007-10-02 20:42 ` KOVACS Krisztian
2007-10-02 20:42 ` [PATCH 06/13] Port redirection support for TCP KOVACS Krisztian
` (7 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:42 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
The TCP stack sends out SYN+ACK/ACK/RST reply packets in response to
incoming packets. The non-local source address check on output bites
us again, as replies for transparently redirected traffic won't have a
chance to leave the node.
This patch selectively sets the FLOWI_FLAG_ANYSRC flag when doing
the route lookup for those replies. Transparent replies are enabled if
the listening socket has the transparent socket flag set.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/net/inet_sock.h | 8 +++++++-
include/net/ip.h | 9 +++++++++
net/ipv4/inet_connection_sock.c | 1 +
net/ipv4/ip_output.c | 4 +++-
net/ipv4/syncookies.c | 1 +
net/ipv4/tcp_ipv4.c | 11 ++++++++---
6 files changed, 29 insertions(+), 5 deletions(-)
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index e86832d..517efe7 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -72,7 +72,8 @@ struct inet_request_sock {
sack_ok : 1,
wscale_ok : 1,
ecn_ok : 1,
- acked : 1;
+ acked : 1,
+ no_srccheck: 1;
struct ip_options *opt;
};
@@ -191,4 +192,9 @@ static inline int inet_sk_ehashfn(const struct sock *sk)
return inet_ehashfn(laddr, lport, faddr, fport);
}
+static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
+{
+ return inet_sk(sk)->transparent ? FLOWI_FLAG_ANYSRC : 0;
+}
+
#endif /* _INET_SOCK_H */
diff --git a/include/net/ip.h b/include/net/ip.h
index abf2820..fa85f2f 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -29,6 +29,7 @@
#include <net/inet_sock.h>
#include <net/snmp.h>
+#include <net/flow.h>
struct sock;
@@ -140,12 +141,20 @@ static inline void ip_tr_mc_map(__be32 addr, char *buf)
struct ip_reply_arg {
struct kvec iov[1];
+ int flags;
__wsum csum;
int csumoffset; /* u16 offset of csum in iov[0].iov_base */
/* -1 if not needed */
int bound_dev_if;
};
+#define IP_REPLY_ARG_NOSRCCHECK 1
+
+static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
+{
+ return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
+}
+
void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
unsigned int len);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index fbe7714..5c93359 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -321,6 +321,7 @@ struct dst_entry* inet_csk_route_req(struct sock *sk,
.saddr = ireq->loc_addr,
.tos = RT_CONN_FLAGS(sk) } },
.proto = sk->sk_protocol,
+ .flags = inet_sk_flowi_flags(sk),
.uli_u = { .ports =
{ .sport = inet_sk(sk)->sport,
.dport = ireq->rmt_port } } };
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 0f1d7be..9fa376f 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -322,6 +322,7 @@ int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
.saddr = inet->saddr,
.tos = RT_CONN_FLAGS(sk) } },
.proto = sk->sk_protocol,
+ .flags = inet_sk_flowi_flags(sk),
.uli_u = { .ports =
{ .sport = inet->sport,
.dport = inet->dport } } };
@@ -1364,7 +1365,8 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
.uli_u = { .ports =
{ .sport = tcp_hdr(skb)->dest,
.dport = tcp_hdr(skb)->source } },
- .proto = sk->sk_protocol };
+ .proto = sk->sk_protocol,
+ .flags = ip_reply_arg_flowi_flags(arg) };
security_skb_classify_flow(skb, &fl);
if (ip_route_output_key(&rt, &fl))
return;
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 2da1be0..a0f6fdb 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -260,6 +260,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
.saddr = ireq->loc_addr,
.tos = RT_CONN_FLAGS(sk) } },
.proto = IPPROTO_TCP,
+ .flags = inet_sk_flowi_flags(sk),
.uli_u = { .ports =
{ .sport = th->dest,
.dport = th->source } } };
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e089a97..12d3831 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -612,6 +612,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
ip_hdr(skb)->saddr, /* XXX */
sizeof(struct tcphdr), IPPROTO_TCP, 0);
arg.csumoffset = offsetof(struct tcphdr, check) / 2;
+ arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
@@ -625,7 +626,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
struct sk_buff *skb, u32 seq, u32 ack,
- u32 win, u32 ts)
+ u32 win, u32 ts, int reply_flags)
{
struct tcphdr *th = tcp_hdr(skb);
struct {
@@ -701,6 +702,7 @@ static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
arg.iov[0].iov_len);
}
#endif
+ arg.flags = reply_flags;
arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
ip_hdr(skb)->saddr, /* XXX */
arg.iov[0].iov_len, IPPROTO_TCP, 0);
@@ -720,7 +722,8 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
tcp_v4_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
- tcptw->tw_ts_recent);
+ tcptw->tw_ts_recent,
+ tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0);
inet_twsk_put(tw);
}
@@ -730,7 +733,8 @@ static void tcp_v4_reqsk_send_ack(struct sk_buff *skb,
{
tcp_v4_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1,
tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
- req->ts_recent);
+ req->ts_recent,
+ inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0);
}
/*
@@ -1332,6 +1336,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
ireq = inet_rsk(req);
ireq->loc_addr = daddr;
ireq->rmt_addr = saddr;
+ ireq->no_srccheck = inet_sk(sk)->transparent;
ireq->opt = tcp_v4_save_options(sk, skb);
if (!want_cookie)
TCP_ECN_create_request(req, tcp_hdr(skb));
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 06/13] Port redirection support for TCP
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (4 preceding siblings ...)
2007-10-02 20:42 ` [PATCH 05/13] Handle TCP SYN+ACK/ACK/RST transparency KOVACS Krisztian
@ 2007-10-02 20:42 ` KOVACS Krisztian
2007-10-02 20:43 ` [PATCH 07/13] Export UDP socket lookup function KOVACS Krisztian
` (6 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:42 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Current TCP code relies on the local port of the listening socket
being the same as the destination address of the incoming
connection. Port redirection used by many transparent proxying
techniques obviously breaks this, so we have to store the original
destination port address.
This patch extends struct inet_request_sock and stores the incoming
destination port value there. It also modifies the handshake code to
use that value as the source port when sending reply packets.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/net/inet_sock.h | 2 +-
include/net/tcp.h | 1 +
net/ipv4/inet_connection_sock.c | 2 ++
net/ipv4/syncookies.c | 1 +
net/ipv4/tcp_output.c | 2 +-
5 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 517efe7..d7e2a52 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -61,8 +61,8 @@ struct inet_request_sock {
struct request_sock req;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
u16 inet6_rsk_offset;
- /* 2 bytes hole, try to pack */
#endif
+ __be16 loc_port;
__be32 loc_addr;
__be32 rmt_addr;
__be16 rmt_port;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 54053de..6271023 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -980,6 +980,7 @@ static inline void tcp_openreq_init(struct request_sock *req,
ireq->acked = 0;
ireq->ecn_ok = 0;
ireq->rmt_port = tcp_hdr(skb)->source;
+ ireq->loc_port = tcp_hdr(skb)->dest;
}
extern void tcp_enter_memory_pressure(void);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 5c93359..43c37bf 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -501,6 +501,8 @@ struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
newicsk->icsk_bind_hash = NULL;
inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
+ inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
+ inet_sk(newsk)->sport = inet_rsk(req)->loc_port;
newsk->sk_write_space = sk_stream_write_space;
newicsk->icsk_retransmits = 0;
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index a0f6fdb..6e84243 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -223,6 +223,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
treq->rcv_isn = ntohl(th->seq) - 1;
treq->snt_isn = cookie;
req->mss = mss;
+ ireq->loc_port = th->dest;
ireq->rmt_port = th->source;
ireq->loc_addr = ip_hdr(skb)->daddr;
ireq->rmt_addr = ip_hdr(skb)->saddr;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 666d8a5..06f26af 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2153,7 +2153,7 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
th->syn = 1;
th->ack = 1;
TCP_ECN_make_synack(req, th);
- th->source = inet_sk(sk)->sport;
+ th->source = ireq->loc_port;
th->dest = ireq->rmt_port;
TCP_SKB_CB(skb)->seq = tcp_rsk(req)->snt_isn;
TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 07/13] Export UDP socket lookup function
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (5 preceding siblings ...)
2007-10-02 20:42 ` [PATCH 06/13] Port redirection support for TCP KOVACS Krisztian
@ 2007-10-02 20:43 ` KOVACS Krisztian
2007-10-02 20:43 ` [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module KOVACS Krisztian
` (5 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:43 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
The iptables tproxy code has to be able to do UDP socket hash lookups,
so we have to provide an exported lookup function for this purpose.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/net/udp.h | 4 ++++
net/ipv4/udp.c | 8 ++++++++
2 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/include/net/udp.h b/include/net/udp.h
index 98755eb..3efae7d 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -138,6 +138,10 @@ extern int udp_lib_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen,
int (*push_pending_frames)(struct sock *));
+extern struct sock *udp4_lib_lookup(__be32 saddr, __be16 sport,
+ __be32 daddr, __be16 dport,
+ int dif);
+
DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
/*
* SNMP statistics for UDP and UDP-Lite
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 69d4bd1..2fb3b7c 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -287,6 +287,14 @@ static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
return result;
}
+struct sock *udp4_lib_lookup(__be32 saddr, __be16 sport,
+ __be32 daddr, __be16 dport,
+ int dif)
+{
+ return __udp4_lib_lookup(saddr, sport, daddr, dport, dif, udp_hash);
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
__be16 loc_port, __be32 loc_addr,
__be16 rmt_port, __be32 rmt_addr,
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (6 preceding siblings ...)
2007-10-02 20:43 ` [PATCH 07/13] Export UDP socket lookup function KOVACS Krisztian
@ 2007-10-02 20:43 ` KOVACS Krisztian
2007-10-08 8:30 ` Patrick McHardy
2007-10-17 19:11 ` Krzysztof Oledzki
2007-10-02 20:44 ` [PATCH 09/13] iptables tproxy core KOVACS Krisztian
` (4 subsequent siblings)
12 siblings, 2 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:43 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Netfilter connection tracking requires all IPv4 packets to be defragmented.
Both the socket match and the TPROXY target depend on this functionality, so
this patch separates the Netfilter IPv4 defrag hooks into a separate module.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/net/netfilter/ipv4/nf_defrag_ipv4.h | 6 ++
net/ipv4/netfilter/Kconfig | 5 +
net/ipv4/netfilter/Makefile | 3 +
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 55 +-------------
net/ipv4/netfilter/nf_defrag_ipv4.c | 94 ++++++++++++++++++++++++
5 files changed, 110 insertions(+), 53 deletions(-)
diff --git a/include/net/netfilter/ipv4/nf_defrag_ipv4.h b/include/net/netfilter/ipv4/nf_defrag_ipv4.h
new file mode 100644
index 0000000..6b00ea3
--- /dev/null
+++ b/include/net/netfilter/ipv4/nf_defrag_ipv4.h
@@ -0,0 +1,6 @@
+#ifndef _NF_DEFRAG_IPV4_H
+#define _NF_DEFRAG_IPV4_H
+
+extern void nf_defrag_ipv4_enable(void);
+
+#endif /* _NF_DEFRAG_IPV4_H */
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index fa97947..c9108de 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -5,9 +5,14 @@
menu "IP: Netfilter Configuration"
depends on INET && NETFILTER
+config NF_DEFRAG_IPV4
+ tristate
+ default n
+
config NF_CONNTRACK_IPV4
tristate "IPv4 connection tracking support (required for NAT)"
depends on NF_CONNTRACK
+ select NF_DEFRAG_IPV4
---help---
Connection tracking keeps a record of what packets have passed
through your machine, in order to figure out how they are related
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 409d273..6504de5 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -18,6 +18,9 @@ obj-$(CONFIG_NF_CONNTRACK_IPV4) += nf_conntrack_ipv4.o
obj-$(CONFIG_NF_NAT) += nf_nat.o
+# defrag
+obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o
+
# NAT helpers (nf_conntrack)
obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_amanda.o
obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index f813e02..3bc2e0c 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -23,6 +23,7 @@
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
static int ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
struct nf_conntrack_tuple *tuple)
@@ -62,22 +63,6 @@ static int ipv4_print_conntrack(struct seq_file *s,
return 0;
}
-/* Returns new sk_buff, or NULL */
-static struct sk_buff *
-nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
-{
- skb_orphan(skb);
-
- local_bh_disable();
- skb = ip_defrag(skb, user);
- local_bh_enable();
-
- if (skb)
- ip_send_check(ip_hdr(skb));
-
- return skb;
-}
-
static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
unsigned int *dataoff, u_int8_t *protonum)
{
@@ -135,29 +120,6 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum,
ct, ctinfo);
}
-static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
- struct sk_buff **pskb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
-{
- /* Previously seen (loopback)? Ignore. Do this before
- fragment check. */
- if ((*pskb)->nfct)
- return NF_ACCEPT;
-
- /* Gather fragments. */
- if (ip_hdr(*pskb)->frag_off & htons(IP_MF | IP_OFFSET)) {
- *pskb = nf_ct_ipv4_gather_frags(*pskb,
- hooknum == NF_IP_PRE_ROUTING ?
- IP_DEFRAG_CONNTRACK_IN :
- IP_DEFRAG_CONNTRACK_OUT);
- if (!*pskb)
- return NF_STOLEN;
- }
- return NF_ACCEPT;
-}
-
static unsigned int ipv4_conntrack_in(unsigned int hooknum,
struct sk_buff **pskb,
const struct net_device *in,
@@ -187,13 +149,6 @@ static unsigned int ipv4_conntrack_local(unsigned int hooknum,
make it the first hook. */
static struct nf_hook_ops ipv4_conntrack_ops[] = {
{
- .hook = ipv4_conntrack_defrag,
- .owner = THIS_MODULE,
- .pf = PF_INET,
- .hooknum = NF_IP_PRE_ROUTING,
- .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
- },
- {
.hook = ipv4_conntrack_in,
.owner = THIS_MODULE,
.pf = PF_INET,
@@ -201,13 +156,6 @@ static struct nf_hook_ops ipv4_conntrack_ops[] = {
.priority = NF_IP_PRI_CONNTRACK,
},
{
- .hook = ipv4_conntrack_defrag,
- .owner = THIS_MODULE,
- .pf = PF_INET,
- .hooknum = NF_IP_LOCAL_OUT,
- .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
- },
- {
.hook = ipv4_conntrack_local,
.owner = THIS_MODULE,
.pf = PF_INET,
@@ -430,6 +378,7 @@ static int __init nf_conntrack_l3proto_ipv4_init(void)
int ret = 0;
need_conntrack();
+ nf_defrag_ipv4_enable();
ret = nf_register_sockopt(&so_getorigdst);
if (ret < 0) {
diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c
new file mode 100644
index 0000000..9872c47
--- /dev/null
+++ b/net/ipv4/netfilter/nf_defrag_ipv4.c
@@ -0,0 +1,94 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <net/ip.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+
+/* Returns new sk_buff, or NULL */
+static struct sk_buff *
+ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
+{
+ skb_orphan(skb);
+
+ local_bh_disable();
+ skb = ip_defrag(skb, user);
+ local_bh_enable();
+
+ if (skb)
+ ip_send_check(ip_hdr(skb));
+
+ return skb;
+}
+
+static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ /* Previously seen (loopback)? Ignore. Do this before
+ fragment check. */
+ if ((*pskb)->nfct)
+ return NF_ACCEPT;
+
+ /* Gather fragments. */
+ if (ip_hdr(*pskb)->frag_off & htons(IP_MF | IP_OFFSET)) {
+ *pskb = ipv4_gather_frags(*pskb,
+ hooknum == NF_IP_PRE_ROUTING ?
+ IP_DEFRAG_CONNTRACK_IN :
+ IP_DEFRAG_CONNTRACK_OUT);
+ if (!*pskb)
+ return NF_STOLEN;
+ }
+ return NF_ACCEPT;
+}
+
+static struct nf_hook_ops ipv4_defrag_ops[] = {
+ {
+ .hook = ipv4_conntrack_defrag,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_PRE_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
+ },
+ {
+ .hook = ipv4_conntrack_defrag,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_OUT,
+ .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
+ },
+};
+
+static int __init nf_defrag_init(void)
+{
+ return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
+}
+
+static void __exit nf_defrag_fini(void)
+{
+ nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
+}
+
+void nf_defrag_ipv4_enable(void)
+{
+}
+EXPORT_SYMBOL(nf_defrag_ipv4_enable);
+
+module_init(nf_defrag_init);
+module_exit(nf_defrag_fini);
+
+MODULE_LICENSE("GPL");
^ permalink raw reply related [flat|nested] 19+ messages in thread* Re: [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module
2007-10-02 20:43 ` [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module KOVACS Krisztian
@ 2007-10-08 8:30 ` Patrick McHardy
2007-10-17 19:11 ` Krzysztof Oledzki
1 sibling, 0 replies; 19+ messages in thread
From: Patrick McHardy @ 2007-10-08 8:30 UTC (permalink / raw)
To: KOVACS Krisztian; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
KOVACS Krisztian wrote:
> +void nf_defrag_ipv4_enable(void)
> +{
> +}
> +EXPORT_SYMBOL(nf_defrag_ipv4_enable);
A bit pointless for this function, but I'd prefer
EXPORT_SYMBOL_GPL for consistenty :)
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module
2007-10-02 20:43 ` [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module KOVACS Krisztian
2007-10-08 8:30 ` Patrick McHardy
@ 2007-10-17 19:11 ` Krzysztof Oledzki
2007-10-23 18:26 ` KOVACS Krisztian
1 sibling, 1 reply; 19+ messages in thread
From: Krzysztof Oledzki @ 2007-10-17 19:11 UTC (permalink / raw)
To: KOVACS Krisztian
Cc: Patrick McHardy, netfilter-devel, Balazs Scheidler,
Toth Laszlo Attila
[-- Attachment #1: Type: TEXT/PLAIN, Size: 1087 bytes --]
Hello,
On Tue, 2 Oct 2007, KOVACS Krisztian wrote:
> Netfilter connection tracking requires all IPv4 packets to be defragmented.
> Both the socket match and the TPROXY target depend on this functionality, so
> this patch separates the Netfilter IPv4 defrag hooks into a separate module.
With this patch taken from:
http://people.netfilter.org/hidden/tproxy/tproxy4-2.6.23-200710090922.tar.bz2
with:
# CONFIG_NF_CONNTRACK_ENABLED is not set
# CONFIG_NF_CONNTRACK is not set
I get:
net/ipv4/netfilter/nf_defrag_ipv4.c: In function 'ipv4_conntrack_defrag':
net/ipv4/netfilter/nf_defrag_ipv4.c:44: error: 'struct sk_buff' has no member named 'nfct'
make[3]: *** [net/ipv4/netfilter/nf_defrag_ipv4.o] Error 1
make[2]: *** [net/ipv4/netfilter] Error 2
make[1]: *** [net/ipv4] Error 2
This is not a surprise since:
--- cut here ---
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct nf_conntrack *nfct;
struct sk_buff *nfct_reasm;
#endif
--- cut here ---
Best regards,
Krzysztof Olędzki
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module
2007-10-17 19:11 ` Krzysztof Oledzki
@ 2007-10-23 18:26 ` KOVACS Krisztian
0 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-23 18:26 UTC (permalink / raw)
To: Krzysztof Oledzki
Cc: Patrick McHardy, netfilter-devel, Balazs Scheidler,
Toth Laszlo Attila
Hi Krzysztof,
On Wednesday 17 October 2007, Krzysztof Oledzki wrote:
> On Tue, 2 Oct 2007, KOVACS Krisztian wrote:
> > Netfilter connection tracking requires all IPv4 packets to be
> > defragmented. Both the socket match and the TPROXY target depend on
> > this functionality, so this patch separates the Netfilter IPv4 defrag
> > hooks into a separate module.
>
> With this patch taken from:
>
> http://people.netfilter.org/hidden/tproxy/tproxy4-2.6.23-200710090922.t
>ar.bz2 with:
> # CONFIG_NF_CONNTRACK_ENABLED is not set
> # CONFIG_NF_CONNTRACK is not set
>
> I get:
>
> net/ipv4/netfilter/nf_defrag_ipv4.c: In function
> 'ipv4_conntrack_defrag': net/ipv4/netfilter/nf_defrag_ipv4.c:44: error:
> 'struct sk_buff' has no member named 'nfct' make[3]: ***
> [net/ipv4/netfilter/nf_defrag_ipv4.o] Error 1
> make[2]: *** [net/ipv4/netfilter] Error 2
> make[1]: *** [net/ipv4] Error 2
>
> This is not a surprise since:
> --- cut here ---
> #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
> struct nf_conntrack *nfct;
> struct sk_buff *nfct_reasm;
> #endif
> --- cut here ---
Thanks for spotting this, indeed, this was an oversight from my part...
The latest tree at http://people.netfilter.org/hidden/tproxy/ should fix
this compilation problem.
--
KOVACS Krisztian
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 09/13] iptables tproxy core
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (7 preceding siblings ...)
2007-10-02 20:43 ` [PATCH 08/13] Split Netfilter IPv4 defragmentation into a separate module KOVACS Krisztian
@ 2007-10-02 20:44 ` KOVACS Krisztian
2007-10-02 20:44 ` [PATCH 10/13] iptables socket match KOVACS Krisztian
` (3 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:44 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
The iptables tproxy core is a module that contains the common routines used by
various tproxy related modules (TPROXY target and socket match)
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/net/netfilter/nf_tproxy_core.h | 32 +++++++++++
net/netfilter/Kconfig | 10 +++
net/netfilter/Makefile | 3 +
net/netfilter/nf_tproxy_core.c | 96 ++++++++++++++++++++++++++++++++
4 files changed, 141 insertions(+), 0 deletions(-)
diff --git a/include/net/netfilter/nf_tproxy_core.h b/include/net/netfilter/nf_tproxy_core.h
new file mode 100644
index 0000000..2fac3ad
--- /dev/null
+++ b/include/net/netfilter/nf_tproxy_core.h
@@ -0,0 +1,32 @@
+#ifndef _NF_TPROXY_CORE_H
+#define _NF_TPROXY_CORE_H
+
+#include <linux/types.h>
+#include <linux/in.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/inet_sock.h>
+#include <net/tcp.h>
+
+/* look up and get a reference to a matching socket */
+extern struct sock *
+nf_tproxy_get_sock_v4(const u8 protocol,
+ const __be32 saddr, const __be32 daddr,
+ const __be16 sport, const __be16 dport,
+ const struct net_device *in, bool listening);
+
+static inline void
+nf_tproxy_put_sock(struct sock *sk)
+{
+ /* TIME_WAIT inet sockets have to be handled differently */
+ if ((sk->sk_protocol == IPPROTO_TCP) && (sk->sk_state == TCP_TIME_WAIT))
+ inet_twsk_put(inet_twsk(sk));
+ else
+ sock_put(sk);
+}
+
+/* assign a socket to the skb -- consumes sk */
+int
+nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk);
+
+#endif
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 3599770..2187cca 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -257,6 +257,16 @@ config NF_CT_NETLINK
help
This option enables support for a netlink-based userspace interface
+# transparent proxy support
+config NETFILTER_TPROXY
+ tristate "Transparent proxying support"
+ depends on IP_NF_MANGLE
+ help
+ Transparent proxying. For more information see
+ http://www.balabit.com/downloads/tproxy.
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config NETFILTER_XTABLES
tristate "Netfilter Xtables support (required for ip_tables)"
help
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 0c054bf..76e16ea 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -34,6 +34,9 @@ obj-$(CONFIG_NF_CONNTRACK_SANE) += nf_conntrack_sane.o
obj-$(CONFIG_NF_CONNTRACK_SIP) += nf_conntrack_sip.o
obj-$(CONFIG_NF_CONNTRACK_TFTP) += nf_conntrack_tftp.o
+# transparent proxy support
+obj-$(CONFIG_NETFILTER_TPROXY) += nf_tproxy_core.o
+
# generic X tables
obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
diff --git a/net/netfilter/nf_tproxy_core.c b/net/netfilter/nf_tproxy_core.c
new file mode 100644
index 0000000..f842c02
--- /dev/null
+++ b/net/netfilter/nf_tproxy_core.c
@@ -0,0 +1,96 @@
+/*
+ * Transparent proxy support for Linux/iptables
+ *
+ * Copyright (c) 2006-2007 BalaBit IT Ltd.
+ * Author: Balazs Scheidler, Krisztian Kovacs
+ *
+ * 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/version.h>
+#include <linux/module.h>
+
+#include <linux/net.h>
+#include <linux/if.h>
+#include <linux/netdevice.h>
+#include <net/udp.h>
+#include <net/netfilter/nf_tproxy_core.h>
+
+struct sock *
+nf_tproxy_get_sock_v4(const u8 protocol,
+ const __be32 saddr, const __be32 daddr,
+ const __be16 sport, const __be16 dport,
+ const struct net_device *in, bool listening_only)
+{
+ struct sock *sk;
+
+ /* look up socket */
+ switch (protocol) {
+ case IPPROTO_TCP:
+ if (listening_only)
+ sk = __inet_lookup_listener(&tcp_hashinfo,
+ daddr, ntohs(dport),
+ in->ifindex);
+ else
+ sk = __inet_lookup(&tcp_hashinfo,
+ saddr, sport, daddr, dport,
+ in->ifindex);
+ break;
+ case IPPROTO_UDP:
+ sk = udp4_lib_lookup(saddr, sport, daddr, dport,
+ in->ifindex);
+ break;
+ default:
+ WARN_ON(1);
+ sk = NULL;
+ }
+
+ pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u sock %p\n",
+ protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), sk);
+
+ return sk;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v4);
+
+static void
+nf_tproxy_destructor(struct sk_buff *skb)
+{
+ struct sock *sk = skb->sk;
+
+ skb->sk = NULL;
+ skb->destructor = NULL;
+
+ if (sk)
+ nf_tproxy_put_sock(sk);
+}
+
+/* consumes sk */
+int
+nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
+{
+ if (inet_sk(sk)->transparent) {
+ skb->sk = sk;
+ skb->destructor = nf_tproxy_destructor;
+ return 1;
+ } else
+ nf_tproxy_put_sock(sk);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_assign_sock);
+
+static int __init init(void)
+{
+ printk("NF_TPROXY: Transparent proxy support initialized, version 4.1.0\n"
+ "NF_TPROXY: Copyright (c) 2006-2007 BalaBit IT Ltd.\n");
+ return 0;
+}
+
+module_init(init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Krisztian Kovacs");
+MODULE_DESCRIPTION("Transparent proxy core routines");
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 10/13] iptables socket match
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (8 preceding siblings ...)
2007-10-02 20:44 ` [PATCH 09/13] iptables tproxy core KOVACS Krisztian
@ 2007-10-02 20:44 ` KOVACS Krisztian
2007-10-08 8:32 ` Patrick McHardy
2007-10-02 20:45 ` [PATCH 11/13] iptables TPROXY target KOVACS Krisztian
` (2 subsequent siblings)
12 siblings, 1 reply; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:44 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Add iptables 'socket' match, which matches packets for which a TCP/UDP
socket lookup succeeds.
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
net/netfilter/Kconfig | 12 +++++++
net/netfilter/Makefile | 1 +
net/netfilter/xt_socket.c | 83 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 96 insertions(+), 0 deletions(-)
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 2187cca..899fdde 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -632,6 +632,18 @@ config NETFILTER_XT_MATCH_SCTP
If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>. If unsure, say `N'.
+config NETFILTER_XT_MATCH_SOCKET
+ tristate '"socket" match support'
+ depends on NETFILTER_TPROXY
+ depends on NETFILTER_XTABLES
+ select NF_DEFRAG_IPV4
+ help
+ This option adds a `socket' match, which can be used to match
+ packets for which a TCP or UDP socket lookup finds a valid socket.
+ It can only be used in the tproxy table.
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config NETFILTER_XT_MATCH_STATE
tristate '"state" match support'
depends on NETFILTER_XTABLES
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 76e16ea..7d7dbd6 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -73,6 +73,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_PKTTYPE) += xt_pkttype.o
obj-$(CONFIG_NETFILTER_XT_MATCH_QUOTA) += xt_quota.o
obj-$(CONFIG_NETFILTER_XT_MATCH_REALM) += xt_realm.o
obj-$(CONFIG_NETFILTER_XT_MATCH_SCTP) += xt_sctp.o
+obj-$(CONFIG_NETFILTER_XT_MATCH_SOCKET) += xt_socket.o
obj-$(CONFIG_NETFILTER_XT_MATCH_STATE) += xt_state.o
obj-$(CONFIG_NETFILTER_XT_MATCH_STATISTIC) += xt_statistic.o
obj-$(CONFIG_NETFILTER_XT_MATCH_STRING) += xt_string.o
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
new file mode 100644
index 0000000..285dfa8
--- /dev/null
+++ b/net/netfilter/xt_socket.c
@@ -0,0 +1,83 @@
+/*
+ * Transparent proxy support for Linux/iptables
+ *
+ * Copyright (C) 2007 BalaBit IT Ltd.
+ * Author: Krisztian Kovacs
+ *
+ * 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/skbuff.h>
+#include <linux/netfilter/x_tables.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/sock.h>
+#include <net/inet_sock.h>
+#include <net/netfilter/nf_tproxy_core.h>
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+
+static bool
+socket_match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct xt_match *match,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ bool *hotdrop)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+ struct udphdr _hdr, *hp;
+ struct sock *sk;
+
+ /* TCP/UDP only */
+ if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)
+ return false;
+
+ hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
+ if (hp == NULL)
+ return false;
+
+ sk = nf_tproxy_get_sock_v4(iph->protocol,
+ iph->saddr, iph->daddr,
+ hp->source, hp->dest, in, false);
+ if (sk != NULL)
+ nf_tproxy_put_sock(sk);
+
+ pr_debug("socket match: proto %u %08x:%u -> %08x:%u sock %p\n",
+ iph->protocol, ntohl(iph->saddr), ntohs(hp->source),
+ ntohl(iph->daddr), ntohs(hp->dest), sk);
+
+ return (sk != NULL);
+}
+
+static struct xt_match xt_socket_reg __read_mostly = {
+ .name = "socket",
+ .family = AF_INET,
+ .match = socket_match,
+ .hooks = (1 << NF_IP_PRE_ROUTING),
+ .me = THIS_MODULE,
+};
+
+static int __init xt_socket_init(void)
+{
+ nf_defrag_ipv4_enable();
+ return xt_register_match(&xt_socket_reg);
+}
+
+static void __exit xt_socket_fini(void)
+{
+ xt_unregister_match(&xt_socket_reg);
+}
+
+module_init(xt_socket_init);
+module_exit(xt_socket_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Krisztian Kovacs");
+MODULE_DESCRIPTION("x_tables socket match module");
+MODULE_ALIAS("ipt_socket");
^ permalink raw reply related [flat|nested] 19+ messages in thread* Re: [PATCH 10/13] iptables socket match
2007-10-02 20:44 ` [PATCH 10/13] iptables socket match KOVACS Krisztian
@ 2007-10-08 8:32 ` Patrick McHardy
0 siblings, 0 replies; 19+ messages in thread
From: Patrick McHardy @ 2007-10-08 8:32 UTC (permalink / raw)
To: KOVACS Krisztian; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
KOVACS Krisztian wrote:
> +config NETFILTER_XT_MATCH_SOCKET
> + tristate '"socket" match support'
> + depends on NETFILTER_TPROXY
> + depends on NETFILTER_XTABLES
EXPERIMENTAL please.
> +static bool
> +socket_match(const struct sk_buff *skb,
> + const struct net_device *in,
> + const struct net_device *out,
> + const struct xt_match *match,
> + const void *matchinfo,
> + int offset,
> + unsigned int protoff,
> + bool *hotdrop)
> +{
> + const struct iphdr *iph = ip_hdr(skb);
> + struct udphdr _hdr, *hp;
> + struct sock *sk;
> +
> + /* TCP/UDP only */
> + if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)
> + return false;
How about making sure that its only used in a -p udp or -p tcp
rule in ->checkentry() instead?
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 11/13] iptables TPROXY target
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (9 preceding siblings ...)
2007-10-02 20:44 ` [PATCH 10/13] iptables socket match KOVACS Krisztian
@ 2007-10-02 20:45 ` KOVACS Krisztian
2007-10-08 8:34 ` Patrick McHardy
2007-10-02 20:45 ` [PATCH 12/13] Don't lookup the socket if there's a socket attached to the skb KOVACS Krisztian
2007-10-02 20:46 ` [PATCH 13/13] " KOVACS Krisztian
12 siblings, 1 reply; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:45 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
The TPROXY target implements redirection of non-local TCP/UDP traffic to local
sockets. Additionally, it's possible to manipulate the packet mark if and only
if a socket has been found. (We need this because we cannot use multiple
targets in the same iptables rule.)
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
include/linux/netfilter/xt_TPROXY.h | 14 +++++
net/netfilter/Kconfig | 13 +++++
net/netfilter/Makefile | 1
net/netfilter/xt_TPROXY.c | 97 +++++++++++++++++++++++++++++++++++
4 files changed, 125 insertions(+), 0 deletions(-)
diff --git a/include/linux/netfilter/xt_TPROXY.h b/include/linux/netfilter/xt_TPROXY.h
new file mode 100644
index 0000000..152e8f9
--- /dev/null
+++ b/include/linux/netfilter/xt_TPROXY.h
@@ -0,0 +1,14 @@
+#ifndef _XT_TPROXY_H_target
+#define _XT_TPROXY_H_target
+
+/* TPROXY target is capable of marking the packet to perform
+ * redirection. We can get rid of that whenever we get support for
+ * mutliple targets in the same rule. */
+struct xt_tproxy_target_info {
+ u_int32_t mark_mask;
+ u_int32_t mark_value;
+ __be32 laddr;
+ __be16 lport;
+};
+
+#endif /* _XT_TPROXY_H_target */
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 899fdde..441e46f 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -363,6 +363,19 @@ config NETFILTER_XT_TARGET_NOTRACK
If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>. If unsure, say `N'.
+config NETFILTER_XT_TARGET_TPROXY
+ tristate '"TPROXY" target support'
+ depends on NETFILTER_TPROXY
+ depends on NETFILTER_XTABLES
+ select NF_DEFRAG_IPV4
+ help
+ This option adds a `TPROXY' target, which is somewhat similar to
+ REDIRECT. It can only be used in the mangle table and is useful
+ to redirect traffic to a transparent proxy. It does _not_ depend
+ on Netfilter connection tracking and NAT, unlike REDIRECT.
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config NETFILTER_XT_TARGET_TRACE
tristate '"TRACE" target support'
depends on NETFILTER_XTABLES
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 7d7dbd6..0684e2b 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_TPROXY) += xt_TPROXY.o
obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
new file mode 100644
index 0000000..395dad3
--- /dev/null
+++ b/net/netfilter/xt_TPROXY.c
@@ -0,0 +1,97 @@
+/*
+ * Transparent proxy support for Linux/iptables
+ *
+ * Copyright (c) 2006-2007 BalaBit IT Ltd.
+ * Author: Balazs Scheidler, Krisztian Kovacs
+ *
+ * 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/skbuff.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/inet_sock.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_TPROXY.h>
+
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+#include <net/netfilter/nf_tproxy_core.h>
+
+static unsigned int
+tproxy_target(struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const struct xt_target *target,
+ const void *targinfo)
+{
+ const struct iphdr *iph = ip_hdr(*pskb);
+ const struct xt_tproxy_target_info *tgi = targinfo;
+ struct sk_buff *skb = *pskb;
+ struct udphdr _hdr, *hp;
+ struct sock *sk;
+
+ /* TCP/UDP only */
+ if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)
+ return NF_ACCEPT;
+
+ hp = skb_header_pointer(*pskb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
+ if (hp == NULL)
+ return NF_DROP;
+
+ sk = nf_tproxy_get_sock_v4(iph->protocol,
+ iph->saddr, tgi->laddr ? tgi->laddr : iph->daddr,
+ hp->source, tgi->lport ? tgi->lport : hp->dest,
+ in, true);
+
+ /* NOTE: assign_sock consumes our sk reference */
+ if (sk && nf_tproxy_assign_sock(skb, sk)) {
+ /* This should be in a separate target, but we don't do multiple
+ targets on the same rule yet */
+ skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
+
+ pr_debug("redirecting: proto %u %08x:%u -> %08x:%u, mark: %x\n",
+ iph->protocol, ntohl(iph->daddr), ntohs(hp->dest),
+ ntohl(tgi->laddr), ntohs(tgi->lport), skb->mark);
+ return NF_ACCEPT;
+ }
+
+ pr_debug("no socket, dropping: proto %u %08x:%u -> %08x:%u, mark: %x\n",
+ iph->protocol, ntohl(iph->daddr), ntohs(hp->dest),
+ ntohl(tgi->laddr), ntohs(tgi->lport), skb->mark);
+ return NF_DROP;
+}
+
+static struct xt_target xt_tproxy_reg __read_mostly = {
+ .name = "TPROXY",
+ .family = AF_INET,
+ .table = "mangle",
+ .target = tproxy_target,
+ .targetsize = sizeof(struct xt_tproxy_target_info),
+ .hooks = 1 << NF_IP_PRE_ROUTING,
+ .me = THIS_MODULE,
+};
+
+static int __init xt_tproxy_init(void)
+{
+ nf_defrag_ipv4_enable();
+ return xt_register_target(&xt_tproxy_reg);
+}
+
+static void __exit xt_tproxy_fini(void)
+{
+ xt_unregister_target(&xt_tproxy_reg);
+}
+
+module_init(xt_tproxy_init);
+module_exit(xt_tproxy_fini);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Krisztian Kovacs");
+MODULE_DESCRIPTION("Netfilter transparent proxy (TPROXY) target module.");
+MODULE_ALIAS("ipt_TPROXY");
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 12/13] Don't lookup the socket if there's a socket attached to the skb
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (10 preceding siblings ...)
2007-10-02 20:45 ` [PATCH 11/13] iptables TPROXY target KOVACS Krisztian
@ 2007-10-02 20:45 ` KOVACS Krisztian
2007-10-02 20:46 ` [PATCH 13/13] " KOVACS Krisztian
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:45 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Use the socket cached in the TPROXY target if it's present.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
net/ipv4/tcp_ipv4.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 12d3831..f3e3c5e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1661,6 +1661,14 @@ int tcp_v4_rcv(struct sk_buff *skb)
TCP_SKB_CB(skb)->flags = iph->tos;
TCP_SKB_CB(skb)->sacked = 0;
+#if defined(CONFIG_NETFILTER_TPROXY) || defined (CONFIG_NETFILTER_TPROXY_MODULE)
+ if (unlikely(skb->sk)) {
+ /* steal reference */
+ sk = skb->sk;
+ skb->destructor = NULL;
+ skb->sk = NULL;
+ } else
+#endif
sk = __inet_lookup(&tcp_hashinfo, iph->saddr, th->source,
iph->daddr, th->dest, inet_iif(skb));
if (!sk)
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 13/13] Don't lookup the socket if there's a socket attached to the skb
2007-10-02 20:39 [PATCH 00/13] Transparent Proxying Patches, Take 4 KOVACS Krisztian
` (11 preceding siblings ...)
2007-10-02 20:45 ` [PATCH 12/13] Don't lookup the socket if there's a socket attached to the skb KOVACS Krisztian
@ 2007-10-02 20:46 ` KOVACS Krisztian
12 siblings, 0 replies; 19+ messages in thread
From: KOVACS Krisztian @ 2007-10-02 20:46 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, Balazs Scheidler, Toth Laszlo Attila
Use the socket cached in the TPROXY target if it's present.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
---
net/ipv4/udp.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 2fb3b7c..d1fefb6 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1151,6 +1151,14 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
+#if defined(CONFIG_NETFILTER_TPROXY) || defined (CONFIG_NETFILTER_TPROXY_MODULE)
+ if (unlikely(skb->sk)) {
+ /* steal reference */
+ sk = skb->sk;
+ skb->destructor = NULL;
+ skb->sk = NULL;
+ } else
+#endif
sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
skb->dev->ifindex, udptable );
^ permalink raw reply related [flat|nested] 19+ messages in thread