From: "Jason A. Donenfeld" <Jason@zx2c4•com>
To: netdev@vger•kernel.org, davem@davemloft•net
Cc: "Jason A. Donenfeld" <Jason@zx2c4•com>, Florian Westphal <fw@strlen•de>
Subject: [PATCH v3 net 1/9] icmp: introduce helper for nat'd source address in network device context
Date: Tue, 11 Feb 2020 16:00:20 +0100 [thread overview]
Message-ID: <20200211150028.688073-2-Jason@zx2c4.com> (raw)
In-Reply-To: <20200211150028.688073-1-Jason@zx2c4.com>
This introduces a helper function to be called only by network drivers
that wraps calls to icmp[v6]_send in a conntrack transformation, in case
NAT has been used. The transformation happens only from a non-shared skb
context, and the skb is fixed back up to its original state after, in
case the calling code continues to use it.
We don't want to pollute the non-driver path, though, so we introduce
this as a helper to be called by places that actually make use of
this, as suggested by Florian.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4•com>
Cc: Florian Westphal <fw@strlen•de>
---
include/linux/icmpv6.h | 6 ++++++
include/net/icmp.h | 6 ++++++
net/ipv4/icmp.c | 28 ++++++++++++++++++++++++++++
net/ipv6/ip6_icmp.c | 29 +++++++++++++++++++++++++++++
4 files changed, 69 insertions(+)
diff --git a/include/linux/icmpv6.h b/include/linux/icmpv6.h
index ef1cbb5f454f..93338fd54af8 100644
--- a/include/linux/icmpv6.h
+++ b/include/linux/icmpv6.h
@@ -31,6 +31,12 @@ static inline void icmpv6_send(struct sk_buff *skb,
}
#endif
+#if IS_ENABLED(CONFIG_NF_NAT)
+void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info);
+#else
+#define icmpv6_ndo_send icmpv6_send
+#endif
+
extern int icmpv6_init(void);
extern int icmpv6_err_convert(u8 type, u8 code,
int *err);
diff --git a/include/net/icmp.h b/include/net/icmp.h
index 5d4bfdba9adf..9ac2d2672a93 100644
--- a/include/net/icmp.h
+++ b/include/net/icmp.h
@@ -43,6 +43,12 @@ static inline void icmp_send(struct sk_buff *skb_in, int type, int code, __be32
__icmp_send(skb_in, type, code, info, &IPCB(skb_in)->opt);
}
+#if IS_ENABLED(CONFIG_NF_NAT)
+void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info);
+#else
+#define icmp_ndo_send icmp_send
+#endif
+
int icmp_rcv(struct sk_buff *skb);
int icmp_err(struct sk_buff *skb, u32 info);
int icmp_init(void);
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 18068ed42f25..0cd23df4ad5c 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -748,6 +748,34 @@ out:;
}
EXPORT_SYMBOL(__icmp_send);
+#if IS_ENABLED(CONFIG_NF_NAT)
+#include <net/netfilter/nf_conntrack.h>
+void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info)
+{
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+ __be32 orig_ip;
+
+ ct = nf_ct_get(skb_in, &ctinfo);
+ if (!ct || !(ct->status & IPS_SRC_NAT)) {
+ icmp_send(skb_in, type, code, info);
+ return;
+ }
+
+ if (unlikely(WARN_ON(skb_shared(skb_in)) ||
+ skb_network_header(skb_in) < skb_in->head ||
+ (skb_network_header(skb_in) + sizeof(struct iphdr)) >
+ skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in,
+ skb_network_offset(skb_in) + sizeof(struct iphdr))))
+ return;
+
+ orig_ip = ip_hdr(skb_in)->saddr;
+ ip_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.ip;
+ icmp_send(skb_in, type, code, info);
+ ip_hdr(skb_in)->saddr = orig_ip;
+}
+EXPORT_SYMBOL(icmp_ndo_send);
+#endif
static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
{
diff --git a/net/ipv6/ip6_icmp.c b/net/ipv6/ip6_icmp.c
index 02045494c24c..00e94e1dffae 100644
--- a/net/ipv6/ip6_icmp.c
+++ b/net/ipv6/ip6_icmp.c
@@ -45,4 +45,33 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
rcu_read_unlock();
}
EXPORT_SYMBOL(icmpv6_send);
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+#include <net/netfilter/nf_conntrack.h>
+void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info)
+{
+ enum ip_conntrack_info ctinfo;
+ struct in6_addr orig_ip;
+ struct nf_conn *ct;
+
+ ct = nf_ct_get(skb_in, &ctinfo);
+ if (!ct || !(ct->status & IPS_SRC_NAT)) {
+ icmpv6_send(skb_in, type, code, info);
+ return;
+ }
+
+ if (unlikely(WARN_ON(skb_shared(skb_in)) ||
+ skb_network_header(skb_in) < skb_in->head ||
+ (skb_network_header(skb_in) + sizeof(struct ipv6hdr)) >
+ skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in,
+ skb_network_offset(skb_in) + sizeof(struct ipv6hdr))))
+ return;
+
+ orig_ip = ipv6_hdr(skb_in)->saddr;
+ ipv6_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.in6;
+ icmpv6_send(skb_in, type, code, info);
+ ipv6_hdr(skb_in)->saddr = orig_ip;
+}
+EXPORT_SYMBOL(icmpv6_ndo_send);
+#endif
#endif
--
2.25.0
next prev parent reply other threads:[~2020-02-11 15:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-10 14:14 [PATCH v2 net 0/5] icmp: account for NAT when sending icmps from ndo layer Jason A. Donenfeld
2020-02-10 14:14 ` [PATCH v2 net 1/5] icmp: introduce helper for NAT'd source address in network device context Jason A. Donenfeld
2020-02-10 19:48 ` Jason A. Donenfeld
2020-02-10 21:32 ` Florian Westphal
2020-02-10 21:59 ` Jason A. Donenfeld
2020-02-10 22:26 ` Florian Westphal
2020-02-11 9:59 ` Jason A. Donenfeld
2020-02-11 12:25 ` Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 0/9] icmp: account for NAT when sending icmps from ndo layer Jason A. Donenfeld
2020-02-11 15:00 ` Jason A. Donenfeld [this message]
2020-02-11 15:00 ` [PATCH v3 net 2/9] gtp: use icmp_ndo_send helper Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 3/9] sunvnet: " Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 4/9] xfrm: interface: " Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 5/9] wireguard: device: use icmp_ndo_send helper and remove skb_share_check Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 6/9] firewire: remove skb_share_check from xmit path Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 7/9] ipvlan: " Jason A. Donenfeld
2020-02-11 17:39 ` Eric Dumazet
2020-02-11 17:44 ` Jason A. Donenfeld
2020-02-11 18:50 ` Eric Dumazet
2020-02-11 18:54 ` Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 8/9] fm10k: " Jason A. Donenfeld
2020-02-11 15:00 ` [PATCH v3 net 9/9] benet: " Jason A. Donenfeld
2020-02-10 14:14 ` [PATCH v2 net 2/5] gtp: use icmp_ndo_send helper Jason A. Donenfeld
2020-02-10 14:14 ` [PATCH v2 net 3/5] sunvnet: " Jason A. Donenfeld
2020-02-10 14:14 ` [PATCH v2 net 4/5] wireguard: " Jason A. Donenfeld
2020-02-10 14:14 ` [PATCH v2 net 5/5] xfrm: interface: " Jason A. Donenfeld
2020-02-10 19:30 ` [PATCH v2 net 6/5] wireguard: selftests: ensure that icmp src address is correct with NAT Jason A. Donenfeld
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