From 6f489c42a92e0e33d4257017d6fd4a3e79f75f79 Mon Sep 17 00:00:00 2001 From: JP Abgrall Date: Thu, 16 Jun 2011 14:37:03 -0700 Subject: [PATCH] netfilter: have ip*t REJECT set the sock err when an icmp is to be sent Allow the REJECT --reject-with icmp*blabla to also set the matching error locally on the socket affected by the reject. This allows the process to see an error almost as if it received it via ICMP. It avoids the local process who's ingress packet is rejected to have to wait for a pseudo-eternity until some timeout kicks in. Ideally, this should be enabled with a new iptables flag similar to --reject-with-sock-err For now it is enabled with CONFIG_IP*_NF_TARGET_REJECT_SKERR option. Change-Id: I649a4fd5940029ec0b3233e5abb205da6984891e Signed-off-by: JP Abgrall --- net/ipv4/netfilter/Kconfig | 12 ++++++++++++ net/ipv4/netfilter/ipt_REJECT.c | 8 ++++++++ net/ipv6/netfilter/Kconfig | 12 ++++++++++++ net/ipv6/netfilter/ip6t_REJECT.c | 9 +++++++++ 4 files changed, 41 insertions(+) diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index e7916c193932..23dfd4a312ce 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -110,6 +110,18 @@ config IP_NF_TARGET_REJECT To compile it as a module, choose M here. If unsure, say N. +config IP_NF_TARGET_REJECT_SKERR + bool "Force socket error when rejecting with icmp*" + depends on IP_NF_TARGET_REJECT + default n + help + This option enables turning a "--reject-with icmp*" into a matching + socket error also. + The REJECT target normally allows sending an ICMP message. But it + leaves the local socket unaware of any ingress rejects. + + If unsure, say N. + config IP_NF_TARGET_ULOG tristate "ULOG target support" default m if NETFILTER_ADVANCED=n diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c index 04b18c1ac345..452e8a587c34 100644 --- a/net/ipv4/netfilter/ipt_REJECT.c +++ b/net/ipv4/netfilter/ipt_REJECT.c @@ -129,6 +129,14 @@ static void send_reset(struct sk_buff *oldskb, int hook) static inline void send_unreach(struct sk_buff *skb_in, int code) { icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); +#ifdef CONFIG_IP_NF_TARGET_REJECT_SKERR + if (skb_in->sk) { + skb_in->sk->sk_err = icmp_err_convert[code].errno; + skb_in->sk->sk_error_report(skb_in->sk); + pr_debug("ipt_REJECT: sk_err=%d for skb=%p sk=%p\n", + skb_in->sk->sk_err, skb_in, skb_in->sk); + } +#endif } static unsigned int diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index 4433ab40e7de..7f45af3e8128 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -153,6 +153,18 @@ config IP6_NF_TARGET_REJECT To compile it as a module, choose M here. If unsure, say N. +config IP6_NF_TARGET_REJECT_SKERR + bool "Force socket error when rejecting with icmp*" + depends on IP6_NF_TARGET_REJECT + default n + help + This option enables turning a "--reject-with icmp*" into a matching + socket error also. + The REJECT target normally allows sending an ICMP message. But it + leaves the local socket unaware of any ingress rejects. + + If unsure, say N. + config IP6_NF_MANGLE tristate "Packet mangling" default m if NETFILTER_ADVANCED=n diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c index 70f9abc0efe9..573c232239b0 100644 --- a/net/ipv6/netfilter/ip6t_REJECT.c +++ b/net/ipv6/netfilter/ip6t_REJECT.c @@ -180,6 +180,15 @@ send_unreach(struct net *net, struct sk_buff *skb_in, unsigned char code, skb_in->dev = net->loopback_dev; icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0); +#ifdef CONFIG_IP6_NF_TARGET_REJECT_SKERR + if (skb_in->sk) { + icmpv6_err_convert(ICMPV6_DEST_UNREACH, code, + &skb_in->sk->sk_err); + skb_in->sk->sk_error_report(skb_in->sk); + pr_debug("ip6t_REJECT: sk_err=%d for skb=%p sk=%p\n", + skb_in->sk->sk_err, skb_in, skb_in->sk); + } +#endif } static unsigned int -- 2.34.1