From patchwork Wed Apr 17 20:35:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Suryaputra X-Patchwork-Id: 1087196 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="jXhhN0p8"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44kvCT2gctz9s3Z for ; Thu, 18 Apr 2019 06:36:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731789AbfDQUgT (ORCPT ); Wed, 17 Apr 2019 16:36:19 -0400 Received: from mail-it1-f195.google.com ([209.85.166.195]:35011 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727013AbfDQUgT (ORCPT ); Wed, 17 Apr 2019 16:36:19 -0400 Received: by mail-it1-f195.google.com with SMTP id w15so6633788itc.0 for ; Wed, 17 Apr 2019 13:36:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=z9KXtSolVDZ2LLw2wixNeYi+0X9hJgrrXMBWRkKWt/U=; b=jXhhN0p8T9PfCZtjoiO0bL/buajevzwxwUQCR7PyZC2VWLwUqUMoYntwc1ejwhDbKG PnK58bJPo6PvlTiJHDprIWlvprtuFrl63IgeveKoZlw8PRyZ1Ii5lZvtUvOfd8hejCTN e5FxoVE9T41GeUcVMs31xSYKkX+atTyzsnNyAfaXNS2PsW4aBITSwLYJPf4PQh4DlCzt 3egAFQbPI+t1BYJpH6o6mgf3uARLJiXtgUQ1NQ+lbbb0t72foerO/tpKkvJpwK/h0khv ZmlhA4vLRiHZC4kXTgizTWo+HV9M9gUTwuv1wI1HrY5ToHnETgAR5IkM1VGD9lKCJ6Mk NPhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=z9KXtSolVDZ2LLw2wixNeYi+0X9hJgrrXMBWRkKWt/U=; b=sUWS0SvmYZTcWNyGa6cCI78S8805GFA+Xv1pcW4lGFIWi9wDI3tnuGxL6hBHA9fniu +tS6bRR/tAQgUvQ4jywl6b8X65XtmKR/xanp9t0TSlIYAHbjNUd8RBDVp0ju/zr0mFNQ yjzsRCQ3j18KN4dPleb1wVu3vh+gW3NLat/rMHdnYpAya7X/pP3rWX3Br11bkCrO6uRk JQt1nEZwO6Ff/ICef43ABAWp5Z7YJBrC1bqLWntZFRhHMi8b1YTEiZJxpmVxsgSH9OHg q/eajQLYP8IDCR9SwfLcIw/k3zN3Kj+lLmSK05Q7geXfunxao5rZe2VXNpW1NnUF3cyA m7vA== X-Gm-Message-State: APjAAAXFynF8xXCuDbNWBGQIrqPK/tBD3JyvsWETrT5LHpWfkgBIFMYK zfV6XKlsCcfCxbxV9spnMXJGHI+AEw== X-Google-Smtp-Source: APXvYqxiegVl1JxSy58CTqvwAC0owUbsNcL2lfqsV1EjZVAdTWWwomWRXU9IbolqmPmqrpEtAlbIRg== X-Received: by 2002:a02:5143:: with SMTP id s64mr63821097jaa.54.1555533378046; Wed, 17 Apr 2019 13:36:18 -0700 (PDT) Received: from ubuntu.corp.extremenetworks.com ([12.38.14.10]) by smtp.gmail.com with ESMTPSA id r191sm33383ita.0.2019.04.17.13.36.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Apr 2019 13:36:17 -0700 (PDT) From: Stephen Suryaputra To: netdev@vger.kernel.org Cc: brouer@redhat.com, Stephen Suryaputra Subject: [PATCH net-next,v3] ipv6: Add rate limit mask for ICMPv6 messages Date: Wed, 17 Apr 2019 16:35:49 -0400 Message-Id: <20190417203549.6100-1-ssuryaextr@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org To make ICMPv6 closer to ICMPv4, add ratemask parameter. Since the ICMP message types use larger numeric values, a simple bitmask doesn't fit. I use large bitmap. The input and output are the in form of list of ranges. Set the default to rate limit all error messages but Packet Too Big. For Packet Too Big, use ratemask instead of hard-coded. There are functions where icmpv6_xrlim_allow() and icmpv6_global_allow() aren't called. This patch only adds them to icmpv6_echo_reply(). Rate limiting error messages is mandated by RFC 4443 but RFC 4890 says that it is also acceptable to rate limit informational messages. Thus, I removed the current hard-coded behavior of icmpv6_mask_allow() that doesn't rate limit informational messages. v2: Add dummy function proc_do_large_bitmap() if CONFIG_PROC_SYSCTL isn't defined, expand the description in ip-sysctl.txt and remove unnecessary conditional before kfree(). v3: Inline the bitmap instead of dynamically allocated. Still is a pointer to it is needed because of the way proc_do_large_bitmap work. Signed-off-by: Stephen Suryaputra --- Documentation/networking/ip-sysctl.txt | 17 +++++++++++++- include/net/netns/ipv6.h | 3 +++ include/uapi/linux/icmpv6.h | 4 ++++ kernel/sysctl.c | 6 +++++ net/ipv6/af_inet6.c | 9 ++++++++ net/ipv6/icmp.c | 31 ++++++++++++++++++-------- 6 files changed, 60 insertions(+), 10 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 5eedc6941ce5..8a5e59ba223f 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1913,11 +1913,26 @@ enhanced_dad - BOOLEAN icmp/*: ratelimit - INTEGER - Limit the maximal rates for sending ICMPv6 packets. + Limit the maximal rates for sending ICMPv6 messages. 0 to disable any limiting, otherwise the minimal space between responses in milliseconds. Default: 1000 +ratemask - list of comma separated ranges + For ICMPv6 message types matching the ranges in the ratemask, limit + the sending of the message according to ratelimit parameter. + + The format used for both input and output is a comma separated + list of ranges (e.g. "0-127,129" for ICMPv6 message type 0 to 127 and + 129). Writing to the file will clear all previous ranges of ICMPv6 + message types and update the current list with the input. + + Refer to: https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml + for numerical values of ICMPv6 message types, e.g. echo request is 128 + and echo reply is 129. + + Default: 0-1,3-127 (rate limit ICMPv6 errors except Packet Too Big) + echo_ignore_all - BOOLEAN If set non-zero, then the kernel will ignore all ICMP ECHO requests sent to it over the IPv6 protocol. diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 64e29b58bb5e..5e61b5a8635d 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -8,6 +8,7 @@ #ifndef __NETNS_IPV6_H__ #define __NETNS_IPV6_H__ #include +#include struct ctl_table_header; @@ -35,6 +36,8 @@ struct netns_sysctl_ipv6 { int icmpv6_echo_ignore_all; int icmpv6_echo_ignore_multicast; int icmpv6_echo_ignore_anycast; + DECLARE_BITMAP(icmpv6_ratemask, ICMPV6_MSG_MAX + 1); + unsigned long *icmpv6_ratemask_ptr; int anycast_src_echo_reply; int ip_nonlocal_bind; int fwmark_reflect; diff --git a/include/uapi/linux/icmpv6.h b/include/uapi/linux/icmpv6.h index 325395f56bfa..2622b5a3e616 100644 --- a/include/uapi/linux/icmpv6.h +++ b/include/uapi/linux/icmpv6.h @@ -90,6 +90,8 @@ struct icmp6hdr { #define ICMPV6_TIME_EXCEED 3 #define ICMPV6_PARAMPROB 4 +#define ICMPV6_ERRMSG_MAX 127 + #define ICMPV6_INFOMSG_MASK 0x80 #define ICMPV6_ECHO_REQUEST 128 @@ -110,6 +112,8 @@ struct icmp6hdr { #define ICMPV6_MRDISC_ADV 151 +#define ICMPV6_MSG_MAX 255 + /* * Codes for Destination Unreachable */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c9ec050bcf46..599510a3355e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -3326,6 +3326,11 @@ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, return -ENOSYS; } +int proc_do_large_bitmap(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + return -ENOSYS; +} #endif /* CONFIG_PROC_SYSCTL */ @@ -3366,3 +3371,4 @@ EXPORT_SYMBOL(proc_dointvec_ms_jiffies); EXPORT_SYMBOL(proc_dostring); EXPORT_SYMBOL(proc_doulongvec_minmax); EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); +EXPORT_SYMBOL(proc_do_large_bitmap); diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 1dac6ea6666a..937d95d39b0d 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -850,6 +850,15 @@ static int __net_init inet6_net_init(struct net *net) net->ipv6.sysctl.icmpv6_echo_ignore_all = 0; net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0; net->ipv6.sysctl.icmpv6_echo_ignore_anycast = 0; + + /* By default, rate limit error messages. + * Except for pmtu discovery, it would break it. + * proc_do_large_bitmap needs pointer to the bitmap. + */ + bitmap_set(net->ipv6.sysctl.icmpv6_ratemask, 0, ICMPV6_ERRMSG_MAX + 1); + bitmap_clear(net->ipv6.sysctl.icmpv6_ratemask, ICMPV6_PKT_TOOBIG, 1); + net->ipv6.sysctl.icmpv6_ratemask_ptr = net->ipv6.sysctl.icmpv6_ratemask; + net->ipv6.sysctl.flowlabel_consistency = 1; net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS; net->ipv6.sysctl.idgen_retries = 3; diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index cc14b9998941..afb915807cd0 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -168,22 +168,21 @@ static bool is_ineligible(const struct sk_buff *skb) return false; } -static bool icmpv6_mask_allow(int type) +static bool icmpv6_mask_allow(struct net *net, int type) { - /* Informational messages are not limited. */ - if (type & ICMPV6_INFOMSG_MASK) + if (type > ICMPV6_MSG_MAX) return true; - /* Do not limit pmtu discovery, it would break it. */ - if (type == ICMPV6_PKT_TOOBIG) + /* Limit if icmp type is set in ratemask. */ + if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask)) return true; return false; } -static bool icmpv6_global_allow(int type) +static bool icmpv6_global_allow(struct net *net, int type) { - if (icmpv6_mask_allow(type)) + if (icmpv6_mask_allow(net, type)) return true; if (icmp_global_allow()) @@ -202,7 +201,7 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, struct dst_entry *dst; bool res = false; - if (icmpv6_mask_allow(type)) + if (icmpv6_mask_allow(net, type)) return true; /* @@ -511,7 +510,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, local_bh_disable(); /* Check global sysctl_icmp_msgs_per_sec ratelimit */ - if (!(skb->dev->flags&IFF_LOOPBACK) && !icmpv6_global_allow(type)) + if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type)) goto out_bh_enable; mip6_addr_swap(skb); @@ -731,6 +730,11 @@ static void icmpv6_echo_reply(struct sk_buff *skb) if (IS_ERR(dst)) goto out; + /* Check the ratelimit */ + if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) || + !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6)) + goto out_dst_release; + idev = __in6_dev_get(skb->dev); msg.skb = skb; @@ -751,6 +755,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb) icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); } +out_dst_release: dst_release(dst); out: icmpv6_xmit_unlock(sk); @@ -1137,6 +1142,13 @@ static struct ctl_table ipv6_icmp_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "ratemask", + .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr, + .maxlen = ICMPV6_MSG_MAX + 1, + .mode = 0644, + .proc_handler = proc_do_large_bitmap, + }, { }, }; @@ -1153,6 +1165,7 @@ struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all; table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast; table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast; + table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr; } return table; }