From d0941130c93515411c8d66fc22bdae407b509a6d Mon Sep 17 00:00:00 2001 From: Jamie Bainbridge Date: Wed, 25 Jan 2023 11:16:52 +1100 Subject: [PATCH] icmp: Add counters for rate limits There are multiple ICMP rate limiting mechanisms: * Global limits: net.ipv4.icmp_msgs_burst/icmp_msgs_per_sec * v4 per-host limits: net.ipv4.icmp_ratelimit/ratemask * v6 per-host limits: net.ipv6.icmp_ratelimit/ratemask However, when ICMP output is limited, there is no way to tell which limit has been hit or even if the limits are responsible for the lack of ICMP output. Add counters for each of the cases above. As we are within local_bh_disable(), use the __INC stats variant. Example output: # nstat -sz "*RateLimit*" IcmpOutRateLimitGlobal 134 0.0 IcmpOutRateLimitHost 770 0.0 Icmp6OutRateLimitHost 84 0.0 Signed-off-by: Jamie Bainbridge Suggested-by: Abhishek Rawal Link: https://lore.kernel.org/r/273b32241e6b7fdc5c609e6f5ebc68caf3994342.1674605770.git.jamie.bainbridge@gmail.com Signed-off-by: Paolo Abeni --- include/uapi/linux/snmp.h | 3 +++ net/ipv4/icmp.c | 3 +++ net/ipv4/proc.c | 8 +++++--- net/ipv6/icmp.c | 4 ++++ net/ipv6/proc.c | 1 + 5 files changed, 16 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h index 6600cb0..26f33a4 100644 --- a/include/uapi/linux/snmp.h +++ b/include/uapi/linux/snmp.h @@ -95,6 +95,8 @@ enum ICMP_MIB_OUTADDRMASKS, /* OutAddrMasks */ ICMP_MIB_OUTADDRMASKREPS, /* OutAddrMaskReps */ ICMP_MIB_CSUMERRORS, /* InCsumErrors */ + ICMP_MIB_RATELIMITGLOBAL, /* OutRateLimitGlobal */ + ICMP_MIB_RATELIMITHOST, /* OutRateLimitHost */ __ICMP_MIB_MAX }; @@ -112,6 +114,7 @@ enum ICMP6_MIB_OUTMSGS, /* OutMsgs */ ICMP6_MIB_OUTERRORS, /* OutErrors */ ICMP6_MIB_CSUMERRORS, /* InCsumErrors */ + ICMP6_MIB_RATELIMITHOST, /* OutRateLimitHost */ __ICMP6_MIB_MAX }; diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 46aa2d6..8cebb47 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -296,6 +296,7 @@ static bool icmpv4_global_allow(struct net *net, int type, int code) if (icmp_global_allow()) return true; + __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -325,6 +326,8 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, if (peer) inet_putpeer(peer); out: + if (!rc) + __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITHOST); return rc; } diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index f88daac..eaf1d31 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -353,7 +353,7 @@ static void icmp_put(struct seq_file *seq) seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors"); for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " In%s", icmpmibmap[i].name); - seq_puts(seq, " OutMsgs OutErrors"); + seq_puts(seq, " OutMsgs OutErrors OutRateLimitGlobal OutRateLimitHost"); for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " Out%s", icmpmibmap[i].name); seq_printf(seq, "\nIcmp: %lu %lu %lu", @@ -363,9 +363,11 @@ static void icmp_put(struct seq_file *seq) for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " %lu", atomic_long_read(ptr + icmpmibmap[i].index)); - seq_printf(seq, " %lu %lu", + seq_printf(seq, " %lu %lu %lu %lu", snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS), - snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS)); + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS), + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_RATELIMITGLOBAL), + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_RATELIMITHOST)); for (i = 0; icmpmibmap[i].name; i++) seq_printf(seq, " %lu", atomic_long_read(ptr + (icmpmibmap[i].index | 0x100))); diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 9d92d51..79c769c 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -183,6 +183,7 @@ static bool icmpv6_global_allow(struct net *net, int type) if (icmp_global_allow()) return true; + __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); return false; } @@ -224,6 +225,9 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, if (peer) inet_putpeer(peer); } + if (!res) + __ICMP6_INC_STATS(net, ip6_dst_idev(dst), + ICMP6_MIB_RATELIMITHOST); dst_release(dst); return res; } diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c index d6306aa..e20b370 100644 --- a/net/ipv6/proc.c +++ b/net/ipv6/proc.c @@ -94,6 +94,7 @@ static const struct snmp_mib snmp6_icmp6_list[] = { SNMP_MIB_ITEM("Icmp6OutMsgs", ICMP6_MIB_OUTMSGS), SNMP_MIB_ITEM("Icmp6OutErrors", ICMP6_MIB_OUTERRORS), SNMP_MIB_ITEM("Icmp6InCsumErrors", ICMP6_MIB_CSUMERRORS), + SNMP_MIB_ITEM("Icmp6OutRateLimitHost", ICMP6_MIB_RATELIMITHOST), SNMP_MIB_SENTINEL }; -- 2.7.4