From ed13923f980ef84dde0b9010b9e09052dc31a909 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Mon, 17 May 2021 21:15:22 +0300 Subject: ipv6: Add a sysctl to control multipath hash fields A subsequent patch will add a new multipath hash policy where the packet fields used for multipath hash calculation are determined by user space. This patch adds a sysctl that allows user space to set these fields. The packet fields are represented using a bitmask and are common between IPv4 and IPv6 to allow user space to use the same numbering across both protocols. For example, to hash based on standard 5-tuple: # sysctl -w net.ipv6.fib_multipath_hash_fields=0x0037 net.ipv6.fib_multipath_hash_fields = 0x0037 To avoid introducing holes in 'struct netns_sysctl_ipv6', move the 'bindv6only' field after the multipath hash fields. The kernel rejects unknown fields, for example: # sysctl -w net.ipv6.fib_multipath_hash_fields=0x1000 sysctl: setting key "net.ipv6.fib_multipath_hash_fields": Invalid argument Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.rst | 27 +++++++++++++++++++++++++++ include/net/ipv6.h | 8 ++++++++ include/net/netns/ipv6.h | 3 ++- net/ipv6/ip6_fib.c | 5 +++++ net/ipv6/sysctl_net_ipv6.c | 12 ++++++++++++ 5 files changed, 54 insertions(+), 1 deletion(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index afdcdc0691d6..4246cc4ae35b 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -1773,6 +1773,33 @@ fib_multipath_hash_policy - INTEGER - 1 - Layer 4 (standard 5-tuple) - 2 - Layer 3 or inner Layer 3 if present +fib_multipath_hash_fields - UNSIGNED INTEGER + When fib_multipath_hash_policy is set to 3 (custom multipath hash), the + fields used for multipath hash calculation are determined by this + sysctl. + + This value is a bitmask which enables various fields for multipath hash + calculation. + + Possible fields are: + + ====== ============================ + 0x0001 Source IP address + 0x0002 Destination IP address + 0x0004 IP protocol + 0x0008 Flow Label + 0x0010 Source port + 0x0020 Destination port + 0x0040 Inner source IP address + 0x0080 Inner destination IP address + 0x0100 Inner IP protocol + 0x0200 Inner Flow Label + 0x0400 Inner source port + 0x0800 Inner destination port + ====== ============================ + + Default: 0x0007 (source IP, destination IP and IP protocol) + anycast_src_echo_reply - BOOLEAN Controls the use of anycast addresses as source addresses for ICMPv6 echo reply diff --git a/include/net/ipv6.h b/include/net/ipv6.h index 448bf2b34759..f2d0ecc257bb 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -926,11 +926,19 @@ static inline int ip6_multipath_hash_policy(const struct net *net) { return net->ipv6.sysctl.multipath_hash_policy; } +static inline u32 ip6_multipath_hash_fields(const struct net *net) +{ + return net->ipv6.sysctl.multipath_hash_fields; +} #else static inline int ip6_multipath_hash_policy(const struct net *net) { return 0; } +static inline u32 ip6_multipath_hash_fields(const struct net *net) +{ + return 0; +} #endif /* diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 6153c8067009..bde0b7adb4a3 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -28,8 +28,9 @@ struct netns_sysctl_ipv6 { int ip6_rt_gc_elasticity; int ip6_rt_mtu_expires; int ip6_rt_min_advmss; - u8 bindv6only; + u32 multipath_hash_fields; u8 multipath_hash_policy; + u8 bindv6only; u8 flowlabel_consistency; u8 auto_flowlabels; int icmpv6_time; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 33d2d6a4e28c..2d650dc24349 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -32,6 +32,7 @@ #include #include +#include #include #include @@ -2355,6 +2356,10 @@ static int __net_init fib6_net_init(struct net *net) if (err) return err; + /* Default to 3-tuple */ + net->ipv6.sysctl.multipath_hash_fields = + FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; + spin_lock_init(&net->ipv6.fib6_gc_lock); rwlock_init(&net->ipv6.fib6_walker_lock); INIT_LIST_HEAD(&net->ipv6.fib6_walkers); diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 27102c3d6e1d..ce23c8f7ceb3 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -17,6 +17,7 @@ #include #include #include +#include #ifdef CONFIG_NETLABEL #include #endif @@ -24,6 +25,8 @@ static int two = 2; static int flowlabel_reflect_max = 0x7; static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX; +static u32 rt6_multipath_hash_fields_all_mask = + FIB_MULTIPATH_HASH_FIELD_ALL_MASK; static int proc_rt6_multipath_hash_policy(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) @@ -151,6 +154,15 @@ static struct ctl_table ipv6_table_template[] = { .extra1 = SYSCTL_ZERO, .extra2 = &two, }, + { + .procname = "fib_multipath_hash_fields", + .data = &init_net.ipv6.sysctl.multipath_hash_fields, + .maxlen = sizeof(u32), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = SYSCTL_ONE, + .extra2 = &rt6_multipath_hash_fields_all_mask, + }, { .procname = "seg6_flowlabel", .data = &init_net.ipv6.sysctl.seg6_flowlabel, -- cgit v1.2.3-59-g8ed1b