From 4a3eefa399e675c4a5239497832a72733281a20f Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Mon, 2 May 2022 10:46:12 +0200 Subject: [PATCH] tcp: dynamically allocate the perturb table used by source ports [ Upstream commit e9261476184be1abd486c9434164b2acbe0ed6c2 ] We'll need to further increase the size of this table and it's likely that at some point its size will not be suitable anymore for a static table. Let's allocate it on boot from inet_hashinfo2_init(), which is called from tcp_init(). Cc: Moshe Kol Cc: Yossi Gilad Cc: Amit Klein Reviewed-by: Eric Dumazet Signed-off-by: Willy Tarreau Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/inet_hashtables.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 573a7e6..763395e 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -731,7 +731,8 @@ EXPORT_SYMBOL_GPL(inet_unhash); * privacy, this only consumes 1 KB of kernel memory. */ #define INET_TABLE_PERTURB_SHIFT 8 -static u32 table_perturb[1 << INET_TABLE_PERTURB_SHIFT]; +#define INET_TABLE_PERTURB_SIZE (1 << INET_TABLE_PERTURB_SHIFT) +static u32 *table_perturb; int __inet_hash_connect(struct inet_timewait_death_row *death_row, struct sock *sk, u64 port_offset, @@ -774,7 +775,8 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, if (likely(remaining > 1)) remaining &= ~1U; - net_get_random_once(table_perturb, sizeof(table_perturb)); + net_get_random_once(table_perturb, + INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb)); index = hash_32(port_offset, INET_TABLE_PERTURB_SHIFT); offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32); @@ -912,6 +914,12 @@ void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name, low_limit, high_limit); init_hashinfo_lhash2(h); + + /* this one is used for source ports of outgoing connections */ + table_perturb = kmalloc_array(INET_TABLE_PERTURB_SIZE, + sizeof(*table_perturb), GFP_KERNEL); + if (!table_perturb) + panic("TCP: failed to alloc table_perturb"); } int inet_hashinfo2_init_mod(struct inet_hashinfo *h) -- 2.7.4