From caed0ed35b1e3f3f05dfcb386bcb26df7d47f0ae Mon Sep 17 00:00:00 2001 From: Sergey Popovich Date: Sat, 2 May 2015 19:28:03 +0200 Subject: [PATCH] netfilter: ipset: Properly calculate extensions offsets and total length Offsets and total length returned by the ip_set_elem_len() calculated incorrectly as initial set element length (i.e. len parameter) is used multiple times in offset calculations, also affecting set element total length. Use initial set element length as start offset, do not add aligned extension offset to the offset. Return offset as total length of the set element. This reduces memory requirements on per element basic for the hash:* type of sets. For example output from 'ipset -terse list test-1' on 64-bit PC, where test-1 is generated via following script: #!/bin/bash set_name='test-1' ipset create "$set_name" hash:net family inet \ timeout 10800 counters comment \ hashsize 65536 maxelem 65536 declare -i o3 o4 fmt="add $set_name 192.168.%u.%u\n" for ((o3 = 0; o3 < 256; o3++)); do for ((o4 = 0; o4 < 256; o4++)); do printf "$fmt" $o3 $o4 done done |ipset -exist restore BEFORE this patch is applied # ipset -terse list test-1 Name: test-1 Type: hash:net Revision: 6 Header: family inet hashsize 65536 maxelem 65536 timeout 10800 counters comment Size in memory: 26348440 and AFTER applying patch # ipset -terse list test-1 Name: test-1 Type: hash:net Revision: 6 Header: family inet hashsize 65536 maxelem 65536 timeout 10800 counters comment Size in memory: 7706392 References: 0 Signed-off-by: Sergey Popovich Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index ed05f1e8738f..7f9c0565e715 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -365,7 +365,7 @@ size_t ip_set_elem_len(struct ip_set *set, struct nlattr *tb[], size_t len) { enum ip_set_ext_id id; - size_t offset = 0; + size_t offset = len; u32 cadt_flags = 0; if (tb[IPSET_ATTR_CADT_FLAGS]) @@ -375,12 +375,12 @@ ip_set_elem_len(struct ip_set *set, struct nlattr *tb[], size_t len) for (id = 0; id < IPSET_EXT_ID_MAX; id++) { if (!add_extension(id, cadt_flags, tb)) continue; - offset += ALIGN(len + offset, ip_set_extensions[id].align); + offset = ALIGN(offset, ip_set_extensions[id].align); set->offset[id] = offset; set->extensions |= ip_set_extensions[id].type; offset += ip_set_extensions[id].len; } - return len + offset; + return offset; } EXPORT_SYMBOL_GPL(ip_set_elem_len); -- 2.20.1