From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: Re: [PATCH next] iptables: add xt_bpf match Date: Mon, 21 Jan 2013 11:02:53 -0500 Message-ID: References: <1358529450-32413-1-git-send-email-willemb@google.com> <20130121112838.GA2907@1984> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: netfilter-devel To: Pablo Neira Ayuso Return-path: Received: from mail-ie0-f178.google.com ([209.85.223.178]:55005 "EHLO mail-ie0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752902Ab3AUQDY (ORCPT ); Mon, 21 Jan 2013 11:03:24 -0500 Received: by mail-ie0-f178.google.com with SMTP id c12so9951079ieb.37 for ; Mon, 21 Jan 2013 08:03:24 -0800 (PST) In-Reply-To: <20130121112838.GA2907@1984> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Mon, Jan 21, 2013 at 6:28 AM, Pablo Neira Ayuso wrote: > Hi Willem, > > I have applied this patch to my nf-next tree with minor changes. Great. Thanks for cleaning up the patch, Pablo. Apologies for not spotting those glitches, myself. > You'll get also another review asap for the iptables user-space part, > we have more time to get that into shape anyway. > > On Fri, Jan 18, 2013 at 12:17:30PM -0500, Willem de Bruijn wrote: >> Changes: >> - v4: fixed sparse warning and module autoloading >> - v3: reverted no longer needed changes to x_tables.c >> - v2: use a fixed size match structure to communicate between >> kernel and userspace. >> >> Support arbitrary linux socket filter (BPF) programs as iptables >> match rules. This allows for very expressive filters, and on >> platforms with BPF JIT appears competitive with traditional hardcoded >> iptables rules. >> >> At least, on an x86_64 that achieves 40K netperf TCP_STREAM without >> any iptables rules (40 GBps), >> >> inserting 100x this bpf rule gives 28K >> >> ./iptables -A OUTPUT -m bpf --bytecode '6,40 0 0 14, 21 0 3 2048,48 0 0 25,21 0 1 20,6 0 0 96,6 0 0 0,' -j > > I have removed part of the changelog, the performance part. This > filter above to be possible confusion. That filter is using the link > layer as base. > > I think the expressivity of BPF is enough to justify its inclusion > into mainline. > > I also added a line notice on the artificial limitation to 64 > instructions per filter. > > More minor glitches below. > >> inserting 100x this u32 rule gives 21K >> >> ./iptables -A OUTPUT -m u32 --u32 '6&0xFF=0x20' -j DROP >> >> The two are logically equivalent, as far as I can tell. Let me know >> if my test methodology is flawed in some way. Even in cases where >> slower, the filter adds functionality currently lacking in iptables, >> such as access to sk_buff fields like rxhash and queue_mapping. >> --- >> include/uapi/linux/netfilter/xt_bpf.h | 17 +++++++ >> net/netfilter/Kconfig | 9 ++++ >> net/netfilter/Makefile | 1 + >> net/netfilter/xt_bpf.c | 75 +++++++++++++++++++++++++++++++++ >> 4 files changed, 102 insertions(+), 0 deletions(-) >> create mode 100644 include/uapi/linux/netfilter/xt_bpf.h >> create mode 100644 net/netfilter/xt_bpf.c >> >> diff --git a/include/uapi/linux/netfilter/xt_bpf.h b/include/uapi/linux/netfilter/xt_bpf.h >> new file mode 100644 >> index 0000000..5dda450 >> --- /dev/null >> +++ b/include/uapi/linux/netfilter/xt_bpf.h >> @@ -0,0 +1,17 @@ >> +#ifndef _XT_BPF_H >> +#define _XT_BPF_H >> + >> +#include >> +#include >> + >> +#define XT_BPF_MAX_NUM_INSTR 64 >> + >> +struct xt_bpf_info { >> + __u16 bpf_program_num_elem; >> + struct sock_filter bpf_program[XT_BPF_MAX_NUM_INSTR]; >> + >> + /* only used in the kernel */ >> + struct sk_filter *filter __attribute__((aligned(8))); >> +}; >> + >> +#endif /*_XT_BPF_H */ >> diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig >> index bb48607..4017d85 100644 >> --- a/net/netfilter/Kconfig >> +++ b/net/netfilter/Kconfig >> @@ -811,6 +811,15 @@ config NETFILTER_XT_MATCH_ADDRTYPE >> If you want to compile it as a module, say M here and read >> . If unsure, say `N'. >> >> +config NETFILTER_XT_MATCH_BPF >> + tristate '"bpf" match support' >> + depends on NETFILTER_ADVANCED >> + help >> + BPF matching applies a linux socket filter to each packet and >> + accepts those for which the filter returns non-zero. > ^^^ > > Fixed this minor glitch. > >> + >> + To compile it as a module, choose M here. If unsure, say N. >> + >> config NETFILTER_XT_MATCH_CLUSTER >> tristate '"cluster" match support' >> depends on NF_CONNTRACK >> diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile >> index b3bbda6..a1abf87 100644 >> --- a/net/netfilter/Makefile >> +++ b/net/netfilter/Makefile >> @@ -99,6 +99,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_IDLETIMER) += xt_IDLETIMER.o >> >> # matches >> obj-$(CONFIG_NETFILTER_XT_MATCH_ADDRTYPE) += xt_addrtype.o >> +obj-$(CONFIG_NETFILTER_XT_MATCH_BPF) += xt_bpf.o >> obj-$(CONFIG_NETFILTER_XT_MATCH_CLUSTER) += xt_cluster.o >> obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o >> obj-$(CONFIG_NETFILTER_XT_MATCH_CONNBYTES) += xt_connbytes.o >> diff --git a/net/netfilter/xt_bpf.c b/net/netfilter/xt_bpf.c >> new file mode 100644 >> index 0000000..62d93f8 >> --- /dev/null >> +++ b/net/netfilter/xt_bpf.c >> @@ -0,0 +1,75 @@ >> +/* Xtables module to match packets using a BPF filter. >> + * Copyright 2013 Google Inc. >> + * Written by Willem de Bruijn >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include >> +#include > > Removed this header above, we don't need it. > >> +#include >> +#include > > Same thing. > >> + >> +#include >> +#include >> + >> +MODULE_AUTHOR("Willem de Bruijn "); >> +MODULE_DESCRIPTION("Xtables: BPF filter match"); >> +MODULE_LICENSE("GPL"); >> +MODULE_ALIAS("ipt_bpf"); >> +MODULE_ALIAS("ip6t_bpf"); >> + >> +static int bpf_mt_check(const struct xt_mtchk_param *par) >> +{ >> + struct xt_bpf_info *info = par->matchinfo; >> + struct sock_fprog program; >> + >> + program.len = info->bpf_program_num_elem; >> + program.filter = (struct sock_filter __user *) info->bpf_program; >> + if (sk_unattached_filter_create(&info->filter, &program)) { >> + pr_info("bpf: check failed: parse error\n"); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> + >> +static bool bpf_mt(const struct sk_buff *skb, struct xt_action_param *par) >> +{ >> + const struct xt_bpf_info *info = par->matchinfo; >> + >> + return SK_RUN_FILTER(info->filter, skb); >> +} >> + >> +static void bpf_mt_destroy(const struct xt_mtdtor_param *par) >> +{ >> + const struct xt_bpf_info *info = par->matchinfo; >> + sk_unattached_filter_destroy(info->filter); >> +} >> + >> +static struct xt_match bpf_mt_reg __read_mostly = { >> + .name = "bpf", >> + .revision = 0, >> + .family = NFPROTO_UNSPEC, >> + .checkentry = bpf_mt_check, >> + .match = bpf_mt, >> + .destroy = bpf_mt_destroy, >> + .matchsize = sizeof(struct xt_bpf_info), >> + .me = THIS_MODULE, >> +}; >> + >> +static int __init bpf_mt_init(void) >> +{ >> + return xt_register_match(&bpf_mt_reg); >> +} >> + >> +static void __exit bpf_mt_exit(void) >> +{ >> + xt_unregister_match(&bpf_mt_reg); >> +} >> + >> +module_init(bpf_mt_init); >> +module_exit(bpf_mt_exit); >> -- >> 1.7.7.3 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html