cregit-Linux how code gets into the kernel

Release 4.7 net/ipv4/netfilter/nf_log_arp.c

/*
 * (C) 2014 by Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * Based on code from ebt_log from:
 *
 * Bart De Schuymer <bdschuym@pandora.be>
 * Harald Welte <laforge@netfilter.org>
 *
 * 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.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <net/route.h>

#include <linux/netfilter.h>
#include <linux/netfilter/xt_LOG.h>
#include <net/netfilter/nf_log.h>


static struct nf_loginfo default_loginfo = {
	.type	= NF_LOG_TYPE_LOG,
	.u = {
		.log = {
			.level	  = LOGLEVEL_NOTICE,
			.logflags = NF_LOG_MASK,
                },
        },
};


struct arppayload {
	
unsigned char mac_src[ETH_ALEN];
	
unsigned char ip_src[4];
	
unsigned char mac_dst[ETH_ALEN];
	
unsigned char ip_dst[4];
};


static void dump_arp_packet(struct nf_log_buf *m, const struct nf_loginfo *info, const struct sk_buff *skb, unsigned int nhoff) { const struct arphdr *ah; struct arphdr _arph; const struct arppayload *ap; struct arppayload _arpp; ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); if (ah == NULL) { nf_log_buf_add(m, "TRUNCATED"); return; } nf_log_buf_add(m, "ARP HTYPE=%d PTYPE=0x%04x OPCODE=%d", ntohs(ah->ar_hrd), ntohs(ah->ar_pro), ntohs(ah->ar_op)); /* If it's for Ethernet and the lengths are OK, then log the ARP * payload. */ if (ah->ar_hrd != htons(1) || ah->ar_hln != ETH_ALEN || ah->ar_pln != sizeof(__be32)) return; ap = skb_header_pointer(skb, sizeof(_arph), sizeof(_arpp), &_arpp); if (ap == NULL) { nf_log_buf_add(m, " INCOMPLETE [%Zu bytes]", skb->len - sizeof(_arph)); return; } nf_log_buf_add(m, " MACSRC=%pM IPSRC=%pI4 MACDST=%pM IPDST=%pI4", ap->mac_src, ap->ip_src, ap->mac_dst, ap->ip_dst); }

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pablo neira ayusopablo neira ayuso204100.00%1100.00%
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static void nf_log_arp_packet(struct net *net, u_int8_t pf, unsigned int hooknum, const struct sk_buff *skb, const struct net_device *in, const struct net_device *out, const struct nf_loginfo *loginfo, const char *prefix) { struct nf_log_buf *m; /* FIXME: Disabled from containers until syslog ns is supported */ if (!net_eq(net, &init_net)) return; m = nf_log_buf_open(); if (!loginfo) loginfo = &default_loginfo; nf_log_dump_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); dump_arp_packet(m, loginfo, skb, 0); nf_log_buf_close(m); }

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pablo neira ayusopablo neira ayuso11499.13%150.00%
florian westphalflorian westphal10.87%150.00%
Total115100.00%2100.00%

static struct nf_logger nf_arp_logger __read_mostly = { .name = "nf_log_arp", .type = NF_LOG_TYPE_LOG, .logfn = nf_log_arp_packet, .me = THIS_MODULE, };
static int __net_init nf_log_arp_net_init(struct net *net) { nf_log_set(net, NFPROTO_ARP, &nf_arp_logger); return 0; }

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pablo neira ayusopablo neira ayuso25100.00%1100.00%
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static void __net_exit nf_log_arp_net_exit(struct net *net) { nf_log_unset(net, &nf_arp_logger); }

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pablo neira ayusopablo neira ayuso20100.00%1100.00%
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static struct pernet_operations nf_log_arp_net_ops = { .init = nf_log_arp_net_init, .exit = nf_log_arp_net_exit, };
static int __init nf_log_arp_init(void) { int ret; ret = register_pernet_subsys(&nf_log_arp_net_ops); if (ret < 0) return ret; ret = nf_log_register(NFPROTO_ARP, &nf_arp_logger); if (ret < 0) { pr_err("failed to register logger\n"); goto err1; } return 0; err1: unregister_pernet_subsys(&nf_log_arp_net_ops); return ret; }

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pablo neira ayusopablo neira ayuso4057.97%150.00%
marcelo ricardo leitnermarcelo ricardo leitner2942.03%150.00%
Total69100.00%2100.00%


static void __exit nf_log_arp_exit(void) { unregister_pernet_subsys(&nf_log_arp_net_ops); nf_log_unregister(&nf_arp_logger); }

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pablo neira ayusopablo neira ayuso21100.00%1100.00%
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module_init(nf_log_arp_init); module_exit(nf_log_arp_exit); MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); MODULE_DESCRIPTION("Netfilter ARP packet logging"); MODULE_LICENSE("GPL"); MODULE_ALIAS_NF_LOGGER(3, 0);

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pablo neira ayusopablo neira ayuso59393.53%125.00%
marcelo ricardo leitnermarcelo ricardo leitner365.68%125.00%
joe perchesjoe perches40.63%125.00%
florian westphalflorian westphal10.16%125.00%
Total634100.00%4100.00%
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