cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/xt_statistic.c

Directory: net/netfilter
/*
 * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
 *
 * 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.
 *
 * Based on ipt_random and ipt_nth by Fabrice MARIE <fabrice@netfilter.org>.
 */

#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/slab.h>

#include <linux/netfilter/xt_statistic.h>
#include <linux/netfilter/x_tables.h>
#include <linux/module.h>


struct xt_statistic_priv {
	
atomic_t count;
} 
____cacheline_aligned_in_smp;

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("Xtables: statistics-based matching (\"Nth\", random)");
MODULE_ALIAS("ipt_statistic");
MODULE_ALIAS("ip6t_statistic");


static bool statistic_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct xt_statistic_info *info = par->matchinfo; bool ret = info->flags & XT_STATISTIC_INVERT; int nval, oval; switch (info->mode) { case XT_STATISTIC_MODE_RANDOM: if ((prandom_u32() & 0x7FFFFFFF) < info->u.random.probability) ret = !ret; break; case XT_STATISTIC_MODE_NTH: do { oval = atomic_read(&info->master->count); nval = (oval == info->u.nth.every) ? 0 : oval + 1; } while (atomic_cmpxchg(&info->master->count, oval, nval) != oval); if (nval == 0) ret = !ret; break; } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy8457.14%112.50%
Eric Dumazet4429.93%112.50%
Jan Engelhardt1812.24%562.50%
Aruna-Hewapathirane10.68%112.50%
Total147100.00%8100.00%


static int statistic_mt_check(const struct xt_mtchk_param *par) { struct xt_statistic_info *info = par->matchinfo; if (info->mode > XT_STATISTIC_MODE_MAX || info->flags & ~XT_STATISTIC_MASK) return -EINVAL; info->master = kzalloc(sizeof(*info->master), GFP_KERNEL); if (info->master == NULL) return -ENOMEM; atomic_set(&info->master->count, info->u.nth.count); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt4550.00%675.00%
Patrick McHardy4044.44%112.50%
Eric Dumazet55.56%112.50%
Total90100.00%8100.00%


static void statistic_mt_destroy(const struct xt_mtdtor_param *par) { const struct xt_statistic_info *info = par->matchinfo; kfree(info->master); }

Contributors

PersonTokensPropCommitsCommitProp
Jan Engelhardt29100.00%1100.00%
Total29100.00%1100.00%

static struct xt_match xt_statistic_mt_reg __read_mostly = { .name = "statistic", .revision = 0, .family = NFPROTO_UNSPEC, .match = statistic_mt, .checkentry = statistic_mt_check, .destroy = statistic_mt_destroy, .matchsize = sizeof(struct xt_statistic_info), .me = THIS_MODULE, };
static int __init statistic_mt_init(void) { return xt_register_match(&xt_statistic_mt_reg); }

Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy1275.00%250.00%
Jan Engelhardt425.00%250.00%
Total16100.00%4100.00%


static void __exit statistic_mt_exit(void) { xt_unregister_match(&xt_statistic_mt_reg); }

Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy1173.33%133.33%
Jan Engelhardt426.67%266.67%
Total15100.00%3100.00%

module_init(statistic_mt_init); module_exit(statistic_mt_exit);

Overall Contributors

PersonTokensPropCommitsCommitProp
Patrick McHardy23856.94%316.67%
Jan Engelhardt12229.19%1161.11%
Eric Dumazet5112.20%15.56%
Tejun Heo30.72%15.56%
Paul Gortmaker30.72%15.56%
Aruna-Hewapathirane10.24%15.56%
Total418100.00%18100.00%
Directory: net/netfilter
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