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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 | /* * (C) 2007 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. */ #include <linux/module.h> #include <linux/skbuff.h> #include <linux/gen_stats.h> #include <linux/jhash.h> #include <linux/rtnetlink.h> #include <linux/random.h> #include <linux/slab.h> #include <net/gen_stats.h> #include <net/netlink.h> #include <linux/netfilter/x_tables.h> #include <linux/netfilter/xt_RATEEST.h> #include <net/netfilter/xt_rateest.h> static DEFINE_MUTEX(xt_rateest_mutex); #define RATEEST_HSIZE 16 static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly; static unsigned int jhash_rnd __read_mostly; static unsigned int xt_rateest_hash(const char *name) { return jhash(name, FIELD_SIZEOF(struct xt_rateest, name), jhash_rnd) & (RATEEST_HSIZE - 1); } static void xt_rateest_hash_insert(struct xt_rateest *est) { unsigned int h; h = xt_rateest_hash(est->name); hlist_add_head(&est->list, &rateest_hash[h]); } struct xt_rateest *xt_rateest_lookup(const char *name) { struct xt_rateest *est; unsigned int h; h = xt_rateest_hash(name); mutex_lock(&xt_rateest_mutex); hlist_for_each_entry(est, &rateest_hash[h], list) { if (strcmp(est->name, name) == 0) { est->refcnt++; mutex_unlock(&xt_rateest_mutex); return est; } } mutex_unlock(&xt_rateest_mutex); return NULL; } EXPORT_SYMBOL_GPL(xt_rateest_lookup); void xt_rateest_put(struct xt_rateest *est) { mutex_lock(&xt_rateest_mutex); if (--est->refcnt == 0) { hlist_del(&est->list); gen_kill_estimator(&est->rate_est); /* * gen_estimator est_timer() might access est->lock or bstats, * wait a RCU grace period before freeing 'est' */ kfree_rcu(est, rcu); } mutex_unlock(&xt_rateest_mutex); } EXPORT_SYMBOL_GPL(xt_rateest_put); static unsigned int xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par) { const struct xt_rateest_target_info *info = par->targinfo; struct gnet_stats_basic_packed *stats = &info->est->bstats; spin_lock_bh(&info->est->lock); stats->bytes += skb->len; stats->packets++; spin_unlock_bh(&info->est->lock); return XT_CONTINUE; } static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) { struct xt_rateest_target_info *info = par->targinfo; struct xt_rateest *est; struct { struct nlattr opt; struct gnet_estimator est; } cfg; int ret; net_get_random_once(&jhash_rnd, sizeof(jhash_rnd)); est = xt_rateest_lookup(info->name); if (est) { /* * If estimator parameters are specified, they must match the * existing estimator. */ if ((!info->interval && !info->ewma_log) || (info->interval != est->params.interval || info->ewma_log != est->params.ewma_log)) { xt_rateest_put(est); return -EINVAL; } info->est = est; return 0; } ret = -ENOMEM; est = kzalloc(sizeof(*est), GFP_KERNEL); if (!est) goto err1; strlcpy(est->name, info->name, sizeof(est->name)); spin_lock_init(&est->lock); est->refcnt = 1; est->params.interval = info->interval; est->params.ewma_log = info->ewma_log; cfg.opt.nla_len = nla_attr_size(sizeof(cfg.est)); cfg.opt.nla_type = TCA_STATS_RATE_EST; cfg.est.interval = info->interval; cfg.est.ewma_log = info->ewma_log; ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est, &est->lock, NULL, &cfg.opt); if (ret < 0) goto err2; info->est = est; xt_rateest_hash_insert(est); return 0; err2: kfree(est); err1: return ret; } static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par) { struct xt_rateest_target_info *info = par->targinfo; xt_rateest_put(info->est); } static struct xt_target xt_rateest_tg_reg __read_mostly = { .name = "RATEEST", .revision = 0, .family = NFPROTO_UNSPEC, .target = xt_rateest_tg, .checkentry = xt_rateest_tg_checkentry, .destroy = xt_rateest_tg_destroy, .targetsize = sizeof(struct xt_rateest_target_info), .usersize = offsetof(struct xt_rateest_target_info, est), .me = THIS_MODULE, }; static int __init xt_rateest_tg_init(void) { unsigned int i; for (i = 0; i < ARRAY_SIZE(rateest_hash); i++) INIT_HLIST_HEAD(&rateest_hash[i]); return xt_register_target(&xt_rateest_tg_reg); } static void __exit xt_rateest_tg_fini(void) { xt_unregister_target(&xt_rateest_tg_reg); } MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Xtables: packet rate estimator"); MODULE_ALIAS("ipt_RATEEST"); MODULE_ALIAS("ip6t_RATEEST"); module_init(xt_rateest_tg_init); module_exit(xt_rateest_tg_fini); |