1 /* 2 * (C) 2007 Patrick McHardy <kaber@trash.net> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 #include <linux/module.h> 9 #include <linux/skbuff.h> 10 #include <linux/gen_stats.h> 11 12 #include <linux/netfilter/x_tables.h> 13 #include <linux/netfilter/xt_rateest.h> 14 #include <net/netfilter/xt_rateest.h> 15 16 17 static bool 18 xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par) 19 { 20 const struct xt_rateest_match_info *info = par->matchinfo; 21 struct gnet_stats_rate_est64 sample = {0}; 22 u_int32_t bps1, bps2, pps1, pps2; 23 bool ret = true; 24 25 gen_estimator_read(&info->est1->rate_est, &sample); 26 27 if (info->flags & XT_RATEEST_MATCH_DELTA) { 28 bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0; 29 pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0; 30 } else { 31 bps1 = sample.bps; 32 pps1 = sample.pps; 33 } 34 35 if (info->flags & XT_RATEEST_MATCH_ABS) { 36 bps2 = info->bps2; 37 pps2 = info->pps2; 38 } else { 39 gen_estimator_read(&info->est2->rate_est, &sample); 40 41 if (info->flags & XT_RATEEST_MATCH_DELTA) { 42 bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0; 43 pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0; 44 } else { 45 bps2 = sample.bps; 46 pps2 = sample.pps; 47 } 48 } 49 50 switch (info->mode) { 51 case XT_RATEEST_MATCH_LT: 52 if (info->flags & XT_RATEEST_MATCH_BPS) 53 ret &= bps1 < bps2; 54 if (info->flags & XT_RATEEST_MATCH_PPS) 55 ret &= pps1 < pps2; 56 break; 57 case XT_RATEEST_MATCH_GT: 58 if (info->flags & XT_RATEEST_MATCH_BPS) 59 ret &= bps1 > bps2; 60 if (info->flags & XT_RATEEST_MATCH_PPS) 61 ret &= pps1 > pps2; 62 break; 63 case XT_RATEEST_MATCH_EQ: 64 if (info->flags & XT_RATEEST_MATCH_BPS) 65 ret &= bps1 == bps2; 66 if (info->flags & XT_RATEEST_MATCH_PPS) 67 ret &= pps1 == pps2; 68 break; 69 } 70 71 ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false; 72 return ret; 73 } 74 75 static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par) 76 { 77 struct xt_rateest_match_info *info = par->matchinfo; 78 struct xt_rateest *est1, *est2; 79 int ret = -EINVAL; 80 81 if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS | 82 XT_RATEEST_MATCH_REL)) != 1) 83 goto err1; 84 85 if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS))) 86 goto err1; 87 88 switch (info->mode) { 89 case XT_RATEEST_MATCH_EQ: 90 case XT_RATEEST_MATCH_LT: 91 case XT_RATEEST_MATCH_GT: 92 break; 93 default: 94 goto err1; 95 } 96 97 ret = -ENOENT; 98 est1 = xt_rateest_lookup(info->name1); 99 if (!est1) 100 goto err1; 101 102 est2 = NULL; 103 if (info->flags & XT_RATEEST_MATCH_REL) { 104 est2 = xt_rateest_lookup(info->name2); 105 if (!est2) 106 goto err2; 107 } 108 109 info->est1 = est1; 110 info->est2 = est2; 111 return 0; 112 113 err2: 114 xt_rateest_put(est1); 115 err1: 116 return ret; 117 } 118 119 static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par) 120 { 121 struct xt_rateest_match_info *info = par->matchinfo; 122 123 xt_rateest_put(info->est1); 124 if (info->est2) 125 xt_rateest_put(info->est2); 126 } 127 128 static struct xt_match xt_rateest_mt_reg __read_mostly = { 129 .name = "rateest", 130 .revision = 0, 131 .family = NFPROTO_UNSPEC, 132 .match = xt_rateest_mt, 133 .checkentry = xt_rateest_mt_checkentry, 134 .destroy = xt_rateest_mt_destroy, 135 .matchsize = sizeof(struct xt_rateest_match_info), 136 .usersize = offsetof(struct xt_rateest_match_info, est1), 137 .me = THIS_MODULE, 138 }; 139 140 static int __init xt_rateest_mt_init(void) 141 { 142 return xt_register_match(&xt_rateest_mt_reg); 143 } 144 145 static void __exit xt_rateest_mt_fini(void) 146 { 147 xt_unregister_match(&xt_rateest_mt_reg); 148 } 149 150 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 151 MODULE_LICENSE("GPL"); 152 MODULE_DESCRIPTION("xtables rate estimator match"); 153 MODULE_ALIAS("ipt_rateest"); 154 MODULE_ALIAS("ip6t_rateest"); 155 module_init(xt_rateest_mt_init); 156 module_exit(xt_rateest_mt_fini); 157