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, const struct xt_match_param *par) 19 { 20 const struct xt_rateest_match_info *info = par->matchinfo; 21 struct gnet_stats_rate_est *r; 22 u_int32_t bps1, bps2, pps1, pps2; 23 bool ret = true; 24 25 spin_lock_bh(&info->est1->lock); 26 r = &info->est1->rstats; 27 if (info->flags & XT_RATEEST_MATCH_DELTA) { 28 bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0; 29 pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0; 30 } else { 31 bps1 = r->bps; 32 pps1 = r->pps; 33 } 34 spin_unlock_bh(&info->est1->lock); 35 36 if (info->flags & XT_RATEEST_MATCH_ABS) { 37 bps2 = info->bps2; 38 pps2 = info->pps2; 39 } else { 40 spin_lock_bh(&info->est2->lock); 41 r = &info->est2->rstats; 42 if (info->flags & XT_RATEEST_MATCH_DELTA) { 43 bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0; 44 pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0; 45 } else { 46 bps2 = r->bps; 47 pps2 = r->pps; 48 } 49 spin_unlock_bh(&info->est2->lock); 50 } 51 52 switch (info->mode) { 53 case XT_RATEEST_MATCH_LT: 54 if (info->flags & XT_RATEEST_MATCH_BPS) 55 ret &= bps1 < bps2; 56 if (info->flags & XT_RATEEST_MATCH_PPS) 57 ret &= pps1 < pps2; 58 break; 59 case XT_RATEEST_MATCH_GT: 60 if (info->flags & XT_RATEEST_MATCH_BPS) 61 ret &= bps1 > bps2; 62 if (info->flags & XT_RATEEST_MATCH_PPS) 63 ret &= pps1 > pps2; 64 break; 65 case XT_RATEEST_MATCH_EQ: 66 if (info->flags & XT_RATEEST_MATCH_BPS) 67 ret &= bps1 == bps2; 68 if (info->flags & XT_RATEEST_MATCH_PPS) 69 ret &= pps1 == pps2; 70 break; 71 } 72 73 ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false; 74 return ret; 75 } 76 77 static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par) 78 { 79 struct xt_rateest_match_info *info = par->matchinfo; 80 struct xt_rateest *est1, *est2; 81 82 if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS | 83 XT_RATEEST_MATCH_REL)) != 1) 84 goto err1; 85 86 if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS))) 87 goto err1; 88 89 switch (info->mode) { 90 case XT_RATEEST_MATCH_EQ: 91 case XT_RATEEST_MATCH_LT: 92 case XT_RATEEST_MATCH_GT: 93 break; 94 default: 95 goto err1; 96 } 97 98 est1 = xt_rateest_lookup(info->name1); 99 if (!est1) 100 goto err1; 101 102 if (info->flags & XT_RATEEST_MATCH_REL) { 103 est2 = xt_rateest_lookup(info->name2); 104 if (!est2) 105 goto err2; 106 } else 107 est2 = NULL; 108 109 110 info->est1 = est1; 111 info->est2 = est2; 112 return true; 113 114 err2: 115 xt_rateest_put(est1); 116 err1: 117 return false; 118 } 119 120 static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par) 121 { 122 struct xt_rateest_match_info *info = par->matchinfo; 123 124 xt_rateest_put(info->est1); 125 if (info->est2) 126 xt_rateest_put(info->est2); 127 } 128 129 static struct xt_match xt_rateest_mt_reg __read_mostly = { 130 .name = "rateest", 131 .revision = 0, 132 .family = NFPROTO_UNSPEC, 133 .match = xt_rateest_mt, 134 .checkentry = xt_rateest_mt_checkentry, 135 .destroy = xt_rateest_mt_destroy, 136 .matchsize = sizeof(struct xt_rateest_match_info), 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