Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 1 | /* |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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 | * Development of this code funded by Astaro AG (http://www.astaro.com/) |
| 9 | */ |
| 10 | |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/spinlock.h> |
| 15 | #include <linux/netlink.h> |
| 16 | #include <linux/netfilter.h> |
| 17 | #include <linux/netfilter/nf_tables.h> |
| 18 | #include <net/netfilter/nf_tables.h> |
| 19 | |
| 20 | static DEFINE_SPINLOCK(limit_lock); |
| 21 | |
| 22 | struct nft_limit { |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 23 | u64 last; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 24 | u64 tokens; |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 25 | u64 tokens_max; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 26 | u64 rate; |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 27 | u64 nsecs; |
Pablo Neira Ayuso | 3e87baa | 2015-08-02 18:02:14 +0200 | [diff] [blame] | 28 | u32 burst; |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 29 | bool invert; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 30 | }; |
| 31 | |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 32 | static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 33 | { |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 34 | u64 now, tokens; |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 35 | s64 delta; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 36 | |
| 37 | spin_lock_bh(&limit_lock); |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 38 | now = ktime_get_ns(); |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 39 | tokens = limit->tokens + now - limit->last; |
| 40 | if (tokens > limit->tokens_max) |
| 41 | tokens = limit->tokens_max; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 42 | |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 43 | limit->last = now; |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 44 | delta = tokens - cost; |
| 45 | if (delta >= 0) { |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 46 | limit->tokens = delta; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 47 | spin_unlock_bh(&limit_lock); |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 48 | return limit->invert; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 49 | } |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 50 | limit->tokens = tokens; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 51 | spin_unlock_bh(&limit_lock); |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 52 | return !limit->invert; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 53 | } |
| 54 | |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 55 | static int nft_limit_init(struct nft_limit *limit, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 56 | const struct nlattr * const tb[]) |
| 57 | { |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 58 | u64 unit; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 59 | |
| 60 | if (tb[NFTA_LIMIT_RATE] == NULL || |
| 61 | tb[NFTA_LIMIT_UNIT] == NULL) |
| 62 | return -EINVAL; |
| 63 | |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 64 | limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE])); |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 65 | unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT])); |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 66 | limit->nsecs = unit * NSEC_PER_SEC; |
| 67 | if (limit->rate == 0 || limit->nsecs < unit) |
Pablo Neira Ayuso | dba27ec | 2015-07-31 14:10:22 +0200 | [diff] [blame] | 68 | return -EOVERFLOW; |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 69 | limit->tokens = limit->tokens_max = limit->nsecs; |
Pablo Neira Ayuso | 3e87baa | 2015-08-02 18:02:14 +0200 | [diff] [blame] | 70 | |
| 71 | if (tb[NFTA_LIMIT_BURST]) { |
| 72 | u64 rate; |
| 73 | |
| 74 | limit->burst = ntohl(nla_get_be32(tb[NFTA_LIMIT_BURST])); |
| 75 | |
| 76 | rate = limit->rate + limit->burst; |
| 77 | if (rate < limit->rate) |
| 78 | return -EOVERFLOW; |
| 79 | |
| 80 | limit->rate = rate; |
| 81 | } |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 82 | if (tb[NFTA_LIMIT_FLAGS]) { |
| 83 | u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS])); |
| 84 | |
| 85 | if (flags & NFT_LIMIT_F_INV) |
| 86 | limit->invert = true; |
| 87 | } |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 88 | limit->last = ktime_get_ns(); |
| 89 | |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 90 | return 0; |
| 91 | } |
| 92 | |
Pablo Neira Ayuso | d2168e8 | 2015-08-05 12:38:44 +0200 | [diff] [blame] | 93 | static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit, |
| 94 | enum nft_limit_type type) |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 95 | { |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 96 | u32 flags = limit->invert ? NFT_LIMIT_F_INV : 0; |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 97 | u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC); |
Pablo Neira Ayuso | 3e87baa | 2015-08-02 18:02:14 +0200 | [diff] [blame] | 98 | u64 rate = limit->rate - limit->burst; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 99 | |
Pablo Neira Ayuso | 3e87baa | 2015-08-02 18:02:14 +0200 | [diff] [blame] | 100 | if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(rate)) || |
| 101 | nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs)) || |
Pablo Neira Ayuso | d2168e8 | 2015-08-05 12:38:44 +0200 | [diff] [blame] | 102 | nla_put_be32(skb, NFTA_LIMIT_BURST, htonl(limit->burst)) || |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 103 | nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type)) || |
| 104 | nla_put_be32(skb, NFTA_LIMIT_FLAGS, htonl(flags))) |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 105 | goto nla_put_failure; |
| 106 | return 0; |
| 107 | |
| 108 | nla_put_failure: |
| 109 | return -1; |
| 110 | } |
| 111 | |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 112 | struct nft_limit_pkts { |
| 113 | struct nft_limit limit; |
| 114 | u64 cost; |
| 115 | }; |
| 116 | |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 117 | static void nft_limit_pkts_eval(const struct nft_expr *expr, |
| 118 | struct nft_regs *regs, |
| 119 | const struct nft_pktinfo *pkt) |
| 120 | { |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 121 | struct nft_limit_pkts *priv = nft_expr_priv(expr); |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 122 | |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 123 | if (nft_limit_eval(&priv->limit, priv->cost)) |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 124 | regs->verdict.code = NFT_BREAK; |
| 125 | } |
| 126 | |
| 127 | static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { |
| 128 | [NFTA_LIMIT_RATE] = { .type = NLA_U64 }, |
| 129 | [NFTA_LIMIT_UNIT] = { .type = NLA_U64 }, |
Pablo Neira Ayuso | 3e87baa | 2015-08-02 18:02:14 +0200 | [diff] [blame] | 130 | [NFTA_LIMIT_BURST] = { .type = NLA_U32 }, |
Pablo Neira Ayuso | d2168e8 | 2015-08-05 12:38:44 +0200 | [diff] [blame] | 131 | [NFTA_LIMIT_TYPE] = { .type = NLA_U32 }, |
Pablo Neira Ayuso | c7862a5 | 2015-12-28 18:21:44 +0100 | [diff] [blame] | 132 | [NFTA_LIMIT_FLAGS] = { .type = NLA_U32 }, |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 133 | }; |
| 134 | |
| 135 | static int nft_limit_pkts_init(const struct nft_ctx *ctx, |
| 136 | const struct nft_expr *expr, |
| 137 | const struct nlattr * const tb[]) |
| 138 | { |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 139 | struct nft_limit_pkts *priv = nft_expr_priv(expr); |
| 140 | int err; |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 141 | |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 142 | err = nft_limit_init(&priv->limit, tb); |
| 143 | if (err < 0) |
| 144 | return err; |
| 145 | |
| 146 | priv->cost = div_u64(priv->limit.nsecs, priv->limit.rate); |
| 147 | return 0; |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 148 | } |
| 149 | |
| 150 | static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 151 | { |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 152 | const struct nft_limit_pkts *priv = nft_expr_priv(expr); |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 153 | |
Pablo Neira Ayuso | d2168e8 | 2015-08-05 12:38:44 +0200 | [diff] [blame] | 154 | return nft_limit_dump(skb, &priv->limit, NFT_LIMIT_PKTS); |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 155 | } |
| 156 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 157 | static struct nft_expr_type nft_limit_type; |
Pablo Neira Ayuso | 09e4e42 | 2015-07-31 14:16:51 +0200 | [diff] [blame] | 158 | static const struct nft_expr_ops nft_limit_pkts_ops = { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 159 | .type = &nft_limit_type, |
Pablo Neira Ayuso | 8bdf362 | 2015-08-02 14:24:24 +0200 | [diff] [blame] | 160 | .size = NFT_EXPR_SIZE(sizeof(struct nft_limit_pkts)), |
Pablo Neira Ayuso | 09e4e42 | 2015-07-31 14:16:51 +0200 | [diff] [blame] | 161 | .eval = nft_limit_pkts_eval, |
Pablo Neira Ayuso | f8d3a6b | 2015-08-02 14:16:42 +0200 | [diff] [blame] | 162 | .init = nft_limit_pkts_init, |
| 163 | .dump = nft_limit_pkts_dump, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 164 | }; |
| 165 | |
Pablo Neira Ayuso | d2168e8 | 2015-08-05 12:38:44 +0200 | [diff] [blame] | 166 | static void nft_limit_pkt_bytes_eval(const struct nft_expr *expr, |
| 167 | struct nft_regs *regs, |
| 168 | const struct nft_pktinfo *pkt) |
| 169 | { |
| 170 | struct nft_limit *priv = nft_expr_priv(expr); |
| 171 | u64 cost = div_u64(priv->nsecs * pkt->skb->len, priv->rate); |
| 172 | |
| 173 | if (nft_limit_eval(priv, cost)) |
| 174 | regs->verdict.code = NFT_BREAK; |
| 175 | } |
| 176 | |
| 177 | static int nft_limit_pkt_bytes_init(const struct nft_ctx *ctx, |
| 178 | const struct nft_expr *expr, |
| 179 | const struct nlattr * const tb[]) |
| 180 | { |
| 181 | struct nft_limit *priv = nft_expr_priv(expr); |
| 182 | |
| 183 | return nft_limit_init(priv, tb); |
| 184 | } |
| 185 | |
| 186 | static int nft_limit_pkt_bytes_dump(struct sk_buff *skb, |
| 187 | const struct nft_expr *expr) |
| 188 | { |
| 189 | const struct nft_limit *priv = nft_expr_priv(expr); |
| 190 | |
| 191 | return nft_limit_dump(skb, priv, NFT_LIMIT_PKT_BYTES); |
| 192 | } |
| 193 | |
| 194 | static const struct nft_expr_ops nft_limit_pkt_bytes_ops = { |
| 195 | .type = &nft_limit_type, |
| 196 | .size = NFT_EXPR_SIZE(sizeof(struct nft_limit)), |
| 197 | .eval = nft_limit_pkt_bytes_eval, |
| 198 | .init = nft_limit_pkt_bytes_init, |
| 199 | .dump = nft_limit_pkt_bytes_dump, |
| 200 | }; |
| 201 | |
| 202 | static const struct nft_expr_ops * |
| 203 | nft_limit_select_ops(const struct nft_ctx *ctx, |
| 204 | const struct nlattr * const tb[]) |
| 205 | { |
| 206 | if (tb[NFTA_LIMIT_TYPE] == NULL) |
| 207 | return &nft_limit_pkts_ops; |
| 208 | |
| 209 | switch (ntohl(nla_get_be32(tb[NFTA_LIMIT_TYPE]))) { |
| 210 | case NFT_LIMIT_PKTS: |
| 211 | return &nft_limit_pkts_ops; |
| 212 | case NFT_LIMIT_PKT_BYTES: |
| 213 | return &nft_limit_pkt_bytes_ops; |
| 214 | } |
| 215 | return ERR_PTR(-EOPNOTSUPP); |
| 216 | } |
| 217 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 218 | static struct nft_expr_type nft_limit_type __read_mostly = { |
| 219 | .name = "limit", |
Pablo Neira Ayuso | d2168e8 | 2015-08-05 12:38:44 +0200 | [diff] [blame] | 220 | .select_ops = nft_limit_select_ops, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 221 | .policy = nft_limit_policy, |
| 222 | .maxattr = NFTA_LIMIT_MAX, |
Patrick McHardy | 151d799 | 2015-04-11 10:46:40 +0100 | [diff] [blame] | 223 | .flags = NFT_EXPR_STATEFUL, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 224 | .owner = THIS_MODULE, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 225 | }; |
| 226 | |
| 227 | static int __init nft_limit_module_init(void) |
| 228 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 229 | return nft_register_expr(&nft_limit_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 230 | } |
| 231 | |
| 232 | static void __exit nft_limit_module_exit(void) |
| 233 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 234 | nft_unregister_expr(&nft_limit_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 235 | } |
| 236 | |
| 237 | module_init(nft_limit_module_init); |
| 238 | module_exit(nft_limit_module_exit); |
| 239 | |
| 240 | MODULE_LICENSE("GPL"); |
| 241 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 242 | MODULE_ALIAS_NFT_EXPR("limit"); |