Commit | Line | Data |
---|---|---|
96518518 | 1 | /* |
ef1f7df9 | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
96518518 PM |
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 { | |
dba27ec1 | 23 | u64 last; |
96518518 | 24 | u64 tokens; |
dba27ec1 | 25 | u64 tokens_max; |
96518518 | 26 | u64 rate; |
dba27ec1 | 27 | u64 nsecs; |
3e87baaf | 28 | u32 burst; |
96518518 PM |
29 | }; |
30 | ||
f8d3a6bc | 31 | static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) |
96518518 | 32 | { |
f8d3a6bc | 33 | u64 now, tokens; |
dba27ec1 | 34 | s64 delta; |
96518518 PM |
35 | |
36 | spin_lock_bh(&limit_lock); | |
dba27ec1 | 37 | now = ktime_get_ns(); |
f8d3a6bc PNA |
38 | tokens = limit->tokens + now - limit->last; |
39 | if (tokens > limit->tokens_max) | |
40 | tokens = limit->tokens_max; | |
dba27ec1 | 41 | |
f8d3a6bc | 42 | limit->last = now; |
dba27ec1 PNA |
43 | delta = tokens - cost; |
44 | if (delta >= 0) { | |
f8d3a6bc | 45 | limit->tokens = delta; |
96518518 | 46 | spin_unlock_bh(&limit_lock); |
f8d3a6bc | 47 | return false; |
96518518 | 48 | } |
f8d3a6bc | 49 | limit->tokens = tokens; |
96518518 | 50 | spin_unlock_bh(&limit_lock); |
f8d3a6bc | 51 | return true; |
96518518 PM |
52 | } |
53 | ||
f8d3a6bc | 54 | static int nft_limit_init(struct nft_limit *limit, |
96518518 PM |
55 | const struct nlattr * const tb[]) |
56 | { | |
dba27ec1 | 57 | u64 unit; |
96518518 PM |
58 | |
59 | if (tb[NFTA_LIMIT_RATE] == NULL || | |
60 | tb[NFTA_LIMIT_UNIT] == NULL) | |
61 | return -EINVAL; | |
62 | ||
f8d3a6bc | 63 | limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE])); |
dba27ec1 | 64 | unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT])); |
f8d3a6bc PNA |
65 | limit->nsecs = unit * NSEC_PER_SEC; |
66 | if (limit->rate == 0 || limit->nsecs < unit) | |
dba27ec1 | 67 | return -EOVERFLOW; |
f8d3a6bc | 68 | limit->tokens = limit->tokens_max = limit->nsecs; |
3e87baaf PNA |
69 | |
70 | if (tb[NFTA_LIMIT_BURST]) { | |
71 | u64 rate; | |
72 | ||
73 | limit->burst = ntohl(nla_get_be32(tb[NFTA_LIMIT_BURST])); | |
74 | ||
75 | rate = limit->rate + limit->burst; | |
76 | if (rate < limit->rate) | |
77 | return -EOVERFLOW; | |
78 | ||
79 | limit->rate = rate; | |
80 | } | |
f8d3a6bc PNA |
81 | limit->last = ktime_get_ns(); |
82 | ||
96518518 PM |
83 | return 0; |
84 | } | |
85 | ||
d2168e84 PNA |
86 | static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit, |
87 | enum nft_limit_type type) | |
96518518 | 88 | { |
f8d3a6bc | 89 | u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC); |
3e87baaf | 90 | u64 rate = limit->rate - limit->burst; |
96518518 | 91 | |
3e87baaf PNA |
92 | if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(rate)) || |
93 | nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs)) || | |
d2168e84 PNA |
94 | nla_put_be32(skb, NFTA_LIMIT_BURST, htonl(limit->burst)) || |
95 | nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type))) | |
96518518 PM |
96 | goto nla_put_failure; |
97 | return 0; | |
98 | ||
99 | nla_put_failure: | |
100 | return -1; | |
101 | } | |
102 | ||
8bdf3626 PNA |
103 | struct nft_limit_pkts { |
104 | struct nft_limit limit; | |
105 | u64 cost; | |
106 | }; | |
107 | ||
f8d3a6bc PNA |
108 | static void nft_limit_pkts_eval(const struct nft_expr *expr, |
109 | struct nft_regs *regs, | |
110 | const struct nft_pktinfo *pkt) | |
111 | { | |
8bdf3626 | 112 | struct nft_limit_pkts *priv = nft_expr_priv(expr); |
f8d3a6bc | 113 | |
8bdf3626 | 114 | if (nft_limit_eval(&priv->limit, priv->cost)) |
f8d3a6bc PNA |
115 | regs->verdict.code = NFT_BREAK; |
116 | } | |
117 | ||
118 | static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { | |
119 | [NFTA_LIMIT_RATE] = { .type = NLA_U64 }, | |
120 | [NFTA_LIMIT_UNIT] = { .type = NLA_U64 }, | |
3e87baaf | 121 | [NFTA_LIMIT_BURST] = { .type = NLA_U32 }, |
d2168e84 | 122 | [NFTA_LIMIT_TYPE] = { .type = NLA_U32 }, |
f8d3a6bc PNA |
123 | }; |
124 | ||
125 | static int nft_limit_pkts_init(const struct nft_ctx *ctx, | |
126 | const struct nft_expr *expr, | |
127 | const struct nlattr * const tb[]) | |
128 | { | |
8bdf3626 PNA |
129 | struct nft_limit_pkts *priv = nft_expr_priv(expr); |
130 | int err; | |
f8d3a6bc | 131 | |
8bdf3626 PNA |
132 | err = nft_limit_init(&priv->limit, tb); |
133 | if (err < 0) | |
134 | return err; | |
135 | ||
136 | priv->cost = div_u64(priv->limit.nsecs, priv->limit.rate); | |
137 | return 0; | |
f8d3a6bc PNA |
138 | } |
139 | ||
140 | static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
141 | { | |
8bdf3626 | 142 | const struct nft_limit_pkts *priv = nft_expr_priv(expr); |
f8d3a6bc | 143 | |
d2168e84 | 144 | return nft_limit_dump(skb, &priv->limit, NFT_LIMIT_PKTS); |
f8d3a6bc PNA |
145 | } |
146 | ||
ef1f7df9 | 147 | static struct nft_expr_type nft_limit_type; |
09e4e42a | 148 | static const struct nft_expr_ops nft_limit_pkts_ops = { |
ef1f7df9 | 149 | .type = &nft_limit_type, |
8bdf3626 | 150 | .size = NFT_EXPR_SIZE(sizeof(struct nft_limit_pkts)), |
09e4e42a | 151 | .eval = nft_limit_pkts_eval, |
f8d3a6bc PNA |
152 | .init = nft_limit_pkts_init, |
153 | .dump = nft_limit_pkts_dump, | |
ef1f7df9 PM |
154 | }; |
155 | ||
d2168e84 PNA |
156 | static void nft_limit_pkt_bytes_eval(const struct nft_expr *expr, |
157 | struct nft_regs *regs, | |
158 | const struct nft_pktinfo *pkt) | |
159 | { | |
160 | struct nft_limit *priv = nft_expr_priv(expr); | |
161 | u64 cost = div_u64(priv->nsecs * pkt->skb->len, priv->rate); | |
162 | ||
163 | if (nft_limit_eval(priv, cost)) | |
164 | regs->verdict.code = NFT_BREAK; | |
165 | } | |
166 | ||
167 | static int nft_limit_pkt_bytes_init(const struct nft_ctx *ctx, | |
168 | const struct nft_expr *expr, | |
169 | const struct nlattr * const tb[]) | |
170 | { | |
171 | struct nft_limit *priv = nft_expr_priv(expr); | |
172 | ||
173 | return nft_limit_init(priv, tb); | |
174 | } | |
175 | ||
176 | static int nft_limit_pkt_bytes_dump(struct sk_buff *skb, | |
177 | const struct nft_expr *expr) | |
178 | { | |
179 | const struct nft_limit *priv = nft_expr_priv(expr); | |
180 | ||
181 | return nft_limit_dump(skb, priv, NFT_LIMIT_PKT_BYTES); | |
182 | } | |
183 | ||
184 | static const struct nft_expr_ops nft_limit_pkt_bytes_ops = { | |
185 | .type = &nft_limit_type, | |
186 | .size = NFT_EXPR_SIZE(sizeof(struct nft_limit)), | |
187 | .eval = nft_limit_pkt_bytes_eval, | |
188 | .init = nft_limit_pkt_bytes_init, | |
189 | .dump = nft_limit_pkt_bytes_dump, | |
190 | }; | |
191 | ||
192 | static const struct nft_expr_ops * | |
193 | nft_limit_select_ops(const struct nft_ctx *ctx, | |
194 | const struct nlattr * const tb[]) | |
195 | { | |
196 | if (tb[NFTA_LIMIT_TYPE] == NULL) | |
197 | return &nft_limit_pkts_ops; | |
198 | ||
199 | switch (ntohl(nla_get_be32(tb[NFTA_LIMIT_TYPE]))) { | |
200 | case NFT_LIMIT_PKTS: | |
201 | return &nft_limit_pkts_ops; | |
202 | case NFT_LIMIT_PKT_BYTES: | |
203 | return &nft_limit_pkt_bytes_ops; | |
204 | } | |
205 | return ERR_PTR(-EOPNOTSUPP); | |
206 | } | |
207 | ||
ef1f7df9 PM |
208 | static struct nft_expr_type nft_limit_type __read_mostly = { |
209 | .name = "limit", | |
d2168e84 | 210 | .select_ops = nft_limit_select_ops, |
96518518 PM |
211 | .policy = nft_limit_policy, |
212 | .maxattr = NFTA_LIMIT_MAX, | |
151d799a | 213 | .flags = NFT_EXPR_STATEFUL, |
ef1f7df9 | 214 | .owner = THIS_MODULE, |
96518518 PM |
215 | }; |
216 | ||
217 | static int __init nft_limit_module_init(void) | |
218 | { | |
ef1f7df9 | 219 | return nft_register_expr(&nft_limit_type); |
96518518 PM |
220 | } |
221 | ||
222 | static void __exit nft_limit_module_exit(void) | |
223 | { | |
ef1f7df9 | 224 | nft_unregister_expr(&nft_limit_type); |
96518518 PM |
225 | } |
226 | ||
227 | module_init(nft_limit_module_init); | |
228 | module_exit(nft_limit_module_exit); | |
229 | ||
230 | MODULE_LICENSE("GPL"); | |
231 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
232 | MODULE_ALIAS_NFT_EXPR("limit"); |