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11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/list.h>
15#include <linux/rculist.h>
16#include <linux/skbuff.h>
17#include <linux/netlink.h>
18#include <linux/netfilter.h>
19#include <linux/static_key.h>
20#include <linux/netfilter/nfnetlink.h>
21#include <linux/netfilter/nf_tables.h>
22#include <net/netfilter/nf_tables_core.h>
23#include <net/netfilter/nf_tables.h>
24#include <net/netfilter/nf_log.h>
25
26static const char *const comments[__NFT_TRACETYPE_MAX] = {
27 [NFT_TRACETYPE_POLICY] = "policy",
28 [NFT_TRACETYPE_RETURN] = "return",
29 [NFT_TRACETYPE_RULE] = "rule",
30};
31
32static struct nf_loginfo trace_loginfo = {
33 .type = NF_LOG_TYPE_LOG,
34 .u = {
35 .log = {
36 .level = LOGLEVEL_WARNING,
37 .logflags = NF_LOG_MASK,
38 },
39 },
40};
41
42static noinline void __nft_trace_packet(struct nft_traceinfo *info,
43 const struct nft_chain *chain,
44 int rulenum, enum nft_trace_types type)
45{
46 const struct nft_pktinfo *pkt = info->pkt;
47
48 if (!info->trace || !pkt->skb->nf_trace)
49 return;
50
51 info->chain = chain;
52 info->type = type;
53
54 nft_trace_notify(info);
55
56 nf_log_trace(pkt->net, pkt->pf, pkt->hook, pkt->skb, pkt->in,
57 pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
58 chain->table->name, chain->name, comments[type],
59 rulenum);
60}
61
62static inline void nft_trace_packet(struct nft_traceinfo *info,
63 const struct nft_chain *chain,
64 const struct nft_rule *rule,
65 int rulenum,
66 enum nft_trace_types type)
67{
68 if (static_branch_unlikely(&nft_trace_enabled)) {
69 info->rule = rule;
70 __nft_trace_packet(info, chain, rulenum, type);
71 }
72}
73
74static void nft_cmp_fast_eval(const struct nft_expr *expr,
75 struct nft_regs *regs)
76{
77 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
78 u32 mask = nft_cmp_fast_mask(priv->len);
79
80 if ((regs->data[priv->sreg] & mask) == priv->data)
81 return;
82 regs->verdict.code = NFT_BREAK;
83}
84
85static bool nft_payload_fast_eval(const struct nft_expr *expr,
86 struct nft_regs *regs,
87 const struct nft_pktinfo *pkt)
88{
89 const struct nft_payload *priv = nft_expr_priv(expr);
90 const struct sk_buff *skb = pkt->skb;
91 u32 *dest = ®s->data[priv->dreg];
92 unsigned char *ptr;
93
94 if (priv->base == NFT_PAYLOAD_NETWORK_HEADER)
95 ptr = skb_network_header(skb);
96 else
97 ptr = skb_network_header(skb) + pkt->xt.thoff;
98
99 ptr += priv->offset;
100
101 if (unlikely(ptr + priv->len >= skb_tail_pointer(skb)))
102 return false;
103
104 *dest = 0;
105 if (priv->len == 2)
106 *(u16 *)dest = *(u16 *)ptr;
107 else if (priv->len == 4)
108 *(u32 *)dest = *(u32 *)ptr;
109 else
110 *(u8 *)dest = *(u8 *)ptr;
111 return true;
112}
113
114struct nft_jumpstack {
115 const struct nft_chain *chain;
116 const struct nft_rule *rule;
117 int rulenum;
118};
119
120unsigned int
121nft_do_chain(struct nft_pktinfo *pkt, void *priv)
122{
123 const struct nft_chain *chain = priv, *basechain = chain;
124 const struct net *net = pkt->net;
125 const struct nft_rule *rule;
126 const struct nft_expr *expr, *last;
127 struct nft_regs regs;
128 unsigned int stackptr = 0;
129 struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
130 struct nft_stats *stats;
131 int rulenum;
132 unsigned int gencursor = nft_genmask_cur(net);
133 struct nft_traceinfo info;
134
135 info.trace = false;
136 if (static_branch_unlikely(&nft_trace_enabled))
137 nft_trace_init(&info, pkt, ®s.verdict, basechain);
138do_chain:
139 rulenum = 0;
140 rule = list_entry(&chain->rules, struct nft_rule, list);
141next_rule:
142 regs.verdict.code = NFT_CONTINUE;
143 list_for_each_entry_continue_rcu(rule, &chain->rules, list) {
144
145
146 if (unlikely(rule->genmask & (1 << gencursor)))
147 continue;
148
149 rulenum++;
150
151 nft_rule_for_each_expr(expr, last, rule) {
152 if (expr->ops == &nft_cmp_fast_ops)
153 nft_cmp_fast_eval(expr, ®s);
154 else if (expr->ops != &nft_payload_fast_ops ||
155 !nft_payload_fast_eval(expr, ®s, pkt))
156 expr->ops->eval(expr, ®s, pkt);
157
158 if (regs.verdict.code != NFT_CONTINUE)
159 break;
160 }
161
162 switch (regs.verdict.code) {
163 case NFT_BREAK:
164 regs.verdict.code = NFT_CONTINUE;
165 continue;
166 case NFT_CONTINUE:
167 nft_trace_packet(&info, chain, rule,
168 rulenum, NFT_TRACETYPE_RULE);
169 continue;
170 }
171 break;
172 }
173
174 switch (regs.verdict.code & NF_VERDICT_MASK) {
175 case NF_ACCEPT:
176 case NF_DROP:
177 case NF_QUEUE:
178 nft_trace_packet(&info, chain, rule,
179 rulenum, NFT_TRACETYPE_RULE);
180 return regs.verdict.code;
181 }
182
183 switch (regs.verdict.code) {
184 case NFT_JUMP:
185 BUG_ON(stackptr >= NFT_JUMP_STACK_SIZE);
186 jumpstack[stackptr].chain = chain;
187 jumpstack[stackptr].rule = rule;
188 jumpstack[stackptr].rulenum = rulenum;
189 stackptr++;
190
191 case NFT_GOTO:
192 nft_trace_packet(&info, chain, rule,
193 rulenum, NFT_TRACETYPE_RULE);
194
195 chain = regs.verdict.chain;
196 goto do_chain;
197 case NFT_CONTINUE:
198 rulenum++;
199
200 case NFT_RETURN:
201 nft_trace_packet(&info, chain, rule,
202 rulenum, NFT_TRACETYPE_RETURN);
203 break;
204 default:
205 WARN_ON(1);
206 }
207
208 if (stackptr > 0) {
209 stackptr--;
210 chain = jumpstack[stackptr].chain;
211 rule = jumpstack[stackptr].rule;
212 rulenum = jumpstack[stackptr].rulenum;
213 goto next_rule;
214 }
215
216 nft_trace_packet(&info, basechain, NULL, -1,
217 NFT_TRACETYPE_POLICY);
218
219 rcu_read_lock_bh();
220 stats = this_cpu_ptr(rcu_dereference(nft_base_chain(basechain)->stats));
221 u64_stats_update_begin(&stats->syncp);
222 stats->pkts++;
223 stats->bytes += pkt->skb->len;
224 u64_stats_update_end(&stats->syncp);
225 rcu_read_unlock_bh();
226
227 return nft_base_chain(basechain)->policy;
228}
229EXPORT_SYMBOL_GPL(nft_do_chain);
230
231int __init nf_tables_core_module_init(void)
232{
233 int err;
234
235 err = nft_immediate_module_init();
236 if (err < 0)
237 goto err1;
238
239 err = nft_cmp_module_init();
240 if (err < 0)
241 goto err2;
242
243 err = nft_lookup_module_init();
244 if (err < 0)
245 goto err3;
246
247 err = nft_bitwise_module_init();
248 if (err < 0)
249 goto err4;
250
251 err = nft_byteorder_module_init();
252 if (err < 0)
253 goto err5;
254
255 err = nft_payload_module_init();
256 if (err < 0)
257 goto err6;
258
259 err = nft_dynset_module_init();
260 if (err < 0)
261 goto err7;
262
263 return 0;
264
265err7:
266 nft_payload_module_exit();
267err6:
268 nft_byteorder_module_exit();
269err5:
270 nft_bitwise_module_exit();
271err4:
272 nft_lookup_module_exit();
273err3:
274 nft_cmp_module_exit();
275err2:
276 nft_immediate_module_exit();
277err1:
278 return err;
279}
280
281void nf_tables_core_module_exit(void)
282{
283 nft_dynset_module_exit();
284 nft_payload_module_exit();
285 nft_byteorder_module_exit();
286 nft_bitwise_module_exit();
287 nft_lookup_module_exit();
288 nft_cmp_module_exit();
289 nft_immediate_module_exit();
290}
291
