1 /* 2 * Copyright (c) 2008 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 * Development of this code funded by Astaro AG (http://www.astaro.com/) 9 */ 10 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 26 static const char *const comments[__NFT_TRACETYPE_MAX] = { 27 [NFT_TRACETYPE_POLICY] = "policy", 28 [NFT_TRACETYPE_RETURN] = "return", 29 [NFT_TRACETYPE_RULE] = "rule", 30 }; 31 32 static 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 42 static 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 62 static 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 74 static 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 85 static 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 } 113 114 struct nft_jumpstack { 115 const struct nft_chain *chain; 116 const struct nft_rule *rule; 117 int rulenum; 118 }; 119 120 unsigned int 121 nft_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); 138 do_chain: 139 rulenum = 0; 140 rule = list_entry(&chain->rules, struct nft_rule, list); 141 next_rule: 142 regs.verdict.code = NFT_CONTINUE; 143 list_for_each_entry_continue_rcu(rule, &chain->rules, list) { 144 145 /* This rule is not active, skip. */ 146 if (unlikely(rule->genmask & 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 /* fall through */ 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 /* fall through */ 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 } 229 EXPORT_SYMBOL_GPL(nft_do_chain); 230 231 int __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; 264 265 err7: 266 nft_payload_module_exit(); 267 err6: 268 nft_byteorder_module_exit(); 269 err5: 270 nft_bitwise_module_exit(); 271 err4: 272 nft_lookup_module_exit(); 273 err3: 274 nft_cmp_module_exit(); 275 err2: 276 nft_immediate_module_exit(); 277 err1: 278 return err; 279 } 280 281 void 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