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/netfilter/nfnetlink.h> 20 #include <linux/netfilter/nf_tables.h> 21 #include <net/netfilter/nf_tables_core.h> 22 #include <net/netfilter/nf_tables.h> 23 #include <net/netfilter/nf_log.h> 24 25 enum nft_trace { 26 NFT_TRACE_RULE, 27 NFT_TRACE_RETURN, 28 NFT_TRACE_POLICY, 29 }; 30 31 static const char *const comments[] = { 32 [NFT_TRACE_RULE] = "rule", 33 [NFT_TRACE_RETURN] = "return", 34 [NFT_TRACE_POLICY] = "policy", 35 }; 36 37 static struct nf_loginfo trace_loginfo = { 38 .type = NF_LOG_TYPE_LOG, 39 .u = { 40 .log = { 41 .level = LOGLEVEL_WARNING, 42 .logflags = NF_LOG_MASK, 43 }, 44 }, 45 }; 46 47 static void __nft_trace_packet(const struct nft_pktinfo *pkt, 48 const struct nft_chain *chain, 49 int rulenum, enum nft_trace type) 50 { 51 nf_log_trace(pkt->net, pkt->pf, pkt->hook, pkt->skb, pkt->in, 52 pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ", 53 chain->table->name, chain->name, comments[type], 54 rulenum); 55 } 56 57 static inline void nft_trace_packet(const struct nft_pktinfo *pkt, 58 const struct nft_chain *chain, 59 int rulenum, enum nft_trace type) 60 { 61 if (unlikely(pkt->skb->nf_trace)) 62 __nft_trace_packet(pkt, chain, rulenum, type); 63 } 64 65 static void nft_cmp_fast_eval(const struct nft_expr *expr, 66 struct nft_regs *regs) 67 { 68 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 69 u32 mask = nft_cmp_fast_mask(priv->len); 70 71 if ((regs->data[priv->sreg] & mask) == priv->data) 72 return; 73 regs->verdict.code = NFT_BREAK; 74 } 75 76 static bool nft_payload_fast_eval(const struct nft_expr *expr, 77 struct nft_regs *regs, 78 const struct nft_pktinfo *pkt) 79 { 80 const struct nft_payload *priv = nft_expr_priv(expr); 81 const struct sk_buff *skb = pkt->skb; 82 u32 *dest = ®s->data[priv->dreg]; 83 unsigned char *ptr; 84 85 if (priv->base == NFT_PAYLOAD_NETWORK_HEADER) 86 ptr = skb_network_header(skb); 87 else 88 ptr = skb_network_header(skb) + pkt->xt.thoff; 89 90 ptr += priv->offset; 91 92 if (unlikely(ptr + priv->len >= skb_tail_pointer(skb))) 93 return false; 94 95 *dest = 0; 96 if (priv->len == 2) 97 *(u16 *)dest = *(u16 *)ptr; 98 else if (priv->len == 4) 99 *(u32 *)dest = *(u32 *)ptr; 100 else 101 *(u8 *)dest = *(u8 *)ptr; 102 return true; 103 } 104 105 struct nft_jumpstack { 106 const struct nft_chain *chain; 107 const struct nft_rule *rule; 108 int rulenum; 109 }; 110 111 unsigned int 112 nft_do_chain(struct nft_pktinfo *pkt, void *priv) 113 { 114 const struct nft_chain *chain = priv, *basechain = chain; 115 const struct net *net = pkt->net; 116 const struct nft_rule *rule; 117 const struct nft_expr *expr, *last; 118 struct nft_regs regs; 119 unsigned int stackptr = 0; 120 struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE]; 121 struct nft_stats *stats; 122 int rulenum; 123 unsigned int gencursor = nft_genmask_cur(net); 124 125 do_chain: 126 rulenum = 0; 127 rule = list_entry(&chain->rules, struct nft_rule, list); 128 next_rule: 129 regs.verdict.code = NFT_CONTINUE; 130 list_for_each_entry_continue_rcu(rule, &chain->rules, list) { 131 132 /* This rule is not active, skip. */ 133 if (unlikely(rule->genmask & (1 << gencursor))) 134 continue; 135 136 rulenum++; 137 138 nft_rule_for_each_expr(expr, last, rule) { 139 if (expr->ops == &nft_cmp_fast_ops) 140 nft_cmp_fast_eval(expr, ®s); 141 else if (expr->ops != &nft_payload_fast_ops || 142 !nft_payload_fast_eval(expr, ®s, pkt)) 143 expr->ops->eval(expr, ®s, pkt); 144 145 if (regs.verdict.code != NFT_CONTINUE) 146 break; 147 } 148 149 switch (regs.verdict.code) { 150 case NFT_BREAK: 151 regs.verdict.code = NFT_CONTINUE; 152 continue; 153 case NFT_CONTINUE: 154 nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE); 155 continue; 156 } 157 break; 158 } 159 160 switch (regs.verdict.code & NF_VERDICT_MASK) { 161 case NF_ACCEPT: 162 case NF_DROP: 163 case NF_QUEUE: 164 nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE); 165 return regs.verdict.code; 166 } 167 168 switch (regs.verdict.code) { 169 case NFT_JUMP: 170 BUG_ON(stackptr >= NFT_JUMP_STACK_SIZE); 171 jumpstack[stackptr].chain = chain; 172 jumpstack[stackptr].rule = rule; 173 jumpstack[stackptr].rulenum = rulenum; 174 stackptr++; 175 /* fall through */ 176 case NFT_GOTO: 177 nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE); 178 179 chain = regs.verdict.chain; 180 goto do_chain; 181 case NFT_CONTINUE: 182 rulenum++; 183 /* fall through */ 184 case NFT_RETURN: 185 nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RETURN); 186 break; 187 default: 188 WARN_ON(1); 189 } 190 191 if (stackptr > 0) { 192 stackptr--; 193 chain = jumpstack[stackptr].chain; 194 rule = jumpstack[stackptr].rule; 195 rulenum = jumpstack[stackptr].rulenum; 196 goto next_rule; 197 } 198 199 nft_trace_packet(pkt, basechain, -1, NFT_TRACE_POLICY); 200 201 rcu_read_lock_bh(); 202 stats = this_cpu_ptr(rcu_dereference(nft_base_chain(basechain)->stats)); 203 u64_stats_update_begin(&stats->syncp); 204 stats->pkts++; 205 stats->bytes += pkt->skb->len; 206 u64_stats_update_end(&stats->syncp); 207 rcu_read_unlock_bh(); 208 209 return nft_base_chain(basechain)->policy; 210 } 211 EXPORT_SYMBOL_GPL(nft_do_chain); 212 213 int __init nf_tables_core_module_init(void) 214 { 215 int err; 216 217 err = nft_immediate_module_init(); 218 if (err < 0) 219 goto err1; 220 221 err = nft_cmp_module_init(); 222 if (err < 0) 223 goto err2; 224 225 err = nft_lookup_module_init(); 226 if (err < 0) 227 goto err3; 228 229 err = nft_bitwise_module_init(); 230 if (err < 0) 231 goto err4; 232 233 err = nft_byteorder_module_init(); 234 if (err < 0) 235 goto err5; 236 237 err = nft_payload_module_init(); 238 if (err < 0) 239 goto err6; 240 241 err = nft_dynset_module_init(); 242 if (err < 0) 243 goto err7; 244 245 return 0; 246 247 err7: 248 nft_payload_module_exit(); 249 err6: 250 nft_byteorder_module_exit(); 251 err5: 252 nft_bitwise_module_exit(); 253 err4: 254 nft_lookup_module_exit(); 255 err3: 256 nft_cmp_module_exit(); 257 err2: 258 nft_immediate_module_exit(); 259 err1: 260 return err; 261 } 262 263 void nf_tables_core_module_exit(void) 264 { 265 nft_dynset_module_exit(); 266 nft_payload_module_exit(); 267 nft_byteorder_module_exit(); 268 nft_bitwise_module_exit(); 269 nft_lookup_module_exit(); 270 nft_cmp_module_exit(); 271 nft_immediate_module_exit(); 272 } 273