1 /* 2 * net/ipv6/fib6_rules.c IPv6 Routing Policy Rules 3 * 4 * Copyright (C)2003-2006 Helsinki University of Technology 5 * Copyright (C)2003-2006 USAGI/WIDE Project 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License as 9 * published by the Free Software Foundation, version 2. 10 * 11 * Authors 12 * Thomas Graf <tgraf@suug.ch> 13 * Ville Nuorvala <vnuorval@tcs.hut.fi> 14 */ 15 16 #include <linux/netdevice.h> 17 18 #include <net/fib_rules.h> 19 #include <net/ipv6.h> 20 #include <net/ip6_route.h> 21 #include <net/netlink.h> 22 23 struct fib6_rule 24 { 25 struct fib_rule common; 26 struct rt6key src; 27 struct rt6key dst; 28 u8 tclass; 29 }; 30 31 static struct fib_rules_ops fib6_rules_ops; 32 33 static struct fib6_rule main_rule = { 34 .common = { 35 .refcnt = ATOMIC_INIT(2), 36 .pref = 0x7FFE, 37 .action = FR_ACT_TO_TBL, 38 .table = RT6_TABLE_MAIN, 39 }, 40 }; 41 42 static struct fib6_rule local_rule = { 43 .common = { 44 .refcnt = ATOMIC_INIT(2), 45 .pref = 0, 46 .action = FR_ACT_TO_TBL, 47 .table = RT6_TABLE_LOCAL, 48 .flags = FIB_RULE_PERMANENT, 49 }, 50 }; 51 52 static LIST_HEAD(fib6_rules); 53 54 struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags, 55 pol_lookup_t lookup) 56 { 57 struct fib_lookup_arg arg = { 58 .lookup_ptr = lookup, 59 }; 60 61 fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg); 62 if (arg.rule) 63 fib_rule_put(arg.rule); 64 65 if (arg.result) 66 return arg.result; 67 68 dst_hold(&ip6_null_entry.u.dst); 69 return &ip6_null_entry.u.dst; 70 } 71 72 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, 73 int flags, struct fib_lookup_arg *arg) 74 { 75 struct rt6_info *rt = NULL; 76 struct fib6_table *table; 77 pol_lookup_t lookup = arg->lookup_ptr; 78 79 switch (rule->action) { 80 case FR_ACT_TO_TBL: 81 break; 82 case FR_ACT_UNREACHABLE: 83 rt = &ip6_null_entry; 84 goto discard_pkt; 85 default: 86 case FR_ACT_BLACKHOLE: 87 rt = &ip6_blk_hole_entry; 88 goto discard_pkt; 89 case FR_ACT_PROHIBIT: 90 rt = &ip6_prohibit_entry; 91 goto discard_pkt; 92 } 93 94 table = fib6_get_table(rule->table); 95 if (table) 96 rt = lookup(table, flp, flags); 97 98 if (rt != &ip6_null_entry) 99 goto out; 100 dst_release(&rt->u.dst); 101 rt = NULL; 102 goto out; 103 104 discard_pkt: 105 dst_hold(&rt->u.dst); 106 out: 107 arg->result = rt; 108 return rt == NULL ? -EAGAIN : 0; 109 } 110 111 112 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) 113 { 114 struct fib6_rule *r = (struct fib6_rule *) rule; 115 116 if (r->dst.plen && 117 !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen)) 118 return 0; 119 120 if (r->src.plen) { 121 if (!(flags & RT6_LOOKUP_F_HAS_SADDR) || 122 !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen)) 123 return 0; 124 } 125 126 if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff)) 127 return 0; 128 129 return 1; 130 } 131 132 static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = { 133 FRA_GENERIC_POLICY, 134 [FRA_SRC] = { .len = sizeof(struct in6_addr) }, 135 [FRA_DST] = { .len = sizeof(struct in6_addr) }, 136 }; 137 138 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb, 139 struct nlmsghdr *nlh, struct fib_rule_hdr *frh, 140 struct nlattr **tb) 141 { 142 int err = -EINVAL; 143 struct fib6_rule *rule6 = (struct fib6_rule *) rule; 144 145 if (frh->src_len > 128 || frh->dst_len > 128) 146 goto errout; 147 148 if (rule->action == FR_ACT_TO_TBL) { 149 if (rule->table == RT6_TABLE_UNSPEC) 150 goto errout; 151 152 if (fib6_new_table(rule->table) == NULL) { 153 err = -ENOBUFS; 154 goto errout; 155 } 156 } 157 158 if (tb[FRA_SRC]) 159 nla_memcpy(&rule6->src.addr, tb[FRA_SRC], 160 sizeof(struct in6_addr)); 161 162 if (tb[FRA_DST]) 163 nla_memcpy(&rule6->dst.addr, tb[FRA_DST], 164 sizeof(struct in6_addr)); 165 166 rule6->src.plen = frh->src_len; 167 rule6->dst.plen = frh->dst_len; 168 rule6->tclass = frh->tos; 169 170 err = 0; 171 errout: 172 return err; 173 } 174 175 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, 176 struct nlattr **tb) 177 { 178 struct fib6_rule *rule6 = (struct fib6_rule *) rule; 179 180 if (frh->src_len && (rule6->src.plen != frh->src_len)) 181 return 0; 182 183 if (frh->dst_len && (rule6->dst.plen != frh->dst_len)) 184 return 0; 185 186 if (frh->tos && (rule6->tclass != frh->tos)) 187 return 0; 188 189 if (tb[FRA_SRC] && 190 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr))) 191 return 0; 192 193 if (tb[FRA_DST] && 194 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr))) 195 return 0; 196 197 return 1; 198 } 199 200 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb, 201 struct nlmsghdr *nlh, struct fib_rule_hdr *frh) 202 { 203 struct fib6_rule *rule6 = (struct fib6_rule *) rule; 204 205 frh->family = AF_INET6; 206 frh->dst_len = rule6->dst.plen; 207 frh->src_len = rule6->src.plen; 208 frh->tos = rule6->tclass; 209 210 if (rule6->dst.plen) 211 NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr), 212 &rule6->dst.addr); 213 214 if (rule6->src.plen) 215 NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr), 216 &rule6->src.addr); 217 218 return 0; 219 220 nla_put_failure: 221 return -ENOBUFS; 222 } 223 224 int fib6_rules_dump(struct sk_buff *skb, struct netlink_callback *cb) 225 { 226 return fib_rules_dump(skb, cb, AF_INET6); 227 } 228 229 static u32 fib6_rule_default_pref(void) 230 { 231 return 0x3FFF; 232 } 233 234 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule) 235 { 236 return nla_total_size(16) /* dst */ 237 + nla_total_size(16); /* src */ 238 } 239 240 static struct fib_rules_ops fib6_rules_ops = { 241 .family = AF_INET6, 242 .rule_size = sizeof(struct fib6_rule), 243 .action = fib6_rule_action, 244 .match = fib6_rule_match, 245 .configure = fib6_rule_configure, 246 .compare = fib6_rule_compare, 247 .fill = fib6_rule_fill, 248 .default_pref = fib6_rule_default_pref, 249 .nlmsg_payload = fib6_rule_nlmsg_payload, 250 .nlgroup = RTNLGRP_IPV6_RULE, 251 .policy = fib6_rule_policy, 252 .rules_list = &fib6_rules, 253 .owner = THIS_MODULE, 254 }; 255 256 void __init fib6_rules_init(void) 257 { 258 list_add_tail(&local_rule.common.list, &fib6_rules); 259 list_add_tail(&main_rule.common.list, &fib6_rules); 260 261 fib_rules_register(&fib6_rules_ops); 262 } 263 264 void fib6_rules_cleanup(void) 265 { 266 fib_rules_unregister(&fib6_rules_ops); 267 } 268