1 /** 2 * \file 3 * This file implements the ipset module. It can handle packets by putting 4 * the A and AAAA addresses that are configured in unbound.conf as type 5 * ipset (local-zone statements) into a firewall rule IPSet. For firewall 6 * blacklist and whitelist usage. 7 */ 8 #include "config.h" 9 #include "ipset/ipset.h" 10 #include "util/regional.h" 11 #include "util/net_help.h" 12 #include "util/config_file.h" 13 14 #include "services/cache/dns.h" 15 16 #include "sldns/sbuffer.h" 17 #include "sldns/wire2str.h" 18 #include "sldns/parseutil.h" 19 20 #include <libmnl/libmnl.h> 21 #include <linux/netfilter/nfnetlink.h> 22 #include <linux/netfilter/ipset/ip_set.h> 23 24 #define BUFF_LEN 256 25 26 /** 27 * Return an error 28 * @param qstate: our query state 29 * @param id: module id 30 * @param rcode: error code (DNS errcode). 31 * @return: 0 for use by caller, to make notation easy, like: 32 * return error_response(..). 33 */ 34 static int error_response(struct module_qstate* qstate, int id, int rcode) { 35 verbose(VERB_QUERY, "return error response %s", 36 sldns_lookup_by_id(sldns_rcodes, rcode)? 37 sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??"); 38 qstate->return_rcode = rcode; 39 qstate->return_msg = NULL; 40 qstate->ext_state[id] = module_finished; 41 return 0; 42 } 43 44 static struct mnl_socket * open_mnl_socket() { 45 struct mnl_socket *mnl; 46 47 mnl = mnl_socket_open(NETLINK_NETFILTER); 48 if (!mnl) { 49 log_err("ipset: could not open netfilter."); 50 return NULL; 51 } 52 53 if (mnl_socket_bind(mnl, 0, MNL_SOCKET_AUTOPID) < 0) { 54 mnl_socket_close(mnl); 55 log_err("ipset: could not bind netfilter."); 56 return NULL; 57 } 58 return mnl; 59 } 60 61 static int add_to_ipset(struct mnl_socket *mnl, const char *setname, const void *ipaddr, int af) { 62 struct nlmsghdr *nlh; 63 struct nfgenmsg *nfg; 64 struct nlattr *nested[2]; 65 static char buffer[BUFF_LEN]; 66 67 if (strlen(setname) >= IPSET_MAXNAMELEN) { 68 errno = ENAMETOOLONG; 69 return -1; 70 } 71 if (af != AF_INET && af != AF_INET6) { 72 errno = EAFNOSUPPORT; 73 return -1; 74 } 75 76 nlh = mnl_nlmsg_put_header(buffer); 77 nlh->nlmsg_type = IPSET_CMD_ADD | (NFNL_SUBSYS_IPSET << 8); 78 nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL; 79 80 nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg)); 81 nfg->nfgen_family = af; 82 nfg->version = NFNETLINK_V0; 83 nfg->res_id = htons(0); 84 85 mnl_attr_put_u8(nlh, IPSET_ATTR_PROTOCOL, IPSET_PROTOCOL); 86 mnl_attr_put(nlh, IPSET_ATTR_SETNAME, strlen(setname) + 1, setname); 87 nested[0] = mnl_attr_nest_start(nlh, IPSET_ATTR_DATA); 88 nested[1] = mnl_attr_nest_start(nlh, IPSET_ATTR_IP); 89 mnl_attr_put(nlh, (af == AF_INET ? IPSET_ATTR_IPADDR_IPV4 : IPSET_ATTR_IPADDR_IPV6) 90 | NLA_F_NET_BYTEORDER, (af == AF_INET ? sizeof(struct in_addr) : sizeof(struct in6_addr)), ipaddr); 91 mnl_attr_nest_end(nlh, nested[1]); 92 mnl_attr_nest_end(nlh, nested[0]); 93 94 if (mnl_socket_sendto(mnl, nlh, nlh->nlmsg_len) < 0) { 95 return -1; 96 } 97 return 0; 98 } 99 100 static void 101 ipset_add_rrset_data(struct ipset_env *ie, struct mnl_socket *mnl, 102 struct packed_rrset_data *d, const char* setname, int af, 103 const char* dname) 104 { 105 int ret; 106 size_t j, rr_len, rd_len; 107 uint8_t *rr_data; 108 109 /* to d->count, not d->rrsig_count, because we do not want to add the RRSIGs, only the addresses */ 110 for (j = 0; j < d->count; j++) { 111 rr_len = d->rr_len[j]; 112 rr_data = d->rr_data[j]; 113 114 rd_len = sldns_read_uint16(rr_data); 115 if(af == AF_INET && rd_len != INET_SIZE) 116 continue; 117 if(af == AF_INET6 && rd_len != INET6_SIZE) 118 continue; 119 if (rr_len - 2 >= rd_len) { 120 if(verbosity >= VERB_QUERY) { 121 char ip[128]; 122 if(inet_ntop(af, rr_data+2, ip, (socklen_t)sizeof(ip)) == 0) 123 snprintf(ip, sizeof(ip), "(inet_ntop_error)"); 124 verbose(VERB_QUERY, "ipset: add %s to %s for %s", ip, setname, dname); 125 } 126 ret = add_to_ipset(mnl, setname, rr_data + 2, af); 127 if (ret < 0) { 128 log_err("ipset: could not add %s into %s", dname, setname); 129 130 mnl_socket_close(mnl); 131 ie->mnl = NULL; 132 break; 133 } 134 } 135 } 136 } 137 138 static int 139 ipset_check_zones_for_rrset(struct module_env *env, struct ipset_env *ie, 140 struct mnl_socket *mnl, struct ub_packed_rrset_key *rrset, 141 const char *setname, int af) 142 { 143 static char dname[BUFF_LEN]; 144 const char *s; 145 int dlen, plen; 146 147 struct config_strlist *p; 148 struct packed_rrset_data *d; 149 150 dlen = sldns_wire2str_dname_buf(rrset->rk.dname, rrset->rk.dname_len, dname, BUFF_LEN); 151 if (dlen == 0) { 152 log_err("bad domain name"); 153 return -1; 154 } 155 if (dname[dlen - 1] == '.') { 156 dlen--; 157 } 158 159 for (p = env->cfg->local_zones_ipset; p; p = p->next) { 160 plen = strlen(p->str); 161 162 if (dlen >= plen) { 163 s = dname + (dlen - plen); 164 165 if (strncasecmp(p->str, s, plen) == 0) { 166 d = (struct packed_rrset_data*)rrset->entry.data; 167 ipset_add_rrset_data(ie, mnl, d, setname, 168 af, dname); 169 break; 170 } 171 } 172 } 173 return 0; 174 } 175 176 static int ipset_update(struct module_env *env, struct dns_msg *return_msg, struct ipset_env *ie) { 177 struct mnl_socket *mnl; 178 179 size_t i; 180 181 const char *setname; 182 183 struct ub_packed_rrset_key *rrset; 184 185 int af; 186 187 188 mnl = (struct mnl_socket *)ie->mnl; 189 if (!mnl) { 190 // retry to create mnl socket 191 mnl = open_mnl_socket(); 192 if (!mnl) { 193 return -1; 194 } 195 196 ie->mnl = mnl; 197 } 198 199 for (i = 0; i < return_msg->rep->rrset_count; ++i) { 200 setname = NULL; 201 202 rrset = return_msg->rep->rrsets[i]; 203 204 if (rrset->rk.type == htons(LDNS_RR_TYPE_A)) { 205 af = AF_INET; 206 if ((ie->v4_enabled == 1)) { 207 setname = ie->name_v4; 208 } 209 } else { 210 af = AF_INET6; 211 if ((ie->v6_enabled == 1)) { 212 setname = ie->name_v6; 213 } 214 } 215 216 if (setname) { 217 if(ipset_check_zones_for_rrset(env, ie, mnl, rrset, 218 setname, af) == -1) 219 return -1; 220 } 221 } 222 223 return 0; 224 } 225 226 int ipset_init(struct module_env* env, int id) { 227 struct ipset_env *ipset_env; 228 229 ipset_env = (struct ipset_env *)calloc(1, sizeof(struct ipset_env)); 230 if (!ipset_env) { 231 log_err("malloc failure"); 232 return 0; 233 } 234 235 env->modinfo[id] = (void *)ipset_env; 236 237 ipset_env->mnl = NULL; 238 239 ipset_env->name_v4 = env->cfg->ipset_name_v4; 240 ipset_env->name_v6 = env->cfg->ipset_name_v6; 241 242 ipset_env->v4_enabled = !ipset_env->name_v4 || (strlen(ipset_env->name_v4) == 0) ? 0 : 1; 243 ipset_env->v6_enabled = !ipset_env->name_v6 || (strlen(ipset_env->name_v6) == 0) ? 0 : 1; 244 245 if ((ipset_env->v4_enabled < 1) && (ipset_env->v6_enabled < 1)) { 246 log_err("ipset: set name no configuration?"); 247 return 0; 248 } 249 250 return 1; 251 } 252 253 void ipset_deinit(struct module_env *env, int id) { 254 struct mnl_socket *mnl; 255 struct ipset_env *ipset_env; 256 257 if (!env || !env->modinfo[id]) { 258 return; 259 } 260 261 ipset_env = (struct ipset_env *)env->modinfo[id]; 262 263 mnl = (struct mnl_socket *)ipset_env->mnl; 264 if (mnl) { 265 mnl_socket_close(mnl); 266 ipset_env->mnl = NULL; 267 } 268 269 free(ipset_env); 270 env->modinfo[id] = NULL; 271 } 272 273 static int ipset_new(struct module_qstate* qstate, int id) { 274 struct ipset_qstate *iq = (struct ipset_qstate *)regional_alloc( 275 qstate->region, sizeof(struct ipset_qstate)); 276 qstate->minfo[id] = iq; 277 if (!iq) { 278 return 0; 279 } 280 281 memset(iq, 0, sizeof(*iq)); 282 /* initialise it */ 283 /* TODO */ 284 285 return 1; 286 } 287 288 void ipset_operate(struct module_qstate *qstate, enum module_ev event, int id, 289 struct outbound_entry *outbound) { 290 struct ipset_env *ie = (struct ipset_env *)qstate->env->modinfo[id]; 291 struct ipset_qstate *iq = (struct ipset_qstate *)qstate->minfo[id]; 292 verbose(VERB_QUERY, "ipset[module %d] operate: extstate:%s event:%s", 293 id, strextstate(qstate->ext_state[id]), strmodulevent(event)); 294 if (iq) { 295 log_query_info(VERB_QUERY, "ipset operate: query", &qstate->qinfo); 296 } 297 298 /* perform ipset state machine */ 299 if ((event == module_event_new || event == module_event_pass) && !iq) { 300 if (!ipset_new(qstate, id)) { 301 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 302 return; 303 } 304 iq = (struct ipset_qstate*)qstate->minfo[id]; 305 } 306 307 if (iq && (event == module_event_pass || event == module_event_new)) { 308 qstate->ext_state[id] = module_wait_module; 309 return; 310 } 311 312 if (iq && (event == module_event_moddone)) { 313 if (qstate->return_msg && qstate->return_msg->rep) { 314 ipset_update(qstate->env, qstate->return_msg, ie); 315 } 316 qstate->ext_state[id] = module_finished; 317 return; 318 } 319 320 if (iq && outbound) { 321 /* ipset does not need to process responses at this time 322 * ignore it. 323 ipset_process_response(qstate, iq, ie, id, outbound, event); 324 */ 325 return; 326 } 327 328 if (event == module_event_error) { 329 verbose(VERB_ALGO, "got called with event error, giving up"); 330 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 331 return; 332 } 333 334 if (!iq && (event == module_event_moddone)) { 335 /* during priming, module done but we never started */ 336 qstate->ext_state[id] = module_finished; 337 return; 338 } 339 340 log_err("bad event for ipset"); 341 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 342 } 343 344 void ipset_inform_super(struct module_qstate *ATTR_UNUSED(qstate), 345 int ATTR_UNUSED(id), struct module_qstate *ATTR_UNUSED(super)) { 346 /* ipset does not use subordinate requests at this time */ 347 verbose(VERB_ALGO, "ipset inform_super was called"); 348 } 349 350 void ipset_clear(struct module_qstate *qstate, int id) { 351 struct cachedb_qstate *iq; 352 if (!qstate) { 353 return; 354 } 355 iq = (struct cachedb_qstate *)qstate->minfo[id]; 356 if (iq) { 357 /* free contents of iq */ 358 /* TODO */ 359 } 360 qstate->minfo[id] = NULL; 361 } 362 363 size_t ipset_get_mem(struct module_env *env, int id) { 364 struct ipset_env *ie = (struct ipset_env *)env->modinfo[id]; 365 if (!ie) { 366 return 0; 367 } 368 return sizeof(*ie); 369 } 370 371 /** 372 * The ipset function block 373 */ 374 static struct module_func_block ipset_block = { 375 "ipset", 376 &ipset_init, &ipset_deinit, &ipset_operate, 377 &ipset_inform_super, &ipset_clear, &ipset_get_mem 378 }; 379 380 struct module_func_block * ipset_get_funcblock(void) { 381 return &ipset_block; 382 } 383 384