/* * iterator/iter_hints.c - iterative resolver module stub and root hints. * * Copyright (c) 2007, NLnet Labs. All rights reserved. * * This software is open source. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the NLNET LABS nor the names of its contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** * \file * * This file contains functions to assist the iterator module. * Keep track of stub and root hints, and read those from config. */ #include "config.h" #include "iterator/iter_hints.h" #include "iterator/iter_delegpt.h" #include "util/log.h" #include "util/config_file.h" #include "util/net_help.h" #include "util/data/dname.h" #include "sldns/rrdef.h" #include "sldns/str2wire.h" #include "sldns/wire2str.h" struct iter_hints* hints_create(void) { struct iter_hints* hints = (struct iter_hints*)calloc(1, sizeof(struct iter_hints)); if(!hints) return NULL; return hints; } static void hints_stub_free(struct iter_hints_stub* s) { if(!s) return; delegpt_free_mlc(s->dp); free(s); } static void delhintnode(rbnode_t* n, void* ATTR_UNUSED(arg)) { struct iter_hints_stub* node = (struct iter_hints_stub*)n; hints_stub_free(node); } static void hints_del_tree(struct iter_hints* hints) { traverse_postorder(&hints->tree, &delhintnode, NULL); } void hints_delete(struct iter_hints* hints) { if(!hints) return; hints_del_tree(hints); free(hints); } /** add hint to delegation hints */ static int ah(struct delegpt* dp, const char* sv, const char* ip) { struct sockaddr_storage addr; socklen_t addrlen; size_t dname_len; uint8_t* dname = sldns_str2wire_dname(sv, &dname_len); if(!dname) { log_err("could not parse %s", sv); return 0; } if(!delegpt_add_ns_mlc(dp, dname, 0) || !extstrtoaddr(ip, &addr, &addrlen) || !delegpt_add_target_mlc(dp, dname, dname_len, &addr, addrlen, 0, 0)) { free(dname); return 0; } free(dname); return 1; } /** obtain compiletime provided root hints */ static struct delegpt* compile_time_root_prime(int do_ip4, int do_ip6) { /* from: ; This file is made available by InterNIC ; under anonymous FTP as ; file /domain/named.cache ; on server FTP.INTERNIC.NET ; -OR- RS.INTERNIC.NET ; ; related version of root zone: changes-on-20120103 */ struct delegpt* dp = delegpt_create_mlc((uint8_t*)"\000"); if(!dp) return NULL; dp->has_parent_side_NS = 1; if(do_ip4) { if(!ah(dp, "A.ROOT-SERVERS.NET.", "198.41.0.4")) goto failed; if(!ah(dp, "B.ROOT-SERVERS.NET.", "192.228.79.201")) goto failed; if(!ah(dp, "C.ROOT-SERVERS.NET.", "192.33.4.12")) goto failed; if(!ah(dp, "D.ROOT-SERVERS.NET.", "199.7.91.13")) goto failed; if(!ah(dp, "E.ROOT-SERVERS.NET.", "192.203.230.10")) goto failed; if(!ah(dp, "F.ROOT-SERVERS.NET.", "192.5.5.241")) goto failed; if(!ah(dp, "G.ROOT-SERVERS.NET.", "192.112.36.4")) goto failed; if(!ah(dp, "H.ROOT-SERVERS.NET.", "198.97.190.53")) goto failed; if(!ah(dp, "I.ROOT-SERVERS.NET.", "192.36.148.17")) goto failed; if(!ah(dp, "J.ROOT-SERVERS.NET.", "192.58.128.30")) goto failed; if(!ah(dp, "K.ROOT-SERVERS.NET.", "193.0.14.129")) goto failed; if(!ah(dp, "L.ROOT-SERVERS.NET.", "199.7.83.42")) goto failed; if(!ah(dp, "M.ROOT-SERVERS.NET.", "202.12.27.33")) goto failed; } if(do_ip6) { if(!ah(dp, "A.ROOT-SERVERS.NET.", "2001:503:ba3e::2:30")) goto failed; if(!ah(dp, "B.ROOT-SERVERS.NET.", "2001:500:84::b")) goto failed; if(!ah(dp, "C.ROOT-SERVERS.NET.", "2001:500:2::c")) goto failed; if(!ah(dp, "D.ROOT-SERVERS.NET.", "2001:500:2d::d")) goto failed; if(!ah(dp, "F.ROOT-SERVERS.NET.", "2001:500:2f::f")) goto failed; if(!ah(dp, "H.ROOT-SERVERS.NET.", "2001:500:1::53")) goto failed; if(!ah(dp, "I.ROOT-SERVERS.NET.", "2001:7fe::53")) goto failed; if(!ah(dp, "J.ROOT-SERVERS.NET.", "2001:503:c27::2:30")) goto failed; if(!ah(dp, "K.ROOT-SERVERS.NET.", "2001:7fd::1")) goto failed; if(!ah(dp, "L.ROOT-SERVERS.NET.", "2001:500:9f::42")) goto failed; if(!ah(dp, "M.ROOT-SERVERS.NET.", "2001:dc3::35")) goto failed; } return dp; failed: delegpt_free_mlc(dp); return 0; } /** insert new hint info into hint structure */ static int hints_insert(struct iter_hints* hints, uint16_t c, struct delegpt* dp, int noprime) { struct iter_hints_stub* node = (struct iter_hints_stub*)malloc( sizeof(struct iter_hints_stub)); if(!node) { delegpt_free_mlc(dp); return 0; } node->dp = dp; node->noprime = (uint8_t)noprime; if(!name_tree_insert(&hints->tree, &node->node, dp->name, dp->namelen, dp->namelabs, c)) { char buf[257]; dname_str(dp->name, buf); log_err("second hints for zone %s ignored.", buf); delegpt_free_mlc(dp); free(node); } return 1; } /** set stub name */ static struct delegpt* read_stubs_name(struct config_stub* s) { struct delegpt* dp; size_t dname_len; uint8_t* dname; if(!s->name) { log_err("stub zone without a name"); return NULL; } dname = sldns_str2wire_dname(s->name, &dname_len); if(!dname) { log_err("cannot parse stub zone name %s", s->name); return NULL; } if(!(dp=delegpt_create_mlc(dname))) { free(dname); log_err("out of memory"); return NULL; } free(dname); return dp; } /** set stub host names */ static int read_stubs_host(struct config_stub* s, struct delegpt* dp) { struct config_strlist* p; size_t dname_len; uint8_t* dname; for(p = s->hosts; p; p = p->next) { log_assert(p->str); dname = sldns_str2wire_dname(p->str, &dname_len); if(!dname) { log_err("cannot parse stub %s nameserver name: '%s'", s->name, p->str); return 0; } if(!delegpt_add_ns_mlc(dp, dname, 0)) { free(dname); log_err("out of memory"); return 0; } free(dname); } return 1; } /** set stub server addresses */ static int read_stubs_addr(struct config_stub* s, struct delegpt* dp) { struct config_strlist* p; struct sockaddr_storage addr; socklen_t addrlen; for(p = s->addrs; p; p = p->next) { log_assert(p->str); if(!extstrtoaddr(p->str, &addr, &addrlen)) { log_err("cannot parse stub %s ip address: '%s'", s->name, p->str); return 0; } if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) { log_err("out of memory"); return 0; } } return 1; } /** read stubs config */ static int read_stubs(struct iter_hints* hints, struct config_file* cfg) { struct config_stub* s; struct delegpt* dp; for(s = cfg->stubs; s; s = s->next) { if(!(dp=read_stubs_name(s))) return 0; if(!read_stubs_host(s, dp) || !read_stubs_addr(s, dp)) { delegpt_free_mlc(dp); return 0; } /* the flag is turned off for 'stub-first' so that the * last resort will ask for parent-side NS record and thus * fallback to the internet name servers on a failure */ dp->has_parent_side_NS = (uint8_t)!s->isfirst; delegpt_log(VERB_QUERY, dp); if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, !s->isprime)) return 0; } return 1; } /** read root hints from file */ static int read_root_hints(struct iter_hints* hints, char* fname) { struct sldns_file_parse_state pstate; struct delegpt* dp; uint8_t rr[LDNS_RR_BUF_SIZE]; size_t rr_len, dname_len; int status; uint16_t c = LDNS_RR_CLASS_IN; FILE* f = fopen(fname, "r"); if(!f) { log_err("could not read root hints %s: %s", fname, strerror(errno)); return 0; } dp = delegpt_create_mlc(NULL); if(!dp) { log_err("out of memory reading root hints"); fclose(f); return 0; } verbose(VERB_QUERY, "Reading root hints from %s", fname); memset(&pstate, 0, sizeof(pstate)); pstate.lineno = 1; dp->has_parent_side_NS = 1; while(!feof(f)) { rr_len = sizeof(rr); dname_len = 0; status = sldns_fp2wire_rr_buf(f, rr, &rr_len, &dname_len, &pstate); if(status != 0) { log_err("reading root hints %s %d:%d: %s", fname, pstate.lineno, LDNS_WIREPARSE_OFFSET(status), sldns_get_errorstr_parse(status)); goto stop_read; } if(rr_len == 0) continue; /* EMPTY line, TTL or ORIGIN */ if(sldns_wirerr_get_type(rr, rr_len, dname_len) == LDNS_RR_TYPE_NS) { if(!delegpt_add_ns_mlc(dp, sldns_wirerr_get_rdata(rr, rr_len, dname_len), 0)) { log_err("out of memory reading root hints"); goto stop_read; } c = sldns_wirerr_get_class(rr, rr_len, dname_len); if(!dp->name) { if(!delegpt_set_name_mlc(dp, rr)) { log_err("out of memory."); goto stop_read; } } } else if(sldns_wirerr_get_type(rr, rr_len, dname_len) == LDNS_RR_TYPE_A && sldns_wirerr_get_rdatalen(rr, rr_len, dname_len) == INET_SIZE) { struct sockaddr_in sa; socklen_t len = (socklen_t)sizeof(sa); memset(&sa, 0, len); sa.sin_family = AF_INET; sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); memmove(&sa.sin_addr, sldns_wirerr_get_rdata(rr, rr_len, dname_len), INET_SIZE); if(!delegpt_add_target_mlc(dp, rr, dname_len, (struct sockaddr_storage*)&sa, len, 0, 0)) { log_err("out of memory reading root hints"); goto stop_read; } } else if(sldns_wirerr_get_type(rr, rr_len, dname_len) == LDNS_RR_TYPE_AAAA && sldns_wirerr_get_rdatalen(rr, rr_len, dname_len) == INET6_SIZE) { struct sockaddr_in6 sa; socklen_t len = (socklen_t)sizeof(sa); memset(&sa, 0, len); sa.sin6_family = AF_INET6; sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); memmove(&sa.sin6_addr, sldns_wirerr_get_rdata(rr, rr_len, dname_len), INET6_SIZE); if(!delegpt_add_target_mlc(dp, rr, dname_len, (struct sockaddr_storage*)&sa, len, 0, 0)) { log_err("out of memory reading root hints"); goto stop_read; } } else { char buf[17]; sldns_wire2str_type_buf(sldns_wirerr_get_type(rr, rr_len, dname_len), buf, sizeof(buf)); log_warn("root hints %s:%d skipping type %s", fname, pstate.lineno, buf); } } fclose(f); if(!dp->name) { log_warn("root hints %s: no NS content", fname); delegpt_free_mlc(dp); return 1; } if(!hints_insert(hints, c, dp, 0)) { return 0; } delegpt_log(VERB_QUERY, dp); return 1; stop_read: delegpt_free_mlc(dp); fclose(f); return 0; } /** read root hints list */ static int read_root_hints_list(struct iter_hints* hints, struct config_file* cfg) { struct config_strlist* p; for(p = cfg->root_hints; p; p = p->next) { log_assert(p->str); if(p->str && p->str[0]) { char* f = p->str; if(cfg->chrootdir && cfg->chrootdir[0] && strncmp(p->str, cfg->chrootdir, strlen(cfg->chrootdir)) == 0) f += strlen(cfg->chrootdir); if(!read_root_hints(hints, f)) return 0; } } return 1; } int hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg) { hints_del_tree(hints); name_tree_init(&hints->tree); /* read root hints */ if(!read_root_hints_list(hints, cfg)) return 0; /* read stub hints */ if(!read_stubs(hints, cfg)) return 0; /* use fallback compiletime root hints */ if(!hints_lookup_root(hints, LDNS_RR_CLASS_IN)) { struct delegpt* dp = compile_time_root_prime(cfg->do_ip4, cfg->do_ip6); verbose(VERB_ALGO, "no config, using builtin root hints."); if(!dp) return 0; if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, 0)) return 0; } name_tree_init_parents(&hints->tree); return 1; } struct delegpt* hints_lookup_root(struct iter_hints* hints, uint16_t qclass) { uint8_t rootlab = 0; struct iter_hints_stub *stub; stub = (struct iter_hints_stub*)name_tree_find(&hints->tree, &rootlab, 1, 1, qclass); if(!stub) return NULL; return stub->dp; } struct iter_hints_stub* hints_lookup_stub(struct iter_hints* hints, uint8_t* qname, uint16_t qclass, struct delegpt* cache_dp) { size_t len; int labs; struct iter_hints_stub *r; /* first lookup the stub */ labs = dname_count_size_labels(qname, &len); r = (struct iter_hints_stub*)name_tree_lookup(&hints->tree, qname, len, labs, qclass); if(!r) return NULL; /* If there is no cache (root prime situation) */ if(cache_dp == NULL) { if(r->dp->namelabs != 1) return r; /* no cache dp, use any non-root stub */ return NULL; } /* * If the stub is same as the delegation we got * And has noprime set, we need to 'prime' to use this stub instead. */ if(r->noprime && query_dname_compare(cache_dp->name, r->dp->name)==0) return r; /* use this stub instead of cached dp */ /* * If our cached delegation point is above the hint, we need to prime. */ if(dname_strict_subdomain(r->dp->name, r->dp->namelabs, cache_dp->name, cache_dp->namelabs)) return r; /* need to prime this stub */ return NULL; } int hints_next_root(struct iter_hints* hints, uint16_t* qclass) { return name_tree_next_root(&hints->tree, qclass); } size_t hints_get_mem(struct iter_hints* hints) { size_t s; struct iter_hints_stub* p; if(!hints) return 0; s = sizeof(*hints); RBTREE_FOR(p, struct iter_hints_stub*, &hints->tree) { s += sizeof(*p) + delegpt_get_mem(p->dp); } return s; } int hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp, int noprime) { struct iter_hints_stub *z; if((z=(struct iter_hints_stub*)name_tree_find(&hints->tree, dp->name, dp->namelen, dp->namelabs, c)) != NULL) { (void)rbtree_delete(&hints->tree, &z->node); hints_stub_free(z); } if(!hints_insert(hints, c, dp, noprime)) return 0; name_tree_init_parents(&hints->tree); return 1; } void hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm) { struct iter_hints_stub *z; size_t len; int labs = dname_count_size_labels(nm, &len); if(!(z=(struct iter_hints_stub*)name_tree_find(&hints->tree, nm, len, labs, c))) return; /* nothing to do */ (void)rbtree_delete(&hints->tree, &z->node); hints_stub_free(z); name_tree_init_parents(&hints->tree); }