/* $OpenBSD: resolver.c,v 1.143 2021/02/07 13:35:41 florian Exp $ */ /* * Copyright (c) 2018 Florian Obser * Copyright (c) 2004, 2005 Claudio Jeker * Copyright (c) 2004 Esben Norby * Copyright (c) 2003, 2004 Henning Brauer * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "libunbound/config.h" #include "libunbound/libunbound/context.h" #include "libunbound/libunbound/libworker.h" #include "libunbound/libunbound/unbound.h" #include "libunbound/libunbound/unbound-event.h" #include "libunbound/services/cache/rrset.h" #include "libunbound/sldns/sbuffer.h" #include "libunbound/sldns/rrdef.h" #include "libunbound/sldns/pkthdr.h" #include "libunbound/sldns/wire2str.h" #include "libunbound/util/config_file.h" #include "libunbound/util/module.h" #include "libunbound/util/regional.h" #include "libunbound/util/storage/slabhash.h" #include "libunbound/validator/validator.h" #include "libunbound/validator/val_kcache.h" #include "libunbound/validator/val_neg.h" #include #include "log.h" #include "frontend.h" #include "unwind.h" #include "resolver.h" #define TLS_DEFAULT_CA_CERT_FILE "/etc/ssl/cert.pem" #define UB_LOG_VERBOSE 4 #define UB_LOG_BRIEF 0 /* maximum size of a libunbound forwarder definition: IP@PORT#AUTHNAME */ #define FWD_MAX (INET6_ADDRSTRLEN + NI_MAXHOST + 2 + 5) /* * The prefered resolver type can be this many ms slower than the next * best and still be picked */ #define PREF_RESOLVER_MEDIAN_SKEW 200 /* 200 ms */ #define NEXT_RES_MAX 2000 /* 2000 ms */ #define DOUBT_NXDOMAIN_SEC (5 * 60) /* 5 minutes */ #define RESOLVER_CHECK_SEC 1 #define RESOLVER_CHECK_MAXSEC 1024 /* ~17 minutes */ #define DECAY_PERIOD 60 #define DECAY_NOMINATOR 9 #define DECAY_DENOMINATOR 10 #define TRUST_ANCHOR_RETRY_INTERVAL 8640 #define TRUST_ANCHOR_QUERY_INTERVAL 43200 /* in libworker_event_done_cb() enum sec_status gets mapped to 0, 1 and 2 */ #define INSECURE 0 #define BOGUS 1 #define SECURE 2 #define WKA1_FOUND 1 #define WKA2_FOUND 2 struct uw_resolver { struct event check_ev; struct event free_ev; struct ub_ctx *ctx; void *asr_ctx; struct timeval check_tv; int ref_cnt; int stop; enum uw_resolver_state state; enum uw_resolver_type type; int check_running; int64_t median; int64_t histogram[nitems(histogram_limits)]; int64_t latest_histogram[nitems(histogram_limits)]; }; struct running_query { TAILQ_ENTRY(running_query) entry; struct query_imsg *query_imsg; struct event timer_ev; struct timespec tp; struct resolver_preference res_pref; int next_resolver; int running; }; TAILQ_HEAD(, running_query) running_queries; typedef void (*resolve_cb_t)(struct uw_resolver *, void *, int, void *, int, int, char *); struct resolver_cb_data { resolve_cb_t cb; void *data; struct uw_resolver *res; }; __dead void resolver_shutdown(void); void resolver_sig_handler(int sig, short, void *); void resolver_dispatch_frontend(int, short, void *); void resolver_dispatch_main(int, short, void *); int sort_resolver_types(struct resolver_preference *); void setup_query(struct query_imsg *); struct running_query *find_running_query(uint64_t); void try_resolver_timo(int, short, void *); int try_next_resolver(struct running_query *); int resolve(struct uw_resolver *, const char*, int, int, void*, resolve_cb_t); void resolve_done(struct uw_resolver *, void *, int, void *, int, int, char *); void ub_resolve_done(void *, int, void *, int, int, char *, int); void asr_resolve_done(struct asr_result *, void *); void new_resolver(enum uw_resolver_type, enum uw_resolver_state); struct uw_resolver *create_resolver(enum uw_resolver_type); void setup_unified_caches(void); void set_unified_cache(struct uw_resolver *); void free_resolver(struct uw_resolver *); void set_forwarders(struct uw_resolver *, struct uw_forwarder_head *, int); void resolver_check_timo(int, short, void *); void resolver_free_timo(int, short, void *); void check_resolver(struct uw_resolver *); void check_resolver_done(struct uw_resolver *, void *, int, void *, int, int, char *); void schedule_recheck_all_resolvers(void); int check_forwarders_changed(struct uw_forwarder_head *, struct uw_forwarder_head *); void replace_forwarders(struct uw_forwarder_head *, struct uw_forwarder_head *); void resolver_ref(struct uw_resolver *); void resolver_unref(struct uw_resolver *); int resolver_cmp(const void *, const void *); void restart_ub_resolvers(int); void show_status(pid_t); void show_autoconf(pid_t); void show_mem(pid_t); void send_resolver_info(struct uw_resolver *, pid_t); void send_detailed_resolver_info(struct uw_resolver *, pid_t); void trust_anchor_resolve(void); void trust_anchor_timo(int, short, void *); void trust_anchor_resolve_done(struct uw_resolver *, void *, int, void *, int, int, char *); void replace_autoconf_forwarders(struct imsg_rdns_proposal *); int force_tree_cmp(struct force_tree_entry *, struct force_tree_entry *); int find_force(struct force_tree *, char *, struct uw_resolver **); int64_t histogram_median(int64_t *); void decay_latest_histograms(int, short, void *); int running_query_cnt(void); int *resolvers_to_restart(struct uw_conf *, struct uw_conf *); const char *query_imsg2str(struct query_imsg *); char *gen_resolv_conf(void); void check_dns64(void); void check_dns64_done(struct asr_result *, void *); int dns64_prefixlen(const struct in6_addr *, const uint8_t *); void add_dns64_prefix(const struct in6_addr *, int, struct dns64_prefix *, int, int); struct uw_conf *resolver_conf; static struct imsgev *iev_frontend; static struct imsgev *iev_main; struct uw_forwarder_head autoconf_forwarder_list; struct uw_resolver *resolvers[UW_RES_NONE]; int enabled_resolvers[UW_RES_NONE]; struct timespec last_network_change; struct event trust_anchor_timer; struct event decay_timer; static struct trust_anchor_head trust_anchors, new_trust_anchors; struct event_base *ev_base; RB_GENERATE(force_tree, force_tree_entry, entry, force_tree_cmp) int val_id = -1; struct slabhash *unified_msg_cache; struct rrset_cache *unified_rrset_cache; struct key_cache *unified_key_cache; struct val_neg_cache *unified_neg_cache; int dns64_present; int available_afs = HAVE_IPV4 | HAVE_IPV6; static const char * const as112_zones[] = { /* RFC1918 */ "10.in-addr.arpa. transparent", "16.172.in-addr.arpa. transparent", "31.172.in-addr.arpa. transparent", "168.192.in-addr.arpa. transparent", /* RFC3330 */ "0.in-addr.arpa. transparent", "254.169.in-addr.arpa. transparent", "2.0.192.in-addr.arpa. transparent", "100.51.198.in-addr.arpa. transparent", "113.0.203.in-addr.arpa. transparent", "255.255.255.255.in-addr.arpa. transparent", /* RFC6598 */ "64.100.in-addr.arpa. transparent", "65.100.in-addr.arpa. transparent", "66.100.in-addr.arpa. transparent", "67.100.in-addr.arpa. transparent", "68.100.in-addr.arpa. transparent", "69.100.in-addr.arpa. transparent", "70.100.in-addr.arpa. transparent", "71.100.in-addr.arpa. transparent", "72.100.in-addr.arpa. transparent", "73.100.in-addr.arpa. transparent", "74.100.in-addr.arpa. transparent", "75.100.in-addr.arpa. transparent", "76.100.in-addr.arpa. transparent", "77.100.in-addr.arpa. transparent", "78.100.in-addr.arpa. transparent", "79.100.in-addr.arpa. transparent", "80.100.in-addr.arpa. transparent", "81.100.in-addr.arpa. transparent", "82.100.in-addr.arpa. transparent", "83.100.in-addr.arpa. transparent", "84.100.in-addr.arpa. transparent", "85.100.in-addr.arpa. transparent", "86.100.in-addr.arpa. transparent", "87.100.in-addr.arpa. transparent", "88.100.in-addr.arpa. transparent", "89.100.in-addr.arpa. transparent", "90.100.in-addr.arpa. transparent", "91.100.in-addr.arpa. transparent", "92.100.in-addr.arpa. transparent", "93.100.in-addr.arpa. transparent", "94.100.in-addr.arpa. transparent", "95.100.in-addr.arpa. transparent", "96.100.in-addr.arpa. transparent", "97.100.in-addr.arpa. transparent", "98.100.in-addr.arpa. transparent", "99.100.in-addr.arpa. transparent", "100.100.in-addr.arpa. transparent", "101.100.in-addr.arpa. transparent", "102.100.in-addr.arpa. transparent", "103.100.in-addr.arpa. transparent", "104.100.in-addr.arpa. transparent", "105.100.in-addr.arpa. transparent", "106.100.in-addr.arpa. transparent", "107.100.in-addr.arpa. transparent", "108.100.in-addr.arpa. transparent", "109.100.in-addr.arpa. transparent", "110.100.in-addr.arpa. transparent", "111.100.in-addr.arpa. transparent", "112.100.in-addr.arpa. transparent", "113.100.in-addr.arpa. transparent", "114.100.in-addr.arpa. transparent", "115.100.in-addr.arpa. transparent", "116.100.in-addr.arpa. transparent", "117.100.in-addr.arpa. transparent", "118.100.in-addr.arpa. transparent", "119.100.in-addr.arpa. transparent", "120.100.in-addr.arpa. transparent", "121.100.in-addr.arpa. transparent", "122.100.in-addr.arpa. transparent", "123.100.in-addr.arpa. transparent", "124.100.in-addr.arpa. transparent", "125.100.in-addr.arpa. transparent", "126.100.in-addr.arpa. transparent", "127.100.in-addr.arpa. transparent", /* RFC4291 */ "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0." "ip6.arpa. transparent", /* RFC4193 */ "D.F.ip6.arpa. transparent", /* RFC4291 */ "8.E.F.ip6.arpa. transparent", "9.E.F.ip6.arpa. transparent", "A.E.F.ip6.arpa. transparent", "B.E.F.ip6.arpa. transparent", /* RFC3849 */ "8.B.D.0.1.0.0.2.ip6.arpa. transparent" }; const char bogus_past[] = "validation failure <. NS IN>: signature " "expired"; const char bogus_future[] = "validation failure <. NS IN>: signature " "before inception date"; void resolver_sig_handler(int sig, short event, void *arg) { /* * Normal signal handler rules don't apply because libevent * decouples for us. */ switch (sig) { case SIGINT: case SIGTERM: resolver_shutdown(); default: fatalx("unexpected signal"); } } void resolver(int debug, int verbose) { struct event ev_sigint, ev_sigterm; struct passwd *pw; struct timeval tv = {DECAY_PERIOD, 0}; struct alloc_cache cache_alloc_test; resolver_conf = config_new_empty(); log_init(debug, LOG_DAEMON); log_setverbose(verbose); if ((pw = getpwnam(UNWIND_USER)) == NULL) fatal("getpwnam"); setproctitle("%s", "resolver"); log_procinit("resolver"); if (setgroups(1, &pw->pw_gid) || setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) fatal("can't drop privileges"); if (unveil(TLS_DEFAULT_CA_CERT_FILE, "r") == -1) fatal("unveil"); if (pledge("stdio inet dns rpath recvfd", NULL) == -1) fatal("pledge"); ev_base = event_init(); /* Setup signal handler(s). */ signal_set(&ev_sigint, SIGINT, resolver_sig_handler, NULL); signal_set(&ev_sigterm, SIGTERM, resolver_sig_handler, NULL); signal_add(&ev_sigint, NULL); signal_add(&ev_sigterm, NULL); signal(SIGPIPE, SIG_IGN); signal(SIGHUP, SIG_IGN); /* Setup pipe and event handler to the main process. */ if ((iev_main = malloc(sizeof(struct imsgev))) == NULL) fatal(NULL); imsg_init(&iev_main->ibuf, 3); iev_main->handler = resolver_dispatch_main; /* Setup event handlers. */ iev_main->events = EV_READ; event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events, iev_main->handler, iev_main); event_add(&iev_main->ev, NULL); evtimer_set(&trust_anchor_timer, trust_anchor_timo, NULL); evtimer_set(&decay_timer, decay_latest_histograms, NULL); evtimer_add(&decay_timer, &tv); clock_gettime(CLOCK_MONOTONIC, &last_network_change); alloc_init(&cache_alloc_test, NULL, 0); if (cache_alloc_test.max_reg_blocks != 10) fatalx("local libunbound/util/alloc.c diff lost"); alloc_clear(&cache_alloc_test); setup_unified_caches(); TAILQ_INIT(&autoconf_forwarder_list); TAILQ_INIT(&trust_anchors); TAILQ_INIT(&new_trust_anchors); TAILQ_INIT(&running_queries); event_dispatch(); resolver_shutdown(); } __dead void resolver_shutdown(void) { /* Close pipes. */ msgbuf_clear(&iev_frontend->ibuf.w); close(iev_frontend->ibuf.fd); msgbuf_clear(&iev_main->ibuf.w); close(iev_main->ibuf.fd); config_clear(resolver_conf); free(iev_frontend); free(iev_main); log_info("resolver exiting"); exit(0); } int resolver_imsg_compose_main(int type, pid_t pid, void *data, uint16_t datalen) { return (imsg_compose_event(iev_main, type, 0, pid, -1, data, datalen)); } int resolver_imsg_compose_frontend(int type, pid_t pid, void *data, uint16_t datalen) { return (imsg_compose_event(iev_frontend, type, 0, pid, -1, data, datalen)); } void resolver_dispatch_frontend(int fd, short event, void *bula) { struct imsgev *iev = bula; struct imsgbuf *ibuf; struct imsg imsg; struct query_imsg *query_imsg; ssize_t n; int shut = 0, verbose, i, new_available_afs; char *ta; ibuf = &iev->ibuf; if (event & EV_READ) { if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) fatal("imsg_read error"); if (n == 0) /* Connection closed. */ shut = 1; } if (event & EV_WRITE) { if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) fatal("msgbuf_write"); if (n == 0) /* Connection closed. */ shut = 1; } for (;;) { if ((n = imsg_get(ibuf, &imsg)) == -1) fatal("%s: imsg_get error", __func__); if (n == 0) /* No more messages. */ break; switch (imsg.hdr.type) { case IMSG_CTL_LOG_VERBOSE: if (IMSG_DATA_SIZE(imsg) != sizeof(verbose)) fatalx("%s: IMSG_CTL_LOG_VERBOSE wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); memcpy(&verbose, imsg.data, sizeof(verbose)); if (log_getdebug() && (log_getverbose() & OPT_VERBOSE3) != (verbose & OPT_VERBOSE3)) restart_ub_resolvers(0); log_setverbose(verbose); break; case IMSG_QUERY: if (IMSG_DATA_SIZE(imsg) != sizeof(*query_imsg)) fatalx("%s: IMSG_QUERY wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); if ((query_imsg = malloc(sizeof(*query_imsg))) == NULL) { log_warn("cannot allocate query"); break; } memcpy(query_imsg, imsg.data, sizeof(*query_imsg)); setup_query(query_imsg); break; case IMSG_CTL_STATUS: if (IMSG_DATA_SIZE(imsg) != 0) fatalx("%s: IMSG_CTL_STATUS wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); show_status(imsg.hdr.pid); break; case IMSG_CTL_AUTOCONF: if (IMSG_DATA_SIZE(imsg) != 0) fatalx("%s: IMSG_CTL_AUTOCONF wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); show_autoconf(imsg.hdr.pid); break; case IMSG_CTL_MEM: if (IMSG_DATA_SIZE(imsg) != 0) fatalx("%s: IMSG_CTL_AUTOCONF wrong length: " "%lu", __func__, IMSG_DATA_SIZE(imsg)); show_mem(imsg.hdr.pid); break; case IMSG_NEW_TA: /* make sure this is a string */ ((char *)imsg.data)[IMSG_DATA_SIZE(imsg) - 1] = '\0'; ta = imsg.data; add_new_ta(&new_trust_anchors, ta); break; case IMSG_NEW_TAS_ABORT: free_tas(&new_trust_anchors); break; case IMSG_NEW_TAS_DONE: if (merge_tas(&new_trust_anchors, &trust_anchors)) restart_ub_resolvers(1); break; case IMSG_NETWORK_CHANGED: clock_gettime(CLOCK_MONOTONIC, &last_network_change); schedule_recheck_all_resolvers(); for (i = 0; i < UW_RES_NONE; i++) { if (resolvers[i] == NULL) continue; memset(resolvers[i]->latest_histogram, 0, sizeof(resolvers[i]->latest_histogram)); resolvers[i]->median = histogram_median( resolvers[i]->latest_histogram); } break; case IMSG_REPLACE_DNS: if (IMSG_DATA_SIZE(imsg) != sizeof(struct imsg_rdns_proposal)) fatalx("%s: IMSG_ADD_DNS wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); replace_autoconf_forwarders((struct imsg_rdns_proposal *)imsg.data); break; case IMSG_CHANGE_AFS: if (IMSG_DATA_SIZE(imsg) != sizeof(new_available_afs)) fatalx("%s: IMSG_CHANGE_AFS wrong length: %lu", __func__, IMSG_DATA_SIZE(imsg)); memcpy(&new_available_afs, imsg.data, sizeof(new_available_afs)); if (new_available_afs != available_afs) { available_afs = new_available_afs; restart_ub_resolvers(1); } break; default: log_debug("%s: unexpected imsg %d", __func__, imsg.hdr.type); break; } imsg_free(&imsg); } if (!shut) imsg_event_add(iev); else { /* This pipe is dead. Remove its event handler. */ event_del(&iev->ev); event_loopexit(NULL); } } void resolver_dispatch_main(int fd, short event, void *bula) { static struct uw_conf *nconf; struct imsg imsg; struct imsgev *iev = bula; struct imsgbuf *ibuf; ssize_t n; int shut = 0, i, *restart; ibuf = &iev->ibuf; if (event & EV_READ) { if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) fatal("imsg_read error"); if (n == 0) /* Connection closed. */ shut = 1; } if (event & EV_WRITE) { if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) fatal("msgbuf_write"); if (n == 0) /* Connection closed. */ shut = 1; } for (;;) { if ((n = imsg_get(ibuf, &imsg)) == -1) fatal("%s: imsg_get error", __func__); if (n == 0) /* No more messages. */ break; switch (imsg.hdr.type) { case IMSG_SOCKET_IPC_FRONTEND: /* * Setup pipe and event handler to the frontend * process. */ if (iev_frontend) fatalx("%s: received unexpected imsg fd " "to resolver", __func__); if ((fd = imsg.fd) == -1) fatalx("%s: expected to receive imsg fd to " "resolver but didn't receive any", __func__); iev_frontend = malloc(sizeof(struct imsgev)); if (iev_frontend == NULL) fatal(NULL); imsg_init(&iev_frontend->ibuf, fd); iev_frontend->handler = resolver_dispatch_frontend; iev_frontend->events = EV_READ; event_set(&iev_frontend->ev, iev_frontend->ibuf.fd, iev_frontend->events, iev_frontend->handler, iev_frontend); event_add(&iev_frontend->ev, NULL); break; case IMSG_STARTUP: if (pledge("stdio inet dns rpath", NULL) == -1) fatal("pledge"); break; case IMSG_RECONF_CONF: case IMSG_RECONF_BLOCKLIST_FILE: case IMSG_RECONF_FORWARDER: case IMSG_RECONF_DOT_FORWARDER: case IMSG_RECONF_FORCE: imsg_receive_config(&imsg, &nconf); break; case IMSG_RECONF_END: if (nconf == NULL) fatalx("%s: IMSG_RECONF_END without " "IMSG_RECONF_CONF", __func__); restart = resolvers_to_restart(resolver_conf, nconf); merge_config(resolver_conf, nconf); memset(enabled_resolvers, 0, sizeof(enabled_resolvers)); for (i = 0; i < resolver_conf->res_pref.len; i++) enabled_resolvers[ resolver_conf->res_pref.types[i]] = 1; nconf = NULL; for (i = 0; i < UW_RES_NONE; i++) if (restart[i]) new_resolver(i, UNKNOWN); break; default: log_debug("%s: unexpected imsg %d", __func__, imsg.hdr.type); break; } imsg_free(&imsg); } if (!shut) imsg_event_add(iev); else { /* This pipe is dead. Remove its event handler. */ event_del(&iev->ev); event_loopexit(NULL); } } int sort_resolver_types(struct resolver_preference *dst) { memcpy(dst, &resolver_conf->res_pref, sizeof(*dst)); /* * Sort by resolver quality, validating > resolving etc. * mergesort is stable and keeps the configured preference order */ return mergesort(dst->types, dst->len, sizeof(dst->types[0]), resolver_cmp); } void setup_query(struct query_imsg *query_imsg) { struct running_query *rq; struct uw_resolver *res; if (find_running_query(query_imsg->id) != NULL) { free(query_imsg); return; } if ((rq = calloc(1, sizeof(*rq))) == NULL) { log_warnx(NULL); free(query_imsg); return; } clock_gettime(CLOCK_MONOTONIC, &rq->tp); rq->query_imsg = query_imsg; rq->next_resolver = 0; find_force(&resolver_conf->force, query_imsg->qname, &res); if (res != NULL && res->state != DEAD && res->state != UNKNOWN) { rq->res_pref.len = 1; rq->res_pref.types[0] = res->type; } else if (sort_resolver_types(&rq->res_pref) == -1) { log_warn("mergesort"); free(rq->query_imsg); free(rq); return; } evtimer_set(&rq->timer_ev, try_resolver_timo, rq); TAILQ_INSERT_TAIL(&running_queries, rq, entry); try_next_resolver(rq); } struct running_query * find_running_query(uint64_t id) { struct running_query *rq; TAILQ_FOREACH(rq, &running_queries, entry) { if (rq->query_imsg->id == id) return rq; } return NULL; } void try_resolver_timo(int fd, short events, void *arg) { struct running_query *rq = arg; try_next_resolver(rq); } int try_next_resolver(struct running_query *rq) { struct uw_resolver *res = NULL; struct query_imsg *query_imsg = NULL; struct timespec tp, elapsed; struct timeval tv = {0, 0}; int64_t ms; while(rq->next_resolver < rq->res_pref.len && ((res = resolvers[rq->res_pref.types[rq->next_resolver]]) == NULL || res->state == DEAD || res->state == UNKNOWN)) rq->next_resolver++; if (res == NULL) { evtimer_del(&rq->timer_ev); /* we are not going to find one */ log_debug("%s: could not find (any more) working resolvers", __func__); goto err; } rq->next_resolver++; clock_gettime(CLOCK_MONOTONIC, &tp); timespecsub(&tp, &rq->tp, &elapsed); ms = elapsed.tv_sec * 1000 + elapsed.tv_nsec / 1000000; log_debug("%s[+%lldms]: %s[%s] %s", __func__, ms, uw_resolver_type_str[res->type], uw_resolver_state_str[res->state], query_imsg2str(rq->query_imsg)); if ((query_imsg = malloc(sizeof(*query_imsg))) == NULL) { log_warnx("%s", __func__); goto err; } memcpy(query_imsg, rq->query_imsg, sizeof(*query_imsg)); clock_gettime(CLOCK_MONOTONIC, &query_imsg->tp); ms = res->median; if (ms > NEXT_RES_MAX) ms = NEXT_RES_MAX; if (res->type == resolver_conf->res_pref.types[0]) tv.tv_usec = 1000 * (PREF_RESOLVER_MEDIAN_SKEW + ms); else tv.tv_usec = 1000 * ms; while (tv.tv_usec >= 1000000) { tv.tv_sec++; tv.tv_usec -= 1000000; } evtimer_add(&rq->timer_ev, &tv); rq->running++; if (resolve(res, query_imsg->qname, query_imsg->t, query_imsg->c, query_imsg, resolve_done) != 0) { rq->running--; goto err; } return 0; err: free(query_imsg); if (rq->running == 0) { TAILQ_REMOVE(&running_queries, rq, entry); evtimer_del(&rq->timer_ev); free(rq->query_imsg); free(rq); } return 1; } int resolve(struct uw_resolver *res, const char* name, int rrtype, int rrclass, void *mydata, resolve_cb_t cb) { struct resolver_cb_data *cb_data = NULL; struct asr_query *aq = NULL; int err; resolver_ref(res); if ((cb_data = malloc(sizeof(*cb_data))) == NULL) goto err; cb_data->cb = cb; cb_data->data = mydata; cb_data->res = res; switch(res->type) { case UW_RES_ASR: if ((aq = res_query_async(name, rrclass, rrtype, res->asr_ctx)) == NULL) { log_warn("%s: res_query_async", __func__); goto err; } if (event_asr_run(aq, asr_resolve_done, cb_data) == NULL) { log_warn("%s: res_query_async", __func__); goto err; } break; case UW_RES_RECURSOR: case UW_RES_DHCP: case UW_RES_ODOT_DHCP: case UW_RES_FORWARDER: case UW_RES_ODOT_FORWARDER: case UW_RES_DOT: if ((err = ub_resolve_event(res->ctx, name, rrtype, rrclass, cb_data, ub_resolve_done, NULL)) != 0) { log_warn("%s: ub_resolve_event: err: %d, %s", __func__, err, ub_strerror(err)); goto err; } break; default: fatalx("unknown resolver type %d", res->type); break; } return 0; err: free(cb_data); free(aq); resolver_unref(res); return 1; } void resolve_done(struct uw_resolver *res, void *arg, int rcode, void *answer_packet, int answer_len, int sec, char *why_bogus) { struct uw_resolver *tmp_res; struct ub_result *result = NULL; sldns_buffer *buf = NULL; struct regional *region = NULL; struct query_imsg *query_imsg; struct answer_header *answer_header; struct running_query *rq; struct timespec tp, elapsed; int64_t ms; size_t i; int running_res, asr_pref_pos, force_acceptbogus; char *str; char rcode_buf[16]; uint8_t *p, *data; uint8_t answer_imsg[MAX_IMSGSIZE - IMSG_HEADER_SIZE]; clock_gettime(CLOCK_MONOTONIC, &tp); query_imsg = (struct query_imsg *)arg; answer_header = (struct answer_header *)answer_imsg; data = answer_imsg + sizeof(*answer_header); answer_header->id = query_imsg->id; answer_header->srvfail = 0; answer_header->answer_len = 0; timespecsub(&tp, &query_imsg->tp, &elapsed); ms = elapsed.tv_sec * 1000 + elapsed.tv_nsec / 1000000; for (i = 0; i < nitems(histogram_limits); i++) { if (ms < histogram_limits[i]) break; } if (i == nitems(histogram_limits)) log_debug("histogram bucket error"); else { res->histogram[i]++; /* latest_histogram is in units of 1000 to avoid rounding down when decaying */ res->latest_histogram[i] += 1000; res->median = histogram_median(res->latest_histogram); } if ((rq = find_running_query(query_imsg->id)) == NULL) goto out; running_res = --rq->running; if (answer_len < LDNS_HEADER_SIZE) { log_warnx("bad packet: too short"); goto servfail; } if (answer_len > UINT16_MAX) { log_warnx("bad packet: too large: %d - %s", answer_len, query_imsg2str(query_imsg)); goto servfail; } answer_header->answer_len = answer_len; if (rcode == LDNS_RCODE_SERVFAIL) { if (res->stop != 1) check_resolver(res); goto servfail; } if ((result = calloc(1, sizeof(*result))) == NULL) goto servfail; if ((buf = sldns_buffer_new(answer_len)) == NULL) goto servfail; if ((region = regional_create()) == NULL) goto servfail; result->rcode = LDNS_RCODE_SERVFAIL; sldns_buffer_clear(buf); sldns_buffer_write(buf, answer_packet, answer_len); sldns_buffer_flip(buf); libworker_enter_result(result, buf, region, sec); result->answer_packet = NULL; result->answer_len = 0; sldns_wire2str_rcode_buf(result->rcode, rcode_buf, sizeof(rcode_buf)); log_debug("%s[%s]: %s rcode: %s[%d], elapsed: %lldms, running: %d", __func__, uw_resolver_type_str[res->type], query_imsg2str(query_imsg), rcode_buf, result->rcode, ms, running_query_cnt()); force_acceptbogus = find_force(&resolver_conf->force, query_imsg->qname, &tmp_res); if (tmp_res != NULL && tmp_res->type != res->type) force_acceptbogus = 0; timespecsub(&tp, &last_network_change, &elapsed); if ((result->rcode == LDNS_RCODE_NXDOMAIN || sec == BOGUS) && !force_acceptbogus && res->type != UW_RES_ASR && elapsed.tv_sec < DOUBT_NXDOMAIN_SEC) { /* * Doubt NXDOMAIN or BOGUS if we just switched networks, we * might be behind a captive portal. */ log_debug("%s: doubt NXDOMAIN or BOGUS from %s, network change" " %llds ago", __func__, uw_resolver_type_str[res->type], elapsed.tv_sec); /* search for ASR */ asr_pref_pos = -1; for (i = 0; i < (size_t)rq->res_pref.len; i++) if (rq->res_pref.types[i] == UW_RES_ASR) { asr_pref_pos = i; break; } if (asr_pref_pos != -1 && resolvers[UW_RES_ASR] != NULL) { /* go to ASR if not yet scheduled */ if (asr_pref_pos >= rq->next_resolver) { rq->next_resolver = asr_pref_pos; try_next_resolver(rq); } goto out; } log_debug("%s: using NXDOMAIN or BOGUS, couldn't find working " "ASR", __func__); } if (log_getverbose() & OPT_VERBOSE2 && (str = sldns_wire2str_pkt(answer_packet, answer_len)) != NULL) { log_debug("%s", str); free(str); } if (result->rcode == LDNS_RCODE_SERVFAIL) goto servfail; if (sec == SECURE && res->state != VALIDATING && res->stop != -1) check_resolver(res); if (res->state == VALIDATING && sec == BOGUS) { answer_header->bogus = !force_acceptbogus; if (answer_header->bogus && why_bogus != NULL) log_warnx("%s", why_bogus); } else answer_header->bogus = 0; p = answer_packet; do { int len; if ((size_t)answer_len > sizeof(answer_imsg) - sizeof(*answer_header)) len = sizeof(answer_imsg) - sizeof(*answer_header); else len = answer_len; memcpy(data, p, len); if (resolver_imsg_compose_frontend(IMSG_ANSWER, 0, &answer_imsg, sizeof(*answer_header) + len) == -1) fatalx("IMSG_ANSWER failed for \"%s\"", query_imsg2str(query_imsg)); answer_len -= len; p += len; } while (answer_len > 0); TAILQ_REMOVE(&running_queries, rq, entry); evtimer_del(&rq->timer_ev); free(rq->query_imsg); free(rq); goto out; servfail: /* try_next_resolver() might free rq */ if (try_next_resolver(rq) != 0 && running_res == 0) { /* we are the last one, send SERVFAIL */ answer_header->srvfail = 1; resolver_imsg_compose_frontend(IMSG_ANSWER, 0, answer_imsg, sizeof(*answer_header)); } out: free(query_imsg); sldns_buffer_free(buf); regional_destroy(region); ub_resolve_free(result); } void new_resolver(enum uw_resolver_type type, enum uw_resolver_state state) { free_resolver(resolvers[type]); resolvers[type] = NULL; if (!enabled_resolvers[type]) return; switch (type) { case UW_RES_ASR: case UW_RES_DHCP: case UW_RES_ODOT_DHCP: if (TAILQ_EMPTY(&autoconf_forwarder_list)) return; break; case UW_RES_RECURSOR: break; case UW_RES_FORWARDER: case UW_RES_ODOT_FORWARDER: if (TAILQ_EMPTY(&resolver_conf->uw_forwarder_list)) return; break; case UW_RES_DOT: if (TAILQ_EMPTY(&resolver_conf->uw_dot_forwarder_list)) return; break; case UW_RES_NONE: fatalx("cannot create UW_RES_NONE resolver"); } switch (type) { case UW_RES_RECURSOR: case UW_RES_DHCP: case UW_RES_ODOT_DHCP: case UW_RES_FORWARDER: case UW_RES_ODOT_FORWARDER: case UW_RES_DOT: if (TAILQ_EMPTY(&trust_anchors)) return; break; case UW_RES_ASR: break; case UW_RES_NONE: fatalx("cannot create UW_RES_NONE resolver"); } if ((resolvers[type] = create_resolver(type)) == NULL) return; switch (state) { case DEAD: case UNKNOWN: check_resolver(resolvers[type]); break; case VALIDATING: set_unified_cache(resolvers[type]); /* FALLTHROUGH */ case RESOLVING: resolvers[type]->state = state; if (type == UW_RES_ASR) check_dns64(); break; } } void set_unified_cache(struct uw_resolver *res) { if (res == NULL || res->ctx == NULL) return; if (res->ctx->env->msg_cache != NULL) { /* XXX we are currently not using this */ if (res->ctx->env->msg_cache != unified_msg_cache || res->ctx->env->rrset_cache != unified_rrset_cache || res->ctx->env->key_cache != unified_key_cache || res->ctx->env->neg_cache != unified_neg_cache) fatalx("wrong unified cache set on resolver"); else /* we are upgrading from UNKNOWN back to VALIDATING */ return; } res->ctx->env->msg_cache = unified_msg_cache; res->ctx->env->rrset_cache = unified_rrset_cache; res->ctx->env->key_cache = unified_key_cache; res->ctx->env->neg_cache = unified_neg_cache; context_finalize(res->ctx); if (res->ctx->env->msg_cache != unified_msg_cache || res->ctx->env->rrset_cache != unified_rrset_cache || res->ctx->env->key_cache != unified_key_cache || res->ctx->env->neg_cache != unified_neg_cache) fatalx("failed to set unified caches, libunbound/validator/" "validator.c diff lost"); } static const struct { const char *name; const char *value; } options[] = { { "aggressive-nsec:", "yes" }, { "fast-server-permil:", "950" }, { "edns-buffer-size:", "1232" }, { "target-fetch-policy:", "0 0 0 0 0" }, { "outgoing-range:", "64" } }; struct uw_resolver * create_resolver(enum uw_resolver_type type) { struct uw_resolver *res; struct trust_anchor *ta; size_t i; int err; char *resolv_conf; if ((res = calloc(1, sizeof(*res))) == NULL) { log_warn("%s", __func__); return (NULL); } res->type = type; res->state = UNKNOWN; res->check_tv.tv_sec = RESOLVER_CHECK_SEC; res->check_tv.tv_usec = arc4random() % 1000000; /* modulo bias is ok */ switch (type) { case UW_RES_ASR: if (TAILQ_EMPTY(&autoconf_forwarder_list)) { free(res); return (NULL); } if ((resolv_conf = gen_resolv_conf()) == NULL) { free(res); log_warnx("could not create asr context"); return (NULL); } if ((res->asr_ctx = asr_resolver_from_string(resolv_conf)) == NULL) { free(res); free(resolv_conf); log_warnx("could not create asr context"); return (NULL); } free(resolv_conf); break; case UW_RES_RECURSOR: case UW_RES_DHCP: case UW_RES_ODOT_DHCP: case UW_RES_FORWARDER: case UW_RES_ODOT_FORWARDER: case UW_RES_DOT: if ((res->ctx = ub_ctx_create_event(ev_base)) == NULL) { free(res); log_warnx("could not create unbound context"); return (NULL); } ub_ctx_debuglevel(res->ctx, log_getverbose() & OPT_VERBOSE3 ? UB_LOG_VERBOSE : UB_LOG_BRIEF); TAILQ_FOREACH(ta, &trust_anchors, entry) { if ((err = ub_ctx_add_ta(res->ctx, ta->ta)) != 0) { ub_ctx_delete(res->ctx); free(res); log_warnx("error adding trust anchor: %s", ub_strerror(err)); return (NULL); } } for (i = 0; i < nitems(options); i++) { if ((err = ub_ctx_set_option(res->ctx, options[i].name, options[i].value)) != 0) { ub_ctx_delete(res->ctx); free(res); log_warnx("error setting %s: %s: %s", options[i].name, options[i].value, ub_strerror(err)); return (NULL); } } if (!(available_afs & HAVE_IPV4)) { if((err = ub_ctx_set_option(res->ctx, "do-ip4:", "no")) != 0) { ub_ctx_delete(res->ctx); free(res); log_warnx("error setting do-ip4: no: %s", ub_strerror(err)); return (NULL); } } if (!(available_afs & HAVE_IPV6)) { if((err = ub_ctx_set_option(res->ctx, "do-ip6:", "no")) != 0) { ub_ctx_delete(res->ctx); free(res); log_warnx("error setting do-ip6: no: %s", ub_strerror(err)); return (NULL); } } if (!log_getdebug()) { if((err = ub_ctx_set_option(res->ctx, "use-syslog:", "no")) != 0) { ub_ctx_delete(res->ctx); free(res); log_warnx("error setting use-syslog: no: %s", ub_strerror(err)); return (NULL); } ub_ctx_debugout(res->ctx, NULL); } break; default: fatalx("unknown resolver type %d", type); break; } evtimer_set(&res->check_ev, resolver_check_timo, res); switch(res->type) { case UW_RES_ASR: break; case UW_RES_RECURSOR: break; case UW_RES_DHCP: set_forwarders(res, &autoconf_forwarder_list, 0); break; case UW_RES_ODOT_DHCP: set_forwarders(res, &autoconf_forwarder_list, 853); ub_ctx_set_option(res->ctx, "tls-cert-bundle:", TLS_DEFAULT_CA_CERT_FILE); ub_ctx_set_tls(res->ctx, 1); break; case UW_RES_FORWARDER: set_forwarders(res, &resolver_conf->uw_forwarder_list, 0); break; case UW_RES_ODOT_FORWARDER: set_forwarders(res, &resolver_conf->uw_forwarder_list, 853); ub_ctx_set_option(res->ctx, "tls-cert-bundle:", TLS_DEFAULT_CA_CERT_FILE); ub_ctx_set_tls(res->ctx, 1); break; case UW_RES_DOT: set_forwarders(res, &resolver_conf->uw_dot_forwarder_list, 0); ub_ctx_set_option(res->ctx, "tls-cert-bundle:", TLS_DEFAULT_CA_CERT_FILE); ub_ctx_set_tls(res->ctx, 1); break; default: fatalx("unknown resolver type %d", type); break; } /* for the forwarder cases allow AS112 zones */ switch(res->type) { case UW_RES_DHCP: case UW_RES_ODOT_DHCP: case UW_RES_FORWARDER: case UW_RES_ODOT_FORWARDER: case UW_RES_DOT: for (i = 0; i < nitems(as112_zones); i++) { if((err = ub_ctx_set_option(res->ctx, "local-zone:", as112_zones[i])) != 0) { ub_ctx_delete(res->ctx); free(res); log_warnx("error setting local-zone: %s: %s", as112_zones[i], ub_strerror(err)); return (NULL); } } break; default: break; } return (res); } void free_resolver(struct uw_resolver *res) { struct val_env *val_env; if (res == NULL) return; if (res->ref_cnt > 0) res->stop = 1; else { evtimer_del(&res->check_ev); if (res->ctx != NULL) { if (res->ctx->env->msg_cache == unified_msg_cache) { val_env = (struct val_env*) res->ctx->env->modinfo[val_id]; res->ctx->env->msg_cache = NULL; res->ctx->env->rrset_cache = NULL; val_env->kcache = NULL; res->ctx->env->key_cache = NULL; val_env->neg_cache = NULL; res->ctx->env->neg_cache = NULL; } } ub_ctx_delete(res->ctx); asr_resolver_free(res->asr_ctx); free(res); } } void setup_unified_caches(void) { struct ub_ctx *ctx; struct val_env *val_env; size_t i; int err, j; if ((ctx = ub_ctx_create_event(ev_base)) == NULL) fatalx("could not create unbound context"); for (i = 0; i < nitems(options); i++) { if ((err = ub_ctx_set_option(ctx, options[i].name, options[i].value)) != 0) { fatalx("error setting %s: %s: %s", options[i].name, options[i].value, ub_strerror(err)); } } context_finalize(ctx); if (ctx->env->msg_cache == NULL || ctx->env->rrset_cache == NULL || ctx->env->key_cache == NULL || ctx->env->neg_cache == NULL) fatalx("could not setup unified caches"); unified_msg_cache = ctx->env->msg_cache; unified_rrset_cache = ctx->env->rrset_cache; unified_key_cache = ctx->env->key_cache; unified_neg_cache = ctx->env->neg_cache; if (val_id == -1) { for (j = 0; j < ctx->mods.num; j++) { if (strcmp(ctx->mods.mod[j]->name, "validator") == 0) { val_id = j; break; } } if (val_id == -1) fatalx("cannot find validator module"); } val_env = (struct val_env*)ctx->env->modinfo[val_id]; ctx->env->msg_cache = NULL; ctx->env->rrset_cache = NULL; ctx->env->key_cache = NULL; val_env->kcache = NULL; ctx->env->neg_cache = NULL; val_env->neg_cache = NULL; ub_ctx_delete(ctx); } void set_forwarders(struct uw_resolver *res, struct uw_forwarder_head *uw_forwarder_list, int port_override) { struct uw_forwarder *uw_forwarder; int ret; char fwd[FWD_MAX]; TAILQ_FOREACH(uw_forwarder, uw_forwarder_list, entry) { if (uw_forwarder->auth_name[0] != '\0') ret = snprintf(fwd, sizeof(fwd), "%s@%d#%s", uw_forwarder->ip, port_override ? port_override : uw_forwarder->port, uw_forwarder->auth_name); else ret = snprintf(fwd, sizeof(fwd), "%s@%d", uw_forwarder->ip, port_override ? port_override : uw_forwarder->port); if (ret < 0 || (size_t)ret >= sizeof(fwd)) { log_warnx("forwarder too long"); continue; } ub_ctx_set_fwd(res->ctx, fwd); } } void resolver_check_timo(int fd, short events, void *arg) { check_resolver((struct uw_resolver *)arg); } void resolver_free_timo(int fd, short events, void *arg) { free_resolver((struct uw_resolver *)arg); } void check_resolver(struct uw_resolver *resolver_to_check) { struct uw_resolver *res; if (resolver_to_check == NULL) return; if (resolver_to_check->check_running) return; if ((res = create_resolver(resolver_to_check->type)) == NULL) return; resolver_ref(resolver_to_check); resolver_to_check->check_running++; if (resolve(res, ".", LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN, resolver_to_check, check_resolver_done) != 0) { resolver_to_check->check_running--; resolver_to_check->state = UNKNOWN; resolver_unref(resolver_to_check); resolver_to_check->check_tv.tv_sec = RESOLVER_CHECK_SEC; evtimer_add(&resolver_to_check->check_ev, &resolver_to_check->check_tv); } } void check_resolver_done(struct uw_resolver *res, void *arg, int rcode, void *answer_packet, int answer_len, int sec, char *why_bogus) { struct uw_resolver *checked_resolver = arg; struct timeval tv = {0, 1}; enum uw_resolver_state prev_state; int bogus_time = 0; char *str; checked_resolver->check_running--; if (checked_resolver != resolvers[checked_resolver->type]) { log_debug("%s: %s: ignoring late check result", __func__, uw_resolver_type_str[checked_resolver->type]); goto out; } prev_state = checked_resolver->state; if (answer_len < LDNS_HEADER_SIZE) { checked_resolver->state = DEAD; log_warnx("%s: bad packet: too short", __func__); goto out; } if (rcode == LDNS_RCODE_SERVFAIL) { log_debug("%s: %s rcode: SERVFAIL", __func__, uw_resolver_type_str[checked_resolver->type]); checked_resolver->state = DEAD; goto out; } if (sec == SECURE) { if (dns64_present && (res->type == UW_RES_DHCP || res->type == UW_RES_ODOT_DHCP)) { /* do not upgrade to validating, DNS64 breaks DNSSEC */ if (prev_state != RESOLVING) new_resolver(checked_resolver->type, RESOLVING); } else { if (prev_state != VALIDATING) new_resolver(checked_resolver->type, VALIDATING); if (!(evtimer_pending(&trust_anchor_timer, NULL))) evtimer_add(&trust_anchor_timer, &tv); } } else if (rcode == LDNS_RCODE_NOERROR && LDNS_RCODE_WIRE((uint8_t*)answer_packet) == LDNS_RCODE_NOERROR) { if (why_bogus) { bogus_time = strncmp(why_bogus, bogus_past, sizeof(bogus_past) - 1) == 0 || strncmp(why_bogus, bogus_future, sizeof(bogus_future) - 1) == 0; log_warnx("%s: %s", uw_resolver_type_str[ checked_resolver->type], why_bogus); } if (prev_state != RESOLVING) new_resolver(checked_resolver->type, RESOLVING); } else checked_resolver->state = DEAD; /* we know the root exists */ log_debug("%s: %s: %s", __func__, uw_resolver_type_str[checked_resolver->type], uw_resolver_state_str[checked_resolver->state]); if (log_getverbose() & OPT_VERBOSE2 && (str = sldns_wire2str_pkt(answer_packet, answer_len)) != NULL) { log_debug("%s", str); free(str); } out: if (!checked_resolver->stop && (checked_resolver->state == DEAD || bogus_time)) { if (prev_state == DEAD || bogus_time) checked_resolver->check_tv.tv_sec *= 2; else checked_resolver->check_tv.tv_sec = RESOLVER_CHECK_SEC; if (checked_resolver->check_tv.tv_sec > RESOLVER_CHECK_MAXSEC) checked_resolver->check_tv.tv_sec = RESOLVER_CHECK_MAXSEC; evtimer_add(&checked_resolver->check_ev, &checked_resolver->check_tv); } resolver_unref(checked_resolver); res->stop = 1; /* do not free in callback */ } void asr_resolve_done(struct asr_result *ar, void *arg) { struct resolver_cb_data *cb_data = arg; cb_data->cb(cb_data->res, cb_data->data, ar->ar_rcode, ar->ar_data, ar->ar_datalen, 0, NULL); free(ar->ar_data); resolver_unref(cb_data->res); free(cb_data); } void ub_resolve_done(void *arg, int rcode, void *answer_packet, int answer_len, int sec, char *why_bogus, int was_ratelimited) { struct resolver_cb_data *cb_data = arg; cb_data->cb(cb_data->res, cb_data->data, rcode, answer_packet, answer_len, sec, why_bogus); resolver_unref(cb_data->res); free(cb_data); } void schedule_recheck_all_resolvers(void) { struct timeval tv; int i; tv.tv_sec = 0; for (i = 0; i < UW_RES_NONE; i++) { if (resolvers[i] == NULL) continue; tv.tv_usec = arc4random() % 1000000; /* modulo bias is ok */ resolvers[i]->state = UNKNOWN; evtimer_add(&resolvers[i]->check_ev, &tv); } } int check_forwarders_changed(struct uw_forwarder_head *list_a, struct uw_forwarder_head *list_b) { struct uw_forwarder *a, *b; a = TAILQ_FIRST(list_a); b = TAILQ_FIRST(list_b); while(a != NULL && b != NULL) { if (strcmp(a->ip, b->ip) != 0) return 1; if (a->port != b->port) return 1; if (strcmp(a->auth_name, b->auth_name) != 0) return 1; a = TAILQ_NEXT(a, entry); b = TAILQ_NEXT(b, entry); } if (a != NULL || b != NULL) return 1; return 0; } void resolver_ref(struct uw_resolver *res) { if (res->ref_cnt == INT_MAX) fatalx("%s: INT_MAX references", __func__); res->ref_cnt++; } void resolver_unref(struct uw_resolver *res) { struct timeval tv = { 0, 1}; if (res->ref_cnt == 0) fatalx("%s: unreferenced resolver", __func__); res->ref_cnt--; /* * Decouple from libunbound event callback. * If we free the ctx inside of resolve_done or check_resovler_done * we are cutting of the branch we are sitting on and hit a * user-after-free */ if (res->stop && res->ref_cnt == 0) { evtimer_set(&res->free_ev, resolver_free_timo, res); evtimer_add(&res->free_ev, &tv); } } void replace_forwarders(struct uw_forwarder_head *new_list, struct uw_forwarder_head *old_list) { struct uw_forwarder *uw_forwarder; while ((uw_forwarder = TAILQ_FIRST(old_list)) != NULL) { TAILQ_REMOVE(old_list, uw_forwarder, entry); free(uw_forwarder); } TAILQ_CONCAT(old_list, new_list, entry); } int resolver_cmp(const void *_a, const void *_b) { const enum uw_resolver_type a = *(const enum uw_resolver_type *)_a; const enum uw_resolver_type b = *(const enum uw_resolver_type *)_b; int64_t a_median, b_median; if (resolvers[a] == NULL && resolvers[b] == NULL) return 0; if (resolvers[b] == NULL) return -1; if (resolvers[a] == NULL) return 1; if (resolvers[a]->state < resolvers[b]->state) return 1; else if (resolvers[a]->state > resolvers[b]->state) return -1; else { a_median = resolvers[a]->median; b_median = resolvers[b]->median; if (resolvers[a]->type == resolver_conf->res_pref.types[0]) a_median -= PREF_RESOLVER_MEDIAN_SKEW; else if (resolvers[b]->type == resolver_conf->res_pref.types[0]) b_median -= PREF_RESOLVER_MEDIAN_SKEW; if (a_median < b_median) return -1; else if (a_median > b_median) return 1; else return 0; } } void restart_ub_resolvers(int recheck) { int i; enum uw_resolver_state state; for (i = 0; i < UW_RES_NONE; i++) { if (i == UW_RES_ASR) continue; if (recheck || resolvers[i] == NULL) state = UNKNOWN; else state = resolvers[i]->state; new_resolver(i, state); } } void show_status(pid_t pid) { struct resolver_preference res_pref; int i; if (sort_resolver_types(&res_pref) == -1) log_warn("mergesort"); for (i = 0; i < resolver_conf->res_pref.len; i++) send_resolver_info(resolvers[res_pref.types[i]], pid); resolver_imsg_compose_frontend(IMSG_CTL_END, pid, NULL, 0); } void show_autoconf(pid_t pid) { struct uw_forwarder *uw_forwarder; struct ctl_forwarder_info cfi; TAILQ_FOREACH(uw_forwarder, &autoconf_forwarder_list, entry) { memset(&cfi, 0, sizeof(cfi)); cfi.if_index = uw_forwarder->if_index; cfi.src = uw_forwarder->src; /* no truncation, structs are in sync */ memcpy(cfi.ip, uw_forwarder->ip, sizeof(cfi.ip)); resolver_imsg_compose_frontend( IMSG_CTL_AUTOCONF_RESOLVER_INFO, pid, &cfi, sizeof(cfi)); } resolver_imsg_compose_frontend(IMSG_CTL_END, pid, NULL, 0); } void show_mem(pid_t pid) { struct ctl_mem_info cmi; memset(&cmi, 0, sizeof(cmi)); cmi.msg_cache_used = slabhash_get_mem(unified_msg_cache); cmi.msg_cache_max = slabhash_get_size(unified_msg_cache); cmi.rrset_cache_used = slabhash_get_mem(&unified_rrset_cache->table); cmi.rrset_cache_max = slabhash_get_size(&unified_rrset_cache->table); cmi.key_cache_used = slabhash_get_mem(unified_key_cache->slab); cmi.key_cache_max = slabhash_get_size(unified_key_cache->slab); cmi.neg_cache_used = unified_neg_cache->use; cmi.neg_cache_max = unified_neg_cache->max; resolver_imsg_compose_frontend(IMSG_CTL_MEM_INFO, pid, &cmi, sizeof(cmi)); } void send_resolver_info(struct uw_resolver *res, pid_t pid) { struct ctl_resolver_info cri; size_t i; if (res == NULL) return; cri.state = res->state; cri.type = res->type; cri.median = res->median; memcpy(cri.histogram, res->histogram, sizeof(cri.histogram)); memcpy(cri.latest_histogram, res->latest_histogram, sizeof(cri.latest_histogram)); for (i = 0; i < nitems(histogram_limits); i++) cri.latest_histogram[i] = (cri.latest_histogram[i] + 500) / 1000; resolver_imsg_compose_frontend(IMSG_CTL_RESOLVER_INFO, pid, &cri, sizeof(cri)); } void trust_anchor_resolve(void) { struct resolver_preference res_pref; struct uw_resolver *res; struct timeval tv = {TRUST_ANCHOR_RETRY_INTERVAL, 0}; if (sort_resolver_types(&res_pref) == -1) log_warn("mergesort"); res = resolvers[res_pref.types[0]]; if (res == NULL || res->state < VALIDATING) goto err; if (resolve(res, ".", LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN, NULL, trust_anchor_resolve_done) != 0) goto err; return; err: evtimer_add(&trust_anchor_timer, &tv); } void trust_anchor_timo(int fd, short events, void *arg) { trust_anchor_resolve(); } void trust_anchor_resolve_done(struct uw_resolver *res, void *arg, int rcode, void *answer_packet, int answer_len, int sec, char *why_bogus) { struct ub_result *result = NULL; sldns_buffer *buf = NULL; struct regional *region = NULL; struct timeval tv = {TRUST_ANCHOR_RETRY_INTERVAL, 0}; int i, tas, n; uint16_t dnskey_flags; char rdata_buf[1024], *ta; if (answer_len < LDNS_HEADER_SIZE) { log_warnx("bad packet: too short"); goto out; } if ((result = calloc(1, sizeof(*result))) == NULL) goto out; if (sec != SECURE) goto out; if ((buf = sldns_buffer_new(answer_len)) == NULL) goto out; if ((region = regional_create()) == NULL) goto out; result->rcode = LDNS_RCODE_SERVFAIL; sldns_buffer_clear(buf); sldns_buffer_write(buf, answer_packet, answer_len); sldns_buffer_flip(buf); libworker_enter_result(result, buf, region, sec); result->answer_packet = NULL; result->answer_len = 0; if (result->rcode != LDNS_RCODE_NOERROR) goto out; i = 0; tas = 0; while(result->data[i] != NULL) { if (result->len[i] < 2) { if (tas > 0) resolver_imsg_compose_frontend( IMSG_NEW_TAS_ABORT, 0, NULL, 0); goto out; } n = sldns_wire2str_rdata_buf(result->data[i], result->len[i], rdata_buf, sizeof(rdata_buf), LDNS_RR_TYPE_DNSKEY); if (n < 0 || (size_t)n >= sizeof(rdata_buf)) { log_warnx("trust anchor buffer to small"); resolver_imsg_compose_frontend(IMSG_NEW_TAS_ABORT, 0, NULL, 0); goto out; } memcpy(&dnskey_flags, result->data[i], 2); dnskey_flags = ntohs(dnskey_flags); if ((dnskey_flags & LDNS_KEY_SEP_KEY) && !(dnskey_flags & LDNS_KEY_REVOKE_KEY)) { asprintf(&ta, ".\t%d\tIN\tDNSKEY\t%s", ROOT_DNSKEY_TTL, rdata_buf); resolver_imsg_compose_frontend(IMSG_NEW_TA, 0, ta, strlen(ta) + 1); tas++; free(ta); } i++; } if (tas > 0) { resolver_imsg_compose_frontend(IMSG_NEW_TAS_DONE, 0, NULL, 0); tv.tv_sec = TRUST_ANCHOR_QUERY_INTERVAL; } out: sldns_buffer_free(buf); regional_destroy(region); ub_resolve_free(result); evtimer_add(&trust_anchor_timer, &tv); } void replace_autoconf_forwarders(struct imsg_rdns_proposal *rdns_proposal) { struct uw_forwarder_head new_forwarder_list; struct uw_forwarder *uw_forwarder, *tmp; int i, rdns_count, af, changed = 0; char ntopbuf[INET6_ADDRSTRLEN], *src; const char *ns; TAILQ_INIT(&new_forwarder_list); af = rdns_proposal->rtdns.sr_family; src = rdns_proposal->rtdns.sr_dns; switch (af) { case AF_INET: rdns_count = (rdns_proposal->rtdns.sr_len - offsetof(struct sockaddr_rtdns, sr_dns)) / sizeof(struct in_addr); break; case AF_INET6: rdns_count = (rdns_proposal->rtdns.sr_len - offsetof(struct sockaddr_rtdns, sr_dns)) / sizeof(struct in6_addr); break; default: log_warnx("%s: unsupported address family: %d", __func__, af); return; } for (i = 0; i < rdns_count; i++) { struct in_addr addr4; struct in6_addr addr6; switch (af) { case AF_INET: memcpy(&addr4, src, sizeof(struct in_addr)); src += sizeof(struct in_addr); if (addr4.s_addr == INADDR_LOOPBACK) continue; ns = inet_ntop(af, &addr4, ntopbuf, INET6_ADDRSTRLEN); break; case AF_INET6: memcpy(&addr6, src, sizeof(struct in6_addr)); src += sizeof(struct in6_addr); if (IN6_IS_ADDR_LOOPBACK(&addr6)) continue; ns = inet_ntop(af, &addr6, ntopbuf, INET6_ADDRSTRLEN); } if ((uw_forwarder = calloc(1, sizeof(struct uw_forwarder))) == NULL) fatal(NULL); if (strlcpy(uw_forwarder->ip, ns, sizeof(uw_forwarder->ip)) >= sizeof(uw_forwarder->ip)) fatalx("strlcpy"); uw_forwarder->port = 53; uw_forwarder->if_index = rdns_proposal->if_index; uw_forwarder->src = rdns_proposal->src; TAILQ_INSERT_TAIL(&new_forwarder_list, uw_forwarder, entry); } TAILQ_FOREACH(tmp, &autoconf_forwarder_list, entry) { /* * if_index of zero signals to clear all proposals * src of zero signals interface gone */ if ((rdns_proposal->src == 0 || rdns_proposal->src == tmp->src) && (rdns_proposal->if_index == 0 || rdns_proposal->if_index == tmp->if_index)) continue; if ((uw_forwarder = calloc(1, sizeof(struct uw_forwarder))) == NULL) fatal(NULL); if (strlcpy(uw_forwarder->ip, tmp->ip, sizeof(uw_forwarder->ip)) >= sizeof(uw_forwarder->ip)) fatalx("strlcpy"); uw_forwarder->port = tmp->port; uw_forwarder->src = tmp->src; uw_forwarder->if_index = tmp->if_index; TAILQ_INSERT_TAIL(&new_forwarder_list, uw_forwarder, entry); } changed = check_forwarders_changed(&new_forwarder_list, &autoconf_forwarder_list); if (changed) { replace_forwarders(&new_forwarder_list, &autoconf_forwarder_list); new_resolver(UW_RES_ASR, UNKNOWN); new_resolver(UW_RES_DHCP, UNKNOWN); new_resolver(UW_RES_ODOT_DHCP, UNKNOWN); } else { while ((tmp = TAILQ_FIRST(&new_forwarder_list)) != NULL) { TAILQ_REMOVE(&new_forwarder_list, tmp, entry); free(tmp); } } } int force_tree_cmp(struct force_tree_entry *a, struct force_tree_entry *b) { return strcasecmp(a->domain, b->domain); } int find_force(struct force_tree *tree, char *qname, struct uw_resolver **res) { struct force_tree_entry *n, e; char *p; if (res) *res = NULL; if (RB_EMPTY(tree)) return 0; p = qname; do { if (strlcpy(e.domain, p, sizeof(e.domain)) >= sizeof(e.domain)) fatal("qname too large"); n = RB_FIND(force_tree, tree, &e); if (n != NULL) { log_debug("%s: %s -> %s[%s]", __func__, qname, p, uw_resolver_type_str[n->type]); if (res) *res = resolvers[n->type]; return n->acceptbogus; } if (*p == '.') p++; p = strchr(p, '.'); if (p != NULL && p[1] != '\0') p++; } while (p != NULL); return 0; } int64_t histogram_median(int64_t *histogram) { size_t i; int64_t sample_count = 0, running_count = 0; /* skip first bucket, it contains cache hits */ for (i = 1; i < nitems(histogram_limits); i++) sample_count += histogram[i]; if (sample_count == 0) return 0; for (i = 1; i < nitems(histogram_limits); i++) { running_count += histogram[i]; if (running_count >= sample_count / 2) break; } if (i >= nitems(histogram_limits) - 1) return INT64_MAX; return (histogram_limits[i - 1] + histogram_limits[i]) / 2; } void decay_latest_histograms(int fd, short events, void *arg) { enum uw_resolver_type i; size_t j; struct uw_resolver *res; struct timeval tv = {DECAY_PERIOD, 0}; for (i = 0; i < UW_RES_NONE; i++) { res = resolvers[i]; if (res == NULL) continue; for (j = 0; j < nitems(res->latest_histogram); j++) /* multiply then divide, avoiding truncating to 0 */ res->latest_histogram[j] = res->latest_histogram[j] * DECAY_NOMINATOR / DECAY_DENOMINATOR; res->median = histogram_median(res->latest_histogram); } evtimer_add(&decay_timer, &tv); } int running_query_cnt(void) { struct running_query *e; int cnt = 0; TAILQ_FOREACH(e, &running_queries, entry) cnt++; return cnt; } int * resolvers_to_restart(struct uw_conf *oconf, struct uw_conf *nconf) { static int restart[UW_RES_NONE]; int o_enabled[UW_RES_NONE]; int n_enabled[UW_RES_NONE]; int i; memset(&restart, 0, sizeof(restart)); if (check_forwarders_changed(&oconf->uw_forwarder_list, &nconf->uw_forwarder_list)) { restart[UW_RES_FORWARDER] = 1; restart[UW_RES_ODOT_FORWARDER] = 1; } if (check_forwarders_changed(&oconf->uw_dot_forwarder_list, &nconf->uw_dot_forwarder_list)) { restart[UW_RES_DOT] = 1; } memset(o_enabled, 0, sizeof(o_enabled)); memset(n_enabled, 0, sizeof(n_enabled)); for (i = 0; i < oconf->res_pref.len; i++) o_enabled[oconf->res_pref.types[i]] = 1; for (i = 0; i < nconf->res_pref.len; i++) n_enabled[nconf->res_pref.types[i]] = 1; for (i = 0; i < UW_RES_NONE; i++) { if (n_enabled[i] != o_enabled[i]) restart[i] = 1; } return restart; } const char * query_imsg2str(struct query_imsg *query_imsg) { static char buf[sizeof(query_imsg->qname) + 1 + 16 + 1 + 16]; char qclass_buf[16]; char qtype_buf[16]; sldns_wire2str_class_buf(query_imsg->c, qclass_buf, sizeof(qclass_buf)); sldns_wire2str_type_buf(query_imsg->t, qtype_buf, sizeof(qtype_buf)); snprintf(buf, sizeof(buf), "%s %s %s", query_imsg->qname, qclass_buf, qtype_buf); return buf; } char * gen_resolv_conf() { struct uw_forwarder *uw_forwarder; char *resolv_conf = NULL, *tmp = NULL; TAILQ_FOREACH(uw_forwarder, &autoconf_forwarder_list, entry) { tmp = resolv_conf; if (asprintf(&resolv_conf, "%snameserver %s\n", tmp == NULL ? "" : tmp, uw_forwarder->ip) == -1) { free(tmp); return (NULL); } free(tmp); } return resolv_conf; } void check_dns64(void) { struct asr_query *aq = NULL; char *resolv_conf; void *asr_ctx; if (TAILQ_EMPTY(&autoconf_forwarder_list)) return; if ((resolv_conf = gen_resolv_conf()) == NULL) { log_warnx("could not create asr context"); return; } if ((asr_ctx = asr_resolver_from_string(resolv_conf)) != NULL) { if ((aq = res_query_async("ipv4only.arpa", LDNS_RR_CLASS_IN, LDNS_RR_TYPE_AAAA, asr_ctx)) == NULL) { log_warn("%s: res_query_async", __func__); asr_resolver_free(asr_ctx); } if (event_asr_run(aq, check_dns64_done, asr_ctx) == NULL) { log_warn("%s: event_asr_run", __func__); free(aq); asr_resolver_free(asr_ctx); } } else log_warnx("%s: could not create asr context", __func__); free(resolv_conf); } void check_dns64_done(struct asr_result *ar, void *arg) { /* RFC 7050: ipv4only.arpa resolves to 192.0.0.170 and 192.9.0.171 */ const uint8_t wka1[] = {192, 0, 0, 170}; const uint8_t wka2[] = {192, 0, 0, 171}; struct query_info skip, qinfo; struct reply_info *rinfo = NULL; struct regional *region = NULL; struct sldns_buffer *buf = NULL; struct ub_packed_rrset_key *an_rrset = NULL; struct packed_rrset_data *an_rrset_data; struct alloc_cache alloc; struct edns_data edns; struct dns64_prefix *prefixes = NULL; size_t i; int preflen, count = 0; void *asr_ctx = arg; memset(&qinfo, 0, sizeof(qinfo)); alloc_init(&alloc, NULL, 0); if (ar->ar_datalen < LDNS_HEADER_SIZE) { log_warnx("%s: bad packet: too short: %d", __func__, ar->ar_datalen); goto out; } if (ar->ar_datalen > UINT16_MAX) { log_warnx("%s: bad packet: too large: %d", __func__, ar->ar_datalen); goto out; } if (ar->ar_rcode == LDNS_RCODE_NXDOMAIN) { /* XXX this means that the dhcp resolver is broken */ log_debug("%s: NXDOMAIN", __func__); goto out; } if ((buf = sldns_buffer_new(ar->ar_datalen)) == NULL) goto out; if ((region = regional_create()) == NULL) goto out; sldns_buffer_write(buf, ar->ar_data, ar->ar_datalen); sldns_buffer_flip(buf); /* read past query section, no memory is allocated */ if (!query_info_parse(&skip, buf)) goto out; if (reply_info_parse(buf, &alloc, &qinfo, &rinfo, region, &edns) != 0) goto out; if ((an_rrset = reply_find_answer_rrset(&qinfo, rinfo)) == NULL) goto out; an_rrset_data = (struct packed_rrset_data*)an_rrset->entry.data; prefixes = calloc(an_rrset_data->count, sizeof(struct dns64_prefix)); if (prefixes == NULL) goto out; for (i = 0; i < an_rrset_data->count; i++) { struct in6_addr in6; /* check for AAAA record */ if (an_rrset_data->rr_len[i] != 18) /* 2 + 128/8 */ continue; if (an_rrset_data->rr_data[i][0] != 0 && an_rrset_data->rr_data[i][1] != 16) continue; memcpy(&in6, &an_rrset_data->rr_data[i][2], sizeof(in6)); if ((preflen = dns64_prefixlen(&in6, wka1)) != -1) add_dns64_prefix(&in6, preflen, prefixes, an_rrset_data->count, WKA1_FOUND); if ((preflen = dns64_prefixlen(&in6, wka2)) != -1) add_dns64_prefix(&in6, preflen, prefixes, an_rrset_data->count, WKA2_FOUND); } for (i = 0; i < an_rrset_data->count && prefixes[i].flags != 0; i++) if ((prefixes[i].flags & (WKA1_FOUND | WKA2_FOUND)) == (WKA1_FOUND | WKA2_FOUND)) count++; dns64_present = count > 0; if (dns64_present) { /* downgrade DHCP resolvers, DNS64 breaks DNSSEC */ if (resolvers[UW_RES_DHCP] != NULL && resolvers[UW_RES_DHCP]->state == VALIDATING) new_resolver(UW_RES_DHCP, RESOLVING); if (resolvers[UW_RES_ODOT_DHCP] != NULL && resolvers[UW_RES_ODOT_DHCP]->state == VALIDATING) new_resolver(UW_RES_ODOT_DHCP, RESOLVING); } resolver_imsg_compose_frontend(IMSG_NEW_DNS64_PREFIXES_START, 0, &count, sizeof(count)); for (i = 0; i < an_rrset_data->count && prefixes[i].flags != 0; i++) { if ((prefixes[i].flags & (WKA1_FOUND | WKA2_FOUND)) == (WKA1_FOUND | WKA2_FOUND)) { resolver_imsg_compose_frontend(IMSG_NEW_DNS64_PREFIX, 0, &prefixes[i], sizeof(struct dns64_prefix)); } } resolver_imsg_compose_frontend(IMSG_NEW_DNS64_PREFIXES_DONE, 0, NULL, 0); out: free(prefixes); query_info_clear(&qinfo); reply_info_parsedelete(rinfo, &alloc); alloc_clear(&alloc); regional_destroy(region); sldns_buffer_free(buf); free(ar->ar_data); asr_resolver_free(asr_ctx); } int dns64_prefixlen(const struct in6_addr *in6, const uint8_t *wka) { /* RFC 6052, 2.2 */ static const int possible_prefixes[] = {32, 40, 48, 56, 64, 96}; size_t i, j; int found, pos; for (i = 0; i < nitems(possible_prefixes); i++) { pos = possible_prefixes[i] / 8; found = 1; for (j = 0; j < 4 && found; j++, pos++) { if (pos == 8) { if (in6->s6_addr[pos] != 0) found = 0; pos++; } if (in6->s6_addr[pos] != wka[j]) found = 0; } if (found) return possible_prefixes[i]; } return -1; } void add_dns64_prefix(const struct in6_addr *in6, int prefixlen, struct dns64_prefix *prefixes, int prefixes_size, int flag) { struct in6_addr tmp; int i; tmp = *in6; for(i = prefixlen / 8; i < 16; i++) tmp.s6_addr[i] = 0; for (i = 0; i < prefixes_size; i++) { if (prefixes[i].flags == 0) { prefixes[i].in6 = tmp; prefixes[i].prefixlen = prefixlen; prefixes[i].flags |= flag; break; } else if (prefixes[i].prefixlen == prefixlen && memcmp(&prefixes[i].in6, &tmp, sizeof(tmp)) == 0) { prefixes[i].flags |= flag; break; } } }