/src/unbound/libunbound/libunbound.c

Source (jump to first uncovered line)
/*
 * unbound.c - unbound validating resolver public API implementation
 *
 * 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 resolve DNS queries and 
 * validate the answers. Synchronously and asynchronously.
 *
 */

/* include the public api first, it should be able to stand alone */
#include "libunbound/unbound.h"
#include "libunbound/unbound-event.h"
#include "config.h"
#include <ctype.h>
#include "libunbound/context.h"
#include "libunbound/libworker.h"
#include "util/locks.h"
#include "util/config_file.h"
#include "util/alloc.h"
#include "util/module.h"
#include "util/regional.h"
#include "util/log.h"
#include "util/random.h"
#include "util/net_help.h"
#include "util/tube.h"
#include "util/ub_event.h"
#include "util/edns.h"
#include "services/modstack.h"
#include "services/localzone.h"
#include "services/cache/infra.h"
#include "services/cache/rrset.h"
#include "services/authzone.h"
#include "services/listen_dnsport.h"
#include "sldns/sbuffer.h"
#include "iterator/iter_fwd.h"
#include "iterator/iter_hints.h"
#ifdef HAVE_PTHREAD
#include <signal.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif

#if defined(UB_ON_WINDOWS) && defined (HAVE_WINDOWS_H)
#include <windows.h>
#include <iphlpapi.h>
#endif /* UB_ON_WINDOWS */

/** store that the logfile has a debug override */
int ctx_logfile_overridden = 0;

/** create context functionality, but no pipes */
static struct ub_ctx* ub_ctx_create_nopipe(void)
{
  struct ub_ctx* ctx;
#ifdef USE_WINSOCK
  int r;
  WSADATA wsa_data;
#endif
  
  checklock_start();
  if(!ctx_logfile_overridden)
    log_init(NULL, 0, NULL); /* logs to stderr */
  log_ident_set("libunbound");
#ifdef USE_WINSOCK
  if((r = WSAStartup(MAKEWORD(2,2), &wsa_data)) != 0) {
    log_err("could not init winsock. WSAStartup: %s",
      wsa_strerror(r));
    return NULL;
  }
#endif
  verbosity = NO_VERBOSE; /* errors only */
  checklock_start();
  ctx = (struct ub_ctx*)calloc(1, sizeof(*ctx));
  if(!ctx) {
    errno = ENOMEM;
    return NULL;
  }
  alloc_init(&ctx->superalloc, NULL, 0);
  if(!(ctx->seed_rnd = ub_initstate(NULL))) {
    ub_randfree(ctx->seed_rnd);
    free(ctx);
    errno = ENOMEM;
    return NULL;
  }
  lock_basic_init(&ctx->qqpipe_lock);
  lock_basic_init(&ctx->rrpipe_lock);
  lock_basic_init(&ctx->cfglock);
  ctx->env = (struct module_env*)calloc(1, sizeof(*ctx->env));
  if(!ctx->env) {
    ub_randfree(ctx->seed_rnd);
    free(ctx);
    errno = ENOMEM;
    return NULL;
  }
  ctx->env->cfg = config_create_forlib();
  if(!ctx->env->cfg) {
    free(ctx->env);
    ub_randfree(ctx->seed_rnd);
    free(ctx);
    errno = ENOMEM;
    return NULL;
  }
  /* init edns_known_options */
  if(!edns_known_options_init(ctx->env)) {
    config_delete(ctx->env->cfg);
    free(ctx->env);
    ub_randfree(ctx->seed_rnd);
    free(ctx);
    errno = ENOMEM;
    return NULL;
  }
  ctx->env->auth_zones = auth_zones_create();
  if(!ctx->env->auth_zones) {
    edns_known_options_delete(ctx->env);
    config_delete(ctx->env->cfg);
    free(ctx->env);
    ub_randfree(ctx->seed_rnd);
    free(ctx);
    errno = ENOMEM;
    return NULL;
  }
  ctx->env->edns_strings = edns_strings_create();
  if(!ctx->env->edns_strings) {
    auth_zones_delete(ctx->env->auth_zones);
    edns_known_options_delete(ctx->env);
    config_delete(ctx->env->cfg);
    free(ctx->env);
    ub_randfree(ctx->seed_rnd);
    free(ctx);
    errno = ENOMEM;
    return NULL;
  }

  ctx->env->alloc = &ctx->superalloc;
  ctx->env->worker = NULL;
  ctx->env->need_to_validate = 0;
  modstack_init(&ctx->mods);
  ctx->env->modstack = &ctx->mods;
  rbtree_init(&ctx->queries, &context_query_cmp);
  return ctx;
}

struct ub_ctx* 
ub_ctx_create(void)
{
  struct ub_ctx* ctx = ub_ctx_create_nopipe();
  if(!ctx)
    return NULL;
  if((ctx->qq_pipe = tube_create()) == NULL) {
    int e = errno;
    ub_randfree(ctx->seed_rnd);
    config_delete(ctx->env->cfg);
    modstack_call_deinit(&ctx->mods, ctx->env);
    modstack_call_destartup(&ctx->mods, ctx->env);
    modstack_free(&ctx->mods);
    listen_desetup_locks();
    edns_known_options_delete(ctx->env);
    edns_strings_delete(ctx->env->edns_strings);
    free(ctx->env);
    free(ctx);
    errno = e;
    return NULL;
  }
  if((ctx->rr_pipe = tube_create()) == NULL) {
    int e = errno;
    tube_delete(ctx->qq_pipe);
    ub_randfree(ctx->seed_rnd);
    config_delete(ctx->env->cfg);
    modstack_call_deinit(&ctx->mods, ctx->env);
    modstack_call_destartup(&ctx->mods, ctx->env);
    modstack_free(&ctx->mods);
    listen_desetup_locks();
    edns_known_options_delete(ctx->env);
    edns_strings_delete(ctx->env->edns_strings);
    free(ctx->env);
    free(ctx);
    errno = e;
    return NULL;
  }
  return ctx;
}

struct ub_ctx* 
ub_ctx_create_ub_event(struct ub_event_base* ueb)
{
  struct ub_ctx* ctx = ub_ctx_create_nopipe();
  if(!ctx)
    return NULL;
  /* no pipes, but we have the locks to make sure everything works */
  ctx->created_bg = 0;
  ctx->dothread = 1; /* the processing is in the same process,
    makes ub_cancel and ub_ctx_delete do the right thing */
  ctx->event_base = ueb;
  return ctx;
}

struct ub_ctx* 
ub_ctx_create_event(struct event_base* eb)
{
  struct ub_ctx* ctx = ub_ctx_create_nopipe();
  if(!ctx)
    return NULL;
  /* no pipes, but we have the locks to make sure everything works */
  ctx->created_bg = 0;
  ctx->dothread = 1; /* the processing is in the same process,
    makes ub_cancel and ub_ctx_delete do the right thing */
  ctx->event_base = ub_libevent_event_base(eb);
  if (!ctx->event_base) {
    ub_ctx_delete(ctx);
    return NULL;
  }
  ctx->event_base_malloced = 1;
  return ctx;
}
  
/** delete q */
static void
delq(rbnode_type* n, void* ATTR_UNUSED(arg))
{
  struct ctx_query* q = (struct ctx_query*)n;
  context_query_delete(q);
}

/** stop the bg thread */
static void ub_stop_bg(struct ub_ctx* ctx)
{
  /* stop the bg thread */
  lock_basic_lock(&ctx->cfglock);
  if(ctx->created_bg) {
    uint8_t* msg;
    uint32_t len;
    uint32_t cmd = UB_LIBCMD_QUIT;
    lock_basic_unlock(&ctx->cfglock);
    lock_basic_lock(&ctx->qqpipe_lock);
    (void)tube_write_msg(ctx->qq_pipe, (uint8_t*)&cmd, 
      (uint32_t)sizeof(cmd), 0);
    lock_basic_unlock(&ctx->qqpipe_lock);
    lock_basic_lock(&ctx->rrpipe_lock);
    while(tube_read_msg(ctx->rr_pipe, &msg, &len, 0)) {
      /* discard all results except a quit confirm */
      if(context_serial_getcmd(msg, len) == UB_LIBCMD_QUIT) {
        free(msg);
        break;
      }
      free(msg);
    }
    lock_basic_unlock(&ctx->rrpipe_lock);

    /* if bg worker is a thread, wait for it to exit, so that all
     * resources are really gone. */
    lock_basic_lock(&ctx->cfglock);
    if(ctx->dothread) {
      lock_basic_unlock(&ctx->cfglock);
      ub_thread_join(ctx->bg_tid);
    } else {
      lock_basic_unlock(&ctx->cfglock);
#ifndef UB_ON_WINDOWS
      if(waitpid(ctx->bg_pid, NULL, 0) == -1) {
        if(verbosity > 2)
          log_err("waitpid: %s", strerror(errno));
      }
#endif
    }
  }
  else {
    lock_basic_unlock(&ctx->cfglock);
  }
}

void 
ub_ctx_delete(struct ub_ctx* ctx)
{
  struct alloc_cache* a, *na;
  int do_stop = 1;
  if(!ctx) return;

  /* if the delete is called but it has forked, and before the fork
   * the context was finalized, then the bg worker is not stopped
   * from here. There is one worker, but two contexts that refer to
   * it and only one should clean up, the one with getpid == pipe_pid.*/
  if(ctx->created_bg && ctx->pipe_pid != getpid()) {
    do_stop = 0;
#ifndef USE_WINSOCK
    /* Stop events from getting deregistered, if the backend is
     * epoll, the epoll fd is the same as the other process.
     * That process should deregister them. */
    if(ctx->qq_pipe->listen_com)
      ctx->qq_pipe->listen_com->event_added = 0;
    if(ctx->qq_pipe->res_com)
      ctx->qq_pipe->res_com->event_added = 0;
    if(ctx->rr_pipe->listen_com)
      ctx->rr_pipe->listen_com->event_added = 0;
    if(ctx->rr_pipe->res_com)
      ctx->rr_pipe->res_com->event_added = 0;
#endif
  }
  /* see if bg thread is created and if threads have been killed */
  /* no locks, because those may be held by terminated threads */
  /* for processes the read pipe is closed and we see that on read */
#ifdef HAVE_PTHREAD
  if(ctx->created_bg && ctx->dothread && do_stop) {
    if(pthread_kill(ctx->bg_tid, 0) == ESRCH) {
      /* thread has been killed */
      do_stop = 0;
    }
  }
#endif /* HAVE_PTHREAD */
  if(do_stop)
    ub_stop_bg(ctx);
  if(ctx->created_bg && ctx->pipe_pid != getpid() && ctx->thread_worker) {
    /* This delete is happening from a different process. Delete
     * the thread worker from this process memory space. The
     * thread is not there to do so, so it is freed here. */
    struct ub_event_base* evbase = comm_base_internal(
      ctx->thread_worker->base);
    libworker_delete_event(ctx->thread_worker);
    ctx->thread_worker = NULL;
#ifdef USE_MINI_EVENT
    ub_event_base_free(evbase);
#else
    /* cannot event_base_free, because the epoll_fd cleanup
     * in libevent could stop the original event_base in the
     * other process from working. */
    free(evbase);
#endif
  }
  libworker_delete_event(ctx->event_worker);

  modstack_call_deinit(&ctx->mods, ctx->env);
  modstack_call_destartup(&ctx->mods, ctx->env);
  modstack_free(&ctx->mods);
  a = ctx->alloc_list;
  while(a) {
    na = a->super;
    a->super = &ctx->superalloc;
    alloc_clear(a);
    free(a);
    a = na;
  }
  local_zones_delete(ctx->local_zones);
  lock_basic_destroy(&ctx->qqpipe_lock);
  lock_basic_destroy(&ctx->rrpipe_lock);
  lock_basic_destroy(&ctx->cfglock);
  tube_delete(ctx->qq_pipe);
  tube_delete(ctx->rr_pipe);
  if(ctx->env) {
    slabhash_delete(ctx->env->msg_cache);
    rrset_cache_delete(ctx->env->rrset_cache);
    infra_delete(ctx->env->infra_cache);
    config_delete(ctx->env->cfg);
    edns_known_options_delete(ctx->env);
    edns_strings_delete(ctx->env->edns_strings);
    forwards_delete(ctx->env->fwds);
    hints_delete(ctx->env->hints);
    auth_zones_delete(ctx->env->auth_zones);
    free(ctx->env);
  }
  ub_randfree(ctx->seed_rnd);
  alloc_clear(&ctx->superalloc);
  listen_desetup_locks();
  traverse_postorder(&ctx->queries, delq, NULL);
  if(ctx_logfile_overridden) {
    log_file(NULL);
    ctx_logfile_overridden = 0;
  }
  if(ctx->event_base_malloced)
    free(ctx->event_base);
  free(ctx);
#ifdef USE_WINSOCK
  WSACleanup();
#endif
}

int 
ub_ctx_set_option(struct ub_ctx* ctx, const char* opt, const char* val)
{
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_AFTERFINAL;
  }
  if(!config_set_option(ctx->env->cfg, opt, val)) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_SYNTAX;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int
ub_ctx_get_option(struct ub_ctx* ctx, const char* opt, char** str)
{
  int r;
  lock_basic_lock(&ctx->cfglock);
  r = config_get_option_collate(ctx->env->cfg, opt, str);
  lock_basic_unlock(&ctx->cfglock);
  if(r == 0) r = UB_NOERROR;
  else if(r == 1) r = UB_SYNTAX;
  else if(r == 2) r = UB_NOMEM;
  return r;
}

int 
ub_ctx_config(struct ub_ctx* ctx, const char* fname)
{
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_AFTERFINAL;
  }
  if(!config_read(ctx->env->cfg, fname, NULL)) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_SYNTAX;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_ctx_add_ta(struct ub_ctx* ctx, const char* ta)
{
  char* dup = strdup(ta);
  if(!dup) return UB_NOMEM;
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    free(dup);
    return UB_AFTERFINAL;
  }
  if(!cfg_strlist_insert(&ctx->env->cfg->trust_anchor_list, dup)) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOMEM;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_ctx_add_ta_file(struct ub_ctx* ctx, const char* fname)
{
  char* dup = strdup(fname);
  if(!dup) return UB_NOMEM;
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    free(dup);
    return UB_AFTERFINAL;
  }
  if(!cfg_strlist_insert(&ctx->env->cfg->trust_anchor_file_list, dup)) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOMEM;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int ub_ctx_add_ta_autr(struct ub_ctx* ctx, const char* fname)
{
  char* dup = strdup(fname);
  if(!dup) return UB_NOMEM;
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    free(dup);
    return UB_AFTERFINAL;
  }
  if(!cfg_strlist_insert(&ctx->env->cfg->auto_trust_anchor_file_list,
    dup)) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOMEM;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_ctx_trustedkeys(struct ub_ctx* ctx, const char* fname)
{
  char* dup = strdup(fname);
  if(!dup) return UB_NOMEM;
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    free(dup);
    return UB_AFTERFINAL;
  }
  if(!cfg_strlist_insert(&ctx->env->cfg->trusted_keys_file_list, dup)) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOMEM;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int
ub_ctx_debuglevel(struct ub_ctx* ctx, int d)
{
  lock_basic_lock(&ctx->cfglock);
  verbosity = d;
  ctx->env->cfg->verbosity = d;
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int ub_ctx_debugout(struct ub_ctx* ctx, void* out)
{
  lock_basic_lock(&ctx->cfglock);
  log_file((FILE*)out);
  ctx_logfile_overridden = 1;
  ctx->logfile_override = 1;
  ctx->log_out = out;
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_ctx_async(struct ub_ctx* ctx, int dothread)
{
#ifdef THREADS_DISABLED
  if(dothread) /* cannot do threading */
    return UB_NOERROR;
#endif
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    return UB_AFTERFINAL;
  }
  ctx->dothread = dothread;
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_poll(struct ub_ctx* ctx)
{
  /* no need to hold lock while testing for readability. */
  return tube_poll(ctx->rr_pipe);
}

int 
ub_fd(struct ub_ctx* ctx)
{
  return tube_read_fd(ctx->rr_pipe);
}

/** process answer from bg worker */
static int
process_answer_detail(struct ub_ctx* ctx, uint8_t* msg, uint32_t len,
  ub_callback_type* cb, void** cbarg, int* err,
  struct ub_result** res)
{
  struct ctx_query* q;
  if(context_serial_getcmd(msg, len) != UB_LIBCMD_ANSWER) {
    log_err("error: bad data from bg worker %d",
      (int)context_serial_getcmd(msg, len));
    return 0;
  }

  lock_basic_lock(&ctx->cfglock);
  q = context_deserialize_answer(ctx, msg, len, err);
  if(!q) {
    lock_basic_unlock(&ctx->cfglock);
    /* probably simply the lookup that failed, i.e.
     * response returned before cancel was sent out, so noerror */
    return 1;
  }
  log_assert(q->async);

  /* grab cb while locked */
  if(q->cancelled) {
    *cb = NULL;
    *cbarg = NULL;
  } else {
    *cb = q->cb;
    *cbarg = q->cb_arg;
  }
  if(*err) {
    *res = NULL;
    ub_resolve_free(q->res);
  } else {
    /* parse the message, extract rcode, fill result */
    sldns_buffer* buf = sldns_buffer_new(q->msg_len);
    struct regional* region = regional_create();
    *res = q->res;
    (*res)->rcode = LDNS_RCODE_SERVFAIL;
    if(region && buf) {
      sldns_buffer_clear(buf);
      sldns_buffer_write(buf, q->msg, q->msg_len);
      sldns_buffer_flip(buf);
      libworker_enter_result(*res, buf, region,
        q->msg_security);
    }
    (*res)->answer_packet = q->msg;
    (*res)->answer_len = (int)q->msg_len;
    q->msg = NULL;
    sldns_buffer_free(buf);
    regional_destroy(region);
  }
  q->res = NULL;
  /* delete the q from list */
  (void)rbtree_delete(&ctx->queries, q->node.key);
  ctx->num_async--;
  context_query_delete(q);
  lock_basic_unlock(&ctx->cfglock);

  if(*cb) return 2;
  ub_resolve_free(*res);
  return 1;
}

/** process answer from bg worker */
static int
process_answer(struct ub_ctx* ctx, uint8_t* msg, uint32_t len)
{
  int err;
  ub_callback_type cb;
  void* cbarg;
  struct ub_result* res;
  int r;

  r = process_answer_detail(ctx, msg, len, &cb, &cbarg, &err, &res);

  /* no locks held while calling callback, so that library is
   * re-entrant. */
  if(r == 2)
    (*cb)(cbarg, err, res);

  return r;
}

int 
ub_process(struct ub_ctx* ctx)
{
  int r;
  uint8_t* msg;
  uint32_t len;
  while(1) {
    msg = NULL;
    lock_basic_lock(&ctx->rrpipe_lock);
    r = tube_read_msg(ctx->rr_pipe, &msg, &len, 1);
    lock_basic_unlock(&ctx->rrpipe_lock);
    if(r == 0)
      return UB_PIPE;
    else if(r == -1)
      break;
    if(!process_answer(ctx, msg, len)) {
      free(msg);
      return UB_PIPE;
    }
    free(msg);
  }
  return UB_NOERROR;
}

int 
ub_wait(struct ub_ctx* ctx)
{
  int err;
  ub_callback_type cb;
  void* cbarg;
  struct ub_result* res;
  int r;
  uint8_t* msg;
  uint32_t len;
  /* this is basically the same loop as _process(), but with changes.
   * holds the rrpipe lock and waits with tube_wait */
  while(1) {
    lock_basic_lock(&ctx->rrpipe_lock);
    lock_basic_lock(&ctx->cfglock);
    if(ctx->num_async == 0) {
      lock_basic_unlock(&ctx->cfglock);
      lock_basic_unlock(&ctx->rrpipe_lock);
      break;
    }
    lock_basic_unlock(&ctx->cfglock);

    /* keep rrpipe locked, while
     *  o waiting for pipe readable
     *  o parsing message
     *  o possibly decrementing num_async
     * do callback without lock
     */
    r = tube_wait(ctx->rr_pipe);
    if(r) {
      r = tube_read_msg(ctx->rr_pipe, &msg, &len, 1);
      if(r == 0) {
        lock_basic_unlock(&ctx->rrpipe_lock);
        return UB_PIPE;
      }
      if(r == -1) {
        lock_basic_unlock(&ctx->rrpipe_lock);
        continue;
      }
      r = process_answer_detail(ctx, msg, len, 
        &cb, &cbarg, &err, &res);
      lock_basic_unlock(&ctx->rrpipe_lock);
      free(msg);
      if(r == 0)
        return UB_PIPE;
      if(r == 2)
        (*cb)(cbarg, err, res);
    } else {
      lock_basic_unlock(&ctx->rrpipe_lock);
    }
  }
  return UB_NOERROR;
}

int 
ub_resolve(struct ub_ctx* ctx, const char* name, int rrtype, 
  int rrclass, struct ub_result** result)
{
  struct ctx_query* q;
  int r;
  *result = NULL;

  lock_basic_lock(&ctx->cfglock);
  if(!ctx->finalized) {
    r = context_finalize(ctx);
    if(r) {
      lock_basic_unlock(&ctx->cfglock);
      return r;
    }
  }
  /* create new ctx_query and attempt to add to the list */
  lock_basic_unlock(&ctx->cfglock);
  q = context_new(ctx, name, rrtype, rrclass, NULL, NULL, NULL);
  if(!q)
    return UB_NOMEM;
  /* become a resolver thread for a bit */

  r = libworker_fg(ctx, q);
  if(r) {
    lock_basic_lock(&ctx->cfglock);
    (void)rbtree_delete(&ctx->queries, q->node.key);
    context_query_delete(q);
    lock_basic_unlock(&ctx->cfglock);
    return r;
  }
  q->res->answer_packet = q->msg;
  q->res->answer_len = (int)q->msg_len;
  q->msg = NULL;
  *result = q->res;
  q->res = NULL;

  lock_basic_lock(&ctx->cfglock);
  (void)rbtree_delete(&ctx->queries, q->node.key);
  context_query_delete(q);
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_resolve_event(struct ub_ctx* ctx, const char* name, int rrtype, 
  int rrclass, void* mydata, ub_event_callback_type callback,
  int* async_id)
{
  struct ctx_query* q;
  int r;

  if(async_id)
    *async_id = 0;
  lock_basic_lock(&ctx->cfglock);
  if(!ctx->finalized) {
    r = context_finalize(ctx);
    if(r) {
      lock_basic_unlock(&ctx->cfglock);
      return r;
    }
  }
  lock_basic_unlock(&ctx->cfglock);
  if(!ctx->event_worker) {
    ctx->event_worker = libworker_create_event(ctx,
      ctx->event_base);
    if(!ctx->event_worker) {
      return UB_INITFAIL;
    }
  }

  /* set time in case answer comes from cache */
  ub_comm_base_now(ctx->event_worker->base);

  /* create new ctx_query and attempt to add to the list */
  q = context_new(ctx, name, rrtype, rrclass, NULL, callback, mydata);
  if(!q)
    return UB_NOMEM;

  /* attach to mesh */
  if((r=libworker_attach_mesh(ctx, q, async_id)) != 0)
    return r;
  return UB_NOERROR;
}


int 
ub_resolve_async(struct ub_ctx* ctx, const char* name, int rrtype, 
  int rrclass, void* mydata, ub_callback_type callback, int* async_id)
{
  struct ctx_query* q;
  uint8_t* msg = NULL;
  uint32_t len = 0;

  if(async_id)
    *async_id = 0;
  lock_basic_lock(&ctx->cfglock);
  if(!ctx->finalized) {
    int r = context_finalize(ctx);
    if(r) {
      lock_basic_unlock(&ctx->cfglock);
      return r;
    }
  }
  if(!ctx->created_bg) {
    int r;
    ctx->created_bg = 1;
    lock_basic_unlock(&ctx->cfglock);
    r = libworker_bg(ctx);
    if(r) {
      lock_basic_lock(&ctx->cfglock);
      ctx->created_bg = 0;
      lock_basic_unlock(&ctx->cfglock);
      return r;
    }
  } else {
    lock_basic_unlock(&ctx->cfglock);
  }

  /* create new ctx_query and attempt to add to the list */
  q = context_new(ctx, name, rrtype, rrclass, callback, NULL, mydata);
  if(!q)
    return UB_NOMEM;

  /* write over pipe to background worker */
  lock_basic_lock(&ctx->cfglock);
  msg = context_serialize_new_query(q, &len);
  if(!msg) {
    (void)rbtree_delete(&ctx->queries, q->node.key);
    ctx->num_async--;
    context_query_delete(q);
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOMEM;
  }
  if(async_id)
    *async_id = q->querynum;
  lock_basic_unlock(&ctx->cfglock);
  
  lock_basic_lock(&ctx->qqpipe_lock);
  if(!tube_write_msg(ctx->qq_pipe, msg, len, 0)) {
    lock_basic_unlock(&ctx->qqpipe_lock);
    free(msg);
    return UB_PIPE;
  }
  lock_basic_unlock(&ctx->qqpipe_lock);
  free(msg);
  return UB_NOERROR;
}

int 
ub_cancel(struct ub_ctx* ctx, int async_id)
{
  struct ctx_query* q;
  uint8_t* msg = NULL;
  uint32_t len = 0;
  lock_basic_lock(&ctx->cfglock);
  q = (struct ctx_query*)rbtree_search(&ctx->queries, &async_id);
  if(!q || !q->async) {
    /* it is not there, so nothing to do */
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOID;
  }
  log_assert(q->async);
  q->cancelled = 1;
  
  /* delete it */
  if(!ctx->dothread) { /* if forked */
    (void)rbtree_delete(&ctx->queries, q->node.key);
    ctx->num_async--;
    msg = context_serialize_cancel(q, &len);
    context_query_delete(q);
    lock_basic_unlock(&ctx->cfglock);
    if(!msg) {
      return UB_NOMEM;
    }
    /* send cancel to background worker */
    lock_basic_lock(&ctx->qqpipe_lock);
    if(!tube_write_msg(ctx->qq_pipe, msg, len, 0)) {
      lock_basic_unlock(&ctx->qqpipe_lock);
      free(msg);
      return UB_PIPE;
    }
    lock_basic_unlock(&ctx->qqpipe_lock);
    free(msg);
  } else {
    lock_basic_unlock(&ctx->cfglock);
  }
  return UB_NOERROR;
}

void 
ub_resolve_free(struct ub_result* result)
{
  char** p;
  if(!result) return;
  free(result->qname);
  if(result->canonname != result->qname)
    free(result->canonname);
  if(result->data)
    for(p = result->data; *p; p++)
      free(*p);
  free(result->data);
  free(result->len);
  free(result->answer_packet);
  free(result->why_bogus);
  free(result);
}

const char* 
ub_strerror(int err)
{
  switch(err) {
    case UB_NOERROR: return "no error";
    case UB_SOCKET: return "socket io error";
    case UB_NOMEM: return "out of memory";
    case UB_SYNTAX: return "syntax error";
    case UB_SERVFAIL: return "server failure";
    case UB_FORKFAIL: return "could not fork";
    case UB_INITFAIL: return "initialization failure";
    case UB_AFTERFINAL: return "setting change after finalize";
    case UB_PIPE: return "error in pipe communication with async";
    case UB_READFILE: return "error reading file";
    case UB_NOID: return "error async_id does not exist";
    default: return "unknown error";
  }
}

int 
ub_ctx_set_fwd(struct ub_ctx* ctx, const char* addr)
{
  struct sockaddr_storage storage;
  socklen_t stlen;
  struct config_stub* s;
  char* dupl;
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    errno=EINVAL;
    return UB_AFTERFINAL;
  }
  if(!addr) {
    /* disable fwd mode - the root stub should be first. */
    if(ctx->env->cfg->forwards &&
      (ctx->env->cfg->forwards->name &&
      strcmp(ctx->env->cfg->forwards->name, ".") == 0)) {
      s = ctx->env->cfg->forwards;
      ctx->env->cfg->forwards = s->next;
      s->next = NULL;
      config_delstubs(s);
    }
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOERROR;
  }
  lock_basic_unlock(&ctx->cfglock);

  /* check syntax for addr */
  if(!extstrtoaddr(addr, &storage, &stlen, UNBOUND_DNS_PORT)) {
    errno=EINVAL;
    return UB_SYNTAX;
  }
  
  /* it parses, add root stub in front of list */
  lock_basic_lock(&ctx->cfglock);
  if(!ctx->env->cfg->forwards ||
    (ctx->env->cfg->forwards->name &&
    strcmp(ctx->env->cfg->forwards->name, ".") != 0)) {
    s = calloc(1, sizeof(*s));
    if(!s) {
      lock_basic_unlock(&ctx->cfglock);
      errno=ENOMEM;
      return UB_NOMEM;
    }
    s->name = strdup(".");
    if(!s->name) {
      free(s);
      lock_basic_unlock(&ctx->cfglock);
      errno=ENOMEM;
      return UB_NOMEM;
    }
    s->next = ctx->env->cfg->forwards;
    ctx->env->cfg->forwards = s;
  } else {
    log_assert(ctx->env->cfg->forwards);
    log_assert(ctx->env->cfg->forwards->name);
    s = ctx->env->cfg->forwards;
  }
  dupl = strdup(addr);
  if(!dupl) {
    lock_basic_unlock(&ctx->cfglock);
    errno=ENOMEM;
    return UB_NOMEM;
  }
  if(!cfg_strlist_insert(&s->addrs, dupl)) {
    lock_basic_unlock(&ctx->cfglock);
    errno=ENOMEM;
    return UB_NOMEM;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int ub_ctx_set_tls(struct ub_ctx* ctx, int tls)
{
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    errno=EINVAL;
    return UB_AFTERFINAL;
  }
  ctx->env->cfg->ssl_upstream = tls;
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int ub_ctx_set_stub(struct ub_ctx* ctx, const char* zone, const char* addr,
  int isprime)
{
  char* a;
  struct config_stub **prev, *elem;

  /* check syntax for zone name */
  if(zone) {
    uint8_t* nm;
    int nmlabs;
    size_t nmlen;
    if(!parse_dname(zone, &nm, &nmlen, &nmlabs)) {
      errno=EINVAL;
      return UB_SYNTAX;
    }
    free(nm);
  } else {
    zone = ".";
  }

  /* check syntax for addr (if not NULL) */
  if(addr) {
    struct sockaddr_storage storage;
    socklen_t stlen;
    if(!extstrtoaddr(addr, &storage, &stlen, UNBOUND_DNS_PORT)) {
      errno=EINVAL;
      return UB_SYNTAX;
    }
  }

  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    errno=EINVAL;
    return UB_AFTERFINAL;
  }

  /* arguments all right, now find or add the stub */
  prev = &ctx->env->cfg->stubs;
  elem = cfg_stub_find(&prev, zone);
  if(!elem && !addr) {
    /* not found and we want to delete, nothing to do */
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOERROR;
  } else if(elem && !addr) {
    /* found, and we want to delete */
    *prev = elem->next;
    config_delstub(elem);
    lock_basic_unlock(&ctx->cfglock);
    return UB_NOERROR;
  } else if(!elem) {
    /* not found, create the stub entry */
    elem=(struct config_stub*)calloc(1, sizeof(struct config_stub));
    if(elem) elem->name = strdup(zone);
    if(!elem || !elem->name) {
      free(elem);
      lock_basic_unlock(&ctx->cfglock);
      errno = ENOMEM;
      return UB_NOMEM;
    }
    elem->next = ctx->env->cfg->stubs;
    ctx->env->cfg->stubs = elem;
  }

  /* add the address to the list and set settings */
  elem->isprime = isprime;
  a = strdup(addr);
  if(!a) {
    lock_basic_unlock(&ctx->cfglock);
    errno = ENOMEM;
    return UB_NOMEM;
  }
  if(!cfg_strlist_insert(&elem->addrs, a)) {
    lock_basic_unlock(&ctx->cfglock);
    errno = ENOMEM;
    return UB_NOMEM;
  }
  lock_basic_unlock(&ctx->cfglock);
  return UB_NOERROR;
}

int 
ub_ctx_resolvconf(struct ub_ctx* ctx, const char* fname)
{
  FILE* in;
  int numserv = 0;
  char buf[1024];
  char* parse, *addr;
  int r;

  if(fname == NULL) {
#if !defined(UB_ON_WINDOWS) || !defined(HAVE_WINDOWS_H)
    fname = "/etc/resolv.conf";
#else
    FIXED_INFO *info;
    ULONG buflen = sizeof(*info);
    IP_ADDR_STRING *ptr;

    info = (FIXED_INFO *) malloc(sizeof (FIXED_INFO));
    if (info == NULL) 
      return UB_READFILE;

    if (GetNetworkParams(info, &buflen) == ERROR_BUFFER_OVERFLOW) {
      free(info);
      info = (FIXED_INFO *) malloc(buflen);
      if (info == NULL)
        return UB_READFILE;
    }

    if (GetNetworkParams(info, &buflen) == NO_ERROR) {
      int retval=0;
      ptr = &(info->DnsServerList);
      while (ptr) {
        numserv++;
        if((retval=ub_ctx_set_fwd(ctx, 
          ptr->IpAddress.String))!=0) {
          free(info);
          return retval;
        }
        ptr = ptr->Next;
      }
      free(info);
      if (numserv==0)
        return UB_READFILE;
      return UB_NOERROR;
    }
    free(info);
    return UB_READFILE;
#endif /* WINDOWS */
  }
  in = fopen(fname, "r");
  if(!in) {
    /* error in errno! perror(fname) */
    return UB_READFILE;
  }
  while(fgets(buf, (int)sizeof(buf), in)) {
    buf[sizeof(buf)-1] = 0;
    parse=buf;
    while(*parse == ' ' || *parse == '\t')
      parse++;
    if(strncmp(parse, "nameserver", 10) == 0) {
      numserv++;
      parse += 10; /* skip 'nameserver' */
      /* skip whitespace */
      while(*parse == ' ' || *parse == '\t')
        parse++;
      addr = parse;
      /* skip [0-9a-fA-F.:]*, i.e. IP4 and IP6 address */
      while(isxdigit((unsigned char)*parse) || *parse=='.' || *parse==':')
        parse++;
      /* terminate after the address, remove newline */
      *parse = 0;
      
      if((r = ub_ctx_set_fwd(ctx, addr)) != UB_NOERROR) {
        fclose(in);
        return r;
      }
    }
  }
  fclose(in);
  if(numserv == 0) {
    /* from resolv.conf(5) if none given, use localhost */
    return ub_ctx_set_fwd(ctx, "127.0.0.1");
  }
  return UB_NOERROR;
}

int
ub_ctx_hosts(struct ub_ctx* ctx, const char* fname)
{
  FILE* in;
  char buf[1024], ldata[2048];
  char* parse, *addr, *name, *ins;
  lock_basic_lock(&ctx->cfglock);
  if(ctx->finalized) {
    lock_basic_unlock(&ctx->cfglock);
    errno=EINVAL;
    return UB_AFTERFINAL;
  }
  lock_basic_unlock(&ctx->cfglock);
  if(fname == NULL) {
#if defined(UB_ON_WINDOWS) && defined(HAVE_WINDOWS_H)
    /*
     * If this is Windows NT/XP/2K it's in
     * %WINDIR%\system32\drivers\etc\hosts.
     * If this is Windows 95/98/Me it's in %WINDIR%\hosts.
     */
    name = getenv("WINDIR");
    if (name != NULL) {
      int retval=0;
      snprintf(buf, sizeof(buf), "%s%s", name, 
        "\\system32\\drivers\\etc\\hosts");
      if((retval=ub_ctx_hosts(ctx, buf)) !=0 ) {
        snprintf(buf, sizeof(buf), "%s%s", name, 
          "\\hosts");
        retval=ub_ctx_hosts(ctx, buf);
      }
      return retval;
    }
    return UB_READFILE;
#else
    fname = "/etc/hosts";
#endif /* WIN32 */
  }
  in = fopen(fname, "r");
  if(!in) {
    /* error in errno! perror(fname) */
    return UB_READFILE;
  }
  while(fgets(buf, (int)sizeof(buf), in)) {
    buf[sizeof(buf)-1] = 0;
    parse=buf;
    while(*parse == ' ' || *parse == '\t')
      parse++;
    if(*parse == '#')
      continue; /* skip comment */
    /* format: <addr> spaces <name> spaces <name> ... */
    addr = parse;
    /* skip addr */
    while(isxdigit((unsigned char)*parse) || *parse == '.' || *parse == ':')
      parse++;
    if(*parse == '\r')
      parse++;
    if(*parse == '\n' || *parse == 0)
      continue;
    if(*parse == '%') 
      continue; /* ignore macOSX fe80::1%lo0 localhost */
    if(*parse != ' ' && *parse != '\t') {
      /* must have whitespace after address */
      fclose(in);
      errno=EINVAL;
      return UB_SYNTAX;
    }
    *parse++ = 0; /* end delimiter for addr ... */
    /* go to names and add them */
    while(*parse) {
      while(*parse == ' ' || *parse == '\t' || *parse=='\n'
        || *parse=='\r')
        parse++;
      if(*parse == 0 || *parse == '#')
        break;
      /* skip name, allows (too) many printable characters */
      name = parse;
      while('!' <= *parse && *parse <= '~')
        parse++;
      if(*parse)
        *parse++ = 0; /* end delimiter for name */
      snprintf(ldata, sizeof(ldata), "%s %s %s",
        name, str_is_ip6(addr)?"AAAA":"A", addr);
      ins = strdup(ldata);
      if(!ins) {
        /* out of memory */
        fclose(in);
        errno=ENOMEM;
        return UB_NOMEM;
      }
      lock_basic_lock(&ctx->cfglock);
      if(!cfg_strlist_insert(&ctx->env->cfg->local_data, 
        ins)) {
        lock_basic_unlock(&ctx->cfglock);
        fclose(in);
        errno=ENOMEM;
        return UB_NOMEM;
      }
      lock_basic_unlock(&ctx->cfglock);
    }
  }
  fclose(in);
  return UB_NOERROR;
}

/** finalize the context, if not already finalized */
static int ub_ctx_finalize(struct ub_ctx* ctx)
{
  int res = 0;
  lock_basic_lock(&ctx->cfglock);
  if (!ctx->finalized) {
    res = context_finalize(ctx);
  }
  lock_basic_unlock(&ctx->cfglock);
  return res;
}

/* Print local zones and RR data */
int ub_ctx_print_local_zones(struct ub_ctx* ctx)
{   
  int res = ub_ctx_finalize(ctx);
  if (res) return res;

  local_zones_print(ctx->local_zones);

  return UB_NOERROR;
}

/* Add a new zone */
int ub_ctx_zone_add(struct ub_ctx* ctx, const char *zone_name, 
  const char *zone_type)
{
  enum localzone_type t;
  struct local_zone* z;
  uint8_t* nm;
  int nmlabs;
  size_t nmlen;

  int res = ub_ctx_finalize(ctx);
  if (res) return res;

  if(!local_zone_str2type(zone_type, &t)) {
    return UB_SYNTAX;
  }

  if(!parse_dname(zone_name, &nm, &nmlen, &nmlabs)) {
    return UB_SYNTAX;
  }

  lock_rw_wrlock(&ctx->local_zones->lock);
  if((z=local_zones_find(ctx->local_zones, nm, nmlen, nmlabs, 
    LDNS_RR_CLASS_IN))) {
    /* already present in tree */
    lock_rw_wrlock(&z->lock);
    z->type = t; /* update type anyway */
    lock_rw_unlock(&z->lock);
    lock_rw_unlock(&ctx->local_zones->lock);
    free(nm);
    return UB_NOERROR;
  }
  if(!local_zones_add_zone(ctx->local_zones, nm, nmlen, nmlabs, 
    LDNS_RR_CLASS_IN, t)) {
    lock_rw_unlock(&ctx->local_zones->lock);
    return UB_NOMEM;
  }
  lock_rw_unlock(&ctx->local_zones->lock);
  return UB_NOERROR;
}

/* Remove zone */
int ub_ctx_zone_remove(struct ub_ctx* ctx, const char *zone_name)
{   
  struct local_zone* z;
  uint8_t* nm;
  int nmlabs;
  size_t nmlen;

  int res = ub_ctx_finalize(ctx);
  if (res) return res;

  if(!parse_dname(zone_name, &nm, &nmlen, &nmlabs)) {
    return UB_SYNTAX;
  }

  lock_rw_wrlock(&ctx->local_zones->lock);
  if((z=local_zones_find(ctx->local_zones, nm, nmlen, nmlabs, 
    LDNS_RR_CLASS_IN))) {
    /* present in tree */
    local_zones_del_zone(ctx->local_zones, z);
  }
  lock_rw_unlock(&ctx->local_zones->lock);
  free(nm);
  return UB_NOERROR;
}

/* Add new RR data */
int ub_ctx_data_add(struct ub_ctx* ctx, const char *data)
{
  int res = ub_ctx_finalize(ctx);
  if (res) return res;

  res = local_zones_add_RR(ctx->local_zones, data);
  return (!res) ? UB_NOMEM : UB_NOERROR;
}

/* Remove RR data */
int ub_ctx_data_remove(struct ub_ctx* ctx, const char *data)
{
  uint8_t* nm;
  int nmlabs;
  size_t nmlen;
  int res = ub_ctx_finalize(ctx);
  if (res) return res;

  if(!parse_dname(data, &nm, &nmlen, &nmlabs)) 
    return UB_SYNTAX;

  local_zones_del_data(ctx->local_zones, nm, nmlen, nmlabs, 
    LDNS_RR_CLASS_IN);

  free(nm);
  return UB_NOERROR;
}

const char* ub_version(void)
{
  return PACKAGE_VERSION;
}

int 
ub_ctx_set_event(struct ub_ctx* ctx, struct event_base* base) {
  struct ub_event_base* new_base;

  if (!ctx || !ctx->event_base || !base) {
    return UB_INITFAIL;
  }
  if (ub_libevent_get_event_base(ctx->event_base) == base) {
    /* already set */
    return UB_NOERROR;
  }
  
  lock_basic_lock(&ctx->cfglock);
  /* destroy the current worker - safe to pass in NULL */
  libworker_delete_event(ctx->event_worker);
  ctx->event_worker = NULL;
  new_base = ub_libevent_event_base(base);
  if (new_base)
    ctx->event_base = new_base; 
  ctx->created_bg = 0;
  ctx->dothread = 1;
  lock_basic_unlock(&ctx->cfglock);
  return new_base ? UB_NOERROR : UB_INITFAIL;
}

Coverage Report

Created: 2025-08-26 06:35