/*
* services/mesh.c - deal with mesh of query states and handle events for that.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains functions to assist in dealing with a mesh of
* query states. This mesh is supposed to be thread-specific.
* It consists of query states (per qname, qtype, qclass) and connections
* between query states and the super and subquery states, and replies to
* send back to clients.
*/
#include "config.h"
#include "services/mesh.h"
#include "services/outbound_list.h"
#include "services/cache/dns.h"
#include "services/cache/rrset.h"
#include "services/cache/infra.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/module.h"
#include "util/regional.h"
#include "util/data/msgencode.h"
#include "util/timehist.h"
#include "util/fptr_wlist.h"
#include "util/alloc.h"
#include "util/config_file.h"
#include "util/edns.h"
#include "sldns/sbuffer.h"
#include "sldns/wire2str.h"
#include "services/localzone.h"
#include "util/data/dname.h"
#include "respip/respip.h"
#include "services/listen_dnsport.h"
#include "util/timeval_func.h"
/** Compare two views by name */
static int
view_name_compare(const char* v_a, const char* v_b)
{
if(v_a == NULL && v_b == NULL)
return 0;
/* The NULL name is smaller than if the name is set. */
if(v_a == NULL)
return -1;
if(v_b == NULL)
return 1;
return strcmp(v_a, v_b);
}
/**
* Compare two response-ip client info entries for the purpose of mesh state
* compare. It returns 0 if ci_a and ci_b are considered equal; otherwise
* 1 or -1 (they mean 'ci_a is larger/smaller than ci_b', respectively, but
* in practice it should be only used to mean they are different).
* We cannot share the mesh state for two queries if different response-ip
* actions can apply in the end, even if those queries are otherwise identical.
* For this purpose we compare tag lists and tag action lists; they should be
* identical to share the same state.
* For tag data, we don't look into the data content, as it can be
* expensive; unless tag data are not defined for both or they point to the
* exact same data in memory (i.e., they come from the same ACL entry), we
* consider these data different.
* Likewise, if the client info is associated with views, we don't look into
* the views. They are considered different unless they are exactly the same
* even if the views only differ in the names.
*/
static int
client_info_compare(const struct respip_client_info* ci_a,
const struct respip_client_info* ci_b)
{
int cmp;
/** help mesh delete delete mesh states */
static void
mesh_delete_helper(rbnode_type* n)
{
struct mesh_state* mstate = (struct mesh_state*)n->key;
/* perform a full delete, not only 'cleanup' routine,
* because other callbacks expect a clean state in the mesh.
* For 're-entrant' calls */
mesh_state_delete(&mstate->s);
/* but because these delete the items from the tree, postorder
* traversal and rbtree rebalancing do not work together */
}
void
mesh_delete(struct mesh_area* mesh)
{
if(!mesh)
return;
/* free all query states */
while(mesh->all.count)
mesh_delete_helper(mesh->all.root);
timehist_delete(mesh->histogram);
sldns_buffer_free(mesh->qbuf_bak);
free(mesh);
}
int mesh_make_new_space(struct mesh_area* mesh, sldns_buffer* qbuf)
{
struct mesh_state* m = mesh->jostle_first;
/* free space is available */
if(mesh->num_reply_states < mesh->max_reply_states)
return 1;
/* try to kick out a jostle-list item */
if(m && m->reply_list && m->list_select == mesh_jostle_list) {
/* how old is it? */
struct timeval age;
timeval_subtract(&age, mesh->env->now_tv,
&m->reply_list->start_time);
if(timeval_smaller(&mesh->jostle_max, &age)) {
/* its a goner */
log_nametypeclass(VERB_ALGO, "query jostled out to "
"make space for a new one",
m->s.qinfo.qname, m->s.qinfo.qtype,
m->s.qinfo.qclass);
/* backup the query */
if(qbuf) sldns_buffer_copy(mesh->qbuf_bak, qbuf);
/* notify supers */
if(m->super_set.count > 0) {
verbose(VERB_ALGO, "notify supers of failure");
m->s.return_msg = NULL;
m->s.return_rcode = LDNS_RCODE_SERVFAIL;
mesh_walk_supers(mesh, m);
}
mesh->stats_jostled ++;
mesh_state_delete(&m->s);
/* restore the query - note that the qinfo ptr to
* the querybuffer is then correct again. */
if(qbuf) sldns_buffer_copy(qbuf, mesh->qbuf_bak);
return 1;
}
}
/* no space for new item */
return 0;
}
/* Check CNAME chain (if any)
* This is part of tomsg above; no need to check now. */
/* Check security status of the cached answer.
* tomsg above has a subset of these checks, so we are leaving
* these as is.
* In case of bogus or revalidation we don't care to reply here. */
if(must_validate && (msg->rep->security == sec_status_bogus ||
msg->rep->security == sec_status_secure_sentinel_fail)) {
verbose(VERB_ALGO, "Serve expired: bogus answer found in cache");
goto bail_out;
} else if(msg->rep->security == sec_status_unchecked && must_validate) {
verbose(VERB_ALGO, "Serve expired: unchecked entry needs "
"validation");
goto bail_out; /* need to validate cache entry first */
} else if(msg->rep->security == sec_status_secure &&
!reply_all_rrsets_secure(msg->rep) && must_validate) {
verbose(VERB_ALGO, "Serve expired: secure entry"
" changed status");
goto bail_out; /* rrset changed, re-verify */
}
/** Init the serve expired data structure */
static int
mesh_serve_expired_init(struct mesh_state* mstate, int timeout)
{
struct timeval t;
/* Create serve_expired_data if not there yet */
if(!mstate->s.serve_expired_data) {
mstate->s.serve_expired_data = (struct serve_expired_data*)
regional_alloc_zero(
mstate->s.region, sizeof(struct serve_expired_data));
if(!mstate->s.serve_expired_data)
return 0;
}
/* Don't overwrite the function if already set */
mstate->s.serve_expired_data->get_cached_answer =
mstate->s.serve_expired_data->get_cached_answer?
mstate->s.serve_expired_data->get_cached_answer:
&mesh_serve_expired_lookup;
/* In case this timer already popped, start it again */
if(!mstate->s.serve_expired_data->timer && timeout != -1) {
mstate->s.serve_expired_data->timer = comm_timer_create(
mstate->s.env->worker_base, mesh_serve_expired_callback, mstate);
if(!mstate->s.serve_expired_data->timer)
return 0;
#ifndef S_SPLINT_S
t.tv_sec = timeout/1000;
t.tv_usec = (timeout%1000)*1000;
#endif
comm_timer_set(mstate->s.serve_expired_data->timer, &t);
}
return 1;
}
void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
struct respip_client_info* cinfo, uint16_t qflags,
struct edns_data* edns, struct comm_reply* rep, uint16_t qid,
int rpz_passthru)
{
struct mesh_state* s = NULL;
int unique = unique_mesh_state(edns->opt_list_in, mesh->env);
int was_detached = 0;
int was_noreply = 0;
int added = 0;
int timeout = mesh->env->cfg->serve_expired?
mesh->env->cfg->serve_expired_client_timeout:0;
struct sldns_buffer* r_buffer = rep->c->buffer;
uint16_t mesh_flags = qflags&(BIT_RD|BIT_CD);
if(rep->c->tcp_req_info) {
r_buffer = rep->c->tcp_req_info->spool_buffer;
}
if(!infra_wait_limit_allowed(mesh->env->infra_cache, rep,
edns->cookie_valid, mesh->env->cfg)) {
verbose(VERB_ALGO, "Too many queries waiting from the IP. "
"dropping incoming query.");
comm_point_drop_reply(rep);
mesh->num_queries_wait_limit++;
return;
}
if(!unique)
s = mesh_area_find(mesh, cinfo, qinfo, mesh_flags, 0, 0);
/* does this create a new reply state? */
if(!s || s->list_select == mesh_no_list) {
if(!mesh_make_new_space(mesh, rep->c->buffer)) {
verbose(VERB_ALGO, "Too many queries. dropping "
"incoming query.");
comm_point_drop_reply(rep);
mesh->stats_dropped++;
return;
}
/* for this new reply state, the reply address is free,
* so the limit of reply addresses does not stop reply states*/
} else {
/* protect our memory usage from storing reply addresses */
if(mesh->num_reply_addrs > mesh->max_reply_states*16) {
verbose(VERB_ALGO, "Too many requests queued. "
"dropping incoming query.");
comm_point_drop_reply(rep);
mesh->stats_dropped++;
return;
}
}
/* see if it already exists, if not, create one */
if(!s) {
#ifdef UNBOUND_DEBUG
struct rbnode_type* n;
#endif
s = mesh_state_create(mesh->env, qinfo, cinfo,
mesh_flags, 0, 0);
if(!s) {
log_err("mesh_state_create: out of memory; SERVFAIL");
if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL, NULL,
LDNS_RCODE_SERVFAIL, edns, rep, mesh->env->scratch, mesh->env->now_tv))
edns->opt_list_inplace_cb_out = NULL;
error_encode(r_buffer, LDNS_RCODE_SERVFAIL,
qinfo, qid, qflags, edns);
comm_point_send_reply(rep);
return;
}
/* set detached (it is now) */
mesh->num_detached_states++;
if(unique)
mesh_state_make_unique(s);
s->s.rpz_passthru = rpz_passthru;
/* copy the edns options we got from the front */
if(edns->opt_list_in) {
s->s.edns_opts_front_in = edns_opt_copy_region(edns->opt_list_in,
s->s.region);
if(!s->s.edns_opts_front_in) {
log_err("edns_opt_copy_region: out of memory; SERVFAIL");
if(!inplace_cb_reply_servfail_call(mesh->env, qinfo, NULL,
NULL, LDNS_RCODE_SERVFAIL, edns, rep, mesh->env->scratch, mesh->env->now_tv))
edns->opt_list_inplace_cb_out = NULL;
error_encode(r_buffer, LDNS_RCODE_SERVFAIL,
qinfo, qid, qflags, edns);
comm_point_send_reply(rep);
mesh_state_delete(&s->s);
return;
}
}
#ifdef UNBOUND_DEBUG
n =
#else
(void)
#endif
rbtree_insert(&mesh->all, &s->node);
log_assert(n != NULL);
added = 1;
}
if(!s->reply_list && !s->cb_list) {
was_noreply = 1;
if(s->super_set.count == 0) {
was_detached = 1;
}
}
/* add reply to s */
if(!mesh_state_add_reply(s, edns, rep, qid, qflags, qinfo)) {
log_err("mesh_new_client: out of memory; SERVFAIL");
goto servfail_mem;
}
if(rep->c->tcp_req_info) {
if(!tcp_req_info_add_meshstate(rep->c->tcp_req_info, mesh, s)) {
log_err("mesh_new_client: out of memory add tcpreqinfo");
goto servfail_mem;
}
}
if(rep->c->use_h2) {
http2_stream_add_meshstate(rep->c->h2_stream, mesh, s);
}
/* add serve expired timer if required and not already there */
if(timeout && !mesh_serve_expired_init(s, timeout)) {
log_err("mesh_new_client: out of memory initializing serve expired");
goto servfail_mem;
}
#ifdef USE_CACHEDB
if(!timeout && mesh->env->cfg->serve_expired &&
!mesh->env->cfg->serve_expired_client_timeout &&
(mesh->env->cachedb_enabled &&
mesh->env->cfg->cachedb_check_when_serve_expired)) {
if(!mesh_serve_expired_init(s, -1)) {
log_err("mesh_new_client: out of memory initializing serve expired");
goto servfail_mem;
}
}
#endif
infra_wait_limit_inc(mesh->env->infra_cache, rep, *mesh->env->now,
mesh->env->cfg);
/* update statistics */
if(was_detached) {
log_assert(mesh->num_detached_states > 0);
mesh->num_detached_states--;
}
if(was_noreply) {
mesh->num_reply_states ++;
}
mesh->num_reply_addrs++;
if(s->list_select == mesh_no_list) {
/* move to either the forever or the jostle_list */
if(mesh->num_forever_states < mesh->max_forever_states) {
mesh->num_forever_states ++;
mesh_list_insert(s, &mesh->forever_first,
&mesh->forever_last);
s->list_select = mesh_forever_list;
} else {
mesh_list_insert(s, &mesh->jostle_first,
&mesh->jostle_last);
s->list_select = mesh_jostle_list;
}
}
if(added)
mesh_run(mesh, s, module_event_new, NULL);
return;
/* Internal backend routine of mesh_new_prefetch(). It takes one additional
* parameter, 'run', which controls whether to run the prefetch state
* immediately. When this function is called internally 'run' could be
* 0 (false), in which case the new state is only made runnable so it
* will not be run recursively on top of the current state. */
static void mesh_schedule_prefetch(struct mesh_area* mesh,
struct query_info* qinfo, uint16_t qflags, time_t leeway, int run,
int rpz_passthru)
{
/* Explicitly set the BIT_RD regardless of the client's flags. This is
* for a prefetch query (no client attached) but it needs to be treated
* as a recursion query. */
uint16_t mesh_flags = BIT_RD|(qflags&BIT_CD);
struct mesh_state* s = mesh_area_find(mesh, NULL, qinfo,
mesh_flags, 0, 0);
#ifdef UNBOUND_DEBUG
struct rbnode_type* n;
#endif
/* already exists, and for a different purpose perhaps.
* if mesh_no_list, keep it that way. */
if(s) {
/* make it ignore the cache from now on */
if(!s->s.blacklist)
sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
if(s->s.prefetch_leeway < leeway)
s->s.prefetch_leeway = leeway;
return;
}
if(!mesh_make_new_space(mesh, NULL)) {
verbose(VERB_ALGO, "Too many queries. dropped prefetch.");
mesh->stats_dropped ++;
return;
}
s = mesh_state_create(mesh->env, qinfo, NULL, mesh_flags, 0, 0);
if(!s) {
log_err("prefetch mesh_state_create: out of memory");
return;
}
#ifdef UNBOUND_DEBUG
n =
#else
(void)
#endif
rbtree_insert(&mesh->all, &s->node);
log_assert(n != NULL);
/* set detached (it is now) */
mesh->num_detached_states++;
/* make it ignore the cache */
sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
s->s.prefetch_leeway = leeway;
if(s->list_select == mesh_no_list) {
/* move to either the forever or the jostle_list */
if(mesh->num_forever_states < mesh->max_forever_states) {
mesh->num_forever_states ++;
mesh_list_insert(s, &mesh->forever_first,
&mesh->forever_last);
s->list_select = mesh_forever_list;
} else {
mesh_list_insert(s, &mesh->jostle_first,
&mesh->jostle_last);
s->list_select = mesh_jostle_list;
}
}
s->s.rpz_passthru = rpz_passthru;
#ifdef CLIENT_SUBNET
/* Same logic as mesh_schedule_prefetch but tailored to the subnet module logic
* like passing along the comm_reply info. This will be faked into an EDNS
* option for processing by the subnet module if the client has not already
* attached its own ECS data. */
static void mesh_schedule_prefetch_subnet(struct mesh_area* mesh,
struct query_info* qinfo, uint16_t qflags, time_t leeway, int run,
int rpz_passthru, struct sockaddr_storage* addr, struct edns_option* edns_list)
{
struct mesh_state* s = NULL;
struct edns_option* opt = NULL;
#ifdef UNBOUND_DEBUG
struct rbnode_type* n;
#endif
/* Explicitly set the BIT_RD regardless of the client's flags. This is
* for a prefetch query (no client attached) but it needs to be treated
* as a recursion query. */
uint16_t mesh_flags = BIT_RD|(qflags&BIT_CD);
if(!mesh_make_new_space(mesh, NULL)) {
verbose(VERB_ALGO, "Too many queries. dropped prefetch.");
mesh->stats_dropped ++;
return;
}
s = mesh_state_create(mesh->env, qinfo, NULL, mesh_flags, 0, 0);
if(!s) {
log_err("prefetch_subnet mesh_state_create: out of memory");
return;
}
mesh_state_make_unique(s);
opt = edns_opt_list_find(edns_list, mesh->env->cfg->client_subnet_opcode);
if(opt) {
/* Use the client's ECS data */
if(!edns_opt_list_append(&s->s.edns_opts_front_in, opt->opt_code,
opt->opt_len, opt->opt_data, s->s.region)) {
log_err("prefetch_subnet edns_opt_list_append: out of memory");
return;
}
} else {
/* Store the client's address. Later in the subnet module,
* it is decided whether to include an ECS option or not.
*/
s->s.client_addr = *addr;
}
#ifdef UNBOUND_DEBUG
n =
#else
(void)
#endif
rbtree_insert(&mesh->all, &s->node);
log_assert(n != NULL);
/* set detached (it is now) */
mesh->num_detached_states++;
/* make it ignore the cache */
sock_list_insert(&s->s.blacklist, NULL, 0, s->s.region);
s->s.prefetch_leeway = leeway;
if(s->list_select == mesh_no_list) {
/* move to either the forever or the jostle_list */
if(mesh->num_forever_states < mesh->max_forever_states) {
mesh->num_forever_states ++;
mesh_list_insert(s, &mesh->forever_first,
&mesh->forever_last);
s->list_select = mesh_forever_list;
} else {
mesh_list_insert(s, &mesh->jostle_first,
&mesh->jostle_last);
s->list_select = mesh_jostle_list;
}
}
s->s.rpz_passthru = rpz_passthru;
/** copy strlist to region */
static struct config_strlist*
cfg_region_strlist_copy(struct regional* region, struct config_strlist* list)
{
struct config_strlist* result = NULL, *last = NULL, *s = list;
while(s) {
struct config_strlist* n = regional_alloc_zero(region,
sizeof(*n));
if(!n)
return NULL;
n->str = regional_strdup(region, s->str);
if(!n->str)
return NULL;
if(last)
last->next = n;
else result = n;
last = n;
s = s->next;
}
return result;
}
/** Copy the client info to the query region. */
static struct respip_client_info*
mesh_copy_client_info(struct regional* region, struct respip_client_info* cinfo)
{
size_t i;
struct respip_client_info* client_info;
client_info = regional_alloc_init(region, cinfo, sizeof(*cinfo));
if(!client_info)
return NULL;
/* Copy the client_info so that if the configuration changes,
* then the data stays valid. */
if(cinfo->taglist) {
client_info->taglist = regional_alloc_init(region, cinfo->taglist,
cinfo->taglen);
if(!client_info->taglist)
return NULL;
}
if(cinfo->tag_actions) {
client_info->tag_actions = regional_alloc_init(region, cinfo->tag_actions,
cinfo->tag_actions_size);
if(!client_info->tag_actions)
return NULL;
}
if(cinfo->tag_datas) {
client_info->tag_datas = regional_alloc_zero(region,
sizeof(struct config_strlist*)*cinfo->tag_datas_size);
if(!client_info->tag_datas)
return NULL;
for(i=0; i<cinfo->tag_datas_size; i++) {
if(cinfo->tag_datas[i]) {
client_info->tag_datas[i] = cfg_region_strlist_copy(
region, cinfo->tag_datas[i]);
if(!client_info->tag_datas[i])
return NULL;
}
}
}
if(cinfo->view) {
/* Do not copy the view pointer but store a name instead.
* The name is looked up later when done, this means that
* the view tree can be changed, by reloads. */
client_info->view = NULL;
client_info->view_name = regional_strdup(region,
cinfo->view->name);
if(!client_info->view_name)
return NULL;
}
return client_info;
}
int mesh_add_sub(struct module_qstate* qstate, struct query_info* qinfo,
uint16_t qflags, int prime, int valrec, struct module_qstate** newq,
struct mesh_state** sub)
{
/* find it, if not, create it */
struct mesh_area* mesh = qstate->env->mesh;
*sub = mesh_area_find(mesh, NULL, qinfo, qflags,
prime, valrec);
if(mesh_detect_cycle_found(qstate, *sub)) {
verbose(VERB_ALGO, "attach failed, cycle detected");
return 0;
}
if(!*sub) {
#ifdef UNBOUND_DEBUG
struct rbnode_type* n;
#endif
/* create a new one */
*sub = mesh_state_create(qstate->env, qinfo, NULL, qflags, prime,
valrec);
if(!*sub) {
log_err("mesh_attach_sub: out of memory");
return 0;
}
#ifdef UNBOUND_DEBUG
n =
#else
(void)
#endif
rbtree_insert(&mesh->all, &(*sub)->node);
log_assert(n != NULL);
/* set detached (it is now) */
mesh->num_detached_states++;
/* set new query state to run */
#ifdef UNBOUND_DEBUG
n =
#else
(void)
#endif
rbtree_insert(&mesh->run, &(*sub)->run_node);
log_assert(n != NULL);
*newq = &(*sub)->s;
} else
*newq = NULL;
return 1;
}
int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
uint16_t qflags, int prime, int valrec, struct module_qstate** newq)
{
struct mesh_area* mesh = qstate->env->mesh;
struct mesh_state* sub = NULL;
int was_detached;
if(!mesh_add_sub(qstate, qinfo, qflags, prime, valrec, newq, &sub))
return 0;
was_detached = (sub->super_set.count == 0);
if(!mesh_state_attachment(qstate->mesh_info, sub))
return 0;
/* if it was a duplicate attachment, the count was not zero before */
if(!sub->reply_list && !sub->cb_list && was_detached &&
sub->super_set.count == 1) {
/* it used to be detached, before this one got added */
log_assert(mesh->num_detached_states > 0);
mesh->num_detached_states--;
}
/* *newq will be run when inited after the current module stops */
return 1;
}
int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub)
{
#ifdef UNBOUND_DEBUG
struct rbnode_type* n;
#endif
struct mesh_state_ref* subref; /* points to sub, inserted in super */
struct mesh_state_ref* superref; /* points to super, inserted in sub */
if( !(subref = regional_alloc(super->s.region,
sizeof(struct mesh_state_ref))) ||
!(superref = regional_alloc(sub->s.region,
sizeof(struct mesh_state_ref))) ) {
log_err("mesh_state_attachment: out of memory");
return 0;
}
superref->node.key = superref;
superref->s = super;
subref->node.key = subref;
subref->s = sub;
if(!rbtree_insert(&sub->super_set, &superref->node)) {
/* this should not happen, iterator and validator do not
* attach subqueries that are identical. */
/* already attached, we are done, nothing todo.
* since superref and subref already allocated in region,
* we cannot free them */
return 1;
}
#ifdef UNBOUND_DEBUG
n =
#else
(void)
#endif
rbtree_insert(&super->sub_set, &subref->node);
log_assert(n != NULL); /* we checked above if statement, the reverse
administration should not fail now, unless they are out of sync */
return 1;
}
/**
* callback results to mesh cb entry
* @param m: mesh state to send it for.
* @param rcode: if not 0, error code.
* @param rep: reply to send (or NULL if rcode is set).
* @param r: callback entry
* @param start_time: the time to pass to callback functions, it is 0 or
* a value from one of the packets if the mesh state had packets.
*/
static void
mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
struct mesh_cb* r, struct timeval* start_time)
{
int secure;
char* reason = NULL;
int was_ratelimited = m->s.was_ratelimited;
/* bogus messages are not made into servfail, sec_status passed
* to the callback function */
if(rep && rep->security == sec_status_secure)
secure = 1;
else secure = 0;
if(!rep && rcode == LDNS_RCODE_NOERROR)
rcode = LDNS_RCODE_SERVFAIL;
if(!rcode && rep && (rep->security == sec_status_bogus ||
rep->security == sec_status_secure_sentinel_fail)) {
if(!(reason = errinf_to_str_bogus(&m->s, NULL)))
rcode = LDNS_RCODE_SERVFAIL;
}
/* send the reply */
if(rcode) {
if(rcode == LDNS_RCODE_SERVFAIL) {
if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
rep, rcode, &r->edns, NULL, m->s.region, start_time))
r->edns.opt_list_inplace_cb_out = NULL;
} else {
if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
&r->edns, NULL, m->s.region, start_time))
r->edns.opt_list_inplace_cb_out = NULL;
}
fptr_ok(fptr_whitelist_mesh_cb(r->cb));
(*r->cb)(r->cb_arg, rcode, r->buf, sec_status_unchecked, NULL,
was_ratelimited);
} else {
size_t udp_size = r->edns.udp_size;
sldns_buffer_clear(r->buf);
r->edns.edns_version = EDNS_ADVERTISED_VERSION;
r->edns.udp_size = EDNS_ADVERTISED_SIZE;
r->edns.ext_rcode = 0;
r->edns.bits &= EDNS_DO;
if(m->s.env->cfg->disable_edns_do && (r->edns.bits&EDNS_DO))
r->edns.edns_present = 0;
static inline void
mesh_find_and_attach_ede_and_reason(struct mesh_state* m,
struct reply_info* rep, struct mesh_reply* r)
{
/* OLD note:
* During validation the EDE code can be received via two
* code paths. One code path fills the reply_info EDE, and
* the other fills it in the errinf_strlist. These paths
* intersect at some points, but where is opaque due to
* the complexity of the validator. At the time of writing
* we make the choice to prefer the EDE from errinf_strlist
* but a compelling reason to do otherwise is just as valid
* NEW note:
* The compelling reason is that with caching support, the value
* in the reply_info is cached.
* The reason members of the reply_info struct should be
* updated as they are already cached. No reason to
* try and find the EDE information in errinf anymore.
*/
if(rep->reason_bogus != LDNS_EDE_NONE) {
edns_opt_list_append_ede(&r->edns.opt_list_out,
m->s.region, rep->reason_bogus, rep->reason_bogus_str);
}
}
/**
* Send reply to mesh reply entry
* @param m: mesh state to send it for.
* @param rcode: if not 0, error code.
* @param rep: reply to send (or NULL if rcode is set).
* @param r: reply entry
* @param r_buffer: buffer to use for reply entry.
* @param prev: previous reply, already has its answer encoded in buffer.
* @param prev_buffer: buffer for previous reply.
*/
static void
mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
struct mesh_reply* r, struct sldns_buffer* r_buffer,
struct mesh_reply* prev, struct sldns_buffer* prev_buffer)
{
struct timeval end_time;
struct timeval duration;
int secure;
/* briefly set the replylist to null in case the
* meshsendreply calls tcpreqinfo sendreply that
* comm_point_drops because of size, and then the
* null stops the mesh state remove and thus
* reply_list modification and accounting */
struct mesh_reply* rlist = m->reply_list;
/* examine security status */
if(m->s.env->need_to_validate && (!(r->qflags&BIT_CD) ||
m->s.env->cfg->ignore_cd) && rep &&
(rep->security <= sec_status_bogus ||
rep->security == sec_status_secure_sentinel_fail)) {
rcode = LDNS_RCODE_SERVFAIL;
if(m->s.env->cfg->stat_extended)
m->s.env->mesh->ans_bogus++;
}
if(rep && rep->security == sec_status_secure)
secure = 1;
else secure = 0;
if(!rep && rcode == LDNS_RCODE_NOERROR)
rcode = LDNS_RCODE_SERVFAIL;
if(r->query_reply.c->use_h2) {
r->query_reply.c->h2_stream = r->h2_stream;
/* Mesh reply won't exist for long anymore. Make it impossible
* for HTTP/2 stream to refer to mesh state, in case
* connection gets cleanup before HTTP/2 stream close. */
r->h2_stream->mesh_state = NULL;
}
/* send the reply */
/* We don't reuse the encoded answer if:
* - either the previous or current response has a local alias. We could
* compare the alias records and still reuse the previous answer if they
* are the same, but that would be complicated and error prone for the
* relatively minor case. So we err on the side of safety.
* - there are registered callback functions for the given rcode, as these
* need to be called for each reply. */
if(((rcode != LDNS_RCODE_SERVFAIL &&
!m->s.env->inplace_cb_lists[inplace_cb_reply]) ||
(rcode == LDNS_RCODE_SERVFAIL &&
!m->s.env->inplace_cb_lists[inplace_cb_reply_servfail])) &&
prev && prev_buffer && prev->qflags == r->qflags &&
!prev->local_alias && !r->local_alias &&
prev->edns.edns_present == r->edns.edns_present &&
prev->edns.bits == r->edns.bits &&
prev->edns.udp_size == r->edns.udp_size &&
edns_opt_list_compare(prev->edns.opt_list_out, r->edns.opt_list_out) == 0 &&
edns_opt_list_compare(prev->edns.opt_list_inplace_cb_out, r->edns.opt_list_inplace_cb_out) == 0
) {
/* if the previous reply is identical to this one, fix ID */
if(prev_buffer != r_buffer)
sldns_buffer_copy(r_buffer, prev_buffer);
sldns_buffer_write_at(r_buffer, 0, &r->qid, sizeof(uint16_t));
sldns_buffer_write_at(r_buffer, 12, r->qname,
m->s.qinfo.qname_len);
m->reply_list = NULL;
comm_point_send_reply(&r->query_reply);
m->reply_list = rlist;
} else if(rcode) {
m->s.qinfo.qname = r->qname;
m->s.qinfo.local_alias = r->local_alias;
if(rcode == LDNS_RCODE_SERVFAIL) {
if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
rep, rcode, &r->edns, &r->query_reply, m->s.region, &r->start_time))
r->edns.opt_list_inplace_cb_out = NULL;
} else {
if(!inplace_cb_reply_call(m->s.env, &m->s.qinfo, &m->s, rep, rcode,
&r->edns, &r->query_reply, m->s.region, &r->start_time))
r->edns.opt_list_inplace_cb_out = NULL;
}
/* Send along EDE EDNS0 option when SERVFAILing; usually
* DNSSEC validation failures */
/* Since we are SERVFAILing here, CD bit and rep->security
* is already handled. */
if(m->s.env->cfg->ede && rep) {
mesh_find_and_attach_ede_and_reason(m, rep, r);
}
error_encode(r_buffer, rcode, &m->s.qinfo, r->qid,
r->qflags, &r->edns);
m->reply_list = NULL;
comm_point_send_reply(&r->query_reply);
m->reply_list = rlist;
} else {
size_t udp_size = r->edns.udp_size;
r->edns.edns_version = EDNS_ADVERTISED_VERSION;
r->edns.udp_size = EDNS_ADVERTISED_SIZE;
r->edns.ext_rcode = 0;
r->edns.bits &= EDNS_DO;
if(m->s.env->cfg->disable_edns_do && (r->edns.bits&EDNS_DO))
r->edns.edns_present = 0;
m->s.qinfo.qname = r->qname;
m->s.qinfo.local_alias = r->local_alias;
/* Attach EDE without SERVFAIL if the validation failed.
* Need to explicitly check for rep->security otherwise failed
* validation paths may attach to a secure answer. */
if(m->s.env->cfg->ede && rep &&
(rep->security <= sec_status_bogus ||
rep->security == sec_status_secure_sentinel_fail)) {
mesh_find_and_attach_ede_and_reason(m, rep, r);
}
/**
* Generate the DNS Error Report (RFC9567).
* If there is an EDE attached for this reply and there was a Report-Channel
* EDNS0 option from the upstream, fire up a report query.
* @param qstate: module qstate.
* @param rep: prepared reply to be sent.
*/
static void dns_error_reporting(struct module_qstate* qstate,
struct reply_info* rep)
{
struct query_info qinfo;
struct mesh_state* sub;
struct module_qstate* newq;
uint8_t buf[LDNS_MAX_DOMAINLEN];
size_t count = 0;
int written;
size_t expected_length;
struct edns_option* opt;
sldns_ede_code reason_bogus = LDNS_EDE_NONE;
sldns_rr_type qtype = qstate->qinfo.qtype;
uint8_t* qname = qstate->qinfo.qname;
size_t qname_len = qstate->qinfo.qname_len-1; /* skip the trailing \0 */
uint8_t* agent_domain;
size_t agent_domain_len;
/* We need a valid reporting agent;
* this is based on qstate->edns_opts_back_in that will probably have
* the latest reporting agent we found while iterating */
opt = edns_opt_list_find(qstate->edns_opts_back_in,
LDNS_EDNS_REPORT_CHANNEL);
if(!opt) return;
agent_domain_len = opt->opt_len;
agent_domain = opt->opt_data;
if(dname_valid(agent_domain, agent_domain_len) < 3) {
/* The agent domain needs to be a valid dname that is not the
* root; from RFC9567. */
return;
}
/* Get the EDE generated from the mesh state, these are mostly
* validator errors. If other errors are produced in the future (e.g.,
* RPZ) we would not want them to result in error reports. */
reason_bogus = errinf_to_reason_bogus(qstate);
if(rep && ((reason_bogus == LDNS_EDE_DNSSEC_BOGUS &&
rep->reason_bogus != LDNS_EDE_NONE) ||
reason_bogus == LDNS_EDE_NONE)) {
reason_bogus = rep->reason_bogus;
}
if(reason_bogus == LDNS_EDE_NONE ||
/* other, does not make sense without the text that comes
* with it */
reason_bogus == LDNS_EDE_OTHER) return;
/* Synthesize the error report query in the format:
* "_er.$qtype.$qname.$ede._er.$reporting-agent-domain" */
/* First check if the static length parts fit in the buffer.
* That is everything except for qtype and ede that need to be
* converted to decimal and checked further on. */
expected_length = 4/*_er*/+qname_len+4/*_er*/+agent_domain_len;
if(expected_length > LDNS_MAX_DOMAINLEN) goto skip;
memmove(buf+count, "\3_er", 4);
count += 4;
written = snprintf((char*)buf+count, LDNS_MAX_DOMAINLEN-count,
"X%d", qtype);
expected_length += written;
/* Skip on error, truncation or long expected length */
if(written < 0 || (size_t)written >= LDNS_MAX_DOMAINLEN-count ||
expected_length > LDNS_MAX_DOMAINLEN ) goto skip;
/* Put in the label length */
*(buf+count) = (char)(written - 1);
count += written;
for(r = mstate->reply_list; r; r = r->next) {
struct timeval old;
timeval_subtract(&old, mstate->s.env->now_tv, &r->start_time);
if(mstate->s.env->cfg->discard_timeout != 0 &&
((int)old.tv_sec)*1000+((int)old.tv_usec)/1000 >
mstate->s.env->cfg->discard_timeout) {
/* Drop the reply, it is too old */
/* briefly set the reply_list to NULL, so that the
* tcp req info cleanup routine that calls the mesh
* to deregister the meshstate for it is not done
* because the list is NULL and also accounting is not
* done there, but instead we do that here. */
struct mesh_reply* reply_list = mstate->reply_list;
verbose(VERB_ALGO, "drop reply, it is older than discard-timeout");
infra_wait_limit_dec(mstate->s.env->infra_cache,
&r->query_reply, mstate->s.env->cfg);
mstate->reply_list = NULL;
if(r->query_reply.c->use_h2)
http2_stream_remove_mesh_state(r->h2_stream);
comm_point_drop_reply(&r->query_reply);
mstate->reply_list = reply_list;
mstate->s.env->mesh->num_queries_discard_timeout++;
continue;
}
i++;
tv = r->start_time;
/* if a response-ip address block has been stored the
* information should be logged for each client. */
if(mstate->s.respip_action_info &&
mstate->s.respip_action_info->addrinfo) {
respip_inform_print(mstate->s.respip_action_info,
r->qname, mstate->s.qinfo.qtype,
mstate->s.qinfo.qclass, r->local_alias,
&r->query_reply.client_addr,
r->query_reply.client_addrlen);
}
/* if this query is determined to be dropped during the
* mesh processing, this is the point to take that action. */
if(mstate->s.is_drop) {
/* briefly set the reply_list to NULL, so that the
* tcp req info cleanup routine that calls the mesh
* to deregister the meshstate for it is not done
* because the list is NULL and also accounting is not
* done there, but instead we do that here. */
struct mesh_reply* reply_list = mstate->reply_list;
infra_wait_limit_dec(mstate->s.env->infra_cache,
&r->query_reply, mstate->s.env->cfg);
mstate->reply_list = NULL;
if(r->query_reply.c->use_h2) {
http2_stream_remove_mesh_state(r->h2_stream);
}
comm_point_drop_reply(&r->query_reply);
mstate->reply_list = reply_list;
} else {
struct sldns_buffer* r_buffer = r->query_reply.c->buffer;
if(r->query_reply.c->tcp_req_info) {
r_buffer = r->query_reply.c->tcp_req_info->spool_buffer;
prev_buffer = NULL;
}
mesh_send_reply(mstate, mstate->s.return_rcode, rep,
r, r_buffer, prev, prev_buffer);
if(r->query_reply.c->tcp_req_info) {
tcp_req_info_remove_mesh_state(r->query_reply.c->tcp_req_info, mstate);
r_buffer = NULL;
}
/* mesh_send_reply removed mesh state from
* http2_stream. */
prev = r;
prev_buffer = r_buffer;
}
}
/* Account for each reply sent. */
if(i > 0 && mstate->s.respip_action_info &&
mstate->s.respip_action_info->addrinfo &&
mstate->s.env->cfg->stat_extended &&
mstate->s.respip_action_info->rpz_used) {
if(mstate->s.respip_action_info->rpz_disabled)
mstate->s.env->mesh->rpz_action[RPZ_DISABLED_ACTION] += i;
if(mstate->s.respip_action_info->rpz_cname_override)
mstate->s.env->mesh->rpz_action[RPZ_CNAME_OVERRIDE_ACTION] += i;
else
mstate->s.env->mesh->rpz_action[respip_action_to_rpz_action(
mstate->s.respip_action_info->action)] += i;
}
if(!mstate->s.is_drop && i > 0) {
if(mstate->s.env->cfg->stat_extended
&& mstate->s.is_cachedb_answer) {
mstate->s.env->mesh->ans_cachedb += i;
}
}
/* Mesh area accounting */
if(mstate->reply_list) {
mstate->reply_list = NULL;
if(!mstate->reply_list && !mstate->cb_list) {
/* was a reply state, not anymore */
log_assert(mstate->s.env->mesh->num_reply_states > 0);
mstate->s.env->mesh->num_reply_states--;
}
if(!mstate->reply_list && !mstate->cb_list &&
mstate->super_set.count == 0)
mstate->s.env->mesh->num_detached_states++;
}
mstate->replies_sent = 1;
while((c = mstate->cb_list) != NULL) {
/* take this cb off the list; so that the list can be
* changed, eg. by adds from the callback routine */
if(!mstate->reply_list && mstate->cb_list && !c->next) {
/* was a reply state, not anymore */
log_assert(mstate->s.env->mesh->num_reply_states > 0);
mstate->s.env->mesh->num_reply_states--;
}
mstate->cb_list = c->next;
if(!mstate->reply_list && !mstate->cb_list &&
mstate->super_set.count == 0)
mstate->s.env->mesh->num_detached_states++;
mesh_do_callback(mstate, mstate->s.return_rcode, rep, c, &tv);
}
}
void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate)
{
struct mesh_state_ref* ref;
RBTREE_FOR(ref, struct mesh_state_ref*, &mstate->super_set)
{
/* make super runnable */
(void)rbtree_insert(&mesh->run, &ref->s->run_node);
/* callback the function to inform super of result */
fptr_ok(fptr_whitelist_mod_inform_super(
mesh->mods.mod[ref->s->s.curmod]->inform_super));
(*mesh->mods.mod[ref->s->s.curmod]->inform_super)(&mstate->s,
ref->s->s.curmod, &ref->s->s);
/* copy state that is always relevant to super */
copy_state_to_super(&mstate->s, ref->s->s.curmod, &ref->s->s);
}
}
key.node.key = &key;
key.s.is_priming = prime;
key.s.is_valrec = valrec;
key.s.qinfo = *qinfo;
key.s.query_flags = qflags;
/* We are searching for a similar mesh state when we DO want to
* aggregate the state. Thus unique is set to NULL. (default when we
* desire aggregation).*/
key.unique = NULL;
key.s.client_info = cinfo;
result = (struct mesh_state*)rbtree_search(&mesh->all, &key);
return result;
}
/** remove mesh state callback */
int mesh_state_del_cb(struct mesh_state* s, mesh_cb_func_type cb, void* cb_arg)
{
struct mesh_cb* r, *prev = NULL;
r = s->cb_list;
while(r) {
if(r->cb == cb && r->cb_arg == cb_arg) {
/* Delete this entry. */
/* It was allocated in the s.region, so no free. */
if(prev) prev->next = r->next;
else s->cb_list = r->next;
return 1;
}
prev = r;
r = r->next;
}
return 0;
}
/* Data related to local alias stored in 'qinfo' (if any) is ephemeral
* and can be different for different original queries (even if the
* replaced query name is the same). So we need to make a deep copy
* and store the copy for each reply info. */
if(qinfo->local_alias) {
struct packed_rrset_data* d;
struct packed_rrset_data* dsrc;
r->local_alias = regional_alloc_zero(s->s.region,
sizeof(*qinfo->local_alias));
if(!r->local_alias)
return 0;
r->local_alias->rrset = regional_alloc_init(s->s.region,
qinfo->local_alias->rrset,
sizeof(*qinfo->local_alias->rrset));
if(!r->local_alias->rrset)
return 0;
dsrc = qinfo->local_alias->rrset->entry.data;
/* In the current implementation, a local alias must be
* a single CNAME RR (see worker_handle_request()). */
log_assert(!qinfo->local_alias->next && dsrc->count == 1 &&
qinfo->local_alias->rrset->rk.type ==
htons(LDNS_RR_TYPE_CNAME));
/* we should make a local copy for the owner name of
* the RRset */
r->local_alias->rrset->rk.dname_len =
qinfo->local_alias->rrset->rk.dname_len;
r->local_alias->rrset->rk.dname = regional_alloc_init(
s->s.region, qinfo->local_alias->rrset->rk.dname,
qinfo->local_alias->rrset->rk.dname_len);
if(!r->local_alias->rrset->rk.dname)
return 0;
/* the rrset is not packed, like in the cache, but it is
* individually allocated with an allocator from localzone. */
d = regional_alloc_zero(s->s.region, sizeof(*d));
if(!d)
return 0;
r->local_alias->rrset->entry.data = d;
if(!rrset_insert_rr(s->s.region, d, dsrc->rr_data[0],
dsrc->rr_len[0], dsrc->rr_ttl[0], "CNAME local alias"))
return 0;
} else
r->local_alias = NULL;
s->reply_list = r;
return 1;
}
/* Extract the query info and flags from 'mstate' into '*qinfop' and '*qflags'.
* Since this is only used for internal refetch of otherwise-expired answer,
* we simply ignore the rare failure mode when memory allocation fails. */
static void
mesh_copy_qinfo(struct mesh_state* mstate, struct query_info** qinfop,
uint16_t* qflags)
{
struct regional* region = mstate->s.env->scratch;
struct query_info* qinfo;
/**
* Continue processing the mesh state at another module.
* Handles module to modules transfer of control.
* Handles module finished.
* @param mesh: the mesh area.
* @param mstate: currently active mesh state.
* Deleted if finished, calls _done and _supers to
* send replies to clients and inform other mesh states.
* This in turn may create additional runnable mesh states.
* @param s: state at which the current module exited.
* @param ev: the event sent to the module.
* returned is the event to send to the next module.
* @return true if continue processing at the new module.
* false if not continued processing is needed.
*/
static int
mesh_continue(struct mesh_area* mesh, struct mesh_state* mstate,
enum module_ext_state s, enum module_ev* ev)
{
mstate->num_activated++;
if(mstate->num_activated > MESH_MAX_ACTIVATION) {
/* module is looping. Stop it. */
log_err("internal error: looping module (%s) stopped",
mesh->mods.mod[mstate->s.curmod]->name);
log_query_info(NO_VERBOSE, "pass error for qstate",
&mstate->s.qinfo);
s = module_error;
}
if(s == module_wait_module || s == module_restart_next) {
/* start next module */
mstate->s.curmod++;
if(mesh->mods.num == mstate->s.curmod) {
log_err("Cannot pass to next module; at last module");
log_query_info(VERB_QUERY, "pass error for qstate",
&mstate->s.qinfo);
mstate->s.curmod--;
return mesh_continue(mesh, mstate, module_error, ev);
}
if(s == module_restart_next) {
int curmod = mstate->s.curmod;
for(; mstate->s.curmod < mesh->mods.num;
mstate->s.curmod++) {
fptr_ok(fptr_whitelist_mod_clear(
mesh->mods.mod[mstate->s.curmod]->clear));
(*mesh->mods.mod[mstate->s.curmod]->clear)
(&mstate->s, mstate->s.curmod);
mstate->s.minfo[mstate->s.curmod] = NULL;
}
mstate->s.curmod = curmod;
}
*ev = module_event_pass;
return 1;
}
if(s == module_wait_subquery && mstate->sub_set.count == 0) {
log_err("module cannot wait for subquery, subquery list empty");
log_query_info(VERB_QUERY, "pass error for qstate",
&mstate->s.qinfo);
s = module_error;
}
if(s == module_error && mstate->s.return_rcode == LDNS_RCODE_NOERROR) {
/* error is bad, handle pass back up below */
mstate->s.return_rcode = LDNS_RCODE_SERVFAIL;
}
if(s == module_error) {
mesh_query_done(mstate);
mesh_walk_supers(mesh, mstate);
mesh_state_delete(&mstate->s);
return 0;
}
if(s == module_finished) {
if(mstate->s.curmod == 0) {
struct query_info* qinfo = NULL;
struct edns_option* opt_list = NULL;
struct sockaddr_storage addr;
uint16_t qflags;
int rpz_p = 0;
/* If the answer to the query needs to be refetched
* from an external DNS server, we'll need to schedule
* a prefetch after removing the current state, so
* we need to make a copy of the query info here. */
if(mstate->s.need_refetch) {
mesh_copy_qinfo(mstate, &qinfo, &qflags);
#ifdef CLIENT_SUBNET
/* Make also a copy of the ecs option if any */
if((ecs = edns_opt_list_find(
mstate->s.edns_opts_front_in,
mstate->s.env->cfg->client_subnet_opcode)) != NULL) {
(void)edns_opt_list_append(&opt_list,
ecs->opt_code, ecs->opt_len,
ecs->opt_data,
mstate->s.env->scratch);
}
#endif
rpz_p = mstate->s.rpz_passthru;
}
if(qinfo) {
mesh_state_delete(&mstate->s);
mesh_new_prefetch(mesh, qinfo, qflags, 0,
rpz_p,
addr.ss_family!=AF_UNSPEC?&addr:NULL,
opt_list);
} else {
mesh_state_delete(&mstate->s);
}
return 0;
}
/* pass along the locus of control */
mstate->s.curmod --;
*ev = module_event_moddone;
return 1;
}
return 0;
}
/* examine results */
mstate->s.reply = NULL;
regional_free_all(mstate->s.env->scratch);
s = mstate->s.ext_state[mstate->s.curmod];
verbose(VERB_ALGO, "mesh_run: %s module exit state is %s",
mesh->mods.mod[mstate->s.curmod]->name, strextstate(s));
e = NULL;
if(mesh_continue(mesh, mstate, s, &ev))
continue;
/* run more modules */
ev = module_event_pass;
if(mesh->run.count > 0) {
/* pop random element off the runnable tree */
mstate = (struct mesh_state*)mesh->run.root->key;
(void)rbtree_delete(&mesh->run, mstate);
} else mstate = NULL;
}
if(verbosity >= VERB_ALGO) {
mesh_stats(mesh, "mesh_run: end");
mesh_log_list(mesh);
}
}
void
mesh_log_list(struct mesh_area* mesh)
{
char buf[30];
struct mesh_state* m;
int num = 0;
RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
snprintf(buf, sizeof(buf), "%d%s%s%s%s%s%s mod%d %s%s",
num++, (m->s.is_priming)?"p":"", /* prime */
(m->s.is_valrec)?"v":"", /* prime */
(m->s.query_flags&BIT_RD)?"RD":"",
(m->s.query_flags&BIT_CD)?"CD":"",
(m->super_set.count==0)?"d":"", /* detached */
(m->sub_set.count!=0)?"c":"", /* children */
m->s.curmod, (m->reply_list)?"rep":"", /*hasreply*/
(m->cb_list)?"cb":"" /* callbacks */
);
log_query_info(VERB_ALGO, buf, &m->s.qinfo);
}
}
void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp,
struct mesh_state** lp)
{
/* insert as last element */
m->prev = *lp;
m->next = NULL;
if(*lp)
(*lp)->next = m;
else *fp = m;
*lp = m;
}
void mesh_state_remove_reply(struct mesh_area* mesh, struct mesh_state* m,
struct comm_point* cp)
{
struct mesh_reply* n, *prev = NULL;
n = m->reply_list;
/* when in mesh_cleanup, it sets the reply_list to NULL, so that
* there is no accounting twice */
if(!n) return; /* nothing to remove, also no accounting needed */
while(n) {
if(n->query_reply.c == cp) {
/* unlink it */
if(prev) prev->next = n->next;
else m->reply_list = n->next;
/* delete it, but allocated in m region */
log_assert(mesh->num_reply_addrs > 0);
mesh->num_reply_addrs--;
infra_wait_limit_dec(mesh->env->infra_cache,
&n->query_reply, mesh->env->cfg);
/* prev = prev; */
n = n->next;
continue;
}
prev = n;
n = n->next;
}
/* it was not detached (because it had a reply list), could be now */
if(!m->reply_list && !m->cb_list
&& m->super_set.count == 0) {
mesh->num_detached_states++;
}
/* if not replies any more in mstate, it is no longer a reply_state */
if(!m->reply_list && !m->cb_list) {
log_assert(mesh->num_reply_states > 0);
mesh->num_reply_states--;
}
}
/* xxx_deny actions mean dropping the reply, unless the original reply
* was redirected to response-ip data. */
if((actinfo->action == respip_deny ||
actinfo->action == respip_inform_deny) &&
*encode_repp == rep)
*encode_repp = NULL;
return 1;
}
void
mesh_serve_expired_callback(void* arg)
{
struct mesh_state* mstate = (struct mesh_state*) arg;
struct module_qstate* qstate = &mstate->s;
struct mesh_reply* r;
struct mesh_area* mesh = qstate->env->mesh;
struct dns_msg* msg;
struct mesh_cb* c;
struct mesh_reply* prev = NULL;
struct sldns_buffer* prev_buffer = NULL;
struct sldns_buffer* r_buffer = NULL;
struct reply_info* partial_rep = NULL;
struct ub_packed_rrset_key* alias_rrset = NULL;
struct reply_info* encode_rep = NULL;
struct respip_action_info actinfo;
struct query_info* lookup_qinfo = &qstate->qinfo;
struct query_info qinfo_tmp;
struct timeval tv = {0, 0};
int must_validate = (!(qstate->query_flags&BIT_CD)
|| qstate->env->cfg->ignore_cd) && qstate->env->need_to_validate;
int i = 0, for_count;
int is_expired;
if(!qstate->serve_expired_data) return;
verbose(VERB_ALGO, "Serve expired: Trying to reply with expired data");
comm_timer_delete(qstate->serve_expired_data->timer);
qstate->serve_expired_data->timer = NULL;
/* If is_drop or no_cache_lookup (modules that handle their own cache e.g.,
* subnetmod) ignore stale data from the main cache. */
if(qstate->no_cache_lookup || qstate->is_drop) {
verbose(VERB_ALGO,
"Serve expired: Not allowed to look into cache for stale");
return;
}
/* The following for is used instead of the `goto lookup_cache`
* like in the worker. This loop should get max 2 passes if we need to
* do any aliasing. */
for(for_count = 0; for_count < 2; for_count++) {
fptr_ok(fptr_whitelist_serve_expired_lookup(
qstate->serve_expired_data->get_cached_answer));
msg = (*qstate->serve_expired_data->get_cached_answer)(qstate,
lookup_qinfo, &is_expired);
if(!msg || (FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_NOERROR
&& FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_NXDOMAIN
&& FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_YXDOMAIN)) {
/* We don't care for cached failure answers at this
* stage. */
return;
}
/* Reset these in case we pass a second time from here. */
encode_rep = msg->rep;
memset(&actinfo, 0, sizeof(actinfo));
actinfo.action = respip_none;
alias_rrset = NULL;
if((mesh->use_response_ip || mesh->use_rpz) &&
!partial_rep && !apply_respip_action(qstate, &qstate->qinfo,
qstate->client_info, &actinfo, msg->rep, &alias_rrset, &encode_rep,
qstate->env->auth_zones)) {
return;
} else if(partial_rep &&
!respip_merge_cname(partial_rep, &qstate->qinfo, msg->rep,
qstate->client_info, must_validate, &encode_rep, qstate->region,
qstate->env->auth_zones, qstate->env->views,
qstate->env->respip_set)) {
return;
}
if(!encode_rep || alias_rrset) {
if(!encode_rep) {
/* Needs drop */
return;
} else {
/* A partial CNAME chain is found. */
partial_rep = encode_rep;
}
}
/* We've found a partial reply ending with an
* alias. Replace the lookup qinfo for the
* alias target and lookup the cache again to
* (possibly) complete the reply. As we're
* passing the "base" reply, there will be no
* more alias chasing. */
if(partial_rep) {
memset(&qinfo_tmp, 0, sizeof(qinfo_tmp));
get_cname_target(alias_rrset, &qinfo_tmp.qname,
&qinfo_tmp.qname_len);
if(!qinfo_tmp.qname) {
log_err("Serve expired: unexpected: invalid answer alias");
return;
}
qinfo_tmp.qtype = qstate->qinfo.qtype;
qinfo_tmp.qclass = qstate->qinfo.qclass;
lookup_qinfo = &qinfo_tmp;
continue;
}
break;
}
for(r = mstate->reply_list; r; r = r->next) {
struct timeval old;
timeval_subtract(&old, mstate->s.env->now_tv, &r->start_time);
if(mstate->s.env->cfg->discard_timeout != 0 &&
((int)old.tv_sec)*1000+((int)old.tv_usec)/1000 >
mstate->s.env->cfg->discard_timeout) {
/* Drop the reply, it is too old */
/* briefly set the reply_list to NULL, so that the
* tcp req info cleanup routine that calls the mesh
* to deregister the meshstate for it is not done
* because the list is NULL and also accounting is not
* done there, but instead we do that here. */
struct mesh_reply* reply_list = mstate->reply_list;
verbose(VERB_ALGO, "drop reply, it is older than discard-timeout");
infra_wait_limit_dec(mstate->s.env->infra_cache,
&r->query_reply, mstate->s.env->cfg);
mstate->reply_list = NULL;
if(r->query_reply.c->use_h2)
http2_stream_remove_mesh_state(r->h2_stream);
comm_point_drop_reply(&r->query_reply);
mstate->reply_list = reply_list;
mstate->s.env->mesh->num_queries_discard_timeout++;
continue;
}
i++;
tv = r->start_time;
/* If address info is returned, it means the action should be an
* 'inform' variant and the information should be logged. */
if(actinfo.addrinfo) {
respip_inform_print(&actinfo, r->qname,
qstate->qinfo.qtype, qstate->qinfo.qclass,
r->local_alias, &r->query_reply.client_addr,
r->query_reply.client_addrlen);
}
/* Add EDE Stale Answer (RCF8914). Ignore global ede as this is
* warning instead of an error */
if(r->edns.edns_present &&
qstate->env->cfg->ede_serve_expired &&
qstate->env->cfg->ede &&
is_expired) {
edns_opt_list_append_ede(&r->edns.opt_list_out,
mstate->s.region, LDNS_EDE_STALE_ANSWER, NULL);
}
while((c = mstate->cb_list) != NULL) {
/* take this cb off the list; so that the list can be
* changed, eg. by adds from the callback routine */
if(!mstate->reply_list && mstate->cb_list && !c->next) {
/* was a reply state, not anymore */
log_assert(qstate->env->mesh->num_reply_states > 0);
qstate->env->mesh->num_reply_states--;
}
mstate->cb_list = c->next;
if(!mstate->reply_list && !mstate->cb_list &&
mstate->super_set.count == 0)
qstate->env->mesh->num_detached_states++;
mesh_do_callback(mstate, LDNS_RCODE_NOERROR, msg->rep, c, &tv);
}
}
/* It was in the list and removed. */
log_assert(mesh->num_reply_addrs > 0);
mesh->num_reply_addrs--;
if(!s->reply_list && !s->cb_list) {
/* was a reply state, not anymore */
log_assert(mesh->num_reply_states > 0);
mesh->num_reply_states--;
}
if(!s->reply_list && !s->cb_list &&
s->super_set.count == 0) {
mesh->num_detached_states++;
}
}
