/*
* 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 REGENTS 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 "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"
/** subtract timers and the values do not overflow or become negative */
static void
timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start)
{
#ifndef S_SPLINT_S
time_t end_usec = end->tv_usec;;
d->tv_sec = end->tv_sec - start->tv_sec;
while(end_usec < start->tv_usec) {
end_usec += 1000000;
d->tv_sec--;
}
d->tv_usec = end_usec - start->tv_usec;
#endif
}
/** add timers and the values do not overflow or become negative */
static void
timeval_add(struct timeval* d, const struct timeval* add)
{
#ifndef S_SPLINT_S
d->tv_sec += add->tv_sec;
d->tv_usec += add->tv_usec;
while(d->tv_usec > 1000000 ) {
d->tv_usec -= 1000000;
d->tv_sec++;
}
#endif
}
/** divide sum of timers to get average */
static void
timeval_divide(struct timeval* avg, const struct timeval* sum, size_t d)
{
#ifndef S_SPLINT_S
size_t leftover;
if(d == 0) {
avg->tv_sec = 0;
avg->tv_usec = 0;
return;
}
avg->tv_sec = sum->tv_sec / d;
avg->tv_usec = sum->tv_usec / d;
/* handle fraction from seconds divide */
leftover = sum->tv_sec - avg->tv_sec*d;
avg->tv_usec += (leftover*1000000)/d;
#endif
}
/** histogram compare of time values */
static int
timeval_smaller(const struct timeval* x, const struct timeval* y)
{
#ifndef S_SPLINT_S
if(x->tv_sec < y->tv_sec)
return 1;
else if(x->tv_sec == y->tv_sec) {
if(x->tv_usec <= y->tv_usec)
return 1;
else return 0;
}
else return 0;
#endif
}
int
mesh_state_compare(const void* ap, const void* bp)
{
struct mesh_state* a = (struct mesh_state*)ap;
struct mesh_state* b = (struct mesh_state*)bp;
if(a->s.is_priming && !b->s.is_priming)
return -1;
if(!a->s.is_priming && b->s.is_priming)
return 1;
if((a->s.query_flags&BIT_RD) && !(b->s.query_flags&BIT_RD))
return -1;
if(!(a->s.query_flags&BIT_RD) && (b->s.query_flags&BIT_RD))
return 1;
if((a->s.query_flags&BIT_CD) && !(b->s.query_flags&BIT_CD))
return -1;
if(!(a->s.query_flags&BIT_CD) && (b->s.query_flags&BIT_CD))
return 1;
return query_info_compare(&a->s.qinfo, &b->s.qinfo);
}
int
mesh_state_ref_compare(const void* ap, const void* bp)
{
struct mesh_state_ref* a = (struct mesh_state_ref*)ap;
struct mesh_state_ref* b = (struct mesh_state_ref*)bp;
return mesh_state_compare(a->s, b->s);
}
struct mesh_area*
mesh_create(struct module_stack* stack, struct module_env* env)
{
struct mesh_area* mesh = calloc(1, sizeof(struct mesh_area));
if(!mesh) {
log_err("mesh area alloc: out of memory");
return NULL;
}
mesh->histogram = timehist_setup();
if(!mesh->histogram) {
free(mesh);
log_err("mesh area alloc: out of memory");
return NULL;
}
mesh->mods = *stack;
mesh->env = env;
rbtree_init(&mesh->run, &mesh_state_compare);
rbtree_init(&mesh->all, &mesh_state_compare);
mesh->num_reply_addrs = 0;
mesh->num_reply_states = 0;
mesh->num_detached_states = 0;
mesh->num_forever_states = 0;
mesh->stats_jostled = 0;
mesh->stats_dropped = 0;
mesh->max_reply_states = env->cfg->num_queries_per_thread;
mesh->max_forever_states = (mesh->max_reply_states+1)/2;
#ifndef S_SPLINT_S
mesh->jostle_max.tv_sec = (time_t)(env->cfg->jostle_time / 1000);
mesh->jostle_max.tv_usec = (time_t)((env->cfg->jostle_time % 1000)
*1000);
#endif
return mesh;
}
/** help mesh delete delete mesh states */
static void
mesh_delete_helper(rbnode_t* n, void* ATTR_UNUSED(arg))
{
struct mesh_state* mstate = (struct mesh_state*)n->key;
mesh_state_cleanup(mstate);
}
void
mesh_delete(struct mesh_area* mesh)
{
if(!mesh)
return;
/* free all query states */
traverse_postorder(&mesh->all, &mesh_delete_helper, NULL);
timehist_delete(mesh->histogram);
free(mesh);
}
int mesh_make_new_space(struct mesh_area* mesh)
{
struct mesh_state* m = mesh->jostle_last;
/* 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);
/* 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);
return 1;
}
}
/* no space for new item */
return 0;
}
void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
uint16_t qflags, struct edns_data* edns, struct comm_reply* rep,
uint16_t qid)
{
struct mesh_state* s = mesh_area_find(mesh, qinfo, qflags, 0);
int was_detached = 0;
int was_noreply = 0;
int added = 0;
/* does this create a new reply state? */
if(!s || s->list_select == mesh_no_list) {
if(!mesh_make_new_space(mesh)) {
verbose(VERB_ALGO, "Too many queries. dropping "
"incoming query.");
comm_point_drop_reply(rep);
mesh->stats_dropped ++;
return;
}
}
/* see if it already exists, if not, create one */
if(!s) {
struct rbnode_t* n;
s = mesh_state_create(mesh->env,qinfo, qflags, 0);
if(!s) {
log_err("mesh_state_create: out of memory; SERVFAIL");
error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
qinfo, qid, qflags, edns);
comm_point_send_reply(rep);
return;
}
n = rbtree_insert(&mesh->all, &s->node);
log_assert(n != NULL);
/* set detached (it is now) */
mesh->num_detached_states++;
added = 1;
}
if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
was_detached = 1;
if(!s->reply_list && !s->cb_list)
was_noreply = 1;
/* add reply to s */
if(!mesh_state_add_reply(s, edns, rep, qid, qflags, qinfo->qname)) {
log_err("mesh_new_client: out of memory; SERVFAIL");
error_encode(rep->c->buffer, LDNS_RCODE_SERVFAIL,
qinfo, qid, qflags, edns);
comm_point_send_reply(rep);
if(added)
mesh_state_delete(&s->s);
return;
}
/* 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);
}
int
mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo,
uint16_t qflags, struct edns_data* edns, ldns_buffer* buf,
uint16_t qid, mesh_cb_func_t cb, void* cb_arg)
{
struct mesh_state* s = mesh_area_find(mesh, qinfo, qflags, 0);
int was_detached = 0;
int was_noreply = 0;
int added = 0;
/* there are no limits on the number of callbacks */
/* see if it already exists, if not, create one */
if(!s) {
struct rbnode_t* n;
s = mesh_state_create(mesh->env,qinfo, qflags, 0);
if(!s) {
return 0;
}
n = rbtree_insert(&mesh->all, &s->node);
log_assert(n != NULL);
/* set detached (it is now) */
mesh->num_detached_states++;
added = 1;
}
if(!s->reply_list && !s->cb_list && s->super_set.count == 0)
was_detached = 1;
if(!s->reply_list && !s->cb_list)
was_noreply = 1;
/* add reply to s */
if(!mesh_state_add_cb(s, edns, buf, cb, cb_arg, qid, qflags)) {
if(added)
mesh_state_delete(&s->s);
return 0;
}
/* 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(added)
mesh_run(mesh, s, module_event_new, NULL);
return 1;
}
void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e,
struct comm_reply* reply, int what)
{
enum module_ev event = module_event_reply;
e->qstate->reply = reply;
if(what != NETEVENT_NOERROR) {
event = module_event_noreply;
if(what == NETEVENT_CAPSFAIL)
event = module_event_capsfail;
}
mesh_run(mesh, e->qstate->mesh_info, event, e);
}
struct mesh_state*
mesh_state_create(struct module_env* env, struct query_info* qinfo,
uint16_t qflags, int prime)
{
struct regional* region = alloc_reg_obtain(env->alloc);
struct mesh_state* mstate;
int i;
if(!region)
return NULL;
mstate = (struct mesh_state*)regional_alloc(region,
sizeof(struct mesh_state));
if(!mstate) {
alloc_reg_release(env->alloc, region);
return NULL;
}
memset(mstate, 0, sizeof(*mstate));
mstate->node = *RBTREE_NULL;
mstate->run_node = *RBTREE_NULL;
mstate->node.key = mstate;
mstate->run_node.key = mstate;
mstate->reply_list = NULL;
mstate->list_select = mesh_no_list;
mstate->replies_sent = 0;
rbtree_init(&mstate->super_set, &mesh_state_ref_compare);
rbtree_init(&mstate->sub_set, &mesh_state_ref_compare);
mstate->num_activated = 0;
/* init module qstate */
mstate->s.qinfo.qtype = qinfo->qtype;
mstate->s.qinfo.qclass = qinfo->qclass;
mstate->s.qinfo.qname_len = qinfo->qname_len;
mstate->s.qinfo.qname = regional_alloc_init(region, qinfo->qname,
qinfo->qname_len);
if(!mstate->s.qinfo.qname) {
alloc_reg_release(env->alloc, region);
return NULL;
}
/* remove all weird bits from qflags */
mstate->s.query_flags = (qflags & (BIT_RD|BIT_CD));
mstate->s.is_priming = prime;
mstate->s.reply = NULL;
mstate->s.region = region;
mstate->s.curmod = 0;
mstate->s.return_msg = 0;
mstate->s.return_rcode = LDNS_RCODE_NOERROR;
mstate->s.env = env;
mstate->s.mesh_info = mstate;
/* init modules */
for(i=0; i<env->mesh->mods.num; i++) {
mstate->s.minfo[i] = NULL;
mstate->s.ext_state[i] = module_state_initial;
}
return mstate;
}
void
mesh_state_cleanup(struct mesh_state* mstate)
{
struct mesh_area* mesh;
int i;
if(!mstate)
return;
/* drop unsent replies */
if(!mstate->replies_sent) {
struct mesh_reply* rep;
for(rep=mstate->reply_list; rep; rep=rep->next) {
comm_point_drop_reply(&rep->query_reply);
}
}
/* de-init modules */
mesh = mstate->s.env->mesh;
for(i=0; i<mesh->mods.num; i++) {
fptr_ok(fptr_whitelist_mod_clear(mesh->mods.mod[i]->clear));
(*mesh->mods.mod[i]->clear)(&mstate->s, i);
mstate->s.minfo[i] = NULL;
mstate->s.ext_state[i] = module_finished;
}
alloc_reg_release(mstate->s.env->alloc, mstate->s.region);
}
void
mesh_state_delete(struct module_qstate* qstate)
{
struct mesh_area* mesh;
struct mesh_state_ref* super, ref;
struct mesh_state* mstate;
if(!qstate)
return;
mstate = qstate->mesh_info;
mesh = mstate->s.env->mesh;
mesh_detach_subs(&mstate->s);
if(mstate->list_select == mesh_forever_list) {
mesh->num_forever_states --;
mesh_list_remove(mstate, &mesh->forever_first,
&mesh->forever_last);
} else if(mstate->list_select == mesh_jostle_list) {
mesh_list_remove(mstate, &mesh->jostle_first,
&mesh->jostle_last);
}
if(!mstate->reply_list && !mstate->cb_list
&& mstate->super_set.count == 0) {
log_assert(mesh->num_detached_states > 0);
mesh->num_detached_states--;
}
if(mstate->reply_list || mstate->cb_list) {
log_assert(mesh->num_reply_states > 0);
mesh->num_reply_states--;
}
ref.node.key = &ref;
ref.s = mstate;
RBTREE_FOR(super, struct mesh_state_ref*, &mstate->super_set) {
(void)rbtree_delete(&super->s->sub_set, &ref);
}
(void)rbtree_delete(&mesh->run, mstate);
(void)rbtree_delete(&mesh->all, mstate);
mesh_state_cleanup(mstate);
}
void mesh_detach_subs(struct module_qstate* qstate)
{
struct mesh_area* mesh = qstate->env->mesh;
struct mesh_state_ref* ref, lookup;
struct rbnode_t* n;
lookup.node.key = &lookup;
lookup.s = qstate->mesh_info;
RBTREE_FOR(ref, struct mesh_state_ref*, &qstate->mesh_info->sub_set) {
n = rbtree_delete(&ref->s->super_set, &lookup);
log_assert(n != NULL); /* must have been present */
if(!ref->s->reply_list && !ref->s->cb_list
&& ref->s->super_set.count == 0) {
mesh->num_detached_states++;
log_assert(mesh->num_detached_states +
mesh->num_reply_states <= mesh->all.count);
}
}
rbtree_init(&qstate->mesh_info->sub_set, &mesh_state_ref_compare);
}
int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
uint16_t qflags, int prime, struct module_qstate** newq)
{
/* find it, if not, create it */
struct mesh_area* mesh = qstate->env->mesh;
struct mesh_state* sub = mesh_area_find(mesh, qinfo, qflags, prime);
if(!sub) {
struct rbnode_t* n;
/* create a new one */
sub = mesh_state_create(qstate->env, qinfo, qflags, prime);
if(!sub) {
log_err("mesh_attach_sub: out of memory");
return 0;
}
n = 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 */
n = rbtree_insert(&mesh->run, &sub->run_node);
log_assert(n != NULL);
*newq = &sub->s;
} else
*newq = NULL;
if(!mesh_state_attachment(qstate->mesh_info, sub))
return 0;
if(!sub->reply_list && !sub->cb_list && 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)
{
struct rbnode_t* n;
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;
n = rbtree_insert(&sub->super_set, &superref->node);
log_assert(n != NULL);
n = rbtree_insert(&super->sub_set, &subref->node);
log_assert(n != NULL);
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
*/
static void
mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
struct mesh_cb* r)
{
int secure;
/* 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;
/* send the reply */
if(rcode) {
(*r->cb)(r->cb_arg, rcode, r->buf, sec_status_unchecked);
} else {
size_t udp_size = r->edns.udp_size;
ldns_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(!reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
r->qflags, r->buf, 0, 1,
m->s.env->scratch, udp_size, &r->edns,
(int)(r->edns.bits & EDNS_DO), secure))
{
(*r->cb)(r->cb_arg, LDNS_RCODE_SERVFAIL, r->buf,
sec_status_unchecked);
}
else (*r->cb)(r->cb_arg, LDNS_RCODE_NOERROR, r->buf,
rep->security);
}
m->s.env->mesh->num_reply_addrs--;
}
/**
* 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 prev: previous reply, already has its answer encoded in buffer.
*/
static void
mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
struct mesh_reply* r, struct mesh_reply* prev)
{
struct timeval end_time;
struct timeval duration;
int secure;
/* examine security status */
if(m->s.env->need_to_validate && !(r->qflags&BIT_CD) && rep &&
rep->security <= sec_status_bogus) {
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;
/* send the reply */
if(prev && prev->qflags == r->qflags &&
prev->edns.edns_present == r->edns.edns_present &&
prev->edns.bits == r->edns.bits &&
prev->edns.udp_size == r->edns.udp_size) {
/* if the previous reply is identical to this one, fix ID */
if(prev->query_reply.c->buffer != r->query_reply.c->buffer)
ldns_buffer_copy(r->query_reply.c->buffer,
prev->query_reply.c->buffer);
ldns_buffer_write_at(r->query_reply.c->buffer, 0,
&r->qid, sizeof(uint16_t));
ldns_buffer_write_at(r->query_reply.c->buffer, 12,
r->qname, m->s.qinfo.qname_len);
comm_point_send_reply(&r->query_reply);
} else if(rcode) {
m->s.qinfo.qname = r->qname;
error_encode(r->query_reply.c->buffer, rcode, &m->s.qinfo,
r->qid, r->qflags, &r->edns);
comm_point_send_reply(&r->query_reply);
} 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;
m->s.qinfo.qname = r->qname;
if(!reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
r->qflags, r->query_reply.c->buffer, 0, 1,
m->s.env->scratch, udp_size, &r->edns,
(int)(r->edns.bits & EDNS_DO), secure))
{
error_encode(r->query_reply.c->buffer,
LDNS_RCODE_SERVFAIL, &m->s.qinfo, r->qid,
r->qflags, &r->edns);
}
comm_point_send_reply(&r->query_reply);
}
/* account */
m->s.env->mesh->num_reply_addrs--;
end_time = *m->s.env->now_tv;
timeval_subtract(&duration, &end_time, &r->start_time);
verbose(VERB_ALGO, "query took %d.%6.6d sec",
(int)duration.tv_sec, (int)duration.tv_usec);
m->s.env->mesh->replies_sent++;
timeval_add(&m->s.env->mesh->replies_sum_wait, &duration);
timehist_insert(m->s.env->mesh->histogram, &duration);
if(m->s.env->cfg->stat_extended) {
uint16_t rc = FLAGS_GET_RCODE(ldns_buffer_read_u16_at(r->
query_reply.c->buffer, 2));
if(secure) m->s.env->mesh->ans_secure++;
m->s.env->mesh->ans_rcode[ rc ] ++;
if(rc == 0 && LDNS_ANCOUNT(ldns_buffer_begin(r->
query_reply.c->buffer)) == 0)
m->s.env->mesh->ans_nodata++;
}
}
void mesh_query_done(struct mesh_state* mstate)
{
struct mesh_reply* r;
struct mesh_reply* prev = NULL;
struct mesh_cb* c;
struct reply_info* rep = (mstate->s.return_msg?
mstate->s.return_msg->rep:NULL);
for(r = mstate->reply_list; r; r = r->next) {
mesh_send_reply(mstate, mstate->s.return_rcode, rep, r, prev);
prev = r;
}
mstate->replies_sent = 1;
for(c = mstate->cb_list; c; c = c->next) {
mesh_do_callback(mstate, mstate->s.return_rcode, rep, c);
}
}
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);
}
}
struct mesh_state* mesh_area_find(struct mesh_area* mesh,
struct query_info* qinfo, uint16_t qflags, int prime)
{
struct mesh_state key;
struct mesh_state* result;
key.node.key = &key;
key.s.is_priming = prime;
key.s.qinfo = *qinfo;
key.s.query_flags = qflags;
result = (struct mesh_state*)rbtree_search(&mesh->all, &key);
return result;
}
int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns,
ldns_buffer* buf, mesh_cb_func_t cb, void* cb_arg,
uint16_t qid, uint16_t qflags)
{
struct mesh_cb* r = regional_alloc(s->s.region,
sizeof(struct mesh_cb));
if(!r)
return 0;
r->buf = buf;
r->cb = cb;
r->cb_arg = cb_arg;
r->edns = *edns;
r->qid = qid;
r->qflags = qflags;
r->next = s->cb_list;
s->cb_list = r;
return 1;
}
int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns,
struct comm_reply* rep, uint16_t qid, uint16_t qflags, uint8_t* qname)
{
struct mesh_reply* r = regional_alloc(s->s.region,
sizeof(struct mesh_reply));
if(!r)
return 0;
r->query_reply = *rep;
r->edns = *edns;
r->qid = qid;
r->qflags = qflags;
r->start_time = *s->s.env->now_tv;
r->next = s->reply_list;
r->qname = regional_alloc_init(s->s.region, qname,
s->s.qinfo.qname_len);
if(!r->qname)
return 0;
s->reply_list = r;
return 1;
}
/**
* Continue processing the mesh state at another module.
* Handles module to modules tranfer 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 stopped");
log_query_info(VERB_QUERY, "pass error for qstate",
&mstate->s.qinfo);
s = module_error;
}
if(s == module_wait_module) {
/* 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);
}
*ev = module_event_pass;
return 1;
}
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 || s == module_finished) {
if(mstate->s.curmod == 0) {
mesh_query_done(mstate);
mesh_walk_supers(mesh, mstate);
mesh_state_delete(&mstate->s);
return 0;
}
/* pass along the locus of control */
mstate->s.curmod --;
*ev = module_event_moddone;
return 1;
}
return 0;
}
void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate,
enum module_ev ev, struct outbound_entry* e)
{
enum module_ext_state s;
verbose(VERB_ALGO, "mesh_run: start");
while(mstate) {
/* run the module */
fptr_ok(fptr_whitelist_mod_operate(
mesh->mods.mod[mstate->s.curmod]->operate));
(*mesh->mods.mod[mstate->s.curmod]->operate)
(&mstate->s, ev, mstate->s.curmod, e);
/* 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 mod%d %s%s",
num++, (m->s.is_priming)?"p":"", /* 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_stats(struct mesh_area* mesh, const char* str)
{
verbose(VERB_DETAIL, "%s %u recursion states (%u with reply, "
"%u detached), %u waiting replies, %u recursion replies "
"sent, %d replies dropped, %d states jostled out",
str, (unsigned)mesh->all.count,
(unsigned)mesh->num_reply_states,
(unsigned)mesh->num_detached_states,
(unsigned)mesh->num_reply_addrs,
(unsigned)mesh->replies_sent,
(unsigned)mesh->stats_dropped,
(unsigned)mesh->stats_jostled);
if(mesh->replies_sent > 0) {
struct timeval avg;
timeval_divide(&avg, &mesh->replies_sum_wait,
mesh->replies_sent);
log_info("average recursion processing time "
"%d.%6.6d sec", (int)avg.tv_sec, (int)avg.tv_usec);
log_info("histogram of recursion processing times");
timehist_log(mesh->histogram, "recursions");
}
}
void
mesh_stats_clear(struct mesh_area* mesh)
{
if(!mesh)
return;
mesh->replies_sent = 0;
mesh->replies_sum_wait.tv_sec = 0;
mesh->replies_sum_wait.tv_usec = 0;
mesh->stats_jostled = 0;
mesh->stats_dropped = 0;
timehist_clear(mesh->histogram);
mesh->ans_secure = 0;
mesh->ans_bogus = 0;
memset(&mesh->ans_rcode[0], 0, sizeof(size_t)*16);
mesh->ans_nodata = 0;
}
size_t
mesh_get_mem(struct mesh_area* mesh)
{
struct mesh_state* m;
size_t s = sizeof(*mesh) + sizeof(struct timehist) +
sizeof(struct th_buck)*mesh->histogram->num;
RBTREE_FOR(m, struct mesh_state*, &mesh->all) {
/* all, including m itself allocated in qstate region */
s += regional_get_mem(m->s.region);
}
return s;
}
/** helper recursive rbtree find routine */
static int
find_in_subsub(struct mesh_state* m, struct mesh_state* tofind)
{
struct mesh_state_ref* r;
RBTREE_FOR(r, struct mesh_state_ref*, &m->sub_set) {
if(r->s == tofind || find_in_subsub(r->s, tofind))
return 1;
}
return 0;
}
int
mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo,
uint16_t flags, int prime)
{
struct mesh_area* mesh = qstate->env->mesh;
struct mesh_state* cyc_m = qstate->mesh_info;
struct mesh_state* dep_m = mesh_area_find(mesh, qinfo, flags, prime);
if(!dep_m)
return 0;
if(dep_m == cyc_m || find_in_subsub(dep_m, cyc_m))
return 1;
return 0;
}
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_list_remove(struct mesh_state* m, struct mesh_state** fp,
struct mesh_state** lp)
{
if(m->next)
m->next->prev = m->prev;
else *lp = m->prev;
if(m->prev)
m->prev->next = m->next;
else *fp = m->next;
}