diff options
Diffstat (limited to 'src/ipcpd/normal/dht.c')
-rw-r--r-- | src/ipcpd/normal/dht.c | 2840 |
1 files changed, 0 insertions, 2840 deletions
diff --git a/src/ipcpd/normal/dht.c b/src/ipcpd/normal/dht.c deleted file mode 100644 index f24a2c51..00000000 --- a/src/ipcpd/normal/dht.c +++ /dev/null @@ -1,2840 +0,0 @@ -/* - * Ouroboros - Copyright (C) 2016 - 2019 - * - * Distributed Hash Table based on Kademlia - * - * Dimitri Staessens <dimitri.staessens@ugent.be> - * Sander Vrijders <sander.vrijders@ugent.be> - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public License - * version 2.1 as published by the Free Software Foundation. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., http://www.fsf.org/about/contact/. - */ - -#if defined(__linux__) || defined(__CYGWIN__) -#define _DEFAULT_SOURCE -#else -#define _POSIX_C_SOURCE 200112L -#endif - -#include "config.h" - -#define DHT "dht" -#define OUROBOROS_PREFIX DHT - -#include <ouroboros/hash.h> -#include <ouroboros/ipcp-dev.h> -#include <ouroboros/bitmap.h> -#include <ouroboros/errno.h> -#include <ouroboros/logs.h> -#include <ouroboros/list.h> -#include <ouroboros/notifier.h> -#include <ouroboros/random.h> -#include <ouroboros/time_utils.h> -#include <ouroboros/tpm.h> -#include <ouroboros/utils.h> - -#include "connmgr.h" -#include "dht.h" -#include "dt.h" - -#include <pthread.h> -#include <stdlib.h> -#include <string.h> -#include <assert.h> -#include <inttypes.h> -#include <limits.h> - -#include "kademlia.pb-c.h" -typedef KadMsg kad_msg_t; -typedef KadContactMsg kad_contact_msg_t; - -#ifndef CLOCK_REALTIME_COARSE -#define CLOCK_REALTIME_COARSE CLOCK_REALTIME -#endif - -#define DHT_MAX_REQS 2048 /* KAD recommends rnd(), bmp can be changed. */ -#define KAD_ALPHA 3 /* Parallel factor, proven optimal value. */ -#define KAD_K 8 /* Replication factor, MDHT value. */ -#define KAD_T_REPL 900 /* Replication time, tied to k. MDHT value. */ -#define KAD_T_REFR 900 /* Refresh time stale bucket, MDHT value. */ -#define KAD_T_JOIN 8 /* Response time to wait for a join. */ -#define KAD_T_RESP 5 /* Response time to wait for a response. */ -#define KAD_R_PING 2 /* Ping retries before declaring peer dead. */ -#define KAD_QUEER 15 /* Time to declare peer questionable. */ -#define KAD_BETA 8 /* Bucket split factor, must be 1, 2, 4 or 8. */ -#define KAD_RESP_RETR 6 /* Number of retries on sending a response. */ -#define KAD_JOIN_RETR 8 /* Number of retries sending a join. */ -#define KAD_JOIN_INTV 1 /* Time (seconds) between join retries. */ -#define HANDLE_TIMEO 1000 /* Timeout for dht_handle_packet tpm check (ms) */ -#define DHT_RETR_ADDR 1 /* Number of addresses to return on retrieve */ - -enum dht_state { - DHT_INIT = 0, - DHT_SHUTDOWN, - DHT_JOINING, - DHT_RUNNING, -}; - -enum kad_code { - KAD_JOIN = 0, - KAD_FIND_NODE, - KAD_FIND_VALUE, - /* Messages without a response below. */ - KAD_STORE, - KAD_RESPONSE -}; - -enum kad_req_state { - REQ_NULL = 0, - REQ_INIT, - REQ_PENDING, - REQ_RESPONSE, - REQ_DONE, - REQ_DESTROY -}; - -enum lookup_state { - LU_NULL = 0, - LU_INIT, - LU_PENDING, - LU_UPDATE, - LU_COMPLETE, - LU_DESTROY -}; - -struct kad_req { - struct list_head next; - - uint32_t cookie; - enum kad_code code; - uint8_t * key; - uint64_t addr; - - enum kad_req_state state; - pthread_cond_t cond; - pthread_mutex_t lock; - - time_t t_exp; -}; - -struct cookie_el { - struct list_head next; - - uint32_t cookie; -}; - -struct lookup { - struct list_head next; - - struct list_head cookies; - - uint8_t * key; - - struct list_head contacts; - size_t n_contacts; - - uint64_t * addrs; - size_t n_addrs; - - enum lookup_state state; - pthread_cond_t cond; - pthread_mutex_t lock; -}; - -struct val { - struct list_head next; - - uint64_t addr; - - time_t t_exp; - time_t t_rep; -}; - -struct ref_entry { - struct list_head next; - - uint8_t * key; - - time_t t_rep; -}; - -struct dht_entry { - struct list_head next; - - uint8_t * key; - size_t n_vals; - struct list_head vals; -}; - -struct contact { - struct list_head next; - - uint8_t * id; - uint64_t addr; - - size_t fails; - time_t t_seen; -}; - -struct bucket { - struct list_head contacts; - size_t n_contacts; - - struct list_head alts; - size_t n_alts; - - time_t t_refr; - - size_t depth; - uint8_t mask; - - struct bucket * parent; - struct bucket * children[1L << KAD_BETA]; -}; - -struct cmd { - struct list_head next; - - struct shm_du_buff * sdb; -}; - -struct dht { - size_t alpha; - size_t b; - size_t k; - - time_t t_expire; - time_t t_refresh; - time_t t_replic; - time_t t_repub; - - uint8_t * id; - uint64_t addr; - - struct bucket * buckets; - - struct list_head entries; - - struct list_head refs; - - struct list_head lookups; - - struct list_head requests; - struct bmp * cookies; - - enum dht_state state; - struct list_head cmds; - pthread_cond_t cond; - pthread_mutex_t mtx; - - pthread_rwlock_t lock; - - int fd; - - struct tpm * tpm; - - pthread_t worker; -}; - -struct join_info { - struct dht * dht; - uint64_t addr; -}; - -struct packet_info { - struct dht * dht; - struct shm_du_buff * sdb; -}; - -static uint8_t * dht_dup_key(const uint8_t * key, - size_t len) -{ - uint8_t * dup; - - dup = malloc(sizeof(*dup) * len); - if (dup == NULL) - return NULL; - - memcpy(dup, key, len); - - return dup; -} - -static enum dht_state dht_get_state(struct dht * dht) -{ - enum dht_state state; - - pthread_mutex_lock(&dht->mtx); - - state = dht->state; - - pthread_mutex_unlock(&dht->mtx); - - return state; -} - -static int dht_set_state(struct dht * dht, - enum dht_state state) -{ - pthread_mutex_lock(&dht->mtx); - - if (state == DHT_JOINING && dht->state != DHT_INIT) { - pthread_mutex_unlock(&dht->mtx); - return -1; - } - - dht->state = state; - - pthread_cond_broadcast(&dht->cond); - - pthread_mutex_unlock(&dht->mtx); - - return 0; -} - -int dht_wait_running(struct dht * dht) -{ - int ret = 0; - - pthread_mutex_lock(&dht->mtx); - - pthread_cleanup_push((void *)(void *) pthread_mutex_unlock, - &dht->mtx); - - while (dht->state == DHT_JOINING) - pthread_cond_wait(&dht->cond, &dht->mtx); - - if (dht->state != DHT_RUNNING) - ret = -1; - - pthread_cleanup_pop(true); - - return ret; -} - -static uint8_t * create_id(size_t len) -{ - uint8_t * id; - - id = malloc(len); - if (id == NULL) - return NULL; - - if (random_buffer(id, len) < 0) { - free(id); - return NULL; - } - - return id; -} - -static void kad_req_create(struct dht * dht, - kad_msg_t * msg, - uint64_t addr) -{ - struct kad_req * req; - pthread_condattr_t cattr; - struct timespec t; - size_t b; - - req = malloc(sizeof(*req)); - if (req == NULL) - return; - - list_head_init(&req->next); - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - - req->t_exp = t.tv_sec + KAD_T_RESP; - req->addr = addr; - req->state = REQ_INIT; - req->cookie = msg->cookie; - req->code = msg->code; - req->key = NULL; - - pthread_rwlock_rdlock(&dht->lock); - b = dht->b; - pthread_rwlock_unlock(&dht->lock); - - if (msg->has_key) { - req->key = dht_dup_key(msg->key.data, b); - if (req->key == NULL) { - free(req); - return; - } - } - - if (pthread_mutex_init(&req->lock, NULL)) { - free(req->key); - free(req); - return; - } - - pthread_condattr_init(&cattr); -#ifndef __APPLE__ - pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK); -#endif - - if (pthread_cond_init(&req->cond, &cattr)) { - pthread_condattr_destroy(&cattr); - pthread_mutex_destroy(&req->lock); - free(req->key); - free(req); - return; - } - - pthread_condattr_destroy(&cattr); - - pthread_rwlock_wrlock(&dht->lock); - - list_add(&req->next, &dht->requests); - - pthread_rwlock_unlock(&dht->lock); -} - -static void cancel_req_destroy(void * o) -{ - struct kad_req * req = (struct kad_req *) o; - - pthread_mutex_unlock(&req->lock); - - pthread_cond_destroy(&req->cond); - pthread_mutex_destroy(&req->lock); - - if (req->key != NULL) - free(req->key); - - free(req); -} - -static void kad_req_destroy(struct kad_req * req) -{ - assert(req); - - pthread_mutex_lock(&req->lock); - - switch (req->state) { - case REQ_DESTROY: - pthread_mutex_unlock(&req->lock); - return; - case REQ_PENDING: - req->state = REQ_DESTROY; - pthread_cond_signal(&req->cond); - break; - case REQ_INIT: - case REQ_DONE: - req->state = REQ_NULL; - break; - case REQ_RESPONSE: - case REQ_NULL: - default: - break; - } - - pthread_cleanup_push(cancel_req_destroy, req); - - while (req->state != REQ_NULL && req->state != REQ_DONE) - pthread_cond_wait(&req->cond, &req->lock); - - pthread_cleanup_pop(true); -} - -static int kad_req_wait(struct kad_req * req, - time_t t) -{ - struct timespec timeo = {t, 0}; - struct timespec abs; - int ret = 0; - - assert(req); - - clock_gettime(PTHREAD_COND_CLOCK, &abs); - - ts_add(&abs, &timeo, &abs); - - pthread_mutex_lock(&req->lock); - - req->state = REQ_PENDING; - - pthread_cleanup_push((void *)(void *) pthread_mutex_unlock, - &req->lock); - - while (req->state == REQ_PENDING && ret != -ETIMEDOUT) - ret = -pthread_cond_timedwait(&req->cond, &req->lock, &abs); - - switch(req->state) { - case REQ_DESTROY: - ret = -1; - req->state = REQ_NULL; - pthread_cond_signal(&req->cond); - break; - case REQ_PENDING: /* ETIMEDOUT */ - case REQ_RESPONSE: - req->state = REQ_DONE; - pthread_cond_broadcast(&req->cond); - break; - default: - break; - } - - pthread_cleanup_pop(true); - - return ret; -} - -static void kad_req_respond(struct kad_req * req) -{ - pthread_mutex_lock(&req->lock); - - req->state = REQ_RESPONSE; - pthread_cond_signal(&req->cond); - - pthread_mutex_unlock(&req->lock); -} - -static struct contact * contact_create(const uint8_t * id, - size_t len, - uint64_t addr) -{ - struct contact * c; - struct timespec t; - - c = malloc(sizeof(*c)); - if (c == NULL) - return NULL; - - list_head_init(&c->next); - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - - c->addr = addr; - c->fails = 0; - c->t_seen = t.tv_sec; - c->id = dht_dup_key(id, len); - if (c->id == NULL) { - free(c); - return NULL; - } - - return c; -} - -static void contact_destroy(struct contact * c) -{ - if (c != NULL) - free(c->id); - - free(c); -} - -static struct bucket * iter_bucket(struct bucket * b, - const uint8_t * id) -{ - uint8_t byte; - uint8_t mask; - - assert(b); - - if (b->children[0] == NULL) - return b; - - byte = id[(b->depth * KAD_BETA) / CHAR_BIT]; - - mask = ((1L << KAD_BETA) - 1) & 0xFF; - - byte >>= (CHAR_BIT - KAD_BETA) - - (((b->depth) * KAD_BETA) & (CHAR_BIT - 1)); - - return iter_bucket(b->children[(byte & mask)], id); -} - -static struct bucket * dht_get_bucket(struct dht * dht, - const uint8_t * id) -{ - assert(dht->buckets); - - return iter_bucket(dht->buckets, id); -} - -/* - * If someone builds a network where the n (n > k) closest nodes all - * have IDs starting with the same 64 bits: by all means, change this. - */ -static uint64_t dist(const uint8_t * src, - const uint8_t * dst) -{ - return betoh64(*((uint64_t *) src) ^ *((uint64_t *) dst)); -} - -static size_t list_add_sorted(struct list_head * l, - struct contact * c, - const uint8_t * key) -{ - struct list_head * p; - - assert(l); - assert(c); - assert(key); - assert(c->id); - - list_for_each(p, l) { - struct contact * e = list_entry(p, struct contact, next); - if (dist(c->id, key) > dist(e->id, key)) - break; - } - - list_add_tail(&c->next, p); - - return 1; -} - -static size_t dht_contact_list(struct dht * dht, - struct list_head * l, - const uint8_t * key) -{ - struct list_head * p; - struct bucket * b; - size_t len = 0; - size_t i; - struct timespec t; - - assert(l); - assert(dht); - assert(key); - assert(list_is_empty(l)); - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - - b = dht_get_bucket(dht, key); - if (b == NULL) - return 0; - - b->t_refr = t.tv_sec + KAD_T_REFR; - - if (b->n_contacts == dht->k || b->parent == NULL) { - list_for_each(p, &b->contacts) { - struct contact * c; - c = list_entry(p, struct contact, next); - c = contact_create(c->id, dht->b, c->addr); - if (list_add_sorted(l, c, key) == 1) - if (++len == dht->k) - break; - } - } else { - struct bucket * d = b->parent; - for (i = 0; i < (1L << KAD_BETA) && len < dht->k; ++i) { - list_for_each(p, &d->children[i]->contacts) { - struct contact * c; - c = list_entry(p, struct contact, next); - c = contact_create(c->id, dht->b, c->addr); - if (c == NULL) - continue; - if (list_add_sorted(l, c, key) == 1) - if (++len == dht->k) - break; - } - } - } - - assert(len == dht->k || b->parent == NULL); - - return len; -} - -static struct lookup * lookup_create(struct dht * dht, - const uint8_t * id) -{ - struct lookup * lu; - pthread_condattr_t cattr; - - assert(dht); - assert(id); - - lu = malloc(sizeof(*lu)); - if (lu == NULL) - goto fail_malloc; - - list_head_init(&lu->contacts); - list_head_init(&lu->cookies); - - lu->state = LU_INIT; - lu->addrs = NULL; - lu->n_addrs = 0; - lu->key = dht_dup_key(id, dht->b); - if (lu->key == NULL) - goto fail_id; - - if (pthread_mutex_init(&lu->lock, NULL)) - goto fail_mutex; - - pthread_condattr_init(&cattr); -#ifndef __APPLE__ - pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK); -#endif - - if (pthread_cond_init(&lu->cond, &cattr)) - goto fail_cond; - - pthread_condattr_destroy(&cattr); - - pthread_rwlock_wrlock(&dht->lock); - - list_add(&lu->next, &dht->lookups); - - lu->n_contacts = dht_contact_list(dht, &lu->contacts, id); - - pthread_rwlock_unlock(&dht->lock); - - return lu; - - fail_cond: - pthread_condattr_destroy(&cattr); - pthread_mutex_destroy(&lu->lock); - fail_mutex: - free(lu->key); - fail_id: - free(lu); - fail_malloc: - return NULL; -} - -static void cancel_lookup_destroy(void * o) -{ - struct lookup * lu; - struct list_head * p; - struct list_head * h; - - lu = (struct lookup *) o; - - if (lu->key != NULL) - free(lu->key); - if (lu->addrs != NULL) - free(lu->addrs); - - list_for_each_safe(p, h, &lu->contacts) { - struct contact * c = list_entry(p, struct contact, next); - list_del(&c->next); - contact_destroy(c); - } - - list_for_each_safe(p, h, &lu->cookies) { - struct cookie_el * c = list_entry(p, struct cookie_el, next); - list_del(&c->next); - free(c); - } - - pthread_mutex_unlock(&lu->lock); - - pthread_mutex_destroy(&lu->lock); - - free(lu); -} - -static void lookup_destroy(struct lookup * lu) -{ - assert(lu); - - pthread_mutex_lock(&lu->lock); - - switch (lu->state) { - case LU_DESTROY: - pthread_mutex_unlock(&lu->lock); - return; - case LU_PENDING: - lu->state = LU_DESTROY; - pthread_cond_broadcast(&lu->cond); - break; - case LU_INIT: - case LU_UPDATE: - case LU_COMPLETE: - lu->state = LU_NULL; - break; - case LU_NULL: - default: - break; - } - - pthread_cleanup_push(cancel_lookup_destroy, lu); - - while (lu->state != LU_NULL) - pthread_cond_wait(&lu->cond, &lu->lock); - - pthread_cleanup_pop(true); -} - -static void lookup_update(struct dht * dht, - struct lookup * lu, - kad_msg_t * msg) -{ - struct list_head * p = NULL; - struct list_head * h; - struct contact * c = NULL; - size_t n; - size_t pos = 0; - bool mod = false; - - assert(lu); - assert(msg); - - if (dht_get_state(dht) != DHT_RUNNING) - return; - - pthread_mutex_lock(&lu->lock); - - list_for_each_safe(p, h, &lu->cookies) { - struct cookie_el * e = list_entry(p, struct cookie_el, next); - if (e->cookie == msg->cookie) { - list_del(&e->next); - free(e); - break; - } - } - - if (lu->state == LU_COMPLETE) { - pthread_mutex_unlock(&lu->lock); - return; - } - - if (msg->n_addrs > 0) { - if (lu->addrs == NULL) { - lu->addrs = malloc(sizeof(*lu->addrs) * msg->n_addrs); - for (n = 0; n < msg->n_addrs; ++n) - lu->addrs[n] = msg->addrs[n]; - lu->n_addrs = msg->n_addrs; - } - - lu->state = LU_COMPLETE; - pthread_cond_broadcast(&lu->cond); - pthread_mutex_unlock(&lu->lock); - return; - } - - pthread_cleanup_push((void *)(void *) pthread_mutex_unlock, - &lu->lock); - - while (lu->state == LU_INIT) { - pthread_rwlock_unlock(&dht->lock); - pthread_cond_wait(&lu->cond, &lu->lock); - pthread_rwlock_rdlock(&dht->lock); - } - - pthread_cleanup_pop(false); - - for (n = 0; n < msg->n_contacts; ++n) { - c = contact_create(msg->contacts[n]->id.data, - dht->b, msg->contacts[n]->addr); - if (c == NULL) - continue; - - pos = 0; - - list_for_each(p, &lu->contacts) { - struct contact * e; - e = list_entry(p, struct contact, next); - if (!memcmp(e->id, c->id, dht->b)) { - contact_destroy(c); - c = NULL; - break; - } - - if (dist(c->id, lu->key) > dist(e->id, lu->key)) - break; - - pos++; - } - - if (c == NULL) - continue; - - if (lu->n_contacts < dht->k) { - list_add_tail(&c->next, p); - ++lu->n_contacts; - mod = true; - } else if (pos == dht->k) { - contact_destroy(c); - } else { - struct contact * d; - list_add_tail(&c->next, p); - d = list_last_entry(&lu->contacts, - struct contact, next); - list_del(&d->next); - assert(lu->contacts.prv != &d->next); - contact_destroy(d); - mod = true; - } - } - - if (list_is_empty(&lu->cookies) && !mod) - lu->state = LU_COMPLETE; - else - lu->state = LU_UPDATE; - - pthread_cond_broadcast(&lu->cond); - pthread_mutex_unlock(&lu->lock); - return; -} - -static ssize_t lookup_get_addrs(struct lookup * lu, - uint64_t * addrs) -{ - ssize_t n; - - assert(lu); - - pthread_mutex_lock(&lu->lock); - - for (n = 0; (size_t) n < lu->n_addrs; ++n) - addrs[n] = lu->addrs[n]; - - assert((size_t) n == lu->n_addrs); - - pthread_mutex_unlock(&lu->lock); - - return n; -} - -static ssize_t lookup_contact_addrs(struct lookup * lu, - uint64_t * addrs) -{ - struct list_head * p; - ssize_t n = 0; - - assert(lu); - assert(addrs); - - pthread_mutex_lock(&lu->lock); - - list_for_each(p, &lu->contacts) { - struct contact * c = list_entry(p, struct contact, next); - addrs[n] = c->addr; - n++; - } - - pthread_mutex_unlock(&lu->lock); - - return n; -} - -static void lookup_new_addrs(struct lookup * lu, - uint64_t * addrs) -{ - struct list_head * p; - size_t n = 0; - - assert(lu); - assert(addrs); - - pthread_mutex_lock(&lu->lock); - - /* Uses fails to check if the contact has been contacted. */ - list_for_each(p, &lu->contacts) { - struct contact * c = list_entry(p, struct contact, next); - if (c->fails == 0) { - c->fails = 1; - addrs[n] = c->addr; - n++; - } - - if (n == KAD_ALPHA) - break; - } - - assert(n <= KAD_ALPHA); - - addrs[n] = 0; - - pthread_mutex_unlock(&lu->lock); -} - -static void lookup_set_state(struct lookup * lu, - enum lookup_state state) -{ - pthread_mutex_lock(&lu->lock); - - lu->state = state; - pthread_cond_broadcast(&lu->cond); - - pthread_mutex_unlock(&lu->lock); -} - -static void cleanup_wait(void * o) -{ - struct lookup * lu = (struct lookup *) o; - lu->state = LU_NULL; - pthread_mutex_unlock(&lu->lock); - lookup_destroy(lu); -} - -static enum lookup_state lookup_wait(struct lookup * lu) -{ - struct timespec timeo = {KAD_T_RESP, 0}; - struct timespec abs; - enum lookup_state state; - int ret = 0; - - clock_gettime(PTHREAD_COND_CLOCK, &abs); - - ts_add(&abs, &timeo, &abs); - - pthread_mutex_lock(&lu->lock); - - if (lu->state == LU_INIT || lu->state == LU_UPDATE) - lu->state = LU_PENDING; - - pthread_cleanup_push(cleanup_wait, lu); - - while (lu->state == LU_PENDING && ret != -ETIMEDOUT) - ret = -pthread_cond_timedwait(&lu->cond, &lu->lock, &abs); - - pthread_cleanup_pop(false); - - if (ret == -ETIMEDOUT) - lu->state = LU_COMPLETE; - - state = lu->state; - - pthread_mutex_unlock(&lu->lock); - - return state; -} - -static struct kad_req * dht_find_request(struct dht * dht, - kad_msg_t * msg) -{ - struct list_head * p; - - assert(dht); - assert(msg); - - list_for_each(p, &dht->requests) { - struct kad_req * r = list_entry(p, struct kad_req, next); - if (r->cookie == msg->cookie) - return r; - } - - return NULL; -} - -static struct lookup * dht_find_lookup(struct dht * dht, - uint32_t cookie) -{ - struct list_head * p; - struct list_head * p2; - struct list_head * h2; - - assert(dht); - assert(cookie > 0); - - list_for_each(p, &dht->lookups) { - struct lookup * l = list_entry(p, struct lookup, next); - pthread_mutex_lock(&l->lock); - list_for_each_safe(p2, h2, &l->cookies) { - struct cookie_el * e; - e = list_entry(p2, struct cookie_el, next); - if (e->cookie == cookie) { - list_del(&e->next); - free(e); - pthread_mutex_unlock(&l->lock); - return l; - } - } - pthread_mutex_unlock(&l->lock); - } - - return NULL; -} - -static struct val * val_create(uint64_t addr, - time_t exp) -{ - struct val * v; - struct timespec t; - - v = malloc(sizeof(*v)); - if (v == NULL) - return NULL; - - list_head_init(&v->next); - v->addr = addr; - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - - v->t_exp = t.tv_sec + exp; - v->t_rep = t.tv_sec + KAD_T_REPL; - - return v; -} - -static void val_destroy(struct val * v) -{ - assert(v); - - free(v); -} - -static struct ref_entry * ref_entry_create(struct dht * dht, - const uint8_t * key) -{ - struct ref_entry * e; - struct timespec t; - - assert(dht); - assert(key); - - e = malloc(sizeof(*e)); - if (e == NULL) - return NULL; - - e->key = dht_dup_key(key, dht->b); - if (e->key == NULL) { - free(e); - return NULL; - } - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - - e->t_rep = t.tv_sec + dht->t_repub; - - return e; -} - -static void ref_entry_destroy(struct ref_entry * e) -{ - free(e->key); - free(e); -} - -static struct dht_entry * dht_entry_create(struct dht * dht, - const uint8_t * key) -{ - struct dht_entry * e; - - assert(dht); - assert(key); - - e = malloc(sizeof(*e)); - if (e == NULL) - return NULL; - - list_head_init(&e->next); - list_head_init(&e->vals); - - e->n_vals = 0; - - e->key = dht_dup_key(key, dht->b); - if (e->key == NULL) { - free(e); - return NULL; - } - - return e; -} - -static void dht_entry_destroy(struct dht_entry * e) -{ - struct list_head * p; - struct list_head * h; - - assert(e); - - list_for_each_safe(p, h, &e->vals) { - struct val * v = list_entry(p, struct val, next); - list_del(&v->next); - val_destroy(v); - } - - free(e->key); - - free(e); -} - -static int dht_entry_add_addr(struct dht_entry * e, - uint64_t addr, - time_t exp) -{ - struct list_head * p; - struct val * val; - struct timespec t; - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - - list_for_each(p, &e->vals) { - struct val * v = list_entry(p, struct val, next); - if (v->addr == addr) { - if (v->t_exp < t.tv_sec + exp) { - v->t_exp = t.tv_sec + exp; - v->t_rep = t.tv_sec + KAD_T_REPL; - } - - return 0; - } - } - - val = val_create(addr, exp); - if (val == NULL) - return -ENOMEM; - - list_add(&val->next, &e->vals); - ++e->n_vals; - - return 0; -} - - -static void dht_entry_del_addr(struct dht_entry * e, - uint64_t addr) -{ - struct list_head * p; - struct list_head * h; - - assert(e); - - list_for_each_safe(p, h, &e->vals) { - struct val * v = list_entry(p, struct val, next); - if (v->addr == addr) { - list_del(&v->next); - val_destroy(v); - --e->n_vals; - } - } - - if (e->n_vals == 0) { - list_del(&e->next); - dht_entry_destroy(e); - } -} - -static uint64_t dht_entry_get_addr(struct dht * dht, - struct dht_entry * e) -{ - struct list_head * p; - - assert(e); - assert(!list_is_empty(&e->vals)); - - list_for_each(p, &e->vals) { - struct val * v = list_entry(p, struct val, next); - if (v->addr != dht->addr) - return v->addr; - } - - return 0; -} - -/* Forward declaration. */ -static struct lookup * kad_lookup(struct dht * dht, - const uint8_t * key, - enum kad_code code); - - -/* Build a refresh list. */ -static void bucket_refresh(struct dht * dht, - struct bucket * b, - time_t t, - struct list_head * r) -{ - size_t i; - - if (*b->children != NULL) - for (i = 0; i < (1L << KAD_BETA); ++i) - bucket_refresh(dht, b->children[i], t, r); - - if (b->n_contacts == 0) - return; - - if (t > b->t_refr) { - struct contact * c; - struct contact * d; - c = list_first_entry(&b->contacts, struct contact, next); - d = contact_create(c->id, dht->b, c->addr); - if (c != NULL) - list_add(&d->next, r); - return; - } -} - - -static struct bucket * bucket_create(void) -{ - struct bucket * b; - struct timespec t; - size_t i; - - b = malloc(sizeof(*b)); - if (b == NULL) - return NULL; - - list_head_init(&b->contacts); - b->n_contacts = 0; - - list_head_init(&b->alts); - b->n_alts = 0; - - clock_gettime(CLOCK_REALTIME_COARSE, &t); - b->t_refr = t.tv_sec + KAD_T_REFR; - - for (i = 0; i < (1L << KAD_BETA); ++i) - b->children[i] = NULL; - - b->parent = NULL; - b->depth = 0; - - return b; -} - -static void bucket_destroy(struct bucket * b) -{ - struct list_head * p; - struct list_head * h; - size_t i; - - assert(b); - - for (i = 0; i < (1L << KAD_BETA); ++i) - if (b->children[i] != NULL) - bucket_destroy(b->children[i]); - - list_for_each_safe(p, h, &b->contacts) { - struct contact * c = list_entry(p, struct contact, next); - list_del(&c->next); - contact_destroy(c); - --b->n_contacts; - } - - list_for_each_safe(p, h, &b->alts) { - struct contact * c = list_entry(p, struct contact, next); - list_del(&c->next); - contact_destroy(c); - --b->n_contacts; - } - - free(b); -} - -static bool bucket_has_id(struct bucket * b, - const uint8_t * id) -{ - uint8_t mask; - uint8_t byte; - - if (b->depth == 0) - return true; - - byte = id[(b->depth * KAD_BETA) / CHAR_BIT]; - - mask = ((1L << KAD_BETA) - 1) & 0xFF; - - byte >>= (CHAR_BIT - KAD_BETA) - - (((b->depth - 1) * KAD_BETA) & (CHAR_BIT - 1)); - - return ((byte & mask) == b->mask); -} - -static int split_bucket(struct bucket * b) -{ - struct list_head * p; - struct list_head * h; - uint8_t mask = 0; - size_t i; - size_t c; - - assert(b); - assert(b->n_alts == 0); - assert(b->n_contacts); - assert(b->children[0] == NULL); - - c = b->n_contacts; - - for (i = 0; i < (1L << KAD_BETA); ++i) { - b->children[i] = bucket_create(); - if (b->children[i] == NULL) { - size_t j; - for (j = 0; j < i; ++j) - bucket_destroy(b->children[j]); - return -1; - } - - b->children[i]->depth = b->depth + 1; - b->children[i]->mask = mask; - b->children[i]->parent = b; - - list_for_each_safe(p, h, &b->contacts) { - struct contact * c; - c = list_entry(p, struct contact, next); - if (bucket_has_id(b->children[i], c->id)) { - list_del(&c->next); - --b->n_contacts; - list_add(&c->next, &b->children[i]->contacts); - ++b->children[i]->n_contacts; - } - } - - mask++; - } - - for (i = 0; i < (1L << KAD_BETA); ++i) - if (b->children[i]->n_contacts == c) - split_bucket(b->children[i]); - - return 0; -} - -/* Locked externally to mandate update as (final) part of join transaction. */ -static int dht_update_bucket(struct dht * dht, - const uint8_t * id, - uint64_t addr) -{ - struct list_head * p; - struct list_head * h; - struct bucket * b; - struct contact * c; - - assert(dht); - - b = dht_get_bucket(dht, id); - if (b == NULL) - return -1; - - c = contact_create(id, dht->b, addr); - if (c == NULL) - return -1; - - list_for_each_safe(p, h, &b->contacts) { - struct contact * d = list_entry(p, struct contact, next); - if (d->addr == addr) { - list_del(&d->next); - contact_destroy(d); - --b->n_contacts; - } - } - - if (b->n_contacts == dht->k) { - if (bucket_has_id(b, dht->id)) { - list_add_tail(&c->next, &b->contacts); - ++b->n_contacts; - if (split_bucket(b)) { - list_del(&c->next); - contact_destroy(c); - --b->n_contacts; - } - } else if (b->n_alts == dht->k) { - struct contact * d; - d = list_first_entry(&b->alts, struct contact, next); - list_del(&d->next); - contact_destroy(d); - list_add_tail(&c->next, &b->alts); - } else { - list_add_tail(&c->next, &b->alts); - ++b->n_alts; - } - } else { - list_add_tail(&c->next, &b->contacts); - ++b->n_contacts; - } - - return 0; -} - -static int send_msg(struct dht * dht, - kad_msg_t * msg, - uint64_t addr) -{ -#ifndef __DHT_TEST__ - struct shm_du_buff * sdb; - size_t len; -#endif - int retr = 0; - - if (msg->code == KAD_RESPONSE) - retr = KAD_RESP_RETR; - - pthread_rwlock_wrlock(&dht->lock); - - if (dht->id != NULL) { - msg->has_s_id = true; - msg->s_id.data = dht->id; - msg->s_id.len = dht->b; - } - - msg->s_addr = dht->addr; - - if (msg->code < KAD_STORE) { - msg->cookie = bmp_allocate(dht->cookies); - if (!bmp_is_id_valid(dht->cookies, msg->cookie)) { - pthread_rwlock_unlock(&dht->lock); - goto fail_bmp_alloc; - } - } - - pthread_rwlock_unlock(&dht->lock); - -#ifndef __DHT_TEST__ - len = kad_msg__get_packed_size(msg); - if (len == 0) - goto fail_msg; - - while (true) { - if (ipcp_sdb_reserve(&sdb, len)) - goto fail_msg; - - kad_msg__pack(msg, shm_du_buff_head(sdb)); - - if (dt_write_packet(addr, QOS_CUBE_BE, dht->fd, sdb) == 0) - break; - - ipcp_sdb_release(sdb); - - sleep(1); - - if (--retr < 0) - goto fail_msg; - } - -#else - (void) addr; - (void) retr; -#endif /* __DHT_TEST__ */ - - if (msg->code < KAD_STORE && dht_get_state(dht) != DHT_SHUTDOWN) - kad_req_create(dht, msg, addr); - - return msg->cookie; -#ifndef __DHT_TEST__ - fail_msg: - pthread_rwlock_wrlock(&dht->lock); - bmp_release(dht->cookies, msg->cookie); - pthread_rwlock_unlock(&dht->lock); -#endif /* !__DHT_TEST__ */ - fail_bmp_alloc: - return -1; -} - -static struct dht_entry * dht_find_entry(struct dht * dht, - const uint8_t * key) -{ - struct list_head * p; - - list_for_each(p, &dht->entries) { - struct dht_entry * e = list_entry(p, struct dht_entry, next); - if (!memcmp(key, e->key, dht->b)) - return e; - } - - return NULL; -} - -static int kad_add(struct dht * dht, - const kad_contact_msg_t * contacts, - ssize_t n, - time_t exp) -{ - struct dht_entry * e; - - pthread_rwlock_wrlock(&dht->lock); - - while (n-- > 0) { - if (contacts[n].id.len != dht->b) - log_warn("Bad key length in contact data."); - - e = dht_find_entry(dht, contacts[n].id.data); - if (e != NULL) { - if (dht_entry_add_addr(e, contacts[n].addr, exp)) - goto fail; - } else { - e = dht_entry_create(dht, contacts[n].id.data); - if (e == NULL) - goto fail; - - if (dht_entry_add_addr(e, contacts[n].addr, exp)) { - dht_entry_destroy(e); - goto fail; - } - - list_add(&e->next, &dht->entries); - } - } - - pthread_rwlock_unlock(&dht->lock); - return 0; - - fail: - pthread_rwlock_unlock(&dht->lock); - return -ENOMEM; -} - -static int wait_resp(struct dht * dht, - kad_msg_t * msg, - time_t timeo) -{ - struct kad_req * req; - - assert(dht); - assert(msg); - - pthread_rwlock_rdlock(&dht->lock); - - req = dht_find_request(dht, msg); - if (req == NULL) { - pthread_rwlock_unlock(&dht->lock); - return -EPERM; - } - - pthread_rwlock_unlock(&dht->lock); - - return kad_req_wait(req, timeo); -} - -static int kad_store(struct dht * dht, - const uint8_t * key, - uint64_t addr, - uint64_t r_addr, - time_t ttl) -{ - kad_msg_t msg = KAD_MSG__INIT; - kad_contact_msg_t cmsg = KAD_CONTACT_MSG__INIT; - kad_contact_msg_t * cmsgp[1]; - - cmsg.id.data = (uint8_t *) key; - cmsg.addr = addr; - - pthread_rwlock_rdlock(&dht->lock); - - cmsg.id.len = dht->b; - - pthread_rwlock_unlock(&dht->lock); - - cmsgp[0] = &cmsg; - - msg.code = KAD_STORE; - msg.has_t_expire = true; - msg.t_expire = ttl; - msg.n_contacts = 1; - msg.contacts = cmsgp; - - if (send_msg(dht, &msg, r_addr) < 0) - return -1; - - return 0; -} - -static ssize_t kad_find(struct dht * dht, - struct lookup * lu, - const uint64_t * addrs, - enum kad_code code) -{ - kad_msg_t msg = KAD_MSG__INIT; - ssize_t sent = 0; - - assert(dht); - assert(lu->key); - - msg.code = code; - - msg.has_key = true; - msg.key.data = (uint8_t *) lu->key; - msg.key.len = dht->b; - - while (*addrs != 0) { - struct cookie_el * c; - int ret; - - if (*addrs == dht->addr) { - ++addrs; - continue; - } - - ret = send_msg(dht, &msg, *addrs); - if (ret < 0) - break; - - c = malloc(sizeof(*c)); - if (c == NULL) - break; - - c->cookie = (uint32_t) ret; - - pthread_mutex_lock(&lu->lock); - - list_add_tail(&c->next, &lu->cookies); - - pthread_mutex_unlock(&lu->lock); - - ++sent; - ++addrs; - } - - return sent; -} - -static void lookup_detach(struct dht * dht, - struct lookup * lu) -{ - pthread_rwlock_wrlock(&dht->lock); - - list_del(&lu->next); - - pthread_rwlock_unlock(&dht->lock); -} - -static struct lookup * kad_lookup(struct dht * dht, - const uint8_t * id, - enum kad_code code) -{ - uint64_t addrs[KAD_ALPHA + 1]; - enum lookup_state state; - struct lookup * lu; - - lu = lookup_create(dht, id); - if (lu == NULL) - return NULL; - - lookup_new_addrs(lu, addrs); - - if (addrs[0] == 0) { - lookup_detach(dht, lu); - lookup_destroy(lu); - return NULL; - } - - if (kad_find(dht, lu, addrs, code) == 0) { - lookup_detach(dht, lu); - return lu; - } - - while ((state = lookup_wait(lu)) != LU_COMPLETE) { - switch (state) { - case LU_UPDATE: - lookup_new_addrs(lu, addrs); - if (addrs[0] == 0) - break; - - kad_find(dht, lu, addrs, code); - break; - case LU_DESTROY: - lookup_detach(dht, lu); - lookup_set_state(lu, LU_NULL); - return NULL; - default: - break; - } - } - - assert(state = LU_COMPLETE); - - lookup_detach(dht, lu); - - return lu; -} - -static void kad_publish(struct dht * dht, - const uint8_t * key, - uint64_t addr, - time_t exp) -{ - struct lookup * lu; - uint64_t * addrs; - ssize_t n; - size_t k; - time_t t_expire; - - - assert(dht); - assert(key); - - pthread_rwlock_rdlock(&dht->lock); - - k = dht->k; - t_expire = dht->t_expire; - - pthread_rwlock_unlock(&dht->lock); - - addrs = malloc(k * sizeof(*addrs)); - if (addrs == NULL) - return; - - lu = kad_lookup(dht, key, KAD_FIND_NODE); - if (lu == NULL) { - free(addrs); - return; - } - - n = lookup_contact_addrs(lu, addrs); - - while (n-- > 0) { - if (addrs[n] == dht->addr) { - kad_contact_msg_t msg = KAD_CONTACT_MSG__INIT; - msg.id.data = (uint8_t *) key; - msg.id.len = dht->b; - msg.addr = addr; - kad_add(dht, &msg, 1, exp); - } else { - if (kad_store(dht, key, addr, addrs[n], t_expire)) - log_warn("Failed to send store message."); - } - } - - lookup_destroy(lu); - - free(addrs); -} - -static int kad_join(struct dht * dht, - uint64_t addr) -{ - kad_msg_t msg = KAD_MSG__INIT; - - msg.code = KAD_JOIN; - - msg.has_alpha = true; - msg.has_b = true; - msg.has_k = true; - msg.has_t_refresh = true; - msg.has_t_replicate = true; - msg.alpha = KAD_ALPHA; - msg.k = KAD_K; - msg.t_refresh = KAD_T_REFR; - msg.t_replicate = KAD_T_REPL; - - pthread_rwlock_rdlock(&dht->lock); - - msg.b = dht->b; - - pthread_rwlock_unlock(&dht->lock); - - if (send_msg(dht, &msg, addr) < 0) - return -1; - - if (wait_resp(dht, &msg, KAD_T_JOIN) < 0) - return -1; - - dht->id = create_id(dht->b); - if (dht->id == NULL) - return -1; - - pthread_rwlock_wrlock(&dht->lock); - - dht_update_bucket(dht, dht->id, dht->addr); - - pthread_rwlock_unlock(&dht->lock); - - return 0; -} - -static void dht_dead_peer(struct dht * dht, - uint8_t * key, - uint64_t addr) -{ - struct list_head * p; - struct list_head * h; - struct bucket * b; - - b = dht_get_bucket(dht, key); - - list_for_each_safe(p, h, &b->contacts) { - struct contact * c = list_entry(p, struct contact, next); - if (b->n_contacts + b->n_alts <= dht->k) { - ++c->fails; - return; - } - - if (c->addr == addr) { - list_del(&c->next); - contact_destroy(c); - --b->n_contacts; - break; - } - } - - while (b->n_contacts < dht->k && b->n_alts > 0) { - struct contact * c; - c = list_first_entry(&b->alts, struct contact, next); - list_del(&c->next); - --b->n_alts; - list_add(&c->next, &b->contacts); - ++b->n_contacts; - } -} - -static int dht_del(struct dht * dht, - const uint8_t * key, - uint64_t addr) -{ - struct dht_entry * e; - - pthread_rwlock_wrlock(&dht->lock); - - e = dht_find_entry(dht, key); - if (e == NULL) { - pthread_rwlock_unlock(&dht->lock); - return -EPERM; - } - - dht_entry_del_addr(e, addr); - - pthread_rwlock_unlock(&dht->lock); - - return 0; -} - -static buffer_t dht_retrieve(struct dht * dht, - const uint8_t * key) -{ - struct dht_entry * e; - struct list_head * p; - buffer_t buf; - uint64_t * pos; - size_t addrs = 0; - - pthread_rwlock_rdlock(&dht->lock); - - e = dht_find_entry(dht, key); - if (e == NULL) - goto fail; - - buf.len = MIN(DHT_RETR_ADDR, e->n_vals); - if (buf.len == 0) - goto fail; - - pos = malloc(sizeof(dht->addr) * buf.len); - if (pos == NULL) - goto fail; - - buf.data = (uint8_t *) pos; - - list_for_each(p, &e->vals) { - struct val * v = list_entry(p, struct val, next); - *pos++ = v->addr; - if (++addrs >= buf.len) - break; - } - - pthread_rwlock_unlock(&dht->lock); - - return buf; - - fail: - pthread_rwlock_unlock(&dht->lock); - buf.len = 0; - - return buf; -} - -static ssize_t dht_get_contacts(struct dht * dht, - const uint8_t * key, - kad_contact_msg_t *** msgs) -{ - struct list_head l; - struct list_head * p; - struct list_head * h; - size_t len; - size_t i = 0; - - list_head_init(&l); - - pthread_rwlock_wrlock(&dht->lock); - - len = dht_contact_list(dht, &l, key); - if (len == 0) { - pthread_rwlock_unlock(&dht->lock); - return 0; - } - - *msgs = malloc(len * sizeof(**msgs)); - if (*msgs == NULL) { - pthread_rwlock_unlock(&dht->lock); - return 0; - } - - list_for_each_safe(p, h, &l) { - struct contact * c = list_entry(p, struct contact, next); - (*msgs)[i] = malloc(sizeof(***msgs)); - if ((*msgs)[i] == NULL) { - pthread_rwlock_unlock(&dht->lock); - while (i > 0) - free(*msgs[--i]); - free(*msgs); - return 0; - } - - kad_contact_msg__init((*msgs)[i]); - - (*msgs)[i]->id.data = c->id; - (*msgs)[i]->id.len = dht->b; - (*msgs)[i++]->addr = c->addr; - list_del(&c->next); - free(c); - } - - pthread_rwlock_unlock(&dht->lock); - - return i; -} - -static time_t gcd(time_t a, - time_t b) -{ - if (a == 0) - return b; - - return gcd(b % a, a); -} - -static void * work(void * o) -{ - struct dht * dht; - struct timespec now; - struct list_head * p; - struct list_head * h; - struct list_head reflist; - time_t intv; - struct lookup * lu; - - dht = (struct dht *) o; - - pthread_rwlock_rdlock(&dht->lock); - - intv = gcd(dht->t_expire, dht->t_repub); - intv = gcd(intv, gcd(KAD_T_REPL, KAD_T_REFR)) / 2; - - pthread_rwlock_unlock(&dht->lock); - - list_head_init(&reflist); - - while (true) { - clock_gettime(CLOCK_REALTIME_COARSE, &now); - - pthread_rwlock_wrlock(&dht->lock); - - /* Republish registered hashes. */ - list_for_each(p, &dht->refs) { - struct ref_entry * e; - uint8_t * key; - uint64_t addr; - time_t t_expire; - e = list_entry(p, struct ref_entry, next); - if (now.tv_sec > e->t_rep) { - key = dht_dup_key(e->key, dht->b); - if (key == NULL) - continue; - addr = dht->addr; - t_expire = dht->t_expire; - e->t_rep = now.tv_sec + dht->t_repub; - - pthread_rwlock_unlock(&dht->lock); - kad_publish(dht, key, addr, t_expire); - pthread_rwlock_wrlock(&dht->lock); - free(key); - } - } - - /* Remove stale entries and republish if necessary. */ - list_for_each_safe(p, h, &dht->entries) { - struct list_head * p1; - struct list_head * h1; - struct dht_entry * e; - uint8_t * key; - time_t t_expire; - e = list_entry (p, struct dht_entry, next); - list_for_each_safe(p1, h1, &e->vals) { - struct val * v; - uint64_t addr; - v = list_entry(p1, struct val, next); - if (now.tv_sec > v->t_exp) { - list_del(&v->next); - val_destroy(v); - continue; - } - - if (now.tv_sec > v->t_rep) { - key = dht_dup_key(e->key, dht->b); - addr = v->addr; - t_expire = dht->t_expire = now.tv_sec; - v->t_rep = now.tv_sec + dht->t_replic; - pthread_rwlock_unlock(&dht->lock); - kad_publish(dht, key, addr, t_expire); - pthread_rwlock_wrlock(&dht->lock); - free(key); - } - } - } - - /* Check the requests list for unresponsive nodes. */ - list_for_each_safe(p, h, &dht->requests) { - struct kad_req * r; - r = list_entry(p, struct kad_req, next); - if (now.tv_sec > r->t_exp) { - list_del(&r->next); - bmp_release(dht->cookies, r->cookie); - dht_dead_peer(dht, r->key, r->addr); - kad_req_destroy(r); - } - } - - /* Refresh unaccessed buckets. */ - bucket_refresh(dht, dht->buckets, now.tv_sec, &reflist); - - pthread_rwlock_unlock(&dht->lock); - - list_for_each_safe(p, h, &reflist) { - struct contact * c; - c = list_entry(p, struct contact, next); - lu = kad_lookup(dht, c->id, KAD_FIND_NODE); - if (lu != NULL) - lookup_destroy(lu); - list_del(&c->next); - contact_destroy(c); - } - - sleep(intv); - } - - return (void *) 0; -} - -static int kad_handle_join_resp(struct dht * dht, - struct kad_req * req, - kad_msg_t * msg) -{ - assert(dht); - assert(req); - assert(msg); - - /* We might send version numbers later to warn of updates if needed. */ - if (!(msg->has_alpha && msg->has_b && msg->has_k && msg->has_t_expire && - msg->has_t_refresh && msg->has_t_replicate)) { - log_warn("Join refused by remote."); - return -1; - } - - if (msg->b < sizeof(uint64_t)) { - log_err("Hash sizes less than 8 bytes unsupported."); - return -1; - } - - pthread_rwlock_wrlock(&dht->lock); - - dht->buckets = bucket_create(); - if (dht->buckets == NULL) { - pthread_rwlock_unlock(&dht->lock); - return -1; - } - - /* Likely corrupt packet. The member will refuse, we might here too. */ - if (msg->alpha != KAD_ALPHA || msg->k != KAD_K) - log_warn("Different kademlia parameters detected."); - - if (msg->t_replicate != KAD_T_REPL) - log_warn("Different kademlia replication time detected."); - - if (msg->t_refresh != KAD_T_REFR) - log_warn("Different kademlia refresh time detected."); - - dht->k = msg->k; - dht->b = msg->b; - dht->t_expire = msg->t_expire; - dht->t_repub = MAX(1, dht->t_expire - 10); - - if (pthread_create(&dht->worker, NULL, work, dht)) { - bucket_destroy(dht->buckets); - pthread_rwlock_unlock(&dht->lock); - return -1; - } - - kad_req_respond(req); - - dht_update_bucket(dht, msg->s_id.data, msg->s_addr); - - pthread_rwlock_unlock(&dht->lock); - - log_dbg("Enrollment of DHT completed."); - - return 0; -} - -static int kad_handle_find_resp(struct dht * dht, - struct kad_req * req, - kad_msg_t * msg) -{ - struct lookup * lu; - - assert(dht); - assert(req); - assert(msg); - - pthread_rwlock_rdlock(&dht->lock); - - lu = dht_find_lookup(dht, req->cookie); - if (lu == NULL) { - pthread_rwlock_unlock(&dht->lock); - return -1; - } - - lookup_update(dht, lu, msg); - - pthread_rwlock_unlock(&dht->lock); - - return 0; -} - -static void kad_handle_response(struct dht * dht, - kad_msg_t * msg) -{ - struct kad_req * req; - - assert(dht); - assert(msg); - - pthread_rwlock_wrlock(&dht->lock); - - req = dht_find_request(dht, msg); - if (req == NULL) { - pthread_rwlock_unlock(&dht->lock); - return; - } - - bmp_release(dht->cookies, req->cookie); - list_del(&req->next); - - pthread_rwlock_unlock(&dht->lock); - - switch(req->code) { - case KAD_JOIN: - if (kad_handle_join_resp(dht, req, msg)) - log_err("Enrollment of DHT failed."); - break; - case KAD_FIND_VALUE: - case KAD_FIND_NODE: - if (dht_get_state(dht) != DHT_RUNNING) - break; - kad_handle_find_resp(dht, req, msg); - break; - default: - break; - } - - kad_req_destroy(req); -} - -int dht_bootstrap(struct dht * dht, - size_t b, - time_t t_expire) -{ - assert(dht); - - pthread_rwlock_wrlock(&dht->lock); - - dht->id = create_id(b); - if (dht->id == NULL) - goto fail_id; - - dht->buckets = bucket_create(); - if (dht->buckets == NULL) - goto fail_buckets; - - dht->buckets->depth = 0; - dht->buckets->mask = 0; - - dht->b = b / CHAR_BIT; - dht->t_expire = MAX(2, t_expire); - dht->t_repub = MAX(1, t_expire - 10); - dht->k = KAD_K; - - if (pthread_create(&dht->worker, NULL, work, dht)) - goto fail_pthread_create; - - dht->state = DHT_RUNNING; - - dht_update_bucket(dht, dht->id, dht->addr); - - pthread_rwlock_unlock(&dht->lock); - - return 0; - - fail_pthread_create: - bucket_destroy(dht->buckets); - dht->buckets = NULL; - fail_buckets: - free(dht->id); - dht->id = NULL; - fail_id: - pthread_rwlock_unlock(&dht->lock); - return -1; -} - -static struct ref_entry * ref_entry_get(struct dht * dht, - const uint8_t * key) -{ - struct list_head * p; - - list_for_each(p, &dht->refs) { - struct ref_entry * r = list_entry(p, struct ref_entry, next); - if (!memcmp(key, r->key, dht-> b) ) - return r; - } - - return NULL; -} - -int dht_reg(struct dht * dht, - const uint8_t * key) -{ - struct ref_entry * e; - uint64_t addr; - time_t t_expire; - - assert(dht); - assert(key); - assert(dht->addr != 0); - - if (dht_wait_running(dht)) - return -1; - - pthread_rwlock_wrlock(&dht->lock); - - if (ref_entry_get(dht, key) != NULL) { - log_dbg("Name already registered."); - pthread_rwlock_unlock(&dht->lock); - return 0; - } - - e = ref_entry_create(dht, key); - if (e == NULL) { - pthread_rwlock_unlock(&dht->lock); - return -ENOMEM; - } - - list_add(&e->next, &dht->refs); - - t_expire = dht->t_expire; - addr = dht->addr; - - pthread_rwlock_unlock(&dht->lock); - - kad_publish(dht, key, addr, t_expire); - - return 0; -} - -int dht_unreg(struct dht * dht, - const uint8_t * key) -{ - struct list_head * p; - struct list_head * h; - - assert(dht); - assert(key); - - if (dht_get_state(dht) != DHT_RUNNING) - return -1; - - pthread_rwlock_wrlock(&dht->lock); - - list_for_each_safe(p, h, &dht->refs) { - struct ref_entry * r = list_entry(p, struct ref_entry, next); - if (!memcmp(key, r->key, dht-> b) ) { - list_del(&r->next); - ref_entry_destroy(r); - } - } - - dht_del(dht, key, dht->addr); - - pthread_rwlock_unlock(&dht->lock); - - return 0; -} - -uint64_t dht_query(struct dht * dht, - const uint8_t * key) -{ - struct dht_entry * e; - struct lookup * lu; - uint64_t addrs[KAD_K]; - size_t n; - - addrs[0] = 0; - - if (dht_wait_running(dht)) - return 0; - - pthread_rwlock_rdlock(&dht->lock); - - e = dht_find_entry(dht, key); - if (e != NULL) - addrs[0] = dht_entry_get_addr(dht, e); - - pthread_rwlock_unlock(&dht->lock); - - if (addrs[0] != 0) - return addrs[0]; - - lu = kad_lookup(dht, key, KAD_FIND_VALUE); - if (lu == NULL) - return 0; - - n = lookup_get_addrs(lu, addrs); - if (n == 0) { - lookup_destroy(lu); - return 0; - } - - lookup_destroy(lu); - - /* Current behaviour is anycast and return the first peer address. */ - if (addrs[0] != dht->addr) - return addrs[0]; - - if (n > 1) - return addrs[1]; - - return 0; -} - -static void * dht_handle_packet(void * o) -{ - struct dht * dht = (struct dht *) o; - - assert(dht); - - while (true) { - kad_msg_t * msg; - kad_contact_msg_t ** cmsgs; - kad_msg_t resp_msg = KAD_MSG__INIT; - uint64_t addr; - buffer_t buf; - size_t i; - size_t b; - size_t t_expire; - struct cmd * cmd; - - pthread_mutex_lock(&dht->mtx); - - pthread_cleanup_push((void *)(void *) pthread_mutex_unlock, - &dht->mtx); - - while (list_is_empty(&dht->cmds)) - pthread_cond_wait(&dht->cond, &dht->mtx); - - cmd = list_last_entry(&dht->cmds, struct cmd, next); - list_del(&cmd->next); - - pthread_cleanup_pop(true); - - i = shm_du_buff_tail(cmd->sdb) - shm_du_buff_head(cmd->sdb); - - msg = kad_msg__unpack(NULL, i, shm_du_buff_head(cmd->sdb)); -#ifndef __DHT_TEST__ - ipcp_sdb_release(cmd->sdb); -#endif - free(cmd); - - if (msg == NULL) { - log_err("Failed to unpack message."); - continue; - } - - if (msg->code != KAD_RESPONSE && dht_wait_running(dht)) { - kad_msg__free_unpacked(msg, NULL); - log_dbg("Got a request message when not running."); - continue; - } - - pthread_rwlock_rdlock(&dht->lock); - - b = dht->b; - t_expire = dht->t_expire; - - pthread_rwlock_unlock(&dht->lock); - - if (msg->has_key && msg->key.len != b) { - kad_msg__free_unpacked(msg, NULL); - log_warn("Bad key in message."); - continue; - } - - if (msg->has_s_id && !msg->has_b && msg->s_id.len != b) { - kad_msg__free_unpacked(msg, NULL); - log_warn("Bad source ID in message of type %d.", - msg->code); - continue; - } - - tpm_dec(dht->tpm); - - addr = msg->s_addr; - - resp_msg.code = KAD_RESPONSE; - resp_msg.cookie = msg->cookie; - - switch(msg->code) { - case KAD_JOIN: - /* Refuse enrollee on check fails. */ - if (msg->alpha != KAD_ALPHA || msg->k != KAD_K) { - log_warn("Parameter mismatch. " - "DHT enrolment refused."); - break; - } - - if (msg->t_replicate != KAD_T_REPL) { - log_warn("Replication time mismatch. " - "DHT enrolment refused."); - - break; - } - - if (msg->t_refresh != KAD_T_REFR) { - log_warn("Refresh time mismatch. " - "DHT enrolment refused."); - break; - } - - resp_msg.has_alpha = true; - resp_msg.has_b = true; - resp_msg.has_k = true; - resp_msg.has_t_expire = true; - resp_msg.has_t_refresh = true; - resp_msg.has_t_replicate = true; - resp_msg.alpha = KAD_ALPHA; - resp_msg.b = b; - resp_msg.k = KAD_K; - resp_msg.t_expire = t_expire; - resp_msg.t_refresh = KAD_T_REFR; - resp_msg.t_replicate = KAD_T_REPL; - break; - case KAD_FIND_VALUE: - buf = dht_retrieve(dht, msg->key.data); - if (buf.len != 0) { - resp_msg.n_addrs = buf.len; - resp_msg.addrs = (uint64_t *) buf.data; - break; - } - /* FALLTHRU */ - case KAD_FIND_NODE: - /* Return k closest contacts. */ - resp_msg.n_contacts = - dht_get_contacts(dht, msg->key.data, &cmsgs); - resp_msg.contacts = cmsgs; - break; - case KAD_STORE: - if (msg->n_contacts < 1) { - log_warn("No contacts in store message."); - break; - } - - if (!msg->has_t_expire) { - log_warn("No expiry time in store message."); - break; - } - - kad_add(dht, *msg->contacts, msg->n_contacts, - msg->t_expire); - break; - case KAD_RESPONSE: - kad_handle_response(dht, msg); - break; - default: - assert(false); - break; - } - - if (msg->code != KAD_JOIN) { - pthread_rwlock_wrlock(&dht->lock); - if (dht_get_state(dht) == DHT_JOINING && - dht->buckets == NULL) { - pthread_rwlock_unlock(&dht->lock); - break; - } - - if (dht_update_bucket(dht, msg->s_id.data, addr)) - log_warn("Failed to update bucket."); - pthread_rwlock_unlock(&dht->lock); - } - - if (msg->code < KAD_STORE && send_msg(dht, &resp_msg, addr) < 0) - log_warn("Failed to send response."); - - kad_msg__free_unpacked(msg, NULL); - - if (resp_msg.n_addrs > 0) - free(resp_msg.addrs); - - if (resp_msg.n_contacts == 0) { - tpm_inc(dht->tpm); - continue; - } - - for (i = 0; i < resp_msg.n_contacts; ++i) - kad_contact_msg__free_unpacked(resp_msg.contacts[i], - NULL); - free(resp_msg.contacts); - - tpm_inc(dht->tpm); - } - - return (void *) 0; -} - -static void dht_post_packet(void * comp, - struct shm_du_buff * sdb) -{ - struct cmd * cmd; - struct dht * dht = (struct dht *) comp; - - if (dht_get_state(dht) == DHT_SHUTDOWN) { -#ifndef __DHT_TEST__ - ipcp_sdb_release(sdb); -#endif - return; - } - - cmd = malloc(sizeof(*cmd)); - if (cmd == NULL) { - log_err("Command failed. Out of memory."); - return; - } - - cmd->sdb = sdb; - - pthread_mutex_lock(&dht->mtx); - - list_add(&cmd->next, &dht->cmds); - - pthread_cond_signal(&dht->cond); - - pthread_mutex_unlock(&dht->mtx); -} - -void dht_destroy(struct dht * dht) -{ - struct list_head * p; - struct list_head * h; - - if (dht == NULL) - return; - -#ifndef __DHT_TEST__ - tpm_stop(dht->tpm); - - tpm_destroy(dht->tpm); -#endif - if (dht_get_state(dht) == DHT_RUNNING) { - dht_set_state(dht, DHT_SHUTDOWN); - pthread_cancel(dht->worker); - pthread_join(dht->worker, NULL); - } - - pthread_rwlock_wrlock(&dht->lock); - - list_for_each_safe(p, h, &dht->cmds) { - struct cmd * c = list_entry(p, struct cmd, next); - list_del(&c->next); -#ifndef __DHT_TEST__ - ipcp_sdb_release(c->sdb); -#endif - free(c); - } - - list_for_each_safe(p, h, &dht->entries) { - struct dht_entry * e = list_entry(p, struct dht_entry, next); - list_del(&e->next); - dht_entry_destroy(e); - } - - list_for_each_safe(p, h, &dht->requests) { - struct kad_req * r = list_entry(p, struct kad_req, next); - list_del(&r->next); - kad_req_destroy(r); - } - - list_for_each_safe(p, h, &dht->refs) { - struct ref_entry * e = list_entry(p, struct ref_entry, next); - list_del(&e->next); - ref_entry_destroy(e); - } - - list_for_each_safe(p, h, &dht->lookups) { - struct lookup * l = list_entry(p, struct lookup, next); - list_del(&l->next); - lookup_destroy(l); - } - - pthread_rwlock_unlock(&dht->lock); - - if (dht->buckets != NULL) - bucket_destroy(dht->buckets); - - bmp_destroy(dht->cookies); - - pthread_mutex_destroy(&dht->mtx); - - pthread_rwlock_destroy(&dht->lock); - - free(dht->id); - - free(dht); -} - -static void * join_thr(void * o) -{ - struct join_info * info = (struct join_info *) o; - struct lookup * lu; - size_t retr = 0; - - assert(info); - - while (kad_join(info->dht, info->addr)) { - if (dht_get_state(info->dht) == DHT_SHUTDOWN) { - log_dbg("DHT enrollment aborted."); - goto finish; - } - - if (retr++ == KAD_JOIN_RETR) { - dht_set_state(info->dht, DHT_INIT); - log_warn("DHT enrollment attempt failed."); - goto finish; - } - - sleep(KAD_JOIN_INTV); - } - - dht_set_state(info->dht, DHT_RUNNING); - - lu = kad_lookup(info->dht, info->dht->id, KAD_FIND_NODE); - if (lu != NULL) - lookup_destroy(lu); - - finish: - free(info); - - return (void *) 0; -} - -static void handle_event(void * self, - int event, - const void * o) -{ - struct dht * dht = (struct dht *) self; - - if (event == NOTIFY_DT_CONN_ADD) { - pthread_t thr; - struct join_info * inf; - struct conn * c = (struct conn *) o; - struct timespec slack = {0, DHT_ENROLL_SLACK * MILLION}; - - /* Give the pff some time to update for the new link. */ - nanosleep(&slack, NULL); - - switch(dht_get_state(dht)) { - case DHT_INIT: - inf = malloc(sizeof(*inf)); - if (inf == NULL) - break; - - inf->dht = dht; - inf->addr = c->conn_info.addr; - - if (dht_set_state(dht, DHT_JOINING) == 0 || - dht_wait_running(dht)) { - if (pthread_create(&thr, NULL, join_thr, inf)) { - dht_set_state(dht, DHT_INIT); - free(inf); - return; - } - pthread_detach(thr); - } else { - free(inf); - } - break; - case DHT_RUNNING: - /* - * FIXME: this lookup for effiency reasons - * causes a SEGV when stressed with rapid - * enrollments. - * lu = kad_lookup(dht, dht->id, KAD_FIND_NODE); - * if (lu != NULL) - * lookup_destroy(lu); - */ - break; - default: - break; - } - } -} - -struct dht * dht_create(uint64_t addr) -{ - struct dht * dht; - - dht = malloc(sizeof(*dht)); - if (dht == NULL) - goto fail_malloc; - - dht->buckets = NULL; - - list_head_init(&dht->entries); - list_head_init(&dht->requests); - list_head_init(&dht->refs); - list_head_init(&dht->lookups); - list_head_init(&dht->cmds); - - if (pthread_rwlock_init(&dht->lock, NULL)) - goto fail_rwlock; - - if (pthread_mutex_init(&dht->mtx, NULL)) - goto fail_mutex; - - if (pthread_cond_init(&dht->cond, NULL)) - goto fail_cond; - - dht->cookies = bmp_create(DHT_MAX_REQS, 1); - if (dht->cookies == NULL) - goto fail_bmp; - - dht->b = 0; - dht->addr = addr; - dht->id = NULL; -#ifndef __DHT_TEST__ - dht->tpm = tpm_create(2, 1, dht_handle_packet, dht); - if (dht->tpm == NULL) - goto fail_tpm_create; - - if (tpm_start(dht->tpm)) - goto fail_tpm_start; - - dht->fd = dt_reg_comp(dht, &dht_post_packet, DHT); - notifier_reg(handle_event, dht); -#else - (void) handle_event; - (void) dht_handle_packet; - (void) dht_post_packet; -#endif - dht->state = DHT_INIT; - - return dht; -#ifndef __DHT_TEST__ - fail_tpm_start: - tpm_destroy(dht->tpm); - fail_tpm_create: - bmp_destroy(dht->cookies); -#endif - fail_bmp: - pthread_cond_destroy(&dht->cond); - fail_cond: - pthread_mutex_destroy(&dht->mtx); - fail_mutex: - pthread_rwlock_destroy(&dht->lock); - fail_rwlock: - free(dht); - fail_malloc: - return NULL; -} |