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/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <libwebsockets.h>
#include "private-lib-core.h"
/* requires context->lock */
static void
__lws_peer_remove_from_peer_wait_list(struct lws_context *context,
struct lws_peer *peer)
{
struct lws_peer *df;
lws_start_foreach_llp(struct lws_peer **, p, context->peer_wait_list) {
if (*p == peer) {
df = *p;
*p = df->peer_wait_list;
df->peer_wait_list = NULL;
return;
}
} lws_end_foreach_llp(p, peer_wait_list);
}
/* requires context->lock */
static void
__lws_peer_add_to_peer_wait_list(struct lws_context *context,
struct lws_peer *peer)
{
__lws_peer_remove_from_peer_wait_list(context, peer);
peer->peer_wait_list = context->peer_wait_list;
context->peer_wait_list = peer;
}
struct lws_peer *
lws_get_or_create_peer(struct lws_vhost *vhost, lws_sockfd_type sockfd)
{
struct lws_context *context = vhost->context;
socklen_t rlen = 0;
void *q;
uint8_t *q8;
struct lws_peer *peer;
uint32_t hash = 0;
int n, af = AF_INET;
struct sockaddr_storage addr;
if (vhost->options & LWS_SERVER_OPTION_UNIX_SOCK)
return NULL;
#ifdef LWS_WITH_IPV6
if (LWS_IPV6_ENABLED(vhost)) {
af = AF_INET6;
}
#endif
rlen = sizeof(addr);
if (getpeername(sockfd, (struct sockaddr*)&addr, &rlen))
/* eg, udp doesn't have to have a peer */
return NULL;
#ifdef LWS_WITH_IPV6
if (af == AF_INET)
#endif
{
struct sockaddr_in *s = (struct sockaddr_in *)&addr;
q = &s->sin_addr;
rlen = sizeof(s->sin_addr);
}
#ifdef LWS_WITH_IPV6
else {
struct sockaddr_in6 *s = (struct sockaddr_in6 *)&addr;
q = &s->sin6_addr;
rlen = sizeof(s->sin6_addr);
}
#endif
q8 = q;
for (n = 0; n < (int)rlen; n++)
hash = (((hash << 4) | (hash >> 28)) * n) ^ q8[n];
hash = hash % context->pl_hash_elements;
lws_context_lock(context, "peer search"); /* <======================= */
lws_start_foreach_ll(struct lws_peer *, peerx,
context->pl_hash_table[hash]) {
if (peerx->af == af && !memcmp(q, peerx->addr, rlen)) {
lws_context_unlock(context); /* === */
return peerx;
}
} lws_end_foreach_ll(peerx, next);
lwsl_info("%s: creating new peer\n", __func__);
peer = lws_zalloc(sizeof(*peer), "peer");
if (!peer) {
lws_context_unlock(context); /* === */
lwsl_err("%s: OOM for new peer\n", __func__);
return NULL;
}
context->count_peers++;
peer->next = context->pl_hash_table[hash];
peer->hash = hash;
peer->af = af;
context->pl_hash_table[hash] = peer;
memcpy(peer->addr, q, rlen);
time(&peer->time_created);
/*
* On creation, the peer has no wsi attached, so is created on the
* wait list. When a wsi is added it is removed from the wait list.
*/
time(&peer->time_closed_all);
__lws_peer_add_to_peer_wait_list(context, peer);
lws_context_unlock(context); /* ====================================> */
return peer;
}
/* requires context->lock */
static int
__lws_peer_destroy(struct lws_context *context, struct lws_peer *peer)
{
lws_start_foreach_llp(struct lws_peer **, p,
context->pl_hash_table[peer->hash]) {
if (*p == peer) {
struct lws_peer *df = *p;
*p = df->next;
lws_free(df);
context->count_peers--;
return 0;
}
} lws_end_foreach_llp(p, next);
return 1;
}
void
lws_peer_cull_peer_wait_list(struct lws_context *context)
{
struct lws_peer *df;
time_t t;
time(&t);
if (context->next_cull && t < context->next_cull)
return;
lws_context_lock(context, "peer cull"); /* <========================= */
context->next_cull = t + 5;
lws_start_foreach_llp(struct lws_peer **, p, context->peer_wait_list) {
if (t - (*p)->time_closed_all > 10) {
df = *p;
/* remove us from the peer wait list */
*p = df->peer_wait_list;
df->peer_wait_list = NULL;
__lws_peer_destroy(context, df);
continue; /* we already point to next, if any */
}
} lws_end_foreach_llp(p, peer_wait_list);
lws_context_unlock(context); /* ====================================> */
}
void
lws_peer_add_wsi(struct lws_context *context, struct lws_peer *peer,
struct lws *wsi)
{
if (!peer)
return;
lws_context_lock(context, "peer add"); /* <========================== */
peer->count_wsi++;
wsi->peer = peer;
__lws_peer_remove_from_peer_wait_list(context, peer);
lws_context_unlock(context); /* ====================================> */
}
void
lws_peer_dump_from_wsi(struct lws *wsi)
{
struct lws_peer *peer;
if (!wsi || !wsi->peer)
return;
peer = wsi->peer;
#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
lwsl_notice("%s: wsi %p: created %llu: wsi: %d/%d, ah %d/%d\n",
__func__,
wsi, (unsigned long long)peer->time_created,
peer->count_wsi, peer->total_wsi,
peer->http.count_ah, peer->http.total_ah);
#else
lwsl_notice("%s: wsi %p: created %llu: wsi: %d/%d\n", __func__,
wsi, (unsigned long long)peer->time_created,
peer->count_wsi, peer->total_wsi);
#endif
}
void
lws_peer_track_wsi_close(struct lws_context *context, struct lws_peer *peer)
{
if (!peer)
return;
lws_context_lock(context, "peer wsi close"); /* <==================== */
assert(peer->count_wsi);
peer->count_wsi--;
if (!peer->count_wsi
#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
&& !peer->http.count_ah
#endif
) {
/*
* in order that we can accumulate peer activity correctly
* allowing for periods when the peer has no connections,
* we don't synchronously destroy the peer when his last
* wsi closes. Instead we mark the time his last wsi
* closed and add him to a peer_wait_list to be reaped
* later if no further activity is coming.
*/
time(&peer->time_closed_all);
__lws_peer_add_to_peer_wait_list(context, peer);
}
lws_context_unlock(context); /* ====================================> */
}
#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
int
lws_peer_confirm_ah_attach_ok(struct lws_context *context,
struct lws_peer *peer)
{
if (!peer)
return 0;
if (context->ip_limit_ah &&
peer->http.count_ah >= context->ip_limit_ah) {
lwsl_info("peer reached ah limit %d, deferring\n",
context->ip_limit_ah);
return 1;
}
return 0;
}
void
lws_peer_track_ah_detach(struct lws_context *context, struct lws_peer *peer)
{
if (!peer)
return;
lws_context_lock(context, "peer ah detach"); /* <==================== */
assert(peer->http.count_ah);
peer->http.count_ah--;
lws_context_unlock(context); /* ====================================> */
}
#endif