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SSLproxy/pxythrmgr.c

287 lines
7.3 KiB
C

/*
* SSLsplit - transparent SSL/TLS interception
* Copyright (c) 2009-2016, Daniel Roethlisberger <daniel@roe.ch>
* All rights reserved.
* http://www.roe.ch/SSLsplit
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include "pxythrmgr.h"
#include "sys.h"
#include "log.h"
#include <string.h>
#include <pthread.h>
/*
* Proxy thread manager: manages the connection handling worker threads
* and the per-thread resources (i.e. event bases). The load is shared
* across num_cpu * 2 connection handling threads, using the number of
* currently assigned connections as the sole metric.
*
* The attach and detach functions are thread-safe.
*/
typedef struct pxy_thr_ctx {
pthread_t thr;
size_t load;
struct event_base *evbase;
struct evdns_base *dnsbase;
int running;
} pxy_thr_ctx_t;
struct pxy_thrmgr_ctx {
int num_thr;
opts_t *opts;
pxy_thr_ctx_t **thr;
pthread_mutex_t mutex;
};
/*
* Dummy recurring timer event to prevent the event loops from exiting when
* they run out of events.
*/
static void
pxy_thrmgr_timer_cb(UNUSED evutil_socket_t fd, UNUSED short what,
UNUSED void *arg)
{
/* do nothing */
}
/*
* Thread entry point; runs the event loop of the event base.
* Does not exit until the libevent loop is broken explicitly.
*/
static void *
pxy_thrmgr_thr(void *arg)
{
pxy_thr_ctx_t *ctx = arg;
struct timeval timer_delay = {60, 0};
struct event *ev;
ev = event_new(ctx->evbase, -1, EV_PERSIST, pxy_thrmgr_timer_cb, NULL);
if (!ev)
return NULL;
evtimer_add(ev, &timer_delay);
ctx->running = 1;
event_base_dispatch(ctx->evbase);
event_free(ev);
return NULL;
}
/*
* Create new thread manager but do not start any threads yet.
* This gets called before forking to background.
*/
pxy_thrmgr_ctx_t *
pxy_thrmgr_new(opts_t *opts)
{
pxy_thrmgr_ctx_t *ctx;
if (!(ctx = malloc(sizeof(pxy_thrmgr_ctx_t))))
return NULL;
memset(ctx, 0, sizeof(pxy_thrmgr_ctx_t));
ctx->opts = opts;
ctx->num_thr = 2 * sys_get_cpu_cores();
return ctx;
}
/*
* Start the thread manager and associated threads.
* This must be called after forking.
*
* Returns -1 on failure, 0 on success.
*/
int
pxy_thrmgr_run(pxy_thrmgr_ctx_t *ctx)
{
int idx = -1, dns = 0;
dns = opts_has_dns_spec(ctx->opts);
pthread_mutex_init(&ctx->mutex, NULL);
if (!(ctx->thr = malloc(ctx->num_thr * sizeof(pxy_thr_ctx_t*)))) {
log_dbg_printf("Failed to allocate memory\n");
goto leave;
}
memset(ctx->thr, 0, ctx->num_thr * sizeof(pxy_thr_ctx_t*));
for (idx = 0; idx < ctx->num_thr; idx++) {
if (!(ctx->thr[idx] = malloc(sizeof(pxy_thr_ctx_t)))) {
log_dbg_printf("Failed to allocate memory\n");
goto leave;
}
memset(ctx->thr[idx], 0, sizeof(pxy_thr_ctx_t));
ctx->thr[idx]->evbase = event_base_new();
if (!ctx->thr[idx]->evbase) {
log_dbg_printf("Failed to create evbase %d\n", idx);
goto leave;
}
if (dns) {
/* only create dns base if we actually need it later */
ctx->thr[idx]->dnsbase = evdns_base_new(
ctx->thr[idx]->evbase, 1);
if (!ctx->thr[idx]->dnsbase) {
log_dbg_printf("Failed to create dnsbase %d\n",
idx);
goto leave;
}
}
ctx->thr[idx]->load = 0;
ctx->thr[idx]->running = 0;
}
log_dbg_printf("Initialized %d connection handling threads\n",
ctx->num_thr);
for (idx = 0; idx < ctx->num_thr; idx++) {
if (pthread_create(&ctx->thr[idx]->thr, NULL,
pxy_thrmgr_thr, ctx->thr[idx]))
goto leave_thr;
while (!ctx->thr[idx]->running) {
sched_yield();
}
}
log_dbg_printf("Started %d connection handling threads\n",
ctx->num_thr);
return 0;
leave_thr:
idx--;
while (idx >= 0) {
pthread_cancel(ctx->thr[idx]->thr);
pthread_join(ctx->thr[idx]->thr, NULL);
idx--;
}
idx = ctx->num_thr - 1;
leave:
while (idx >= 0) {
if (ctx->thr[idx]) {
if (ctx->thr[idx]->dnsbase) {
evdns_base_free(ctx->thr[idx]->dnsbase, 0);
}
if (ctx->thr[idx]->evbase) {
event_base_free(ctx->thr[idx]->evbase);
}
free(ctx->thr[idx]);
}
idx--;
}
pthread_mutex_destroy(&ctx->mutex);
if (ctx->thr) {
free(ctx->thr);
ctx->thr = NULL;
}
return -1;
}
/*
* Destroy the event manager and stop all threads.
*/
void
pxy_thrmgr_free(pxy_thrmgr_ctx_t *ctx)
{
pthread_mutex_destroy(&ctx->mutex);
if (ctx->thr) {
for (int idx = 0; idx < ctx->num_thr; idx++) {
event_base_loopbreak(ctx->thr[idx]->evbase);
sched_yield();
}
for (int idx = 0; idx < ctx->num_thr; idx++) {
pthread_join(ctx->thr[idx]->thr, NULL);
}
for (int idx = 0; idx < ctx->num_thr; idx++) {
if (ctx->thr[idx]->dnsbase) {
evdns_base_free(ctx->thr[idx]->dnsbase, 0);
}
if (ctx->thr[idx]->evbase) {
event_base_free(ctx->thr[idx]->evbase);
}
free(ctx->thr[idx]);
}
free(ctx->thr);
}
free(ctx);
}
/*
* Attach a new connection to a thread. Chooses the thread with the fewest
* currently active connections, returns the appropriate event bases.
* Returns the index of the chosen thread (for passing to _detach later).
* This function cannot fail.
*/
int
pxy_thrmgr_attach(pxy_thrmgr_ctx_t *ctx, struct event_base **evbase,
struct evdns_base **dnsbase)
{
int thridx;
size_t minload;
thridx = 0;
pthread_mutex_lock(&ctx->mutex);
minload = ctx->thr[thridx]->load;
#ifdef DEBUG_THREAD
log_dbg_printf("===> Proxy connection handler thread status:\n"
"thr[%d]: %zu\n", thridx, minload);
#endif /* DEBUG_THREAD */
for (int idx = 1; idx < ctx->num_thr; idx++) {
#ifdef DEBUG_THREAD
log_dbg_printf("thr[%d]: %zu\n", idx, ctx->thr[idx]->load);
#endif /* DEBUG_THREAD */
if (minload > ctx->thr[idx]->load) {
minload = ctx->thr[idx]->load;
thridx = idx;
}
}
*evbase = ctx->thr[thridx]->evbase;
*dnsbase = ctx->thr[thridx]->dnsbase;
ctx->thr[thridx]->load++;
pthread_mutex_unlock(&ctx->mutex);
#ifdef DEBUG_THREAD
log_dbg_printf("thridx: %d\n", thridx);
#endif /* DEBUG_THREAD */
return thridx;
}
/*
* Detach a connection from a thread by index.
* This function cannot fail.
*/
void
pxy_thrmgr_detach(pxy_thrmgr_ctx_t *ctx, int thridx)
{
pthread_mutex_lock(&ctx->mutex);
ctx->thr[thridx]->load--;
pthread_mutex_unlock(&ctx->mutex);
}
/* vim: set noet ft=c: */