wolfssl-examples/dtls/client-dtls-threaded.c

279 lines
8.1 KiB
C

/*
* client-dtls-threaded.c
*
* Copyright (C) 2006-2024 wolfSSL Inc.
*
* This file is part of wolfSSL. (formerly known as CyaSSL)
*
* wolfSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfSSL 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*
*=============================================================================
*
* A simple dtls client with configurable threadpool, for
* instructional/learning purposes. Utilizes DTLS 1.2.
*/
#include <wolfssl/options.h>
#include <unistd.h>
#include <wolfssl/ssl.h>
#include <netdb.h>
#include <signal.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MSGLEN 4096
#define SERV_PORT 11111
#define DTLS_NUMTHREADS 16
typedef struct {
WOLFSSL * ssl;
int activefd;
WOLFSSL_CTX * ctx;
} thread_args_t;
static void safer_shutdown(thread_args_t * args);
static void * client_work(void * arg);
int
main(int argc,
char * argv[])
{
WOLFSSL_CTX * ctx = NULL; /* ctx shared by threads */
const char * certs = "../certs/ca-cert.pem";
int ret = 0;
int n_threads = 2;
pthread_t threads[DTLS_NUMTHREADS];
thread_args_t args[DTLS_NUMTHREADS];
int opt = 0;
memset(threads, 0, sizeof(threads));
memset(args, 0, sizeof(args));
while ((opt = getopt(argc, argv, "t:?")) != -1) {
switch (opt) {
case 't':
n_threads = atoi(optarg);
break;
case '?':
printf("usage:\n");
printf(" ./client-dtls-threaded [-t n]\n");
printf("\n");
printf("description:\n");
printf(" A simple dtls client with configurable threadpool.\n");
printf(" Num allowed threads is: 1 <= n <= %d\n",
DTLS_NUMTHREADS);
default:
return EXIT_FAILURE;
}
}
if (n_threads <= 0 || n_threads > DTLS_NUMTHREADS) {
printf("error: invalid n_threads: %d\n", n_threads);
return EXIT_FAILURE;
}
/* Initialize wolfSSL before assigning ctx */
wolfSSL_Init();
ctx = wolfSSL_CTX_new(wolfDTLSv1_2_client_method());
if (ctx == NULL) {
printf("error: wolfSSL_CTX_new failed\n");
return EXIT_FAILURE;
}
/* Load certificates into ctx variable */
ret = wolfSSL_CTX_load_verify_locations(ctx, certs, 0);
if (ret != SSL_SUCCESS) {
printf("error: loading %s failed, please check the file\n", certs);
return EXIT_FAILURE;
}
for (size_t i = 0; i < n_threads; ++i) {
args[i].ctx = ctx;
ret = pthread_create(&threads[i], NULL, client_work, &args[i]);
if (ret == 0 ) {
printf("info: spawned thread: %ld\n", (long)threads[i]);
}
else {
printf("error: pthread_create returned %d\n", ret);
threads[i] = 0;
}
}
for (size_t i = 0; i < n_threads; ++i) {
if (threads[i]) {
pthread_join(threads[i], NULL);
printf("info: joined thread: %ld\n", (long)threads[i]);
threads[i] = 0;
}
}
wolfSSL_CTX_free(ctx);
wolfSSL_Cleanup();
return EXIT_SUCCESS;
}
static void *
client_work(void * args)
{
thread_args_t * thread_args = (thread_args_t *) args;
int n_bytes = 0;
int err1;
struct sockaddr_in servAddr;
char send_msg[MSGLEN];
char recv_msg[MSGLEN];
int ret = 0;
const char * localhost_ip = "127.0.0.1";
/* Assign ssl variable */
thread_args->ssl = wolfSSL_new(thread_args->ctx);
if (thread_args->ssl == NULL) {
printf("error: wolfSSL_new failed\n");
return NULL;
}
/* servAddr setup */
memset(&servAddr, 0, sizeof(servAddr));
servAddr.sin_family = AF_INET;
servAddr.sin_port = htons(SERV_PORT);
ret = inet_pton(AF_INET, localhost_ip, &servAddr.sin_addr);
if (ret != 1) {
printf("error: inet_pton %s returned %d\n", localhost_ip, ret);
return NULL;
}
ret = wolfSSL_dtls_set_peer(thread_args->ssl, &servAddr, sizeof(servAddr));
if (ret != SSL_SUCCESS) {
printf("error: wolfSSL_dtls_set_peer returned %d\n", ret);
return NULL;
}
thread_args->activefd = socket(AF_INET, SOCK_DGRAM, 0);
if (thread_args->activefd <= 0) {
printf("error: socket returned %d\n", thread_args->activefd);
return NULL;
}
printf("info: opened socket: %d\n", thread_args->activefd);
/* Set the file descriptor for ssl and connect with ssl variable */
wolfSSL_set_fd(thread_args->ssl, thread_args->activefd);
if (wolfSSL_connect(thread_args->ssl) != SSL_SUCCESS) {
err1 = wolfSSL_get_error(thread_args->ssl, 0);
printf("error: thread %ld: wolfSSL_connect returned = %d, %s\n",
(long)pthread_self(), err1,
wolfSSL_ERR_reason_error_string(err1));
return NULL;
}
/* Simulate a simple protocol over DTLS that exchanges a
* sequence of records, and checks we get correct records
* from correct server threads. */
long int server_tid = 0;
const char * tid_str = NULL; /* Str to thread id in response. */
for (size_t i = 0; i < 4; ++i) {
memset(send_msg, '\0', sizeof(send_msg));
memset(recv_msg, '\0', sizeof(recv_msg));
char seq = '0' + (int) i;
sprintf(send_msg, "msg %zu from client thread %ld\n", i,
(long)pthread_self());
n_bytes = wolfSSL_write(thread_args->ssl, send_msg, strlen(send_msg));
if (n_bytes != strlen(send_msg)) {
printf("error: wolfSSL_write returned %d", n_bytes);
break;
}
/* n is the # of bytes received */
n_bytes = wolfSSL_read(thread_args->ssl, recv_msg, sizeof(recv_msg)-1);
if (n_bytes < 0) {
printf("error: wolfSSL_read returned %d", n_bytes);
break;
}
recv_msg[n_bytes] = '\0';
fputs(recv_msg, stdout);
/* Check the server replied with the correct sequence record, e.g.:
* "msg 2 from server thread 140146322425536" */
if (recv_msg[4] != seq) {
printf("error: got msg %c, expected %c\n", recv_msg[4], seq);
break;
}
tid_str = &recv_msg[25];
if (server_tid == 0) {
/* Save the server thread id on message 0. */
server_tid = atol(tid_str);
}
else {
/* Compare saved thread id. */
if (server_tid != atol(tid_str)) {
printf("error: got rsp from server thread %ld, expected %ld\n",
server_tid, atol(tid_str));
break;
}
else {
printf("info: got response from server thread %ld\n",
server_tid);
}
}
sleep(1);
}
safer_shutdown(thread_args);
return NULL;
}
/* Small shutdown wrapper to safely clean up a thread's
* connection. */
static void
safer_shutdown(thread_args_t * args)
{
if (args == NULL) {
printf("error: safer_shutdown with null args\n");
return;
}
if (args->ssl != NULL) {
printf("info: closed tls session: %p\n", (void*) args->ssl);
wolfSSL_shutdown(args->ssl);
wolfSSL_free(args->ssl);
args->ssl = NULL;
}
if (args->activefd > 0) {
printf("info: closed socket: %d\n", args->activefd);
close(args->activefd);
args->activefd = 0;
}
return;
}