DTLS threaded read-write with same SSL object

.gitignore

@@ -51,12 +51,14 @@ android/wolfssljni-ndk-sample/proguard-project.txt
 /dtls/client-dtls-ipv6
 /dtls/client-dtls-nonblocking
 /dtls/client-dtls-resume
+/dtls/client-dtls-rw-threads
 /dtls/client-dtls-shared
 /dtls/client-dtls
 /dtls/client-udp
 /dtls/server-dtls-callback
 /dtls/server-dtls-ipv6
 /dtls/server-dtls-nonblocking
+/dtls/server-dtls-rw-threads
 /dtls/server-dtls-threaded
 /dtls/server-dtls
 /dtls/server-udp

dtls/client-dtls-rw-threads.c

@@ -0,0 +1,255 @@
+/*
+ * client-dtls.c
+ *
+ * Copyright (C) 2006-2020 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
+ *
+ *=============================================================================
+ *
+ * Bare-bones example of a DTLS client for instructional/learning purposes.
+ */
+
+#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>
+#include <pthread.h>
+
+#include <sys/time.h>
+
+/* WARNING: This function is not portable. */
+static WC_INLINE double current_time(int reset)
+{
+    struct timeval tv;
+    gettimeofday(&tv, 0);
+    (void)reset;
+
+    return (double)tv.tv_sec + (double)tv.tv_usec / 1000000;
+}
+
+#define SERV_PORT 11111
+
+typedef struct {
+    int size;       /* Size of buffer to read. */
+    WOLFSSL* ssl;   /* SSL object to use. */
+} threadArgs;
+
+static int cleanup;             /* To handle shutdown */
+static int minRunTime = 1;      /* Minimum run time. Default: 1 second */
+
+/* Reader thread.
+ *
+ * Only started after handshake complete.
+ */
+void* Reader(void* openSock)
+{
+    threadArgs* args = (threadArgs*)openSock;
+    int                recvLen = 0;                /* length of message     */
+    int                msgLen = args->size;        /* the size of message   */
+    unsigned char      buff[msgLen];               /* the incoming message  */
+    WOLFSSL*           ssl = args->ssl;
+    int                result;
+    fd_set             recvfds, errfds;
+    struct timeval     timeout;
+    int                currTimeout;
+    int                nb_sockfd;
+    int                nfds;
+
+    nb_sockfd = (int) wolfSSL_get_fd(ssl);
+
+    printf("Reading\n");
+
+    while (!cleanup) { 
+        currTimeout = wolfSSL_dtls_get_current_timeout(ssl);
+        nfds = nb_sockfd + 1;
+        timeout = (struct timeval) { (currTimeout > 0) ? currTimeout : 0, 0};
+
+        /* Setup file descriptor list to monitor. */
+        FD_ZERO(&recvfds);
+        FD_SET(nb_sockfd, &recvfds);
+        FD_ZERO(&errfds);
+        FD_SET(nb_sockfd, &errfds);
+
+        result = select(nfds, &recvfds, NULL, &errfds, &timeout);
+        if ((result > 0) && FD_ISSET(nb_sockfd, &errfds)) {
+            /* Tell other thread to cleanup. */
+            cleanup = 1;
+            /* Finished reading. */
+            break;
+        }
+
+        /* If data waiting on receive file descriptor, read it. */
+        if (result > 0 && FD_ISSET(nb_sockfd, &recvfds)) {
+            /* Read application data. */
+            if ((recvLen = wolfSSL_read(ssl, buff, msgLen-1)) < 0) {
+                /* Handle errors. */
+                int readErr = wolfSSL_get_error(ssl, 0);
+                if (readErr != SSL_ERROR_WANT_READ) {
+                    printf("SSL_read failed.\n");
+                    /* Tell other threads to cleanup. */
+                    cleanup = 1;
+                    break;
+                }
+            }
+        }
+    }
+
+    return NULL;
+}
+
+void* Writer(void* openSock)
+{
+    threadArgs* args = (threadArgs*)openSock;
+    char        ack[] = "I hear you fashizzle!\n";
+    WOLFSSL*    ssl = args->ssl;
+    double      start = current_time(0);
+
+    printf("Writing\n");
+
+    /* Keep writing while not in cleanup. */
+    while (!cleanup) {
+        /* Write message and check for error. */
+        if (wolfSSL_write(ssl, ack, sizeof(ack)) < 0) {
+            printf("wolfSSL_write fail.\n");
+            /* Tell other threads to cleanup. */
+            cleanup = 1;
+            break;
+        }
+
+        /* Stop writing after a minimum run time. */
+        if (current_time(0) > start + minRunTime) {
+            printf("wolfSSL_write done.\n");
+            cleanup = 1;
+            break;
+        }
+    }
+
+    return NULL;
+}
+
+int main (int argc, char** argv)
+{
+    /* standard variables used in a dtls client*/
+    int             n = 0;
+    int             sockfd = 0;
+    int             err1;
+    struct          sockaddr_in servAddr;
+    WOLFSSL*        ssl = 0;
+    WOLFSSL_CTX*    ctx = 0;
+    char            cert_array[]  = "certs/ca-cert.pem";
+    char*           certs = cert_array;
+    threadArgs      args;
+    pthread_t       threadidReader;
+    pthread_t       threadidWriter;
+
+    /* Program argument checking */
+    if (argc < 2 || argc > 3) {
+        printf("usage: udpcli <IP address> [<min time>]\n");
+        return 1;
+    }
+
+    if (argc == 3) {
+        minRunTime = atoi(argv[2]);
+    }
+
+    /* Initialize wolfSSL before assigning ctx */
+    wolfSSL_Init();
+    wolfSSL_Debugging_ON();
+
+    /* wolfSSL_Debugging_ON(); */
+
+    if ( (ctx = wolfSSL_CTX_new(wolfDTLSv1_2_client_method())) == NULL) {
+        fprintf(stderr, "wolfSSL_CTX_new error.\n");
+        return 1;
+    }
+
+    /* Load certificates into ctx variable */
+    if (wolfSSL_CTX_load_verify_locations(ctx, certs, 0)
+            != SSL_SUCCESS) {
+        fprintf(stderr, "Error loading %s, please check the file.\n", certs);
+        return 1;
+    }
+
+    /* Assign ssl variable */
+    ssl = wolfSSL_new(ctx);
+    if (ssl == NULL) {
+        printf("unable to get ssl object");
+        return 1;
+    }
+
+    /* servAddr setup */
+    memset(&servAddr, 0, sizeof(servAddr));
+    servAddr.sin_family = AF_INET;
+    servAddr.sin_port = htons(SERV_PORT);
+    if (inet_pton(AF_INET, argv[1], &servAddr.sin_addr) < 1) {
+        printf("Error and/or invalid IP address\n");
+        return 1;
+    }
+
+    wolfSSL_dtls_set_peer(ssl, &servAddr, sizeof(servAddr));
+
+    if ( (sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+       printf("cannot create a socket.\n");
+       return 1;
+    }
+
+    /* Set the file descriptor for ssl and connect with ssl variable */
+    wolfSSL_set_fd(ssl, sockfd);
+    wolfSSL_dtls_set_using_nonblock(ssl, 1);
+    fcntl(sockfd, F_SETFL, O_NONBLOCK);
+
+    while (wolfSSL_connect(ssl) != SSL_SUCCESS) {
+        err1 = wolfSSL_get_error(ssl, 0);
+        if (err1 != SSL_ERROR_WANT_READ && err1 != SSL_ERROR_WANT_WRITE) {
+            printf("err = %d, %s\n", err1,
+                wolfSSL_ERR_reason_error_string(err1));
+            printf("SSL_connect failed\n");
+            return 1;
+        }
+    }
+
+    cleanup = 0;
+    args.size = 256;
+    args.ssl = ssl;
+
+    fcntl(wolfSSL_get_fd(ssl), F_SETFL, O_NONBLOCK);
+
+    /* Create reader and writer threads. */
+    pthread_create(&threadidReader, NULL, Reader, &args);
+    pthread_create(&threadidWriter, NULL, Writer, &args);
+
+    /* Wait for read/write threads to be done. */
+    pthread_join(threadidReader, NULL);
+    pthread_join(threadidWriter, NULL);
+
+    /* Housekeeping */
+    wolfSSL_shutdown(ssl);
+    wolfSSL_free(ssl);
+    close(sockfd);
+    wolfSSL_CTX_free(ctx);
+    wolfSSL_Cleanup();
+
+    return 0;
+}