/* * Ouroboros - Copyright (C) 2016 - 2020 * * A simple echo application * * Dimitri Staessens * Sander Vrijders * * 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. * * 3. Neither the name of the copyright holder nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "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 * COPYRIGHT HOLDER OR CONTRIBUTORS 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. */ #define _POSIX_C_SOURCE 199309L #include #include #include #define BUF_SIZE 256 static void usage(void) { printf("Usage: oecho [OPTION]...\n" "Sends an echo between a server and a client\n\n" " -l, --listen Run in server mode\n" " --help Display this help text and exit\n"); } static int server_main(void) { int fd = 0; char buf[BUF_SIZE]; ssize_t count = 0; printf("Starting the server.\n"); while (true) { fd = flow_accept(NULL, NULL); if (fd < 0) { printf("Failed to accept flow.\n"); break; } printf("New flow.\n"); count = flow_read(fd, &buf, BUF_SIZE); if (count < 0) { printf("Failed to read packet.\n"); flow_dealloc(fd); continue; } printf("Message from client is %.*s.\n", (int) count, buf); if (flow_write(fd, buf, count) == -1) { printf("Failed to write packet.\n"); flow_dealloc(fd); continue; } flow_dealloc(fd); } return 0; } static int client_main(void) { int fd = 0; char buf[BUF_SIZE]; char * message = "Client says hi!"; ssize_t count = 0; fd = flow_alloc("oecho", NULL, NULL); if (fd < 0) { printf("Failed to allocate flow.\n"); return -1; } if (flow_write(fd, message, strlen(message) + 1) < 0) { printf("Failed to write packet.\n"); flow_dealloc(fd); return -1; } count = flow_read(fd, buf, BUF_SIZE); if (count < 0) { printf("Failed to read packet.\n"); flow_dealloc(fd); return -1; } printf("Server replied with %.*s\n", (int) count, buf); flow_dealloc(fd); return 0; } int main(int argc, char ** argv) { int ret = -1; bool server = false; argc--; argv++; while (argc > 0) { if (strcmp(*argv, "-l") == 0 || strcmp(*argv, "--listen") == 0) { server = true; } else { usage(); return 0; } argc--; argv++; } if (server) ret = server_main(); else ret = client_main(); return ret; }