/* This software is part of libcsdr, a set of simple DSP routines for Software Defined Radio. Copyright (c) 2014, Andras Retzler All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * 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. * 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 ANDRAS RETZLER 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 "nmux.h" char help_text[]="nmux is a TCP stream multiplexer. It reads data from the standard input, and sends it to each client connected through TCP sockets. Available command line options are:\n" "\t--port (-p), --address (-a): TCP port and address to listen.\n" "\t--bufsize (-b), --bufcnt (-n): Internal buffer size and count.\n" "\t--help (-h): Show this message.\n"; int host_port = 0; char host_address[100] = "127.0.0.1"; int thread_cntr = 0; //CLI parameters int bufsize = 1024; int bufcnt = 1024; char** global_argv; int global_argc; tsmpool* pool; void sig_handler(int signo) { fprintf(stderr, MSG_START "signal %d caught, exiting...\n", signo); fflush(stderr); exit(0); } int main(int argc, char* argv[]) { global_argv = argv; global_argc = argc; int c; int no_options = 1; for(;;) { int option_index = 0; static struct option long_options[] = { {"port", required_argument, 0, 'p' }, {"address", required_argument, 0, 'a' }, {"bufsize", required_argument, 0, 'b' }, {"bufcnt", required_argument, 0, 'n' }, {"help", no_argument, 0, 'h' }, {0, 0, 0, 0 } }; c = getopt_long(argc, argv, "p:a:b:n:h", long_options, &option_index); if(c==-1) break; no_options = 0; switch (c) { case 'a': host_address[100-1]=0; strncpy(host_address,optarg,100-1); break; case 'p': host_port=atoi(optarg); break; case 'b': bufsize=atoi(optarg); break; case 'n': bufcnt=atoi(optarg); break; case 'h': print_exit(help_text); break; case 0: case '?': case ':': default: print_exit(MSG_START "error in getopt_long()\n"); } } if(no_options) print_exit(help_text); if(!host_port) print_exit(MSG_START "missing required command line argument, --port.\n"); if(bufsize<0) print_exit(MSG_START "invalid value for --bufsize (should be >0)\n"); if(bufcnt<0) print_exit(MSG_START "invalid value for --bufcnt (should be >0)\n"); //set signals struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = sig_handler; sigaction(SIGTERM, &sa, NULL); sigaction(SIGKILL, &sa, NULL); sigaction(SIGQUIT, &sa, NULL); sigaction(SIGINT, &sa, NULL); sigaction(SIGHUP, &sa, NULL); struct sockaddr_in addr_host; int listen_socket; std::vector clients; clients.reserve(100); listen_socket=socket(AF_INET,SOCK_STREAM,0); int sockopt = 1; if( setsockopt(listen_socket, SOL_SOCKET, SO_REUSEADDR, (char *)&sockopt, sizeof(sockopt)) == -1 ) error_exit(MSG_START "cannot set SO_REUSEADDR"); //the best description on SO_REUSEADDR ever: http://stackoverflow.com/a/14388707/3182453 memset(&addr_host,'0',sizeof(addr_host)); addr_host.sin_family = AF_INET; addr_host.sin_port = htons(host_port); addr_host.sin_addr.s_addr = INADDR_ANY; if( (addr_host.sin_addr.s_addr=inet_addr(host_address)) == INADDR_NONE ) error_exit(MSG_START "invalid host address"); if( bind(listen_socket, (struct sockaddr*) &addr_host, sizeof(addr_host)) < 0 ) error_exit(MSG_START "cannot bind() address to the socket"); if( listen(listen_socket, 10) == -1 ) error_exit(MSG_START "cannot listen() on socket"); fprintf(stderr, MSG_START "listening on %s:%d\n", inet_ntoa(addr_host.sin_addr), host_port); struct sockaddr_in addr_cli; socklen_t addr_cli_len = sizeof(addr_cli); int new_socket; int highfd = 0; int input_fd = STDIN_FILENO; fd_set select_fds; FD_ZERO(&select_fds); FD_SET(listen_socket, &select_fds); maxfd(&highfd, listen_socket); FD_SET(input_fd, &select_fds); maxfd(&highfd, input_fd); //Set stdin and listen_socket to non-blocking if(set_nonblocking(input_fd) || set_nonblocking(listen_socket)) error_exit(MSG_START "cannot set_nonblocking()"); //Create tsmpool pool = new tsmpool(bufsize, bufcnt); if(!pool->is_ok()) print_exit(MSG_START "tsmpool failed to initialize\n"); unsigned char* current_write_buffer = (unsigned char*)pool->get_write_buffer(); int index_in_current_write_buffer = 0; //Create wait condition: client threads waiting for input data from the main thread will be // waiting on this condition. They will be woken up with pthread_cond_broadcast() if new // data arrives. pthread_cond_t* wait_condition = new pthread_cond_t; if(pthread_cond_init(wait_condition, NULL)) print_exit(MSG_START "pthread_cond_init failed"); //cond_attrs is ignored by Linux for(;;) { if(NMUX_DEBUG) fprintf(stderr, "mainfor: selecting..."); //Let's wait until there is any new data to read, or any new connection! select(highfd, &select_fds, NULL, NULL, NULL); if(NMUX_DEBUG) fprintf(stderr, "selected.\n"); //Is there a new client connection? if( (new_socket = accept(listen_socket, (struct sockaddr*)&addr_cli, &addr_cli_len)) != -1) { if(NMUX_DEBUG) fprintf(stderr, "mainfor: accepted (%d).\n", new_socket); //Close all finished clients for(int i=0;istatus == CS_THREAD_FINISHED) { if(NMUX_DEBUG) fprintf(stderr, "mainfor: client removed: %d\n", i); client_erase(clients[i]); clients.erase(clients.begin()+i); } } //We're the parent, let's create a new client and initialize it client_t* new_client = new client_t; new_client->error = 0; memcpy(&new_client->addr, &addr_cli, sizeof(struct sockaddr_in)); new_client->socket = new_socket; new_client->status = CS_CREATED; new_client->tsmthread = pool->register_thread(); new_client->lpool = pool; pthread_mutex_init(&new_client->wait_mutex, NULL); new_client->wait_condition = wait_condition; new_client->sleeping = 0; if(pthread_create(&new_client->thread, NULL, client_thread, (void*)&new_client)==0) { clients.push_back(new_client); fprintf(stderr, MSG_START "pthread_create() done, clients now: %d\n", clients.size()); } else { fprintf(stderr, MSG_START "pthread_create() failed.\n"); pool->remove_thread(new_client->tsmthread); pthread_mutex_destroy(&new_client->wait_mutex); delete new_client; } } if(index_in_current_write_buffer >= bufsize) { current_write_buffer = (unsigned char*)pool->get_write_buffer(); pthread_cond_broadcast(wait_condition); //Shouldn't we do it after we put data in? // No, on get_write_buffer() actually the previous buffer is getting available // for read for threads that wait for new data (wait on pthead mutex // client->wait_condition). index_in_current_write_buffer = 0; } int retval = read(input_fd, current_write_buffer + index_in_current_write_buffer, bufsize - index_in_current_write_buffer); if(NMUX_DEBUG) fprintf(stderr, "mainfor: read %d\n", retval); if(retval>0) { index_in_current_write_buffer += retval; } else if(retval==0) { //End of input stream, close clients and exit print_exit(MSG_START "(main thread/for) end input stream, exiting.\n"); } else if(retval==-1) { error_exit(MSG_START "(main thread/for) error in read(), exiting.\n"); } } } void client_erase(client_t* client) { pthread_mutex_destroy(&client->wait_mutex); pthread_cond_destroy(client->wait_condition); pool->remove_thread(client->tsmthread); } void* client_thread (void* param) { fprintf(stderr, "client 0x%x: started!\n", (unsigned)param); client_t* this_client = (client_t*)param; this_client->status = CS_THREAD_RUNNING; int retval; tsmpool* lpool = this_client->lpool; if(NMUX_DEBUG) fprintf(stderr, "client 0x%x: socket = %d!\n", (unsigned)param, this_client->socket); if(NMUX_DEBUG) fprintf(stderr, "client 0x%x: poll init...", (unsigned)param); struct pollfd pollfds[1]; pollfds[0].fd = this_client->socket; pollfds[0].events = POLLOUT; pollfds[0].revents = 0; if(NMUX_DEBUG) fprintf(stderr, "done.\n"); //Set this_client->socket to non-blocking if(set_nonblocking(this_client->socket)) error_exit(MSG_START "cannot set_nonblocking() on this_client->socket"); int client_buffer_index = 0; int client_goto_source = 0; char* pool_read_buffer = NULL; for(;;) { //Wait until there is any data to send. // If I haven't sent all the data from my last buffer, don't wait. // (Wait for the server process to wake me up.) while(!pool_read_buffer || client_buffer_index >= lpool->size) { if(NMUX_DEBUG) fprintf(stderr, "client 0x%x: cond_waiting for more data\n", (unsigned)param); char* pool_read_buffer = (char*)lpool->get_read_buffer(this_client->tsmthread); pthread_mutex_lock(&this_client->wait_mutex); this_client->sleeping = 1; pthread_cond_wait(this_client->wait_condition, &this_client->wait_mutex); } //Wait for the socket to be available for write. if(NMUX_DEBUG) fprintf(stderr, "client 0x%x: polling for socket write...", (unsigned)param); int ret = poll(pollfds, 1, -1); if(NMUX_DEBUG) fprintf(stderr, "done.\n"); if(ret == 0) continue; else if (ret == -1) { client_goto_source = 1; goto client_thread_exit; } //Read data from global tsmpool and write it to client socket if(NMUX_DEBUG) fprintf(stderr, "client 0x%x: sending...", (unsigned)param); ret = send(this_client->socket, pool_read_buffer + client_buffer_index, lpool->size - client_buffer_index, 0); if(NMUX_DEBUG) fprintf(stderr, "done.\n"); if(ret == -1) { switch(errno) { case EAGAIN: break; default: client_goto_source = 2; goto client_thread_exit; } } else client_buffer_index += ret; } client_thread_exit: this_client->status = CS_THREAD_FINISHED; fprintf(stderr, "client 0x%x: CS_THREAD_FINISHED, client_goto_source = %d, errno = %d", (unsigned)param, client_goto_source, errno); pthread_exit(NULL); return NULL; } int set_nonblocking(int fd) { int flagtmp; if((flagtmp = fcntl(fd, F_GETFL))!=-1) if((flagtmp = fcntl(fd, F_SETFL, flagtmp|O_NONBLOCK))!=-1) return 0; return 1; } void error_exit(const char* why) { perror(why); //do we need a \n at the end of (why)? exit(1); } void print_exit(const char* why) { fprintf(stderr, "%s", why); exit(1); } void maxfd(int* maxfd, int fd) { if(fd>=*maxfd) *maxfd=fd+1; }