/* 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 "ddcd.h" #define SOFTWARE_NAME "ddcd" #define MSG_START SOFTWARE_NAME ": " int host_port = 0; char host_address[100] = "127.0.0.1"; int decimation = 0; float transition_bw = 0.05; int bufsize = 1024; int bufsizeall; int pipe_max_size; int in_client = 0; char ddc_method_str[100] = "td"; ddc_method_t ddc_method; pid_t main_dsp_proc; pid_t pgrp; int input_fd = STDIN_FILENO; //can be stdin, or the stdout of main_subprocess pid_t main_subprocess_pid = 0; char* buf; 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; } int proc_exists(pid_t pid) { if(pid==0 || pid==1) return 1; return kill(pid, 0) != -1; } void sig_handler(int signo) { int tmpstat; if(signo==SIGCHLD) if( main_subprocess_pid && signo==SIGCHLD && (waitpid(main_subprocess_pid, &tmpstat, WNOHANG), 1) && !proc_exists(main_subprocess_pid) ) { fprintf(stderr,MSG_START "main_subprocess_pid exited! Exiting...\n"); } else return; if(pgrp!=1 && pgrp!=0) //I just want to make sure that we cannot kill init or sched killpg(pgrp, signo); fprintf(stderr, MSG_START "signal %d caught in %s, exiting ddcd...\n", signo, (in_client)?"client":"main"); fflush(stderr); exit(0); } client_t* this_client; int main(int argc, char* argv[]) { int c; fd_set select_fds; for(;;) { int option_index = 0; static struct option long_options[] = { {"port", required_argument, 0, 'p' }, {"address", required_argument, 0, 'a' }, {"decimation", required_argument, 0, 'd' }, {"bufsize", required_argument, 0, 'b' }, {"method", required_argument, 0, 'm' }, {"transition", required_argument, 0, 't' } }; c = getopt_long(argc, argv, "p:a:d:b:m:t:", long_options, &option_index); if(c==-1) break; switch (c) { case 'a': host_address[100-1]=0; strncpy(host_address,optarg,100-1); break; case 'p': host_port=atoi(optarg); break; case 'd': decimation=atoi(optarg); break; case 'b': bufsize=atoi(optarg); break; case 'm': ddc_method_str[100-1]=0; strncpy(ddc_method_str,optarg,100-1); break; case 't': sscanf(optarg,"%g",&transition_bw); break; case 0: case '?': case ':': default:; print_exit(MSG_START "error in getopt_long()\n"); } } if(!decimation) print_exit(MSG_START "missing required command line argument, --decimation.\n"); if(!host_port) print_exit(MSG_START "missing required command line argument, --port.\n"); if(decimation<0) print_exit(MSG_START "invalid value for --decimation (should be >0).\n"); if(decimation==1) fprintf(stderr, MSG_START "decimation = 1, just copying raw samples.\n"); if(transition_bw<0||transition_bw>0.5) print_exit(MSG_START "invalid value for --transition (should be between 0 and 0.5).\n"); if(decimation==1); //don't do anything then else if(!strcmp(ddc_method_str,"td")) { ddc_method = M_TD; fprintf(stderr, MSG_START "method is M_TD (default).\n"); } else if (!strcmp(ddc_method_str,"fastddc")) { ddc_method = M_FASTDDC; fprintf(stderr, MSG_START "method is M_FASTDDC.\n"); } else print_exit(MSG_START "invalid parameter given to --method.\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); sigaction(SIGCHLD, &sa, NULL); //sigaction(SIGPIPE, &sa, NULL); prctl(PR_SET_PDEATHSIG, SIGHUP); //get a signal when parent exits 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; bufsizeall = bufsize*sizeof(char); buf = (char*)malloc(bufsizeall); FILE* tempfile = fopen("/proc/sys/fs/pipe-max-size","r"); if(!tempfile) { perror(MSG_START "cannot read /proc/sys/fs/pipe-max-size"); } else { char pipe_max_size_str[100]; int tfread = fread(pipe_max_size_str, 1, 100, tempfile); pipe_max_size_str[tfread]='\0'; pipe_max_size = atoi(pipe_max_size_str); //fprintf(stderr, MSG_START "note: pipe_max_size = %d\n", pipe_max_size); //if(pipe_max_size>4096 && fcntl(STDIN_FILENO, F_SETPIPE_SZ, pipe_max_size)==-1) // perror("failed to fcntl(STDIN_FILENO, F_SETPIPE_SZ, ...)"); } //We'll see if it is a good idea: setpgrp(); pgrp = getpgrp(); //Start DSP subprocess from the main process if required char main_subprocess_cmd_buf[500]; int pipe_m2s_ctl[2]; //main to subprocess :: control channel int pipe_s2m[2]; //subprocess to main if(pipe(pipe_m2s_ctl)) error_exit(MSG_START "couldn't create pipe_m2s_ctl"); if(pipe(pipe_s2m)) error_exit(MSG_START "couldn't create pipe_s2m"); if(decimation!=1) { switch(ddc_method) { case M_TD: break; case M_FASTDDC: sprintf(main_subprocess_cmd_buf, subprocess_args_fastddc_1, decimation, transition_bw); fprintf(stderr, MSG_START "starting main_subprocess_cmd: %s\n", main_subprocess_cmd_buf); if(!(main_subprocess_pid = run_subprocess( main_subprocess_cmd_buf, 0, pipe_s2m ))) print_exit(MSG_START "couldn't start main_subprocess_cmd!\n"); close(STDIN_FILENO); // redirect stdin to the stdin of the subprocess break; } } int highfd = 0; FD_ZERO(&select_fds); FD_SET(listen_socket, &select_fds); maxfd(&highfd, listen_socket); if(main_subprocess_pid) input_fd = pipe_s2m[0]; //else STDIN_FILENO 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)) //don't do it before subprocess fork! error_exit(MSG_START "cannot set_nonblocking()"); for(;;) { //Let's wait until there is any new data to read, or any new connection! select(highfd, &select_fds, NULL, NULL, NULL); //Is there a new client connection? if( (new_socket = accept(listen_socket, (struct sockaddr*)&addr_cli, &addr_cli_len)) != -1) { this_client = new client_t; this_client->error = 0; memcpy(&this_client->addr, &addr_cli, sizeof(this_client->addr)); this_client->socket = new_socket; if(pipe(this_client->pipefd) == -1) { perror(MSG_START "cannot open new pipe() for the client"); continue; } if(fcntl(this_client->pipefd[1], F_SETPIPE_SZ, pipe_max_size) == -1) perror("failed to F_SETPIPE_SZ for the client pipe"); if(this_client->pid = fork()) { //We're the parent set_nonblocking(this_client->pipefd[1]); clients.push_back(this_client); fprintf(stderr, MSG_START "client pid: %d\n", this_client->pid); } else { //We're the client client(); return 1; } } int retval = read(input_fd, buf, bufsizeall); if(retval==0) { //end of input stream, close clients and exit } else if(retval != -1) { for (int i=0; ipipefd[1], buf, retval)==-1) { if(!clients[i]->error) { print_client(clients[i], "lost buffer, failed to write pipe."); clients[i]->error=1; } //fprintf(stderr, MSG_START "errno is %d\n", errno); //usually 11 //int wpstatus; //int wpresult = waitpid(clients[i]->pid, &wpstatus, WNOHANG); //fprintf(stderr, MSG_START "pid is %d\n",clients[i]->pid); //perror("somethings wrong"); //if(wpresult == -1) print_client(clients[i], "error while waitpid()!"); //else if(wpresult == 0) waitpid(clients[i]->pid, NULL, WNOHANG); if(!proc_exists(clients[i]->pid)) { //Client exited! print_client(clients[i], "closing client from main process."); close(clients[i]->pipefd[1]); close(clients[i]->socket); delete clients[i]; clients.erase(clients.begin()+i); print_client(clients[i], "done closing client from main process."); } } else { if(clients[i]->error) print_client(clients[i], "pipe okay again."); clients[i]->error=0; } } } //TODO: at the end, server closes pipefd[1] for client } return 0; } pid_t run_subprocess(char* cmd, int* pipe_in, int* pipe_out) { pid_t pid = fork(); //fprintf(stderr, "run_subprocess :: fork-ed %d\n", pid); if(pid < 0) return 0; //fork failed if(pid == 0) { //We're the subprocess //fprintf(stderr, "run_subprocess :: execl\n"); //if(fcntl(pipe_in[1], F_SETPIPE_SZ, pipe_max_size) == -1) perror("Failed to F_SETPIPE_SZ in run_subprocess()"); if(pipe_in) { close(pipe_in[1]); dup2(pipe_in[0], STDIN_FILENO); } if(pipe_out) { close(pipe_out[0]); dup2(pipe_out[1], STDOUT_FILENO); } execl("/bin/bash","bash","-c",cmd, (char*)0); error_exit(MSG_START "run_subprocess failed to execute command"); } else return pid; } void print_client(client_t* client, const char* what) { fprintf(stderr,MSG_START "(client %s:%d) %s\n", inet_ntoa(client->addr.sin_addr), client->addr.sin_port, what); } void client_cleanup() { close(this_client->pipefd[0]); } void client() { in_client=1; print_client(this_client, "client process forked."); char client_subprocess_cmd_buf[500]; pid_t client_subprocess_pid = 0; int input_fd = this_client->pipefd[0]; prctl(PR_SET_PDEATHSIG, SIGHUP); //get a signal when parent exits if(decimation!=1) { int pipe_ctl[2], pipe_stdout[2]; if(pipe(pipe_ctl)==-1) error_exit(MSG_START "cannot open new pipe() for the client subprocess"); if(pipe(pipe_stdout)==-1) error_exit(MSG_START "cannot open new pipe() for the client subprocess"); switch(ddc_method) { case M_TD: sprintf(client_subprocess_cmd_buf, subprocess_cmd_td, pipe_ctl[0], decimation, transition_bw); break; case M_FASTDDC: sprintf(client_subprocess_cmd_buf, subprocess_args_fastddc_2, decimation, pipe_ctl[0], transition_bw); break; } if(!(client_subprocess_pid = run_subprocess( client_subprocess_cmd_buf, this_client->pipefd, pipe_stdout ))) print_exit(MSG_START "couldn't start client_subprocess_cmd!\n"); fprintf(stderr, MSG_START "starting client_subprocess_cmd: %s\n", client_subprocess_cmd_buf); input_fd = pipe_stdout[0]; //we don't have to set it nonblocking fprintf(stderr, MSG_START "pipe_stdout[0] = %d\n", pipe_stdout[0]); setpgrp(); pgrp = getpgrp(); } for(;;) { read(input_fd,buf,bufsizeall); if(send(this_client->socket,buf,bufsizeall,0)==-1) { print_client(this_client, "client process is exiting."); if(client_subprocess_pid && pgrp!=1 && pgrp!=0) killpg(pgrp, SIGTERM); exit(0); } } } void error_exit(const char* why) { perror(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; }