mdw@git.distorted.org.uk Git - disorder/blob - disobedience/rtp.c

   1 /*
   2  * This file is part of Disobedience
   3  * Copyright (C) 2007-2010 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file disobedience/rtp.c
  19  * @brief RTP player support for Disobedience
  20  */
  21
  22 #include "disobedience.h"
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <sys/un.h>
  28 #include <sys/utsname.h>
  29 #include <sys/wait.h>
  30
  31 /** @brief Path to RTP player's control socket */
  32 static char *rtp_socket;
  33
  34 /** @brief Path to RTP player's logfile */
  35 static char *rtp_log;
  36
  37 /** @brief Initialize @ref rtp_socket and @ref rtp_log if necessary */
  38 static void rtp_init(void) {
  39   if(!rtp_socket) {
  40     const char *home = getenv("HOME");
  41     char *dir, *base;
  42     struct utsname uts;
  43
  44     byte_xasprintf(&dir, "%s/.disorder/", home);
  45     mkdir(dir, 02700);
  46     if(uname(&uts) < 0)
  47       byte_xasprintf(&base, "%s/", dir);
  48     else
  49       byte_xasprintf(&base, "%s/%s-", dir, uts.nodename);
  50     byte_xasprintf(&rtp_socket, "%srtp", base);
  51     byte_xasprintf(&rtp_log, "%srtp.log", base);
  52   }
  53 }
  54
  55 /** @brief Return a connection to the RTP player's control socket */
  56 static FILE *rtp_connect(void) {
  57   struct sockaddr_un un;
  58   int fd;
  59   FILE *fp;
  60
  61   rtp_init();
  62   memset(&un, 0, sizeof un);
  63   un.sun_family = AF_UNIX;
  64   strcpy(un.sun_path, rtp_socket);
  65   fd = xsocket(PF_UNIX, SOCK_STREAM, 0);
  66   if(connect(fd, (const struct sockaddr *)&un, sizeof un) < 0) {
  67     /* Connection refused just means that the player quit without deleting its
  68      * socket */
  69     switch(errno) {
  70     case ECONNREFUSED:
  71     case ENOENT:
  72       break;
  73     default:
  74       /* Anything else may be a problem */
  75       fpopup_msg(GTK_MESSAGE_ERROR, "connecting to %s: %s",
  76                  rtp_socket, strerror(errno));
  77       break;
  78     }
  79     close(fd);
  80     return 0;
  81   }
  82   if(!(fp = fdopen(fd, "r+"))) {
  83     fpopup_msg(GTK_MESSAGE_ERROR, "error calling fdopen: %s", strerror(errno));
  84     close(fd);
  85     return 0;
  86   }
  87   return fp;
  88 }
  89
  90 /** @brief Return non-0 iff the RTP player is running */
  91 int rtp_running(void) {
  92   FILE *fp = rtp_connect();
  93
  94   if(!fp)
  95     return 0;                           /* no connection -> not running */
  96   fclose(fp);                           /* connection -> running */
  97   return 1;
  98 }
  99
 100 int rtp_getvol(int *l, int *r) {
 101   FILE *fp;
 102   int rc = -1;
 103
 104   fp = rtp_connect(); if(!fp) goto end;
 105   fprintf(fp, "getvol\n"); fflush(fp);
 106   if(fscanf(fp, "%d %d\n", l, r) != 2) goto end;
 107   rc = 0;
 108 end:
 109   if(fp) fclose(fp);
 110   return rc;
 111 }
 112
 113 int rtp_setvol(int *l, int *r) {
 114   FILE *fp = rtp_connect(); if(!fp) return -1;
 115   fprintf(fp, "setvol %d %d\n", *l, *r); fflush(fp);
 116   if(fscanf(fp, "%d %d\n", l, r) != 2) { /* do nothing */ }
 117   fclose(fp);
 118   return 0;
 119 }
 120
 121 /** @brief Activate the RTP player if it is not running */
 122 void start_rtp(void) {
 123   pid_t pid;
 124   int w, fd;
 125
 126   if(rtp_running())
 127     return;                             /* already running */
 128   /* double-fork so we don't have to wait() later */
 129   if(!(pid = xfork())) {
 130     if(setsid() < 0)
 131       disorder_fatal(errno, "error calling setsid");
 132     if(!xfork()) {
 133       /* grandchild */
 134       exitfn = _exit;
 135       /* log errors and output somewhere reasonably sane.  rtp_running()
 136        * will have made sure the directory exists. */
 137       if((fd = open(rtp_log, O_WRONLY|O_CREAT|O_TRUNC, 0600)) < 0)
 138         disorder_fatal(errno, "creating %s", rtp_log);
 139       if(dup2(fd, 1) < 0
 140          || dup2(fd, 2) < 0)
 141         disorder_fatal(errno, "dup2");
 142       if(close(fd) < 0)
 143         disorder_fatal(errno, "close");
 144       /* We don't want to hang onto whatever stdin was */
 145       if((fd = open("/dev/null", O_RDONLY)) < 0)
 146         disorder_fatal(errno, "opening /dev/null");
 147       if(dup2(fd, 0) < 0)
 148         disorder_fatal(errno, "dup2");
 149       if(close(fd) < 0)
 150         disorder_fatal(errno, "close");
 151       /* execute the player */
 152       execlp("disorder-playrtp",
 153              "disorder-playrtp",
 154              "--socket", rtp_socket,
 155              "--api", rtp_api,
 156              (char *)0);
 157       disorder_fatal(errno, "disorder-playrtp");
 158     } else {
 159       /* child */
 160       _exit(0);
 161     }
 162   } else {
 163     /* parent */
 164     while(waitpid(pid, &w, 0) < 0 && errno == EINTR)
 165       ;
 166   }
 167 }
 168
 169 /** @brief Stop the RTP player if it is running */
 170 void stop_rtp(void) {
 171   FILE *fp = rtp_connect();
 172
 173   if(!fp)
 174     return;                             /* already stopped */
 175   fprintf(fp, "stop\n");
 176   fclose(fp);
 177 }
 178
 179 static char *rtp_config_file(void) {
 180   static char *rtp_config;
 181   const char *home = getenv("HOME");
 182   if(!rtp_config)
 183     byte_xasprintf(&rtp_config, "%s/.disorder/api", home);
 184   return rtp_config;
 185 }
 186
 187 const char *rtp_api;
 188
 189 void load_rtp_config(void) {
 190   char *rtp_config = rtp_config_file();
 191   FILE *fp;
 192   if((fp = fopen(rtp_config, "r"))) {
 193     char *line;
 194     if(inputline(rtp_config, fp, &line, '\n') == 0) {
 195       for(int n = 0; uaudio_apis[n]; ++n)
 196         if(!strcmp(uaudio_apis[n]->name, line))
 197           rtp_api = line;
 198     }
 199     fclose(fp);
 200   }
 201   if(!rtp_api)
 202     rtp_api = uaudio_default(uaudio_apis, UAUDIO_API_CLIENT)->name;
 203 }
 204
 205 void save_rtp_config(void) {
 206   if(rtp_api) {
 207     char *rtp_config = rtp_config_file();
 208     char *tmp;
 209     byte_xasprintf(&tmp, "%s.tmp", rtp_config);
 210     FILE *fp;
 211     if(!(fp = fopen(tmp, "w"))){
 212       fpopup_msg(GTK_MESSAGE_ERROR, "error opening %s: %s",
 213                  tmp, strerror(errno));
 214       return;
 215     }
 216     if(fprintf(fp, "%s\n", rtp_api) < 0) {
 217       fpopup_msg(GTK_MESSAGE_ERROR, "error writing to %s: %s",
 218                  tmp, strerror(errno));
 219       fclose(fp);
 220       return;
 221     }
 222     if(fclose(fp) < 0) {
 223       fpopup_msg(GTK_MESSAGE_ERROR, "error closing %s: %s",
 224                  tmp, strerror(errno));
 225       return;
 226     }
 227     if(rename(tmp, rtp_config) < 0) {
 228       fpopup_msg(GTK_MESSAGE_ERROR, "error renaming %s: %s",
 229                  tmp, strerror(errno));
 230     }
 231   }
 232 }
 233
 234 void change_rtp_api(const char *api) {
 235   if(rtp_api && !strcmp(api, rtp_api))
 236     return;                             /* no change */
 237   int running = rtp_running();
 238   if(running)
 239     stop_rtp();
 240   rtp_api = api;
 241   save_rtp_config();
 242   // TODO this is racy and does not work; the player doesn't shut down quickly
 243   // enough.
 244   if(running)
 245     start_rtp();
 246 }
 247
 248 /*
 249 Local Variables:
 250 c-basic-offset:2
 251 comment-column:40
 252 fill-column:79
 253 indent-tabs-mode:nil
 254 End:
 255 */