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 static char *substitute_instance_name(void) {
  38   const char *p = config->rtp_instance_name;
  39   struct utsname uts;
  40   size_t n;
  41   int ok;
  42   struct dynstr z;
  43
  44   ok = (uname(&uts) >= 0);
  45   if(!p) p = "%h-rtp";
  46   dynstr_init(&z);
  47   for(;;) {
  48     n = strcspn(p, "%");
  49     if(n) { dynstr_append_bytes(&z, p, n); p += n; }
  50     if(!*p) break;
  51     p++;
  52     switch(*p) {
  53     case '%': dynstr_append_bytes(&z, "%", 1); p++; break;
  54     case 'h':
  55       if(ok) { dynstr_append_string(&z, uts.nodename); p++; }
  56       else { p++; if(*p) p++; }
  57     case 0: break;
  58     default: dynstr_append_bytes(&z, p - 1, 2); p++; break;
  59     }
  60   }
  61   dynstr_terminate(&z);
  62   return z.vec;
  63 }
  64
  65 /** @brief Initialize @ref rtp_socket and @ref rtp_log if necessary */
  66 static void rtp_init(void) {
  67   if(!rtp_socket) {
  68     const char *home = getenv("HOME");
  69     char *dir, *instance;
  70
  71     byte_xasprintf(&dir, "%s/.disorder/", home);
  72     mkdir(dir, 02700);
  73     instance = substitute_instance_name();
  74     byte_xasprintf(&rtp_socket, "%s%s", dir, instance);
  75     byte_xasprintf(&rtp_log, "%s%s.log", dir, instance);
  76   }
  77 }
  78
  79 /** @brief Return a connection to the RTP player's control socket */
  80 static FILE *rtp_connect(void) {
  81   struct sockaddr_un un;
  82   int fd;
  83   FILE *fp;
  84
  85   rtp_init();
  86   memset(&un, 0, sizeof un);
  87   un.sun_family = AF_UNIX;
  88   strcpy(un.sun_path, rtp_socket);
  89   fd = xsocket(PF_UNIX, SOCK_STREAM, 0);
  90   if(connect(fd, (const struct sockaddr *)&un, sizeof un) < 0) {
  91     /* Connection refused just means that the player quit without deleting its
  92      * socket */
  93     switch(errno) {
  94     case ECONNREFUSED:
  95     case ENOENT:
  96       break;
  97     default:
  98       /* Anything else may be a problem */
  99       fpopup_msg(GTK_MESSAGE_ERROR, "connecting to %s: %s",
 100                  rtp_socket, strerror(errno));
 101       break;
 102     }
 103     close(fd);
 104     return 0;
 105   }
 106   if(!(fp = fdopen(fd, "r+"))) {
 107     fpopup_msg(GTK_MESSAGE_ERROR, "error calling fdopen: %s", strerror(errno));
 108     close(fd);
 109     return 0;
 110   }
 111   return fp;
 112 }
 113
 114 /** @brief Return non-0 iff the RTP player is running */
 115 int rtp_running(void) {
 116   FILE *fp = rtp_connect();
 117
 118   if(!fp)
 119     return 0;                           /* no connection -> not running */
 120   fclose(fp);                           /* connection -> running */
 121   return 1;
 122 }
 123
 124 int rtp_getvol(int *l, int *r) {
 125   FILE *fp;
 126   int rc = -1;
 127
 128   fp = rtp_connect(); if(!fp) goto end;
 129   fprintf(fp, "getvol\n"); fflush(fp);
 130   if(fscanf(fp, "%d %d\n", l, r) != 2) goto end;
 131   rc = 0;
 132 end:
 133   if(fp) fclose(fp);
 134   return rc;
 135 }
 136
 137 int rtp_setvol(int *l, int *r) {
 138   FILE *fp = rtp_connect(); if(!fp) return -1;
 139   fprintf(fp, "setvol %d %d\n", *l, *r); fflush(fp);
 140   if(fscanf(fp, "%d %d\n", l, r) != 2) { /* do nothing */ }
 141   fclose(fp);
 142   return 0;
 143 }
 144
 145 /** @brief Activate the RTP player if it is not running */
 146 void start_rtp(void) {
 147   pid_t pid;
 148   int w, fd;
 149
 150   if(rtp_running())
 151     return;                             /* already running */
 152   /* double-fork so we don't have to wait() later */
 153   if(!(pid = xfork())) {
 154     if(setsid() < 0)
 155       disorder_fatal(errno, "error calling setsid");
 156     if(!xfork()) {
 157       /* grandchild */
 158       exitfn = _exit;
 159       /* log errors and output somewhere reasonably sane.  rtp_running()
 160        * will have made sure the directory exists. */
 161       if((fd = open(rtp_log, O_WRONLY|O_CREAT|O_TRUNC, 0600)) < 0)
 162         disorder_fatal(errno, "creating %s", rtp_log);
 163       if(dup2(fd, 1) < 0
 164          || dup2(fd, 2) < 0)
 165         disorder_fatal(errno, "dup2");
 166       if(close(fd) < 0)
 167         disorder_fatal(errno, "close");
 168       /* We don't want to hang onto whatever stdin was */
 169       if((fd = open("/dev/null", O_RDONLY)) < 0)
 170         disorder_fatal(errno, "opening /dev/null");
 171       if(dup2(fd, 0) < 0)
 172         disorder_fatal(errno, "dup2");
 173       if(close(fd) < 0)
 174         disorder_fatal(errno, "close");
 175       /* execute the player */
 176       execlp("disorder-playrtp",
 177              "disorder-playrtp",
 178              "--socket", rtp_socket,
 179              "--api", rtp_api,
 180              (char *)0);
 181       disorder_fatal(errno, "disorder-playrtp");
 182     } else {
 183       /* child */
 184       _exit(0);
 185     }
 186   } else {
 187     /* parent */
 188     while(waitpid(pid, &w, 0) < 0 && errno == EINTR)
 189       ;
 190   }
 191 }
 192
 193 /** @brief Stop the RTP player if it is running */
 194 void stop_rtp(void) {
 195   FILE *fp = rtp_connect();
 196
 197   if(!fp)
 198     return;                             /* already stopped */
 199   fprintf(fp, "stop\n");
 200   fclose(fp);
 201 }
 202
 203 static char *rtp_config_file(void) {
 204   static char *rtp_config;
 205   const char *home = getenv("HOME");
 206   if(!rtp_config)
 207     byte_xasprintf(&rtp_config, "%s/.disorder/api", home);
 208   return rtp_config;
 209 }
 210
 211 const char *rtp_api;
 212
 213 void load_rtp_config(void) {
 214   char *rtp_config = rtp_config_file();
 215   FILE *fp;
 216   if((fp = fopen(rtp_config, "r"))) {
 217     char *line;
 218     if(inputline(rtp_config, fp, &line, '\n') == 0) {
 219       for(int n = 0; uaudio_apis[n]; ++n)
 220         if(!strcmp(uaudio_apis[n]->name, line))
 221           rtp_api = line;
 222     }
 223     fclose(fp);
 224   }
 225   if(!rtp_api)
 226     rtp_api = uaudio_default(uaudio_apis, UAUDIO_API_CLIENT)->name;
 227 }
 228
 229 void save_rtp_config(void) {
 230   if(rtp_api) {
 231     char *rtp_config = rtp_config_file();
 232     char *tmp;
 233     byte_xasprintf(&tmp, "%s.tmp", rtp_config);
 234     FILE *fp;
 235     if(!(fp = fopen(tmp, "w"))){
 236       fpopup_msg(GTK_MESSAGE_ERROR, "error opening %s: %s",
 237                  tmp, strerror(errno));
 238       return;
 239     }
 240     if(fprintf(fp, "%s\n", rtp_api) < 0) {
 241       fpopup_msg(GTK_MESSAGE_ERROR, "error writing to %s: %s",
 242                  tmp, strerror(errno));
 243       fclose(fp);
 244       return;
 245     }
 246     if(fclose(fp) < 0) {
 247       fpopup_msg(GTK_MESSAGE_ERROR, "error closing %s: %s",
 248                  tmp, strerror(errno));
 249       return;
 250     }
 251     if(rename(tmp, rtp_config) < 0) {
 252       fpopup_msg(GTK_MESSAGE_ERROR, "error renaming %s: %s",
 253                  tmp, strerror(errno));
 254     }
 255   }
 256 }
 257
 258 void change_rtp_api(const char *api) {
 259   if(rtp_api && !strcmp(api, rtp_api))
 260     return;                             /* no change */
 261   int running = rtp_running();
 262   if(running)
 263     stop_rtp();
 264   rtp_api = api;
 265   save_rtp_config();
 266   // TODO this is racy and does not work; the player doesn't shut down quickly
 267   // enough.
 268   if(running)
 269     start_rtp();
 270 }
 271
 272 /*
 273 Local Variables:
 274 c-basic-offset:2
 275 comment-column:40
 276 fill-column:79
 277 indent-tabs-mode:nil
 278 End:
 279 */