Home | History | Annotate | Download | only in linux
      1 /*
      2     SDL - Simple DirectMedia Layer
      3     Copyright (C) 1997-2012 Sam Lantinga
      4 
      5     This library is free software; you can redistribute it and/or
      6     modify it under the terms of the GNU Lesser General Public
      7     License as published by the Free Software Foundation; either
      8     version 2.1 of the License, or (at your option) any later version.
      9 
     10     This library 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 GNU
     13     Lesser General Public License for more details.
     14 
     15     You should have received a copy of the GNU Lesser General Public
     16     License along with this library; if not, write to the Free Software
     17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     18 
     19     Sam Lantinga
     20     slouken (at) libsdl.org
     21 */
     22 #include "SDL_config.h"
     23 
     24 #ifdef SDL_CDROM_LINUX
     25 
     26 /* Functions for system-level CD-ROM audio control */
     27 
     28 #include <string.h>	/* For strerror() */
     29 #include <sys/types.h>
     30 #include <sys/stat.h>
     31 #include <sys/ioctl.h>
     32 #include <fcntl.h>
     33 #include <errno.h>
     34 #include <unistd.h>
     35 #ifdef __LINUX__
     36 #ifdef HAVE_LINUX_VERSION_H
     37 /* linux 2.6.9 workaround */
     38 #include <linux/version.h>
     39 #if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,9)
     40 #include <asm/types.h>
     41 #define __le64 __u64
     42 #define __le32 __u32
     43 #define __le16 __u16
     44 #define __be64 __u64
     45 #define __be32 __u32
     46 #define __be16 __u16
     47 #endif /* linux 2.6.9 workaround */
     48 #endif /* HAVE_LINUX_VERSION_H */
     49 #include <linux/cdrom.h>
     50 #endif
     51 #ifdef __SVR4
     52 #include <sys/cdio.h>
     53 #endif
     54 
     55 /* Define this to use the alternative getmntent() code */
     56 #ifndef __SVR4
     57 #define USE_MNTENT
     58 #endif
     59 
     60 #ifdef USE_MNTENT
     61 #if defined(__USLC__)
     62 #include <sys/mntent.h>
     63 #else
     64 #include <mntent.h>
     65 #endif
     66 
     67 #ifndef _PATH_MNTTAB
     68 #ifdef MNTTAB
     69 #define _PATH_MNTTAB	MNTTAB
     70 #else
     71 #define _PATH_MNTTAB	"/etc/fstab"
     72 #endif
     73 #endif /* !_PATH_MNTTAB */
     74 
     75 #ifndef _PATH_MOUNTED
     76 #define _PATH_MOUNTED	"/etc/mtab"
     77 #endif /* !_PATH_MOUNTED */
     78 
     79 #ifndef MNTTYPE_CDROM
     80 #define MNTTYPE_CDROM	"iso9660"
     81 #endif
     82 #ifndef MNTTYPE_SUPER
     83 #define MNTTYPE_SUPER	"supermount"
     84 #endif
     85 #endif /* USE_MNTENT */
     86 
     87 #include "SDL_cdrom.h"
     88 #include "../SDL_syscdrom.h"
     89 
     90 
     91 /* The maximum number of CD-ROM drives we'll detect */
     92 #define MAX_DRIVES	16
     93 
     94 /* A list of available CD-ROM drives */
     95 static char *SDL_cdlist[MAX_DRIVES];
     96 static dev_t SDL_cdmode[MAX_DRIVES];
     97 
     98 /* The system-dependent CD control functions */
     99 static const char *SDL_SYS_CDName(int drive);
    100 static int SDL_SYS_CDOpen(int drive);
    101 static int SDL_SYS_CDGetTOC(SDL_CD *cdrom);
    102 static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position);
    103 static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length);
    104 static int SDL_SYS_CDPause(SDL_CD *cdrom);
    105 static int SDL_SYS_CDResume(SDL_CD *cdrom);
    106 static int SDL_SYS_CDStop(SDL_CD *cdrom);
    107 static int SDL_SYS_CDEject(SDL_CD *cdrom);
    108 static void SDL_SYS_CDClose(SDL_CD *cdrom);
    109 
    110 /* Some ioctl() errno values which occur when the tray is empty */
    111 #ifndef ENOMEDIUM
    112 #define ENOMEDIUM ENOENT
    113 #endif
    114 #define ERRNO_TRAYEMPTY(errno)	\
    115 	((errno == EIO)    || (errno == ENOENT) || \
    116 	 (errno == EINVAL) || (errno == ENOMEDIUM))
    117 
    118 /* Check a drive to see if it is a CD-ROM */
    119 static int CheckDrive(char *drive, char *mnttype, struct stat *stbuf)
    120 {
    121 	int is_cd, cdfd;
    122 	struct cdrom_subchnl info;
    123 
    124 	/* If it doesn't exist, return -1 */
    125 	if ( stat(drive, stbuf) < 0 ) {
    126 		return(-1);
    127 	}
    128 
    129 	/* If it does exist, verify that it's an available CD-ROM */
    130 	is_cd = 0;
    131 	if ( S_ISCHR(stbuf->st_mode) || S_ISBLK(stbuf->st_mode) ) {
    132 		cdfd = open(drive, (O_RDONLY|O_NONBLOCK), 0);
    133 		if ( cdfd >= 0 ) {
    134 			info.cdsc_format = CDROM_MSF;
    135 			/* Under Linux, EIO occurs when a disk is not present.
    136 			 */
    137 			if ( (ioctl(cdfd, CDROMSUBCHNL, &info) == 0) ||
    138 						ERRNO_TRAYEMPTY(errno) ) {
    139 				is_cd = 1;
    140 			}
    141 			close(cdfd);
    142 		}
    143 #ifdef USE_MNTENT
    144 		/* Even if we can't read it, it might be mounted */
    145 		else if ( mnttype && (SDL_strcmp(mnttype, MNTTYPE_CDROM) == 0) ) {
    146 			is_cd = 1;
    147 		}
    148 #endif
    149 	}
    150 	return(is_cd);
    151 }
    152 
    153 /* Add a CD-ROM drive to our list of valid drives */
    154 static void AddDrive(char *drive, struct stat *stbuf)
    155 {
    156 	int i;
    157 
    158 	if ( SDL_numcds < MAX_DRIVES ) {
    159 		/* Check to make sure it's not already in our list.
    160 	 	   This can happen when we see a drive via symbolic link.
    161 		 */
    162 		for ( i=0; i<SDL_numcds; ++i ) {
    163 			if ( stbuf->st_rdev == SDL_cdmode[i] ) {
    164 #ifdef DEBUG_CDROM
    165   fprintf(stderr, "Duplicate drive detected: %s == %s\n", drive, SDL_cdlist[i]);
    166 #endif
    167 				return;
    168 			}
    169 		}
    170 
    171 		/* Add this drive to our list */
    172 		i = SDL_numcds;
    173 		SDL_cdlist[i] = SDL_strdup(drive);
    174 		if ( SDL_cdlist[i] == NULL ) {
    175 			SDL_OutOfMemory();
    176 			return;
    177 		}
    178 		SDL_cdmode[i] = stbuf->st_rdev;
    179 		++SDL_numcds;
    180 #ifdef DEBUG_CDROM
    181   fprintf(stderr, "Added CD-ROM drive: %s\n", drive);
    182 #endif
    183 	}
    184 }
    185 
    186 #ifdef USE_MNTENT
    187 static void CheckMounts(const char *mtab)
    188 {
    189 	FILE *mntfp;
    190 	struct mntent *mntent;
    191 	struct stat stbuf;
    192 
    193 	mntfp = setmntent(mtab, "r");
    194 	if ( mntfp != NULL ) {
    195 		char *tmp;
    196 		char *mnt_type;
    197 		size_t mnt_type_len;
    198 		char *mnt_dev;
    199 		size_t mnt_dev_len;
    200 
    201 		while ( (mntent=getmntent(mntfp)) != NULL ) {
    202 			mnt_type_len = SDL_strlen(mntent->mnt_type) + 1;
    203 			mnt_type = SDL_stack_alloc(char, mnt_type_len);
    204 			if (mnt_type == NULL)
    205 				continue;  /* maybe you'll get lucky next time. */
    206 
    207 			mnt_dev_len = SDL_strlen(mntent->mnt_fsname) + 1;
    208 			mnt_dev = SDL_stack_alloc(char, mnt_dev_len);
    209 			if (mnt_dev == NULL) {
    210 				SDL_stack_free(mnt_type);
    211 				continue;
    212 			}
    213 
    214 			SDL_strlcpy(mnt_type, mntent->mnt_type, mnt_type_len);
    215 			SDL_strlcpy(mnt_dev, mntent->mnt_fsname, mnt_dev_len);
    216 
    217 			/* Handle "supermount" filesystem mounts */
    218 			if ( SDL_strcmp(mnt_type, MNTTYPE_SUPER) == 0 ) {
    219 				tmp = SDL_strstr(mntent->mnt_opts, "fs=");
    220 				if ( tmp ) {
    221 					SDL_stack_free(mnt_type);
    222 					mnt_type = SDL_strdup(tmp + SDL_strlen("fs="));
    223 					if ( mnt_type ) {
    224 						tmp = SDL_strchr(mnt_type, ',');
    225 						if ( tmp ) {
    226 							*tmp = '\0';
    227 						}
    228 					}
    229 				}
    230 				tmp = SDL_strstr(mntent->mnt_opts, "dev=");
    231 				if ( tmp ) {
    232 					SDL_stack_free(mnt_dev);
    233 					mnt_dev = SDL_strdup(tmp + SDL_strlen("dev="));
    234 					if ( mnt_dev ) {
    235 						tmp = SDL_strchr(mnt_dev, ',');
    236 						if ( tmp ) {
    237 							*tmp = '\0';
    238 						}
    239 					}
    240 				}
    241 			}
    242 			if ( SDL_strcmp(mnt_type, MNTTYPE_CDROM) == 0 ) {
    243 #ifdef DEBUG_CDROM
    244   fprintf(stderr, "Checking mount path from %s: %s mounted on %s of %s\n",
    245 	mtab, mnt_dev, mntent->mnt_dir, mnt_type);
    246 #endif
    247 				if (CheckDrive(mnt_dev, mnt_type, &stbuf) > 0) {
    248 					AddDrive(mnt_dev, &stbuf);
    249 				}
    250 			}
    251 			SDL_stack_free(mnt_dev);
    252 			SDL_stack_free(mnt_type);
    253 		}
    254 		endmntent(mntfp);
    255 	}
    256 }
    257 #endif /* USE_MNTENT */
    258 
    259 int  SDL_SYS_CDInit(void)
    260 {
    261 	/* checklist: /dev/cdrom, /dev/hd?, /dev/scd? /dev/sr? */
    262 	static char *checklist[] = {
    263 		"cdrom", "?a hd?", "?0 scd?", "?0 sr?", NULL
    264 	};
    265 	char *SDLcdrom;
    266 	int i, j, exists;
    267 	char drive[32];
    268 	struct stat stbuf;
    269 
    270 	/* Fill in our driver capabilities */
    271 	SDL_CDcaps.Name = SDL_SYS_CDName;
    272 	SDL_CDcaps.Open = SDL_SYS_CDOpen;
    273 	SDL_CDcaps.GetTOC = SDL_SYS_CDGetTOC;
    274 	SDL_CDcaps.Status = SDL_SYS_CDStatus;
    275 	SDL_CDcaps.Play = SDL_SYS_CDPlay;
    276 	SDL_CDcaps.Pause = SDL_SYS_CDPause;
    277 	SDL_CDcaps.Resume = SDL_SYS_CDResume;
    278 	SDL_CDcaps.Stop = SDL_SYS_CDStop;
    279 	SDL_CDcaps.Eject = SDL_SYS_CDEject;
    280 	SDL_CDcaps.Close = SDL_SYS_CDClose;
    281 
    282 	/* Look in the environment for our CD-ROM drive list */
    283 	SDLcdrom = SDL_getenv("SDL_CDROM");	/* ':' separated list of devices */
    284 	if ( SDLcdrom != NULL ) {
    285 		char *cdpath, *delim;
    286 		size_t len = SDL_strlen(SDLcdrom)+1;
    287 		cdpath = SDL_stack_alloc(char, len);
    288 		if ( cdpath != NULL ) {
    289 			SDL_strlcpy(cdpath, SDLcdrom, len);
    290 			SDLcdrom = cdpath;
    291 			do {
    292 				delim = SDL_strchr(SDLcdrom, ':');
    293 				if ( delim ) {
    294 					*delim++ = '\0';
    295 				}
    296 #ifdef DEBUG_CDROM
    297   fprintf(stderr, "Checking CD-ROM drive from SDL_CDROM: %s\n", SDLcdrom);
    298 #endif
    299 				if ( CheckDrive(SDLcdrom, NULL, &stbuf) > 0 ) {
    300 					AddDrive(SDLcdrom, &stbuf);
    301 				}
    302 				if ( delim ) {
    303 					SDLcdrom = delim;
    304 				} else {
    305 					SDLcdrom = NULL;
    306 				}
    307 			} while ( SDLcdrom );
    308 			SDL_stack_free(cdpath);
    309 		}
    310 
    311 		/* If we found our drives, there's nothing left to do */
    312 		if ( SDL_numcds > 0 ) {
    313 			return(0);
    314 		}
    315 	}
    316 
    317 #ifdef USE_MNTENT
    318 	/* Check /dev/cdrom first :-) */
    319 	if (CheckDrive("/dev/cdrom", NULL, &stbuf) > 0) {
    320 		AddDrive("/dev/cdrom", &stbuf);
    321 	}
    322 
    323 	/* Now check the currently mounted CD drives */
    324 	CheckMounts(_PATH_MOUNTED);
    325 
    326 	/* Finally check possible mountable drives in /etc/fstab */
    327 	CheckMounts(_PATH_MNTTAB);
    328 
    329 	/* If we found our drives, there's nothing left to do */
    330 	if ( SDL_numcds > 0 ) {
    331 		return(0);
    332 	}
    333 #endif /* USE_MNTENT */
    334 
    335 	/* Scan the system for CD-ROM drives.
    336 	   Not always 100% reliable, so use the USE_MNTENT code above first.
    337 	 */
    338 	for ( i=0; checklist[i]; ++i ) {
    339 		if ( checklist[i][0] == '?' ) {
    340 			char *insert;
    341 			exists = 1;
    342 			for ( j=checklist[i][1]; exists; ++j ) {
    343 				SDL_snprintf(drive, SDL_arraysize(drive), "/dev/%s", &checklist[i][3]);
    344 				insert = SDL_strchr(drive, '?');
    345 				if ( insert != NULL ) {
    346 					*insert = j;
    347 				}
    348 #ifdef DEBUG_CDROM
    349   fprintf(stderr, "Checking possible CD-ROM drive: %s\n", drive);
    350 #endif
    351 				switch (CheckDrive(drive, NULL, &stbuf)) {
    352 					/* Drive exists and is a CD-ROM */
    353 					case 1:
    354 						AddDrive(drive, &stbuf);
    355 						break;
    356 					/* Drive exists, but isn't a CD-ROM */
    357 					case 0:
    358 						break;
    359 					/* Drive doesn't exist */
    360 					case -1:
    361 						exists = 0;
    362 						break;
    363 				}
    364 			}
    365 		} else {
    366 			SDL_snprintf(drive, SDL_arraysize(drive), "/dev/%s", checklist[i]);
    367 #ifdef DEBUG_CDROM
    368   fprintf(stderr, "Checking possible CD-ROM drive: %s\n", drive);
    369 #endif
    370 			if ( CheckDrive(drive, NULL, &stbuf) > 0 ) {
    371 				AddDrive(drive, &stbuf);
    372 			}
    373 		}
    374 	}
    375 	return(0);
    376 }
    377 
    378 /* General ioctl() CD-ROM command function */
    379 static int SDL_SYS_CDioctl(int id, int command, void *arg)
    380 {
    381 	int retval;
    382 
    383 	retval = ioctl(id, command, arg);
    384 	if ( retval < 0 ) {
    385 		SDL_SetError("ioctl() error: %s", strerror(errno));
    386 	}
    387 	return(retval);
    388 }
    389 
    390 static const char *SDL_SYS_CDName(int drive)
    391 {
    392 	return(SDL_cdlist[drive]);
    393 }
    394 
    395 static int SDL_SYS_CDOpen(int drive)
    396 {
    397 	return(open(SDL_cdlist[drive], (O_RDONLY|O_NONBLOCK), 0));
    398 }
    399 
    400 static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)
    401 {
    402 	struct cdrom_tochdr toc;
    403 	int i, okay;
    404 	struct cdrom_tocentry entry;
    405 
    406 	okay = 0;
    407 	if ( SDL_SYS_CDioctl(cdrom->id, CDROMREADTOCHDR, &toc) == 0 ) {
    408 		cdrom->numtracks = toc.cdth_trk1-toc.cdth_trk0+1;
    409 		if ( cdrom->numtracks > SDL_MAX_TRACKS ) {
    410 			cdrom->numtracks = SDL_MAX_TRACKS;
    411 		}
    412 		/* Read all the track TOC entries */
    413 		for ( i=0; i<=cdrom->numtracks; ++i ) {
    414 			if ( i == cdrom->numtracks ) {
    415 				cdrom->track[i].id = CDROM_LEADOUT;
    416 			} else {
    417 				cdrom->track[i].id = toc.cdth_trk0+i;
    418 			}
    419 			entry.cdte_track = cdrom->track[i].id;
    420 			entry.cdte_format = CDROM_MSF;
    421 			if ( SDL_SYS_CDioctl(cdrom->id, CDROMREADTOCENTRY,
    422 								&entry) < 0 ) {
    423 				break;
    424 			} else {
    425 				if ( entry.cdte_ctrl & CDROM_DATA_TRACK ) {
    426 					cdrom->track[i].type = SDL_DATA_TRACK;
    427 				} else {
    428 					cdrom->track[i].type = SDL_AUDIO_TRACK;
    429 				}
    430 				cdrom->track[i].offset = MSF_TO_FRAMES(
    431 						entry.cdte_addr.msf.minute,
    432 						entry.cdte_addr.msf.second,
    433 						entry.cdte_addr.msf.frame);
    434 				cdrom->track[i].length = 0;
    435 				if ( i > 0 ) {
    436 					cdrom->track[i-1].length =
    437 						cdrom->track[i].offset-
    438 						cdrom->track[i-1].offset;
    439 				}
    440 			}
    441 		}
    442 		if ( i == (cdrom->numtracks+1) ) {
    443 			okay = 1;
    444 		}
    445 	}
    446 	return(okay ? 0 : -1);
    447 }
    448 
    449 /* Get CD-ROM status */
    450 static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position)
    451 {
    452 	CDstatus status;
    453 	struct cdrom_tochdr toc;
    454 	struct cdrom_subchnl info;
    455 
    456 	info.cdsc_format = CDROM_MSF;
    457 	if ( ioctl(cdrom->id, CDROMSUBCHNL, &info) < 0 ) {
    458 		if ( ERRNO_TRAYEMPTY(errno) ) {
    459 			status = CD_TRAYEMPTY;
    460 		} else {
    461 			status = CD_ERROR;
    462 		}
    463 	} else {
    464 		switch (info.cdsc_audiostatus) {
    465 			case CDROM_AUDIO_INVALID:
    466 			case CDROM_AUDIO_NO_STATUS:
    467 				/* Try to determine if there's a CD available */
    468 				if (ioctl(cdrom->id, CDROMREADTOCHDR, &toc)==0)
    469 					status = CD_STOPPED;
    470 				else
    471 					status = CD_TRAYEMPTY;
    472 				break;
    473 			case CDROM_AUDIO_COMPLETED:
    474 				status = CD_STOPPED;
    475 				break;
    476 			case CDROM_AUDIO_PLAY:
    477 				status = CD_PLAYING;
    478 				break;
    479 			case CDROM_AUDIO_PAUSED:
    480 				/* Workaround buggy CD-ROM drive */
    481 				if ( info.cdsc_trk == CDROM_LEADOUT ) {
    482 					status = CD_STOPPED;
    483 				} else {
    484 					status = CD_PAUSED;
    485 				}
    486 				break;
    487 			default:
    488 				status = CD_ERROR;
    489 				break;
    490 		}
    491 	}
    492 	if ( position ) {
    493 		if ( status == CD_PLAYING || (status == CD_PAUSED) ) {
    494 			*position = MSF_TO_FRAMES(
    495 					info.cdsc_absaddr.msf.minute,
    496 					info.cdsc_absaddr.msf.second,
    497 					info.cdsc_absaddr.msf.frame);
    498 		} else {
    499 			*position = 0;
    500 		}
    501 	}
    502 	return(status);
    503 }
    504 
    505 /* Start play */
    506 static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length)
    507 {
    508 	struct cdrom_msf playtime;
    509 
    510 	FRAMES_TO_MSF(start,
    511 	   &playtime.cdmsf_min0, &playtime.cdmsf_sec0, &playtime.cdmsf_frame0);
    512 	FRAMES_TO_MSF(start+length,
    513 	   &playtime.cdmsf_min1, &playtime.cdmsf_sec1, &playtime.cdmsf_frame1);
    514 #ifdef DEBUG_CDROM
    515   fprintf(stderr, "Trying to play from %d:%d:%d to %d:%d:%d\n",
    516 	playtime.cdmsf_min0, playtime.cdmsf_sec0, playtime.cdmsf_frame0,
    517 	playtime.cdmsf_min1, playtime.cdmsf_sec1, playtime.cdmsf_frame1);
    518 #endif
    519 	return(SDL_SYS_CDioctl(cdrom->id, CDROMPLAYMSF, &playtime));
    520 }
    521 
    522 /* Pause play */
    523 static int SDL_SYS_CDPause(SDL_CD *cdrom)
    524 {
    525 	return(SDL_SYS_CDioctl(cdrom->id, CDROMPAUSE, 0));
    526 }
    527 
    528 /* Resume play */
    529 static int SDL_SYS_CDResume(SDL_CD *cdrom)
    530 {
    531 	return(SDL_SYS_CDioctl(cdrom->id, CDROMRESUME, 0));
    532 }
    533 
    534 /* Stop play */
    535 static int SDL_SYS_CDStop(SDL_CD *cdrom)
    536 {
    537 	return(SDL_SYS_CDioctl(cdrom->id, CDROMSTOP, 0));
    538 }
    539 
    540 /* Eject the CD-ROM */
    541 static int SDL_SYS_CDEject(SDL_CD *cdrom)
    542 {
    543 	return(SDL_SYS_CDioctl(cdrom->id, CDROMEJECT, 0));
    544 }
    545 
    546 /* Close the CD-ROM handle */
    547 static void SDL_SYS_CDClose(SDL_CD *cdrom)
    548 {
    549 	close(cdrom->id);
    550 }
    551 
    552 void SDL_SYS_CDQuit(void)
    553 {
    554 	int i;
    555 
    556 	if ( SDL_numcds > 0 ) {
    557 		for ( i=0; i<SDL_numcds; ++i ) {
    558 			SDL_free(SDL_cdlist[i]);
    559 		}
    560 		SDL_numcds = 0;
    561 	}
    562 }
    563 
    564 #endif /* SDL_CDROM_LINUX */
    565