chiark / gitweb /
import udev repository
[elogind.git] / src / udev / src / cdrom_id / cdrom_id.c
diff --git a/src/udev/src/cdrom_id/cdrom_id.c b/src/udev/src/cdrom_id/cdrom_id.c
new file mode 100644 (file)
index 0000000..f90d52e
--- /dev/null
@@ -0,0 +1,1099 @@
+/*
+ * cdrom_id - optical drive and media information prober
+ *
+ * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <getopt.h>
+#include <time.h>
+#include <scsi/sg.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <linux/cdrom.h>
+
+#include "libudev.h"
+#include "libudev-private.h"
+
+static bool debug;
+
+static void log_fn(struct udev *udev, int priority,
+                   const char *file, int line, const char *fn,
+                   const char *format, va_list args)
+{
+        if (debug) {
+                fprintf(stderr, "%s: ", fn);
+                vfprintf(stderr, format, args);
+        } else {
+                vsyslog(priority, format, args);
+        }
+}
+
+/* device info */
+static unsigned int cd_cd_rom;
+static unsigned int cd_cd_r;
+static unsigned int cd_cd_rw;
+static unsigned int cd_dvd_rom;
+static unsigned int cd_dvd_r;
+static unsigned int cd_dvd_rw;
+static unsigned int cd_dvd_ram;
+static unsigned int cd_dvd_plus_r;
+static unsigned int cd_dvd_plus_rw;
+static unsigned int cd_dvd_plus_r_dl;
+static unsigned int cd_dvd_plus_rw_dl;
+static unsigned int cd_bd;
+static unsigned int cd_bd_r;
+static unsigned int cd_bd_re;
+static unsigned int cd_hddvd;
+static unsigned int cd_hddvd_r;
+static unsigned int cd_hddvd_rw;
+static unsigned int cd_mo;
+static unsigned int cd_mrw;
+static unsigned int cd_mrw_w;
+
+/* media info */
+static unsigned int cd_media;
+static unsigned int cd_media_cd_rom;
+static unsigned int cd_media_cd_r;
+static unsigned int cd_media_cd_rw;
+static unsigned int cd_media_dvd_rom;
+static unsigned int cd_media_dvd_r;
+static unsigned int cd_media_dvd_rw;
+static unsigned int cd_media_dvd_rw_ro; /* restricted overwrite mode */
+static unsigned int cd_media_dvd_rw_seq; /* sequential mode */
+static unsigned int cd_media_dvd_ram;
+static unsigned int cd_media_dvd_plus_r;
+static unsigned int cd_media_dvd_plus_rw;
+static unsigned int cd_media_dvd_plus_r_dl;
+static unsigned int cd_media_dvd_plus_rw_dl;
+static unsigned int cd_media_bd;
+static unsigned int cd_media_bd_r;
+static unsigned int cd_media_bd_re;
+static unsigned int cd_media_hddvd;
+static unsigned int cd_media_hddvd_r;
+static unsigned int cd_media_hddvd_rw;
+static unsigned int cd_media_mo;
+static unsigned int cd_media_mrw;
+static unsigned int cd_media_mrw_w;
+
+static const char *cd_media_state = NULL;
+static unsigned int cd_media_session_next;
+static unsigned int cd_media_session_count;
+static unsigned int cd_media_track_count;
+static unsigned int cd_media_track_count_data;
+static unsigned int cd_media_track_count_audio;
+static unsigned long long int cd_media_session_last_offset;
+
+#define ERRCODE(s)        ((((s)[2] & 0x0F) << 16) | ((s)[12] << 8) | ((s)[13]))
+#define SK(errcode)        (((errcode) >> 16) & 0xF)
+#define ASC(errcode)        (((errcode) >> 8) & 0xFF)
+#define ASCQ(errcode)        ((errcode) & 0xFF)
+
+static bool is_mounted(const char *device)
+{
+        struct stat statbuf;
+        FILE *fp;
+        int maj, min;
+        bool mounted = false;
+
+        if (stat(device, &statbuf) < 0)
+                return -ENODEV;
+
+        fp = fopen("/proc/self/mountinfo", "r");
+        if (fp == NULL)
+                return -ENOSYS;
+        while (fscanf(fp, "%*s %*s %i:%i %*[^\n]", &maj, &min) == 2) {
+                if (makedev(maj, min) == statbuf.st_rdev) {
+                        mounted = true;
+                        break;
+                }
+        }
+        fclose(fp);
+        return mounted;
+}
+
+static void info_scsi_cmd_err(struct udev *udev, char *cmd, int err)
+{
+        if (err == -1) {
+                info(udev, "%s failed\n", cmd);
+                return;
+        }
+        info(udev, "%s failed with SK=%Xh/ASC=%02Xh/ACQ=%02Xh\n", cmd, SK(err), ASC(err), ASCQ(err));
+}
+
+struct scsi_cmd {
+        struct cdrom_generic_command cgc;
+        union {
+                struct request_sense s;
+                unsigned char u[18];
+        } _sense;
+        struct sg_io_hdr sg_io;
+};
+
+static void scsi_cmd_init(struct udev *udev, struct scsi_cmd *cmd)
+{
+        memset(cmd, 0x00, sizeof(struct scsi_cmd));
+        cmd->cgc.quiet = 1;
+        cmd->cgc.sense = &cmd->_sense.s;
+        cmd->sg_io.interface_id = 'S';
+        cmd->sg_io.mx_sb_len = sizeof(cmd->_sense);
+        cmd->sg_io.cmdp = cmd->cgc.cmd;
+        cmd->sg_io.sbp = cmd->_sense.u;
+        cmd->sg_io.flags = SG_FLAG_LUN_INHIBIT | SG_FLAG_DIRECT_IO;
+}
+
+static void scsi_cmd_set(struct udev *udev, struct scsi_cmd *cmd, size_t i, unsigned char arg)
+{
+        cmd->sg_io.cmd_len = i + 1;
+        cmd->cgc.cmd[i] = arg;
+}
+
+#define CHECK_CONDITION 0x01
+
+static int scsi_cmd_run(struct udev *udev, struct scsi_cmd *cmd, int fd, unsigned char *buf, size_t bufsize)
+{
+        int ret = 0;
+
+        if (bufsize > 0) {
+                cmd->sg_io.dxferp = buf;
+                cmd->sg_io.dxfer_len = bufsize;
+                cmd->sg_io.dxfer_direction = SG_DXFER_FROM_DEV;
+        } else {
+                cmd->sg_io.dxfer_direction = SG_DXFER_NONE;
+        }
+        if (ioctl(fd, SG_IO, &cmd->sg_io))
+                return -1;
+
+        if ((cmd->sg_io.info & SG_INFO_OK_MASK) != SG_INFO_OK) {
+                errno = EIO;
+                ret = -1;
+                if (cmd->sg_io.masked_status & CHECK_CONDITION) {
+                        ret = ERRCODE(cmd->_sense.u);
+                        if (ret == 0)
+                                ret = -1;
+                }
+        }
+        return ret;
+}
+
+static int media_lock(struct udev *udev, int fd, bool lock)
+{
+        int err;
+
+        /* disable the kernel's lock logic */
+        err = ioctl(fd, CDROM_CLEAR_OPTIONS, CDO_LOCK);
+        if (err < 0)
+                info(udev, "CDROM_CLEAR_OPTIONS, CDO_LOCK failed\n");
+
+        err = ioctl(fd, CDROM_LOCKDOOR, lock ? 1 : 0);
+        if (err < 0)
+                info(udev, "CDROM_LOCKDOOR failed\n");
+
+        return err;
+}
+
+static int media_eject(struct udev *udev, int fd)
+{
+        struct scsi_cmd sc;
+        int err;
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x1b);
+        scsi_cmd_set(udev, &sc, 4, 0x02);
+        scsi_cmd_set(udev, &sc, 5, 0);
+        err = scsi_cmd_run(udev, &sc, fd, NULL, 0);
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "START_STOP_UNIT", err);
+                return -1;
+        }
+        return 0;
+}
+
+static int cd_capability_compat(struct udev *udev, int fd)
+{
+        int capability;
+
+        capability = ioctl(fd, CDROM_GET_CAPABILITY, NULL);
+        if (capability < 0) {
+                info(udev, "CDROM_GET_CAPABILITY failed\n");
+                return -1;
+        }
+
+        if (capability & CDC_CD_R)
+                cd_cd_r = 1;
+        if (capability & CDC_CD_RW)
+                cd_cd_rw = 1;
+        if (capability & CDC_DVD)
+                cd_dvd_rom = 1;
+        if (capability & CDC_DVD_R)
+                cd_dvd_r = 1;
+        if (capability & CDC_DVD_RAM)
+                cd_dvd_ram = 1;
+        if (capability & CDC_MRW)
+                cd_mrw = 1;
+        if (capability & CDC_MRW_W)
+                cd_mrw_w = 1;
+        return 0;
+}
+
+static int cd_media_compat(struct udev *udev, int fd)
+{
+        if (ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT) != CDS_DISC_OK) {
+                info(udev, "CDROM_DRIVE_STATUS != CDS_DISC_OK\n");
+                return -1;
+        }
+        cd_media = 1;
+        return 0;
+}
+
+static int cd_inquiry(struct udev *udev, int fd)
+{
+        struct scsi_cmd sc;
+        unsigned char inq[128];
+        int err;
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x12);
+        scsi_cmd_set(udev, &sc, 4, 36);
+        scsi_cmd_set(udev, &sc, 5, 0);
+        err = scsi_cmd_run(udev, &sc, fd, inq, 36);
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "INQUIRY", err);
+                return -1;
+        }
+
+        if ((inq[0] & 0x1F) != 5) {
+                info(udev, "not an MMC unit\n");
+                return -1;
+        }
+
+        info(udev, "INQUIRY: [%.8s][%.16s][%.4s]\n", inq + 8, inq + 16, inq + 32);
+        return 0;
+}
+
+static void feature_profile_media(struct udev *udev, int cur_profile)
+{
+        switch (cur_profile) {
+        case 0x03:
+        case 0x04:
+        case 0x05:
+                info(udev, "profile 0x%02x \n", cur_profile);
+                cd_media = 1;
+                cd_media_mo = 1;
+                break;
+        case 0x08:
+                info(udev, "profile 0x%02x media_cd_rom\n", cur_profile);
+                cd_media = 1;
+                cd_media_cd_rom = 1;
+                break;
+        case 0x09:
+                info(udev, "profile 0x%02x media_cd_r\n", cur_profile);
+                cd_media = 1;
+                cd_media_cd_r = 1;
+                break;
+        case 0x0a:
+                info(udev, "profile 0x%02x media_cd_rw\n", cur_profile);
+                cd_media = 1;
+                cd_media_cd_rw = 1;
+                break;
+        case 0x10:
+                info(udev, "profile 0x%02x media_dvd_ro\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_rom = 1;
+                break;
+        case 0x11:
+                info(udev, "profile 0x%02x media_dvd_r\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_r = 1;
+                break;
+        case 0x12:
+                info(udev, "profile 0x%02x media_dvd_ram\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_ram = 1;
+                break;
+        case 0x13:
+                info(udev, "profile 0x%02x media_dvd_rw_ro\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_rw = 1;
+                cd_media_dvd_rw_ro = 1;
+                break;
+        case 0x14:
+                info(udev, "profile 0x%02x media_dvd_rw_seq\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_rw = 1;
+                cd_media_dvd_rw_seq = 1;
+                break;
+        case 0x1B:
+                info(udev, "profile 0x%02x media_dvd_plus_r\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_plus_r = 1;
+                break;
+        case 0x1A:
+                info(udev, "profile 0x%02x media_dvd_plus_rw\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_plus_rw = 1;
+                break;
+        case 0x2A:
+                info(udev, "profile 0x%02x media_dvd_plus_rw_dl\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_plus_rw_dl = 1;
+                break;
+        case 0x2B:
+                info(udev, "profile 0x%02x media_dvd_plus_r_dl\n", cur_profile);
+                cd_media = 1;
+                cd_media_dvd_plus_r_dl = 1;
+                break;
+        case 0x40:
+                info(udev, "profile 0x%02x media_bd\n", cur_profile);
+                cd_media = 1;
+                cd_media_bd = 1;
+                break;
+        case 0x41:
+        case 0x42:
+                info(udev, "profile 0x%02x media_bd_r\n", cur_profile);
+                cd_media = 1;
+                cd_media_bd_r = 1;
+                break;
+        case 0x43:
+                info(udev, "profile 0x%02x media_bd_re\n", cur_profile);
+                cd_media = 1;
+                cd_media_bd_re = 1;
+                break;
+        case 0x50:
+                info(udev, "profile 0x%02x media_hddvd\n", cur_profile);
+                cd_media = 1;
+                cd_media_hddvd = 1;
+                break;
+        case 0x51:
+                info(udev, "profile 0x%02x media_hddvd_r\n", cur_profile);
+                cd_media = 1;
+                cd_media_hddvd_r = 1;
+                break;
+        case 0x52:
+                info(udev, "profile 0x%02x media_hddvd_rw\n", cur_profile);
+                cd_media = 1;
+                cd_media_hddvd_rw = 1;
+                break;
+        default:
+                info(udev, "profile 0x%02x <ignored>\n", cur_profile);
+                break;
+        }
+}
+
+static int feature_profiles(struct udev *udev, const unsigned char *profiles, size_t size)
+{
+        unsigned int i;
+
+        for (i = 0; i+4 <= size; i += 4) {
+                int profile;
+
+                profile = profiles[i] << 8 | profiles[i+1];
+                switch (profile) {
+                case 0x03:
+                case 0x04:
+                case 0x05:
+                        info(udev, "profile 0x%02x mo\n", profile);
+                        cd_mo = 1;
+                        break;
+                case 0x08:
+                        info(udev, "profile 0x%02x cd_rom\n", profile);
+                        cd_cd_rom = 1;
+                        break;
+                case 0x09:
+                        info(udev, "profile 0x%02x cd_r\n", profile);
+                        cd_cd_r = 1;
+                        break;
+                case 0x0A:
+                        info(udev, "profile 0x%02x cd_rw\n", profile);
+                        cd_cd_rw = 1;
+                        break;
+                case 0x10:
+                        info(udev, "profile 0x%02x dvd_rom\n", profile);
+                        cd_dvd_rom = 1;
+                        break;
+                case 0x12:
+                        info(udev, "profile 0x%02x dvd_ram\n", profile);
+                        cd_dvd_ram = 1;
+                        break;
+                case 0x13:
+                case 0x14:
+                        info(udev, "profile 0x%02x dvd_rw\n", profile);
+                        cd_dvd_rw = 1;
+                        break;
+                case 0x1B:
+                        info(udev, "profile 0x%02x dvd_plus_r\n", profile);
+                        cd_dvd_plus_r = 1;
+                        break;
+                case 0x1A:
+                        info(udev, "profile 0x%02x dvd_plus_rw\n", profile);
+                        cd_dvd_plus_rw = 1;
+                        break;
+                case 0x2A:
+                        info(udev, "profile 0x%02x dvd_plus_rw_dl\n", profile);
+                        cd_dvd_plus_rw_dl = 1;
+                        break;
+                case 0x2B:
+                        info(udev, "profile 0x%02x dvd_plus_r_dl\n", profile);
+                        cd_dvd_plus_r_dl = 1;
+                        break;
+                case 0x40:
+                        cd_bd = 1;
+                        info(udev, "profile 0x%02x bd\n", profile);
+                        break;
+                case 0x41:
+                case 0x42:
+                        cd_bd_r = 1;
+                        info(udev, "profile 0x%02x bd_r\n", profile);
+                        break;
+                case 0x43:
+                        cd_bd_re = 1;
+                        info(udev, "profile 0x%02x bd_re\n", profile);
+                        break;
+                case 0x50:
+                        cd_hddvd = 1;
+                        info(udev, "profile 0x%02x hddvd\n", profile);
+                        break;
+                case 0x51:
+                        cd_hddvd_r = 1;
+                        info(udev, "profile 0x%02x hddvd_r\n", profile);
+                        break;
+                case 0x52:
+                        cd_hddvd_rw = 1;
+                        info(udev, "profile 0x%02x hddvd_rw\n", profile);
+                        break;
+                default:
+                        info(udev, "profile 0x%02x <ignored>\n", profile);
+                        break;
+                }
+        }
+        return 0;
+}
+
+/* returns 0 if media was detected */
+static int cd_profiles_old_mmc(struct udev *udev, int fd)
+{
+        struct scsi_cmd sc;
+        int err;
+
+        unsigned char header[32];
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x51);
+        scsi_cmd_set(udev, &sc, 8, sizeof(header));
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, header, sizeof(header));
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "READ DISC INFORMATION", err);
+                if (cd_media == 1) {
+                        info(udev, "no current profile, but disc is present; assuming CD-ROM\n");
+                        cd_media_cd_rom = 1;
+                        return 0;
+                } else {
+                        info(udev, "no current profile, assuming no media\n");
+                        return -1;
+                }
+        };
+
+        cd_media = 1;
+
+        if (header[2] & 16) {
+                cd_media_cd_rw = 1;
+                info(udev, "profile 0x0a media_cd_rw\n");
+        } else if ((header[2] & 3) < 2 && cd_cd_r) {
+                cd_media_cd_r = 1;
+                info(udev, "profile 0x09 media_cd_r\n");
+        } else {
+                cd_media_cd_rom = 1;
+                info(udev, "profile 0x08 media_cd_rom\n");
+        }
+        return 0;
+}
+
+/* returns 0 if media was detected */
+static int cd_profiles(struct udev *udev, int fd)
+{
+        struct scsi_cmd sc;
+        unsigned char features[65530];
+        unsigned int cur_profile = 0;
+        unsigned int len;
+        unsigned int i;
+        int err;
+        int ret;
+
+        ret = -1;
+
+        /* First query the current profile */
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x46);
+        scsi_cmd_set(udev, &sc, 8, 8);
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, features, 8);
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "GET CONFIGURATION", err);
+                /* handle pre-MMC2 drives which do not support GET CONFIGURATION */
+                if (SK(err) == 0x5 && ASC(err) == 0x20) {
+                        info(udev, "drive is pre-MMC2 and does not support 46h get configuration command\n");
+                        info(udev, "trying to work around the problem\n");
+                        ret = cd_profiles_old_mmc(udev, fd);
+                }
+                goto out;
+        }
+
+        cur_profile = features[6] << 8 | features[7];
+        if (cur_profile > 0) {
+                info(udev, "current profile 0x%02x\n", cur_profile);
+                feature_profile_media (udev, cur_profile);
+                ret = 0; /* we have media */
+        } else {
+                info(udev, "no current profile, assuming no media\n");
+        }
+
+        len = features[0] << 24 | features[1] << 16 | features[2] << 8 | features[3];
+        info(udev, "GET CONFIGURATION: size of features buffer 0x%04x\n", len);
+
+        if (len > sizeof(features)) {
+                info(udev, "can not get features in a single query, truncating\n");
+                len = sizeof(features);
+        } else if (len <= 8) {
+                len = sizeof(features);
+        }
+
+        /* Now get the full feature buffer */
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x46);
+        scsi_cmd_set(udev, &sc, 7, ( len >> 8 ) & 0xff);
+        scsi_cmd_set(udev, &sc, 8, len & 0xff);
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, features, len);
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "GET CONFIGURATION", err);
+                return -1;
+        }
+
+        /* parse the length once more, in case the drive decided to have other features suddenly :) */
+        len = features[0] << 24 | features[1] << 16 | features[2] << 8 | features[3];
+        info(udev, "GET CONFIGURATION: size of features buffer 0x%04x\n", len);
+
+        if (len > sizeof(features)) {
+                info(udev, "can not get features in a single query, truncating\n");
+                len = sizeof(features);
+        }
+
+        /* device features */
+        for (i = 8; i+4 < len; i += (4 + features[i+3])) {
+                unsigned int feature;
+
+                feature = features[i] << 8 | features[i+1];
+
+                switch (feature) {
+                case 0x00:
+                        info(udev, "GET CONFIGURATION: feature 'profiles', with %i entries\n", features[i+3] / 4);
+                        feature_profiles(udev, &features[i]+4, features[i+3]);
+                        break;
+                default:
+                        info(udev, "GET CONFIGURATION: feature 0x%04x <ignored>, with 0x%02x bytes\n", feature, features[i+3]);
+                        break;
+                }
+        }
+out:
+        return ret;
+}
+
+static int cd_media_info(struct udev *udev, int fd)
+{
+        struct scsi_cmd sc;
+        unsigned char header[32];
+        static const char *media_status[] = {
+                "blank",
+                "appendable",
+                "complete",
+                "other"
+        };
+        int err;
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x51);
+        scsi_cmd_set(udev, &sc, 8, sizeof(header) & 0xff);
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, header, sizeof(header));
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "READ DISC INFORMATION", err);
+                return -1;
+        };
+
+        cd_media = 1;
+        info(udev, "disk type %02x\n", header[8]);
+        info(udev, "hardware reported media status: %s\n", media_status[header[2] & 3]);
+
+        /* exclude plain CDROM, some fake cdroms return 0 for "blank" media here */
+        if (!cd_media_cd_rom)
+                cd_media_state = media_status[header[2] & 3];
+
+        /* fresh DVD-RW in restricted overwite mode reports itself as
+         * "appendable"; change it to "blank" to make it consistent with what
+         * gets reported after blanking, and what userspace expects  */
+        if (cd_media_dvd_rw_ro && (header[2] & 3) == 1)
+                cd_media_state = media_status[0];
+
+        /* DVD+RW discs (and DVD-RW in restricted mode) once formatted are
+         * always "complete", DVD-RAM are "other" or "complete" if the disc is
+         * write protected; we need to check the contents if it is blank */
+        if ((cd_media_dvd_rw_ro || cd_media_dvd_plus_rw || cd_media_dvd_plus_rw_dl || cd_media_dvd_ram) && (header[2] & 3) > 1) {
+                unsigned char buffer[32 * 2048];
+                unsigned char result, len;
+                int block, offset;
+
+                if (cd_media_dvd_ram) {
+                        /* a write protected dvd-ram may report "complete" status */
+
+                        unsigned char dvdstruct[8];
+                        unsigned char format[12];
+
+                        scsi_cmd_init(udev, &sc);
+                        scsi_cmd_set(udev, &sc, 0, 0xAD);
+                        scsi_cmd_set(udev, &sc, 7, 0xC0);
+                        scsi_cmd_set(udev, &sc, 9, sizeof(dvdstruct));
+                        scsi_cmd_set(udev, &sc, 11, 0);
+                        err = scsi_cmd_run(udev, &sc, fd, dvdstruct, sizeof(dvdstruct));
+                        if ((err != 0)) {
+                                info_scsi_cmd_err(udev, "READ DVD STRUCTURE", err);
+                                return -1;
+                        }
+                        if (dvdstruct[4] & 0x02) {
+                                cd_media_state = media_status[2];
+                                info(udev, "write-protected DVD-RAM media inserted\n");
+                                goto determined;
+                        }
+
+                        /* let's make sure we don't try to read unformatted media */
+                        scsi_cmd_init(udev, &sc);
+                        scsi_cmd_set(udev, &sc, 0, 0x23);
+                        scsi_cmd_set(udev, &sc, 8, sizeof(format));
+                        scsi_cmd_set(udev, &sc, 9, 0);
+                        err = scsi_cmd_run(udev, &sc, fd, format, sizeof(format));
+                        if ((err != 0)) {
+                                info_scsi_cmd_err(udev, "READ DVD FORMAT CAPACITIES", err);
+                                return -1;
+                        }
+
+                        len = format[3];
+                        if (len & 7 || len < 16) {
+                                info(udev, "invalid format capacities length\n");
+                                return -1;
+                        }
+
+                        switch(format[8] & 3) {
+                            case 1:
+                                info(udev, "unformatted DVD-RAM media inserted\n");
+                                /* This means that last format was interrupted
+                                 * or failed, blank dvd-ram discs are factory
+                                 * formatted. Take no action here as it takes
+                                 * quite a while to reformat a dvd-ram and it's
+                                 * not automatically started */
+                                goto determined;
+
+                            case 2:
+                                info(udev, "formatted DVD-RAM media inserted\n");
+                                break;
+
+                            case 3:
+                                cd_media = 0; //return no media
+                                info(udev, "format capacities returned no media\n");
+                                return -1;
+                        }
+                }
+
+                /* Take a closer look at formatted media (unformatted DVD+RW
+                 * has "blank" status", DVD-RAM was examined earlier) and check
+                 * for ISO and UDF PVDs or a fs superblock presence and do it
+                 * in one ioctl (we need just sectors 0 and 16) */
+                scsi_cmd_init(udev, &sc);
+                scsi_cmd_set(udev, &sc, 0, 0x28);
+                scsi_cmd_set(udev, &sc, 5, 0);
+                scsi_cmd_set(udev, &sc, 8, 32);
+                scsi_cmd_set(udev, &sc, 9, 0);
+                err = scsi_cmd_run(udev, &sc, fd, buffer, sizeof(buffer));
+                if ((err != 0)) {
+                        cd_media = 0;
+                        info_scsi_cmd_err(udev, "READ FIRST 32 BLOCKS", err);
+                        return -1;
+                }
+
+                /* if any non-zero data is found in sector 16 (iso and udf) or
+                 * eventually 0 (fat32 boot sector, ext2 superblock, etc), disc
+                 * is assumed non-blank */
+                result = 0;
+
+                for (block = 32768; block >= 0 && !result; block -= 32768) {
+                        offset = block;
+                        while (offset < (block + 2048) && !result) {
+                                result = buffer [offset];
+                                offset++;
+                        }
+                }
+
+                if (!result) {
+                        cd_media_state = media_status[0];
+                        info(udev, "no data in blocks 0 or 16, assuming blank\n");
+                } else {
+                        info(udev, "data in blocks 0 or 16, assuming complete\n");
+                }
+        }
+
+determined:
+        /* "other" is e. g. DVD-RAM, can't append sessions there; DVDs in
+         * restricted overwrite mode can never append, only in sequential mode */
+        if ((header[2] & 3) < 2 && !cd_media_dvd_rw_ro)
+                cd_media_session_next = header[10] << 8 | header[5];
+        cd_media_session_count = header[9] << 8 | header[4];
+        cd_media_track_count = header[11] << 8 | header[6];
+
+        return 0;
+}
+
+static int cd_media_toc(struct udev *udev, int fd)
+{
+        struct scsi_cmd sc;
+        unsigned char header[12];
+        unsigned char toc[65536];
+        unsigned int len, i, num_tracks;
+        unsigned char *p;
+        int err;
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x43);
+        scsi_cmd_set(udev, &sc, 6, 1);
+        scsi_cmd_set(udev, &sc, 8, sizeof(header) & 0xff);
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, header, sizeof(header));
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "READ TOC", err);
+                return -1;
+        }
+
+        len = (header[0] << 8 | header[1]) + 2;
+        info(udev, "READ TOC: len: %d, start track: %d, end track: %d\n", len, header[2], header[3]);
+        if (len > sizeof(toc))
+                return -1;
+        if (len < 2)
+                return -1;
+        /* 2: first track, 3: last track */
+        num_tracks = header[3] - header[2] + 1;
+
+        /* empty media has no tracks */
+        if (len < 8)
+                return 0;
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x43);
+        scsi_cmd_set(udev, &sc, 6, header[2]); /* First Track/Session Number */
+        scsi_cmd_set(udev, &sc, 7, (len >> 8) & 0xff);
+        scsi_cmd_set(udev, &sc, 8, len & 0xff);
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, toc, len);
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "READ TOC (tracks)", err);
+                return -1;
+        }
+
+        /* Take care to not iterate beyond the last valid track as specified in
+         * the TOC, but also avoid going beyond the TOC length, just in case
+         * the last track number is invalidly large */
+        for (p = toc+4, i = 4; i < len-8 && num_tracks > 0; i += 8, p += 8, --num_tracks) {
+                unsigned int block;
+                unsigned int is_data_track;
+
+                is_data_track = (p[1] & 0x04) != 0;
+
+                block = p[4] << 24 | p[5] << 16 | p[6] << 8 | p[7];
+                info(udev, "track=%u info=0x%x(%s) start_block=%u\n",
+                     p[2], p[1] & 0x0f, is_data_track ? "data":"audio", block);
+
+                if (is_data_track)
+                        cd_media_track_count_data++;
+                else
+                        cd_media_track_count_audio++;
+        }
+
+        scsi_cmd_init(udev, &sc);
+        scsi_cmd_set(udev, &sc, 0, 0x43);
+        scsi_cmd_set(udev, &sc, 2, 1); /* Session Info */
+        scsi_cmd_set(udev, &sc, 8, sizeof(header));
+        scsi_cmd_set(udev, &sc, 9, 0);
+        err = scsi_cmd_run(udev, &sc, fd, header, sizeof(header));
+        if ((err != 0)) {
+                info_scsi_cmd_err(udev, "READ TOC (multi session)", err);
+                return -1;
+        }
+        len = header[4+4] << 24 | header[4+5] << 16 | header[4+6] << 8 | header[4+7];
+        info(udev, "last track %u starts at block %u\n", header[4+2], len);
+        cd_media_session_last_offset = (unsigned long long int)len * 2048;
+        return 0;
+}
+
+int main(int argc, char *argv[])
+{
+        struct udev *udev;
+        static const struct option options[] = {
+                { "lock-media", no_argument, NULL, 'l' },
+                { "unlock-media", no_argument, NULL, 'u' },
+                { "eject-media", no_argument, NULL, 'e' },
+                { "debug", no_argument, NULL, 'd' },
+                { "help", no_argument, NULL, 'h' },
+                {}
+        };
+        bool eject = false;
+        bool lock = false;
+        bool unlock = false;
+        const char *node = NULL;
+        int fd = -1;
+        int cnt;
+        int rc = 0;
+
+        udev = udev_new();
+        if (udev == NULL)
+                goto exit;
+
+        udev_log_init("cdrom_id");
+        udev_set_log_fn(udev, log_fn);
+
+        while (1) {
+                int option;
+
+                option = getopt_long(argc, argv, "deluh", options, NULL);
+                if (option == -1)
+                        break;
+
+                switch (option) {
+                case 'l':
+                        lock = true;
+                        break;
+                case 'u':
+                        unlock = true;
+                        break;
+                case 'e':
+                        eject = true;
+                        break;
+                case 'd':
+                        debug = true;
+                        if (udev_get_log_priority(udev) < LOG_INFO)
+                                udev_set_log_priority(udev, LOG_INFO);
+                        break;
+                case 'h':
+                        printf("Usage: cdrom_id [options] <device>\n"
+                               "  --lock-media    lock the media (to enable eject request events)\n"
+                               "  --unlock-media  unlock the media\n"
+                               "  --eject-media   eject the media\n"
+                               "  --debug         debug to stderr\n"
+                               "  --help          print this help text\n\n");
+                        goto exit;
+                default:
+                        rc = 1;
+                        goto exit;
+                }
+        }
+
+        node = argv[optind];
+        if (!node) {
+                err(udev, "no device\n");
+                fprintf(stderr, "no device\n");
+                rc = 1;
+                goto exit;
+        }
+
+        srand((unsigned int)getpid());
+        for (cnt = 20; cnt > 0; cnt--) {
+                struct timespec duration;
+
+                fd = open(node, O_RDONLY|O_NONBLOCK|(is_mounted(node) ? 0 : O_EXCL));
+                if (fd >= 0 || errno != EBUSY)
+                        break;
+                duration.tv_sec = 0;
+                duration.tv_nsec = (100 * 1000 * 1000) + (rand() % 100 * 1000 * 1000);
+                nanosleep(&duration, NULL);
+        }
+        if (fd < 0) {
+                info(udev, "unable to open '%s'\n", node);
+                fprintf(stderr, "unable to open '%s'\n", node);
+                rc = 1;
+                goto exit;
+        }
+        info(udev, "probing: '%s'\n", node);
+
+        /* same data as original cdrom_id */
+        if (cd_capability_compat(udev, fd) < 0) {
+                rc = 1;
+                goto exit;
+        }
+
+        /* check for media - don't bail if there's no media as we still need to
+         * to read profiles */
+        cd_media_compat(udev, fd);
+
+        /* check if drive talks MMC */
+        if (cd_inquiry(udev, fd) < 0)
+                goto work;
+
+        /* read drive and possibly current profile */
+        if (cd_profiles(udev, fd) != 0)
+                goto work;
+
+        /* at this point we are guaranteed to have media in the drive - find out more about it */
+
+        /* get session/track info */
+        cd_media_toc(udev, fd);
+
+        /* get writable media state */
+        cd_media_info(udev, fd);
+
+work:
+        /* lock the media, so we enable eject button events */
+        if (lock && cd_media) {
+                info(udev, "PREVENT_ALLOW_MEDIUM_REMOVAL (lock)\n");
+                media_lock(udev, fd, true);
+        }
+
+        if (unlock && cd_media) {
+                info(udev, "PREVENT_ALLOW_MEDIUM_REMOVAL (unlock)\n");
+                media_lock(udev, fd, false);
+        }
+
+        if (eject) {
+                info(udev, "PREVENT_ALLOW_MEDIUM_REMOVAL (unlock)\n");
+                media_lock(udev, fd, false);
+                info(udev, "START_STOP_UNIT (eject)\n");
+                media_eject(udev, fd);
+        }
+
+        printf("ID_CDROM=1\n");
+        if (cd_cd_rom)
+                printf("ID_CDROM_CD=1\n");
+        if (cd_cd_r)
+                printf("ID_CDROM_CD_R=1\n");
+        if (cd_cd_rw)
+                printf("ID_CDROM_CD_RW=1\n");
+        if (cd_dvd_rom)
+                printf("ID_CDROM_DVD=1\n");
+        if (cd_dvd_r)
+                printf("ID_CDROM_DVD_R=1\n");
+        if (cd_dvd_rw)
+                printf("ID_CDROM_DVD_RW=1\n");
+        if (cd_dvd_ram)
+                printf("ID_CDROM_DVD_RAM=1\n");
+        if (cd_dvd_plus_r)
+                printf("ID_CDROM_DVD_PLUS_R=1\n");
+        if (cd_dvd_plus_rw)
+                printf("ID_CDROM_DVD_PLUS_RW=1\n");
+        if (cd_dvd_plus_r_dl)
+                printf("ID_CDROM_DVD_PLUS_R_DL=1\n");
+        if (cd_dvd_plus_rw_dl)
+                printf("ID_CDROM_DVD_PLUS_RW_DL=1\n");
+        if (cd_bd)
+                printf("ID_CDROM_BD=1\n");
+        if (cd_bd_r)
+                printf("ID_CDROM_BD_R=1\n");
+        if (cd_bd_re)
+                printf("ID_CDROM_BD_RE=1\n");
+        if (cd_hddvd)
+                printf("ID_CDROM_HDDVD=1\n");
+        if (cd_hddvd_r)
+                printf("ID_CDROM_HDDVD_R=1\n");
+        if (cd_hddvd_rw)
+                printf("ID_CDROM_HDDVD_RW=1\n");
+        if (cd_mo)
+                printf("ID_CDROM_MO=1\n");
+        if (cd_mrw)
+                printf("ID_CDROM_MRW=1\n");
+        if (cd_mrw_w)
+                printf("ID_CDROM_MRW_W=1\n");
+
+        if (cd_media)
+                printf("ID_CDROM_MEDIA=1\n");
+        if (cd_media_mo)
+                printf("ID_CDROM_MEDIA_MO=1\n");
+        if (cd_media_mrw)
+                printf("ID_CDROM_MEDIA_MRW=1\n");
+        if (cd_media_mrw_w)
+                printf("ID_CDROM_MEDIA_MRW_W=1\n");
+        if (cd_media_cd_rom)
+                printf("ID_CDROM_MEDIA_CD=1\n");
+        if (cd_media_cd_r)
+                printf("ID_CDROM_MEDIA_CD_R=1\n");
+        if (cd_media_cd_rw)
+                printf("ID_CDROM_MEDIA_CD_RW=1\n");
+        if (cd_media_dvd_rom)
+                printf("ID_CDROM_MEDIA_DVD=1\n");
+        if (cd_media_dvd_r)
+                printf("ID_CDROM_MEDIA_DVD_R=1\n");
+        if (cd_media_dvd_ram)
+                printf("ID_CDROM_MEDIA_DVD_RAM=1\n");
+        if (cd_media_dvd_rw)
+                printf("ID_CDROM_MEDIA_DVD_RW=1\n");
+        if (cd_media_dvd_plus_r)
+                printf("ID_CDROM_MEDIA_DVD_PLUS_R=1\n");
+        if (cd_media_dvd_plus_rw)
+                printf("ID_CDROM_MEDIA_DVD_PLUS_RW=1\n");
+        if (cd_media_dvd_plus_rw_dl)
+                printf("ID_CDROM_MEDIA_DVD_PLUS_RW_DL=1\n");
+        if (cd_media_dvd_plus_r_dl)
+                printf("ID_CDROM_MEDIA_DVD_PLUS_R_DL=1\n");
+        if (cd_media_bd)
+                printf("ID_CDROM_MEDIA_BD=1\n");
+        if (cd_media_bd_r)
+                printf("ID_CDROM_MEDIA_BD_R=1\n");
+        if (cd_media_bd_re)
+                printf("ID_CDROM_MEDIA_BD_RE=1\n");
+        if (cd_media_hddvd)
+                printf("ID_CDROM_MEDIA_HDDVD=1\n");
+        if (cd_media_hddvd_r)
+                printf("ID_CDROM_MEDIA_HDDVD_R=1\n");
+        if (cd_media_hddvd_rw)
+                printf("ID_CDROM_MEDIA_HDDVD_RW=1\n");
+
+        if (cd_media_state != NULL)
+                printf("ID_CDROM_MEDIA_STATE=%s\n", cd_media_state);
+        if (cd_media_session_next > 0)
+                printf("ID_CDROM_MEDIA_SESSION_NEXT=%d\n", cd_media_session_next);
+        if (cd_media_session_count > 0)
+                printf("ID_CDROM_MEDIA_SESSION_COUNT=%d\n", cd_media_session_count);
+        if (cd_media_session_count > 1 && cd_media_session_last_offset > 0)
+                printf("ID_CDROM_MEDIA_SESSION_LAST_OFFSET=%llu\n", cd_media_session_last_offset);
+        if (cd_media_track_count > 0)
+                printf("ID_CDROM_MEDIA_TRACK_COUNT=%d\n", cd_media_track_count);
+        if (cd_media_track_count_audio > 0)
+                printf("ID_CDROM_MEDIA_TRACK_COUNT_AUDIO=%d\n", cd_media_track_count_audio);
+        if (cd_media_track_count_data > 0)
+                printf("ID_CDROM_MEDIA_TRACK_COUNT_DATA=%d\n", cd_media_track_count_data);
+exit:
+        if (fd >= 0)
+                close(fd);
+        udev_unref(udev);
+        udev_log_close();
+        return rc;
+}