systemd/src/udev/udev-builtin-usb_id.c

/*
 * USB device properties and persistent device path
 *
 * Copyright (c) 2005 SUSE Linux Products GmbH, Germany
 *   Author: Hannes Reinecke <hare@suse.de>
 *
 * Copyright (C) 2005-2011 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/>.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>

#include "udev.h"

static void set_usb_iftype(char *to, int if_class_num, size_t len)
{
        const char *type = "generic";

        switch (if_class_num) {
        case 1:
                type = "audio";
                break;
        case 2: /* CDC-Control */
                break;
        case 3:
                type = "hid";
                break;
        case 5: /* Physical */
                break;
        case 6:
                type = "media";
                break;
        case 7:
                type = "printer";
                break;
        case 8:
                type = "storage";
                break;
        case 9:
                type = "hub";
                break;
        case 0x0a: /* CDC-Data */
                break;
        case 0x0b: /* Chip/Smart Card */
                break;
        case 0x0d: /* Content Security */
                break;
        case 0x0e:
                type = "video";
                break;
        case 0xdc: /* Diagnostic Device */
                break;
        case 0xe0: /* Wireless Controller */
                break;
        case 0xfe: /* Application-specific */
                break;
        case 0xff: /* Vendor-specific */
                break;
        default:
                break;
        }
        strncpy(to, type, len);
        to[len-1] = '\0';
}

static int set_usb_mass_storage_ifsubtype(char *to, const char *from, size_t len)
{
        int type_num = 0;
        char *eptr;
        const char *type = "generic";

        type_num = strtoul(from, &eptr, 0);
        if (eptr != from) {
                switch (type_num) {
                case 2:
                        type = "atapi";
                        break;
                case 3:
                        type = "tape";
                        break;
                case 4: /* UFI */
                case 5: /* SFF-8070i */
                        type = "floppy";
                        break;
                case 1: /* RBC devices */
                        type = "rbc";
                        break;
                case 6: /* Transparent SPC-2 devices */
                        type = "scsi";
                        break;
                default:
                        break;
                }
        }
        util_strscpy(to, len, type);
        return type_num;
}

static void set_scsi_type(char *to, const char *from, size_t len)
{
        int type_num;
        char *eptr;
        const char *type = "generic";

        type_num = strtoul(from, &eptr, 0);
        if (eptr != from) {
                switch (type_num) {
                case 0:
                case 0xe:
                        type = "disk";
                        break;
                case 1:
                        type = "tape";
                        break;
                case 4:
                case 7:
                case 0xf:
                        type = "optical";
                        break;
                case 5:
                        type = "cd";
                        break;
                default:
                        break;
                }
        }
        util_strscpy(to, len, type);
}

#define USB_DT_DEVICE                        0x01
#define USB_DT_INTERFACE                0x04

static int dev_if_packed_info(struct udev_device *dev, char *ifs_str, size_t len)
{
        char *filename = NULL;
        int fd;
        ssize_t size;
        unsigned char buf[18 + 65535];
        unsigned int pos, strpos;
        struct usb_interface_descriptor {
                u_int8_t        bLength;
                u_int8_t        bDescriptorType;
                u_int8_t        bInterfaceNumber;
                u_int8_t        bAlternateSetting;
                u_int8_t        bNumEndpoints;
                u_int8_t        bInterfaceClass;
                u_int8_t        bInterfaceSubClass;
                u_int8_t        bInterfaceProtocol;
                u_int8_t        iInterface;
        } __attribute__((packed));
        int err = 0;

        if (asprintf(&filename, "%s/descriptors", udev_device_get_syspath(dev)) < 0) {
                err = -1;
                goto out;
        }
        fd = open(filename, O_RDONLY|O_CLOEXEC);
        if (fd < 0) {
                fprintf(stderr, "error opening USB device 'descriptors' file\n");
                err = -1;
                goto out;
        }
        size = read(fd, buf, sizeof(buf));
        close(fd);
        if (size < 18 || size == sizeof(buf)) {
                err = -1;
                goto out;
        }

        pos = 0;
        strpos = 0;
        ifs_str[0] = '\0';
        while (pos < sizeof(buf) && strpos+7 < len-2) {
                struct usb_interface_descriptor *desc;
                char if_str[8];

                desc = (struct usb_interface_descriptor *) &buf[pos];
                if (desc->bLength < 3)
                        break;
                pos += desc->bLength;

                if (desc->bDescriptorType != USB_DT_INTERFACE)
                        continue;

                if (snprintf(if_str, 8, ":%02x%02x%02x",
                             desc->bInterfaceClass,
                             desc->bInterfaceSubClass,
                             desc->bInterfaceProtocol) != 7)
                        continue;

                if (strstr(ifs_str, if_str) != NULL)
                        continue;

                memcpy(&ifs_str[strpos], if_str, 8),
                strpos += 7;
        }
        if (strpos > 0) {
                ifs_str[strpos++] = ':';
                ifs_str[strpos++] = '\0';
        }
out:
        free(filename);
        return err;
}

/*
 * A unique USB identification is generated like this:
 *
 * 1.) Get the USB device type from InterfaceClass and InterfaceSubClass
 * 2.) If the device type is 'Mass-Storage/SPC-2' or 'Mass-Storage/RBC'
 *     use the SCSI vendor and model as USB-Vendor and USB-model.
 * 3.) Otherwise use the USB manufacturer and product as
 *     USB-Vendor and USB-model. Any non-printable characters
 *     in those strings will be skipped; a slash '/' will be converted
 *     into a full stop '.'.
 * 4.) If that fails, too, we will use idVendor and idProduct
 *     as USB-Vendor and USB-model.
 * 5.) The USB identification is the USB-vendor and USB-model
 *     string concatenated with an underscore '_'.
 * 6.) If the device supplies a serial number, this number
 *     is concatenated with the identification with an underscore '_'.
 */
static int builtin_usb_id(struct udev_device *dev, int argc, char *argv[], bool test)
{
        char vendor_str[64];
        char vendor_str_enc[256];
        const char *vendor_id;
        char model_str[64];
        char model_str_enc[256];
        const char *product_id;
        char serial_str[UTIL_NAME_SIZE];
        char packed_if_str[UTIL_NAME_SIZE];
        char revision_str[64];
        char type_str[64];
        char instance_str[64];
        const char *ifnum = NULL;
        const char *driver = NULL;
        char serial[256];

        struct udev_device *dev_interface = NULL;
        struct udev_device *dev_usb = NULL;
        const char *if_class, *if_subclass;
        int if_class_num;
        int protocol = 0;
        size_t l;
        char *s;

        vendor_str[0] = '\0';
        model_str[0] = '\0';
        serial_str[0] = '\0';
        packed_if_str[0] = '\0';
        revision_str[0] = '\0';
        type_str[0] = '\0';
        instance_str[0] = '\0';

        /* shortcut, if we are called directly for a "usb_device" type */
        if (udev_device_get_devtype(dev) != NULL && strcmp(udev_device_get_devtype(dev), "usb_device") == 0) {
                dev_if_packed_info(dev, packed_if_str, sizeof(packed_if_str));
                dev_usb = dev;
                goto fallback;
        }

        /* usb interface directory */
        dev_interface = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
        if (dev_interface == NULL) {
                log_debug("unable to access usb_interface device of '%s'\n",
                     udev_device_get_syspath(dev));
                return EXIT_FAILURE;
        }

        ifnum = udev_device_get_sysattr_value(dev_interface, "bInterfaceNumber");
        driver = udev_device_get_sysattr_value(dev_interface, "driver");

        if_class = udev_device_get_sysattr_value(dev_interface, "bInterfaceClass");
        if (!if_class) {
                log_debug("%s: cannot get bInterfaceClass attribute\n",
                     udev_device_get_sysname(dev));
                return EXIT_FAILURE;
        }

        if_class_num = strtoul(if_class, NULL, 16);
        if (if_class_num == 8) {
                /* mass storage */
                if_subclass = udev_device_get_sysattr_value(dev_interface, "bInterfaceSubClass");
                if (if_subclass != NULL)
                        protocol = set_usb_mass_storage_ifsubtype(type_str, if_subclass, sizeof(type_str)-1);
        } else {
                set_usb_iftype(type_str, if_class_num, sizeof(type_str)-1);
        }

        log_debug("%s: if_class %d protocol %d\n",
             udev_device_get_syspath(dev_interface), if_class_num, protocol);

        /* usb device directory */
        dev_usb = udev_device_get_parent_with_subsystem_devtype(dev_interface, "usb", "usb_device");
        if (!dev_usb) {
                log_debug("unable to find parent 'usb' device of '%s'\n",
                     udev_device_get_syspath(dev));
                return EXIT_FAILURE;
        }

        /* all interfaces of the device in a single string */
        dev_if_packed_info(dev_usb, packed_if_str, sizeof(packed_if_str));

        /* mass storage : SCSI or ATAPI */
        if ((protocol == 6 || protocol == 2)) {
                struct udev_device *dev_scsi;
                const char *scsi_model, *scsi_vendor, *scsi_type, *scsi_rev;
                int host, bus, target, lun;

                /* get scsi device */
                dev_scsi = udev_device_get_parent_with_subsystem_devtype(dev, "scsi", "scsi_device");
                if (dev_scsi == NULL) {
                        log_debug("unable to find parent 'scsi' device of '%s'\n",
                             udev_device_get_syspath(dev));
                        goto fallback;
                }
                if (sscanf(udev_device_get_sysname(dev_scsi), "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4) {
                        log_debug("invalid scsi device '%s'\n", udev_device_get_sysname(dev_scsi));
                        goto fallback;
                }

                /* Generic SPC-2 device */
                scsi_vendor = udev_device_get_sysattr_value(dev_scsi, "vendor");
                if (!scsi_vendor) {
                        log_debug("%s: cannot get SCSI vendor attribute\n",
                             udev_device_get_sysname(dev_scsi));
                        goto fallback;
                }
                udev_util_encode_string(scsi_vendor, vendor_str_enc, sizeof(vendor_str_enc));
                util_replace_whitespace(scsi_vendor, vendor_str, sizeof(vendor_str)-1);
                util_replace_chars(vendor_str, NULL);

                scsi_model = udev_device_get_sysattr_value(dev_scsi, "model");
                if (!scsi_model) {
                        log_debug("%s: cannot get SCSI model attribute\n",
                             udev_device_get_sysname(dev_scsi));
                        goto fallback;
                }
                udev_util_encode_string(scsi_model, model_str_enc, sizeof(model_str_enc));
                util_replace_whitespace(scsi_model, model_str, sizeof(model_str)-1);
                util_replace_chars(model_str, NULL);

                scsi_type = udev_device_get_sysattr_value(dev_scsi, "type");
                if (!scsi_type) {
                        log_debug("%s: cannot get SCSI type attribute\n",
                             udev_device_get_sysname(dev_scsi));
                        goto fallback;
                }
                set_scsi_type(type_str, scsi_type, sizeof(type_str)-1);

                scsi_rev = udev_device_get_sysattr_value(dev_scsi, "rev");
                if (!scsi_rev) {
                        log_debug("%s: cannot get SCSI revision attribute\n",
                             udev_device_get_sysname(dev_scsi));
                        goto fallback;
                }
                util_replace_whitespace(scsi_rev, revision_str, sizeof(revision_str)-1);
                util_replace_chars(revision_str, NULL);

                /*
                 * some broken devices have the same identifiers
                 * for all luns, export the target:lun number
                 */
                sprintf(instance_str, "%d:%d", target, lun);
        }

fallback:
        vendor_id = udev_device_get_sysattr_value(dev_usb, "idVendor");
        product_id = udev_device_get_sysattr_value(dev_usb, "idProduct");

        /* fallback to USB vendor & device */
        if (vendor_str[0] == '\0') {
                const char *usb_vendor = NULL;

                usb_vendor = udev_device_get_sysattr_value(dev_usb, "manufacturer");
                if (!usb_vendor)
                        usb_vendor = vendor_id;
                if (!usb_vendor) {
                        log_debug("No USB vendor information available\n");
                        return EXIT_FAILURE;
                }
                udev_util_encode_string(usb_vendor, vendor_str_enc, sizeof(vendor_str_enc));
                util_replace_whitespace(usb_vendor, vendor_str, sizeof(vendor_str)-1);
                util_replace_chars(vendor_str, NULL);
        }

        if (model_str[0] == '\0') {
                const char *usb_model = NULL;

                usb_model = udev_device_get_sysattr_value(dev_usb, "product");
                if (!usb_model)
                        usb_model = product_id;
                if (!usb_model)
                        return EXIT_FAILURE;
                udev_util_encode_string(usb_model, model_str_enc, sizeof(model_str_enc));
                util_replace_whitespace(usb_model, model_str, sizeof(model_str)-1);
                util_replace_chars(model_str, NULL);
        }

        if (revision_str[0] == '\0') {
                const char *usb_rev;

                usb_rev = udev_device_get_sysattr_value(dev_usb, "bcdDevice");
                if (usb_rev) {
                        util_replace_whitespace(usb_rev, revision_str, sizeof(revision_str)-1);
                        util_replace_chars(revision_str, NULL);
                }
        }

        if (serial_str[0] == '\0') {
                const char *usb_serial;

                usb_serial = udev_device_get_sysattr_value(dev_usb, "serial");
                if (usb_serial) {
                        util_replace_whitespace(usb_serial, serial_str, sizeof(serial_str)-1);
                        util_replace_chars(serial_str, NULL);
                }
        }

        s = serial;
        l = util_strpcpyl(&s, sizeof(serial), vendor_str, "_", model_str, NULL);
        if (serial_str[0] != '\0')
                l = util_strpcpyl(&s, l, "_", serial_str, NULL);

        if (instance_str[0] != '\0')
                util_strpcpyl(&s, l, "-", instance_str, NULL);

        udev_builtin_add_property(dev, test, "ID_VENDOR", vendor_str);
        udev_builtin_add_property(dev, test, "ID_VENDOR_ENC", vendor_str_enc);
        udev_builtin_add_property(dev, test, "ID_VENDOR_ID", vendor_id);
        udev_builtin_add_property(dev, test, "ID_MODEL", model_str);
        udev_builtin_add_property(dev, test, "ID_MODEL_ENC", model_str_enc);
        udev_builtin_add_property(dev, test, "ID_MODEL_ID", product_id);
        udev_builtin_add_property(dev, test, "ID_REVISION", revision_str);
        udev_builtin_add_property(dev, test, "ID_SERIAL", serial);
        if (serial_str[0] != '\0')
                udev_builtin_add_property(dev, test, "ID_SERIAL_SHORT", serial_str);
        if (type_str[0] != '\0')
                udev_builtin_add_property(dev, test, "ID_TYPE", type_str);
        if (instance_str[0] != '\0')
                udev_builtin_add_property(dev, test, "ID_INSTANCE", instance_str);
        udev_builtin_add_property(dev, test, "ID_BUS", "usb");
        if (packed_if_str[0] != '\0')
                udev_builtin_add_property(dev, test, "ID_USB_INTERFACES", packed_if_str);
        if (ifnum != NULL)
                udev_builtin_add_property(dev, test, "ID_USB_INTERFACE_NUM", ifnum);
        if (driver != NULL)
                udev_builtin_add_property(dev, test, "ID_USB_DRIVER", driver);
        return EXIT_SUCCESS;
}

const struct udev_builtin udev_builtin_usb_id = {
        .name = "usb_id",
        .cmd = builtin_usb_id,
        .help = "usb device properties",
        .run_once = true,
};