1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/hal/linux/udev.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,148 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +/*
1.9 + * This file defines a wrapper around libudev so we can avoid
1.10 + * linking directly to it and use dlopen instead.
1.11 + */
1.12 +
1.13 +#ifndef HAL_LINUX_UDEV_H_
1.14 +#define HAL_LINUX_UDEV_H_
1.15 +
1.16 +#include <dlfcn.h>
1.17 +
1.18 +#include "mozilla/ArrayUtils.h"
1.19 +
1.20 +namespace mozilla {
1.21 +
1.22 +struct udev;
1.23 +struct udev_device;
1.24 +struct udev_enumerate;
1.25 +struct udev_list_entry;
1.26 +struct udev_monitor;
1.27 +
1.28 +class udev_lib {
1.29 + public:
1.30 + udev_lib() : lib(nullptr),
1.31 + udev(nullptr) {
1.32 + // Be careful about ABI compat! 0 -> 1 didn't change any
1.33 + // symbols this code relies on, per:
1.34 + // https://lists.fedoraproject.org/pipermail/devel/2012-June/168227.html
1.35 + const char* lib_names[] = {"libudev.so.0", "libudev.so.1"};
1.36 + // Check whether a library is already loaded so we don't load two
1.37 + // conflicting libs.
1.38 + for (unsigned i = 0; i < ArrayLength(lib_names); i++) {
1.39 + lib = dlopen(lib_names[i], RTLD_NOLOAD | RTLD_LAZY | RTLD_GLOBAL);
1.40 + if (lib) {
1.41 + break;
1.42 + }
1.43 + }
1.44 + // If nothing loads the first time through, it means no version of libudev
1.45 + // was already loaded.
1.46 + if (!lib) {
1.47 + for (unsigned i = 0; i < ArrayLength(lib_names); i++) {
1.48 + lib = dlopen(lib_names[i], RTLD_LAZY | RTLD_GLOBAL);
1.49 + if (lib) {
1.50 + break;
1.51 + }
1.52 + }
1.53 + }
1.54 + if (lib && LoadSymbols()) {
1.55 + udev = udev_new();
1.56 + }
1.57 + }
1.58 +
1.59 + ~udev_lib() {
1.60 + if (udev) {
1.61 + udev_unref(udev);
1.62 + }
1.63 +
1.64 + if (lib) {
1.65 + dlclose(lib);
1.66 + }
1.67 + }
1.68 +
1.69 + operator bool() {
1.70 + return udev;
1.71 + }
1.72 +
1.73 + private:
1.74 + bool LoadSymbols() {
1.75 +#define DLSYM(s) \
1.76 + do { \
1.77 + s = (typeof(s))dlsym(lib, #s); \
1.78 + if (!s) return false; \
1.79 + } while (0)
1.80 +
1.81 + DLSYM(udev_new);
1.82 + DLSYM(udev_unref);
1.83 + DLSYM(udev_device_unref);
1.84 + DLSYM(udev_device_new_from_syspath);
1.85 + DLSYM(udev_device_get_devnode);
1.86 + DLSYM(udev_device_get_parent_with_subsystem_devtype);
1.87 + DLSYM(udev_device_get_property_value);
1.88 + DLSYM(udev_device_get_action);
1.89 + DLSYM(udev_device_get_sysattr_value);
1.90 + DLSYM(udev_enumerate_new);
1.91 + DLSYM(udev_enumerate_unref);
1.92 + DLSYM(udev_enumerate_add_match_subsystem);
1.93 + DLSYM(udev_enumerate_scan_devices);
1.94 + DLSYM(udev_enumerate_get_list_entry);
1.95 + DLSYM(udev_list_entry_get_next);
1.96 + DLSYM(udev_list_entry_get_name);
1.97 + DLSYM(udev_monitor_new_from_netlink);
1.98 + DLSYM(udev_monitor_filter_add_match_subsystem_devtype);
1.99 + DLSYM(udev_monitor_enable_receiving);
1.100 + DLSYM(udev_monitor_get_fd);
1.101 + DLSYM(udev_monitor_receive_device);
1.102 + DLSYM(udev_monitor_unref);
1.103 +#undef DLSYM
1.104 + return true;
1.105 + }
1.106 +
1.107 + void* lib;
1.108 +
1.109 + public:
1.110 + struct udev* udev;
1.111 +
1.112 + // Function pointers returned from dlsym.
1.113 + struct udev* (*udev_new)(void);
1.114 + void (*udev_unref)(struct udev*);
1.115 +
1.116 + void (*udev_device_unref)(struct udev_device*);
1.117 + struct udev_device* (*udev_device_new_from_syspath)(struct udev*,
1.118 + const char*);
1.119 + const char* (*udev_device_get_devnode)(struct udev_device*);
1.120 + struct udev_device* (*udev_device_get_parent_with_subsystem_devtype)
1.121 + (struct udev_device*, const char*, const char*);
1.122 + const char* (*udev_device_get_property_value)(struct udev_device*,
1.123 + const char*);
1.124 + const char* (*udev_device_get_action)(struct udev_device*);
1.125 + const char* (*udev_device_get_sysattr_value)(struct udev_device*,
1.126 + const char*);
1.127 +
1.128 + struct udev_enumerate* (*udev_enumerate_new)(struct udev*);
1.129 + void (*udev_enumerate_unref)(struct udev_enumerate*);
1.130 + int (*udev_enumerate_add_match_subsystem)(struct udev_enumerate*,
1.131 + const char*);
1.132 + int (*udev_enumerate_scan_devices)(struct udev_enumerate*);
1.133 + struct udev_list_entry* (*udev_enumerate_get_list_entry)
1.134 + (struct udev_enumerate*);
1.135 +
1.136 + struct udev_list_entry* (*udev_list_entry_get_next)(struct udev_list_entry *);
1.137 + const char* (*udev_list_entry_get_name)(struct udev_list_entry*);
1.138 +
1.139 + struct udev_monitor* (*udev_monitor_new_from_netlink)(struct udev*,
1.140 + const char*);
1.141 + int (*udev_monitor_filter_add_match_subsystem_devtype)
1.142 + (struct udev_monitor*, const char*, const char*);
1.143 + int (*udev_monitor_enable_receiving)(struct udev_monitor*);
1.144 + int (*udev_monitor_get_fd)(struct udev_monitor*);
1.145 + struct udev_device* (*udev_monitor_receive_device)(struct udev_monitor*);
1.146 + void (*udev_monitor_unref)(struct udev_monitor*);
1.147 +};
1.148 +
1.149 +} // namespace mozilla
1.150 +
1.151 +#endif // HAL_LINUX_UDEV_H_
