void API_EXPORTED libusb_exit(struct libusb_context *ctx)
{
usbi_dbg("");
USBI_GET_CONTEXT(ctx);
if (ctx == usbi_default_context) {
usbi_mutex_static_lock(&default_context_lock);
if (--default_context_refcnt > 0) {
usbi_dbg("not destroying default context");
usbi_mutex_static_unlock(&default_context_lock);
return;
}
usbi_dbg("destroying default context");
usbi_default_context = NULL;
usbi_mutex_static_unlock(&default_context_lock);
}
if (!list_empty(&ctx->open_devs))
usbi_warn(ctx, "application left some devices open");
usbi_io_exit(ctx);
if (usbi_backend->exit)
usbi_backend->exit();
usbi_mutex_destroy(&ctx->open_devs_lock);
usbi_mutex_destroy(&ctx->usb_devs_lock);
free(ctx);
}
void linux_udev_hotplug_poll(void)
{
struct udev_device* udev_dev;
usbi_mutex_static_lock(&linux_hotplug_lock);
do {
udev_dev = udev_monitor_receive_device(udev_monitor);
if (udev_dev) {
usbi_dbg("Handling hotplug event from hotplug_poll");
udev_hotplug_event(udev_dev);
}
} while (udev_dev);
usbi_mutex_static_unlock(&linux_hotplug_lock);
}
static void *linux_udev_event_thread_main(void *arg)
{
struct udev_device* udev_dev;
struct pollfd fds = {.fd = udev_monitor_fd,
.events = POLLIN};
usbi_dbg("udev event thread entering.");
while (1 == poll(&fds, 1, -1)) {
if (NULL == udev_monitor || POLLIN != fds.revents) {
break;
}
usbi_mutex_static_lock(&linux_hotplug_lock);
udev_dev = udev_monitor_receive_device(udev_monitor);
if (udev_dev)
udev_hotplug_event(udev_dev);
usbi_mutex_static_unlock(&linux_hotplug_lock);
}
usbi_dbg("udev event thread exiting");
return NULL;
}
int API_EXPORTED libusb_init(libusb_context **context)
{
char *dbg = getenv("LIBUSB_DEBUG");
struct libusb_context *ctx;
int r = 0;
usbi_mutex_static_lock(&default_context_lock);
if (!context && usbi_default_context) {
usbi_dbg("reusing default context");
default_context_refcnt++;
usbi_mutex_static_unlock(&default_context_lock);
return 0;
}
ctx = malloc(sizeof(*ctx));
if (!ctx) {
r = LIBUSB_ERROR_NO_MEM;
goto err_unlock;
}
memset(ctx, 0, sizeof(*ctx));
if (dbg) {
ctx->debug = atoi(dbg);
if (ctx->debug)
ctx->debug_fixed = 1;
}
usbi_dbg("libusb-%d.%d.%d%s%s%s",
libusb_version_internal.major,
libusb_version_internal.minor,
libusb_version_internal.micro,
libusb_version_internal.rc,
libusb_version_internal.describe[0] ? " git:" : "",
libusb_version_internal.describe);
if (usbi_backend->init) {
r = usbi_backend->init(ctx);
if (r)
goto err_free_ctx;
}
usbi_mutex_init(&ctx->usb_devs_lock, NULL);
usbi_mutex_init(&ctx->open_devs_lock, NULL);
list_init(&ctx->usb_devs);
list_init(&ctx->open_devs);
r = usbi_io_init(ctx);
if (r < 0) {
if (usbi_backend->exit)
usbi_backend->exit();
goto err_destroy_mutex;
}
if (context) {
*context = ctx;
} else if (!usbi_default_context) {
usbi_dbg("created default context");
usbi_default_context = ctx;
default_context_refcnt++;
}
usbi_mutex_static_unlock(&default_context_lock);
return 0;
err_destroy_mutex:
usbi_mutex_destroy(&ctx->open_devs_lock);
usbi_mutex_destroy(&ctx->usb_devs_lock);
err_free_ctx:
free(ctx);
err_unlock:
usbi_mutex_static_unlock(&default_context_lock);
return r;
}
static int linux_netlink_read_message(void)
{
unsigned char buffer[1024];
struct iovec iov = {.iov_base = buffer, .iov_len = sizeof(buffer)};
struct msghdr meh = { .msg_iov=&iov, .msg_iovlen=1,
.msg_name=&snl, .msg_namelen=sizeof(snl) };
const char *sys_name = NULL;
uint8_t busnum, devaddr;
int detached, r;
size_t len;
/* read netlink message */
memset(buffer, 0, sizeof(buffer));
len = recvmsg(linux_netlink_socket, &meh, 0);
if (len < 32) {
if (errno != EAGAIN)
usbi_dbg("error recieving message from netlink");
return -1;
}
/* TODO -- authenticate this message is from the kernel or udevd */
r = linux_netlink_parse(buffer, len, &detached, &sys_name,
&busnum, &devaddr);
if (r)
return r;
usbi_dbg("netlink hotplug found device busnum: %hhu, devaddr: %hhu, sys_name: %s, removed: %s",
busnum, devaddr, sys_name, detached ? "yes" : "no");
/* signal device is available (or not) to all contexts */
if (detached)
linux_hotplug_disconnected(busnum, devaddr, sys_name);
else
linux_hotplug_enumerate(busnum, devaddr, sys_name);
return 0;
}
static void *linux_netlink_event_thread_main(void *arg)
{
struct pollfd fds = {.fd = linux_netlink_socket,
.events = POLLIN};
/* silence compiler warning */
(void) arg;
while (1 == poll(&fds, 1, -1)) {
if (POLLIN != fds.revents) {
break;
}
usbi_mutex_static_lock(&linux_hotplug_lock);
linux_netlink_read_message();
usbi_mutex_static_unlock(&linux_hotplug_lock);
}
return NULL;
}
void linux_netlink_hotplug_poll(void)
{
int r;
usbi_mutex_static_lock(&linux_hotplug_lock);
do {
r = linux_netlink_read_message();
} while (r == 0);
usbi_mutex_static_unlock(&linux_hotplug_lock);
}