/*
* Open a directory.
* Params:
* state->ebx - address of user string containing path of directory to open
* state->ecx - length of path
*
* Returns: a file descriptor (>= 0) if successful,
* or an error code (< 0) if unsuccessful
*/
static int Sys_OpenDirectory(struct Interrupt_State *state) {
char *path;
struct File *file;
int rc = 0;
rc = get_path_from_registers(state->ebx, state->ecx, &path);
if(rc != 0) {
return rc;
}
rc = next_descriptor();
if(rc < 0) {
return rc;
}
Enable_Interrupts(); // duped from schulman
rc = Open_Directory(path, &file);
Disable_Interrupts();
Free(path);
if(rc >= 0) {
return add_file_to_descriptor_table(file);
} else {
return rc;
}
}
static int add_file_to_descriptor_table(struct File *file) {
int descriptor = next_descriptor();
if(descriptor >= 0) {
g_currentThread->userContext->file_descriptor_table[descriptor] = file;
}
return descriptor;
}
/*
* Including ones with alternate settings.
* Additionally it checks the descriptor's correctness.
* Descriptors often follow each other in a rather chaotical way.
*
* Device can have interfaces with chaotical numbers.
* For example, one real device has four interfaces with numbers #0, #2, #3, #8.
*/
int get_total_interfaces(const struct usb_config_descriptor *d)
{
struct usb_interface_descriptor *id = 0;
int total_len = 0;
int len = 0;
int ifcnt = 0;
int ok = 0;
if (!d) {
return -1;
}
ok = d->bLength == USB_DT_CONFIG_SIZE &&
d->bDescriptorType == USB_DT_CONFIG &&
d->wTotalLength > d->bLength;
if (!ok) {
return -2;
}
total_len = d->wTotalLength; // FIXME: le16_to_cpu
len = d->bLength;
id = first_interface(d, 0);
while (((char*)id - (char*)d) < total_len) {
int ifsz = get_interface_size(id);
if (ifsz) {
++ifcnt;
len += ifsz;
id = next_interface(id);
} else { // not an interface
len += id->bLength;
id = next_descriptor(id);
}
}
if (ifcnt < d->bNumInterfaces) { // yes, not !=, Logitech C500 fails otherwise
return -3;
}
if (len != d->wTotalLength) {
return -4;
}
return ((char*)id - (char*)d) == total_len ? ifcnt : -5;
}
struct usb_interface_descriptor *find_interface(
const struct usb_config_descriptor *d, int num, int altnum)
{
int cnt = get_total_interfaces(d);
struct usb_interface_descriptor *iface = cnt > 0 ? first_interface(d, 0) : 0;
int i = 0;
for (i = 0; i < cnt && iface;) {
if (!is_interface(iface)) {
iface = next_descriptor(iface);
} else if (iface->bInterfaceNumber == num && iface->bAlternateSetting == altnum) {
return iface;
} else {
iface = next_interface(iface);
++i;
}
}
return 0;
}
