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#include <kernel/arch/i386/ata.h>
#include <kernel/arch/i386/driver/ps2.h>
#include <kernel/arch/i386/driver/serial.h>
#include <kernel/mem/virt.h>
#include <kernel/panic.h>
#include <kernel/proc.h>
#include <kernel/util.h>
#include <kernel/vfs/root.h>
#include <shared/mem.h>
// TODO move to arch/
enum {
HANDLE_ROOT,
HANDLE_VGA,
HANDLE_COM1,
HANDLE_PS2,
HANDLE_ATA_ROOT,
HANDLE_ATA,
_SKIP = HANDLE_ATA + 4,
};
static bool exacteq(struct vfs_request *req, const char *str) {
int len = strlen(str);
assert(req->input.kern);
return req->input.len == len && !memcmp(req->input.buf_kern, str, len);
}
/* truncates the length */
static void req_preprocess(struct vfs_request *req, int max_len) {
// max_len is signed because req->*.len are signed too
// potential place for VULNs to occur - arbitrary kernel reads etc
if (req->offset < 0) {
// TODO negative offsets
req->offset = 0;
}
if (req->offset >= max_len) {
req->input.len = 0;
req->output.len = 0;
req->offset = max_len;
return;
}
if (req->input.len < 0) req->input.len = 0;
if (req->output.len < 0) req->output.len = 0;
req->input.len = min(req->input.len, max_len - req->offset);
req->output.len = min(req->output.len, max_len - req->offset);
assert(req->input.len >= 0);
assert(req->output.len >= 0);
assert(req->input.len + req->offset <= max_len);
assert(req->input.len + req->offset <= max_len);
}
static int handle(struct vfs_request *req, bool *ready) {
switch (req->type) {
case VFSOP_OPEN:
if (exacteq(req, "/")) return HANDLE_ROOT;
if (exacteq(req, "/vga")) return HANDLE_VGA;
if (exacteq(req, "/com1")) return HANDLE_COM1;
if (exacteq(req, "/ps2")) return HANDLE_PS2;
if (exacteq(req, "/ata/")) return HANDLE_ATA_ROOT;
if (exacteq(req, "/ata/0"))
return ata_available(0) ? HANDLE_ATA+0 : -1;
if (exacteq(req, "/ata/1"))
return ata_available(1) ? HANDLE_ATA+1 : -1;
if (exacteq(req, "/ata/2"))
return ata_available(2) ? HANDLE_ATA+2 : -1;
if (exacteq(req, "/ata/3"))
return ata_available(3) ? HANDLE_ATA+3 : -1;
return -1;
case VFSOP_READ:
switch (req->id) {
case HANDLE_ROOT: {
// TODO document directory read format
const char src[] =
"vga\0"
"com1\0"
"ps2\0"
"ata/";
if (req->output.len < 0) return 0; // is this needed? TODO make that a size_t or something
int len = min((size_t) req->output.len, sizeof(src));
virt_cpy_to(req->caller->pages, req->output.buf, src, len);
return len;
}
case HANDLE_VGA: {
char *vga = (void*)0xB8000;
req_preprocess(req, 80*25*2);
virt_cpy_to(req->caller->pages, req->output.buf,
vga + req->offset, req->output.len);
return req->output.len;
}
case HANDLE_COM1: {
struct virt_iter iter;
virt_iter_new(&iter, req->output.buf, req->output.len,
req->caller->pages, true, false);
while (virt_iter_next(&iter))
serial_read(iter.frag, iter.frag_len);
return iter.prior;
}
case HANDLE_PS2: {
if (!ps2_ready()) {
*ready = false;
req->caller->state = PS_WAITS4IRQ;
/* not copying any memory, both sides point to the same
* struct. this line's only there so i don't depend on
* struct alignment always staying the same */
req->caller->waits4irq.req = *req;
req->caller->waits4irq.ready = ps2_ready;
return -1;
}
uint8_t buf[16];
size_t len = ps2_read(buf, sizeof buf);
virt_cpy_to(req->caller->pages, req->output.buf, buf, len);
return len;
}
case HANDLE_ATA_ROOT: {
// TODO offset
char list[8] = {};
size_t len = 0;
for (int i = 0; i < 4; i++) {
if (ata_available(i)) {
list[len] = '0' + i;
len += 2;
}
}
len = min((size_t) req->output.len, len);
virt_cpy_to(req->caller->pages, req->output.buf, list, len);
return len;
}
case HANDLE_ATA: case HANDLE_ATA+1:
case HANDLE_ATA+2: case HANDLE_ATA+3: {
if (req->offset < 0) return 0;
char buf[512];
uint32_t sector = req->offset / 512;
int len = min(req->output.len, 512 - (req->offset & 511));
ata_read(req->id - HANDLE_ATA, sector, buf);
virt_cpy_to(req->caller->pages, req->output.buf, buf, len);
return len;
}
default: panic_invalid_state();
}
case VFSOP_WRITE:
switch (req->id) {
case HANDLE_ROOT: return -1;
case HANDLE_VGA: {
void *vga = (void*)0xB8000;
req_preprocess(req, 80*25*2);
virt_cpy_from(req->caller->pages, vga + req->offset,
req->input.buf, req->input.len);
return req->input.len;
}
case HANDLE_COM1: {
struct virt_iter iter;
virt_iter_new(&iter, req->input.buf, req->input.len,
req->caller->pages, true, false);
while (virt_iter_next(&iter))
serial_write(iter.frag, iter.frag_len);
return iter.prior;
}
case HANDLE_ATA_ROOT: return -1;
// TODO don't panic on ps2 reads
default: panic_invalid_state();
}
default: panic_invalid_state();
}
}
int vfs_root_handler(struct vfs_request *req) {
bool ready = true;
int ret = handle(req, &ready);
if (ready)
return vfs_request_finish(req, ret);
else
return -1;
}
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