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#include "sys/syscall.h"
#include "arch/x86_64/hal/obj.h"
#include "hal/memory.h"
#include "hal/smp.h"
#include "proc/process.h"
#include "jove.h"
#include "lib/printf.h"
#include "sys/link.h"
#include "sys/message.h"
int __syscall_generic_objpath(jove_owned_obj_t *objdir, size_t payload_bytes, void *payload_data, jove_owned_obj_t **retobj)
{
size_t bytes_needed = sizeof(struct syscall_generic_objpath);
CHECK_TOOSMALL(bytes_needed, payload_bytes,
"Message too small for payload.");
struct syscall_generic_objpath *payload = payload_data;
bytes_needed += payload->pathlen << 1;
CHECK_TOOSMALL(bytes_needed, payload_bytes,
"Message too small for object path.");
errno = 0;
*retobj = objdir_getobj(objdir, payload->path, payload->pathlen);
return errno;
}
int
_syscall_handle_generic(syscall_context_t *ctx)
{
pcb_t *pcb = obj_deref(ctx->pcb);
klogf("Process %i encountered stub syscall on object %P\n", pcb_getpid(pcb), ctx->header->path, ctx->header->pathlen);
return -EBADOBJ;
}
static const syscall_handle_t s_syscall_handles[128] = {
[JOVE_OBJ_UNTYPED] = _syscall_handle_untyped,
[JOVE_OBJ_OBJDIR] = _syscall_handle_objdir,
[JOVE_OBJ_PAGEDIR] = _syscall_handle_pagedir,
[JOVE_OBJ_PROCESSOR] = _syscall_handle_generic,
[JOVE_OBJ_REGION] = _syscall_handle_region,
[JOVE_OBJ_SHMEMORY] = _syscall_handle_generic,
[JOVE_OBJ_PCB] = _syscall_handle_pcb,
[JOVE_OBJ_INT_HANDLE] = _syscall_handle_generic,
[JOVE_OBJ_INITRD_FILE] = _syscall_handle_initrd_file,
[JOVE_OBJ_FRAMEBUFFER] = _syscall_handle_generic,
[JOVE_OBJ_VIRTTERM] = _syscall_handle_vtt,
[JOVE_OBJ_MESSAGE] = _syscall_handle_generic,
[JOVE_OBJ_LINK] = _syscall_handle_generic,
};
int
_syscall_handle_switch(syscall_context_t *ctx)
{
uint8_t target_type = obj_gettype(ctx->target.obj);
if(target_type == JOVE_OBJ_NONE) {
klogf("Tried to call syscall on NULL object %P\n", ctx->header->path, ctx->header->pathlen);
return -EBADOBJ;
}
if(target_type > 0x7F) {
return _syscall_handle_arch(ctx);
}
else {
syscall_handle_t call_handle = s_syscall_handles[target_type];
if(call_handle == NULL) {
klogf("Tried to call syscall on object %P which doesn't support syscalls!\n",
ctx->header->path, ctx->header->pathlen);
return -EBADOBJ;
}
else {
return call_handle(ctx);
}
}
}
int
syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
{
uint16_t *message_path = (uint16_t*)&message_path_raw;
if(message_pathlen > sizeof(uintmax_t) >> 1) {
return -EBADPATH;
}
syscall_context_t ctx;
ctx.lockstack.depth = 0;
int sysret = 0;
ctx.pcb = process_current();
pcb_t *pcb = obj_deref(ctx.pcb);
ctx.objdir = lockstack_push(&ctx.lockstack, obj_take(pcb_getrootdir(pcb)));
ctx.message = link_try_traverse_objdir(
ctx.objdir, &ctx.lockstack, message_pathlen, message_path);
if(ctx.message.obj == NULL) {
klogf("Process %i failed to get message %P : %s\n",
pcb_getpid(pcb), message_path, message_pathlen, errstr(errno));
sysret = -errno;
goto release_return;
}
if(obj_gettype(ctx.message.obj) != JOVE_OBJ_MESSAGE) {
klogf("Process %i tried to call syscall with invalid object %P\n",
pcb_getpid(pcb), message_path, message_pathlen);
sysret = -EBADOBJ;
goto release_return;
}
if((ctx.message.permissions & JOVE_PERM_READ) == 0) {
klogf("Process %i tried to call syscall with message object %P without read permissions\n",
pcb_getpid(pcb), message_path, message_pathlen);
sysret = -EPERM;
goto release_return;
}
jove_owned_obj_t *pagedir = lockstack_push(&ctx.lockstack, pcb_getpagedir(ctx.objdir));
uintptr_t message_vptr = message_unmap(ctx.message.obj, pagedir);
if(message_vptr == 0) {
klogf("Process %i tried to call syscall with unmapped message %P\n",
pcb_getpid(pcb), message_path, message_pathlen);
sysret = -EBADOBJ;
goto release_return;
}
size_t messagelen = 0x1000;
void *messagedata = (void*)message_getdata(ctx.message.obj);
struct syscall_header *header = messagedata;
size_t bytes_needed = sizeof(struct syscall_header) + header->pathlen * 2;
if(bytes_needed > messagelen) {
//Target path exceeds message length.
klogf("Process %i tried to call syscall with target path too big for message.\n", pcb_getpid(pcb));
sysret = -ETOOSMALL;
goto remap_return;
}
ctx.header = header;
ctx.bytes_left = messagelen - bytes_needed;
ctx.payload = (void*)((uintptr_t)header + bytes_needed);
ctx.target = link_try_traverse_objdir(
ctx.objdir, &ctx.lockstack, ctx.header->pathlen, ctx.header->path);
if(ctx.target.obj == 0) {
//Check if we're trying to reference objects we've already locked in this function.
//If we are, we should set it as the target regardless of lock,
//since we're the ones with the lock already.
if(ctx.header->pathlen == 1) {
if(ctx.header->path[0] == PCB_ROOTDIR_SELF_I)
ctx.target = (jove_perm_obj_t) { .permissions = 0xFF, .obj = ctx.pcb };
else if(ctx.header->path[0] == PCB_ROOTDIR_PAGEDIR_I)
ctx.target = (jove_perm_obj_t) { .permissions = 0xFF, .obj = pagedir };
else
goto fail_target_busy;
}else{
fail_target_busy:
//Could not find payload target in pcb rootdir.
klogf("Process %i tried to call syscall with bad target path %P : %s\n",
pcb_getpid(pcb), header->path, header->pathlen, errstr(errno));
sysret = -errno;
goto remap_return;
}
}
sysret = _syscall_handle_switch(&ctx);
remap_return:
message_map(ctx.message.obj, pagedir, message_vptr);
release_return:
lockstack_popall(&ctx.lockstack);
return sysret;
}
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