Luna/kernel/src/sys/stat.cpp

#include "fs/VFS.h"
#include "interrupts/Context.h"
#include "std/errno.h"
#include "std/stdlib.h"
#include "sys/UserMemory.h"
#include "thread/Scheduler.h"

typedef unsigned short mode_t;
typedef unsigned long ino_t;

struct stat // FIXME: This struct is quite stubbed out.
{
    ino_t st_ino;
    mode_t st_mode;
    off_t st_size;
    int st_dev;   // FIXME: Implement this.
    int st_nlink; // FIXME: Implement this.
    uid_t st_uid;
    gid_t st_gid;
    time_t st_atime;
    time_t st_mtime;
    time_t st_ctime;
};

void do_stat(Context* context, VFS::Node* node, struct stat* buf)
{
    struct stat stat;
    stat.st_ino = node->inode;
    stat.st_mode = node->mode | ((1 << (node->type)) * 010000);
    stat.st_size = node->length;
    stat.st_uid = node->uid;
    stat.st_gid = node->gid;
    stat.st_atime = node->atime;
    stat.st_ctime = node->ctime;
    stat.st_mtime = node->mtime;
    stat.st_dev = 0;
    stat.st_nlink = 0;
    if (!copy_typed_to_user(buf, &stat)) context->rax = -EFAULT;
    else
        context->rax = 0;
}

void sys_fstat(Context* context, int fd, struct stat* buf)
{
    Task* current_task = Scheduler::current_task();
    if (fd < 0 || fd >= TASK_MAX_FDS)
    {
        context->rax = -EBADF;
        return;
    }
    Descriptor& file = current_task->files[fd];
    if (!file.is_open())
    {
        context->rax = -EBADF;
        return;
    }
    VFS::Node* node = file.node();
    return do_stat(context, node, buf);
}

void sys_stat(Context* context, const char* path, struct stat* buf)
{
    auto result = strdup_from_user(path);
    if (result.has_error())
    {
        context->rax = -result.error();
        return;
    }
    char* kpath = result.release_value();
    VFS::Node* node = VFS::resolve_path(kpath);
    kfree(kpath);
    if (!node)
    {
        context->rax = -ENOENT;
        return;
    }
    return do_stat(context, node, buf);
}