file_descriptors.c

//
// Created by maractus on 03.01.24.
//
 
// NOTE: They needed for userspace apps!
 
#include "sys/file_descriptors.h"
#include "../src/lib/libvector/include/vector.h"
#include "mem/vmm.h"
#include "io/ports.h"
 
vector_t* descriptors = 0;
int last_descriptor_number = 0;
 
void file_descriptors_init() {
    descriptors = vector_new();
 
    qemu_log("File descriptors initialized");
}
 
// WARNING: Part of system calls! So every func needs to return size_t
size_t file_descriptor_allocate(const char *filename, size_t mode, int *out) {
    FILE* file = fopen_binmode(filename, mode);
 
    if(!file) {
        *out = -1;
        return 0;
    }
 
    struct fd_info* inf = kcalloc(sizeof *inf, 1);
 
    inf->fd = last_descriptor_number++;
    inf->file = file;
 
    vector_push_back(descriptors, (size_t) inf);
 
    *out = inf->fd;
 
    qemu_ok("Written to: %d", out);
    qemu_log("allocated fd: %d", inf->fd);
 
    return 0;
}
 
struct fd_info* file_descriptor_get(int descriptor_number) {
    for(int i = 0; i < descriptors->size; i++) {
        struct fd_info *inf = (struct fd_info *) vector_get(descriptors, i).element;
 
        if (inf->fd == descriptor_number) {
            return inf;
        }
    }
 
    return NULL;
}
 
size_t file_descriptor_read(int descriptor_number, size_t count, void* buffer) {
    qemu_log("FD: %d; Size: %d; Buffer: %x", descriptor_number, count, buffer);
 
    if(descriptor_number < 0 || descriptor_number >= last_descriptor_number) {
        qemu_err("Invalid descriptor: %d!", descriptor_number);
        return 0;
    }
 
    if(!file_descriptor_get(descriptor_number)) {
        return 0;
    }
 
    struct fd_info* inf = file_descriptor_get(descriptor_number);
 
    qemu_note("[%x] Read: %d bytes (buffer at: %x)", inf, count, buffer);
 
    fread(inf->file, count, 1, buffer);
    
    qemu_note("Read finished!");
 
    qemu_log("%s\n", buffer);
 
    return 0;
}
 
size_t file_descriptor_write(int descriptor_number, size_t count, const void* buffer) {
    qemu_log("FD: %d; Size: %d; Buffer: %x", descriptor_number, count, buffer);
 
    if(descriptor_number < 0 || descriptor_number >= last_descriptor_number) {
        qemu_err("Invalid descriptor: %d!", descriptor_number);
        return 0;
    }
 
    if(!file_descriptor_get(descriptor_number)) {
            return 0;
        }
 
    struct fd_info* inf = file_descriptor_get(descriptor_number);
 
    qemu_note("[%x] Write: %d bytes (buffer at: %x)", inf, count, buffer);
 
    fwrite(inf->file, count, 1, buffer);
 
    return 0;
}
 
size_t file_descriptor_close(int descriptor_number) {
    if(descriptor_number < 0 || descriptor_number >= last_descriptor_number)
        return 0;
 
    for(int i = 0; i < descriptors->size; i++) {
        struct fd_info *inf = (struct fd_info *) vector_get(descriptors, i).element;
 
        if (inf->fd == descriptor_number) {
            fclose(inf->file);
 
            vector_erase_nth(descriptors, i);
 
            kfree(inf);
 
            qemu_ok("Destroyed: %d", descriptor_number);
 
            return 0;
        }
    }
 
    qemu_err("FAILED TO DESTROY fd: %d", descriptor_number);
 
    return 0;
}
 
size_t file_descriptor_seek(int descriptor_number, ssize_t value, size_t whence) {
    /*if(descriptor_number < 0 || descriptor_number >= last_descriptor_number)
        return;
 
    for(int i = 0; i < descriptors->size; i++) {
        struct fd_info *inf = (struct fd_info *) vector_get(descriptors, i).element;
 
        if (inf->fd == descriptor_number) {
            fseek(inf->file, value, whence);
 
            return;
        }
    }*/
 
    if(descriptor_number < 0 || descriptor_number >= last_descriptor_number) {
        qemu_err("Invalid descriptor: %d!", descriptor_number);
        return 0;
    }
 
    if(!file_descriptor_get(descriptor_number)) {
            return 0;
        }
 
    struct fd_info* inf = file_descriptor_get(descriptor_number);
 
    qemu_note("[%x] Seek: Value: %x; Whence: %x", inf, value, whence);
 
    fseek(inf->file, value, whence);
 
    return 0;
 
}
 
size_t file_descriptor_tell(int descriptor_number, int* out) {
    if(descriptor_number < 0 || descriptor_number >= last_descriptor_number) {
        return 0;
    }
 
    if(!file_descriptor_get(descriptor_number)) {
            return 0;
        }
 
    struct fd_info* inf = file_descriptor_get(descriptor_number);
 
    *out = ftell(inf->file);
    
    return 0;
}