Pawnyable LK04

fuse_example.c

// gcc fuse.c -o test -D_FILE_OFFSET_BITS=64 -static -pthread -lfuse -ldl
#define FUSE_USE_VERSION 29
#include <errno.h>
#include <fuse.h>
#include <stdio.h>
#include <string.h>

void fatal(const char *msg) {
    perror(msg);
    exit(1);
}

static const char *content = "Hello, World!\n";

static int getattr_callback(const char *path, struct stat *stbuf) {
    puts("[+] getattr_callback");
    memset(stbuf, 0, sizeof(struct stat));

    if (strcmp(path, "/file") == 0) {
        stbuf->st_mode = S_IFREG | 0777;
        stbuf->st_nlink = 1;
        stbuf->st_size = strlen(content);
        return 0;
    }
    return -ENOENT;
}

static int open_callback(const char *path, struct fuse_file_info *fi) {
    puts("[+] open_callback");
    return 0;
}

static int read_callback(const char *path,
                         char *buf, size_t size, off_t offset,
                         struct fuse_file_info *fi) {
    puts("[+] read_callback");

    if (strcmp(path, "/file") == 0) {
        size_t len = strlen(content);
        if (offset >= len)
            return 0;

        if ((size > len) || (offset + size > len)) {
            memcpy(buf, content + offset, len - offset);
            return len - offset;
        } else {
            memcpy(buf, content + offset, size);
            return size;
        }
    }

    return -ENOENT;
}

static struct fuse_operations fops = {
    .getattr = getattr_callback,
    .open = open_callback,
    .read = read_callback,
};

/*
int main(int argc, char *argv[]) {
  return fuse_main(argc, argv, &fops, NULL);
}
*/
int main() {
    struct fuse_args args = FUSE_ARGS_INIT(0, NULL);
    struct fuse_chan *chan;
    struct fuse *fuse;

    if (!(chan = fuse_mount("/tmp/test", &args)))
        fatal("fuse_mount");

    if (!(fuse = fuse_new(chan, &args, &fops, sizeof(fops), NULL))) {
        fuse_unmount("/tmp/test", chan);
        fatal("fuse_new");
    }

    fuse_set_signal_handlers(fuse_get_session(fuse));
    fuse_loop_mt(fuse);

    fuse_unmount("/tmp/test", chan);

    return 0;
}