ZFS and Rust (d39cec65b025ad4c6de50e778ffd1177279b5b3d)

main.c

// Works as expected... if one gets it to compile

#include <libzfs.h>
#include <stdio.h>
#include <stdlib.h>

int zp_iter(zpool_handle_t *z, void *a) {
  printf("name:\t%s\n", zpool_get_name(z));
  return 0;
}

int main(void) {
  libzfs_handle_t *zh = libzfs_init();
  zpool_iter(zh, zp_iter, NULL);
  exit(0);
}

main.rs

use std::libc::{c_int, c_void, c_schar};

struct LibZFSHandle;
struct ZPoolHandle; /* {
    zpool_hdl: *mut c_void, // some pointers
    zpool_next: *mut c_void,
    zpool_name: [c_schar, ..256u], // The (known) content of this buffer is nowhere to be found
                                   // near the actual address of the first argument to `iter`.
    // more stuff
} */

#[link_args = "-lzfs"]
extern {
	// extern libzfs_handle_t *libzfs_init(void);
	fn libzfs_init() -> *mut LibZFSHandle;

	// typedef int (*zpool_iter_f)(zpool_handle_t *, void *);
	// extern int zpool_iter(libzfs_handle_t *, zpool_iter_f, void *);
	fn zpool_iter(a: *mut LibZFSHandle,
	              b: &fn(x: *mut ZPoolHandle,y: *mut c_void)-> c_int,
	              c: c_int)
	       -> c_int;

	// extern const char *zpool_get_name(zpool_handle_t *);
	fn zpool_get_name(arg1: *mut ZPoolHandle) -> *c_schar;
}

fn iter(h: *mut ZPoolHandle, v: *mut c_void) -> c_int {
	// This gets called for every available pool, like it is supposed to.
	// However `h` is always NULL.
	0
}

#[fixed_stack_segment]
fn main() {
	unsafe {
		let h = libzfs_init();
		zpool_iter(h, iter, 0);
	}
}