#include <sys/capsicum.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <err.h>
#include <sys/ioccom.h>
#include <net/bpf.h>

int main(void)
{
    u_int mode;
    if (-1 == cap_getmode(&mode)) {
        perror("cap_getmode() failed:");
        exit(1);
    } else {
        assert(mode == 0U);
    }

    // example from man cap_rights_get
    cap_rights_t setrights, getrights;
    int fd;

    memset(&setrights, 0, sizeof(setrights));
    memset(&getrights, 0, sizeof(getrights));

    fd = open("capsicum.c", O_RDONLY);
    if (fd < 0)
        err(1, "open() failed");

    cap_rights_init(&setrights, CAP_IOCTL, CAP_FSTAT, CAP_READ);
    if (cap_rights_limit(fd, &setrights) < 0 && errno != ENOSYS)
        err(1, "cap_rights_limit() failed");

    unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };    
    if (cap_ioctls_limit(fd, cmds, sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
        err(1, "cap_ioctls_limit() filed");
    }

    uint32_t fcntlrights = CAP_FCNTL_GETFL | CAP_FCNTL_SETFL;
    if (cap_fcntls_limit(STDIN_FILENO, fcntlrights) < 0 && errno != ENOSYS) {
        err(1, "cap_fcnls_limit() filed");
    }

    if (cap_rights_get(fd, &getrights) < 0 && errno != ENOSYS)
        err(1, "cap_rights_get() failed");

    assert(memcmp(&setrights, &getrights, sizeof(setrights)) == 0);
 
    unsigned long getcmds[2];
    if (cap_ioctls_get(fd, getcmds, 2) < 0 && errno != ENOSYS)
        err(1, "cap_ioctls_get() failed");
 
    assert(memcmp(cmds, getcmds, sizeof(cmds)) == 0);
 
    uint32_t getfcntlrights;
    if (cap_fcntls_get(STDIN_FILENO, &getfcntlrights) < 0 && errno != ENOSYS) {
        err(1, "cap_fcnls_limit() filed");
    }
 
    assert(fcntlrights == getfcntlrights);
 
    //close(fd);

    cap_enter();
 
    if (-1 == cap_getmode(&mode)) {
        perror("cap_getmode() failed:");
        exit(1);
    } else {
        assert(mode != 0U);
    }

    // error section

    int *px = malloc(sizeof(int));
    int x = px[0];
 
    cap_getmode(NULL);

    cap_rights_get(0, NULL);
    cap_rights_get(x, &getrights);
    cap_rights_t* badrights = malloc(sizeof(cap_rights_t));
    cap_rights_init(badrights, CAP_FSTAT, CAP_READ);
    free(badrights);
    cap_rights_get(0, badrights);
 
    cap_rights_limit(x, &setrights);
 
    cap_rights_limit(fd, badrights);

    int fd2 = open("foo", O_RDWR);
    if (fd2 >= 0)
        err(1, "open in write mode should have failed");
}