#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include <seccomp.h>

#define seccomp_err(fun, ...)                                                  \
    do {                                                                       \
        int ret = fun(__VA_ARGS__);                                            \
        if (ret < 0) {                                                         \
            errno = -ret;                                                      \
            perror(#fun);                                                      \
            exit(1);                                                           \
        }                                                                      \
    } while (0)

int main() {
    scmp_filter_ctx ctx = seccomp_init(SCMP_ACT_ALLOW);

    if (ctx == NULL) {
        perror("seccomp_init");
        return 1;
    }

    seccomp_err(seccomp_rule_add, ctx, SCMP_ACT_KILL, SCMP_SYS(fork), 0);
    seccomp_err(seccomp_load, ctx);

    printf("And now we fork...\n");

    fork();
    printf("You should not see this because I'm dead.\n");

    return 0;
}