print libseccomp argument chains

print_chains.c

#include <stdarg.h>
#include <stdio.h>
static void print_line(int indent_level, const char *format, ...)
{
        int i;

        for (i = 0; i < indent_level; i++)
                fprintf(stdout, " ");

        va_list(args);
        va_start(args, format);
        vfprintf(stdout, format, args);
        va_end(args);
}

#define INDENT          2
static void print_chain(int indent_level, struct db_arg_chain_tree *chain)
{
        print_line(indent_level, "----chain---- %p\n", chain);
        print_line(indent_level + INDENT,
                   "arg = %d mask = 0x%x datum = 0x%x op = %d\n",
                   chain->arg, chain->mask, chain->datum, chain->op);
        print_line(indent_level + INDENT,
                   "act_t_flg = %d act_f_flg = %d\n",
                   chain->act_t_flg, chain->act_f_flg);
        print_line(indent_level + INDENT,
                   "act_t = 0x%08x act_f = 0x%08x\n",
                   chain->act_t, chain->act_f);
        print_line(indent_level + INDENT,
                   "lvl_prv = %p lvl nxt = %p\n",
                   chain->lvl_prv, chain->lvl_nxt);
        print_line(indent_level + INDENT,
                   "nxt_t = %p nxt_f = %p\n",
                   chain->nxt_t, chain->nxt_f);
}

static void print_chains(int indent_level,
                         const struct db_sys_list *sys,
                         struct db_arg_chain_tree *chain,
                         bool print_syscall_header)
{
        if (chain == NULL)
                return;

        if (print_syscall_header)
                print_line(indent_level, "----syscall %d----\n", sys->num);

        print_chain(indent_level + INDENT, chain);

        print_line(indent_level + 2 * INDENT, "----true chain----\n");
        print_chains(indent_level + 2 * INDENT, sys, chain->nxt_t, false);

        print_line(indent_level + 2 * INDENT, "----false chain----\n");
        print_chains(indent_level + 2 * INDENT, sys, chain->nxt_f, false);

        print_line(indent_level + 2 * INDENT, "----lvl nxt chain----\n");
        print_chains(indent_level + 2 * INDENT, sys, chain->lvl_nxt, false);
}


/* example usage */
for (i = 0; i < col->filter_cnt; i++) {
        syscall = col->filters[i]->syscalls;

        fprintf(stderr, "filter[%d]\n", i);
        while(syscall) {
                print_chains(0, syscall, syscall->chains, true);
                syscall = syscall->next;
        }
}