/*
 * Copyright (c) 2023 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * setcaps - Set capability restrictions on the parent process of this
 *           program (usually a shell).
 */
#include <sys/types.h>
#include <sys/caps.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

__SYSCAP_ALLSTRINGS;

static void printallcaps(void);
static void listcaps(void);

int
main(int ac, char **av)
{
        int quietopt = 0;
        int c;
        int i;
        int j;
        int estatus = 0;
        int noargs = 1;

        while ((c = getopt(ac, av, "plqh")) != -1) {
                noargs = 0;
                switch(c) {
                case 'p':
                        printallcaps();
                        break;
                case 'l':
                        listcaps();
                        break;
                case 'q':
                        quietopt = 1;
                        break;
                case 'h':
                default:
                        if (c != 'h')
                                fprintf(stderr, "Bad option: -%c\n", c);
                        fprintf(stderr, "setcaps [-p] [-l] caps...\n");
                        fprintf(stderr, "    -p - list available caps\n");
                        fprintf(stderr, "    -l - list current caps\n");
                        fprintf(stderr, "    -q - ignore unknown caps\n");
                        fprintf(stderr, "  caps[:es] - set specific flags\n");
                        fprintf(stderr, "  If no args, current caps are "
                                        "listed\n");
                        if (c != 'h')
                                exit(1);
                        exit(0);
                }
        }
        ac -= optind;
        av += optind;

        for (j = 0; j < ac; ++j) {
                char *which;
                char *scan;
                int res;
                int flags = __SYSCAP_SELF | __SYSCAP_EXEC;
                int found = 0;

                noargs = 0;

                which = av[j];
                if ((scan = strchr(which, ':')) != NULL) {
                        *scan++ = 0;
                        flags = 0;
                        while (*scan) {
                                switch (*scan) {
                                case 's':
                                        flags |= __SYSCAP_SELF;
                                        break;
                                case 'e':
                                        flags |= __SYSCAP_EXEC;
                                        break;
                                default:
                                        fprintf(stderr, "unknown flag %s:%c\n",
                                                which, *scan);
                                        break;
                                }
                                ++scan;
                        }
                }
                for (i = 0; i < __SYSCAP_COUNT; ++i) {
                        const char *ptr;

                        ptr = SyscapAllStrings[i / 16][i & 15];
                        if (ptr == NULL || strcmp(ptr, which) != 0)
                                continue;
                        found = 1;
                        res = syscap_set(i | __SYSCAP_INPARENT, flags, NULL, 0);
                        if (res < 0) {
                                fprintf(stderr, "%s: %s\n",
                                        which, strerror(errno));
                                estatus = 1;
                        } else {
                                printf("%s: ", which);
                                if (res & __SYSCAP_EXEC)
                                        printf(" on-exec");
                                if (res & __SYSCAP_SELF)
                                        printf(" on-self");
                                printf("\n");
                        }
                }
                if (found == 0 && quietopt == 0) {
                        printf("%s: not-found\n", which);
                }
        }
        if (noargs)
                listcaps();

        return estatus;
}

static void
printallcaps(void)
{
        const char *ptr;
        int i;

        for (i = 0; i < __SYSCAP_COUNT; ++i) {
                if ((ptr = SyscapAllStrings[i / 16][i & 15]) != NULL) {
                        printf("0x%04x %s\n", i, ptr);
                }
        }
}

static void
listcaps(void)
{
        int i;

        for (i = 0; i < __SYSCAP_COUNT; ++i) {
                const char *ptr;
                int res;

                res = syscap_get(i | __SYSCAP_INPARENT, NULL, 0);
                if (res < 0)
                        break;
                if (res) {
                        if ((ptr = SyscapAllStrings[i / 16][i & 15]) != NULL) {
                                printf("%-15s", ptr);
                        } else {
                                printf("0x%04x         ", res);
                        }
                        if (res & __SYSCAP_EXEC)
                                printf(" on-exec");
                        if (res & __SYSCAP_SELF)
                                printf(" on-self");
                        printf("\n");
                }
        }
}