tc/f_basic.c

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * f_basic.c		Basic Classifier
 *
 * Authors:	Thomas Graf <tgraf@suug.ch>
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <linux/if.h>

#include "utils.h"
#include "tc_util.h"
#include "m_ematch.h"

static void explain(void)
{
	fprintf(stderr,
		"Usage: ... basic [ match EMATCH_TREE ]\n"
		"                 [ action ACTION_SPEC ] [ classid CLASSID ]\n"
		"\n"
		"Where:	SELECTOR := SAMPLE SAMPLE ...\n"
		"	FILTERID := X:Y:Z\n"
		"	ACTION_SPEC := ... look at individual actions\n"
		"\n"
		"NOTE: CLASSID is parsed as hexadecimal input.\n");
}

static int basic_parse_opt(const struct filter_util *qu, char *handle,
			   int argc, char **argv, struct nlmsghdr *n)
{
	struct tcmsg *t = NLMSG_DATA(n);
	struct rtattr *tail;
	long h = 0;

	if (handle) {
		h = strtol(handle, NULL, 0);
		if (h == LONG_MIN || h == LONG_MAX) {
			fprintf(stderr, "Illegal handle \"%s\", must be numeric.\n",
			    handle);
			return -1;
		}
	}
	t->tcm_handle = h;

	if (argc == 0)
		return 0;

	tail = (struct rtattr *)(((void *)n)+NLMSG_ALIGN(n->nlmsg_len));
	addattr_l(n, MAX_MSG, TCA_OPTIONS, NULL, 0);

	while (argc > 0) {
		if (matches(*argv, "match") == 0) {
			NEXT_ARG();
			if (parse_ematch(&argc, &argv, TCA_BASIC_EMATCHES, n)) {
				fprintf(stderr, "Illegal \"ematch\"\n");
				return -1;
			}
			continue;
		} else if (matches(*argv, "classid") == 0 ||
			   strcmp(*argv, "flowid") == 0) {
			unsigned int classid;

			NEXT_ARG();
			if (get_tc_classid(&classid, *argv)) {
				fprintf(stderr, "Illegal \"classid\"\n");
				return -1;
			}
			addattr_l(n, MAX_MSG, TCA_BASIC_CLASSID, &classid, 4);
		} else if (matches(*argv, "action") == 0) {
			NEXT_ARG();
			if (parse_action(&argc, &argv, TCA_BASIC_ACT, n)) {
				fprintf(stderr, "Illegal \"action\"\n");
				return -1;
			}
			continue;

		} else if (matches(*argv, "police") == 0) {
			NEXT_ARG();
			if (parse_police(&argc, &argv, TCA_BASIC_POLICE, n)) {
				fprintf(stderr, "Illegal \"police\"\n");
				return -1;
			}
			continue;
		} else if (strcmp(*argv, "help") == 0) {
			explain();
			return -1;
		} else {
			fprintf(stderr, "What is \"%s\"?\n", *argv);
			explain();
			return -1;
		}
		argc--; argv++;
	}

	tail->rta_len = (((void *)n)+n->nlmsg_len) - (void *)tail;
	return 0;
}

static int basic_print_opt(const struct filter_util *qu, FILE *f,
			   struct rtattr *opt, __u32 handle)
{
	struct rtattr *tb[TCA_BASIC_MAX+1];

	if (opt == NULL)
		return 0;

	parse_rtattr_nested(tb, TCA_BASIC_MAX, opt);

	if (handle)
		print_hex(PRINT_ANY, "handle",
			  "handle 0x%x ", handle);

	if (tb[TCA_BASIC_CLASSID]) {
		uint32_t classid = rta_getattr_u32(tb[TCA_BASIC_CLASSID]);
		SPRINT_BUF(b1);

		print_string(PRINT_ANY, "flowid", "flowid %s ",
			     sprint_tc_classid(classid, b1));
	}

	if (tb[TCA_BASIC_EMATCHES])
		print_ematch(f, tb[TCA_BASIC_EMATCHES]);

	if (tb[TCA_BASIC_POLICE]) {
		print_nl();
		tc_print_police(tb[TCA_BASIC_POLICE]);
	}

	if (tb[TCA_BASIC_ACT]) {
		tc_print_action(f, tb[TCA_BASIC_ACT], 0);
	}

	return 0;
}

struct filter_util basic_filter_util = {
	.id = "basic",
	.parse_fopt = basic_parse_opt,
	.print_fopt = basic_print_opt,
};