/*

 * f_bpf.c	BPF-based Classifier

 *

 *		This program is free software; you can distribute it and/or

 *		modify it under the terms of the GNU General Public License

 *		as published by the Free Software Foundation; either version

 *		2 of the License, or (at your option) any later version.

 *

 * Authors:	Daniel Borkmann <daniel@iogearbox.net>

 */

#include <stdio.h>

#include <stdlib.h>

#include <linux/bpf.h>

#include "utils.h"

#include "tc_util.h"

#include "bpf_util.h"

static const enum bpf_prog_type bpf_type = BPF_PROG_TYPE_SCHED_CLS;

static void explain(void)

{

	fprintf(stderr,

		"Usage: ... bpf ...\n"

		"\n"

		"BPF use case:\n"

		" bytecode BPF_BYTECODE\n"

		" bytecode-file FILE\n"

		"\n"

		"eBPF use case:\n"

		" object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]"

		" [ verbose ] [ direct-action ] [ skip_hw | skip_sw ]\n"

		" object-pinned FILE [ direct-action ] [ skip_hw | skip_sw ]\n"

		"\n"

		"Common remaining options:\n"

		" [ action ACTION_SPEC ]\n"

		" [ classid CLASSID ]\n"

		"\n"

		"Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n"

		"c,t,f,k and s are decimals; s denotes number of 4-tuples\n"

		"\n"

		"Where FILE points to a file containing the BPF_BYTECODE string,\n"

		"an ELF file containing eBPF map definitions and bytecode, or a\n"

		"pinned eBPF program.\n"

		"\n"

		"Where CLS_NAME refers to the section name containing the\n"

		"classifier (default \'%s\').\n"

		"\n"

		"Where UDS_FILE points to a unix domain socket file in order\n"

		"to hand off control of all created eBPF maps to an agent.\n"

		"\n"

		"ACTION_SPEC := ... look at individual actions\n"

		"NOTE: CLASSID is parsed as hexadecimal input.\n",

		bpf_prog_to_default_section(bpf_type));

}

static void bpf_cbpf_cb(void *nl, const struct sock_filter *ops, int ops_len)

{

	addattr16(nl, MAX_MSG, TCA_BPF_OPS_LEN, ops_len);

	addattr_l(nl, MAX_MSG, TCA_BPF_OPS, ops,

		  ops_len * sizeof(struct sock_filter));

}

static void bpf_ebpf_cb(void *nl, int fd, const char *annotation)

{

	addattr32(nl, MAX_MSG, TCA_BPF_FD, fd);

	addattrstrz(nl, MAX_MSG, TCA_BPF_NAME, annotation);

}

static const struct bpf_cfg_ops bpf_cb_ops = {

	.cbpf_cb = bpf_cbpf_cb,

	.ebpf_cb = bpf_ebpf_cb,

};

static int bpf_parse_opt(struct filter_util *qu, char *handle,

			 int argc, char **argv, struct nlmsghdr *n)

{

	const char *bpf_obj = NULL, *bpf_uds_name = NULL;

	struct tcmsg *t = NLMSG_DATA(n);

	unsigned int bpf_gen_flags = 0;

	unsigned int bpf_flags = 0;

	struct bpf_cfg_in cfg = {};

	bool seen_run = false;

	bool skip_sw = false;

	struct rtattr *tail;

	int ret = 0;

	if (handle) {

		if (get_u32(&t->tcm_handle, handle, 0)) {

			fprintf(stderr, "Illegal \"handle\"\n");

			return -1;

		}

	}

	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, "run") == 0) {

			NEXT_ARG();

			if (seen_run)

				duparg("run", *argv);

opt_bpf:

			seen_run = true;

			cfg.type = bpf_type;

			cfg.argc = argc;

			cfg.argv = argv;

			if (bpf_parse_common(&cfg, &bpf_cb_ops) < 0) {

				fprintf(stderr,

					"Unable to parse bpf command line\n");

				return -1;

			}

			argc = cfg.argc;

			argv = cfg.argv;

			bpf_obj = cfg.object;

			bpf_uds_name = cfg.uds;

		} else if (matches(*argv, "classid") == 0 ||

			   matches(*argv, "flowid") == 0) {

			unsigned int handle;

			NEXT_ARG();

			if (get_tc_classid(&handle, *argv)) {

				fprintf(stderr, "Illegal \"classid\"\n");

				return -1;

			}

			addattr32(n, MAX_MSG, TCA_BPF_CLASSID, handle);

		} else if (matches(*argv, "direct-action") == 0 ||

			   matches(*argv, "da") == 0) {

			bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;

		} else if (matches(*argv, "skip_hw") == 0) {

			bpf_gen_flags |= TCA_CLS_FLAGS_SKIP_HW;

		} else if (matches(*argv, "skip_sw") == 0) {

			bpf_gen_flags |= TCA_CLS_FLAGS_SKIP_SW;

			skip_sw = true;

		} else if (matches(*argv, "action") == 0) {

			NEXT_ARG();

			if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) {

				fprintf(stderr, "Illegal \"action\"\n");

				return -1;

			}

			continue;

		} else if (matches(*argv, "police") == 0) {

			NEXT_ARG();

			if (parse_police(&argc, &argv, TCA_BPF_POLICE, n)) {

				fprintf(stderr, "Illegal \"police\"\n");

				return -1;

			}

			continue;

		} else if (matches(*argv, "help") == 0) {

			explain();

			return -1;

		} else {

			if (!seen_run)

				goto opt_bpf;

			fprintf(stderr, "What is \"%s\"?\n", *argv);

			explain();

			return -1;

		}

		NEXT_ARG_FWD();

	}

	if (skip_sw)

		cfg.ifindex = t->tcm_ifindex;

	if (bpf_load_common(&cfg, &bpf_cb_ops, n) < 0) {

		fprintf(stderr, "Unable to load program\n");

		return -1;

	}

	if (bpf_gen_flags)

		addattr32(n, MAX_MSG, TCA_BPF_FLAGS_GEN, bpf_gen_flags);

	if (bpf_flags)

		addattr32(n, MAX_MSG, TCA_BPF_FLAGS, bpf_flags);

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

	if (bpf_uds_name)

		ret = bpf_send_map_fds(bpf_uds_name, bpf_obj);

	return ret;

}

static int bpf_print_opt(struct filter_util *qu, FILE *f,

			 struct rtattr *opt, __u32 handle)

{

	struct rtattr *tb[TCA_BPF_MAX + 1];

	int dump_ok = 0;

	if (opt == NULL)

		return 0;

	parse_rtattr_nested(tb, TCA_BPF_MAX, opt);

	if (handle)

		fprintf(f, "handle 0x%x ", handle);

	if (tb[TCA_BPF_CLASSID]) {

		SPRINT_BUF(b1);

		fprintf(f, "flowid %s ",

			sprint_tc_classid(rta_getattr_u32(tb[TCA_BPF_CLASSID]), b1));

	}

	if (tb[TCA_BPF_NAME])

		fprintf(f, "%s ", rta_getattr_str(tb[TCA_BPF_NAME]));

	if (tb[TCA_BPF_FLAGS]) {

		unsigned int flags = rta_getattr_u32(tb[TCA_BPF_FLAGS]);

		if (flags & TCA_BPF_FLAG_ACT_DIRECT)

			fprintf(f, "direct-action ");

	}

	if (tb[TCA_BPF_FLAGS_GEN]) {

		unsigned int flags =

			rta_getattr_u32(tb[TCA_BPF_FLAGS_GEN]);

		if (flags & TCA_CLS_FLAGS_SKIP_HW)

			fprintf(f, "skip_hw ");

		if (flags & TCA_CLS_FLAGS_SKIP_SW)

			fprintf(f, "skip_sw ");

		if (flags & TCA_CLS_FLAGS_IN_HW)

			fprintf(f, "in_hw ");

		else if (flags & TCA_CLS_FLAGS_NOT_IN_HW)

			fprintf(f, "not_in_hw ");

	}

	if (tb[TCA_BPF_OPS] && tb[TCA_BPF_OPS_LEN])

		bpf_print_ops(tb[TCA_BPF_OPS],

			      rta_getattr_u16(tb[TCA_BPF_OPS_LEN]));

	if (tb[TCA_BPF_ID])

		dump_ok = bpf_dump_prog_info(f, rta_getattr_u32(tb[TCA_BPF_ID]));

	if (!dump_ok && tb[TCA_BPF_TAG]) {

		SPRINT_BUF(b);

		fprintf(f, "tag %s ",

			hexstring_n2a(RTA_DATA(tb[TCA_BPF_TAG]),

				      RTA_PAYLOAD(tb[TCA_BPF_TAG]),

				      b, sizeof(b)));

	}

	if (tb[TCA_BPF_POLICE]) {

		fprintf(f, "\n");

		tc_print_police(f, tb[TCA_BPF_POLICE]);

	}

	if (tb[TCA_BPF_ACT])

		tc_print_action(f, tb[TCA_BPF_ACT], 0);

	return 0;

}

struct filter_util bpf_filter_util = {

	.id		= "bpf",

	.parse_fopt	= bpf_parse_opt,

	.print_fopt	= bpf_print_opt,

};