/*
 * tc_filter.c		"tc filter".
 *
 *		This program is free software; you can redistribute 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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 */

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

#include "rt_names.h"
#include "utils.h"
#include "tc_util.h"
#include "tc_common.h"

static void usage(void)
{
	fprintf(stderr,
		"Usage: tc filter [ add | del | change | replace | show ] dev STRING\n"
		"Usage: tc filter get dev STRING parent CLASSID protocol PROTO handle FILTERID pref PRIO FILTER_TYPE\n"
		"       [ pref PRIO ] protocol PROTO [ chain CHAIN_INDEX ]\n"
		"       [ estimator INTERVAL TIME_CONSTANT ]\n"
		"       [ root | ingress | egress | parent CLASSID ]\n"
		"       [ handle FILTERID ] [ [ FILTER_TYPE ] [ help | OPTIONS ] ]\n"
		"\n"
		"       tc filter show [ dev STRING ] [ root | ingress | egress | parent CLASSID ]\n"
		"Where:\n"
		"FILTER_TYPE := { rsvp | u32 | bpf | fw | route | etc. }\n"
		"FILTERID := ... format depends on classifier, see there\n"
		"OPTIONS := ... try tc filter add <desired FILTER_KIND> help\n");
}

static int tc_filter_modify(int cmd, unsigned int flags, int argc, char **argv)
{
	struct {
		struct nlmsghdr	n;
		struct tcmsg		t;
		char			buf[MAX_MSG];
	} req = {
		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
		.n.nlmsg_flags = NLM_F_REQUEST | flags,
		.n.nlmsg_type = cmd,
		.t.tcm_family = AF_UNSPEC,
	};
	struct filter_util *q = NULL;
	__u32 prio = 0;
	__u32 protocol = 0;
	int protocol_set = 0;
	__u32 chain_index;
	int chain_index_set = 0;
	char *fhandle = NULL;
	char  d[16] = {};
	char  k[16] = {};
	struct tc_estimator est = {};

	if (cmd == RTM_NEWTFILTER && flags & NLM_F_CREATE)
		protocol = htons(ETH_P_ALL);

	while (argc > 0) {
		if (strcmp(*argv, "dev") == 0) {
			NEXT_ARG();
			if (d[0])
				duparg("dev", *argv);
			strncpy(d, *argv, sizeof(d)-1);
		} else if (strcmp(*argv, "root") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"root\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_ROOT;
		} else if (strcmp(*argv, "ingress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"ingress\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
						     TC_H_MIN_INGRESS);
		} else if (strcmp(*argv, "egress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"egress\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
						     TC_H_MIN_EGRESS);
		} else if (strcmp(*argv, "parent") == 0) {
			__u32 handle;

			NEXT_ARG();
			if (req.t.tcm_parent)
				duparg("parent", *argv);
			if (get_tc_classid(&handle, *argv))
				invarg("Invalid parent ID", *argv);
			req.t.tcm_parent = handle;
		} else if (strcmp(*argv, "handle") == 0) {
			NEXT_ARG();
			if (fhandle)
				duparg("handle", *argv);
			fhandle = *argv;
		} else if (matches(*argv, "preference") == 0 ||
			   matches(*argv, "priority") == 0) {
			NEXT_ARG();
			if (prio)
				duparg("priority", *argv);
			if (get_u32(&prio, *argv, 0) || prio > 0xFFFF)
				invarg("invalid priority value", *argv);
		} else if (matches(*argv, "protocol") == 0) {
			__u16 id;

			NEXT_ARG();
			if (protocol_set)
				duparg("protocol", *argv);
			if (ll_proto_a2n(&id, *argv))
				invarg("invalid protocol", *argv);
			protocol = id;
			protocol_set = 1;
		} else if (matches(*argv, "chain") == 0) {
			NEXT_ARG();
			if (chain_index_set)
				duparg("chain", *argv);
			if (get_u32(&chain_index, *argv, 0))
				invarg("invalid chain index value", *argv);
			chain_index_set = 1;
		} else if (matches(*argv, "estimator") == 0) {
			if (parse_estimator(&argc, &argv, &est) < 0)
				return -1;
		} else if (matches(*argv, "help") == 0) {
			usage();
			return 0;
		} else {
			strncpy(k, *argv, sizeof(k)-1);

			q = get_filter_kind(k);
			argc--; argv++;
			break;
		}

		argc--; argv++;
	}

	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);

	if (chain_index_set)
		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);

	if (k[0])
		addattr_l(&req.n, sizeof(req), TCA_KIND, k, strlen(k)+1);

	if (q) {
		if (q->parse_fopt(q, fhandle, argc, argv, &req.n))
			return 1;
	} else {
		if (fhandle) {
			fprintf(stderr,
				"Must specify filter type when using \"handle\"\n");
			return -1;
		}
		if (argc) {
			if (matches(*argv, "help") == 0)
				usage();
			fprintf(stderr,
				"Garbage instead of arguments \"%s ...\". Try \"tc filter help\".\n",
				*argv);
			return -1;
		}
	}

	if (est.ewma_log)
		addattr_l(&req.n, sizeof(req), TCA_RATE, &est, sizeof(est));


	if (d[0])  {
		ll_init_map(&rth);

		req.t.tcm_ifindex = ll_name_to_index(d);
		if (req.t.tcm_ifindex == 0) {
			fprintf(stderr, "Cannot find device \"%s\"\n", d);
			return 1;
		}
	}

	if (rtnl_talk(&rth, &req.n, NULL, 0) < 0) {
		fprintf(stderr, "We have an error talking to the kernel\n");
		return 2;
	}

	return 0;
}

static __u32 filter_parent;
static int filter_ifindex;
static __u32 filter_prio;
static __u32 filter_protocol;
static __u32 filter_chain_index;
static int filter_chain_index_set;
__u16 f_proto;

int print_filter(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
	FILE *fp = (FILE *)arg;
	struct tcmsg *t = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	struct rtattr *tb[TCA_MAX+1];
	struct filter_util *q;
	char abuf[256];

	if (n->nlmsg_type != RTM_NEWTFILTER &&
	    n->nlmsg_type != RTM_GETTFILTER &&
	    n->nlmsg_type != RTM_DELTFILTER) {
		fprintf(stderr, "Not a filter(cmd %d)\n", n->nlmsg_type);
		return 0;
	}
	len -= NLMSG_LENGTH(sizeof(*t));
	if (len < 0) {
		fprintf(stderr, "Wrong len %d\n", len);
		return -1;
	}

	parse_rtattr(tb, TCA_MAX, TCA_RTA(t), len);

	if (tb[TCA_KIND] == NULL) {
		fprintf(stderr, "print_filter: NULL kind\n");
		return -1;
	}

	if (n->nlmsg_type == RTM_DELTFILTER)
		fprintf(fp, "deleted ");

	if (n->nlmsg_type == RTM_NEWTFILTER &&
			(n->nlmsg_flags & NLM_F_CREATE) &&
			!(n->nlmsg_flags & NLM_F_EXCL))
		fprintf(fp, "replaced ");

	if (n->nlmsg_type == RTM_NEWTFILTER &&
			(n->nlmsg_flags & NLM_F_CREATE) &&
			(n->nlmsg_flags & NLM_F_EXCL))
		fprintf(fp, "added ");

	fprintf(fp, "filter ");
	if (!filter_ifindex || filter_ifindex != t->tcm_ifindex)
		fprintf(fp, "dev %s ", ll_index_to_name(t->tcm_ifindex));

	if (!filter_parent || filter_parent != t->tcm_parent) {
		if (t->tcm_parent == TC_H_ROOT)
			fprintf(fp, "root ");
		else if (t->tcm_parent == TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS))
			fprintf(fp, "ingress ");
		else if (t->tcm_parent == TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS))
			fprintf(fp, "egress ");
		else {
			print_tc_classid(abuf, sizeof(abuf), t->tcm_parent);
			fprintf(fp, "parent %s ", abuf);
		}
	}

	if (t->tcm_info) {
		f_proto = TC_H_MIN(t->tcm_info);
		__u32 prio = TC_H_MAJ(t->tcm_info)>>16;

		if (!filter_protocol || filter_protocol != f_proto) {
			if (f_proto) {
				SPRINT_BUF(b1);
				fprintf(fp, "protocol %s ",
					ll_proto_n2a(f_proto, b1, sizeof(b1)));
			}
		}
		if (!filter_prio || filter_prio != prio) {
			if (prio)
				fprintf(fp, "pref %u ", prio);
		}
	}
	fprintf(fp, "%s ", rta_getattr_str(tb[TCA_KIND]));

	if (tb[TCA_CHAIN]) {
		__u32 chain_index = rta_getattr_u32(tb[TCA_CHAIN]);

		if (!filter_chain_index_set ||
		    filter_chain_index != chain_index)
			fprintf(fp, "chain %u ", chain_index);
	}

	q = get_filter_kind(RTA_DATA(tb[TCA_KIND]));
	if (tb[TCA_OPTIONS]) {
		if (q)
			q->print_fopt(q, fp, tb[TCA_OPTIONS], t->tcm_handle);
		else
			fprintf(fp, "[cannot parse parameters]");
	}
	fprintf(fp, "\n");

	if (show_stats && (tb[TCA_STATS] || tb[TCA_STATS2])) {
		print_tcstats_attr(fp, tb, " ", NULL);
		fprintf(fp, "\n");
	}

	fflush(fp);
	return 0;
}

static int tc_filter_get(int cmd, unsigned int flags, int argc, char **argv)
{
	struct {
		struct nlmsghdr	n;
		struct tcmsg		t;
		char			buf[MAX_MSG];
	} req = {
		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
		/* NLM_F_ECHO is for backward compatibility. old kernels never
		 * respond without it and newer kernels will ignore it.
		 * In old kernels there is a side effect:
		 * In addition to a response to the GET you will receive an
		 * event (if you do tc mon).
		 */
		.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ECHO | flags,
		.n.nlmsg_type = cmd,
		.t.tcm_parent = TC_H_UNSPEC,
		.t.tcm_family = AF_UNSPEC,
	};
	struct filter_util *q = NULL;
	__u32 prio = 0;
	__u32 protocol = 0;
	int protocol_set = 0;
	__u32 chain_index;
	int chain_index_set = 0;
	__u32 parent_handle = 0;
	char *fhandle = NULL;
	char  d[16] = {};
	char  k[16] = {};

	while (argc > 0) {
		if (strcmp(*argv, "dev") == 0) {
			NEXT_ARG();
			if (d[0])
				duparg("dev", *argv);
			strncpy(d, *argv, sizeof(d)-1);
		} else if (strcmp(*argv, "root") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"root\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_ROOT;
		} else if (strcmp(*argv, "ingress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"ingress\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
						     TC_H_MIN_INGRESS);
		} else if (strcmp(*argv, "egress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"egress\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
						     TC_H_MIN_EGRESS);
		} else if (strcmp(*argv, "parent") == 0) {

			NEXT_ARG();
			if (req.t.tcm_parent)
				duparg("parent", *argv);
			if (get_tc_classid(&parent_handle, *argv))
				invarg("Invalid parent ID", *argv);
			req.t.tcm_parent = parent_handle;
		} else if (strcmp(*argv, "handle") == 0) {
			NEXT_ARG();
			if (fhandle)
				duparg("handle", *argv);
			fhandle = *argv;
		} else if (matches(*argv, "preference") == 0 ||
			   matches(*argv, "priority") == 0) {
			NEXT_ARG();
			if (prio)
				duparg("priority", *argv);
			if (get_u32(&prio, *argv, 0) || prio > 0xFFFF)
				invarg("invalid priority value", *argv);
		} else if (matches(*argv, "protocol") == 0) {
			__u16 id;

			NEXT_ARG();
			if (protocol_set)
				duparg("protocol", *argv);
			if (ll_proto_a2n(&id, *argv))
				invarg("invalid protocol", *argv);
			protocol = id;
			protocol_set = 1;
		} else if (matches(*argv, "chain") == 0) {
			NEXT_ARG();
			if (chain_index_set)
				duparg("chain", *argv);
			if (get_u32(&chain_index, *argv, 0))
				invarg("invalid chain index value", *argv);
			chain_index_set = 1;
		} else if (matches(*argv, "help") == 0) {
			usage();
			return 0;
		} else {
			if (!**argv)
				invarg("invalid filter name", *argv);

			strncpy(k, *argv, sizeof(k)-1);

			q = get_filter_kind(k);
			argc--; argv++;
			break;
		}

		argc--; argv++;
	}

	if (!protocol_set) {
		fprintf(stderr, "Must specify filter protocol\n");
		return -1;
	}

	if (!prio) {
		fprintf(stderr, "Must specify filter priority\n");
		return -1;
	}

	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);

	if (chain_index_set)
		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);

	if (req.t.tcm_parent == TC_H_UNSPEC) {
		fprintf(stderr, "Must specify filter parent\n");
		return -1;
	}

	if (k[0])
		addattr_l(&req.n, sizeof(req), TCA_KIND, k, strlen(k)+1);
	else {
		fprintf(stderr, "Must specify filter type\n");
		return -1;
	}

	if (q->parse_fopt(q, fhandle, argc, argv, &req.n))
		return 1;


	if (!fhandle) {
		fprintf(stderr, "Must specify filter \"handle\"\n");
		return -1;
	}

	if (argc) {
		if (matches(*argv, "help") == 0)
			usage();
		fprintf(stderr,
			"Garbage instead of arguments \"%s ...\". Try \"tc filter help\".\n",
			*argv);
		return -1;
	}

	if (d[0])  {
		ll_init_map(&rth);

		req.t.tcm_ifindex = ll_name_to_index(d);
		if (req.t.tcm_ifindex  == 0) {
			fprintf(stderr, "Cannot find device \"%s\"\n", d);
			return 1;
		}
		filter_ifindex = req.t.tcm_ifindex;
	} else {
		fprintf(stderr, "Must specify netdevice \"dev\"\n");
		return -1;
	}

	if (rtnl_talk(&rth, &req.n, &req.n, MAX_MSG) < 0) {
		fprintf(stderr, "We have an error talking to the kernel\n");
		return 2;
	}

	print_filter(NULL, &req.n, (void *)stdout);

	return 0;
}

static int tc_filter_list(int argc, char **argv)
{
	struct {
		struct nlmsghdr n;
		struct tcmsg t;
		char buf[MAX_MSG];
	} req = {
		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
		.n.nlmsg_type = RTM_GETTFILTER,
		.t.tcm_parent = TC_H_UNSPEC,
		.t.tcm_family = AF_UNSPEC,
	};
	char d[16] = {};
	__u32 prio = 0;
	__u32 protocol = 0;
	__u32 chain_index;
	char *fhandle = NULL;

	while (argc > 0) {
		if (strcmp(*argv, "dev") == 0) {
			NEXT_ARG();
			if (d[0])
				duparg("dev", *argv);
			strncpy(d, *argv, sizeof(d)-1);
		} else if (strcmp(*argv, "root") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"root\" is duplicate parent ID\n");
				return -1;
			}
			filter_parent = req.t.tcm_parent = TC_H_ROOT;
		} else if (strcmp(*argv, "ingress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"ingress\" is duplicate parent ID\n");
				return -1;
			}
			filter_parent = TC_H_MAKE(TC_H_CLSACT,
						  TC_H_MIN_INGRESS);
			req.t.tcm_parent = filter_parent;
		} else if (strcmp(*argv, "egress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr,
					"Error: \"egress\" is duplicate parent ID\n");
				return -1;
			}
			filter_parent = TC_H_MAKE(TC_H_CLSACT,
						  TC_H_MIN_EGRESS);
			req.t.tcm_parent = filter_parent;
		} else if (strcmp(*argv, "parent") == 0) {
			__u32 handle;

			NEXT_ARG();
			if (req.t.tcm_parent)
				duparg("parent", *argv);
			if (get_tc_classid(&handle, *argv))
				invarg("invalid parent ID", *argv);
			filter_parent = req.t.tcm_parent = handle;
		} else if (strcmp(*argv, "handle") == 0) {
			NEXT_ARG();
			if (fhandle)
				duparg("handle", *argv);
			fhandle = *argv;
		} else if (matches(*argv, "preference") == 0 ||
			   matches(*argv, "priority") == 0) {
			NEXT_ARG();
			if (prio)
				duparg("priority", *argv);
			if (get_u32(&prio, *argv, 0))
				invarg("invalid preference", *argv);
			filter_prio = prio;
		} else if (matches(*argv, "protocol") == 0) {
			__u16 res;

			NEXT_ARG();
			if (protocol)
				duparg("protocol", *argv);
			if (ll_proto_a2n(&res, *argv))
				invarg("invalid protocol", *argv);
			protocol = res;
			filter_protocol = protocol;
		} else if (matches(*argv, "chain") == 0) {
			NEXT_ARG();
			if (filter_chain_index_set)
				duparg("chain", *argv);
			if (get_u32(&chain_index, *argv, 0))
				invarg("invalid chain index value", *argv);
			filter_chain_index_set = 1;
			filter_chain_index = chain_index;
		} else if (matches(*argv, "help") == 0) {
			usage();
		} else {
			fprintf(stderr,
				" What is \"%s\"? Try \"tc filter help\"\n",
				*argv);
			return -1;
		}

		argc--; argv++;
	}

	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);

	ll_init_map(&rth);

	if (d[0]) {
		req.t.tcm_ifindex = ll_name_to_index(d);
		if (req.t.tcm_ifindex == 0) {
			fprintf(stderr, "Cannot find device \"%s\"\n", d);
			return 1;
		}
		filter_ifindex = req.t.tcm_ifindex;
	}

	if (filter_chain_index_set)
		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);

	if (rtnl_dump_request_n(&rth, &req.n) < 0) {
		perror("Cannot send dump request");
		return 1;
	}

	if (rtnl_dump_filter(&rth, print_filter, stdout) < 0) {
		fprintf(stderr, "Dump terminated\n");
		return 1;
	}

	return 0;
}

int do_filter(int argc, char **argv)
{
	if (argc < 1)
		return tc_filter_list(0, NULL);
	if (matches(*argv, "add") == 0)
		return tc_filter_modify(RTM_NEWTFILTER, NLM_F_EXCL|NLM_F_CREATE,
					argc-1, argv+1);
	if (matches(*argv, "change") == 0)
		return tc_filter_modify(RTM_NEWTFILTER, 0, argc-1, argv+1);
	if (matches(*argv, "replace") == 0)
		return tc_filter_modify(RTM_NEWTFILTER, NLM_F_CREATE, argc-1,
					argv+1);
	if (matches(*argv, "delete") == 0)
		return tc_filter_modify(RTM_DELTFILTER, 0,  argc-1, argv+1);
	if (matches(*argv, "get") == 0)
		return tc_filter_get(RTM_GETTFILTER, 0,  argc-1, argv+1);
	if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
	    || matches(*argv, "lst") == 0)
		return tc_filter_list(argc-1, argv+1);
	if (matches(*argv, "help") == 0) {
		usage();
		return 0;
	}
	fprintf(stderr, "Command \"%s\" is unknown, try \"tc filter help\".\n",
		*argv);
	return -1;
}