/*

 * q_gred.c		GRED.

 *

 *		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:    J Hadi Salim(hadi@nortelnetworks.com)

 *             code ruthlessly ripped from

 *	       Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>

 *

 */

#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 <math.h>

#include "utils.h"

#include "tc_util.h"

#include "tc_red.h"

#if 0

#define DPRINTF(format, args...) fprintf(stderr, format, ##args)

#else

#define DPRINTF(format, args...)

#endif

static void explain(void)

{

	fprintf(stderr,

		"Usage: tc qdisc { add | replace | change } ... gred setup vqs NUMBER\n"

		"           default DEFAULT_VQ [ grio ] [ limit BYTES ] [ecn] [harddrop]\n"

		"       tc qdisc change ... gred vq VQ [ prio VALUE ] limit BYTES\n"

		"           min BYTES max BYTES avpkt BYTES [ burst PACKETS ]\n"

		"           [ probability PROBABILITY ] [ bandwidth KBPS ] [ecn] [harddrop]\n");

}

static int init_gred(struct qdisc_util *qu, int argc, char **argv,

		     struct nlmsghdr *n)

{

	struct rtattr *tail;

	struct tc_gred_sopt opt = { 0 };

	__u32 limit = 0;

	opt.def_DP = MAX_DPs;

	while (argc > 0) {

		DPRINTF(stderr, "init_gred: invoked with %s\n", *argv);

		if (strcmp(*argv, "vqs") == 0 ||

		    strcmp(*argv, "DPs") == 0) {

			NEXT_ARG();

			if (get_unsigned(&opt.DPs, *argv, 10)) {

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

				return -1;

			} else if (opt.DPs > MAX_DPs) {

				fprintf(stderr, "GRED: only %u VQs are currently supported\n",

					MAX_DPs);

				return -1;

			}

		} else if (strcmp(*argv, "default") == 0) {

			if (opt.DPs == 0) {

				fprintf(stderr, "\"default\" must be defined after \"vqs\"\n");

				return -1;

			}

			NEXT_ARG();

			if (get_unsigned(&opt.def_DP, *argv, 10)) {

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

				return -1;

			} else if (opt.def_DP >= opt.DPs) {

				fprintf(stderr, "\"default\" must be less than \"vqs\"\n");

				return -1;

			}

		} else if (strcmp(*argv, "grio") == 0) {

			opt.grio = 1;

		} else if (strcmp(*argv, "limit") == 0) {

			NEXT_ARG();

			if (get_size(&limit, *argv)) {

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

				return -1;

			}

		} else if (strcmp(*argv, "ecn") == 0) {

			opt.flags |= TC_RED_ECN;

		} else if (strcmp(*argv, "harddrop") == 0) {

			opt.flags |= TC_RED_HARDDROP;

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

			explain();

			return -1;

		} else {

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

			explain();

			return -1;

		}

		argc--; argv++;

	}

	if (!opt.DPs || opt.def_DP == MAX_DPs) {

		fprintf(stderr, "Illegal gred setup parameters\n");

		return -1;

	}

	DPRINTF("TC_GRED: sending DPs=%u def_DP=%u\n", opt.DPs, opt.def_DP);

	n->nlmsg_flags |= NLM_F_CREATE;

	tail = addattr_nest(n, 1024, TCA_OPTIONS);

	addattr_l(n, 1024, TCA_GRED_DPS, &opt, sizeof(struct tc_gred_sopt));

	if (limit)

		addattr32(n, 1024, TCA_GRED_LIMIT, limit);

	addattr_nest_end(n, tail);

	return 0;

}

/*

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*/

static int gred_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n, const char *dev)

{

	struct rtattr *tail, *entry, *vqs;

	int ok = 0;

	struct tc_gred_qopt opt = { 0 };

	unsigned int burst = 0;

	unsigned int avpkt = 0;

	unsigned int flags = 0;

	double probability = 0.02;

	unsigned int rate = 0;

	int parm;

	__u8 sbuf[256];

	__u32 max_P;

	opt.DP = MAX_DPs;

	while (argc > 0) {

		if (strcmp(*argv, "limit") == 0) {

			NEXT_ARG();

			if (get_size(&opt.limit, *argv)) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "setup") == 0) {

			if (ok) {

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

				return -1;

			}

			return init_gred(qu, argc-1, argv+1, n);

		} else if (strcmp(*argv, "min") == 0) {

			NEXT_ARG();

			if (get_size(&opt.qth_min, *argv)) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "max") == 0) {

			NEXT_ARG();

			if (get_size(&opt.qth_max, *argv)) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "vq") == 0 ||

			   strcmp(*argv, "DP") == 0) {

			NEXT_ARG();

			if (get_unsigned(&opt.DP, *argv, 10)) {

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

				return -1;

			} else if (opt.DP >= MAX_DPs) {

				fprintf(stderr, "GRED: only %u VQs are currently supported\n",

					MAX_DPs);

				return -1;

			} /* need a better error check */

			ok++;

		} else if (strcmp(*argv, "burst") == 0) {

			NEXT_ARG();

			if (get_unsigned(&burst, *argv, 0)) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "avpkt") == 0) {

			NEXT_ARG();

			if (get_size(&avpkt, *argv)) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "probability") == 0) {

			NEXT_ARG();

			if (sscanf(*argv, "%lg", &probability) != 1) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "prio") == 0) {

			NEXT_ARG();

			opt.prio = strtol(*argv, (char **)NULL, 10);

			/* some error check here */

			ok++;

		} else if (strcmp(*argv, "bandwidth") == 0) {

			NEXT_ARG();

			if (strchr(*argv, '%')) {

				if (get_percent_rate(&rate, *argv, dev)) {

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

					return -1;

				}

			} else if (get_rate(&rate, *argv)) {

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

				return -1;

			}

			ok++;

		} else if (strcmp(*argv, "ecn") == 0) {

			flags |= TC_RED_ECN;

		} else if (strcmp(*argv, "harddrop") == 0) {

			flags |= TC_RED_HARDDROP;

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

			explain();

			return -1;

		} else {

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

			explain();

			return -1;

		}

		argc--; argv++;

	}

	if (!ok) {

		explain();

		return -1;

	}

	if (opt.DP == MAX_DPs || !opt.limit || !opt.qth_min || !opt.qth_max ||

	    !avpkt) {

		fprintf(stderr, "Required parameter (vq, limit, min, max, avpkt) is missing\n");

		return -1;

	}

	if (!burst) {

		burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);

		fprintf(stderr, "GRED: set burst to %u\n", burst);

	}

	if (!rate) {

		get_rate(&rate, "10Mbit");

		fprintf(stderr, "GRED: set bandwidth to 10Mbit\n");

	}

	if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {

		fprintf(stderr, "GRED: failed to calculate EWMA constant.\n");

		return -1;

	}

	if (parm >= 10)

		fprintf(stderr, "GRED: WARNING. Burst %u seems to be too large.\n",

		    burst);

	opt.Wlog = parm;

	if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {

		fprintf(stderr, "GRED: failed to calculate probability.\n");

		return -1;

	}

	opt.Plog = parm;

	if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0)

	    {

		fprintf(stderr, "GRED: failed to calculate idle damping table.\n");

		return -1;

	}

	opt.Scell_log = parm;

	tail = addattr_nest(n, 1024, TCA_OPTIONS);

	addattr_l(n, 1024, TCA_GRED_PARMS, &opt, sizeof(opt));

	addattr_l(n, 1024, TCA_GRED_STAB, sbuf, 256);

	max_P = probability * pow(2, 32);

	addattr32(n, 1024, TCA_GRED_MAX_P, max_P);

	vqs = addattr_nest(n, 1024, TCA_GRED_VQ_LIST);

	entry = addattr_nest(n, 1024, TCA_GRED_VQ_ENTRY);

	addattr32(n, 1024, TCA_GRED_VQ_DP, opt.DP);

	addattr32(n, 1024, TCA_GRED_VQ_FLAGS, flags);

	addattr_nest_end(n, entry);

	addattr_nest_end(n, vqs);

	addattr_nest_end(n, tail);

	return 0;

}

struct tc_gred_info {

	bool	flags_present;

	__u64	bytes;

	__u32	packets;

	__u32	backlog;

	__u32	prob_drop;

	__u32	prob_mark;

	__u32	forced_drop;

	__u32	forced_mark;

	__u32	pdrop;

	__u32	other;

	__u32	flags;

};

static void

gred_parse_vqs(struct tc_gred_info *info, struct rtattr *vqs)

{

	int rem = RTA_PAYLOAD(vqs);

	unsigned int offset = 0;

	while (rem > offset) {

		struct rtattr *tb_entry[TCA_GRED_VQ_ENTRY_MAX + 1] = {};

		struct rtattr *tb[TCA_GRED_VQ_MAX + 1] = {};

		struct rtattr *entry;

		unsigned int len;

		unsigned int dp;

		entry = RTA_DATA(vqs) + offset;

		parse_rtattr(tb_entry, TCA_GRED_VQ_ENTRY_MAX, entry,

			     rem - offset);

		len = RTA_LENGTH(RTA_PAYLOAD(entry));

		offset += len;

		if (!tb_entry[TCA_GRED_VQ_ENTRY]) {

			fprintf(stderr,

				"ERROR: Failed to parse Virtual Queue entry\n");

			continue;

		}

		parse_rtattr_nested(tb, TCA_GRED_VQ_MAX,

				    tb_entry[TCA_GRED_VQ_ENTRY]);

		if (!tb[TCA_GRED_VQ_DP]) {

			fprintf(stderr,

				"ERROR: Virtual Queue without DP attribute\n");

			continue;

		}

		dp = rta_getattr_u32(tb[TCA_GRED_VQ_DP]);

		if (tb[TCA_GRED_VQ_STAT_BYTES])

			info[dp].bytes =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_BYTES]);

		if (tb[TCA_GRED_VQ_STAT_PACKETS])

			info[dp].packets =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_PACKETS]);

		if (tb[TCA_GRED_VQ_STAT_BACKLOG])

			info[dp].backlog =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_BACKLOG]);

		if (tb[TCA_GRED_VQ_STAT_PROB_DROP])

			info[dp].prob_drop =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_PROB_DROP]);

		if (tb[TCA_GRED_VQ_STAT_PROB_MARK])

			info[dp].prob_mark =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_PROB_MARK]);

		if (tb[TCA_GRED_VQ_STAT_FORCED_DROP])

			info[dp].forced_drop =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_FORCED_DROP]);

		if (tb[TCA_GRED_VQ_STAT_FORCED_MARK])

			info[dp].forced_mark =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_FORCED_MARK]);

		if (tb[TCA_GRED_VQ_STAT_PDROP])

			info[dp].pdrop =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_PDROP]);

		if (tb[TCA_GRED_VQ_STAT_OTHER])

			info[dp].other =

				rta_getattr_u32(tb[TCA_GRED_VQ_STAT_OTHER]);

		info[dp].flags_present = !!tb[TCA_GRED_VQ_FLAGS];

		if (tb[TCA_GRED_VQ_FLAGS])

			info[dp].flags =

				rta_getattr_u32(tb[TCA_GRED_VQ_FLAGS]);

	}

}

static void

gred_print_stats(struct tc_gred_info *info, struct tc_gred_qopt *qopt)

{

	__u64 bytes = info ? info->bytes : qopt->bytesin;

	SPRINT_BUF(b1);

	if (!is_json_context())

		printf("\n  Queue size: ");

	print_uint(PRINT_JSON, "qave", NULL, qopt->qave);

	print_string(PRINT_FP, NULL, "average %s ",

		     sprint_size(qopt->qave, b1));

	print_uint(PRINT_JSON, "backlog", NULL, qopt->backlog);

	print_string(PRINT_FP, NULL, "current %s ",

		     sprint_size(qopt->backlog, b1));

	if (!is_json_context())

		printf("\n  Dropped packets: ");

	if (info) {

		print_uint(PRINT_ANY, "forced_drop", "forced %u ",

			   info->forced_drop);

		print_uint(PRINT_ANY, "prob_drop", "early %u ",

			   info->prob_drop);

		print_uint(PRINT_ANY, "pdrop", "pdrop %u ", info->pdrop);

		print_uint(PRINT_ANY, "other", "other %u ", info->other);

		if (!is_json_context())

			printf("\n  Marked packets: ");

		print_uint(PRINT_ANY, "forced_mark", "forced %u ",

			   info->forced_mark);

		print_uint(PRINT_ANY, "prob_mark", "early %u ",

			   info->prob_mark);

	} else {

		print_uint(PRINT_ANY, "forced_drop", "forced %u ",

			   qopt->forced);

		print_uint(PRINT_ANY, "prob_drop", "early %u ", qopt->early);

		print_uint(PRINT_ANY, "pdrop", "pdrop %u ", qopt->pdrop);

		print_uint(PRINT_ANY, "other", "other %u ", qopt->other);

	}

	if (!is_json_context())

		printf("\n  Total packets: ");

	print_uint(PRINT_ANY, "packets", "%u ", qopt->packets);

	print_uint(PRINT_JSON, "bytes", NULL, bytes);

	print_string(PRINT_FP, NULL, "(%s) ", sprint_size(bytes, b1));

}

static int gred_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)

{

	struct tc_gred_info infos[MAX_DPs] = {};

	struct rtattr *tb[TCA_GRED_MAX + 1];

	struct tc_gred_sopt *sopt;

	struct tc_gred_qopt *qopt;

	bool vq_info = false;

	__u32 *max_p = NULL;

	__u32 *limit = NULL;

	unsigned int i;

	SPRINT_BUF(b1);

	if (opt == NULL)

		return 0;

	parse_rtattr_nested(tb, TCA_GRED_MAX, opt);

	if (tb[TCA_GRED_PARMS] == NULL)

		return -1;

	if (tb[TCA_GRED_MAX_P] &&

	    RTA_PAYLOAD(tb[TCA_GRED_MAX_P]) >= sizeof(__u32) * MAX_DPs)

		max_p = RTA_DATA(tb[TCA_GRED_MAX_P]);

	if (tb[TCA_GRED_LIMIT] &&

	    RTA_PAYLOAD(tb[TCA_GRED_LIMIT]) == sizeof(__u32))

		limit = RTA_DATA(tb[TCA_GRED_LIMIT]);

	sopt = RTA_DATA(tb[TCA_GRED_DPS]);

	qopt = RTA_DATA(tb[TCA_GRED_PARMS]);

	if (RTA_PAYLOAD(tb[TCA_GRED_DPS]) < sizeof(*sopt) ||

	    RTA_PAYLOAD(tb[TCA_GRED_PARMS]) < sizeof(*qopt)*MAX_DPs) {

		fprintf(f, "\n GRED received message smaller than expected\n");

		return -1;

	}

	if (tb[TCA_GRED_VQ_LIST]) {

		gred_parse_vqs(infos, tb[TCA_GRED_VQ_LIST]);

		vq_info = true;

	}

	print_uint(PRINT_ANY, "dp_cnt", "vqs %u ", sopt->DPs);

	print_uint(PRINT_ANY, "dp_default", "default %u ", sopt->def_DP);

	if (sopt->grio)

		print_bool(PRINT_ANY, "grio", "grio ", true);

	else

		print_bool(PRINT_ANY, "grio", NULL, false);

	if (limit) {

		print_uint(PRINT_JSON, "limit", NULL, *limit);

		print_string(PRINT_FP, NULL, "limit %s ",

			     sprint_size(*limit, b1));

	}

	tc_red_print_flags(sopt->flags);

	open_json_array(PRINT_JSON, "vqs");

	for (i = 0; i < MAX_DPs; i++, qopt++) {

		if (qopt->DP >= MAX_DPs)

			continue;

		open_json_object(NULL);

		print_uint(PRINT_ANY, "vq", "\n vq %u ", qopt->DP);

		print_hhu(PRINT_ANY, "prio", "prio %hhu ", qopt->prio);

		print_uint(PRINT_JSON, "limit", NULL, qopt->limit);

		print_string(PRINT_FP, NULL, "limit %s ",

			     sprint_size(qopt->limit, b1));

		print_uint(PRINT_JSON, "min", NULL, qopt->qth_min);

		print_string(PRINT_FP, NULL, "min %s ",

			     sprint_size(qopt->qth_min, b1));

		print_uint(PRINT_JSON, "max", NULL, qopt->qth_max);

		print_string(PRINT_FP, NULL, "max %s ",

			     sprint_size(qopt->qth_max, b1));

		if (infos[i].flags_present)

			tc_red_print_flags(infos[i].flags);

		if (show_details) {

			print_uint(PRINT_ANY, "ewma", "ewma %u ", qopt->Wlog);

			if (max_p)

				print_float(PRINT_ANY, "probability",

					    "probability %lg ",

					    max_p[i] / pow(2, 32));

			else

				print_uint(PRINT_ANY, "Plog", "Plog %u ",

					   qopt->Plog);

			print_uint(PRINT_ANY, "Scell_log", "Scell_log %u ",

				   qopt->Scell_log);

		}

		if (show_stats)

			gred_print_stats(vq_info ? &infos[i] : NULL, qopt);

		close_json_object();

	}

	close_json_array(PRINT_JSON, "vqs");

	return 0;

}

struct qdisc_util gred_qdisc_util = {

	.id		= "gred",

	.parse_qopt	= gred_parse_opt,

	.print_qopt	= gred_print_opt,

};