/* SPDX-License-Identifier: GPL-2.0 */
/* q_htb.c	Hierarchical Token Bucket
 *
 * Author:	Martin Devera, devik@cdi.cz
 */

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

#define HTB_TC_VER 0x30003
#if HTB_TC_VER >> 16 != TC_HTB_PROTOVER
#error "Different kernel and TC HTB versions"
#endif

static void explain(void)
{
	fprintf(stderr, "Usage: ... qdisc add ... htb [default N] [r2q N]\n"
		"                      [direct_qlen P] [offload]\n"
		" default  minor id of class to which unclassified packets are sent {0}\n"
		" r2q      DRR quantums are computed as rate in Bps/r2q {10}\n"
		" debug    string of 16 numbers each 0-3 {0}\n\n"
		" direct_qlen  Limit of the direct queue {in packets}\n"
		" offload  enable hardware offload\n"
		"... class add ... htb rate R1 [burst B1] [mpu B] [overhead O]\n"
		"                      [prio P] [slot S] [pslot PS]\n"
		"                      [ceil R2] [cburst B2] [mtu MTU] [quantum Q]\n"
		" rate     rate allocated to this class (class can still borrow)\n"
		" burst    max bytes burst which can be accumulated during idle period {computed}\n"
		" mpu      minimum packet size used in rate computations\n"
		" overhead per-packet size overhead used in rate computations\n"
		" linklay  adapting to a linklayer e.g. atm\n"
		" ceil     definite upper class rate (no borrows) {rate}\n"
		" cburst   burst but for ceil {computed}\n"
		" mtu      max packet size we create rate map for {1600}\n"
		" prio     priority of leaf; lower are served first {0}\n"
		" quantum  how much bytes to serve from leaf at once {use r2q}\n"
		"\nTC HTB version %d.%d\n", HTB_TC_VER>>16, HTB_TC_VER&0xffff
		);
}

static void explain1(char *arg)
{
	fprintf(stderr, "Illegal \"%s\"\n", arg);
	explain();
}

static int htb_parse_opt(const struct qdisc_util *qu, int argc,
			 char **argv, struct nlmsghdr *n, const char *dev)
{
	unsigned int direct_qlen = ~0U;
	struct tc_htb_glob opt = {
		.rate2quantum = 10,
		.version = 3,
	};
	struct rtattr *tail;
	unsigned int i; char *p;
	bool offload = false;

	while (argc > 0) {
		if (matches(*argv, "r2q") == 0) {
			NEXT_ARG();
			if (get_u32(&opt.rate2quantum, *argv, 10)) {
				explain1("r2q"); return -1;
			}
		} else if (matches(*argv, "default") == 0) {
			NEXT_ARG();
			if (get_u32(&opt.defcls, *argv, 16)) {
				explain1("default"); return -1;
			}
		} else if (matches(*argv, "debug") == 0) {
			NEXT_ARG(); p = *argv;
			for (i = 0; i < 16; i++, p++) {
				if (*p < '0' || *p > '3') break;
				opt.debug |= (*p-'0')<<(2*i);
			}
		} else if (matches(*argv, "direct_qlen") == 0) {
			NEXT_ARG();
			if (get_u32(&direct_qlen, *argv, 10)) {
				explain1("direct_qlen"); return -1;
			}
		} else if (matches(*argv, "offload") == 0) {
			offload = true;
		} else {
			fprintf(stderr, "What is \"%s\"?\n", *argv);
			explain();
			return -1;
		}
		argc--; argv++;
	}
	tail = addattr_nest(n, 1024, TCA_OPTIONS);
	addattr_l(n, 2024, TCA_HTB_INIT, &opt, NLMSG_ALIGN(sizeof(opt)));
	if (direct_qlen != ~0U)
		addattr_l(n, 2024, TCA_HTB_DIRECT_QLEN,
			  &direct_qlen, sizeof(direct_qlen));
	if (offload)
		addattr(n, 2024, TCA_HTB_OFFLOAD);
	addattr_nest_end(n, tail);
	return 0;
}

static int htb_parse_class_opt(const struct qdisc_util *qu, int argc, char **argv,
			       struct nlmsghdr *n, const char *dev)
{
	struct tc_htb_opt opt = {};
	__u32 rtab[256], ctab[256];
	unsigned buffer = 0, cbuffer = 0;
	int cell_log =  -1, ccell_log = -1;
	unsigned int mtu = 1600; /* eth packet len */
	unsigned short mpu = 0;
	unsigned short overhead = 0;
	unsigned int linklayer  = LINKLAYER_ETHERNET; /* Assume ethernet */
	struct rtattr *tail;
	__u64 ceil64 = 0, rate64 = 0;
	char *param;

	while (argc > 0) {
		if (matches(*argv, "prio") == 0) {
			NEXT_ARG();
			if (get_u32(&opt.prio, *argv, 10)) {
				explain1("prio"); return -1;
			}
		} else if (matches(*argv, "mtu") == 0) {
			NEXT_ARG();
			if (get_u32(&mtu, *argv, 10)) {
				explain1("mtu"); return -1;
			}
		} else if (matches(*argv, "mpu") == 0) {
			NEXT_ARG();
			if (get_u16(&mpu, *argv, 10)) {
				explain1("mpu"); return -1;
			}
		} else if (matches(*argv, "overhead") == 0) {
			NEXT_ARG();
			if (get_u16(&overhead, *argv, 10)) {
				explain1("overhead"); return -1;
			}
		} else if (matches(*argv, "linklayer") == 0) {
			NEXT_ARG();
			if (get_linklayer(&linklayer, *argv)) {
				explain1("linklayer"); return -1;
			}
		} else if (matches(*argv, "quantum") == 0) {
			NEXT_ARG();
			if (get_u32(&opt.quantum, *argv, 10)) {
				explain1("quantum"); return -1;
			}
		} else if (matches(*argv, "burst") == 0 ||
			   strcmp(*argv, "buffer") == 0 ||
			   strcmp(*argv, "maxburst") == 0) {
			param = *argv;
			NEXT_ARG();
			if (get_size_and_cell(&buffer, &cell_log, *argv) < 0) {
				explain1(param);
				return -1;
			}
		} else if (matches(*argv, "cburst") == 0 ||
			   strcmp(*argv, "cbuffer") == 0 ||
			   strcmp(*argv, "cmaxburst") == 0) {
			param = *argv;
			NEXT_ARG();
			if (get_size_and_cell(&cbuffer, &ccell_log, *argv) < 0) {
				explain1(param);
				return -1;
			}
		} else if (strcmp(*argv, "ceil") == 0) {
			NEXT_ARG();
			if (ceil64) {
				fprintf(stderr, "Double \"ceil\" spec\n");
				return -1;
			}
			if (strchr(*argv, '%')) {
				if (get_percent_rate64(&ceil64, *argv, dev)) {
					explain1("ceil");
					return -1;
				}
			} else if (get_rate64(&ceil64, *argv)) {
				explain1("ceil");
				return -1;
			}
		} else if (strcmp(*argv, "rate") == 0) {
			NEXT_ARG();
			if (rate64) {
				fprintf(stderr, "Double \"rate\" spec\n");
				return -1;
			}
			if (strchr(*argv, '%')) {
				if (get_percent_rate64(&rate64, *argv, dev)) {
					explain1("rate");
					return -1;
				}
			} else if (get_rate64(&rate64, *argv)) {
				explain1("rate");
				return -1;
			}
		} else if (strcmp(*argv, "help") == 0) {
			explain();
			return -1;
		} else {
			fprintf(stderr, "What is \"%s\"?\n", *argv);
			explain();
			return -1;
		}
		argc--; argv++;
	}

	if (!rate64) {
		fprintf(stderr, "\"rate\" is required.\n");
		return -1;
	}
	/* if ceil params are missing, use the same as rate */
	if (!ceil64)
		ceil64 = rate64;

	opt.rate.rate = (rate64 >= (1ULL << 32)) ? ~0U : rate64;
	opt.ceil.rate = (ceil64 >= (1ULL << 32)) ? ~0U : ceil64;

	/* compute minimal allowed burst from rate; mtu is added here to make
	   sure that buffer is larger than mtu and to have some safeguard space */
	if (!buffer)
		buffer = rate64 / get_hz() + mtu;
	if (!cbuffer)
		cbuffer = ceil64 / get_hz() + mtu;

	opt.ceil.overhead = overhead;
	opt.rate.overhead = overhead;

	opt.ceil.mpu = mpu;
	opt.rate.mpu = mpu;

	if (tc_calc_rtable(&opt.rate, rtab, cell_log, mtu, linklayer) < 0) {
		fprintf(stderr, "htb: failed to calculate rate table.\n");
		return -1;
	}
	opt.buffer = tc_calc_xmittime(rate64, buffer);

	if (tc_calc_rtable(&opt.ceil, ctab, ccell_log, mtu, linklayer) < 0) {
		fprintf(stderr, "htb: failed to calculate ceil rate table.\n");
		return -1;
	}
	opt.cbuffer = tc_calc_xmittime(ceil64, cbuffer);

	tail = addattr_nest(n, 1024, TCA_OPTIONS);

	if (rate64 >= (1ULL << 32))
		addattr_l(n, 1124, TCA_HTB_RATE64, &rate64, sizeof(rate64));

	if (ceil64 >= (1ULL << 32))
		addattr_l(n, 1224, TCA_HTB_CEIL64, &ceil64, sizeof(ceil64));

	addattr_l(n, 2024, TCA_HTB_PARMS, &opt, sizeof(opt));
	addattr_l(n, 3024, TCA_HTB_RTAB, rtab, 1024);
	addattr_l(n, 4024, TCA_HTB_CTAB, ctab, 1024);
	addattr_nest_end(n, tail);
	return 0;
}

static int htb_print_opt(const struct qdisc_util *qu, FILE *f, struct rtattr *opt)
{
	struct rtattr *tb[TCA_HTB_MAX + 1];
	struct tc_htb_opt *hopt;
	struct tc_htb_glob *gopt;
	double buffer, cbuffer;
	unsigned int linklayer;
	__u64 rate64, ceil64;

	SPRINT_BUF(b1);
	SPRINT_BUF(b3);

	if (opt == NULL)
		return 0;

	parse_rtattr_nested(tb, TCA_HTB_MAX, opt);

	if (tb[TCA_HTB_PARMS]) {
		hopt = RTA_DATA(tb[TCA_HTB_PARMS]);
		if (RTA_PAYLOAD(tb[TCA_HTB_PARMS])  < sizeof(*hopt)) return -1;

		if (!hopt->level) {
			print_int(PRINT_ANY, "prio", "prio %d ", (int)hopt->prio);
			if (show_details)
				print_int(PRINT_ANY, "quantum", "quantum %d ",
					  (int)hopt->quantum);
		}

		rate64 = hopt->rate.rate;
		if (tb[TCA_HTB_RATE64] &&
		    RTA_PAYLOAD(tb[TCA_HTB_RATE64]) >= sizeof(rate64)) {
			rate64 = rta_getattr_u64(tb[TCA_HTB_RATE64]);
		}

		ceil64 = hopt->ceil.rate;
		if (tb[TCA_HTB_CEIL64] &&
		    RTA_PAYLOAD(tb[TCA_HTB_CEIL64]) >= sizeof(ceil64))
			ceil64 = rta_getattr_u64(tb[TCA_HTB_CEIL64]);

		tc_print_rate(PRINT_ANY, "rate", "rate %s ", rate64);
		if (hopt->rate.overhead)
			print_uint(PRINT_ANY, "overhead", "overhead %u ", hopt->rate.overhead);
		buffer = tc_calc_xmitsize(rate64, hopt->buffer);

		tc_print_rate(PRINT_ANY, "ceil", "ceil %s ", ceil64);
		cbuffer = tc_calc_xmitsize(ceil64, hopt->cbuffer);
		linklayer = (hopt->rate.linklayer & TC_LINKLAYER_MASK);
		if (linklayer > TC_LINKLAYER_ETHERNET || show_details)
			print_string(PRINT_ANY, "linklayer", "linklayer %s ",
				     sprint_linklayer(linklayer, b3));
		if (show_details) {
			print_size(PRINT_ANY, "burst", "burst %s/", buffer);
			print_uint(PRINT_ANY, "burst_cell", "%u", 1<<hopt->rate.cell_log);
			print_size(PRINT_ANY, "mpu_rate", "mpu %s ", hopt->rate.mpu);
			print_size(PRINT_ANY, "cburst", "cburst %s/", cbuffer);
			print_uint(PRINT_ANY, "cburst_cell", "%u", 1<<hopt->ceil.cell_log);
			print_size(PRINT_ANY, "mpu_ceil", "mpu %s ", hopt->ceil.mpu);
			print_int(PRINT_ANY, "level", "level %d ", (int)hopt->level);
		} else {
			print_size(PRINT_ANY, "burst", "burst %s ", buffer);
			print_size(PRINT_ANY, "cburst", "cburst %s", cbuffer);
		}
		if (show_raw)
			fprintf(f, "buffer [%08x] cbuffer [%08x] ",
				hopt->buffer, hopt->cbuffer);
	}
	if (tb[TCA_HTB_INIT]) {
		gopt = RTA_DATA(tb[TCA_HTB_INIT]);
		if (RTA_PAYLOAD(tb[TCA_HTB_INIT])  < sizeof(*gopt)) return -1;

		print_int(PRINT_ANY, "r2q", "r2q %d", gopt->rate2quantum);
		print_0xhex(PRINT_ANY, "default", " default %#llx", gopt->defcls);
		print_uint(PRINT_ANY, "direct_packets_stat",
			   " direct_packets_stat %u", gopt->direct_pkts);
		if (show_details) {
			sprintf(b1, "%d.%d", gopt->version >> 16, gopt->version & 0xffff);
			print_string(PRINT_ANY, "ver", " ver %s", b1);
		}
	}
	if (tb[TCA_HTB_DIRECT_QLEN] &&
	    RTA_PAYLOAD(tb[TCA_HTB_DIRECT_QLEN]) >= sizeof(__u32)) {
		__u32 direct_qlen = rta_getattr_u32(tb[TCA_HTB_DIRECT_QLEN]);

		print_uint(PRINT_ANY, "direct_qlen", " direct_qlen %u",
			   direct_qlen);
	}
	if (tb[TCA_HTB_OFFLOAD])
		print_null(PRINT_ANY, "offload", " offload", NULL);
	return 0;
}

static int htb_print_xstats(const struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
{
	struct tc_htb_xstats *st;

	if (xstats == NULL)
		return 0;

	if (RTA_PAYLOAD(xstats) < sizeof(*st))
		return -1;

	st = RTA_DATA(xstats);
	print_uint(PRINT_ANY, "lended", " lended: %u ", st->lends);
	print_uint(PRINT_ANY, "borrowed", "borrowed: %u ", st->borrows);
	print_uint(PRINT_ANY, "giants", "giants: %u", st->giants);
	print_nl();
	print_int(PRINT_ANY, "tokens", " tokens: %d ", st->tokens);
	print_int(PRINT_ANY, "ctokens", "ctokens: %d", st->ctokens);
	print_nl();
	return 0;
}

struct qdisc_util htb_qdisc_util = {
	.id		= "htb",
	.parse_qopt	= htb_parse_opt,
	.print_qopt	= htb_print_opt,
	.print_xstats	= htb_print_xstats,
	.parse_copt	= htb_parse_class_opt,
	.print_copt	= htb_print_opt,
};