tc: add support for FQ-PIE packet scheduler

This patch adds support for the FQ-PIE packet Scheduler

Principles:
  - Packets are classified on flows.
  - This is a Stochastic model (as we use a hash, several flows might
                                be hashed to the same slot)
  - Each flow has a PIE managed queue.
  - Flows are linked onto two (Round Robin) lists,
    so that new flows have priority on old ones.
  - For a given flow, packets are not reordered.
  - Drops during enqueue only.
  - ECN capability is off by default.
  - ECN threshold (if ECN is enabled) is at 10% by default.
  - Uses timestamps to calculate queue delay by default.

Usage:
tc qdisc ... fq_pie [ limit PACKETS ] [ flows NUMBER ]
                    [ target TIME ] [ tupdate TIME ]
                    [ alpha NUMBER ] [ beta NUMBER ]
                    [ quantum BYTES ] [ memory_limit BYTES ]
                    [ ecn_prob PERCENTAGE ] [ [no]ecn ]
                    [ [no]bytemode ] [ [no_]dq_rate_estimator ]

defaults:
  limit: 10240 packets, flows: 1024
  target: 15 ms, tupdate: 15 ms (in jiffies)
  alpha: 1/8, beta : 5/4
  quantum: device MTU, memory_limit: 32 Mb
  ecnprob: 10%, ecn: off
  bytemode: off, dq_rate_estimator: off

Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Sachin D. Patil <sdp.sachin@gmail.com>
Signed-off-by: V. Saicharan <vsaicharan1998@gmail.com>
Signed-off-by: Mohit Bhasi <mohitbhasi1998@gmail.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

1 files changed, 318 insertions, 0 deletions

diff --git a/tc/q_fq_pie.c b/tc/q_fq_pie.c
new file mode 100644
index 00000000..c136cd1a
--- /dev/null
+++ b/tc/q_fq_pie.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Flow Queue PIE
+ *
+ * Copyright (C) 2019 Mohit P. Tahiliani <tahiliani@nitk.edu.in>
+ * Copyright (C) 2019 Sachin D. Patil <sdp.sachin@gmail.com>
+ * Copyright (C) 2019 V. Saicharan <vsaicharan1998@gmail.com>
+ * Copyright (C) 2019 Mohit Bhasi <mohitbhasi1998@gmail.com>
+ * Copyright (C) 2019 Leslie Monis <lesliemonis@gmail.com>
+ * Copyright (C) 2019 Gautam Ramakrishnan <gautamramk@gmail.com>
+ */
+
+#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"
+
+static void explain(void)
+{
+	fprintf(stderr,
+		"Usage: ... fq_pie [ limit PACKETS ] [ flows NUMBER ]\n"
+		"                  [ target TIME ] [ tupdate TIME ]\n"
+		"                  [ alpha NUMBER ] [ beta NUMBER ]\n"
+		"                  [ quantum BYTES ] [ memory_limit BYTES ]\n"
+		"                  [ ecn_prob PERCENTAGE ] [ [no]ecn ]\n"
+		"                  [ [no]bytemode ] [ [no_]dq_rate_estimator ]\n");
+}
+
+#define ALPHA_MAX 32
+#define BETA_MAX 32
+
+static int fq_pie_parse_opt(struct qdisc_util *qu, int argc, char **argv,
+			    struct nlmsghdr *n, const char *dev)
+{
+	unsigned int limit = 0;
+	unsigned int flows = 0;
+	unsigned int target = 0;
+	unsigned int tupdate = 0;
+	unsigned int alpha = 0;
+	unsigned int beta = 0;
+	unsigned int quantum = 0;
+	unsigned int memory_limit = 0;
+	unsigned int ecn_prob = 0;
+	int ecn = -1;
+	int bytemode = -1;
+	int dq_rate_estimator = -1;
+	struct rtattr *tail;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "limit") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&limit, *argv, 0)) {
+				fprintf(stderr, "Illegal \"limit\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "flows") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&flows, *argv, 0)) {
+				fprintf(stderr, "Illegal \"flows\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "target") == 0) {
+			NEXT_ARG();
+			if (get_time(&target, *argv)) {
+				fprintf(stderr, "Illegal \"target\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "tupdate") == 0) {
+			NEXT_ARG();
+			if (get_time(&tupdate, *argv)) {
+				fprintf(stderr, "Illegal \"tupdate\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "alpha") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&alpha, *argv, 0) ||
+			    alpha > ALPHA_MAX) {
+				fprintf(stderr, "Illegal \"alpha\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "beta") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&beta, *argv, 0) ||
+			    beta > BETA_MAX) {
+				fprintf(stderr, "Illegal \"beta\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "quantum") == 0) {
+			NEXT_ARG();
+			if (get_size(&quantum, *argv)) {
+				fprintf(stderr, "Illegal \"quantum\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "memory_limit") == 0) {
+			NEXT_ARG();
+			if (get_size(&memory_limit, *argv)) {
+				fprintf(stderr, "Illegal \"memory_limit\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "ecn_prob") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&ecn_prob, *argv, 0) ||
+			    ecn_prob >= 100) {
+				fprintf(stderr, "Illegal \"ecn_prob\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "ecn") == 0) {
+			ecn = 1;
+		} else if (strcmp(*argv, "noecn") == 0) {
+			ecn = 0;
+		} else if (strcmp(*argv, "bytemode") == 0) {
+			bytemode = 1;
+		} else if (strcmp(*argv, "nobytemode") == 0) {
+			bytemode = 0;
+		} else if (strcmp(*argv, "dq_rate_estimator") == 0) {
+			dq_rate_estimator = 1;
+		} else if (strcmp(*argv, "no_dq_rate_estimator") == 0) {
+			dq_rate_estimator = 0;
+		} else if (strcmp(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+
+		argc--;
+		argv++;
+	}
+
+	tail = addattr_nest(n, 1024, TCA_OPTIONS | NLA_F_NESTED);
+	if (limit)
+		addattr_l(n, 1024, TCA_FQ_PIE_LIMIT, &limit, sizeof(limit));
+	if (flows)
+		addattr_l(n, 1024, TCA_FQ_PIE_FLOWS, &flows, sizeof(flows));
+	if (target)
+		addattr_l(n, 1024, TCA_FQ_PIE_TARGET, &target, sizeof(target));
+	if (tupdate)
+		addattr_l(n, 1024, TCA_FQ_PIE_TUPDATE, &tupdate,
+			  sizeof(tupdate));
+	if (alpha)
+		addattr_l(n, 1024, TCA_FQ_PIE_ALPHA, &alpha, sizeof(alpha));
+	if (beta)
+		addattr_l(n, 1024, TCA_FQ_PIE_BETA, &beta, sizeof(beta));
+	if (quantum)
+		addattr_l(n, 1024, TCA_FQ_PIE_QUANTUM, &quantum,
+			  sizeof(quantum));
+	if (memory_limit)
+		addattr_l(n, 1024, TCA_FQ_PIE_MEMORY_LIMIT, &memory_limit,
+			  sizeof(memory_limit));
+	if (ecn_prob)
+		addattr_l(n, 1024, TCA_FQ_PIE_ECN_PROB, &ecn_prob,
+			  sizeof(ecn_prob));
+	if (ecn != -1)
+		addattr_l(n, 1024, TCA_FQ_PIE_ECN, &ecn, sizeof(ecn));
+	if (bytemode != -1)
+		addattr_l(n, 1024, TCA_FQ_PIE_BYTEMODE, &bytemode,
+			  sizeof(bytemode));
+	if (dq_rate_estimator != -1)
+		addattr_l(n, 1024, TCA_FQ_PIE_DQ_RATE_ESTIMATOR,
+			  &dq_rate_estimator, sizeof(dq_rate_estimator));
+	addattr_nest_end(n, tail);
+
+	return 0;
+}
+
+static int fq_pie_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+	struct rtattr *tb[TCA_FQ_PIE_MAX + 1];
+	unsigned int limit = 0;
+	unsigned int flows = 0;
+	unsigned int target = 0;
+	unsigned int tupdate = 0;
+	unsigned int alpha = 0;
+	unsigned int beta = 0;
+	unsigned int quantum = 0;
+	unsigned int memory_limit = 0;
+	unsigned int ecn_prob = 0;
+	int ecn = -1;
+	int bytemode = -1;
+	int dq_rate_estimator = -1;
+
+	SPRINT_BUF(b1);
+
+	if (opt == NULL)
+		return 0;
+
+	parse_rtattr_nested(tb, TCA_FQ_PIE_MAX, opt);
+
+	if (tb[TCA_FQ_PIE_LIMIT] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_LIMIT]) >= sizeof(__u32)) {
+		limit = rta_getattr_u32(tb[TCA_FQ_PIE_LIMIT]);
+		print_uint(PRINT_ANY, "limit", "limit %up ", limit);
+	}
+	if (tb[TCA_FQ_PIE_FLOWS] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_FLOWS]) >= sizeof(__u32)) {
+		flows = rta_getattr_u32(tb[TCA_FQ_PIE_FLOWS]);
+		print_uint(PRINT_ANY, "flows", "flows %u ", flows);
+	}
+	if (tb[TCA_FQ_PIE_TARGET] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_TARGET]) >= sizeof(__u32)) {
+		target = rta_getattr_u32(tb[TCA_FQ_PIE_TARGET]);
+		print_uint(PRINT_JSON, "target", NULL, target);
+		print_string(PRINT_FP, NULL, "target %s ",
+			     sprint_time(target, b1));
+	}
+	if (tb[TCA_FQ_PIE_TUPDATE] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_TUPDATE]) >= sizeof(__u32)) {
+		tupdate = rta_getattr_u32(tb[TCA_FQ_PIE_TUPDATE]);
+		print_uint(PRINT_JSON, "tupdate", NULL, tupdate);
+		print_string(PRINT_FP, NULL, "tupdate %s ",
+			     sprint_time(tupdate, b1));
+	}
+	if (tb[TCA_FQ_PIE_ALPHA] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_ALPHA]) >= sizeof(__u32)) {
+		alpha = rta_getattr_u32(tb[TCA_FQ_PIE_ALPHA]);
+		print_uint(PRINT_ANY, "alpha", "alpha %u ", alpha);
+	}
+	if (tb[TCA_FQ_PIE_BETA] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_BETA]) >= sizeof(__u32)) {
+		beta = rta_getattr_u32(tb[TCA_FQ_PIE_BETA]);
+		print_uint(PRINT_ANY, "beta", "beta %u ", beta);
+	}
+	if (tb[TCA_FQ_PIE_QUANTUM] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_QUANTUM]) >= sizeof(__u32)) {
+		quantum = rta_getattr_u32(tb[TCA_FQ_PIE_QUANTUM]);
+		print_uint(PRINT_JSON, "quantum", NULL, quantum);
+		print_string(PRINT_FP, NULL, "quantum %s ",
+			     sprint_size(quantum, b1));
+	}
+	if (tb[TCA_FQ_PIE_MEMORY_LIMIT] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_MEMORY_LIMIT]) >= sizeof(__u32)) {
+		memory_limit = rta_getattr_u32(tb[TCA_FQ_PIE_MEMORY_LIMIT]);
+		print_uint(PRINT_JSON, "memory_limit", NULL, memory_limit);
+		print_string(PRINT_FP, NULL, "memory_limit %s ",
+			     sprint_size(memory_limit, b1));
+	}
+	if (tb[TCA_FQ_PIE_ECN_PROB] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_ECN_PROB]) >= sizeof(__u32)) {
+		ecn_prob = rta_getattr_u32(tb[TCA_FQ_PIE_ECN_PROB]);
+		print_uint(PRINT_ANY, "ecn_prob", "ecn_prob %u ", ecn_prob);
+	}
+	if (tb[TCA_FQ_PIE_ECN] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_ECN]) >= sizeof(__u32)) {
+		ecn = rta_getattr_u32(tb[TCA_FQ_PIE_ECN]);
+		if (ecn)
+			print_bool(PRINT_ANY, "ecn", "ecn ", true);
+	}
+	if (tb[TCA_FQ_PIE_BYTEMODE] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_BYTEMODE]) >= sizeof(__u32)) {
+		bytemode = rta_getattr_u32(tb[TCA_FQ_PIE_BYTEMODE]);
+		if (bytemode)
+			print_bool(PRINT_ANY, "bytemode", "bytemode ", true);
+	}
+	if (tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR] &&
+	    RTA_PAYLOAD(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]) >= sizeof(__u32)) {
+		dq_rate_estimator =
+			rta_getattr_u32(tb[TCA_FQ_PIE_DQ_RATE_ESTIMATOR]);
+		if (dq_rate_estimator)
+			print_bool(PRINT_ANY, "dq_rate_estimator",
+				   "dq_rate_estimator ", true);
+	}
+
+	return 0;
+}
+
+static int fq_pie_print_xstats(struct qdisc_util *qu, FILE *f,
+			       struct rtattr *xstats)
+{
+	struct tc_fq_pie_xstats _st = {}, *st;
+
+	if (xstats == NULL)
+		return 0;
+
+	st = RTA_DATA(xstats);
+	if (RTA_PAYLOAD(xstats) < sizeof(*st)) {
+		memcpy(&_st, st, RTA_PAYLOAD(xstats));
+		st = &_st;
+	}
+
+	print_uint(PRINT_ANY, "pkts_in", "  pkts_in %u",
+		   st->packets_in);
+	print_uint(PRINT_ANY, "overlimit", " overlimit %u",
+		   st->overlimit);
+	print_uint(PRINT_ANY, "overmemory", " overmemory %u",
+		   st->overmemory);
+	print_uint(PRINT_ANY, "dropped", " dropped %u",
+		   st->dropped);
+	print_uint(PRINT_ANY, "ecn_mark", " ecn_mark %u",
+		   st->ecn_mark);
+	print_nl();
+	print_uint(PRINT_ANY, "new_flow_count", "  new_flow_count %u",
+		   st->new_flow_count);
+	print_uint(PRINT_ANY, "new_flows_len", " new_flows_len %u",
+		   st->new_flows_len);
+	print_uint(PRINT_ANY, "old_flows_len", " old_flows_len %u",
+		   st->old_flows_len);
+	print_uint(PRINT_ANY, "memory_used", " memory_used %u",
+		   st->memory_usage);
+
+	return 0;
+
+}
+
+struct qdisc_util fq_pie_qdisc_util = {
+	.id		= "fq_pie",
+	.parse_qopt	= fq_pie_parse_opt,
+	.print_qopt	= fq_pie_print_opt,
+	.print_xstats	= fq_pie_print_xstats,
+};