Adding upstream version 5.7.1.upstream/5.7.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 534 insertions, 0 deletions

diff --git a/modules/stats/stats.c b/modules/stats/stats.c
new file mode 100644
index 0000000..ebb2877
--- /dev/null
+++ b/modules/stats/stats.c
@@ -0,0 +1,534 @@
+/*  Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ *  SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/**
+ * @file stats.c
+ * @brief Storage for various counters and metrics from query resolution.
+ *
+ * You can either reuse this module to compute statistics or store custom metrics
+ * in it via the extensions.
+ */
+
+#include <libknot/packet/pkt.h>
+#include <libknot/packet/wire.h>
+#include <libknot/descriptor.h>
+#include <ccan/json/json.h>
+#include <contrib/cleanup.h>
+#include <arpa/inet.h>
+#include <lua.h>
+
+#include "lib/generic/trie.h"
+#include "lib/layer/iterate.h"
+#include "lib/rplan.h"
+#include "lib/module.h"
+#include "lib/layer.h"
+#include "lib/resolve.h"
+
+/* Defaults */
+#define VERBOSE_MSG(qry, ...) kr_log_q(qry, STATISTICS,  __VA_ARGS__)
+#define FREQUENT_PSAMPLE  10 /* Sampling rate, 1 in N */
+#ifdef LRU_REP_SIZE
+ #define FREQUENT_COUNT LRU_REP_SIZE /* Size of frequent tables */
+#else
+ #define FREQUENT_COUNT  5000 /* Size of frequent tables */
+#endif
+#ifndef UPSTREAMS_COUNT
+ #define UPSTREAMS_COUNT  512 /* Size of recent upstreams */
+#endif
+
+/** @cond internal Fixed-size map of predefined metrics. */
+#define CONST_METRICS(X) \
+	X(answer,total) X(answer,noerror) X(answer,nodata) X(answer,nxdomain) X(answer,servfail) \
+	X(answer,cached) X(answer,1ms) X(answer,10ms) X(answer,50ms) X(answer,100ms) \
+	X(answer,250ms) X(answer,500ms) X(answer,1000ms) X(answer,1500ms) X(answer,slow) \
+	X(answer,aa) X(answer,tc) X(answer,rd) X(answer,ra) X(answer, ad) X(answer,cd) \
+	X(answer,edns0) X(answer,do) \
+	X(query,edns) X(query,dnssec) \
+	X(request,total) X(request,udp) X(request,tcp) X(request,xdp) \
+	X(request,dot) X(request,doh) X(request,internal) \
+	X(const,end)
+
+enum const_metric {
+	#define X(a,b) metric_ ## a ## _ ## b,
+	CONST_METRICS(X)
+	#undef X
+};
+struct const_metric_elm {
+	const char *key;
+	size_t val;
+};
+static struct const_metric_elm const_metrics[] = {
+	#define X(a,b) [metric_ ## a ## _ ## b] = { #a "." #b, 0 },
+	CONST_METRICS(X)
+	#undef X
+};
+/** @endcond */
+
+/** @internal LRU hash of most frequent names. */
+typedef lru_t(unsigned) namehash_t;
+typedef array_t(struct sockaddr_in6) addrlist_t;
+
+/** @internal Stats data structure. */
+struct stat_data {
+	trie_t *trie;
+	struct {
+		namehash_t *frequent;
+	} queries;
+	struct {
+		addrlist_t q;
+		size_t head;
+	} upstreams;
+};
+
+/** @internal We don't store/publish port, repurpose it for RTT instead. */
+#define sin6_rtt sin6_port
+
+/** @internal Add to const map counter */
+static inline void stat_const_add(struct stat_data *data, enum const_metric key, ssize_t incr)
+{
+	const_metrics[key].val += incr;
+}
+
+static int collect_answer(struct stat_data *data, knot_pkt_t *pkt)
+{
+	stat_const_add(data, metric_answer_total, 1);
+	/* Count per-rcode */
+	switch(knot_wire_get_rcode(pkt->wire)) {
+	case KNOT_RCODE_NOERROR:
+		if (knot_wire_get_ancount(pkt->wire) > 0)
+			stat_const_add(data, metric_answer_noerror, 1);
+		else
+			stat_const_add(data, metric_answer_nodata, 1);
+	break;
+	case KNOT_RCODE_NXDOMAIN: stat_const_add(data, metric_answer_nxdomain, 1); break;
+	case KNOT_RCODE_SERVFAIL: stat_const_add(data, metric_answer_servfail, 1); break;
+	default: break;
+	}
+
+	return kr_ok();
+}
+
+static inline int collect_key(char *key, const knot_dname_t *name, uint16_t type)
+{
+	memcpy(key, &type, sizeof(type));
+	int key_len = knot_dname_to_wire((uint8_t *)key + sizeof(type), name, KNOT_DNAME_MAXLEN);
+	if (key_len < 0) {
+		return kr_error(key_len);
+	}
+	return key_len + sizeof(type);
+}
+
+static void collect_sample(struct stat_data *data, struct kr_rplan *rplan)
+{
+	/* Sample key = {[2] type, [1-255] owner} */
+	char key[sizeof(uint16_t) + KNOT_DNAME_MAXLEN];
+	for (size_t i = 0; i < rplan->resolved.len; ++i) {
+		/* Sample queries leading to iteration */
+		struct kr_query *qry = rplan->resolved.at[i];
+		if (qry->flags.CACHED) {
+			continue;
+		}
+		/* Consider 1 in N for frequent sampling.
+		 * TODO: redesign the sampling approach. */
+		if (kr_rand_coin(1, FREQUENT_PSAMPLE)) {
+			int key_len = collect_key(key, qry->sname, qry->stype);
+			if (kr_fails_assert(key_len >= 0))
+				continue;
+			unsigned *count = lru_get_new(data->queries.frequent, key, key_len, NULL);
+			if (count)
+				*count += 1;
+		}
+	}
+}
+
+static int collect_rtt(kr_layer_t *ctx, knot_pkt_t *pkt)
+{
+	struct kr_request *req = ctx->req;
+	struct kr_query *qry = req->current_query;
+	if (qry->flags.CACHED || !req->upstream.transport) {
+		return ctx->state;
+	}
+
+	/* Push address and RTT to the ring buffer head */
+	struct kr_module *module = ctx->api->data;
+	struct stat_data *data = module->data;
+
+	/* Socket address is encoded into sockaddr_in6 struct that
+	 * unions with sockaddr_in and differ in sa_family */
+	struct sockaddr_in6 *e = &data->upstreams.q.at[data->upstreams.head];
+	const union kr_sockaddr *src = &req->upstream.transport->address;
+	switch (src->ip.sa_family) {
+		case AF_INET:  memcpy(e, &src->ip4, sizeof(src->ip4)); break;
+		case AF_INET6: memcpy(e, &src->ip6, sizeof(src->ip6)); break;
+		default: return ctx->state;
+	}
+	/* Replace port number with the RTT information (cap is UINT16_MAX milliseconds) */
+	e->sin6_rtt = req->upstream.rtt;
+
+	/* Advance ring buffer head */
+	data->upstreams.head = (data->upstreams.head + 1) % UPSTREAMS_COUNT;
+	return ctx->state;
+}
+
+static int collect_transport(kr_layer_t *ctx)
+{
+	struct kr_request *req = ctx->req;
+	struct kr_module *module = ctx->api->data;
+	struct stat_data *data = module->data;
+
+	stat_const_add(data, metric_request_total, 1);
+	if (req->qsource.dst_addr == NULL) {
+		stat_const_add(data, metric_request_internal, 1);
+		return ctx->state;
+	}
+
+	/**
+	 * Count each transport only once,
+	 * i.e. DoT does not count as TCP and XDP does not count as UDP.
+	 */
+	if (req->qsource.flags.http)
+		stat_const_add(data, metric_request_doh, 1);
+	else if (req->qsource.flags.tls)
+		stat_const_add(data, metric_request_dot, 1);
+	else if (req->qsource.flags.tcp)
+		stat_const_add(data, metric_request_tcp, 1);
+	else if (req->qsource.flags.xdp)
+		stat_const_add(data, metric_request_xdp, 1);
+	else
+		stat_const_add(data, metric_request_udp, 1);
+	return ctx->state;
+}
+
+static int collect(kr_layer_t *ctx)
+{
+	struct kr_request *param = ctx->req;
+	struct kr_module *module = ctx->api->data;
+	struct kr_rplan *rplan = &param->rplan;
+	struct stat_data *data = module->data;
+
+	collect_sample(data, rplan);
+	if (!param->answer) {
+		/* The answer is being dropped.  TODO: perhaps add some stat for this? */
+		return ctx->state;
+	}
+
+	/* Collect data on final answer */
+	collect_answer(data, param->answer);
+	/* Count cached and unresolved */
+	if (rplan->resolved.len > 0) {
+		/* Histogram of answer latency. */
+		struct kr_query *first = rplan->resolved.at[0];
+		uint64_t elapsed = kr_now() - first->timestamp_mono;
+		if (elapsed <= 1) {
+			stat_const_add(data, metric_answer_1ms, 1);
+		} else if (elapsed <= 10) {
+			stat_const_add(data, metric_answer_10ms, 1);
+		} else if (elapsed <= 50) {
+			stat_const_add(data, metric_answer_50ms, 1);
+		} else if (elapsed <= 100) {
+			stat_const_add(data, metric_answer_100ms, 1);
+		} else if (elapsed <= 250) {
+			stat_const_add(data, metric_answer_250ms, 1);
+		} else if (elapsed <= 500) {
+			stat_const_add(data, metric_answer_500ms, 1);
+		} else if (elapsed <= 1000) {
+			stat_const_add(data, metric_answer_1000ms, 1);
+		} else if (elapsed <= 1500) {
+			stat_const_add(data, metric_answer_1500ms, 1);
+		} else {
+			stat_const_add(data, metric_answer_slow, 1);
+		}
+		/* Observe the final query. */
+		struct kr_query *last = kr_rplan_last(rplan);
+		stat_const_add(data, metric_answer_cached, last->flags.CACHED);
+	}
+
+	/* Keep stats of all response header flags;
+	 * these don't return bool, so that's why we use !! */
+	stat_const_add(data, metric_answer_aa, !!knot_wire_get_aa(param->answer->wire));
+	stat_const_add(data, metric_answer_tc, !!knot_wire_get_tc(param->answer->wire));
+	stat_const_add(data, metric_answer_rd, !!knot_wire_get_rd(param->answer->wire));
+	stat_const_add(data, metric_answer_ra, !!knot_wire_get_ra(param->answer->wire));
+	stat_const_add(data, metric_answer_ad, !!knot_wire_get_ad(param->answer->wire));
+	stat_const_add(data, metric_answer_cd, !!knot_wire_get_cd(param->answer->wire));
+
+	/* EDNS0 stats */
+	stat_const_add(data, metric_answer_edns0, knot_pkt_has_edns(param->answer));
+	stat_const_add(data, metric_answer_do, knot_pkt_has_dnssec(param->answer));
+
+	/* Query parameters and transport mode */
+	/*
+		DEPRECATED
+		use new names metric_answer_edns0 and metric_answer_do
+	*/
+	stat_const_add(data, metric_query_edns, knot_pkt_has_edns(param->answer));
+	stat_const_add(data, metric_query_dnssec, knot_pkt_has_dnssec(param->answer));
+
+	return ctx->state;
+}
+
+/**
+ * Set nominal value of a key.
+ *
+ * Input:  { key, val }
+ *
+ */
+static char* stats_set(void *env, struct kr_module *module, const char *args)
+{
+	if (args == NULL)
+		return NULL;
+
+	struct stat_data *data = module->data;
+
+	auto_free char *pair = strdup(args);
+	char *val = strchr(pair, ' ');
+	if (val) {
+		*val = '\0';
+		size_t number = strtoul(val + 1, NULL, 10);
+		for (unsigned i = 0; i < metric_const_end; ++i) {
+			if (strcmp(const_metrics[i].key, pair) == 0) {
+				const_metrics[i].val = number;
+				return NULL;
+			}
+		}
+		trie_val_t *trie_val = trie_get_ins(data->trie, pair, strlen(pair));
+		*trie_val = (void *)number;
+	}
+
+	return NULL;
+}
+
+/**
+ * Retrieve metrics by key.
+ *
+ * Input:  string key
+ * Output: number value
+ */
+static char* stats_get(void *env, struct kr_module *module, const char *args)
+{
+	if (args == NULL)
+		return NULL;
+
+	struct stat_data *data = module->data;
+
+	/* Expecting CHAR_BIT to be 8, this is a safe bet */
+	char *ret = malloc(3 * sizeof(size_t) + 2);
+	if (!ret) {
+		return NULL;
+	}
+
+	/* Check if it exists in const map. */
+	for (unsigned i = 0; i < metric_const_end; ++i) {
+		if (strcmp(const_metrics[i].key, args) == 0) {
+			sprintf(ret, "%zu", const_metrics[i].val);
+			return ret;
+		}
+	}
+	/* Check in variable map */
+	trie_val_t *val = trie_get_try(data->trie, args, strlen(args));
+	if (!val) {
+		free(ret);
+		return NULL;
+	}
+	sprintf(ret, "%zu", (size_t) *val);
+	return ret;
+}
+
+/** Checks whether:
+ *   - `key` starts with `prefix`; OR
+ *   - The prefix is a wildcard, which is indicated by `prefix_len` being zero. */
+static inline bool key_matches_prefix(const char *key, size_t key_len,
+                                      const char *prefix, size_t prefix_len)
+{
+	return prefix_len == 0 || (prefix_len <= key_len && memcmp(key, prefix, prefix_len) == 0);
+}
+
+struct list_entry_context {
+	JsonNode *root;         /**< JSON object into which matching entries will be inserted. */
+	const char *key_prefix; /**< The prefix against which entries will be matched. */
+	size_t key_prefix_len;  /**< Prefix length. Prefix is a wildcard if zero. */
+};
+
+/** Inserts the entry with a matching key into the JSON object. */
+static int list_entry(const char *key, uint32_t key_len, trie_val_t *val, void *baton)
+{
+	struct list_entry_context *ctx = baton;
+	if (!key_matches_prefix(key, key_len, ctx->key_prefix, ctx->key_prefix_len))
+		return 0;
+	size_t number = (size_t) *val;
+	auto_free char *key_nt = strndup(key, key_len);
+	json_append_member(ctx->root, key_nt, json_mknumber(number));
+	return 0;
+}
+
+/**
+ * List observed metrics.
+ *
+ * Output: { key: val, ... }
+ */
+static char* stats_list(void *env, struct kr_module *module, const char *args)
+{
+	JsonNode *root = json_mkobject();
+	/* Walk const metrics map */
+	size_t args_len = args ? strlen(args) : 0;
+	for (unsigned i = 0; i < metric_const_end; ++i) {
+		struct const_metric_elm *elm = &const_metrics[i];
+		if (!args || strncmp(elm->key, args, args_len) == 0) {
+			json_append_member(root, elm->key, json_mknumber(elm->val));
+		}
+	}
+	struct list_entry_context ctx = {
+		.root = root,
+		.key_prefix = args,
+		.key_prefix_len = args_len
+	};
+	struct stat_data *data = module->data;
+	trie_apply_with_key(data->trie, list_entry, &ctx);
+	char *ret = json_encode(root);
+	json_delete(root);
+	return ret;
+}
+
+/** @internal Helper for dump_list: add a single namehash_t item to JSON. */
+static enum lru_apply_do dump_value(const char *key, uint len, unsigned *val, void *baton)
+{
+	uint16_t key_type = 0;
+	/* Extract query name, type and counter */
+	memcpy(&key_type, key, sizeof(key_type));
+	KR_DNAME_GET_STR(key_name, (uint8_t *)key + sizeof(key_type));
+	KR_RRTYPE_GET_STR(type_str, key_type);
+
+	/* Convert to JSON object */
+	JsonNode *json_val = json_mkobject();
+	json_append_member(json_val, "count", json_mknumber(*val));
+	json_append_member(json_val, "name",  json_mkstring(key_name));
+	json_append_member(json_val, "type",  json_mkstring(type_str));
+	json_append_element((JsonNode *)baton, json_val);
+	return LRU_APPLY_DO_NOTHING; // keep the item
+}
+/**
+ * List frequent names.
+ *
+ * Output: [{ count: <counter>, name: <qname>, type: <qtype>}, ... ]
+ */
+static char* dump_list(void *env, struct kr_module *module, const char *args, namehash_t *table)
+{
+	if (!table) {
+		return NULL;
+	}
+	JsonNode *root = json_mkarray();
+	lru_apply(table, dump_value, root);
+	char *ret = json_encode(root);
+	json_delete(root);
+	return ret;
+}
+
+static char* dump_frequent(void *env, struct kr_module *module, const char *args)
+{
+	struct stat_data *data = module->data;
+	return dump_list(env, module, args, data->queries.frequent);
+}
+
+static char* clear_frequent(void *env, struct kr_module *module, const char *args)
+{
+	struct stat_data *data = module->data;
+	lru_reset(data->queries.frequent);
+	return NULL;
+}
+
+static char* dump_upstreams(void *env, struct kr_module *module, const char *args)
+{
+	struct stat_data *data = module->data;
+	if (!data) {
+		return NULL;
+	}
+
+	/* Walk the ring backwards until AF_UNSPEC or we hit head. */
+	JsonNode *root = json_mkobject();
+	size_t head = data->upstreams.head;
+	for (size_t i = 1; i < UPSTREAMS_COUNT; ++i) {
+		size_t h = (UPSTREAMS_COUNT + head - i) % UPSTREAMS_COUNT;
+		struct sockaddr_in6 *e = &data->upstreams.q.at[h];
+		if (e->sin6_family == AF_UNSPEC) {
+			break;
+		}
+		/* Convert address to string */
+		char addr_str[INET6_ADDRSTRLEN];
+		const char *ret = inet_ntop(e->sin6_family, kr_inaddr((const struct sockaddr *)e), addr_str, sizeof(addr_str));
+		if (!ret) {
+			break;
+		}
+		/* Append to map with an array encoding RTTs */
+		JsonNode *json_val = json_find_member(root, addr_str);
+		if (!json_val) {
+			json_val = json_mkarray();
+			json_append_member(root, addr_str, json_val);
+		}
+		json_append_element(json_val, json_mknumber(e->sin6_rtt));
+	}
+
+	/* Encode and return */
+	char *ret = json_encode(root);
+	json_delete(root);
+	return ret;
+}
+
+KR_EXPORT
+int stats_init(struct kr_module *module)
+{
+	static kr_layer_api_t layer = {
+		.consume = &collect_rtt,
+		.finish = &collect,
+		.begin = &collect_transport,
+	};
+	/* Store module reference */
+	layer.data = module;
+	module->layer = &layer;
+
+	static const struct kr_prop props[] = {
+	    { &stats_set,     "set", "Set {key, val} metrics.", },
+	    { &stats_get,     "get", "Get metrics for given key.", },
+	    { &stats_list,    "list", "List observed metrics.", },
+	    { &dump_frequent, "frequent", "List most frequent queries.", },
+	    { &clear_frequent,"clear_frequent", "Clear frequent queries log.", },
+	    { &dump_upstreams,  "upstreams", "List recently seen authoritatives.", },
+	    { NULL, NULL, NULL }
+	};
+	module->props = props;
+
+	struct stat_data *data = calloc(1, sizeof(*data));
+	if (!data) {
+		return kr_error(ENOMEM);
+	}
+	data->trie = trie_create(NULL);
+	module->data = data;
+	lru_create(&data->queries.frequent, FREQUENT_COUNT, NULL, NULL);
+	/* Initialize ring buffer of recently visited upstreams */
+	array_init(data->upstreams.q);
+	if (array_reserve(data->upstreams.q, UPSTREAMS_COUNT) != 0) {
+		return kr_error(ENOMEM);
+	}
+	data->upstreams.q.len = UPSTREAMS_COUNT; /* signify we use the entries */
+	for (size_t i = 0; i < UPSTREAMS_COUNT; ++i) {
+		data->upstreams.q.at[i].sin6_family = AF_UNSPEC;
+	}
+	return kr_ok();
+}
+
+KR_EXPORT
+int stats_deinit(struct kr_module *module)
+{
+	struct stat_data *data = module->data;
+	if (data) {
+		trie_free(data->trie);
+		lru_free(data->queries.frequent);
+		array_clear(data->upstreams.q);
+		free(data);
+	}
+	return kr_ok();
+}
+
+KR_MODULE_EXPORT(stats)
+
+#undef VERBOSE_MSG