Adding upstream version 5.6.0.upstream/5.6.0upstream

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

1 files changed, 280 insertions, 0 deletions

diff --git a/utils/cache_gc/db.c b/utils/cache_gc/db.c
new file mode 100644
index 0000000..fc4a2fd
--- /dev/null
+++ b/utils/cache_gc/db.c
@@ -0,0 +1,280 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include "db.h"
+
+#include "lib/cache/cdb_lmdb.h"
+#include "lib/cache/impl.h"
+
+#include <ctype.h>
+#include <time.h>
+#include <sys/stat.h>
+
+int kr_gc_cache_open(const char *cache_path, struct kr_cache *kres_db,
+		     knot_db_t ** libknot_db)
+{
+	char cache_data[strlen(cache_path) + 10];
+	snprintf(cache_data, sizeof(cache_data), "%s/data.mdb", cache_path);
+
+	struct stat st = { 0 };
+	if (stat(cache_path, &st) || !(st.st_mode & S_IFDIR)
+	    || stat(cache_data, &st)) {
+		printf("Error: %s does not exist or is not a LMDB.\n", cache_path);
+		return -ENOENT;
+	}
+
+	struct kr_cdb_opts opts = { .path = cache_path, .maxsize = 0/*don't resize*/ };
+
+	int ret = kr_cache_open(kres_db, NULL, &opts, NULL);
+	if (ret || kres_db->db == NULL) {
+		printf("Error opening Resolver cache (%s).\n", kr_strerror(ret));
+		return -EINVAL;
+	}
+
+	*libknot_db = kr_cdb_pt2knot_db_t(kres_db->db);
+	if (*libknot_db == NULL) {
+		printf("Out of memory.\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+int kr_gc_cache_check_health(struct kr_cache *kres_db, knot_db_t ** libknot_db)
+{
+	int ret = kr_cache_check_health(kres_db, 0);
+	if (ret == 0) {
+		return 0;
+	} else if (ret != 1) {
+		kr_gc_cache_close(kres_db, *libknot_db);
+		return ret;
+	}
+	/* Cache was reopen. */
+	free(*libknot_db);
+	*libknot_db = kr_cdb_pt2knot_db_t(kres_db->db);
+	if (*libknot_db == NULL) {
+		printf("Out of memory.\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void kr_gc_cache_close(struct kr_cache *kres_db, knot_db_t * knot_db)
+{
+	free(knot_db);
+	kr_cache_close(kres_db);
+}
+
+int kr_gc_key_consistent(knot_db_val_t key)
+{
+	const uint8_t *kd = key.data;
+	ssize_t i;
+	/* CACHE_KEY_DEF */
+	if (key.len >= 2 && kd[0] == '\0') {
+		/* Beware: root zone is special and starts with
+		 *         a single \0 followed by type sign */
+		i = 1;
+	} else {
+		/* find the first double zero in the key */
+		for (i = 2; kd[i - 1] || kd[i - 2]; ++i) {
+			if (kr_fails_assert(i < key.len))
+				return kr_error(EINVAL);
+		}
+	}
+	// the next character can be used for classification
+	switch (kd[i]) {
+	case 'E':
+		(void)0; // C can't have a variable definition following a label
+		uint16_t type;
+		if (kr_fails_assert(i + 1 + sizeof(type) <= key.len))
+			return kr_error(EINVAL);
+		memcpy(&type, kd + i + 1, sizeof(type));
+		return type;
+	case '1':
+		return KNOT_RRTYPE_NSEC;
+	case '3':
+		return KNOT_RRTYPE_NSEC3;
+	case 'S': // the rtt_state entries are considered inconsistent, at least for now
+		return -1;
+	default:
+		kr_assert(!EINVAL);
+		return kr_error(EINVAL);
+	}
+}
+
+/// expects that key is consistent! CACHE_KEY_DEF
+static uint8_t entry_labels(knot_db_val_t * key, uint16_t rrtype)
+{
+	uint8_t lab = 0, *p = key->data;
+	while (*p != 0) {
+		while (*p++ != 0) {
+			if (p - (uint8_t *) key->data >= key->len) {
+				return 0;
+			}
+		}
+		lab++;
+	}
+	if (rrtype == KNOT_RRTYPE_NSEC3) {
+		// We don't know the number of labels so easily,
+		// but let's classify everything as directly
+		// below the zone apex (that's most common).
+		++lab;
+	}
+	return lab;
+}
+
+void debug_printbin(const char *str, unsigned int len)
+{
+	putchar('"');
+	for (int idx = 0; idx < len; idx++) {
+		char c = str[idx];
+		if (isprint(c))
+			putchar(c);
+		else
+			printf("`%02hhx`", c);
+	}
+	putchar('"');
+}
+
+/** Return one entry_h reference from a cache DB value.  NULL if not consistent/suitable. */
+static const struct entry_h *val2entry(const knot_db_val_t val, uint16_t ktype)
+{
+	if (ktype != KNOT_RRTYPE_NS)
+		return entry_h_consistent(val, ktype);
+	/* Otherwise we have a multi-purpose entry.
+	 * Well, for now we simply choose the most suitable entry;
+	 * the only realistic collision is DNAME in apex where we'll prefer NS. */
+	entry_list_t el;
+	if (entry_list_parse(val, el))
+		return NULL;
+	for (int i = ENTRY_APEX_NSECS_CNT; i < EL_LENGTH; ++i) {
+		if (el[i].len)
+			return entry_h_consistent(el[i], EL2RRTYPE(i));
+	}
+	/* Only NSEC* meta-data inside. */
+	return NULL;
+}
+
+int kr_gc_cache_iter(knot_db_t * knot_db, const  kr_cache_gc_cfg_t *cfg,
+			kr_gc_iter_callback callback, void *ctx)
+{
+	unsigned int counter_iter = 0;
+	unsigned int counter_gc_consistent = 0;
+	unsigned int counter_kr_consistent = 0;
+
+	knot_db_txn_t txn = { 0 };
+	knot_db_iter_t *it = NULL;
+	const knot_db_api_t *api = knot_db_lmdb_api();
+	gc_record_info_t info = { 0 };
+	int64_t now = time(NULL);
+
+	int ret = api->txn_begin(knot_db, &txn, KNOT_DB_RDONLY);
+	if (ret != KNOT_EOK) {
+		printf("Error starting DB transaction (%s).\n", knot_strerror(ret));
+		return ret;
+	}
+
+	it = api->iter_begin(&txn, KNOT_DB_NOOP); // _FIRST is split for easier debugging
+	if (it == NULL) {
+		printf("Error: failed to create an iterator.\n");
+		api->txn_abort(&txn);
+		return KNOT_ERROR;
+	}
+	it = api->iter_seek(it, NULL, KNOT_DB_FIRST);
+	if (it == NULL)
+		printf("Suspicious: completely empty LMDB at this moment?\n");
+
+	int txn_steps = 0;
+	while (it != NULL) {
+		knot_db_val_t key = { 0 }, val = { 0 };
+		ret = api->iter_key(it, &key);
+		if (ret == KNOT_EOK && key.len == 4 && memcmp("VERS", key.data, 4) == 0) {
+			/* skip DB metadata */
+			goto skip;
+		}
+		if (ret == KNOT_EOK) {
+			ret = api->iter_val(it, &val);
+		}
+		if (ret != KNOT_EOK) {
+			goto error;
+		}
+
+		info.entry_size = key.len + val.len;
+		info.valid = false;
+		const int entry_type = kr_gc_key_consistent(key);
+		const struct entry_h *entry = NULL;
+		if (entry_type >= 0) {
+			counter_gc_consistent++;
+			entry = val2entry(val, entry_type);
+		}
+		/* TODO: perhaps improve some details around here:
+		 *  - rtt_state entries are considered gc_inconsistent;
+		 *    therefore they'll be the first to get freed (see kr_gc_categorize())
+		 *  - xNAME have .rrtype NS
+		 *  - DNAME hidden on NS name will not be considered here
+		 *  - if zone has NSEC* meta-data but no NS, it will be seen
+		 *    here as kr_inconsistent */
+		if (entry != NULL) {
+			info.valid = true;
+			info.rrtype = entry_type;
+			info.expires_in = entry->time + entry->ttl - now;
+			info.no_labels = entry_labels(&key, entry_type);
+		}
+		counter_iter++;
+		counter_kr_consistent += info.valid;
+		if (VERBOSE_STATUS) {
+			if (!entry_type || !entry) {	// don't log fully consistent entries
+				printf
+				    ("GC %sconsistent, KR %sconsistent, size %zu, key len %zu: ",
+				     entry_type ? "" : "in", entry ? "" : "IN",
+				     (key.len + val.len), key.len);
+				debug_printbin(key.data, key.len);
+				printf("\n");
+			}
+		}
+		ret = callback(&key, &info, ctx);
+
+		if (ret != KNOT_EOK) {
+		error:
+			printf("Error iterating database (%s).\n",
+			       knot_strerror(ret));
+			api->iter_finish(it);
+			api->txn_abort(&txn);
+			return ret;
+		}
+
+	skip:	// Advance to the next GC item.
+		if (++txn_steps < cfg->ro_txn_items || !cfg->ro_txn_items/*unlimited*/) {
+			it = api->iter_next(it);
+		} else {
+			/* The transaction has been too long; let's reopen it. */
+			txn_steps = 0;
+			uint8_t key_storage[key.len];
+			memcpy(key_storage, key.data, key.len);
+			key.data = key_storage;
+
+			api->iter_finish(it);
+			api->txn_abort(&txn);
+
+			ret = api->txn_begin(knot_db, &txn, KNOT_DB_RDONLY);
+			if (ret != KNOT_EOK) {
+				printf("Error restarting DB transaction (%s).\n",
+					knot_strerror(ret));
+				return ret;
+			}
+			it = api->iter_begin(&txn, KNOT_DB_NOOP);
+			if (it == NULL) {
+				printf("Error: failed to create an iterator.\n");
+				api->txn_abort(&txn);
+				return KNOT_ERROR;
+			}
+			it = api->iter_seek(it, &key, KNOT_DB_GEQ);
+			// NULL here means we'we reached the end
+		}
+	}
+
+	api->txn_abort(&txn);
+
+	kr_log_debug(CACHE, "iterated %u items, gc consistent %u, kr consistent %u\n",
+		counter_iter, counter_gc_consistent, counter_kr_consistent);
+	return KNOT_EOK;
+}