X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fresolve%2Fresolved-dns-cache.c;fp=src%2Fresolve%2Fresolved-dns-cache.c;h=0000000000000000000000000000000000000000;hb=2dd57213e1114c1e034e52b7ff8eaeaee752d9f3;hp=33ca4d1a4549fc184b8a53c1e3efb4c291c7bac5;hpb=1dcca8e5fe679b21a7203d6e35d58aa7aa83bbe1;p=elogind.git

diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c
deleted file mode 100644
index 33ca4d1a4..000000000
--- a/src/resolve/resolved-dns-cache.c
+++ /dev/null
@@ -1,564 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
-  This file is part of systemd.
-
-  Copyright 2014 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include "resolved-dns-cache.h"
-#include "resolved-dns-packet.h"
-
-/* Never cache more than 1K entries */
-#define CACHE_MAX 1024
-
-/* We never keep any item longer than 10min in our cache */
-#define CACHE_TTL_MAX_USEC (10 * USEC_PER_MINUTE)
-
-typedef enum DnsCacheItemType DnsCacheItemType;
-typedef struct DnsCacheItem DnsCacheItem;
-
-enum DnsCacheItemType {
-        DNS_CACHE_POSITIVE,
-        DNS_CACHE_NODATA,
-        DNS_CACHE_NXDOMAIN,
-};
-
-struct DnsCacheItem {
-        DnsResourceKey *key;
-        DnsResourceRecord *rr;
-        usec_t until;
-        DnsCacheItemType type;
-        unsigned prioq_idx;
-        int owner_family;
-        union in_addr_union owner_address;
-        LIST_FIELDS(DnsCacheItem, by_key);
-};
-
-static void dns_cache_item_free(DnsCacheItem *i) {
-        if (!i)
-                return;
-
-        dns_resource_record_unref(i->rr);
-        dns_resource_key_unref(i->key);
-        free(i);
-}
-
-DEFINE_TRIVIAL_CLEANUP_FUNC(DnsCacheItem*, dns_cache_item_free);
-
-static void dns_cache_item_remove_and_free(DnsCache *c, DnsCacheItem *i) {
-        DnsCacheItem *first;
-
-        assert(c);
-
-        if (!i)
-                return;
-
-        first = hashmap_get(c->by_key, i->key);
-        LIST_REMOVE(by_key, first, i);
-
-        if (first)
-                assert_se(hashmap_replace(c->by_key, first->key, first) >= 0);
-        else
-                hashmap_remove(c->by_key, i->key);
-
-        prioq_remove(c->by_expiry, i, &i->prioq_idx);
-
-        dns_cache_item_free(i);
-}
-
-void dns_cache_flush(DnsCache *c) {
-        DnsCacheItem *i;
-
-        assert(c);
-
-        while ((i = hashmap_first(c->by_key)))
-                dns_cache_item_remove_and_free(c, i);
-
-        assert(hashmap_size(c->by_key) == 0);
-        assert(prioq_size(c->by_expiry) == 0);
-
-        hashmap_free(c->by_key);
-        c->by_key = NULL;
-
-        prioq_free(c->by_expiry);
-        c->by_expiry = NULL;
-}
-
-static void dns_cache_remove(DnsCache *c, DnsResourceKey *key) {
-        DnsCacheItem *i;
-
-        assert(c);
-        assert(key);
-
-        while ((i = hashmap_get(c->by_key, key)))
-                dns_cache_item_remove_and_free(c, i);
-}
-
-static void dns_cache_make_space(DnsCache *c, unsigned add) {
-        assert(c);
-
-        if (add <= 0)
-                return;
-
-        /* Makes space for n new entries. Note that we actually allow
-         * the cache to grow beyond CACHE_MAX, but only when we shall
-         * add more RRs to the cache than CACHE_MAX at once. In that
-         * case the cache will be emptied completely otherwise. */
-
-        for (;;) {
-                _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
-                DnsCacheItem *i;
-
-                if (prioq_size(c->by_expiry) <= 0)
-                        break;
-
-                if (prioq_size(c->by_expiry) + add < CACHE_MAX)
-                        break;
-
-                i = prioq_peek(c->by_expiry);
-                assert(i);
-
-                /* Take an extra reference to the key so that it
-                 * doesn't go away in the middle of the remove call */
-                key = dns_resource_key_ref(i->key);
-                dns_cache_remove(c, key);
-        }
-}
-
-void dns_cache_prune(DnsCache *c) {
-        usec_t t = 0;
-
-        assert(c);
-
-        /* Remove all entries that are past their TTL */
-
-        for (;;) {
-                _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
-                DnsCacheItem *i;
-
-                i = prioq_peek(c->by_expiry);
-                if (!i)
-                        break;
-
-                if (t <= 0)
-                        t = now(CLOCK_BOOTTIME);
-
-                if (i->until > t)
-                        break;
-
-                /* Take an extra reference to the key so that it
-                 * doesn't go away in the middle of the remove call */
-                key = dns_resource_key_ref(i->key);
-                dns_cache_remove(c, key);
-        }
-}
-
-static int dns_cache_item_prioq_compare_func(const void *a, const void *b) {
-        const DnsCacheItem *x = a, *y = b;
-
-        if (x->until < y->until)
-                return -1;
-        if (x->until > y->until)
-                return 1;
-        return 0;
-}
-
-static int dns_cache_init(DnsCache *c) {
-        int r;
-
-        assert(c);
-
-        r = prioq_ensure_allocated(&c->by_expiry, dns_cache_item_prioq_compare_func);
-        if (r < 0)
-                return r;
-
-        r = hashmap_ensure_allocated(&c->by_key, &dns_resource_key_hash_ops);
-        if (r < 0)
-                return r;
-
-        return r;
-}
-
-static int dns_cache_link_item(DnsCache *c, DnsCacheItem *i) {
-        DnsCacheItem *first;
-        int r;
-
-        assert(c);
-        assert(i);
-
-        r = prioq_put(c->by_expiry, i, &i->prioq_idx);
-        if (r < 0)
-                return r;
-
-        first = hashmap_get(c->by_key, i->key);
-        if (first) {
-                LIST_PREPEND(by_key, first, i);
-                assert_se(hashmap_replace(c->by_key, first->key, first) >= 0);
-        } else {
-                r = hashmap_put(c->by_key, i->key, i);
-                if (r < 0) {
-                        prioq_remove(c->by_expiry, i, &i->prioq_idx);
-                        return r;
-                }
-        }
-
-        return 0;
-}
-
-static DnsCacheItem* dns_cache_get(DnsCache *c, DnsResourceRecord *rr) {
-        DnsCacheItem *i;
-
-        assert(c);
-        assert(rr);
-
-        LIST_FOREACH(by_key, i, hashmap_get(c->by_key, rr->key))
-                if (i->rr && dns_resource_record_equal(i->rr, rr) > 0)
-                        return i;
-
-        return NULL;
-}
-
-static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsResourceRecord *rr, usec_t timestamp) {
-        assert(c);
-        assert(i);
-        assert(rr);
-
-        i->type = DNS_CACHE_POSITIVE;
-
-        if (!i->by_key_prev) {
-                /* We are the first item in the list, we need to
-                 * update the key used in the hashmap */
-
-                assert_se(hashmap_replace(c->by_key, rr->key, i) >= 0);
-        }
-
-        dns_resource_record_ref(rr);
-        dns_resource_record_unref(i->rr);
-        i->rr = rr;
-
-        dns_resource_key_unref(i->key);
-        i->key = dns_resource_key_ref(rr->key);
-
-        i->until = timestamp + MIN(rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC);
-
-        prioq_reshuffle(c->by_expiry, i, &i->prioq_idx);
-}
-
-static int dns_cache_put_positive(
-                DnsCache *c,
-                DnsResourceRecord *rr,
-                usec_t timestamp,
-                int owner_family,
-                const union in_addr_union *owner_address) {
-
-        _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL;
-        DnsCacheItem *existing;
-        int r;
-
-        assert(c);
-        assert(rr);
-        assert(owner_address);
-
-        /* New TTL is 0? Delete the entry... */
-        if (rr->ttl <= 0) {
-                dns_cache_remove(c, rr->key);
-                return 0;
-        }
-
-        if (rr->key->class == DNS_CLASS_ANY)
-                return 0;
-        if (rr->key->type == DNS_TYPE_ANY)
-                return 0;
-
-        /* Entry exists already? Update TTL and timestamp */
-        existing = dns_cache_get(c, rr);
-        if (existing) {
-                dns_cache_item_update_positive(c, existing, rr, timestamp);
-                return 0;
-        }
-
-        /* Otherwise, add the new RR */
-        r = dns_cache_init(c);
-        if (r < 0)
-                return r;
-
-        dns_cache_make_space(c, 1);
-
-        i = new0(DnsCacheItem, 1);
-        if (!i)
-                return -ENOMEM;
-
-        i->type = DNS_CACHE_POSITIVE;
-        i->key = dns_resource_key_ref(rr->key);
-        i->rr = dns_resource_record_ref(rr);
-        i->until = timestamp + MIN(i->rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC);
-        i->prioq_idx = PRIOQ_IDX_NULL;
-        i->owner_family = owner_family;
-        i->owner_address = *owner_address;
-
-        r = dns_cache_link_item(c, i);
-        if (r < 0)
-                return r;
-
-        i = NULL;
-        return 0;
-}
-
-static int dns_cache_put_negative(
-                DnsCache *c,
-                DnsResourceKey *key,
-                int rcode,
-                usec_t timestamp,
-                uint32_t soa_ttl,
-                int owner_family,
-                const union in_addr_union *owner_address) {
-
-        _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL;
-        int r;
-
-        assert(c);
-        assert(key);
-        assert(owner_address);
-
-        dns_cache_remove(c, key);
-
-        if (key->class == DNS_CLASS_ANY)
-                return 0;
-        if (key->type == DNS_TYPE_ANY)
-                return 0;
-        if (soa_ttl <= 0)
-                return 0;
-
-        if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN))
-                return 0;
-
-        r = dns_cache_init(c);
-        if (r < 0)
-                return r;
-
-        dns_cache_make_space(c, 1);
-
-        i = new0(DnsCacheItem, 1);
-        if (!i)
-                return -ENOMEM;
-
-        i->type = rcode == DNS_RCODE_SUCCESS ? DNS_CACHE_NODATA : DNS_CACHE_NXDOMAIN;
-        i->key = dns_resource_key_ref(key);
-        i->until = timestamp + MIN(soa_ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC);
-        i->prioq_idx = PRIOQ_IDX_NULL;
-        i->owner_family = owner_family;
-        i->owner_address = *owner_address;
-
-        r = dns_cache_link_item(c, i);
-        if (r < 0)
-                return r;
-
-        i = NULL;
-        return 0;
-}
-
-int dns_cache_put(
-                DnsCache *c,
-                DnsQuestion *q,
-                int rcode,
-                DnsAnswer *answer,
-                unsigned max_rrs,
-                usec_t timestamp,
-                int owner_family,
-                const union in_addr_union *owner_address) {
-
-        unsigned i;
-        int r;
-
-        assert(c);
-        assert(q);
-
-        /* First, delete all matching old RRs, so that we only keep
-         * complete by_key in place. */
-        for (i = 0; i < q->n_keys; i++)
-                dns_cache_remove(c, q->keys[i]);
-
-        if (!answer)
-                return 0;
-
-        for (i = 0; i < answer->n_rrs; i++)
-                dns_cache_remove(c, answer->rrs[i]->key);
-
-        /* We only care for positive replies and NXDOMAINs, on all
-         * other replies we will simply flush the respective entries,
-         * and that's it */
-
-        if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN))
-                return 0;
-
-        /* Make some space for our new entries */
-        dns_cache_make_space(c, answer->n_rrs + q->n_keys);
-
-        if (timestamp <= 0)
-                timestamp = now(CLOCK_BOOTTIME);
-
-        /* Second, add in positive entries for all contained RRs */
-        for (i = 0; i < MIN(max_rrs, answer->n_rrs); i++) {
-                r = dns_cache_put_positive(c, answer->rrs[i], timestamp, owner_family, owner_address);
-                if (r < 0)
-                        goto fail;
-        }
-
-        /* Third, add in negative entries for all keys with no RR */
-        for (i = 0; i < q->n_keys; i++) {
-                DnsResourceRecord *soa = NULL;
-
-                r = dns_answer_contains(answer, q->keys[i]);
-                if (r < 0)
-                        goto fail;
-                if (r > 0)
-                        continue;
-
-                r = dns_answer_find_soa(answer, q->keys[i], &soa);
-                if (r < 0)
-                        goto fail;
-                if (r == 0)
-                        continue;
-
-                r = dns_cache_put_negative(c, q->keys[i], rcode, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address);
-                if (r < 0)
-                        goto fail;
-        }
-
-        return 0;
-
-fail:
-        /* Adding all RRs failed. Let's clean up what we already
-         * added, just in case */
-
-        for (i = 0; i < q->n_keys; i++)
-                dns_cache_remove(c, q->keys[i]);
-        for (i = 0; i < answer->n_rrs; i++)
-                dns_cache_remove(c, answer->rrs[i]->key);
-
-        return r;
-}
-
-int dns_cache_lookup(DnsCache *c, DnsQuestion *q, int *rcode, DnsAnswer **ret) {
-        _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
-        unsigned i, n = 0;
-        int r;
-        bool nxdomain = false;
-
-        assert(c);
-        assert(q);
-        assert(rcode);
-        assert(ret);
-
-        if (q->n_keys <= 0) {
-                *ret = NULL;
-                *rcode = 0;
-                return 0;
-        }
-
-        for (i = 0; i < q->n_keys; i++) {
-                DnsCacheItem *j;
-
-                if (q->keys[i]->type == DNS_TYPE_ANY ||
-                    q->keys[i]->class == DNS_CLASS_ANY) {
-                        /* If we have ANY lookups we simply refresh */
-                        *ret = NULL;
-                        *rcode = 0;
-                        return 0;
-                }
-
-                j = hashmap_get(c->by_key, q->keys[i]);
-                if (!j) {
-                        /* If one question cannot be answered we need to refresh */
-                        *ret = NULL;
-                        *rcode = 0;
-                        return 0;
-                }
-
-                LIST_FOREACH(by_key, j, j) {
-                        if (j->rr)
-                                n++;
-                        else if (j->type == DNS_CACHE_NXDOMAIN)
-                                nxdomain = true;
-                }
-        }
-
-        if (n <= 0) {
-                *ret = NULL;
-                *rcode = nxdomain ? DNS_RCODE_NXDOMAIN : DNS_RCODE_SUCCESS;
-                return 1;
-        }
-
-        answer = dns_answer_new(n);
-        if (!answer)
-                return -ENOMEM;
-
-        for (i = 0; i < q->n_keys; i++) {
-                DnsCacheItem *j;
-
-                j = hashmap_get(c->by_key, q->keys[i]);
-                LIST_FOREACH(by_key, j, j) {
-                        if (j->rr) {
-                                r = dns_answer_add(answer, j->rr);
-                                if (r < 0)
-                                        return r;
-                        }
-                }
-        }
-
-        *ret = answer;
-        *rcode = DNS_RCODE_SUCCESS;
-        answer = NULL;
-
-        return n;
-}
-
-int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address) {
-        DnsCacheItem *i, *first;
-        bool same_owner = true;
-
-        assert(cache);
-        assert(rr);
-
-        dns_cache_prune(cache);
-
-        /* See if there's a cache entry for the same key. If there
-         * isn't there's no conflict */
-        first = hashmap_get(cache->by_key, rr->key);
-        if (!first)
-                return 0;
-
-        /* See if the RR key is owned by the same owner, if so, there
-         * isn't a conflict either */
-        LIST_FOREACH(by_key, i, first) {
-                if (i->owner_family != owner_family ||
-                    !in_addr_equal(owner_family, &i->owner_address, owner_address)) {
-                        same_owner = false;
-                        break;
-                }
-        }
-        if (same_owner)
-                return 0;
-
-        /* See if there's the exact same RR in the cache. If yes, then
-         * there's no conflict. */
-        if (dns_cache_get(cache, rr))
-                return 0;
-
-        /* There's a conflict */
-        return 1;
-}