X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=src%2Fresolve%2Fresolved-dns-answer.c;h=5355303bd33aca9fa91ede7d3b14b4732458822c;hb=a5784c498598348354543b23b13ee8639a8b9e35;hp=93e51fc2488662b9ddb471b3f3583732029caf8f;hpb=af93291cc4cbd2fe2fb4af7d3c56138fb39f31dc;p=thirdparty%2Fsystemd.git

diff --git a/src/resolve/resolved-dns-answer.c b/src/resolve/resolved-dns-answer.c
index 93e51fc2488..5355303bd33 100644
--- a/src/resolve/resolved-dns-answer.c
+++ b/src/resolve/resolved-dns-answer.c
@@ -19,15 +19,16 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include "alloc-util.h"
+#include "dns-domain.h"
 #include "resolved-dns-answer.h"
-#include "resolved-dns-domain.h"
+#include "resolved-dns-dnssec.h"
+#include "string-util.h"
 
 DnsAnswer *dns_answer_new(unsigned n) {
         DnsAnswer *a;
 
-        assert(n > 0);
-
-        a = malloc0(offsetof(DnsAnswer, rrs) + sizeof(DnsResourceRecord*) * n);
+        a = malloc0(offsetof(DnsAnswer, items) + sizeof(DnsAnswerItem) * n);
         if (!a)
                 return NULL;
 
@@ -46,6 +47,18 @@ DnsAnswer *dns_answer_ref(DnsAnswer *a) {
         return a;
 }
 
+static void dns_answer_flush(DnsAnswer *a) {
+        DnsResourceRecord *rr;
+
+        if (!a)
+                return;
+
+        DNS_ANSWER_FOREACH(rr, a)
+                dns_resource_record_unref(rr);
+
+        a->n_rrs = 0;
+}
+
 DnsAnswer *dns_answer_unref(DnsAnswer *a) {
         if (!a)
                 return NULL;
@@ -53,11 +66,7 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a) {
         assert(a->n_ref > 0);
 
         if (a->n_ref == 1) {
-                unsigned i;
-
-                for (i = 0; i < a->n_rrs; i++)
-                        dns_resource_record_unref(a->rrs[i]);
-
+                dns_answer_flush(a);
                 free(a);
         } else
                 a->n_ref--;
@@ -65,47 +74,133 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a) {
         return NULL;
 }
 
-int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr) {
+static int dns_answer_add_raw(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) {
+        assert(rr);
+
+        if (!a)
+                return -ENOSPC;
+
+        if (a->n_rrs >= a->n_allocated)
+                return -ENOSPC;
+
+        a->items[a->n_rrs].rr = dns_resource_record_ref(rr);
+        a->items[a->n_rrs].ifindex = ifindex;
+        a->n_rrs++;
+
+        return 1;
+}
+
+static int dns_answer_add_raw_all(DnsAnswer *a, DnsAnswer *source) {
+        DnsResourceRecord *rr;
+        int ifindex, r;
+
+        DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, source) {
+                r = dns_answer_add_raw(a, rr, ifindex);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) {
         unsigned i;
         int r;
 
-        assert(a);
         assert(rr);
 
+        if (!a)
+                return -ENOSPC;
+        if (a->n_ref > 1)
+                return -EBUSY;
+
         for (i = 0; i < a->n_rrs; i++) {
-                r = dns_resource_record_equal(a->rrs[i], rr);
+                if (a->items[i].ifindex != ifindex)
+                        continue;
+
+                r = dns_resource_record_equal(a->items[i].rr, rr);
                 if (r < 0)
                         return r;
                 if (r > 0) {
                         /* Entry already exists, keep the entry with
                          * the higher RR, or the one with TTL 0 */
 
-                        if (rr->ttl == 0 || (rr->ttl > a->rrs[i]->ttl && a->rrs[i]->ttl != 0)) {
+                        if (rr->ttl == 0 || (rr->ttl > a->items[i].rr->ttl && a->items[i].rr->ttl != 0)) {
                                 dns_resource_record_ref(rr);
-                                dns_resource_record_unref(a->rrs[i]);
-                                a->rrs[i] = rr;
+                                dns_resource_record_unref(a->items[i].rr);
+                                a->items[i].rr = rr;
                         }
 
                         return 0;
                 }
         }
 
-        if (a->n_rrs >= a->n_allocated)
-                return -ENOSPC;
+        return dns_answer_add_raw(a, rr, ifindex);
+}
 
-        a->rrs[a->n_rrs++] = dns_resource_record_ref(rr);
-        return 1;
+static int dns_answer_add_all(DnsAnswer *a, DnsAnswer *b) {
+        DnsResourceRecord *rr;
+        int ifindex, r;
+
+        DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, b) {
+                r = dns_answer_add(a, rr, ifindex);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
 }
 
-int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) {
-        unsigned i;
+int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex) {
         int r;
 
         assert(a);
+        assert(rr);
+
+        r = dns_answer_reserve_or_clone(a, 1);
+        if (r < 0)
+                return r;
+
+        return dns_answer_add(*a, rr, ifindex);
+}
+
+int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl) {
+        _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *soa = NULL;
+
+        soa = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_SOA, name);
+        if (!soa)
+                return -ENOMEM;
+
+        soa->ttl = ttl;
+
+        soa->soa.mname = strdup(name);
+        if (!soa->soa.mname)
+                return -ENOMEM;
+
+        soa->soa.rname = strappend("root.", name);
+        if (!soa->soa.rname)
+                return -ENOMEM;
+
+        soa->soa.serial = 1;
+        soa->soa.refresh = 1;
+        soa->soa.retry = 1;
+        soa->soa.expire = 1;
+        soa->soa.minimum = ttl;
+
+        return dns_answer_add(a, soa, 0);
+}
+
+int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key) {
+        DnsResourceRecord *i;
+        int r;
+
         assert(key);
 
-        for (i = 0; i < a->n_rrs; i++) {
-                r = dns_resource_key_match_rr(key, a->rrs[i]);
+        if (!a)
+                return 0;
+
+        DNS_ANSWER_FOREACH(i, a) {
+                r = dns_resource_key_match_rr(key, i, NULL);
                 if (r < 0)
                         return r;
                 if (r > 0)
@@ -115,23 +210,70 @@ int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) {
         return 0;
 }
 
-int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) {
-        unsigned i;
+int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr) {
+        DnsResourceRecord *i;
+        int r;
+
+        assert(rr);
+
+        DNS_ANSWER_FOREACH(i, a) {
+                r = dns_resource_record_equal(i, rr);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        return 1;
+        }
+
+        return 0;
+}
+
+int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret) {
+        DnsResourceRecord *rr;
+        int r;
 
-        assert(a);
         assert(key);
-        assert(ret);
 
-        for (i = 0; i < a->n_rrs; i++) {
+        if (!a)
+                return 0;
 
-                if (a->rrs[i]->key->class != DNS_CLASS_IN)
-                        continue;
+        /* For a SOA record we can never find a matching SOA record */
+        if (key->type == DNS_TYPE_SOA)
+                return 0;
 
-                if (a->rrs[i]->key->type != DNS_TYPE_SOA)
-                        continue;
+        DNS_ANSWER_FOREACH(rr, a) {
+                r = dns_resource_key_match_soa(key, rr->key);
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        if (ret)
+                                *ret = rr;
+                        return 1;
+                }
+        }
+
+        return 0;
+}
+
+int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret) {
+        DnsResourceRecord *rr;
+        int r;
 
-                if (dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(a->rrs[i]->key))) {
-                        *ret = a->rrs[i];
+        assert(key);
+
+        if (!a)
+                return 0;
+
+        /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */
+        if (key->type == DNS_TYPE_CNAME || key->type == DNS_TYPE_DNAME)
+                return 0;
+
+        DNS_ANSWER_FOREACH(rr, a) {
+                r = dns_resource_key_match_cname_or_dname(key, rr->key, NULL);
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        if (ret)
+                                *ret = rr;
                         return 1;
                 }
         }
@@ -139,47 +281,177 @@ int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **r
         return 0;
 }
 
-DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b) {
-        _cleanup_(dns_answer_unrefp) DnsAnswer *ret = NULL;
-        DnsAnswer *k;
+int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret) {
+        _cleanup_(dns_answer_unrefp) DnsAnswer *k = NULL;
+        int r;
+
+        assert(ret);
+
+        if (dns_answer_size(a) <= 0) {
+                *ret = dns_answer_ref(b);
+                return 0;
+        }
+
+        if (dns_answer_size(b) <= 0) {
+                *ret = dns_answer_ref(a);
+                return 0;
+        }
+
+        k = dns_answer_new(a->n_rrs + b->n_rrs);
+        if (!k)
+                return -ENOMEM;
+
+        r = dns_answer_add_raw_all(k, a);
+        if (r < 0)
+                return r;
+
+        r = dns_answer_add_all(k, b);
+        if (r < 0)
+                return r;
+
+        *ret = k;
+        k = NULL;
+
+        return 0;
+}
+
+int dns_answer_extend(DnsAnswer **a, DnsAnswer *b) {
+        DnsAnswer *merged;
+        int r;
+
+        assert(a);
+
+        r = dns_answer_merge(*a, b, &merged);
+        if (r < 0)
+                return r;
+
+        dns_answer_unref(*a);
+        *a = merged;
+
+        return 0;
+}
+
+int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key) {
+        bool found = false, other = false;
+        DnsResourceRecord *rr;
         unsigned i;
         int r;
 
-        if (a && (!b || b->n_rrs <= 0))
-                return dns_answer_ref(a);
-        if ((!a || a->n_rrs <= 0) && b)
-                return dns_answer_ref(b);
+        assert(a);
+        assert(key);
 
-        ret = dns_answer_new((a ? a->n_rrs : 0) + (b ? b->n_rrs : 0));
-        if (!ret)
-                return NULL;
+        /* Remove all entries matching the specified key from *a */
 
-        if (a) {
-                for (i = 0; i < a->n_rrs; i++) {
-                        r = dns_answer_add(ret, a->rrs[i]);
-                        if (r < 0)
-                                return NULL;
-                }
+        DNS_ANSWER_FOREACH(rr, *a) {
+                r = dns_resource_key_equal(rr->key, key);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        found = true;
+                else
+                        other = true;
+
+                if (found && other)
+                        break;
         }
 
-        if (b) {
-                for (i = 0; i < b->n_rrs; i++) {
-                        r = dns_answer_add(ret, b->rrs[i]);
+        if (!found)
+                return 0;
+
+        if (!other) {
+                *a = dns_answer_unref(*a); /* Return NULL for the empty answer */
+                return 1;
+        }
+
+        if ((*a)->n_ref > 1) {
+                _cleanup_(dns_answer_unrefp) DnsAnswer *copy = NULL;
+                int ifindex;
+
+                copy = dns_answer_new((*a)->n_rrs);
+                if (!copy)
+                        return -ENOMEM;
+
+                DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, *a) {
+                        r = dns_resource_key_equal(rr->key, key);
+                        if (r < 0)
+                                return r;
+                        if (r > 0)
+                                continue;
+
+                        r = dns_answer_add_raw(copy, rr, ifindex);
                         if (r < 0)
-                                return NULL;
+                                return r;
                 }
+
+                dns_answer_unref(*a);
+                *a = copy;
+                copy = NULL;
+
+                return 1;
         }
 
-        k = ret;
-        ret = NULL;
+        /* Only a single reference, edit in-place */
+
+        i = 0;
+        for (;;) {
+                if (i >= (*a)->n_rrs)
+                        break;
+
+                r = dns_resource_key_equal((*a)->items[i].rr->key, key);
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        /* Kill this entry */
 
-        return k;
+                        dns_resource_record_unref((*a)->items[i].rr);
+                        memmove((*a)->items + i, (*a)->items + i + 1, sizeof(DnsAnswerItem) * ((*a)->n_rrs - i - 1));
+                        (*a)->n_rrs --;
+                        continue;
+
+                } else
+                        /* Keep this entry */
+                        i++;
+        }
+
+        return 1;
+}
+
+int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key) {
+        DnsResourceRecord *rr_source;
+        int ifindex_source, r;
+
+        assert(a);
+        assert(key);
+
+        /* Copy all RRs matching the specified key from source into *a */
+
+        DNS_ANSWER_FOREACH_IFINDEX(rr_source, ifindex_source, source) {
+
+                r = dns_resource_key_equal(rr_source->key, key);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                /* Make space for at least one entry */
+                r = dns_answer_reserve_or_clone(a, 1);
+                if (r < 0)
+                        return r;
+
+                r = dns_answer_add(*a, rr_source, ifindex_source);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
 }
 
 void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) {
-        DnsResourceRecord **rrs;
+        DnsAnswerItem *items;
         unsigned i, start, end;
-        assert(a);
+
+        if (!a)
+                return;
 
         if (a->n_rrs <= 1)
                 return;
@@ -190,19 +462,89 @@ void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) {
         /* RFC 4795, Section 2.6 suggests we should order entries
          * depending on whether the sender is a link-local address. */
 
-        rrs = newa(DnsResourceRecord*, a->n_rrs);
+        items = newa(DnsAnswerItem, a->n_rrs);
         for (i = 0; i < a->n_rrs; i++) {
 
-                if (a->rrs[i]->key->class == DNS_CLASS_IN &&
-                    ((a->rrs[i]->key->type == DNS_TYPE_A && in_addr_is_link_local(AF_INET, (union in_addr_union*) &a->rrs[i]->a.in_addr) != prefer_link_local) ||
-                     (a->rrs[i]->key->type == DNS_TYPE_AAAA && in_addr_is_link_local(AF_INET6, (union in_addr_union*) &a->rrs[i]->aaaa.in6_addr) != prefer_link_local)))
+                if (a->items[i].rr->key->class == DNS_CLASS_IN &&
+                    ((a->items[i].rr->key->type == DNS_TYPE_A && in_addr_is_link_local(AF_INET, (union in_addr_union*) &a->items[i].rr->a.in_addr) != prefer_link_local) ||
+                     (a->items[i].rr->key->type == DNS_TYPE_AAAA && in_addr_is_link_local(AF_INET6, (union in_addr_union*) &a->items[i].rr->aaaa.in6_addr) != prefer_link_local)))
                         /* Order address records that are are not preferred to the end of the array */
-                        rrs[end--] = a->rrs[i];
+                        items[end--] = a->items[i];
                 else
                         /* Order all other records to the beginning of the array */
-                        rrs[start++] = a->rrs[i];
+                        items[start++] = a->items[i];
         }
 
         assert(start == end+1);
-        memcpy(a->rrs, rrs, sizeof(DnsResourceRecord*) * a->n_rrs);
+        memcpy(a->items, items, sizeof(DnsAnswerItem) * a->n_rrs);
+}
+
+int dns_answer_reserve(DnsAnswer **a, unsigned n_free) {
+        DnsAnswer *n;
+
+        assert(a);
+
+        if (n_free <= 0)
+                return 0;
+
+        if (*a) {
+                unsigned ns;
+
+                if ((*a)->n_ref > 1)
+                        return -EBUSY;
+
+                ns = (*a)->n_rrs + n_free;
+
+                if ((*a)->n_allocated >= ns)
+                        return 0;
+
+                /* Allocate more than we need */
+                ns *= 2;
+
+                n = realloc(*a, offsetof(DnsAnswer, items) + sizeof(DnsAnswerItem) * ns);
+                if (!n)
+                        return -ENOMEM;
+
+                n->n_allocated = ns;
+        } else {
+                n = dns_answer_new(n_free);
+                if (!n)
+                        return -ENOMEM;
+        }
+
+        *a = n;
+        return 0;
+}
+
+int dns_answer_reserve_or_clone(DnsAnswer **a, unsigned n_free) {
+        _cleanup_(dns_answer_unrefp) DnsAnswer *n = NULL;
+        int r;
+
+        assert(a);
+
+        /* Tries to extend the DnsAnswer object. And if that's not
+         * possibly, since we are not the sole owner, then allocate a
+         * new, appropriately sized one. Either way, after this call
+         * the object will only have a single reference, and has room
+         * for at least the specified number of RRs. */
+
+        r = dns_answer_reserve(a, n_free);
+        if (r != -EBUSY)
+                return r;
+
+        assert(*a);
+
+        n = dns_answer_new(((*a)->n_rrs + n_free) * 2);
+        if (!n)
+                return -ENOMEM;
+
+        r = dns_answer_add_raw_all(n, *a);
+        if (r < 0)
+                return r;
+
+        dns_answer_unref(*a);
+        *a = n;
+        n = NULL;
+
+        return 0;
 }