Adding upstream version 247.3.upstream/247.3upstream

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

1 files changed, 447 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-question.c b/src/resolve/resolved-dns-question.c
new file mode 100644
index 0000000..0471708
--- /dev/null
+++ b/src/resolve/resolved-dns-question.c
@@ -0,0 +1,447 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "dns-domain.h"
+#include "dns-type.h"
+#include "resolved-dns-question.h"
+
+DnsQuestion *dns_question_new(size_t n) {
+        DnsQuestion *q;
+
+        if (n > UINT16_MAX) /* We can only place 64K key in an question section at max */
+                n = UINT16_MAX;
+
+        q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n);
+        if (!q)
+                return NULL;
+
+        q->n_ref = 1;
+        q->n_allocated = n;
+
+        return q;
+}
+
+static DnsQuestion *dns_question_free(DnsQuestion *q) {
+        size_t i;
+
+        assert(q);
+
+        for (i = 0; i < q->n_keys; i++)
+                dns_resource_key_unref(q->keys[i]);
+        return mfree(q);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(DnsQuestion, dns_question, dns_question_free);
+
+int dns_question_add_raw(DnsQuestion *q, DnsResourceKey *key) {
+        /* Insert without checking for duplicates. */
+
+        assert(key);
+        assert(q);
+
+        if (q->n_keys >= q->n_allocated)
+                return -ENOSPC;
+
+        q->keys[q->n_keys++] = dns_resource_key_ref(key);
+        return 0;
+}
+
+int dns_question_add(DnsQuestion *q, DnsResourceKey *key) {
+        int r;
+
+        assert(key);
+
+        if (!q)
+                return -ENOSPC;
+
+        for (size_t i = 0; i < q->n_keys; i++) {
+                r = dns_resource_key_equal(q->keys[i], key);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        return 0;
+        }
+
+        return dns_question_add_raw(q, key);
+}
+
+int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) {
+        size_t i;
+        int r;
+
+        assert(rr);
+
+        if (!q)
+                return 0;
+
+        for (i = 0; i < q->n_keys; i++) {
+                r = dns_resource_key_match_rr(q->keys[i], rr, search_domain);
+                if (r != 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) {
+        size_t i;
+        int r;
+
+        assert(rr);
+
+        if (!q)
+                return 0;
+
+        if (!IN_SET(rr->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME))
+                return 0;
+
+        for (i = 0; i < q->n_keys; i++) {
+                /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */
+                if (!dns_type_may_redirect(q->keys[i]->type))
+                        return 0;
+
+                r = dns_resource_key_match_cname_or_dname(q->keys[i], rr->key, search_domain);
+                if (r != 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int dns_question_is_valid_for_query(DnsQuestion *q) {
+        const char *name;
+        size_t i;
+        int r;
+
+        if (!q)
+                return 0;
+
+        if (q->n_keys <= 0)
+                return 0;
+
+        if (q->n_keys > 65535)
+                return 0;
+
+        name = dns_resource_key_name(q->keys[0]);
+        if (!name)
+                return 0;
+
+        /* Check that all keys in this question bear the same name */
+        for (i = 0; i < q->n_keys; i++) {
+                assert(q->keys[i]);
+
+                if (i > 0) {
+                        r = dns_name_equal(dns_resource_key_name(q->keys[i]), name);
+                        if (r <= 0)
+                                return r;
+                }
+
+                if (!dns_type_is_valid_query(q->keys[i]->type))
+                        return 0;
+        }
+
+        return 1;
+}
+
+int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k) {
+        size_t j;
+        int r;
+
+        assert(k);
+
+        if (!a)
+                return 0;
+
+        for (j = 0; j < a->n_keys; j++) {
+                r = dns_resource_key_equal(a->keys[j], k);
+                if (r != 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) {
+        size_t j;
+        int r;
+
+        if (a == b)
+                return 1;
+
+        if (!a)
+                return !b || b->n_keys == 0;
+        if (!b)
+                return a->n_keys == 0;
+
+        /* Checks if all keys in a are also contained b, and vice versa */
+
+        for (j = 0; j < a->n_keys; j++) {
+                r = dns_question_contains(b, a->keys[j]);
+                if (r <= 0)
+                        return r;
+        }
+
+        for (j = 0; j < b->n_keys; j++) {
+                r = dns_question_contains(a, b->keys[j]);
+                if (r <= 0)
+                        return r;
+        }
+
+        return 1;
+}
+
+int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) {
+        _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL;
+        DnsResourceKey *key;
+        bool same = true;
+        int r;
+
+        assert(cname);
+        assert(ret);
+        assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME));
+
+        if (dns_question_size(q) <= 0) {
+                *ret = NULL;
+                return 0;
+        }
+
+        DNS_QUESTION_FOREACH(key, q) {
+                _cleanup_free_ char *destination = NULL;
+                const char *d;
+
+                if (cname->key->type == DNS_TYPE_CNAME)
+                        d = cname->cname.name;
+                else {
+                        r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination);
+                        if (r < 0)
+                                return r;
+                        if (r == 0)
+                                continue;
+
+                        d = destination;
+                }
+
+                r = dns_name_equal(dns_resource_key_name(key), d);
+                if (r < 0)
+                        return r;
+
+                if (r == 0) {
+                        same = false;
+                        break;
+                }
+        }
+
+        /* Fully the same, indicate we didn't do a thing */
+        if (same) {
+                *ret = NULL;
+                return 0;
+        }
+
+        n = dns_question_new(q->n_keys);
+        if (!n)
+                return -ENOMEM;
+
+        /* Create a new question, and patch in the new name */
+        DNS_QUESTION_FOREACH(key, q) {
+                _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL;
+
+                k = dns_resource_key_new_redirect(key, cname);
+                if (!k)
+                        return -ENOMEM;
+
+                r = dns_question_add(n, k);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(n);
+
+        return 1;
+}
+
+const char *dns_question_first_name(DnsQuestion *q) {
+
+        if (!q)
+                return NULL;
+
+        if (q->n_keys < 1)
+                return NULL;
+
+        return dns_resource_key_name(q->keys[0]);
+}
+
+int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna) {
+        _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
+        _cleanup_free_ char *buf = NULL;
+        int r;
+
+        assert(ret);
+        assert(name);
+
+        if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
+                return -EAFNOSUPPORT;
+
+        if (convert_idna) {
+                r = dns_name_apply_idna(name, &buf);
+                if (r < 0)
+                        return r;
+                if (r > 0 && !streq(name, buf))
+                        name = buf;
+                else
+                        /* We did not manage to create convert the idna name, or it's
+                         * the same as the original name. We assume the caller already
+                         * created an unconverted question, so let's not repeat work
+                         * unnecessarily. */
+                        return -EALREADY;
+        }
+
+        q = dns_question_new(family == AF_UNSPEC ? 2 : 1);
+        if (!q)
+                return -ENOMEM;
+
+        if (family != AF_INET6) {
+                _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
+
+                key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name);
+                if (!key)
+                        return -ENOMEM;
+
+                r = dns_question_add(q, key);
+                if (r < 0)
+                        return r;
+        }
+
+        if (family != AF_INET) {
+                _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
+
+                key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name);
+                if (!key)
+                        return -ENOMEM;
+
+                r = dns_question_add(q, key);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(q);
+
+        return 0;
+}
+
+int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) {
+        _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
+        _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
+        _cleanup_free_ char *reverse = NULL;
+        int r;
+
+        assert(ret);
+        assert(a);
+
+        if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
+                return -EAFNOSUPPORT;
+
+        r = dns_name_reverse(family, a, &reverse);
+        if (r < 0)
+                return r;
+
+        q = dns_question_new(1);
+        if (!q)
+                return -ENOMEM;
+
+        key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse);
+        if (!key)
+                return -ENOMEM;
+
+        reverse = NULL;
+
+        r = dns_question_add(q, key);
+        if (r < 0)
+                return r;
+
+        *ret = TAKE_PTR(q);
+
+        return 0;
+}
+
+int dns_question_new_service(
+                DnsQuestion **ret,
+                const char *service,
+                const char *type,
+                const char *domain,
+                bool with_txt,
+                bool convert_idna) {
+
+        _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
+        _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
+        _cleanup_free_ char *buf = NULL, *joined = NULL;
+        const char *name;
+        int r;
+
+        assert(ret);
+
+        /* We support three modes of invocation:
+         *
+         * 1. Only a domain is specified, in which case we assume a properly encoded SRV RR name, including service
+         *    type and possibly a service name. If specified in this way we assume it's already IDNA converted if
+         *    that's necessary.
+         *
+         * 2. Both service type and a domain specified, in which case a normal SRV RR is assumed, without a DNS-SD
+         *    style prefix. In this case we'll IDNA convert the domain, if that's requested.
+         *
+         * 3. All three of service name, type and domain are specified, in which case a DNS-SD service is put
+         *    together. The service name is never IDNA converted, and the domain is if requested.
+         *
+         * It's not supported to specify a service name without a type, or no domain name.
+         */
+
+        if (!domain)
+                return -EINVAL;
+
+        if (type) {
+                if (convert_idna) {
+                        r = dns_name_apply_idna(domain, &buf);
+                        if (r < 0)
+                                return r;
+                        if (r > 0)
+                                domain = buf;
+                }
+
+                r = dns_service_join(service, type, domain, &joined);
+                if (r < 0)
+                        return r;
+
+                name = joined;
+        } else {
+                if (service)
+                        return -EINVAL;
+
+                name = domain;
+        }
+
+        q = dns_question_new(1 + with_txt);
+        if (!q)
+                return -ENOMEM;
+
+        key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name);
+        if (!key)
+                return -ENOMEM;
+
+        r = dns_question_add(q, key);
+        if (r < 0)
+                return r;
+
+        if (with_txt) {
+                dns_resource_key_unref(key);
+                key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name);
+                if (!key)
+                        return -ENOMEM;
+
+                r = dns_question_add(q, key);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(q);
+
+        return 0;
+}