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dns-packet: drop unnecessary indentation

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Bail out early if QDCOUNT == 0, similarly to what we already do in
dns_packet_extract_answer() when RRCOUNT == 0.
This commit is contained in:
Frantisek Sumsal
2026-05-20 11:16:29 +02:00
parent b131473ce5
commit 6c119e11b2
1 changed files with 43 additions and 38 deletions
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src/shared/dns-packet.c
+43 -38
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@@ -2452,51 +2452,54 @@ static int dns_packet_extract_question(DnsPacket *p, DnsQuestion **ret_question)
assert(ret_question);
n = DNS_PACKET_QDCOUNT(p);
if (n > 0) {
question = dns_question_new(n);
if (!question)
return -ENOMEM;
if (n == 0) {
*ret_question = NULL;
return 0;
}
_cleanup_set_free_ Set *keys = NULL; /* references to keys are kept by Question */
question = dns_question_new(n);
if (!question)
return -ENOMEM;
keys = set_new(&dns_resource_key_hash_ops);
if (!keys)
return log_oom();
_cleanup_set_free_ Set *keys = NULL; /* references to keys are kept by Question */
/* Pre-allocate the question hashmap, but cap the pre-allocation to a number of questions the
* packet can realistically contain. That is, pick the minimal value from the claimed number
* of questions (n) and a maximum number of potential questions the remaining packet data can
* actually contain: p->size - p->rindex are the remaining unread bytes in the packet, and 5U
* is the minimum size of each question - 1 (QNAME) + 2 (QTYPE) + 2 (QCLASS).
*
* Note for the multiplication: higher multipliers give slightly higher efficiency through
* hash collisions, but the gains quickly drop off after 2. */
r = set_reserve(keys, MIN(n, (p->size - p->rindex) / 5U) * 2);
keys = set_new(&dns_resource_key_hash_ops);
if (!keys)
return log_oom();
/* Pre-allocate the question hashmap, but cap the pre-allocation to a number of questions the
* packet can realistically contain. That is, pick the minimal value from the claimed number
* of questions (n) and a maximum number of potential questions the remaining packet data can
* actually contain: p->size - p->rindex are the remaining unread bytes in the packet, and 5U
* is the minimum size of each question - 1 (QNAME) + 2 (QTYPE) + 2 (QCLASS).
*
* Note for the multiplication: higher multipliers give slightly higher efficiency through
* hash collisions, but the gains quickly drop off after 2. */
r = set_reserve(keys, MIN(n, (p->size - p->rindex) / 5U) * 2);
if (r < 0)
return r;
for (unsigned i = 0; i < n; i++) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
bool qu;
r = dns_packet_read_key(p, &key, &qu, NULL);
if (r < 0)
return r;
for (unsigned i = 0; i < n; i++) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
bool qu;
if (!dns_type_is_valid_query(key->type))
return -EBADMSG;
r = dns_packet_read_key(p, &key, &qu, NULL);
if (r < 0)
return r;
r = set_put(keys, key);
if (r < 0)
return r;
if (r == 0)
/* Already in the Question, let's skip */
continue;
if (!dns_type_is_valid_query(key->type))
return -EBADMSG;
r = set_put(keys, key);
if (r < 0)
return r;
if (r == 0)
/* Already in the Question, let's skip */
continue;
r = dns_question_add_raw(question, key, qu ? DNS_QUESTION_WANTS_UNICAST_REPLY : 0);
if (r < 0)
return r;
}
r = dns_question_add_raw(question, key, qu ? DNS_QUESTION_WANTS_UNICAST_REPLY : 0);
if (r < 0)
return r;
}
*ret_question = TAKE_PTR(question);
@@ -2514,8 +2517,10 @@ static int dns_packet_extract_answer(DnsPacket *p, DnsAnswer **ret_answer) {
assert(ret_answer);
n = DNS_PACKET_RRCOUNT(p);
if (n == 0)
if (n == 0) {
*ret_answer = NULL;
return 0;
}
/* Pre-allocate the answer hashmap, but cap the pre-allocation to a number of RRs the packet can
* realistically contain. That is, pick the minimal value from the claimed number of RRs (n) and a