net: dns: remove redundant check in mdns_unpack_query_header

kartben · danieldegrasse · commit 1387657107ec · 2025-06-16T14:04:59.000-04:00
Drop this redundant check that was likely meant to be checking that Z
field is zero but in the case of reception the RFC says it MUST be
ignored anyway.

Signed-off-by: Benjamin Cabé &lt;benjamin@zephyrproject.org&gt;
diff --git a/subsys/net/lib/dns/dns_pack.c b/subsys/net/lib/dns/dns_pack.c
@@ -462,10 +462,6 @@ int mdns_unpack_query_header(struct dns_msg_t *msg, uint16_t *src_id)
 		return -EINVAL;
 	}
 
-	if (dns_header_opcode(dns_header) != 0) {
-		return -EINVAL;
-	}
-
 	if (dns_header_rcode(dns_header) != 0) {
 		return -EINVAL;
 	}

Original file line number	Diff line number	Diff line change
`@@ -462,10 +462,6 @@ int mdns_unpack_query_header(struct dns_msg_t msg, uint16_t src_id)`
`462`	`462`	`return -EINVAL;`
`463`	`463`	`}`
`464`	`464`
`465`		`- if (dns_header_opcode(dns_header) != 0) {`
`466`		`- return -EINVAL;`
`467`		`- }`
`468`		`-`
`469`	`465`	`if (dns_header_rcode(dns_header) != 0) {`
`470`	`466`	`return -EINVAL;`
`471`	`467`	`}`