[nrf fromtree] net: lib: coap_client: Return -errno from send_request()

Return the -errno when zsock_sendto() or zsock_recvfrom() fails, so
rest of the code can deal with return values, instead of separately
comparing errno and return value.

Signed-off-by: Seppo Takalo <[email protected]>
(cherry picked from commit 48434a3)

Author: SeppoTakalo

subsys/net/lib/coap/coap_client.c

@@ -36,12 +36,16 @@ static struct coap_client_internal_request *get_request_with_mid(struct coap_cli
 static int send_request(int sock, const void *buf, size_t len, int flags,
 			const struct sockaddr *dest_addr, socklen_t addrlen)
 {
+	int ret;
+
 	LOG_HEXDUMP_DBG(buf, len, "Send CoAP Request:");
 	if (addrlen == 0) {
-		return zsock_sendto(sock, buf, len, flags, NULL, 0);
+		ret = zsock_sendto(sock, buf, len, flags, NULL, 0);
 	} else {
-		return zsock_sendto(sock, buf, len, flags, dest_addr, addrlen);
+		ret = zsock_sendto(sock, buf, len, flags, dest_addr, addrlen);
 	}
+
+	return ret >= 0 ? ret : -errno;
 }
 
 static int receive(int sock, void *buf, size_t max_len, int flags,
@@ -57,7 +61,7 @@ static int receive(int sock, void *buf, size_t max_len, int flags,
 	if (err > 0) {
 		LOG_HEXDUMP_DBG(buf, err, "Receive CoAP Response:");
 	}
-	return err;
+	return err >= 0 ? err : -errno;
 }
 
 /** Reset all fields to zero.
@@ -493,13 +497,12 @@ static int resend_request(struct coap_client *client,
 					client->socklen);
 		if (ret > 0) {
 			ret = 0;
-		} else if (ret == -1 && errno == EAGAIN) {
+		} else if (ret == -EAGAIN) {
 			/* Restore the pending structure, retry later */
 			internal_req->pending = tmp;
 			/* Not a fatal socket error, will trigger a retry */
 			ret = 0;
 		} else {
-			ret = -errno;
 			LOG_ERR("Failed to resend request, %d", ret);
 		}
 	} else {