From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=njh.eu Received: from mail.notjusthosting.com (mail.notjusthosting.com [IPv6:2a01:4f8:a0:516f:1::1]) by passt.top (Postfix) with ESMTPS id 10A1A5A095E for ; Tue, 16 Sep 2025 21:23:21 +0200 (CEST) Received: from [2a01:599:10d:cf12:83c1:fa7e:d576:60f] (helo=vlap) by mail.notjusthosting.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1uybGq-0001lF-Ji; Tue, 16 Sep 2025 21:23:20 +0200 From: Volker Diels-Grabsch To: passt-dev@passt.top Subject: [PATCH 5/5] Improve clarity of comment Date: Tue, 16 Sep 2025 21:21:16 +0200 Message-ID: <20250916192209.3986375-6-v@njh.eu> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20250916192209.3986375-1-v@njh.eu> References: <20250916192209.3986375-1-v@njh.eu> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: 4P2K6LGEEFX36MRJMVZBPDVGFQSUA3CL X-Message-ID-Hash: 4P2K6LGEEFX36MRJMVZBPDVGFQSUA3CL X-MailFrom: v@njh.eu X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Volker Diels-Grabsch X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: The new wording clarifies that we (1) use the broadcast MAC address only until we know the actual MAC address of the guest, and (2) our first packets will not necessarily "reach" the guest, in the sense of being processed rather than dropped. (Which is why we actively send an initial ARP and/or NDP message, to get the guest MAC address as soon as possible.) Signed-off-by: Volker Diels-Grabsch --- tap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tap.c b/tap.c index 0f8ee25..399eeaa 100644 --- a/tap.c +++ b/tap.c @@ -1512,9 +1512,9 @@ void tap_backend_init(struct ctx *c) case MODE_PASST: tap_sock_unix_init(c); - /* In passt mode, we don't know the guest's MAC address until it - * sends us packets. Use the broadcast address so that our - * first packets will reach it. + /* In passt mode, we don't know the guest's MAC address until + * it sends us packets. Until then, use the broadcast address + * so that our first packets will have a chance to reach it. */ memcpy(&c->guest_mac, MAC_BROADCAST, sizeof(c->guest_mac)); break; -- 2.47.3