From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202502 header.b=EyoEPULI; dkim-atps=neutral Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 863655A0275 for ; Mon, 10 Feb 2025 10:18:15 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202502; t=1739179087; bh=nwiJI8XPkZPG+riNd6pGazIp8mPA6aBfpuQG8sTjiIQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EyoEPULIDxcwBrZm5064IKN21Rh7PBgIBQOe2XWrxZtxh5d2pa0YRsdEnv2vu4+wQ tlAPXLLKm2ceE2fO/Tl3AAcFfyuokiw5u4idqMCbjZuj2ZM7lJfSE6AWAtFIMYK07P pHjYumRvrY4oJ9AqaOZ4ge7CQ/o1RBSOyaWvzLQzanJxbrnJGLs/NCJzfqHKJAGVBb oTUOUG6EAKtQH2oLwNxnYD0URU+72l2pATi5bv+ypbYVkzUs1jUa+O3tHDYelKBAYz 3Hh7mvDSZcQVHx35PDJvuDmGnG6VfRNps+5wVMUA2AvCCi9g9KhCldlpv8tMA1yvP5 eCkJaUNGyQd4Q== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4YrzWg4rKPz4wy1; Mon, 10 Feb 2025 20:18:07 +1100 (AEDT) From: David Gibson To: passt-dev@passt.top, Stefano Brivio Subject: [PATCH v14 03/14] migrate: Migrate guest observed addresses Date: Mon, 10 Feb 2025 20:17:54 +1100 Message-ID: <20250210091805.2261228-4-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250210091805.2261228-1-david@gibson.dropbear.id.au> References: <20250210091805.2261228-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: 6AGDCQ4X6EIEFDQQLYV4TNMFY5OWX2C2 X-Message-ID-Hash: 6AGDCQ4X6EIEFDQQLYV4TNMFY5OWX2C2 X-MailFrom: dgibson@gandalf.ozlabs.org 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: David Gibson 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: Most of the information in struct ctx doesn't need to be migrated. Either it's strictly back end information which is allowed to differ between the two ends, or it must already be configured identically on the two ends. There are a few exceptions though. In particular passt learns several addresses of the guest by observing what it sends out. If we lose this information across migration we might get away with it, but if there are active flows we might misdirect some packets before re-learning the guest address. Avoid this by migrating the guest's observed addresses. Signed-off-by: David Gibson [sbrivio: Coding style stuff, comments, etc.] Signed-off-by: Stefano Brivio Message-ID: <20250209222005.1640077-3-sbrivio@redhat.com> Signed-off-by: David Gibson --- migrate.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/migrate.c b/migrate.c index aeac8722..72a6d40a 100644 --- a/migrate.c +++ b/migrate.c @@ -27,8 +27,81 @@ /* Magic identifier for migration data */ #define MIGRATE_MAGIC 0xB1BB1D1B0BB1D1B0 +/** + * struct migrate_seen_addrs_v1 - Migratable guest addresses for v1 state stream + * @addr6: Observed guest IPv6 address + * @addr6_ll: Observed guest IPv6 link-local address + * @addr4: Observed guest IPv4 address + * @mac: Observed guest MAC address + */ +struct migrate_seen_addrs_v1 { + struct in6_addr addr6; + struct in6_addr addr6_ll; + struct in_addr addr4; + unsigned char mac[ETH_ALEN]; +} __attribute__((packed)); + +/** + * seen_addrs_source_v1() - Copy and send guest observed addresses from source + * @c: Execution context + * @stage: Migration stage, unused + * @fd: File descriptor for state transfer + * + * Return: 0 on success, positive error code on failure + */ +/* cppcheck-suppress [constParameterCallback, unmatchedSuppression] */ +static int seen_addrs_source_v1(struct ctx *c, + const struct migrate_stage *stage, int fd) +{ + struct migrate_seen_addrs_v1 addrs = { + .addr6 = c->ip6.addr_seen, + .addr6_ll = c->ip6.addr_ll_seen, + .addr4 = c->ip4.addr_seen, + }; + + (void)stage; + + memcpy(addrs.mac, c->guest_mac, sizeof(addrs.mac)); + + if (write_all_buf(fd, &addrs, sizeof(addrs))) + return errno; + + return 0; +} + +/** + * seen_addrs_target_v1() - Receive and use guest observed addresses on target + * @c: Execution context + * @stage: Migration stage, unused + * @fd: File descriptor for state transfer + * + * Return: 0 on success, positive error code on failure + */ +static int seen_addrs_target_v1(struct ctx *c, + const struct migrate_stage *stage, int fd) +{ + struct migrate_seen_addrs_v1 addrs; + + (void)stage; + + if (read_all_buf(fd, &addrs, sizeof(addrs))) + return errno; + + c->ip6.addr_seen = addrs.addr6; + c->ip6.addr_ll_seen = addrs.addr6_ll; + c->ip4.addr_seen = addrs.addr4; + memcpy(c->guest_mac, addrs.mac, sizeof(c->guest_mac)); + + return 0; +} + /* Stages for version 1 */ static const struct migrate_stage stages_v1[] = { + { + .name = "observed addresses", + .source = seen_addrs_source_v1, + .target = seen_addrs_target_v1, + }, { 0 }, }; -- 2.48.1