From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=bn7xwn5r; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTPS id 672C95A0269 for ; Sun, 22 Mar 2026 01:43:53 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774140232; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0Te1ASvsorcDfcJggNJ5ULSGqVFa52yOWbyUrE5UTXg=; b=bn7xwn5rrXDut5pnXl3zgwSeLEntRLmFlAZ1axEdGPCw8Hj98fLtloF5uxVtIcIZF6/eks L2l+BcVcJgV6XWbE86giLf+bdysV2e4wn5fPV7ACWknOF2g3kTmRtYR9DGxdKx/u7M0uJ0 Yzh619V69uZjJ0yM1fqZL373VXXV2ls= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-543-cLYEbY_7OGeHCS1Zn9ZZLw-1; Sat, 21 Mar 2026 20:43:49 -0400 X-MC-Unique: cLYEbY_7OGeHCS1Zn9ZZLw-1 X-Mimecast-MFC-AGG-ID: cLYEbY_7OGeHCS1Zn9ZZLw_1774140228 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 494801800561; Sun, 22 Mar 2026 00:43:48 +0000 (UTC) Received: from jmaloy-thinkpadp16vgen1.rmtcaqc.csb (unknown [10.22.64.183]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 6ACF418001FE; Sun, 22 Mar 2026 00:43:47 +0000 (UTC) From: Jon Maloy To: sbrivio@redhat.com, dgibson@redhat.com, david@gibson.dropbear.id.au, jmaloy@redhat.com, passt-dev@passt.top Subject: [PATCH v6 10/13] migrate: Update protocol to v3 for multi-address support Date: Sat, 21 Mar 2026 20:43:30 -0400 Message-ID: <20260322004333.365713-11-jmaloy@redhat.com> In-Reply-To: <20260322004333.365713-1-jmaloy@redhat.com> References: <20260322004333.365713-1-jmaloy@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: OCmWGorNxyf9lNLelczf1zQiNN95zjdA3DNRN-cjpkw_1774140228 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: FB2NGLLMX5B35XENWIPUAGYK34LFWYDR X-Message-ID-Hash: FB2NGLLMX5B35XENWIPUAGYK34LFWYDR X-MailFrom: jmaloy@redhat.com 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 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: We update the migration protocol to version 3 to support distributing multiple addresses from the unified address array. The new protocol migrates all address entries in the array, along with their prefix lengths and flags, and leaves it to the receiver to filter which ones he wants to apply. Signed-off-by: Jon Maloy --- v4: - Broke out as separate commit - Made number of transferable addresses variable v6: - Separated internal and wire transfer format --- migrate.c | 178 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 178 insertions(+) diff --git a/migrate.c b/migrate.c index a92301b..7b9a2f6 100644 --- a/migrate.c +++ b/migrate.c @@ -44,6 +44,71 @@ struct migrate_seen_addrs_v2 { unsigned char mac[ETH_ALEN]; } __attribute__((packed)); +/** + * Wire format flags for address migration (v3) + * These are stable values - do not change existing assignments + */ +#define MIGRATE_ADDR_USER BIT(0) +#define MIGRATE_ADDR_HOST BIT(1) +#define MIGRATE_ADDR_LINKLOCAL BIT(2) +#define MIGRATE_ADDR_OBSERVED BIT(3) + +/** + * struct migrate_addr_v3 - Wire format for a single address entry + * @addr: IPv6 or IPv4-mapped address (16 bytes) + * @prefix_len: Prefix length + * @flags: MIGRATE_ADDR_* flags (wire format) + */ +struct migrate_addr_v3 { + struct in6_addr addr; + uint8_t prefix_len; + uint8_t flags; +} __attribute__((__packed__)); + +/** + * flags_to_wire() - Convert internal flags to stable wire format + * @flags: Internal CONF_ADDR_* flags + * + * Return: Wire format MIGRATE_ADDR_* flags + */ +static uint8_t flags_to_wire(uint8_t flags) +{ + uint8_t wire = 0; + + if (flags & CONF_ADDR_USER) + wire |= MIGRATE_ADDR_USER; + if (flags & CONF_ADDR_HOST) + wire |= MIGRATE_ADDR_HOST; + if (flags & CONF_ADDR_LINKLOCAL) + wire |= MIGRATE_ADDR_LINKLOCAL; + if (flags & CONF_ADDR_OBSERVED) + wire |= MIGRATE_ADDR_OBSERVED; + + return wire; +} + +/** + * flags_from_wire() - Convert wire format flags to internal format + * @wire: Wire format MIGRATE_ADDR_* flags + * + * Return: Internal CONF_ADDR_* flags + */ +static uint8_t flags_from_wire(uint8_t wire) +{ + uint8_t flags = 0; + + if (wire & MIGRATE_ADDR_USER) + flags |= CONF_ADDR_USER; + if (wire & MIGRATE_ADDR_HOST) + flags |= CONF_ADDR_HOST; + if (wire & MIGRATE_ADDR_LINKLOCAL) + flags |= CONF_ADDR_LINKLOCAL; + if (wire & MIGRATE_ADDR_OBSERVED) + flags |= CONF_ADDR_OBSERVED; + + return flags; +} + /** * seen_addrs_source_v2() - Copy and send guest observed addresses from source * @c: Execution context @@ -126,6 +191,98 @@ static int seen_addrs_target_v2(struct ctx *c, return 0; } +/** + * addrs_source_v3() - Send all addresses with flags from source + * @c: Execution context + * @stage: Migration stage, unused + * @fd: File descriptor for state transfer + * + * Send all address entries using a stable wire format. Each field is + * serialized explicitly to avoid coupling the wire format to internal + * structure layout or flag bit assignments. + * + * Return: 0 on success, positive error code on failure + */ +/* cppcheck-suppress [constParameterCallback, unmatchedSuppression] */ +static int addrs_source_v3(struct ctx *c, + const struct migrate_stage *stage, int fd) +{ + uint8_t addr_count = c->addr_count; + const struct guest_addr *a; + + (void)stage; + + /* Send count first */ + if (write_all_buf(fd, &addr_count, sizeof(addr_count))) + return errno; + + /* Send each address in stable wire format */ + for_each_addr(a, c, 0) { + struct migrate_addr_v3 wire = { + .addr = a->addr.a6, + .prefix_len = a->prefix_len, + .flags = flags_to_wire(a->flags), + }; + + if (write_all_buf(fd, &wire, sizeof(wire))) + return errno; + } + + /* Send MAC */ + if (write_all_buf(fd, c->guest_mac, ETH_ALEN)) + return errno; + + return 0; +} + +/** + * addrs_target_v3() - Receive addresses on target + * @c: Execution context + * @stage: Migration stage, unused + * @fd: File descriptor for state transfer + * + * Receive address entries from the stable wire format and merge only + * observed addresses into local array. Source sends all addresses for + * forward compatibility, but target only applies those marked as observed. + * + * Return: 0 on success, positive error code on failure + */ +static int addrs_target_v3(struct ctx *c, + const struct migrate_stage *stage, int fd) +{ + uint8_t addr_count, i; + + (void)stage; + + if (read_all_buf(fd, &addr_count, sizeof(addr_count))) + return errno; + + if (addr_count > MAX_GUEST_ADDRS) + addr_count = MAX_GUEST_ADDRS; + + /* Read each address from stable wire format */ + for (i = 0; i < addr_count; i++) { + struct migrate_addr_v3 wire; + struct guest_addr addr; + + if (read_all_buf(fd, &wire, sizeof(wire))) + return errno; + + addr.addr.a6 = wire.addr; + addr.prefix_len = wire.prefix_len; + addr.flags = flags_from_wire(wire.flags); + + if (addr.flags & CONF_ADDR_OBSERVED) + fwd_set_addr(c, &addr.addr, addr.flags, + addr.prefix_len); + } + + if (read_all_buf(fd, c->guest_mac, ETH_ALEN)) + return errno; + + return 0; +} + /* Stages for version 2 */ static const struct migrate_stage stages_v2[] = { { @@ -146,8 +303,29 @@ static const struct migrate_stage stages_v2[] = { { 0 }, }; +/* Stages for version 3 (multiple observed IPv4 addresses) */ +static const struct migrate_stage stages_v3[] = { + { + .name = "addresses", + .source = addrs_source_v3, + .target = addrs_target_v3, + }, + { + .name = "prepare flows", + .source = flow_migrate_source_pre, + .target = NULL, + }, + { + .name = "transfer flows", + .source = flow_migrate_source, + .target = flow_migrate_target, + }, + { 0 }, +}; + /* Supported encoding versions, from latest (most preferred) to oldest */ static const struct migrate_version versions[] = { + { 3, stages_v3, }, { 2, stages_v2, }, /* v1 was released, but not widely used. It had bad endianness for the * MSS and omitted timestamps, which meant it usually wouldn't work. -- 2.52.0