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=VIRqIZU2; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id 467CE5A026E for ; Mon, 18 May 2026 15:20:16 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1779110415; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sa9WHFxWnYhljVvspEp6jb5I7yt/Qc73ahOBp1bhwXM=; b=VIRqIZU23VF82zRF7p2Kigwdo2B9aBKBfXu1fA8yVtQ8mu8ab4XgKWUoCIwjV9SIEhnSQe Y27gkIiFs+aKzadnP223/AyjpSbDe7X+YrbJKiSD/NAvB4wteC5I90ij7p1f+5T2jzPB93 TXm8uMOQlgh3p81NMkMoPpzYJiGRD28= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-136-xTxI_YhWM_u1Asisrew4YQ-1; Mon, 18 May 2026 09:20:13 -0400 X-MC-Unique: xTxI_YhWM_u1Asisrew4YQ-1 X-Mimecast-MFC-AGG-ID: xTxI_YhWM_u1Asisrew4YQ_1779110412 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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4E2B3195608B; Mon, 18 May 2026 13:20:12 +0000 (UTC) Received: from anskuma-thinkpadp1gen7.bengluru.csb (unknown [10.74.80.120]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 02E9B18004A3; Mon, 18 May 2026 13:20:08 +0000 (UTC) From: Anshu Kumari To: anskuma@redhat.com, sbrivio@redhat.com, passt-dev@passt.top Subject: [PATCH 1/6] conf: Add --dhcp-opt command-line option Date: Mon, 18 May 2026 18:49:57 +0530 Message-ID: <20260518132002.418296-2-anskuma@redhat.com> In-Reply-To: <20260518132002.418296-1-anskuma@redhat.com> References: <20260518132002.418296-1-anskuma@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: X_OtdmqfALsRSWnap_3aboPIkGhNc-9JkffJ1oPOs_g_1779110412 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: DW7UT6MFP3RKRAIVC5SCCJLKY7NTD2D2 X-Message-ID-Hash: DW7UT6MFP3RKRAIVC5SCCJLKY7NTD2D2 X-MailFrom: anskuma@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 CC: lvivier@redhat.com, jmaloy@redhat.com, david@gibson.dropbear.id.au 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: Introduce the --dhcp-opt flag that allows setting arbitrary DHCP options from command-line in the form of [Option CODE,VALUE]. This patch adds the option storage in struct ctx and CLI parsing; the type-aware value parser and DHCP reply injection follow in subsequent patches. Link: https://bugs.passt.top/show_bug.cgi?id=192 Signed-off-by: Anshu Kumari --- conf.c | 36 +++++++++++++++++++++++++++++++++++- passt.h | 10 ++++++++++ 2 files changed, 45 insertions(+), 1 deletion(-) diff --git a/conf.c b/conf.c index 029b9c7..2624e58 100644 --- a/conf.c +++ b/conf.c @@ -47,6 +47,7 @@ #include "lineread.h" #include "isolation.h" #include "log.h" +#include "dhcp.h" #include "vhost_user.h" #include "epoll_ctl.h" #include "conf.h" @@ -616,7 +617,8 @@ static void usage(const char *name, FILE *f, int status) " -S, --search LIST Space-separated list, search domains\n" " a single, empty option disables the DNS search list\n" " -H, --hostname NAME Hostname to configure client with\n" - " --fqdn NAME FQDN to configure client with\n"); + " --fqdn NAME FQDN to configure client with\n" + " --dhcp-opt CODE,VAL Set DHCP option by code\n"); if (strstr(name, "pasta")) FPRINTF(f, " default: don't use any search list\n"); else @@ -844,6 +846,10 @@ static void conf_print(const struct ctx *c) info(" router: %s", inet_ntop(AF_INET, &c->ip4.guest_gw, buf, sizeof(buf))); + for (i = 0; i < c->custom_opts_count; i++) + info(" option %u: %s", + c->custom_opts[i].code, + c->custom_opts[i].str); } for (i = 0; i < ARRAY_SIZE(c->ip4.dns); i++) { @@ -1233,6 +1239,7 @@ void conf(struct ctx *c, int argc, char **argv) {"migrate-no-linger", no_argument, NULL, 30 }, {"stats", required_argument, NULL, 31 }, {"conf-path", required_argument, NULL, 'c' }, + {"dhcp-opt", required_argument, NULL, 33 }, { 0 }, }; const char *optstring = "+dqfel:hs:c:F:I:p:P:m:a:n:M:g:i:o:D:S:H:461t:u:T:U:"; @@ -1465,6 +1472,33 @@ void conf(struct ctx *c, int argc, char **argv) die("Can't display statistics if not running in foreground"); c->stats = strtol(optarg, NULL, 0); break; + case 33: { + unsigned long code; + const char *comma; + char *end; + + comma = strchr(optarg, ','); + if (!comma) + die("--dhcp-opt requires Option CODE,VALUE format"); + + code = strtoul(optarg, &end, 0); + if (end != comma || code < 1 || code > 254) + die("DHCP option code must be 1-254: %s", + optarg); + + if (c->custom_opts_count >= MAX_CUSTOM_DHCP_OPTS) + die("Too many --dhcp-opt entries (max %d)", + MAX_CUSTOM_DHCP_OPTS); + + c->custom_opts[c->custom_opts_count].code = code; + if (snprintf_check(c->custom_opts[c->custom_opts_count].str, + sizeof(c->custom_opts[0].str), + "%s", comma + 1)) + die("DHCP option value too long: %s", + comma + 1); + c->custom_opts_count++; + break; + } case 'd': c->debug = 1; c->quiet = 0; diff --git a/passt.h b/passt.h index 1726965..acb57dd 100644 --- a/passt.h +++ b/passt.h @@ -263,6 +263,16 @@ struct ctx { char hostname[PASST_MAXDNAME]; char fqdn[PASST_MAXDNAME]; +#define MAX_CUSTOM_DHCP_OPTS 32 + + struct { + uint8_t code; + uint8_t len; + uint8_t val[255]; + char str[256]; + } custom_opts[MAX_CUSTOM_DHCP_OPTS]; + int custom_opts_count; + int ifi6; struct ip6_ctx ip6; -- 2.54.0