From owner-freebsd-pf@freebsd.org Tue Aug 1 09:31:06 2017 Return-Path: Delivered-To: freebsd-pf@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id BD85ADC9720 for ; Tue, 1 Aug 2017 09:31:06 +0000 (UTC) (envelope-from vegeta@tuxpowered.net) Received: from mail-wm0-x235.google.com (mail-wm0-x235.google.com [IPv6:2a00:1450:400c:c09::235]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 67EDD6CEC9 for ; Tue, 1 Aug 2017 09:31:06 +0000 (UTC) (envelope-from vegeta@tuxpowered.net) Received: by mail-wm0-x235.google.com with SMTP id m85so9170260wma.1 for ; Tue, 01 Aug 2017 02:31:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuxpowered-net.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:organization:user-agent :mime-version; bh=piD4lHrJEWkc1N5LVS54QOq8Lpx8kNM41U4i/r/Dr4Y=; b=g/jLwrUuE9tRP8De26JF4qGPdKwWErARUPprLk5WVnrMzATz4TXKtNT0Jj/VJmspUe glNUjLSFcrlWh7h4m0sc4TxTuUZgr5RGo2s03xDNK4+dA3uX/hkO10FcxRwFRVrJRyTm sry89ad5CLz1GE3s+p6rBIfBJbJNFxz4YvUZbIXWdn2bE0xnY+OHmQpeupCJsGAYpu7K e9XX8bzqXqiuVQaNY/PvF+xOC6Ofv4sCe0lTqGNgJIrKLLYXqTIdawbobc1cxomInVLf fcA1noBwEzp50AFWWJ4qZPjShTyaUTVPIL8xYJ6FowmBg61Og273R0VjUPuIXPRvRNbF B99Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:organization :user-agent:mime-version; bh=piD4lHrJEWkc1N5LVS54QOq8Lpx8kNM41U4i/r/Dr4Y=; b=HygLV3mm9mlPsn+gNsAoaT2cd0JerJfgO1asDeIPaUYrsvmrXQqt6gJobAvYXpYTpR 70yjvIr751Op1ZvuqJTFg91coLDGPoRpuhYF/OnTeUOKyHds1AfiDSBkIuF0mc3q/bOL kISkJMsnCyFPf4lHDLXoaMRiHMsSVuua4R4rtYkZrobReltnwAt2Q4ey70ZbhUTvAQEb x//EECRg5NmaZI4WI2hRpeonek0Fn68pgzunRPfa++6E53V40k9MiqKap23zDdcxaVae xAqBHT8FRsYDkpbYcx5XSVHCZIjriLeBKzlrQLwsaJrsofDfCUZmrNUxYjnzoOoZO8My IMHA== X-Gm-Message-State: AIVw1134e9oPSFhjYrJKSz7Gpf+d/WurLk9ncQfSelRHZilcVfK8KIPX B8qVzaPqutDRhh3owMgw3Q== X-Received: by 10.80.224.200 with SMTP id j8mr16917135edl.230.1501579864113; Tue, 01 Aug 2017 02:31:04 -0700 (PDT) Received: from energia.localnet ([2a00:1f78:fffb:220:c7f7:2dda:4b51:2d6b]) by smtp.gmail.com with ESMTPSA id c57sm8288014eda.46.2017.08.01.02.31.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Aug 2017 02:31:02 -0700 (PDT) From: Kajetan Staszkiewicz To: freebsd-pf@freebsd.org Subject: Is panic() the way to handle errors in pf? Date: Tue, 01 Aug 2017 11:30:58 +0200 Message-ID: <3546113.bA8rVlP40E@energia> Organization: tuxpowered.net User-Agent: KMail/5.2.3 (Linux/4.11.0-3.3-liquorix-amd64; KDE/5.28.0; x86_64; ; ) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4711798.ytLVbzxzOZ"; micalg="pgp-sha1"; protocol="application/pgp-signature" X-BeenThere: freebsd-pf@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Technical discussion and general questions about packet filter \(pf\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Aug 2017 09:31:06 -0000 --nextPart4711798.ytLVbzxzOZ Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Hey, group. A thought came to me: is it really the best thing to panic when errors are encountered within pf? I understand there are situations where it is safer for the kernel to not continue running like some low-level operations in memory allocator or filesystems. But a firewall? Especially that a firewall handles packets coming from the Interent which can be arbitrarily crafted. root:freebsd.git/ (releng/11.1) # git grep panic sys/netpfil/pf/ [11:25:04] sys/netpfil/pf/if_pfsync.c: panic("%s: unable to find deferred state", __func__); sys/netpfil/pf/if_pfsync.c: panic("%s: unexpected sync state %d", __func__, st->sync_state); sys/netpfil/pf/if_pfsync.c: panic("%s: unexpected sync state %d", __func__, st->sync_state); sys/netpfil/pf/if_pfsync.c: panic("%s: unexpected sync state %d", __func__, st->sync_state); sys/netpfil/pf/in4_cksum.c: panic("in4_cksum: offset too short"); sys/netpfil/pf/in4_cksum.c: panic("in4_cksum: bad mbuf chain"); sys/netpfil/pf/pf.c: panic("%s: unknown address family %u", __func__, af); sys/netpfil/pf/pf.c: panic("%s: unknown address family %u", __func__, af); sys/netpfil/pf/pf.c: panic("%s: dir %u", __func__, dir); sys/netpfil/pf/pf.c: panic("%s: unknown type", __func__); sys/netpfil/pf/pf.c: panic("%s: unsupported af %d", __func__, af); sys/netpfil/pf/pf_lb.c: * prefixes (or even IPv4) would cause a panic. sys/netpfil/pf/pf_lb.c: panic("%s: unknown action %u", __func__, r- >action); sys/netpfil/pf/pf_table.c: panic("%s: unknown address family %u", __func__, af); That is 14 places in pf code. Wouldn't it be safer to just drop the packet if it can not be processed? -- | pozdrawiam / greetings | powered by Debian, FreeBSD and CentOS | | Kajetan Staszkiewicz | jabber,email: vegeta()tuxpowered net | | Vegeta | www: http://vegeta.tuxpowered.net | `------------------------^---------------------------------------' --nextPart4711798.ytLVbzxzOZ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQSOEQZObv2B8mf0JbnjtFCvbXs6FAUCWYBKUgAKCRDjtFCvbXs6 FNNJAKDjamCIfdaodewG+RI2va8aidHJuACgzGDuWhOJBeOIJhW0YT93HV7tsRk= =vo2V -----END PGP SIGNATURE----- --nextPart4711798.ytLVbzxzOZ--