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=lEf+Ke6C; dkim-atps=neutral Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by passt.top (Postfix) with ESMTPS id 596855A0275 for ; Thu, 03 Apr 2025 07:38:21 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202502; t=1743658684; bh=dhh/KhoWehyKCiyPDnfrh31aK2PcW5w5Y87JQIuQ0Zg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lEf+Ke6CIkJEmCTZOs+XrSPnOc3TgOXeD5sgS3Me7IOwU/P6u7tm9p0dbX12djiYi U2HQiEX4hFV1JuDQTtKJ5wRAMe+VM/YtkL3pQqpXIwyCCWlWUoDqPqNyIesrAihufo tkE8GzxzkuZle+3aQ2sn1G3WCqzpuEdv4hTCHdc7nWuzMnax35txkaZQwLTFcRlHda twRDXKGJcYBmITnG7mH+d5+pfq8icGsPSmUJsNtaWgbbRXEPAUrT9ZEXaEFVAQba4B qTOyLcoGlKyeuJlGJ6m9zeqF3WN8SA5O++sV3IF93k3cwizyFHmAjzJNG/vtMrdta5 wb1KYX42i0/tQ== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4ZSr9m5b43z4xN2; Thu, 3 Apr 2025 16:38:04 +1100 (AEDT) Date: Thu, 3 Apr 2025 16:14:37 +1100 From: David Gibson To: Laurent Vivier Subject: Re: [PATCH 10/18] tcp: Convert tcp_tap_handler() to use iov_tail Message-ID: References: <20250402172343.858187-1-lvivier@redhat.com> <20250402172343.858187-11-lvivier@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ZmKltY8UCCYk8vc6" Content-Disposition: inline In-Reply-To: <20250402172343.858187-11-lvivier@redhat.com> Message-ID-Hash: DCGB6TOGS7TKTQZMSGIHIK4E7B6C2ZCG X-Message-ID-Hash: DCGB6TOGS7TKTQZMSGIHIK4E7B6C2ZCG 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: passt-dev@passt.top 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: --ZmKltY8UCCYk8vc6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Apr 02, 2025 at 07:23:35PM +0200, Laurent Vivier wrote: > Use packet_base() and extract headers using IOV_REMOVE_HEADER() > and iov_peek_header_() rather than packet_get(). >=20 > Signed-off-by: Laurent Vivier > --- > tcp.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) >=20 > diff --git a/tcp.c b/tcp.c > index a4c840e6721c..790714a08793 100644 > --- a/tcp.c > +++ b/tcp.c > @@ -310,6 +310,8 @@ > #include "tcp_buf.h" > #include "tcp_vu.h" > =20 Some explanation of the derivation would be good here. > +#define OPTLEN_MAX (((1UL << 4) - 6) * 4UL) > + > #ifndef __USE_MISC > /* From Linux UAPI, missing in netinet/tcp.h provided by musl */ > struct tcp_repair_opt { > @@ -1957,7 +1959,10 @@ int tcp_tap_handler(const struct ctx *c, uint8_t p= if, sa_family_t af, > { > struct tcp_tap_conn *conn; > const struct tcphdr *th; > + char optsc[OPTLEN_MAX]; > + struct iov_tail data; > size_t optlen, len; > + struct tcphdr thc; > const char *opts; > union flow *flow; > flow_sidx_t sidx; > @@ -1966,15 +1971,19 @@ int tcp_tap_handler(const struct ctx *c, uint8_t = pif, sa_family_t af, > =20 > (void)pif; > =20 > - th =3D packet_get(p, idx, 0, sizeof(*th), &len); > + if (!packet_base(p, idx, &data)) > + return 1; > + > + len =3D iov_tail_size(&data); 'l4len', please. > + > + th =3D IOV_REMOVE_HEADER(&data, thc); > if (!th) > return 1; > - len +=3D sizeof(*th); > =20 > optlen =3D th->doff * 4UL - sizeof(*th); > /* Static checkers might fail to see this: */ > - optlen =3D MIN(optlen, ((1UL << 4) /* from doff width */ - 6) * 4UL); > - opts =3D packet_get(p, idx, sizeof(*th), optlen, NULL); > + optlen =3D MIN(optlen, OPTLEN_MAX); > + opts =3D (char *)iov_peek_header_(&data, &optsc[0], optlen, 1); > =20 > sidx =3D flow_lookup_af(c, IPPROTO_TCP, PIF_TAP, af, saddr, daddr, > ntohs(th->source), ntohs(th->dest)); --=20 David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson --ZmKltY8UCCYk8vc6 Content-Type: application/pgp-signature; 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