From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 4C7B65A031B for ; Fri, 05 Jul 2024 04:07:42 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202312; t=1720145251; bh=20o46Lj+S+QF3LzhPmcUeUjBHb5tAKCK+PRPTJ9/9ds=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I5NreeGFUIPG7YpA3igKWEwu4CANWfEw83XLh2L2+Fy1dtyUcHqZQbTsEyMTvB1OW +SO2DvF3X9ppDrCt1d65gtVsvPNbcNyftWRF2BGz3+v7fZlJYLv6bdgt9S/5ZY/G4l uR2o5P8IX9rKBuHbnFqyrRVMNBGpDwVECROBguaSmO7MQqpitmu249GtUOk6FHI4bo X3AW0FQFzaF7HVbvt4e/bNGjvuYVw9Oq0g+LvR+1unXMc0YGAERLsUt4csV0ClA+D+ CHWqQJaKg27RzsVHOTvMEnU4Vcak8BDV9XplE0Eis1ptDwcvzj4ofiEVGhZhDX+X/f SBoTU4vuAFuqQ== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4WFcNM1fwDz4xPh; Fri, 5 Jul 2024 12:07:31 +1000 (AEST) From: David Gibson To: Stefano Brivio , passt-dev@passt.top Subject: [PATCH v7 19/27] fwd: Update flow forwarding logic for UDP Date: Fri, 5 Jul 2024 12:07:16 +1000 Message-ID: <20240705020724.3447719-20-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240705020724.3447719-1-david@gibson.dropbear.id.au> References: <20240705020724.3447719-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: CJLTKLOPQXCCMOY5BBMJIPJYICVITZD6 X-Message-ID-Hash: CJLTKLOPQXCCMOY5BBMJIPJYICVITZD6 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: jmaloy@redhat.com, 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: Add logic to the fwd_nat_from_*() functions to forwarding UDP packets. The logic here doesn't exactly match our current forwarding, since our current forwarding has some very strange and buggy edge cases. Instead it's attempting to replicate what appears to be the intended logic behind the current forwarding. Signed-off-by: David Gibson --- fwd.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/fwd.c b/fwd.c index 5731a536..4377de44 100644 --- a/fwd.c +++ b/fwd.c @@ -169,12 +169,15 @@ void fwd_scan_ports_init(struct ctx *c) uint8_t fwd_nat_from_tap(const struct ctx *c, uint8_t proto, const struct flowside *ini, struct flowside *tgt) { - (void)proto; - tgt->eaddr = ini->faddr; tgt->eport = ini->fport; - if (!c->no_map_gw) { + if (proto == IPPROTO_UDP && tgt->eport == 53) { + if (inany_equals4(&tgt->eaddr, &c->ip4.dns_match)) + tgt->eaddr = inany_from_v4(c->ip4.dns_host); + else if (inany_equals6(&tgt->eaddr, &c->ip6.dns_match)) + tgt->eaddr.a6 = c->ip6.dns_host; + } else if (!c->no_map_gw) { if (inany_equals4(&tgt->eaddr, &c->ip4.gw)) tgt->eaddr = inany_loopback4; else if (inany_equals6(&tgt->eaddr, &c->ip6.gw)) @@ -191,6 +194,10 @@ uint8_t fwd_nat_from_tap(const struct ctx *c, uint8_t proto, /* Let the kernel pick a host side source port */ tgt->fport = 0; + if (proto == IPPROTO_UDP) { + /* But for UDP we preserve the source port */ + tgt->fport = ini->eport; + } return PIF_HOST; } @@ -232,9 +239,14 @@ uint8_t fwd_nat_from_splice(const struct ctx *c, uint8_t proto, tgt->eport = ini->fport; if (proto == IPPROTO_TCP) tgt->eport += c->tcp.fwd_out.delta[tgt->eport]; + else if (proto == IPPROTO_UDP) + tgt->eport += c->udp.fwd_out.f.delta[tgt->eport]; /* Let the kernel pick a host side source port */ tgt->fport = 0; + if (proto == IPPROTO_UDP) + /* But for UDP preserve the source port */ + tgt->fport = ini->eport; return PIF_HOST; } @@ -256,20 +268,26 @@ uint8_t fwd_nat_from_host(const struct ctx *c, uint8_t proto, tgt->eport = ini->fport; if (proto == IPPROTO_TCP) tgt->eport += c->tcp.fwd_in.delta[tgt->eport]; + else if (proto == IPPROTO_UDP) + tgt->eport += c->udp.fwd_in.f.delta[tgt->eport]; if (c->mode == MODE_PASTA && inany_is_loopback(&ini->eaddr) && - proto == IPPROTO_TCP) { + (proto == IPPROTO_TCP || proto == IPPROTO_UDP)) { /* spliceable */ /* Preserve the specific loopback adddress used, but let the * kernel pick a source port on the target side */ tgt->faddr = ini->eaddr; tgt->fport = 0; + if (proto == IPPROTO_UDP) + /* But for UDP preserve the source port */ + tgt->fport = ini->eport; if (inany_v4(&ini->eaddr)) tgt->eaddr = inany_loopback4; else tgt->eaddr = inany_loopback6; + return PIF_SPLICE; } -- 2.45.2