From patchwork Sun Sep 26 15:58:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Hunt X-Patchwork-Id: 12518327 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A045C433EF for ; Sun, 26 Sep 2021 15:58:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E6B6560FC1 for ; Sun, 26 Sep 2021 15:58:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231993AbhIZQAP (ORCPT ); Sun, 26 Sep 2021 12:00:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231178AbhIZQAM (ORCPT ); Sun, 26 Sep 2021 12:00:12 -0400 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26C9FC061570 for ; Sun, 26 Sep 2021 08:58:36 -0700 (PDT) Received: by mail-wr1-x42c.google.com with SMTP id t18so44441312wrb.0 for ; Sun, 26 Sep 2021 08:58:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=0kzOMWLLbCho8w/fAADwvgy3ak4MtXKkHs3FDjX/fiQ=; b=YjBBICCR+1JNFZlwfMLvavm0yZWwP8lPWb7mprbLvzSMAorR2N5S47tNuji2QqaySR rRrcn+wklrUEKS8JxF7kTUZLEkh3Cc7wbmI0J34xYXclaJurYSk4HYNx1TjsI3QDVto8 MhGHd9cqtKXUhyZY0oFth8u5I63AAsW82lony/mqHgzUG3vKG5O6v/oR9268tyi4Xwhy Qc6277t27iMU4dRNqet3e2c27eBm6zMuRqnhbO8hPHj7rEhAX/xGVfhQttxQokJjU29I 0OrgL1cED2eQD/ydiWO1NJo4OMntJT4NT1KMssk96qlWBJrgRxHUtTFeVMACMjtntGcY QuFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=0kzOMWLLbCho8w/fAADwvgy3ak4MtXKkHs3FDjX/fiQ=; b=NQUNcFadM6+IsEh3iRuIf6DujtqjIKyg1AHIO/mQ9dd1WVZpPH2adnvCIvSGNCG2Uy dGmTM3eB8cf6+g4OwS55gJ+BTy3Hh8vzn5L3EgaroNOeVmWyVxAJdkY4eud+F6vr/JtW OG8yw73ZU+fZoKCwjG3v3Dmp+HIDcJRFS0QxEfxnZK9ERMb6aE86My9zVs8rrBCPMXZU lIDCmvnNflmtvLkYdBclxgMtW0mK72hqjfhqS3a3LL9/5kLyDF+75LDElM0xLXTrWoK9 WiLBIOAQ9suoJaybJH0Z84veS3mst/WJgyvs37STY+Ap1rg6GPdqXOWhaJ7ZTP+/Ql5P WR1Q== X-Gm-Message-State: AOAM533ADo1mK+bKFmHMO3LAEEwTn5hTcY/Euq4sWwS5q1NfhP3b6QYa hvBfVGuPnXaTW+5jHODNQN1ChlsxAnY= X-Google-Smtp-Source: ABdhPJwOBoycu6TDrDmNdMbYDSX233gPV+rTVE60I5DLaK308R19cvX1IBgYxGZ8wQHjBBrR/Mxxag== X-Received: by 2002:a5d:5241:: with SMTP id k1mr22627162wrc.227.1632671914685; Sun, 26 Sep 2021 08:58:34 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id w23sm2972467wmi.6.2021.09.26.08.58.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Sep 2021 08:58:34 -0700 (PDT) Message-Id: In-Reply-To: References: Date: Sun, 26 Sep 2021 15:58:33 +0000 Subject: [PATCH v2] connect: also update offset for features without values Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Jeff King , Taylor Blau , "brian m . carlson" , Eric Sunshine , Andrzej Hunt , Andrzej Hunt Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Andrzej Hunt From: Andrzej Hunt parse_feature_value() takes an offset, and uses it to seek past the point in features_list that we've already seen. However if the feature being searched for does not specify a value, the offset is not updated. Therefore if we call parse_feature_value() in a loop on a value-less feature, we'll keep on parsing the same feature over and over again. This usually isn't an issue: there's no point in using next_server_feature_value() to search for repeated instances of the same capability unless that capability typically specifies a value - but a broken server could send a response that omits the value for a feature even when we are expecting a value. Therefore we add an offset update calculation for the no-value case, which helps ensure that loops using next_server_feature_value() will always terminate. next_server_feature_value(), and the offset calculation, were first added in 2.28 in 2c6a403d96 (connect: add function to parse multiple v1 capability values, 2020-05-25). Thanks to Peff for authoring the test. Co-authored-by: Jeff King Signed-off-by: Jeff King Signed-off-by: Andrzej Hunt --- connect: also update offset for features without values V2 incorporates Peff's test and test stability improvements, and attempts to improve the commit message. ATB, Andrzej Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1091%2Fahunt%2Fconnectloop-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1091/ahunt/connectloop-v2 Pull-Request: https://github.com/git/git/pull/1091 Range-diff vs v1: 1: dcbb05ddc4b ! 1: 908e4e6c4ed connect: also update offset for features without values @@ Metadata ## Commit message ## connect: also update offset for features without values - parse_feature_value() does not update offset if the feature being - searched for does not specify a value. A loop that uses - parse_feature_value() to find a feature which was specified without a - value therefore might never exit (such loops will typically use - next_server_feature_value() as opposed to parse_feature_value() itself). - This usually isn't an issue: there's no point in using + parse_feature_value() takes an offset, and uses it to seek past the + point in features_list that we've already seen. However if the feature + being searched for does not specify a value, the offset is not + updated. Therefore if we call parse_feature_value() in a loop on a + value-less feature, we'll keep on parsing the same feature over and over + again. This usually isn't an issue: there's no point in using next_server_feature_value() to search for repeated instances of the same capability unless that capability typically specifies a value - but a broken server could send a response that omits the value for a feature @@ Commit message always terminate. next_server_feature_value(), and the offset calculation, were first - added in 2.28 in: - 2c6a403d96 (connect: add function to parse multiple v1 capability values, 2020-05-25) + added in 2.28 in 2c6a403d96 (connect: add function to parse multiple + v1 capability values, 2020-05-25). Thanks to Peff for authoring the test. @@ t/t5704-protocol-violations.sh: test_expect_success 'extra delim packet in v2 fe +test_expect_success 'bogus symref in v0 capabilities' ' + test_commit foo && + oid=$(git rev-parse HEAD) && ++ dst=refs/heads/foo && + { -+ printf "%s HEAD\0symref object-format=%s\n" "$oid" "$GIT_DEFAULT_HASH" | ++ printf "%s HEAD\0symref object-format=%s symref=HEAD:%s\n" \ ++ "$oid" "$GIT_DEFAULT_HASH" "$dst" | + test-tool pkt-line pack-raw-stdin && + printf "0000" + } >input && -+ git ls-remote --upload-pack="cat input ;:" . >actual && -+ printf "%s\tHEAD\n" "$oid" >expect && ++ git ls-remote --symref --upload-pack="cat input; read junk;:" . >actual && ++ printf "ref: %s\tHEAD\n%s\tHEAD\n" "$dst" "$oid" >expect && + test_cmp expect actual +' + connect.c | 2 ++ t/t5704-protocol-violations.sh | 15 +++++++++++++++ 2 files changed, 17 insertions(+) base-commit: 4c38ced6901a8523cea197b31b2616240ec9fb6e diff --git a/connect.c b/connect.c index aff13a270e6..eaf7d6d2618 100644 --- a/connect.c +++ b/connect.c @@ -557,6 +557,8 @@ const char *parse_feature_value(const char *feature_list, const char *feature, i if (!*value || isspace(*value)) { if (lenp) *lenp = 0; + if (offset) + *offset = found + len - feature_list; return value; } /* feature with a value (e.g., "agent=git/1.2.3") */ diff --git a/t/t5704-protocol-violations.sh b/t/t5704-protocol-violations.sh index 5c941949b98..bc393d7c319 100755 --- a/t/t5704-protocol-violations.sh +++ b/t/t5704-protocol-violations.sh @@ -32,4 +32,19 @@ test_expect_success 'extra delim packet in v2 fetch args' ' test_i18ngrep "expected flush after fetch arguments" err ' +test_expect_success 'bogus symref in v0 capabilities' ' + test_commit foo && + oid=$(git rev-parse HEAD) && + dst=refs/heads/foo && + { + printf "%s HEAD\0symref object-format=%s symref=HEAD:%s\n" \ + "$oid" "$GIT_DEFAULT_HASH" "$dst" | + test-tool pkt-line pack-raw-stdin && + printf "0000" + } >input && + git ls-remote --symref --upload-pack="cat input; read junk;:" . >actual && + printf "ref: %s\tHEAD\n%s\tHEAD\n" "$dst" "$oid" >expect && + test_cmp expect actual +' + test_done