From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.5 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id DDBBB1F406 for ; Thu, 4 Jan 2018 00:17:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751625AbeADARO (ORCPT ); Wed, 3 Jan 2018 19:17:14 -0500 Received: from mail-qt0-f179.google.com ([209.85.216.179]:43723 "EHLO mail-qt0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751313AbeADARN (ORCPT ); Wed, 3 Jan 2018 19:17:13 -0500 Received: by mail-qt0-f179.google.com with SMTP id w10so85169qtb.10 for ; Wed, 03 Jan 2018 16:17:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=N7qkU1E3F3QNGTd+pblHcVW2Rhz0ib3L4oZZmd2euKM=; b=jGFPcNseQq3JpsCRyOMzIQWhrRZnFHbPNSpmratQR6wsQzbrsW4ZoIMIUXKgWNgLvI k+tfX7Mbc82mEes5ZcG/1RC0Pn3WMAHut8IiNEFf1Y4R7thqFXPc1Bawm6KFPbISkIF4 yRNOQ3+LB0eYPOVNFBOeFFAvL4tYrv14JQJxsNl8XaQqtZ82Tefoq20HWTagndJyBHQ7 RljUFH/Xdq6XdjbL+RZd1rFvxM/15xN/Q1FSMUgx7IK81P7NHmdtBkjEQZU+1HU5HDYl LI7UZtEb8qYDSaTbnX6oTxqdfmOkrzUmcHkJTMRS6EZbAwf935ID9iqHsJr0i/VODyp+ T/sQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=N7qkU1E3F3QNGTd+pblHcVW2Rhz0ib3L4oZZmd2euKM=; b=ivtYsOgIcsbNzTl+zjySgOxwUHY6KUMVIPJg6VABbOGkFMAxfBcBhtxJapTeeYVqEi 3vZ2ObYpx49dT9KnDOVRrrpNDKHwgRFVIFFbHhzmFE7xrFEhOko79OV3yrLlN978E4ZL GTyJorflftQuxgzFHgVqjU051xluTkjV9O0q/nIjvWuLJXWd5xUlhca7b2OauNAScTpi ONzN/ZIIjJl52uWj0dRLEjMRrpRgi6LisdwAgRIN2r879AAgDzRNE2+h0Flg/DcXj68B FB4tiTX+vII5oM+ktzvKb4UGdo+ewRBVBc2HS7d0dNkwCddoxa+P/QVFklox5NJTNdRb ckUg== X-Gm-Message-State: AKGB3mJ8BXYwiI1SMcFwCIH6rl14tsriqvktqHAhlCp6h+nkyO2qScOA sbaept2B82DVdc4NyvoyDFqjSW/kWQO5eCZ9ynmRyqk8208= X-Google-Smtp-Source: ACJfBotdt/a7MhM6QlR4pPydyQ9UXjjy9X1zGXgKUzJBU0d1iFyMm57/BZuXwN7MRg6eqaZ/o9ASXIAgGCHuHuuy1OM= X-Received: by 10.237.61.181 with SMTP id i50mr4388373qtf.29.1515025032469; Wed, 03 Jan 2018 16:17:12 -0800 (PST) MIME-Version: 1.0 Received: by 10.140.85.179 with HTTP; Wed, 3 Jan 2018 16:17:11 -0800 (PST) In-Reply-To: <20180103001828.205012-13-bmwill@google.com> References: <20180103001828.205012-1-bmwill@google.com> <20180103001828.205012-13-bmwill@google.com> From: Stefan Beller Date: Wed, 3 Jan 2018 16:17:11 -0800 Message-ID: Subject: Re: [PATCH 12/26] ls-refs: introduce ls-refs server command To: Brandon Williams Cc: git , Junio C Hamano , Jeff King , Philip Oakley , Derrick Stolee , Jonathan Nieder Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Tue, Jan 2, 2018 at 4:18 PM, Brandon Williams wrote: > Introduce the ls-refs server command. In protocol v2, the ls-refs > command is used to request the ref advertisement from the server. Since > it is a command which can be requested (as opposed to mandatory in v1), > a client can sent a number of parameters in its request to limit the ref > advertisement based on provided ref-patterns. > > Signed-off-by: Brandon Williams > --- > Documentation/technical/protocol-v2.txt | 26 +++++++++ > Makefile | 1 + > ls-refs.c | 97 +++++++++++++++++++++++++++++++++ > ls-refs.h | 9 +++ Maybe consider putting any served command into a sub directory? For example the code in builtin/ has laxer rules w.r.t. die()ing as it is a user facing command, whereas some devs want to see code at the root of the repo to not die() at all as the eventual goal is to have a library there. All this code is on the remote side, which also has different traits than the code at the root of the git.git repo; non-localisation comes to mind, but there might be other aspects as well (security?). > serve.c | 2 + > 5 files changed, 135 insertions(+) > create mode 100644 ls-refs.c > create mode 100644 ls-refs.h > > diff --git a/Documentation/technical/protocol-v2.txt b/Documentation/technical/protocol-v2.txt > index b87ba3816..5f4d0e719 100644 > --- a/Documentation/technical/protocol-v2.txt > +++ b/Documentation/technical/protocol-v2.txt > @@ -89,3 +89,29 @@ terminate the connection. > Commands are the core actions that a client wants to perform (fetch, push, > etc). Each command will be provided with a list capabilities and > arguments as requested by a client. > + > + Ls-refs So is it ls-refs or Ls-refs or is any capitalization valid? > +--------- > + > +Ls-refs is the command used to request a reference advertisement in v2. > +Unlike the current reference advertisement, ls-refs takes in parameters > +which can be used to limit the refs sent from the server. > + > +Ls-ref takes in the following parameters wraped in packet-lines: > + > + symrefs: In addition to the object pointed by it, show the underlying > + ref pointed by it when showing a symbolic ref. > + peel: Show peeled tags. > + ref-pattern : When specified, only references matching the > + given patterns are displayed. What kind of pattern matching is allowed here? strictly prefix only, or globbing, regexes? Is there a given grammar to follow? Maybe a link to the git glossary is or somewhere else might be fine. Seeing that we do wildmatch() down there (as opposed to regexes), I wonder if it provides an entry for a denial of service attack, by crafting a pattern that is very expensive for the server to compute but cheap to ask for from a client. (c.f. 94da9193a6 (grep: add support for PCRE v2, 2017-06-01, but that is regexes!) > +The output of ls-refs is as follows: > + > + output = *ref > + flush-pkt > + ref = PKT-LINE((tip | peeled) LF) > + tip = obj-id SP refname (SP symref-target) > + peeled = obj-id SP refname "^{}" > + > + symref = PKT-LINE("symref" SP symbolic-ref SP resolved-ref LF) > + shallow = PKT-LINE("shallow" SP obj-id LF) > diff --git a/Makefile b/Makefile > index 5f3b5fe8b..152a73bec 100644 > --- a/Makefile > +++ b/Makefile > @@ -820,6 +820,7 @@ LIB_OBJS += list-objects-filter-options.o > LIB_OBJS += ll-merge.o > LIB_OBJS += lockfile.o > LIB_OBJS += log-tree.o > +LIB_OBJS += ls-refs.o > LIB_OBJS += mailinfo.o > LIB_OBJS += mailmap.o > LIB_OBJS += match-trees.o > diff --git a/ls-refs.c b/ls-refs.c > new file mode 100644 > index 000000000..ac4904a40 > --- /dev/null > +++ b/ls-refs.c > @@ -0,0 +1,97 @@ > +#include "cache.h" > +#include "repository.h" > +#include "refs.h" > +#include "remote.h" > +#include "argv-array.h" > +#include "ls-refs.h" > +#include "pkt-line.h" > + > +struct ls_refs_data { > + unsigned peel; > + unsigned symrefs; > + struct argv_array patterns; > +}; > + > +/* > + * Check if one of the patterns matches the tail part of the ref. > + * If no patterns were provided, all refs match. > + */ > +static int ref_match(const struct argv_array *patterns, const char *refname) > +{ > + char *pathbuf; > + int i; > + > + if (!patterns->argc) > + return 1; /* no restriction */ > + > + pathbuf = xstrfmt("/%s", refname); > + for (i = 0; i < patterns->argc; i++) { > + if (!wildmatch(patterns->argv[i], pathbuf, 0)) { > + free(pathbuf); > + return 1; > + } > + } > + free(pathbuf); > + return 0; > +} > + > +static int send_ref(const char *refname, const struct object_id *oid, > + int flag, void *cb_data) > +{ > + struct ls_refs_data *data = cb_data; > + const char *refname_nons = strip_namespace(refname); > + struct strbuf refline = STRBUF_INIT; > + > + if (!ref_match(&data->patterns, refname)) > + return 0; > + > + strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons); > + if (data->symrefs && flag & REF_ISSYMREF) { > + struct object_id unused; > + const char *symref_target = resolve_ref_unsafe(refname, 0, > + &unused, > + &flag); > + > + if (!symref_target) > + die("'%s' is a symref but it is not?", refname); > + > + strbuf_addf(&refline, " %s", symref_target); > + } > + > + strbuf_addch(&refline, '\n'); > + > + packet_write(1, refline.buf, refline.len); > + if (data->peel) { > + struct object_id peeled; > + if (!peel_ref(refname, &peeled)) > + packet_write_fmt(1, "%s %s^{}\n", oid_to_hex(&peeled), > + refname_nons); > + } > + > + strbuf_release(&refline); > + return 0; > +} > + > +int ls_refs(struct repository *r, struct argv_array *keys, struct argv_array *args) > +{ > + int i; > + struct ls_refs_data data = { 0, 0, ARGV_ARRAY_INIT }; > + > + for (i = 0; i < args->argc; i++) { > + const char *arg = args->argv[i]; > + const char *out; > + > + if (!strcmp("peel", arg)) > + data.peel = 1; > + else if (!strcmp("symrefs", arg)) > + data.symrefs = 1; > + else if (skip_prefix(arg, "ref-pattern ", &out)) > + argv_array_pushf(&data.patterns, "*/%s", out); > + } > + > + head_ref_namespaced(send_ref, &data); > + for_each_namespaced_ref(send_ref, &data); > + packet_flush(1); > + argv_array_clear(&data.patterns); > + return 0; > +} > diff --git a/ls-refs.h b/ls-refs.h > new file mode 100644 > index 000000000..9e4c57bfe > --- /dev/null > +++ b/ls-refs.h > @@ -0,0 +1,9 @@ > +#ifndef LS_REFS_H > +#define LS_REFS_H > + > +struct repository; > +struct argv_array; > +extern int ls_refs(struct repository *r, struct argv_array *keys, > + struct argv_array *args); > + > +#endif /* LS_REFS_H */ > diff --git a/serve.c b/serve.c > index da8127775..88d548410 100644 > --- a/serve.c > +++ b/serve.c > @@ -4,6 +4,7 @@ > #include "pkt-line.h" > #include "version.h" > #include "argv-array.h" > +#include "ls-refs.h" > #include "serve.h" > > static int always_advertise(struct repository *r, > @@ -44,6 +45,7 @@ struct protocol_capability { > static struct protocol_capability capabilities[] = { > { "agent", agent_advertise, NULL }, > { "stateless-rpc", always_advertise, NULL }, > + { "ls-refs", always_advertise, ls_refs }, > }; > > static void advertise_capabilities(void) > -- > 2.15.1.620.gb9897f4670-goog >