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=-3.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI, 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 BE0EE20281 for ; Tue, 26 Sep 2017 18:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030721AbdIZSbs (ORCPT ); Tue, 26 Sep 2017 14:31:48 -0400 Received: from mail-pf0-f178.google.com ([209.85.192.178]:54311 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967715AbdIZSbq (ORCPT ); Tue, 26 Sep 2017 14:31:46 -0400 Received: by mail-pf0-f178.google.com with SMTP id d187so5945684pfg.11 for ; Tue, 26 Sep 2017 11:31:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=somM3ytgNaHKx5VXWy/INfIPILd+ItKLxFi/8NAhYmg=; b=vaz000avIozKCmDxq7TSijMSYVL9y+G07KP8vw4xu/+xpJPcadbC3Z87zV9I5JSnOW L5QoO0L53zRBglyC8NGD4VIP9OwbD+gKbr0v/Z5Fyg56PZnwd0tT6Vste5Q0NqQxR9Up fK56bCXbo9igZL7DAYUN0FOW9LCu+KGTxYcDD9spUC/tRbtcpY7Scv88snnzSHcwwzGg 1I3YAiGDo95lWRvekV2HJmV4IAj/VimvVMFAnR41H8ahWIXsbIFzfnhy+iX5aS16MIhL FM6K/enVVhzXDpAEtTqGhksQ6/Fj9DOquWE6hkIrk5cW/mV58sB8y0rC5K9wtAJKDH0X 4n7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=somM3ytgNaHKx5VXWy/INfIPILd+ItKLxFi/8NAhYmg=; b=kSh9qTKoQo3uQHSo6GY7ANkHv6NNerCq+viWjZ9Og+79mwU5PWs+Xfi02aP5Gob/Tz ywn0/d8tREbvBL9j5JXnGZb7+ScsR9e6DghdKqUtTmNuSL0oOY6Dmf3mxxQZuL6P87xw ucN7t0cWRT/Twcdxghn7UyphrpMY4/EM6XLJd2Mb+Ynk7L+M8nYotvtMJwKHUiRNM8WJ FWgrQ+eEYz7TfyqgaceteVvGUguLsZ75D685k367Ct+ntAOqBMkLKzIQFwztmoF6rqZo S1Hq4v5tJXda9k9z4atqRpgQi1tJRntl6TkSfguERCIWwh/WrKXPRXksZaUdWfFc91PY pLew== X-Gm-Message-State: AHPjjUiXkMlQT7a1q5kcvtqmRlX1lhfFEUI7gH6SPOGy1Cck2YdoCaa2 YMdI8lkL0wAu4tvxkhWMA86HBg== X-Google-Smtp-Source: AOwi7QAYy6Tc4ZETcT7TZ1VL7/ZWDwPV1iEx8SEmQJ71otXUkhKOf5FzHafKx81X71rIxlN47ErlpQ== X-Received: by 10.84.235.137 with SMTP id p9mr11359925plk.263.1506450705883; Tue, 26 Sep 2017 11:31:45 -0700 (PDT) Received: from google.com ([2620:0:100e:422:4905:123e:57ff:8ff9]) by smtp.gmail.com with ESMTPSA id a68sm17080987pfe.71.2017.09.26.11.31.44 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Tue, 26 Sep 2017 11:31:44 -0700 (PDT) Date: Tue, 26 Sep 2017 11:31:43 -0700 From: Brandon Williams To: Jonathan Tan Cc: git@vger.kernel.org, gitster@pobox.com Subject: Re: [PATCH v5] connect: in ref advertisement, shallows are last Message-ID: <20170926183143.GA144745@google.com> References: <20170921204501.32198-1-jonathantanmy@google.com> <20170926182147.73336-1-jonathantanmy@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170926182147.73336-1-jonathantanmy@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 09/26, Jonathan Tan wrote: > Currently, get_remote_heads() parses the ref advertisement in one loop, > allowing refs and shallow lines to intersperse, despite this not being > allowed by the specification. Refactor get_remote_heads() to use two > loops instead, enforcing that refs come first, and then shallows. > > This also makes it easier to teach get_remote_heads() to interpret other > lines in the ref advertisement, which will be done in a subsequent > patch. > > As part of this change, this patch interprets capabilities only on the > first line in the ref advertisement, printing a warning message when > encountering capabilities on other lines. > > Signed-off-by: Jonathan Tan > --- > Changes in v5: > - print warning when encountering capabilities on other lines instead > of ignoring them (also updated commit message) > - explicitly disallow refs of name "capabilities^{}" (except when it is > the only ref) > --- > connect.c | 183 +++++++++++++++++++++++++++++++++++++++----------------------- > 1 file changed, 117 insertions(+), 66 deletions(-) > > diff --git a/connect.c b/connect.c > index df56c0cbf..df65a3fc4 100644 > --- a/connect.c > +++ b/connect.c > @@ -11,6 +11,7 @@ > #include "string-list.h" > #include "sha1-array.h" > #include "transport.h" > +#include "strbuf.h" > > static char *server_capabilities; > static const char *parse_feature_value(const char *, const char *, int *); > @@ -107,6 +108,98 @@ static void annotate_refs_with_symref_info(struct ref *ref) > string_list_clear(&symref, 0); > } > > +/* > + * Read one line of a server's ref advertisement into packet_buffer. > + */ > +static int read_remote_ref(int in, char **src_buf, size_t *src_len, > + int *responded) > +{ > + int len = packet_read(in, src_buf, src_len, > + packet_buffer, sizeof(packet_buffer), > + PACKET_READ_GENTLE_ON_EOF | > + PACKET_READ_CHOMP_NEWLINE); > + const char *arg; > + if (len < 0) > + die_initial_contact(*responded); > + if (len > 4 && skip_prefix(packet_buffer, "ERR ", &arg)) > + die("remote error: %s", arg); > + > + *responded = 1; > + > + return len; > +} > + > +#define EXPECTING_FIRST_REF 0 > +#define EXPECTING_REF 1 > +#define EXPECTING_SHALLOW 2 > + > +static void process_capabilities(int *len) > +{ > + int nul_location = strlen(packet_buffer); > + if (nul_location == *len) > + return; > + server_capabilities = xstrdup(packet_buffer + nul_location + 1); > + *len = nul_location; > +} > + > +static int process_dummy_ref(void) > +{ > + static char *template; > + if (!template) > + template = xstrfmt("%040d capabilities^{}", 0); My only complaint is still here, I don't like the notion of hardcoding the 0's. Its much more future proof and less error prone to call parse_oid_hex and require that it matches null_oid. > + return !strcmp(packet_buffer, template); > +} > + > +static void check_no_capabilities(int len) > +{ > + if (strlen(packet_buffer) != len) > + warning("Ignoring capabilities after first line '%s'", > + packet_buffer + strlen(packet_buffer)); > +} > + > +static int process_ref(int len, struct ref ***list, unsigned int flags, > + struct oid_array *extra_have) > +{ > + struct object_id old_oid; > + const char *name; > + > + if (parse_oid_hex(packet_buffer, &old_oid, &name)) > + return 0; > + if (*name != ' ') > + return 0; > + name++; > + > + if (extra_have && !strcmp(name, ".have")) { > + oid_array_append(extra_have, &old_oid); > + } else if (!strcmp(name, "capabilities^{}")) { > + die("protocol error: unexpected capabilities^{}"); > + } else if (check_ref(name, flags)) { > + struct ref *ref = alloc_ref(name); > + oidcpy(&ref->old_oid, &old_oid); > + **list = ref; > + *list = &ref->next; > + } > + check_no_capabilities(len); > + return 1; > +} > + > +static int process_shallow(int len, struct oid_array *shallow_points) > +{ > + const char *arg; > + struct object_id old_oid; > + > + if (!skip_prefix(packet_buffer, "shallow ", &arg)) > + return 0; > + > + if (get_oid_hex(arg, &old_oid)) > + die("protocol error: expected shallow sha-1, got '%s'", arg); > + if (!shallow_points) > + die("repository on the other end cannot be shallow"); > + oid_array_append(shallow_points, &old_oid); > + check_no_capabilities(len); > + return 1; > +} > + > /* > * Read all the refs from the other end > */ > @@ -123,76 +216,34 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len, > * willing to talk to us. A hang-up before seeing any > * response does not necessarily mean an ACL problem, though. > */ > - int saw_response; > - int got_dummy_ref_with_capabilities_declaration = 0; > + int responded = 0; > + int len; > + int state = EXPECTING_FIRST_REF; > > *list = NULL; > - for (saw_response = 0; ; saw_response = 1) { > - struct ref *ref; > - struct object_id old_oid; > - char *name; > - int len, name_len; > - char *buffer = packet_buffer; > - const char *arg; > - > - len = packet_read(in, &src_buf, &src_len, > - packet_buffer, sizeof(packet_buffer), > - PACKET_READ_GENTLE_ON_EOF | > - PACKET_READ_CHOMP_NEWLINE); > - if (len < 0) > - die_initial_contact(saw_response); > - > - if (!len) > - break; > - > - if (len > 4 && skip_prefix(buffer, "ERR ", &arg)) > - die("remote error: %s", arg); > - > - if (len == GIT_SHA1_HEXSZ + strlen("shallow ") && > - skip_prefix(buffer, "shallow ", &arg)) { > - if (get_oid_hex(arg, &old_oid)) > - die("protocol error: expected shallow sha-1, got '%s'", arg); > - if (!shallow_points) > - die("repository on the other end cannot be shallow"); > - oid_array_append(shallow_points, &old_oid); > - continue; > - } > - > - if (len < GIT_SHA1_HEXSZ + 2 || get_oid_hex(buffer, &old_oid) || > - buffer[GIT_SHA1_HEXSZ] != ' ') > - die("protocol error: expected sha/ref, got '%s'", buffer); > - name = buffer + GIT_SHA1_HEXSZ + 1; > > - name_len = strlen(name); > - if (len != name_len + GIT_SHA1_HEXSZ + 1) { > - free(server_capabilities); > - server_capabilities = xstrdup(name + name_len + 1); > - } > - > - if (extra_have && !strcmp(name, ".have")) { > - oid_array_append(extra_have, &old_oid); > - continue; > - } > - > - if (!strcmp(name, "capabilities^{}")) { > - if (saw_response) > - die("protocol error: unexpected capabilities^{}"); > - if (got_dummy_ref_with_capabilities_declaration) > - die("protocol error: multiple capabilities^{}"); > - got_dummy_ref_with_capabilities_declaration = 1; > - continue; > + while ((len = read_remote_ref(in, &src_buf, &src_len, &responded))) { > + switch (state) { > + case EXPECTING_FIRST_REF: > + process_capabilities(&len); > + if (process_dummy_ref()) { > + state = EXPECTING_SHALLOW; > + break; > + } > + state = EXPECTING_REF; > + /* fallthrough */ > + case EXPECTING_REF: > + if (process_ref(len, &list, flags, extra_have)) > + break; > + state = EXPECTING_SHALLOW; > + /* fallthrough */ > + case EXPECTING_SHALLOW: > + if (process_shallow(len, shallow_points)) > + break; > + die("protocol error: unexpected '%s'", packet_buffer); > + default: > + die("unexpected state %d", state); > } > - > - if (!check_ref(name, flags)) > - continue; > - > - if (got_dummy_ref_with_capabilities_declaration) > - die("protocol error: unexpected ref after capabilities^{}"); > - > - ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1); > - oidcpy(&ref->old_oid, &old_oid); > - *list = ref; > - list = &ref->next; > } > > annotate_refs_with_symref_info(*orig_list); > -- > 2.14.1.821.g8fa685d3b7-goog > -- Brandon Williams