From b9ea214795b89e0455bbe92fab5d30d1f3a4cc6d Mon Sep 17 00:00:00 2001 From: Taylor Blau Date: Fri, 31 Jul 2020 16:26:26 -0400 Subject: [PATCH 1/4] list_objects_filter_options: introduce 'list_object_filter_config_name' In a subsequent commit, we will add configuration options that are specific to each kind of object filter, in which case it is handy to have a function that translates between 'enum list_objects_filter_choice' and an appropriate configuration-friendly string. Signed-off-by: Taylor Blau Acked-by: Jeff King Signed-off-by: Junio C Hamano --- list-objects-filter-options.c | 23 +++++++++++++++++++++++ list-objects-filter-options.h | 6 ++++++ 2 files changed, 29 insertions(+) diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c index 3553ad7b0a..92b408c0c8 100644 --- a/list-objects-filter-options.c +++ b/list-objects-filter-options.c @@ -15,6 +15,29 @@ static int parse_combine_filter( const char *arg, struct strbuf *errbuf); +const char *list_object_filter_config_name(enum list_objects_filter_choice c) +{ + switch (c) { + case LOFC_DISABLED: + /* we have no name for "no filter at all" */ + break; + case LOFC_BLOB_NONE: + return "blob:none"; + case LOFC_BLOB_LIMIT: + return "blob:limit"; + case LOFC_TREE_DEPTH: + return "tree"; + case LOFC_SPARSE_OID: + return "sparse:oid"; + case LOFC_COMBINE: + return "combine"; + case LOFC__COUNT: + /* not a real filter type; just the count of all filters */ + break; + } + BUG("list_object_filter_choice_name: invalid argument '%d'", c); +} + /* * Parse value of the argument to the "filter" keyword. * On the command line this looks like: diff --git a/list-objects-filter-options.h b/list-objects-filter-options.h index 73fffa4ad7..01767c3c96 100644 --- a/list-objects-filter-options.h +++ b/list-objects-filter-options.h @@ -17,6 +17,12 @@ enum list_objects_filter_choice { LOFC__COUNT /* must be last */ }; +/* + * Returns a configuration key suitable for describing the given object filter, + * e.g.: "blob:none", "combine", etc. + */ +const char *list_object_filter_config_name(enum list_objects_filter_choice c); + struct list_objects_filter_options { /* * 'filter_spec' is the raw argument value given on the command line From 6dd3456a8ccbad6a0a6a31bc7192025617114243 Mon Sep 17 00:00:00 2001 From: Taylor Blau Date: Mon, 3 Aug 2020 14:00:10 -0400 Subject: [PATCH 2/4] upload-pack.c: allow banning certain object filter(s) Git clients may ask the server for a partial set of objects, where the set of objects being requested is refined by one or more object filters. Server administrators can configure 'git upload-pack' to allow or ban these filters by setting the 'uploadpack.allowFilter' variable to 'true' or 'false', respectively. However, administrators using bitmaps may wish to allow certain kinds of object filters, but ban others. Specifically, they may wish to allow object filters that can be optimized by the use of bitmaps, while rejecting other object filters which aren't and represent a perceived performance degradation (as well as an increased load factor on the server). Allow configuring 'git upload-pack' to support object filters on a case-by-case basis by introducing two new configuration variables: - 'uploadpackfilter.allow' - 'uploadpackfilter..allow' where '' may be one of 'blobNone', 'blobLimit', 'tree', and so on. Setting the second configuration variable for any valid value of '' explicitly allows or disallows restricting that kind of object filter. If a client requests the object filter and the respective configuration value is not set, 'git upload-pack' will default to the value of 'uploadpackfilter.allow', which itself defaults to 'true' to maintain backwards compatibility. Note that this differs from 'uploadpack.allowfilter', which controls whether or not the 'filter' capability is advertised. Helped-by: Jeff King Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano --- Documentation/config/uploadpack.txt | 12 ++++ t/t5616-partial-clone.sh | 24 ++++++++ upload-pack.c | 86 +++++++++++++++++++++++++++++ 3 files changed, 122 insertions(+) diff --git a/Documentation/config/uploadpack.txt b/Documentation/config/uploadpack.txt index ed1c835695..fffe8ac648 100644 --- a/Documentation/config/uploadpack.txt +++ b/Documentation/config/uploadpack.txt @@ -57,6 +57,18 @@ uploadpack.allowFilter:: If this option is set, `upload-pack` will support partial clone and partial fetch object filtering. +uploadpackfilter.allow:: + Provides a default value for unspecified object filters (see: the + below configuration variable). + Defaults to `true`. + +uploadpackfilter..allow:: + Explicitly allow or ban the object filter corresponding to + ``, where `` may be one of: `blob:none`, + `blob:limit`, `tree`, `sparse:oid`, or `combine`. If using + combined filters, both `combine` and all of the nested filter + kinds must be allowed. Defaults to `uploadpackfilter.allow`. + uploadpack.allowRefInWant:: If this option is set, `upload-pack` will support the `ref-in-want` feature of the protocol version 2 `fetch` command. This feature diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh index 8a27452a51..1fff4ff3a9 100755 --- a/t/t5616-partial-clone.sh +++ b/t/t5616-partial-clone.sh @@ -235,6 +235,30 @@ test_expect_success 'implicitly construct combine: filter with repeated flags' ' test_cmp unique_types.expected unique_types.actual ' +test_expect_success 'upload-pack fails banned object filters' ' + test_config -C srv.bare uploadpackfilter.blob:none.allow false && + test_must_fail ok=sigpipe git clone --no-checkout --filter=blob:none \ + "file://$(pwd)/srv.bare" pc3 2>err && + grep "filter '\''blob:none'\'' not supported" err +' + +test_expect_success 'upload-pack fails banned combine object filters' ' + test_config -C srv.bare uploadpackfilter.allow false && + test_config -C srv.bare uploadpackfilter.combine.allow true && + test_config -C srv.bare uploadpackfilter.tree.allow true && + test_config -C srv.bare uploadpackfilter.blob:none.allow false && + test_must_fail ok=sigpipe git clone --no-checkout --filter=tree:1 \ + --filter=blob:none "file://$(pwd)/srv.bare" pc3 2>err && + grep "filter '\''blob:none'\'' not supported" err +' + +test_expect_success 'upload-pack fails banned object filters with fallback' ' + test_config -C srv.bare uploadpackfilter.allow false && + test_must_fail ok=sigpipe git clone --no-checkout --filter=blob:none \ + "file://$(pwd)/srv.bare" pc3 2>err && + grep "filter '\''blob:none'\'' not supported" err +' + test_expect_success 'partial clone fetches blobs pointed to by refs even if normally filtered out' ' rm -rf src dst && git init src && diff --git a/upload-pack.c b/upload-pack.c index 39d0cf00be..5a9d767a12 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -88,6 +88,7 @@ struct upload_pack_data { enum allow_uor allow_uor; struct list_objects_filter_options filter_options; + struct string_list allowed_filters; struct packet_writer writer; @@ -103,6 +104,7 @@ struct upload_pack_data { unsigned no_progress : 1; unsigned use_include_tag : 1; unsigned allow_filter : 1; + unsigned allow_filter_fallback : 1; unsigned done : 1; /* v2 only */ unsigned allow_ref_in_want : 1; /* v2 only */ @@ -120,6 +122,7 @@ static void upload_pack_data_init(struct upload_pack_data *data) struct string_list deepen_not = STRING_LIST_INIT_DUP; struct string_list uri_protocols = STRING_LIST_INIT_DUP; struct object_array extra_edge_obj = OBJECT_ARRAY_INIT; + struct string_list allowed_filters = STRING_LIST_INIT_DUP; memset(data, 0, sizeof(*data)); data->symref = symref; @@ -131,6 +134,8 @@ static void upload_pack_data_init(struct upload_pack_data *data) data->deepen_not = deepen_not; data->uri_protocols = uri_protocols; data->extra_edge_obj = extra_edge_obj; + data->allowed_filters = allowed_filters; + data->allow_filter_fallback = 1; packet_writer_init(&data->writer, 1); data->keepalive = 5; @@ -147,6 +152,7 @@ static void upload_pack_data_clear(struct upload_pack_data *data) string_list_clear(&data->deepen_not, 0); object_array_clear(&data->extra_edge_obj); list_objects_filter_release(&data->filter_options); + string_list_clear(&data->allowed_filters, 1); free((char *)data->pack_objects_hook); } @@ -983,6 +989,56 @@ static int process_deepen_not(const char *line, struct string_list *deepen_not, return 0; } +NORETURN __attribute__((format(printf,2,3))) +static void send_err_and_die(struct upload_pack_data *data, + const char *fmt, ...) +{ + struct strbuf buf = STRBUF_INIT; + va_list ap; + + va_start(ap, fmt); + strbuf_vaddf(&buf, fmt, ap); + va_end(ap); + + packet_writer_error(&data->writer, "%s", buf.buf); + die("%s", buf.buf); +} + +static void check_one_filter(struct upload_pack_data *data, + struct list_objects_filter_options *opts) +{ + const char *key = list_object_filter_config_name(opts->choice); + struct string_list_item *item = string_list_lookup(&data->allowed_filters, + key); + int allowed; + + if (item) + allowed = (intptr_t)item->util; + else + allowed = data->allow_filter_fallback; + + if (!allowed) + send_err_and_die(data, "filter '%s' not supported", key); +} + +static void check_filter_recurse(struct upload_pack_data *data, + struct list_objects_filter_options *opts) +{ + size_t i; + + check_one_filter(data, opts); + if (opts->choice != LOFC_COMBINE) + return; + + for (i = 0; i < opts->sub_nr; i++) + check_filter_recurse(data, &opts->sub[i]); +} + +static void die_if_using_banned_filter(struct upload_pack_data *data) +{ + check_filter_recurse(data, &data->filter_options); +} + static void receive_needs(struct upload_pack_data *data, struct packet_reader *reader) { @@ -1013,6 +1069,7 @@ static void receive_needs(struct upload_pack_data *data, die("git upload-pack: filtering capability not negotiated"); list_objects_filter_die_if_populated(&data->filter_options); parse_list_objects_filter(&data->filter_options, arg); + die_if_using_banned_filter(data); continue; } @@ -1169,6 +1226,32 @@ static int find_symref(const char *refname, const struct object_id *oid, return 0; } +static int parse_object_filter_config(const char *var, const char *value, + struct upload_pack_data *data) +{ + struct strbuf buf = STRBUF_INIT; + const char *sub, *key; + size_t sub_len; + + if (parse_config_key(var, "uploadpackfilter", &sub, &sub_len, &key)) + return 0; + + if (!sub) { + if (!strcmp(key, "allow")) + data->allow_filter_fallback = git_config_bool(var, value); + return 0; + } + + strbuf_add(&buf, sub, sub_len); + + if (!strcmp(key, "allow")) + string_list_insert(&data->allowed_filters, buf.buf)->util = + (void *)(intptr_t)git_config_bool(var, value); + + strbuf_release(&buf); + return 0; +} + static int upload_pack_config(const char *var, const char *value, void *cb_data) { struct upload_pack_data *data = cb_data; @@ -1208,6 +1291,8 @@ static int upload_pack_config(const char *var, const char *value, void *cb_data) return git_config_string(&data->pack_objects_hook, var, value); } + parse_object_filter_config(var, value, data); + return parse_hide_refs_config(var, value, "uploadpack"); } @@ -1388,6 +1473,7 @@ static void process_args(struct packet_reader *request, if (data->allow_filter && skip_prefix(arg, "filter ", &p)) { list_objects_filter_die_if_populated(&data->filter_options); parse_list_objects_filter(&data->filter_options, p); + die_if_using_banned_filter(data); continue; } From 5b01a4e8ff19fa9797a67b53df2db0a1a574fe81 Mon Sep 17 00:00:00 2001 From: Taylor Blau Date: Mon, 3 Aug 2020 14:00:17 -0400 Subject: [PATCH 3/4] upload-pack.c: introduce 'uploadpackfilter.tree.maxDepth' In b79cf959b2 (upload-pack.c: allow banning certain object filter(s), 2020-02-26), we introduced functionality to disallow certain object filters from being chosen from within 'git upload-pack'. Traditionally, administrators use this functionality to disallow filters that are known to perform slowly, for e.g., those that do not have bitmap-level filtering. In the past, the '--filter=tree:' was one such filter that does not have bitmap-level filtering support, and so was likely to be banned by administrators. However, in the previous couple of commits, we introduced bitmap-level filtering for the case when 'n' is equal to '0', i.e., as if we had a '--filter=tree:none' choice. While it would be sufficient to simply write $ git config uploadpackfilter.tree.allow true (since it would allow all values of 'n'), we would like to be able to allow this filter for certain values of 'n', i.e., those no greater than some pre-specified maximum. In order to do this, introduce a new configuration key, as follows: $ git config uploadpackfilter.tree.maxDepth where '' specifies the maximum allowed value of 'n' in the filter 'tree:n'. Administrators who wish to allow for only the value '0' can write: $ git config uploadpackfilter.tree.allow true $ git config uploadpackfilter.tree.maxDepth 0 which allows '--filter=tree:0', but no other values. Signed-off-by: Taylor Blau Acked-by: Jeff King Signed-off-by: Junio C Hamano --- Documentation/config/uploadpack.txt | 6 ++++++ t/t5616-partial-clone.sh | 9 +++++++++ upload-pack.c | 18 ++++++++++++++++++ 3 files changed, 33 insertions(+) diff --git a/Documentation/config/uploadpack.txt b/Documentation/config/uploadpack.txt index fffe8ac648..ee7b3ac94f 100644 --- a/Documentation/config/uploadpack.txt +++ b/Documentation/config/uploadpack.txt @@ -69,6 +69,12 @@ uploadpackfilter..allow:: combined filters, both `combine` and all of the nested filter kinds must be allowed. Defaults to `uploadpackfilter.allow`. +uploadpackfilter.tree.maxDepth:: + Only allow `--filter=tree=` when `n` is no more than the value of + `uploadpackfilter.tree.maxDepth`. If set, this also implies + `uploadpackfilter.tree.allow=true`, unless this configuration + variable had already been set. Has no effect if unset. + uploadpack.allowRefInWant:: If this option is set, `upload-pack` will support the `ref-in-want` feature of the protocol version 2 `fetch` command. This feature diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh index 1fff4ff3a9..4247102b00 100755 --- a/t/t5616-partial-clone.sh +++ b/t/t5616-partial-clone.sh @@ -259,6 +259,15 @@ test_expect_success 'upload-pack fails banned object filters with fallback' ' grep "filter '\''blob:none'\'' not supported" err ' +test_expect_success 'upload-pack limits tree depth filters' ' + test_config -C srv.bare uploadpackfilter.allow false && + test_config -C srv.bare uploadpackfilter.tree.allow true && + test_config -C srv.bare uploadpackfilter.tree.maxDepth 0 && + test_must_fail ok=sigpipe git clone --no-checkout --filter=tree:1 \ + "file://$(pwd)/srv.bare" pc3 2>err && + grep "tree filter allows max depth 0, but got 1" err +' + test_expect_success 'partial clone fetches blobs pointed to by refs even if normally filtered out' ' rm -rf src dst && git init src && diff --git a/upload-pack.c b/upload-pack.c index 5a9d767a12..fb9c7e1315 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -105,6 +105,7 @@ struct upload_pack_data { unsigned use_include_tag : 1; unsigned allow_filter : 1; unsigned allow_filter_fallback : 1; + unsigned long tree_filter_max_depth; unsigned done : 1; /* v2 only */ unsigned allow_ref_in_want : 1; /* v2 only */ @@ -136,6 +137,7 @@ static void upload_pack_data_init(struct upload_pack_data *data) data->extra_edge_obj = extra_edge_obj; data->allowed_filters = allowed_filters; data->allow_filter_fallback = 1; + data->tree_filter_max_depth = ULONG_MAX; packet_writer_init(&data->writer, 1); data->keepalive = 5; @@ -1019,6 +1021,13 @@ static void check_one_filter(struct upload_pack_data *data, if (!allowed) send_err_and_die(data, "filter '%s' not supported", key); + + if (opts->choice == LOFC_TREE_DEPTH && + opts->tree_exclude_depth > data->tree_filter_max_depth) + send_err_and_die(data, + "tree filter allows max depth %lu, but got %lu", + data->tree_filter_max_depth, + opts->tree_exclude_depth); } static void check_filter_recurse(struct upload_pack_data *data, @@ -1247,6 +1256,15 @@ static int parse_object_filter_config(const char *var, const char *value, if (!strcmp(key, "allow")) string_list_insert(&data->allowed_filters, buf.buf)->util = (void *)(intptr_t)git_config_bool(var, value); + else if (!strcmp(buf.buf, "tree") && !strcmp(key, "maxdepth")) { + if (!value) { + strbuf_release(&buf); + return config_error_nonbool(var); + } + string_list_insert(&data->allowed_filters, buf.buf)->util = + (void *)(intptr_t)1; + data->tree_filter_max_depth = git_config_ulong(var, value); + } strbuf_release(&buf); return 0; From 6cc275ea56e21537f480443fc8fd36f34c8b92cd Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 5 Aug 2020 04:42:40 -0400 Subject: [PATCH 4/4] t5616: use test_i18ngrep for upload-pack errors The tests added to t5616 in 6dd3456a8c (upload-pack.c: allow banning certain object filter(s), 2020-08-03) can fail racily, but only with GETTEXT_POISON enabled. The tests in question look something like this: test_must_fail ok=sigpipe git clone --filter=blob:none ... 2>err && grep "filter blob:none not supported' err The remote upload-pack process writes that error message both as an ERR packet, but also via a die() message. In theory we should see the message twice in the "err" file. The client relays the message from the packet to its stderr (with a "remote error:" prefix), and because this is a local-system clone, upload-pack's stderr goes to the same place. But because clone may be writing to the pipe when upload-pack calls die(), it may get SIGPIPE and fail to relay the message. That's why we need our "ok=sigpipe" trick. But our grep should still work reliably in that case. Either: - we got SIGPIPE on the client, which means upload-pack completed its die(), and we'll see that version of the message. - the client didn't get SIGPIPE, and so it successfully relays the message. In theory we'd see both copies of the message in the second case. But now always! As soon as the client sees ERR, it exits and we run grep. But we have no guarantee that the upload-pack process has exited at this point, or even written its die() message. We might only see the client version of the message. Normally that's OK. We only need to see one or the other to pass the test. But now consider GETTEXT_POISON. upload-pack doesn't translate the die() message nor the ERR packet. But once the client receives it, it calls: die(_("remote error: %s"), buffer + 4); That message _is_ marked for translation. Normally we'd just replace the "remote error:" portion of it, but in GETTEXT_POISON mode, we replace the whole thing with "# GETTEXT POISON #" and don't include the "%s" part at all. So the whole text from the ERR packet is dropped, and so we may racily see a test failure if upload-pack's die() call wasn't yet written. We can fix it by using test_i18ngrep, which just makes this grep a noop in the poison mode. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- t/t5616-partial-clone.sh | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh index 4247102b00..9164ad3e63 100755 --- a/t/t5616-partial-clone.sh +++ b/t/t5616-partial-clone.sh @@ -239,7 +239,7 @@ test_expect_success 'upload-pack fails banned object filters' ' test_config -C srv.bare uploadpackfilter.blob:none.allow false && test_must_fail ok=sigpipe git clone --no-checkout --filter=blob:none \ "file://$(pwd)/srv.bare" pc3 2>err && - grep "filter '\''blob:none'\'' not supported" err + test_i18ngrep "filter '\''blob:none'\'' not supported" err ' test_expect_success 'upload-pack fails banned combine object filters' ' @@ -249,14 +249,14 @@ test_expect_success 'upload-pack fails banned combine object filters' ' test_config -C srv.bare uploadpackfilter.blob:none.allow false && test_must_fail ok=sigpipe git clone --no-checkout --filter=tree:1 \ --filter=blob:none "file://$(pwd)/srv.bare" pc3 2>err && - grep "filter '\''blob:none'\'' not supported" err + test_i18ngrep "filter '\''blob:none'\'' not supported" err ' test_expect_success 'upload-pack fails banned object filters with fallback' ' test_config -C srv.bare uploadpackfilter.allow false && test_must_fail ok=sigpipe git clone --no-checkout --filter=blob:none \ "file://$(pwd)/srv.bare" pc3 2>err && - grep "filter '\''blob:none'\'' not supported" err + test_i18ngrep "filter '\''blob:none'\'' not supported" err ' test_expect_success 'upload-pack limits tree depth filters' ' @@ -265,7 +265,7 @@ test_expect_success 'upload-pack limits tree depth filters' ' test_config -C srv.bare uploadpackfilter.tree.maxDepth 0 && test_must_fail ok=sigpipe git clone --no-checkout --filter=tree:1 \ "file://$(pwd)/srv.bare" pc3 2>err && - grep "tree filter allows max depth 0, but got 1" err + test_i18ngrep "tree filter allows max depth 0, but got 1" err ' test_expect_success 'partial clone fetches blobs pointed to by refs even if normally filtered out' '