diff mbox series

[8/8] upload-pack: send part of packfile response as uri

Message ID 2cfee363873736d9ff73cd38d96f3533bb49c904.1590789428.git.jonathantanmy@google.com (mailing list archive)
State New, archived
Headers show
Series CDN offloading update | expand

Commit Message

Jonathan Tan May 29, 2020, 10:30 p.m. UTC
Teach upload-pack to send part of its packfile response as URIs.

An administrator may configure a repository with one or more
"uploadpack.blobpackfileuri" lines, each line containing an OID, a pack
hash, and a URI. A client may configure fetch.uriprotocols to be a
comma-separated list of protocols that it is willing to use to fetch
additional packfiles - this list will be sent to the server. Whenever an
object with one of those OIDs would appear in the packfile transmitted
by upload-pack, the server may exclude that object, and instead send the
URI. The client will then download the packs referred to by those URIs
before performing the connectivity check.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/pack-objects.c |  76 ++++++++++++++++++++++++++++
 fetch-pack.c           | 110 +++++++++++++++++++++++++++++++++++++++--
 t/t5702-protocol-v2.sh |  88 +++++++++++++++++++++++++++++++++
 upload-pack.c          |  80 +++++++++++++++++++++++++++---
 4 files changed, 344 insertions(+), 10 deletions(-)

Comments

Junio C Hamano May 31, 2020, 4:59 p.m. UTC | #1
Jonathan Tan <jonathantanmy@google.com> writes:

> diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
> index 8da65e60de..3ea9345e6f 100755
> + ...
> +	GIT_TEST_SIDEBAND_ALL=1 \
> +	test_must_fail git -c protocol.version=2 \
> +		-c fetch.uriprotocols=http,https \
> +		clone "$HTTPD_URL/smart/http_parent" http_child 2>err &&
> +	test_i18ngrep "pack downloaded from.*does not match expected hash" err

I haven't really read the later parts of this series, but I noticed
that this triggers a test-lint check.  I'll be adding the following
fixup in the meantime before continuing today's integration run.

Thanks.

-- >8 --
Subject: [PATCH] fixup! upload-pack: send part of packfile response as uri

---
 t/t5702-protocol-v2.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 041e78a88f..53bda39fb7 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -829,8 +829,8 @@ test_expect_success 'fetching with valid packfile URI but invalid hash fails' '
 		"uploadpack.blobpackfileuri" \
 		"$(cat objh) $(cat objh) $HTTPD_URL/dumb/mypack-$(cat packh).pack" &&
 
-	GIT_TEST_SIDEBAND_ALL=1 \
-	test_must_fail git -c protocol.version=2 \
+	test_must_fail env GIT_TEST_SIDEBAND_ALL=1 \
+		git -c protocol.version=2 \
 		-c fetch.uriprotocols=http,https \
 		clone "$HTTPD_URL/smart/http_parent" http_child 2>err &&
 	test_i18ngrep "pack downloaded from.*does not match expected hash" err
Junio C Hamano May 31, 2020, 5:35 p.m. UTC | #2
Jonathan Tan <jonathantanmy@google.com> writes:

>  static void create_pack_file(const struct object_array *have_obj,
>  			     const struct object_array *want_obj,
> -			     struct list_objects_filter_options *filter_options)
> +			     struct list_objects_filter_options *filter_options,
> +			     const struct string_list *uri_protocols)
>  {

I wanted to see why you rebased on top of 'next' to see possible
interactions with topics in-flight, and I found out that this series
was trivial to rebase on 'master'.

The codebase however is moving in the direction to reduce the number
of parameters this function takes, and the above change does not
play well with the cc/upload-pack-data-2 topic that cleans up the
code around this area.

Can you help review cc/upload-pack-data and cc/upload-pack-data-2
topics, as you'd eventually be basing your topic on top of the
result of merging these two clean-up topics to 'master'?  The former
is already in 'next' after Peff's review, and after finding nothing
glaringly wrong in it, I am not so worried about it, but the latter
may benefit from an extra set of eyes.

Thanks.
Jonathan Nieder June 1, 2020, 8 p.m. UTC | #3
Jonathan Tan wrote:

> +++ b/builtin/pack-objects.c
[...]
> @@ -192,6 +227,11 @@ static void create_pack_file(const struct object_array *have_obj,
>  					 spec);
>  		}
>  	}
> +	if (uri_protocols) {
> +		for (i = 0; i < uri_protocols->nr; i++)
> +			argv_array_pushf(&pack_objects.args, "--uri-protocol=%s",
> +					 uri_protocols->items[0].string);

Should this be items[i]?

Thanks,
Jonathan
Jonathan Tan June 1, 2020, 11:20 p.m. UTC | #4
> Jonathan Tan <jonathantanmy@google.com> writes:
> 
> >  static void create_pack_file(const struct object_array *have_obj,
> >  			     const struct object_array *want_obj,
> > -			     struct list_objects_filter_options *filter_options)
> > +			     struct list_objects_filter_options *filter_options,
> > +			     const struct string_list *uri_protocols)
> >  {
> 
> I wanted to see why you rebased on top of 'next' to see possible
> interactions with topics in-flight, and I found out that this series
> was trivial to rebase on 'master'.
> 
> The codebase however is moving in the direction to reduce the number
> of parameters this function takes, and the above change does not
> play well with the cc/upload-pack-data-2 topic that cleans up the
> code around this area.
> 
> Can you help review cc/upload-pack-data and cc/upload-pack-data-2
> topics, as you'd eventually be basing your topic on top of the
> result of merging these two clean-up topics to 'master'?  The former
> is already in 'next' after Peff's review, and after finding nothing
> glaringly wrong in it, I am not so worried about it, but the latter
> may benefit from an extra set of eyes.
> 
> Thanks.

OK - I'll take a look tomorrow.
diff mbox series

Patch

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c5b433a23f..7016b28485 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -117,6 +117,8 @@  static unsigned long window_memory_limit = 0;
 
 static struct list_objects_filter_options filter_options;
 
+static struct string_list uri_protocols = STRING_LIST_INIT_NODUP;
+
 enum missing_action {
 	MA_ERROR = 0,      /* fail if any missing objects are encountered */
 	MA_ALLOW_ANY,      /* silently allow ALL missing objects */
@@ -125,6 +127,15 @@  enum missing_action {
 static enum missing_action arg_missing_action;
 static show_object_fn fn_show_object;
 
+struct configured_exclusion {
+	struct oidmap_entry e;
+	char *pack_hash_hex;
+	char *uri;
+};
+static struct oidmap configured_exclusions;
+
+static struct oidset excluded_by_config;
+
 /*
  * stats
  */
@@ -969,6 +980,25 @@  static void write_reused_pack(struct hashfile *f)
 	unuse_pack(&w_curs);
 }
 
+static void write_excluded_by_configs(void)
+{
+	struct oidset_iter iter;
+	const struct object_id *oid;
+
+	oidset_iter_init(&excluded_by_config, &iter);
+	while ((oid = oidset_iter_next(&iter))) {
+		struct configured_exclusion *ex =
+			oidmap_get(&configured_exclusions, oid);
+
+		if (!ex)
+			BUG("configured exclusion wasn't configured");
+		write_in_full(1, ex->pack_hash_hex, strlen(ex->pack_hash_hex));
+		write_in_full(1, " ", 1);
+		write_in_full(1, ex->uri, strlen(ex->uri));
+		write_in_full(1, "\n", 1);
+	}
+}
+
 static const char no_split_warning[] = N_(
 "disabling bitmap writing, packs are split due to pack.packSizeLimit"
 );
@@ -1266,6 +1296,25 @@  static int want_object_in_pack(const struct object_id *oid,
 		}
 	}
 
+	if (uri_protocols.nr) {
+		struct configured_exclusion *ex =
+			oidmap_get(&configured_exclusions, oid);
+		int i;
+		const char *p;
+
+		if (ex) {
+			for (i = 0; i < uri_protocols.nr; i++) {
+				if (skip_prefix(ex->uri,
+						uri_protocols.items[i].string,
+						&p) &&
+				    *p == ':') {
+					oidset_insert(&excluded_by_config, oid);
+					return 0;
+				}
+			}
+		}
+	}
+
 	return 1;
 }
 
@@ -2864,6 +2913,29 @@  static int git_pack_config(const char *k, const char *v, void *cb)
 			    pack_idx_opts.version);
 		return 0;
 	}
+	if (!strcmp(k, "uploadpack.blobpackfileuri")) {
+		struct configured_exclusion *ex = xmalloc(sizeof(*ex));
+		const char *oid_end, *pack_end;
+		/*
+		 * Stores the pack hash. This is not a true object ID, but is
+		 * of the same form.
+		 */
+		struct object_id pack_hash;
+
+		if (parse_oid_hex(v, &ex->e.oid, &oid_end) ||
+		    *oid_end != ' ' ||
+		    parse_oid_hex(oid_end + 1, &pack_hash, &pack_end) ||
+		    *pack_end != ' ')
+			die(_("value of uploadpack.blobpackfileuri must be "
+			      "of the form '<object-hash> <pack-hash> <uri>' (got '%s')"), v);
+		if (oidmap_get(&configured_exclusions, &ex->e.oid))
+			die(_("object already configured in another "
+			      "uploadpack.blobpackfileuri (got '%s')"), v);
+		ex->pack_hash_hex = xcalloc(1, pack_end - oid_end);
+		memcpy(ex->pack_hash_hex, oid_end + 1, pack_end - oid_end - 1);
+		ex->uri = xstrdup(pack_end + 1);
+		oidmap_put(&configured_exclusions, ex);
+	}
 	return git_default_config(k, v, cb);
 }
 
@@ -3462,6 +3534,9 @@  int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			 N_("do not pack objects in promisor packfiles")),
 		OPT_BOOL(0, "delta-islands", &use_delta_islands,
 			 N_("respect islands during delta compression")),
+		OPT_STRING_LIST(0, "uri-protocol", &uri_protocols,
+				N_("protocol"),
+				N_("exclude any configured uploadpack.blobpackfileuri with this protocol")),
 		OPT_END(),
 	};
 
@@ -3650,6 +3725,7 @@  int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	}
 
 	trace2_region_enter("pack-objects", "write-pack-file", the_repository);
+	write_excluded_by_configs();
 	write_pack_file();
 	trace2_region_leave("pack-objects", "write-pack-file", the_repository);
 
diff --git a/fetch-pack.c b/fetch-pack.c
index 0a9a82bc46..9668c0b66e 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -38,6 +38,7 @@  static int server_supports_filtering;
 static struct shallow_lock shallow_lock;
 static const char *alternate_shallow_file;
 static struct strbuf fsck_msg_types = STRBUF_INIT;
+static struct string_list uri_protocols = STRING_LIST_INIT_DUP;
 
 /* Remember to update object flag allocation in object.h */
 #define COMPLETE	(1U << 0)
@@ -795,6 +796,7 @@  static void write_promisor_file(const char *keep_name,
 
 static int get_pack(struct fetch_pack_args *args,
 		    int xd[2], struct string_list *pack_lockfiles,
+		    int only_packfile,
 		    struct ref **sought, int nr_sought)
 {
 	struct async demux;
@@ -855,8 +857,15 @@  static int get_pack(struct fetch_pack_args *args,
 					"--keep=fetch-pack %"PRIuMAX " on %s",
 					(uintmax_t)getpid(), hostname);
 		}
-		if (args->check_self_contained_and_connected)
+		if (only_packfile && args->check_self_contained_and_connected)
 			argv_array_push(&cmd.args, "--check-self-contained-and-connected");
+		else
+			/*
+			 * We cannot perform any connectivity checks because
+			 * not all packs have been downloaded; let the caller
+			 * have this responsibility.
+			 */
+			args->check_self_contained_and_connected = 0;
 		/*
 		 * If we're obtaining the filename of a lockfile, we'll use
 		 * that filename to write a .promisor file with more
@@ -1068,7 +1077,7 @@  static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 		alternate_shallow_file = setup_temporary_shallow(si->shallow);
 	else
 		alternate_shallow_file = NULL;
-	if (get_pack(args, fd, pack_lockfiles, sought, nr_sought))
+	if (get_pack(args, fd, pack_lockfiles, 1, sought, nr_sought))
 		die(_("git fetch-pack: fetch failed."));
 
  all_done:
@@ -1222,6 +1231,26 @@  static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
 		warning("filtering not recognized by server, ignoring");
 	}
 
+	if (server_supports_feature("fetch", "packfile-uris", 0)) {
+		int i;
+		struct strbuf to_send = STRBUF_INIT;
+
+		for (i = 0; i < uri_protocols.nr; i++) {
+			const char *s = uri_protocols.items[i].string;
+
+			if (!strcmp(s, "https") || !strcmp(s, "http")) {
+				if (to_send.len)
+					strbuf_addch(&to_send, ',');
+				strbuf_addstr(&to_send, s);
+			}
+		}
+		if (to_send.len) {
+			packet_buf_write(&req_buf, "packfile-uris %s",
+					 to_send.buf);
+			strbuf_release(&to_send);
+		}
+	}
+
 	/* add wants */
 	add_wants(args->no_dependents, wants, &req_buf);
 
@@ -1444,6 +1473,21 @@  static void receive_wanted_refs(struct packet_reader *reader,
 		die(_("error processing wanted refs: %d"), reader->status);
 }
 
+static void receive_packfile_uris(struct packet_reader *reader,
+				  struct string_list *uris)
+{
+	process_section_header(reader, "packfile-uris", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		if (reader->pktlen < the_hash_algo->hexsz ||
+		    reader->line[the_hash_algo->hexsz] != ' ')
+			die("expected '<hash> <uri>', got: %s\n", reader->line);
+
+		string_list_append(uris, reader->line);
+	}
+	if (reader->status != PACKET_READ_DELIM)
+		die("expected DELIM");
+}
+
 enum fetch_state {
 	FETCH_CHECK_LOCAL = 0,
 	FETCH_SEND_REQUEST,
@@ -1477,6 +1521,8 @@  static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	struct fetch_negotiator negotiator_alloc;
 	struct fetch_negotiator *negotiator;
 	int seen_ack = 0;
+	struct string_list packfile_uris = STRING_LIST_INIT_DUP;
+	int i;
 
 	if (args->no_dependents) {
 		negotiator = NULL;
@@ -1570,9 +1616,12 @@  static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 			if (process_section_header(&reader, "wanted-refs", 1))
 				receive_wanted_refs(&reader, sought, nr_sought);
 
-			/* get the pack */
+			/* get the pack(s) */
+			if (process_section_header(&reader, "packfile-uris", 1))
+				receive_packfile_uris(&reader, &packfile_uris);
 			process_section_header(&reader, "packfile", 0);
-			if (get_pack(args, fd, pack_lockfiles, sought, nr_sought))
+			if (get_pack(args, fd, pack_lockfiles,
+				     !packfile_uris.nr, sought, nr_sought))
 				die(_("git fetch-pack: fetch failed."));
 			do_check_stateless_delimiter(args, &reader);
 
@@ -1583,8 +1632,53 @@  static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 		}
 	}
 
+	for (i = 0; i < packfile_uris.nr; i++) {
+		struct child_process cmd = CHILD_PROCESS_INIT;
+		char packname[GIT_MAX_HEXSZ + 1];
+		const char *uri = packfile_uris.items[i].string +
+			the_hash_algo->hexsz + 1;
+
+		argv_array_push(&cmd.args, "http-fetch");
+		argv_array_push(&cmd.args, "--packfile");
+		argv_array_push(&cmd.args, uri);
+		cmd.git_cmd = 1;
+		cmd.no_stdin = 1;
+		cmd.out = -1;
+		if (start_command(&cmd))
+			die("fetch-pack: unable to spawn http-fetch");
+
+		if (read_in_full(cmd.out, packname, 5) < 0 ||
+		    memcmp(packname, "keep\t", 5))
+			die("fetch-pack: expected keep then TAB at start of http-fetch output");
+
+		if (read_in_full(cmd.out, packname,
+				 the_hash_algo->hexsz + 1) < 0 ||
+		    packname[the_hash_algo->hexsz] != '\n')
+			die("fetch-pack: expected hash then LF at end of http-fetch output");
+
+		packname[the_hash_algo->hexsz] = '\0';
+
+		close(cmd.out);
+
+		if (finish_command(&cmd))
+			die("fetch-pack: unable to finish http-fetch");
+
+		if (memcmp(packfile_uris.items[i].string, packname,
+			   the_hash_algo->hexsz))
+			die("fetch-pack: pack downloaded from %s does not match expected hash %.*s",
+			    uri, (int) the_hash_algo->hexsz,
+			    packfile_uris.items[i].string);
+
+		string_list_append_nodup(pack_lockfiles,
+					 xstrfmt("%s/pack/pack-%s.keep",
+						 get_object_directory(),
+						 packname));
+	}
+	string_list_clear(&packfile_uris, 0);
+
 	if (negotiator)
 		negotiator->release(negotiator);
+
 	oidset_clear(&common);
 	return ref;
 }
@@ -1621,6 +1715,14 @@  static void fetch_pack_config(void)
 	git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
 	git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
 	git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
+	if (!uri_protocols.nr) {
+		char *str;
+
+		if (!git_config_get_string("fetch.uriprotocols", &str) && str) {
+			string_list_split(&uri_protocols, str, ',', -1);
+			free(str);
+		}
+	}
 
 	git_config(fetch_pack_config_cb, NULL);
 }
diff --git a/t/t5702-protocol-v2.sh b/t/t5702-protocol-v2.sh
index 8da65e60de..3ea9345e6f 100755
--- a/t/t5702-protocol-v2.sh
+++ b/t/t5702-protocol-v2.sh
@@ -795,6 +795,94 @@  test_expect_success 'when server does not send "ready", expect FLUSH' '
 	test_i18ngrep "expected no other sections to be sent after no .ready." err
 '
 
+configure_exclusion () {
+	git -C "$1" hash-object "$2" >objh &&
+	git -C "$1" pack-objects "$HTTPD_DOCUMENT_ROOT_PATH/mypack" <objh >packh &&
+	git -C "$1" config --add \
+		"uploadpack.blobpackfileuri" \
+		"$(cat objh) $(cat packh) $HTTPD_URL/dumb/mypack-$(cat packh).pack" &&
+	cat objh
+}
+
+test_expect_success 'part of packfile response provided as URI' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child log &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	echo my-blob >"$P/my-blob" &&
+	git -C "$P" add my-blob &&
+	echo other-blob >"$P/other-blob" &&
+	git -C "$P" add other-blob &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" my-blob >h &&
+	configure_exclusion "$P" other-blob >h2 &&
+
+	GIT_TRACE=1 GIT_TRACE_PACKET="$(pwd)/log" GIT_TEST_SIDEBAND_ALL=1 \
+	git -c protocol.version=2 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child &&
+
+	# Ensure that my-blob and other-blob are in separate packfiles.
+	for idx in http_child/.git/objects/pack/*.idx
+	do
+		git verify-pack --verbose $idx >out &&
+		{
+			grep "^[0-9a-f]\{16,\} " out || :
+		} >out.objectlist &&
+		if test_line_count = 1 out.objectlist
+		then
+			if grep $(cat h) out
+			then
+				>hfound
+			fi &&
+			if grep $(cat h2) out
+			then
+				>h2found
+			fi
+		fi
+	done &&
+	test -f hfound &&
+	test -f h2found &&
+
+	# Ensure that there are exactly 6 files (3 .pack and 3 .idx).
+	ls http_child/.git/objects/pack/* >filelist &&
+	test_line_count = 6 filelist
+'
+
+test_expect_success 'fetching with valid packfile URI but invalid hash fails' '
+	P="$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
+	rm -rf "$P" http_child log &&
+
+	git init "$P" &&
+	git -C "$P" config "uploadpack.allowsidebandall" "true" &&
+
+	echo my-blob >"$P/my-blob" &&
+	git -C "$P" add my-blob &&
+	echo other-blob >"$P/other-blob" &&
+	git -C "$P" add other-blob &&
+	git -C "$P" commit -m x &&
+
+	configure_exclusion "$P" my-blob >h &&
+	# Configure a URL for other-blob. Just reuse the hash of the object as
+	# the hash of the packfile, since the hash does not matter for this
+	# test as long as it is not the hash of the pack, and it is of the
+	# expected length.
+	git -C "$P" hash-object other-blob >objh &&
+	git -C "$P" pack-objects "$HTTPD_DOCUMENT_ROOT_PATH/mypack" <objh >packh &&
+	git -C "$P" config --add \
+		"uploadpack.blobpackfileuri" \
+		"$(cat objh) $(cat objh) $HTTPD_URL/dumb/mypack-$(cat packh).pack" &&
+
+	GIT_TEST_SIDEBAND_ALL=1 \
+	test_must_fail git -c protocol.version=2 \
+		-c fetch.uriprotocols=http,https \
+		clone "$HTTPD_URL/smart/http_parent" http_child 2>err &&
+	test_i18ngrep "pack downloaded from.*does not match expected hash" err
+'
+
 # DO NOT add non-httpd-specific tests here, because the last part of this
 # test script is only executed when httpd is available and enabled.
 
diff --git a/upload-pack.c b/upload-pack.c
index 13f6152560..d928d1c0a8 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -105,9 +105,12 @@  static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 struct output_state {
 	char buffer[8193];
 	int used;
+	unsigned packfile_uris_started : 1;
+	unsigned packfile_started : 1;
 };
 
-static int relay_pack_data(int pack_objects_out, struct output_state *os)
+static int relay_pack_data(int pack_objects_out, struct output_state *os,
+			   int write_packfile_line)
 {
 	/*
 	 * We keep the last byte to ourselves
@@ -128,6 +131,37 @@  static int relay_pack_data(int pack_objects_out, struct output_state *os)
 	}
 	os->used += readsz;
 
+	while (!os->packfile_started) {
+		char *p;
+		if (os->used >= 4 && !memcmp(os->buffer, "PACK", 4)) {
+			os->packfile_started = 1;
+			if (write_packfile_line) {
+				if (os->packfile_uris_started)
+					packet_delim(1);
+				packet_write_fmt(1, "\1packfile\n");
+			}
+			break;
+		}
+		if ((p = memchr(os->buffer, '\n', os->used))) {
+			if (!os->packfile_uris_started) {
+				os->packfile_uris_started = 1;
+				if (!write_packfile_line)
+					BUG("packfile_uris requires sideband-all");
+				packet_write_fmt(1, "\1packfile-uris\n");
+			}
+			*p = '\0';
+			packet_write_fmt(1, "\1%s\n", os->buffer);
+
+			os->used -= p - os->buffer + 1;
+			memmove(os->buffer, p + 1, os->used);
+		} else {
+			/*
+			 * Incomplete line.
+			 */
+			return readsz;
+		}
+	}
+
 	if (os->used > 1) {
 		send_client_data(1, os->buffer, os->used - 1);
 		os->buffer[0] = os->buffer[os->used - 1];
@@ -142,7 +176,8 @@  static int relay_pack_data(int pack_objects_out, struct output_state *os)
 
 static void create_pack_file(const struct object_array *have_obj,
 			     const struct object_array *want_obj,
-			     struct list_objects_filter_options *filter_options)
+			     struct list_objects_filter_options *filter_options,
+			     const struct string_list *uri_protocols)
 {
 	struct child_process pack_objects = CHILD_PROCESS_INIT;
 	struct output_state output_state = { { 0 } };
@@ -192,6 +227,11 @@  static void create_pack_file(const struct object_array *have_obj,
 					 spec);
 		}
 	}
+	if (uri_protocols) {
+		for (i = 0; i < uri_protocols->nr; i++)
+			argv_array_pushf(&pack_objects.args, "--uri-protocol=%s",
+					 uri_protocols->items[0].string);
+	}
 
 	pack_objects.in = -1;
 	pack_objects.out = -1;
@@ -278,7 +318,8 @@  static void create_pack_file(const struct object_array *have_obj,
 		}
 		if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 			int result = relay_pack_data(pack_objects.out,
-						     &output_state);
+						     &output_state,
+						     !!uri_protocols);
 
 			if (result == 0) {
 				close(pack_objects.out);
@@ -1137,7 +1178,7 @@  void upload_pack(struct upload_pack_options *options)
 	if (want_obj.nr) {
 		struct object_array have_obj = OBJECT_ARRAY_INIT;
 		get_common_commits(&reader, &have_obj, &want_obj);
-		create_pack_file(&have_obj, &want_obj, &filter_options);
+		create_pack_file(&have_obj, &want_obj, &filter_options, 0);
 	}
 
 	list_objects_filter_release(&filter_options);
@@ -1154,6 +1195,7 @@  struct upload_pack_data {
 	timestamp_t deepen_since;
 	int deepen_rev_list;
 	int deepen_relative;
+	struct string_list uri_protocols;
 
 	struct list_objects_filter_options filter_options;
 
@@ -1175,6 +1217,7 @@  static void upload_pack_data_init(struct upload_pack_data *data)
 	struct oid_array haves = OID_ARRAY_INIT;
 	struct object_array shallows = OBJECT_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
+	struct string_list uri_protocols = STRING_LIST_INIT_DUP;
 
 	memset(data, 0, sizeof(*data));
 	data->wants = wants;
@@ -1182,6 +1225,7 @@  static void upload_pack_data_init(struct upload_pack_data *data)
 	data->haves = haves;
 	data->shallows = shallows;
 	data->deepen_not = deepen_not;
+	data->uri_protocols = uri_protocols;
 	packet_writer_init(&data->writer, 1);
 }
 
@@ -1342,10 +1386,18 @@  static void process_args(struct packet_reader *request,
 			continue;
 		}
 
+		if (skip_prefix(arg, "packfile-uris ", &p)) {
+			string_list_split(&data->uri_protocols, p, ',', -1);
+			continue;
+		}
+
 		/* ignore unknown lines maybe? */
 		die("unexpected line: '%s'", arg);
 	}
 
+	if (data->uri_protocols.nr && !data->writer.use_sideband)
+		string_list_clear(&data->uri_protocols, 0);
+
 	if (request->status != PACKET_READ_FLUSH)
 		die(_("expected flush after fetch arguments"));
 }
@@ -1537,8 +1589,15 @@  int upload_pack_v2(struct repository *r, struct argv_array *keys,
 			send_wanted_ref_info(&data);
 			send_shallow_info(&data, &want_obj);
 
-			packet_writer_write(&data.writer, "packfile\n");
-			create_pack_file(&have_obj, &want_obj, &data.filter_options);
+			if (data.uri_protocols.nr) {
+				create_pack_file(&have_obj, &want_obj,
+						 &data.filter_options,
+						 &data.uri_protocols);
+			} else {
+				packet_writer_write(&data.writer, "packfile\n");
+				create_pack_file(&have_obj, &want_obj,
+						 &data.filter_options, NULL);
+			}
 			state = FETCH_DONE;
 			break;
 		case FETCH_DONE:
@@ -1559,6 +1618,7 @@  int upload_pack_advertise(struct repository *r,
 		int allow_filter_value;
 		int allow_ref_in_want;
 		int allow_sideband_all_value;
+		char *str = NULL;
 
 		strbuf_addstr(value, "shallow");
 
@@ -1580,6 +1640,14 @@  int upload_pack_advertise(struct repository *r,
 					   &allow_sideband_all_value) &&
 		     allow_sideband_all_value))
 			strbuf_addstr(value, " sideband-all");
+
+		if (!repo_config_get_string(the_repository,
+					    "uploadpack.blobpackfileuri",
+					    &str) &&
+		    str) {
+			strbuf_addstr(value, " packfile-uris");
+			free(str);
+		}
 	}
 
 	return 1;