promisor-remote: check advertised name or URL

A previous commit introduced a "promisor.acceptFromServer" configuration
variable with only "None" or "All" as valid values.

Let's introduce "KnownName" and "KnownUrl" as valid values for this
configuration option to give more choice to a client about which
promisor remotes it might accept among those that the server advertised.

In case of "KnownName", the client will accept promisor remotes which
are already configured on the client and have the same name as those
advertised by the client. This could be useful in a corporate setup
where servers and clients are trusted to not switch names and URLs, but
where some kind of control is still useful.

In case of "KnownUrl", the client will accept promisor remotes which
have both the same name and the same URL configured on the client as the
name and URL advertised by the server. This is the most secure option,
so it should be used if possible.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
main
Christian Couder 2025-02-18 12:32:03 +01:00 committed by Junio C Hamano
parent d460267613
commit 36463e32df
3 changed files with 138 additions and 12 deletions

View File

@ -12,9 +12,19 @@ promisor.advertise::
promisor.acceptFromServer::
If set to "all", a client will accept all the promisor remotes
a server might advertise using the "promisor-remote"
capability. Default is "none", which means no promisor remote
advertised by a server will be accepted. By accepting a
promisor remote, the client agrees that the server might omit
objects that are lazily fetchable from this promisor remote
from its responses to "fetch" and "clone" requests from the
client. See linkgit:gitprotocol-v2[5].
capability. If set to "knownName" the client will accept
promisor remotes which are already configured on the client
and have the same name as those advertised by the client. This
is not very secure, but could be used in a corporate setup
where servers and clients are trusted to not switch name and
URLs. If set to "knownUrl", the client will accept promisor
remotes which have both the same name and the same URL
configured on the client as the name and URL advertised by the
server. This is more secure than "all" or "knownName", so it
should be used if possible instead of those options. Default
is "none", which means no promisor remote advertised by a
server will be accepted. By accepting a promisor remote, the
client agrees that the server might omit objects that are
lazily fetchable from this promisor remote from its responses
to "fetch" and "clone" requests from the client. See
linkgit:gitprotocol-v2[5].

View File

@ -368,30 +368,73 @@ char *promisor_remote_info(struct repository *repo)
return strbuf_detach(&sb, NULL);
}

/*
* Find first index of 'nicks' where there is 'nick'. 'nick' is
* compared case insensitively to the strings in 'nicks'. If not found
* 'nicks->nr' is returned.
*/
static size_t remote_nick_find(struct strvec *nicks, const char *nick)
{
for (size_t i = 0; i < nicks->nr; i++)
if (!strcasecmp(nicks->v[i], nick))
return i;
return nicks->nr;
}

enum accept_promisor {
ACCEPT_NONE = 0,
ACCEPT_KNOWN_URL,
ACCEPT_KNOWN_NAME,
ACCEPT_ALL
};

static int should_accept_remote(enum accept_promisor accept,
const char *remote_name UNUSED,
const char *remote_url UNUSED)
const char *remote_name, const char *remote_url,
struct strvec *names, struct strvec *urls)
{
size_t i;

if (accept == ACCEPT_ALL)
return 1;

BUG("Unhandled 'enum accept_promisor' value '%d'", accept);
i = remote_nick_find(names, remote_name);

if (i >= names->nr)
/* We don't know about that remote */
return 0;

if (accept == ACCEPT_KNOWN_NAME)
return 1;

if (accept != ACCEPT_KNOWN_URL)
BUG("Unhandled 'enum accept_promisor' value '%d'", accept);

if (!strcmp(urls->v[i], remote_url))
return 1;

warning(_("known remote named '%s' but with url '%s' instead of '%s'"),
remote_name, urls->v[i], remote_url);

return 0;
}

static void filter_promisor_remote(struct strvec *accepted, const char *info)
static void filter_promisor_remote(struct repository *repo,
struct strvec *accepted,
const char *info)
{
struct strbuf **remotes;
const char *accept_str;
enum accept_promisor accept = ACCEPT_NONE;
struct strvec names = STRVEC_INIT;
struct strvec urls = STRVEC_INIT;

if (!git_config_get_string_tmp("promisor.acceptfromserver", &accept_str)) {
if (!*accept_str || !strcasecmp("None", accept_str))
accept = ACCEPT_NONE;
else if (!strcasecmp("KnownUrl", accept_str))
accept = ACCEPT_KNOWN_URL;
else if (!strcasecmp("KnownName", accept_str))
accept = ACCEPT_KNOWN_NAME;
else if (!strcasecmp("All", accept_str))
accept = ACCEPT_ALL;
else
@ -402,6 +445,9 @@ static void filter_promisor_remote(struct strvec *accepted, const char *info)
if (accept == ACCEPT_NONE)
return;

if (accept != ACCEPT_ALL)
promisor_info_vecs(repo, &names, &urls);

/* Parse remote info received */

remotes = strbuf_split_str(info, ';', 0);
@ -431,7 +477,7 @@ static void filter_promisor_remote(struct strvec *accepted, const char *info)
if (remote_url)
decoded_url = url_percent_decode(remote_url);

if (decoded_name && should_accept_remote(accept, decoded_name, decoded_url))
if (decoded_name && should_accept_remote(accept, decoded_name, decoded_url, &names, &urls))
strvec_push(accepted, decoded_name);

strbuf_list_free(elems);
@ -439,6 +485,8 @@ static void filter_promisor_remote(struct strvec *accepted, const char *info)
free(decoded_url);
}

strvec_clear(&names);
strvec_clear(&urls);
strbuf_list_free(remotes);
}

@ -447,7 +495,7 @@ char *promisor_remote_reply(const char *info)
struct strvec accepted = STRVEC_INIT;
struct strbuf reply = STRBUF_INIT;

filter_promisor_remote(&accepted, info);
filter_promisor_remote(the_repository, &accepted, info);

if (!accepted.nr)
return NULL;

View File

@ -160,6 +160,74 @@ test_expect_success "init + fetch with promisor.advertise set to 'true'" '
check_missing_objects server 1 "$oid"
'

test_expect_success "clone with promisor.acceptfromserver set to 'KnownName'" '
git -C server config promisor.advertise true &&

# Clone from server to create a client
GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-c remote.lop.url="file://$(pwd)/lop" \
-c promisor.acceptfromserver=KnownName \
--no-local --filter="blob:limit=5k" server client &&
test_when_finished "rm -rf client" &&

# Check that the largest object is still missing on the server
check_missing_objects server 1 "$oid"
'

test_expect_success "clone with 'KnownName' and different remote names" '
git -C server config promisor.advertise true &&

# Clone from server to create a client
GIT_NO_LAZY_FETCH=0 git clone -c remote.serverTwo.promisor=true \
-c remote.serverTwo.fetch="+refs/heads/*:refs/remotes/lop/*" \
-c remote.serverTwo.url="file://$(pwd)/lop" \
-c promisor.acceptfromserver=KnownName \
--no-local --filter="blob:limit=5k" server client &&
test_when_finished "rm -rf client" &&

# Check that the largest object is not missing on the server
check_missing_objects server 0 "" &&

# Reinitialize server so that the largest object is missing again
initialize_server 1 "$oid"
'

test_expect_success "clone with promisor.acceptfromserver set to 'KnownUrl'" '
git -C server config promisor.advertise true &&

# Clone from server to create a client
GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-c remote.lop.url="file://$(pwd)/lop" \
-c promisor.acceptfromserver=KnownUrl \
--no-local --filter="blob:limit=5k" server client &&
test_when_finished "rm -rf client" &&

# Check that the largest object is still missing on the server
check_missing_objects server 1 "$oid"
'

test_expect_success "clone with 'KnownUrl' and different remote urls" '
ln -s lop serverTwo &&

git -C server config promisor.advertise true &&

# Clone from server to create a client
GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-c remote.lop.url="file://$(pwd)/serverTwo" \
-c promisor.acceptfromserver=KnownUrl \
--no-local --filter="blob:limit=5k" server client &&
test_when_finished "rm -rf client" &&

# Check that the largest object is not missing on the server
check_missing_objects server 0 "" &&

# Reinitialize server so that the largest object is missing again
initialize_server 1 "$oid"
'

test_expect_success "clone with promisor.advertise set to 'true' but don't delete the client" '
git -C server config promisor.advertise true &&