From: Glen Choo <chooglen@xxxxxxxxxx>
`uploadpack.packObjectsHook` is the only 'protected configuration only'
variable today, but we've noted that `safe.directory` and the upcoming
`discovery.bare` should also be 'protected configuration only'. So, for
consistency, we'd like to have a single implementation for protected
config.
The primary constraints are:
1. Reading from protected configuration should be as fast as possible.
Nearly all "git" commands inside a bare repository will read both
`safe.directory` and `discovery.bare`, so we cannot afford to be
slow.
2. Protected config must be readable when the gitdir is not known.
`safe.directory` and `discovery.bare` both affect repository
discovery and the gitdir is not known at that point [1].
The chosen implementation in this commit is to read protected
configuration and cache the values in a global configset. This is
similar to the caching behavior we get with the_repository->config.
Introduce git_protected_config(), which reads protected configuration
and caches them in the global configset protected_config. Then, refactor
`uploadpack.packObjectsHook` to use git_protected_config().
The protected configuration functions are named similarly to their
non-protected counterparts, e.g. git_protected_config_check_init() vs
git_config_check_init().
In light of constraint 1, this implementation can still be improved
since git_protected_config() iterates through every variable in
protected_config, which may still be too expensive. There exist constant
time lookup functions for non-protected configuration
(repo_config_get_*()), but for simplicity, this commit does not
implement similar functions for protected configuration.
An alternative that avoids introducing another configset is to continue
to read all config using git_config(), but only accept values that have
the correct config scope [2]. This technically fulfills constraint 2,
because git_config() simply ignores the local and worktree config when
the gitdir is not known. However, this would read incomplete config into
the_repository->config, which would need to be reset when the gitdir is
known and git_config() needs to read the local and worktree config.
Resetting the_repository->config might be reasonable while we only have
these 'protected configuration only' variables, but it's not clear
whether this extends well to future variables.
[1] In this case, we do have a candidate gitdir though, so with a little
refactoring, it might be possible to provide a gitdir.
[2] This is how `uploadpack.packObjectsHook` was implemented prior to
this commit.
Signed-off-by: Glen Choo <chooglen@xxxxxxxxxx>
---
config.c | 51 ++++++++++++++++++++++++++++++++++++
config.h | 17 ++++++++++++
t/t5544-pack-objects-hook.sh | 7 ++++-
upload-pack.c | 27 ++++++++++++-------
4 files changed, 91 insertions(+), 11 deletions(-)
diff --git a/config.c b/config.c
index 9b0e9c93285..29e62f5d0ed 100644
--- a/config.c
+++ b/config.c
@@ -81,6 +81,18 @@ static enum config_scope current_parsing_scope;
static int pack_compression_seen;
static int zlib_compression_seen;
+/*
+ * Config that comes from trusted sources, namely:
+ * - system config files (e.g. /etc/gitconfig)
+ * - global config files (e.g. $HOME/.gitconfig,
+ * $XDG_CONFIG_HOME/git)
+ * - the command line.
+ *
+ * This is declared here for code cleanliness, but unlike the other
+ * static variables, this does not hold config parser state.
+ */
+static struct config_set protected_config;
+
static int config_file_fgetc(struct config_source *conf)
{
return getc_unlocked(conf->u.file);
@@ -2378,6 +2390,11 @@ int git_configset_add_file(struct config_set *cs, const char *filename)
return git_config_from_file(config_set_callback, filename, cs);
}
+int git_configset_add_parameters(struct config_set *cs)
+{
+ return git_config_from_parameters(config_set_callback, cs);
+}
+
int git_configset_get_value(struct config_set *cs, const char *key, const char **value)
{
const struct string_list *values = NULL;
@@ -2619,6 +2636,40 @@ int repo_config_get_pathname(struct repository *repo,
return ret;
}
+/* Read values into protected_config. */
+static void read_protected_config(void)
+{
+ char *xdg_config = NULL, *user_config = NULL, *system_config = NULL;
+
+ git_configset_init(&protected_config);
+
+ system_config = git_system_config();
+ git_global_config(&user_config, &xdg_config);
+
+ git_configset_add_file(&protected_config, system_config);
+ git_configset_add_file(&protected_config, xdg_config);
+ git_configset_add_file(&protected_config, user_config);
+ git_configset_add_parameters(&protected_config);
+
+ free(system_config);
+ free(xdg_config);
+ free(user_config);
+}
+
+/* Ensure that protected_config has been initialized. */
+static void git_protected_config_check_init(void)
+{
+ if (protected_config.hash_initialized)
+ return;
+ read_protected_config();
+}
+
+void git_protected_config(config_fn_t fn, void *data)
+{
+ git_protected_config_check_init();
+ configset_iter(&protected_config, fn, data);
+}
+
/* Functions used historically to read configuration from 'the_repository' */
void git_config(config_fn_t fn, void *data)
{
diff --git a/config.h b/config.h
index 7654f61c634..e3ff1fcf683 100644
--- a/config.h
+++ b/config.h
@@ -446,6 +446,15 @@ void git_configset_init(struct config_set *cs);
*/
int git_configset_add_file(struct config_set *cs, const char *filename);
+/**
+ * Parses command line options and environment variables, and adds the
+ * variable-value pairs to the `config_set`. Returns 0 on success, or -1
+ * if there is an error in parsing. The caller decides whether to free
+ * the incomplete configset or continue using it when the function
+ * returns -1.
+ */
+int git_configset_add_parameters(struct config_set *cs);
+
/**
* Finds and returns the value list, sorted in order of increasing priority
* for the configuration variable `key` and config set `cs`. When the
@@ -505,6 +514,14 @@ int repo_config_get_maybe_bool(struct repository *repo,
int repo_config_get_pathname(struct repository *repo,
const char *key, const char **dest);
+/*
+ * Functions for reading protected config. By definition, protected
+ * config ignores repository config, so it is unnecessary to read
+ * protected config from any `struct repository` other than
+ * the_repository.
+ */
+void git_protected_config(config_fn_t fn, void *data);
+
/**
* Querying For Specific Variables
* -------------------------------
diff --git a/t/t5544-pack-objects-hook.sh b/t/t5544-pack-objects-hook.sh
index dd5f44d986f..54f54f8d2eb 100755
--- a/t/t5544-pack-objects-hook.sh
+++ b/t/t5544-pack-objects-hook.sh
@@ -56,7 +56,12 @@ test_expect_success 'hook does not run from repo config' '
! grep "hook running" stderr &&
test_path_is_missing .git/hook.args &&
test_path_is_missing .git/hook.stdin &&
- test_path_is_missing .git/hook.stdout
+ test_path_is_missing .git/hook.stdout &&
+
+ # check that global config is used instead
+ test_config_global uploadpack.packObjectsHook ./hook &&
+ git clone --no-local . dst2.git 2>stderr &&
+ grep "hook running" stderr
'
test_expect_success 'hook works with partial clone' '
diff --git a/upload-pack.c b/upload-pack.c
index 3a851b36066..09f48317b02 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1321,18 +1321,27 @@ static int upload_pack_config(const char *var, const char *value, void *cb_data)
data->advertise_sid = git_config_bool(var, value);
}
- if (current_config_scope() != CONFIG_SCOPE_LOCAL &&
- current_config_scope() != CONFIG_SCOPE_WORKTREE) {
- if (!strcmp("uploadpack.packobjectshook", var))
- return git_config_string(&data->pack_objects_hook, var, value);
- }
-
if (parse_object_filter_config(var, value, data) < 0)
return -1;
return parse_hide_refs_config(var, value, "uploadpack");
}
+static int upload_pack_protected_config(const char *var, const char *value, void *cb_data)
+{
+ struct upload_pack_data *data = cb_data;
+
+ if (!strcmp("uploadpack.packobjectshook", var))
+ return git_config_string(&data->pack_objects_hook, var, value);
+ return 0;
+}
+
+static void get_upload_pack_config(struct upload_pack_data *data)
+{
+ git_config(upload_pack_config, data);
+ git_protected_config(upload_pack_protected_config, data);
+}
+
void upload_pack(const int advertise_refs, const int stateless_rpc,
const int timeout)
{
@@ -1340,8 +1349,7 @@ void upload_pack(const int advertise_refs, const int stateless_rpc,
struct upload_pack_data data;
upload_pack_data_init(&data);
-
- git_config(upload_pack_config, &data);
+ get_upload_pack_config(&data);
data.stateless_rpc = stateless_rpc;
data.timeout = timeout;
@@ -1695,8 +1703,7 @@ int upload_pack_v2(struct repository *r, struct packet_reader *request)
upload_pack_data_init(&data);
data.use_sideband = LARGE_PACKET_MAX;
-
- git_config(upload_pack_config, &data);
+ get_upload_pack_config(&data);
while (state != FETCH_DONE) {
switch (state) {
--
gitgitgadget
