On Thu Oct 23, 2025 at 10:57 PM -03, Quan Zongliang wrote: > On 10/23/25 9:56 PM, Euler Taveira wrote: > >> >> * insufficient privilege: if the role doesn't have the sufficient privileges, >> return NULL or '<insufficient privilege>' (similar to pg_stat_activity). I >> don't have a strong preference but the latter can impose more effort to >> use >> if you don't know the role has sufficient privilege. However, it is clear >> why >> the absolute path is not returned. >> > > +1 > I think this way is better. > So here it is, see attached.
I've created a new role pg_read_extension_paths for this, I'm not sure if it's the best way to do this. I'm open for other ideas, perhaps we can reuse some other role? -- Matheus Alcantara
From b398d76e53164263f93cbc6649ea7a79f6dc16b6 Mon Sep 17 00:00:00 2001 From: Matheus Alcantara <[email protected]> Date: Mon, 15 Sep 2025 15:46:24 -0300 Subject: [PATCH v3] Add path of extension on pg_available_extensions This adds a new "location" column on pg_available_extensions and pg_available_extension_versions views to show the path of locations that Postgres is seeing based on the extension_control_path GUC. The default system location is show as $system macro, the same value that is used to configure the extension_control_path GUC. User configured paths is only visible for users that has the pg_read_extension_paths role, otherwise <insufficient privilege> is returned as a column value, the same behaviour that we already have on pg_stat_activity. --- src/backend/catalog/system_views.sql | 4 +- src/backend/commands/extension.c | 103 ++++++++++++++---- src/include/catalog/pg_authid.dat | 5 + src/include/catalog/pg_proc.dat | 10 +- .../t/001_extension_control_path.pl | 48 +++++++- src/test/regress/expected/rules.out | 10 +- 6 files changed, 146 insertions(+), 34 deletions(-) diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 823776c1498..76eea11d48b 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -412,14 +412,14 @@ CREATE VIEW pg_cursors AS CREATE VIEW pg_available_extensions AS SELECT E.name, E.default_version, X.extversion AS installed_version, - E.comment + E.comment, E.location FROM pg_available_extensions() AS E LEFT JOIN pg_extension AS X ON E.name = X.extname; CREATE VIEW pg_available_extension_versions AS SELECT E.name, E.version, (X.extname IS NOT NULL) AS installed, E.superuser, E.trusted, E.relocatable, - E.schema, E.requires, E.comment + E.schema, E.requires, E.comment, E.location FROM pg_available_extension_versions() AS E LEFT JOIN pg_extension AS X ON E.name = X.extname AND E.version = X.extversion; diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c index 93ef1ad106f..c7f3568190c 100644 --- a/src/backend/commands/extension.c +++ b/src/backend/commands/extension.c @@ -126,6 +126,20 @@ typedef struct ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */ } script_error_callback_arg; +/* + * A location configured on extension_control_path GUC. + * + * The macro field stores the name of a macro (for example “$system”) that + * extension_control_path supports, which is replaced by a system value that is + * stored in loc. For custom paths that don't have a macro the macro field is + * NULL. + */ +typedef struct +{ + char *macro; + char *loc; +} Location; + /* Local functions */ static List *find_update_path(List *evi_list, ExtensionVersionInfo *evi_start, @@ -140,7 +154,8 @@ static Oid get_required_extension(char *reqExtensionName, bool is_create); static void get_available_versions_for_extension(ExtensionControlFile *pcontrol, Tuplestorestate *tupstore, - TupleDesc tupdesc); + TupleDesc tupdesc, + Location *location); static Datum convert_requires_to_datum(List *requires); static void ApplyExtensionUpdates(Oid extensionOid, ExtensionControlFile *pcontrol, @@ -157,6 +172,34 @@ static ExtensionControlFile *new_ExtensionControlFile(const char *extname); char *find_in_paths(const char *basename, List *paths); +/* + * Return the location to display for the given Location based on the user + * privileges. If the user connected to the database don't have the + * permissions <insufficient privilege> is returned. + */ +static char * +location_to_display(Location *loc) +{ + Oid userid = GetUserId(); + bool is_allowed_role; + + is_allowed_role = has_privs_of_role(userid, ROLE_PG_READ_EXTENSION_PATHS); + + if (is_allowed_role) + { + /* + * Return the macro value if it's present to don't show system paths. + * We only want to show user custom paths if it has the privilege. + */ + if (loc->macro == NULL) + return loc->loc; + else + return loc->macro; + } + else + return "<insufficient privilege>"; +} + /* * get_extension_oid - given an extension name, look up the OID * @@ -354,7 +397,11 @@ get_extension_control_directories(void) if (strlen(Extension_control_path) == 0) { - paths = lappend(paths, system_dir); + Location *location = palloc_object(Location); + + location->macro = NULL; + location->loc = system_dir; + paths = lappend(paths, location); } else { @@ -366,6 +413,7 @@ get_extension_control_directories(void) int len; char *mangled; char *piece = first_path_var_separator(ecp); + Location *location = palloc_object(Location); /* Get the length of the next path on ecp */ if (piece == NULL) @@ -382,15 +430,21 @@ get_extension_control_directories(void) * suffix if it is a custom extension control path. */ if (strcmp(piece, "$system") == 0) + { + location->macro = pstrdup(piece); mangled = substitute_path_macro(piece, "$system", system_dir); + } else + { + location->macro = NULL; mangled = psprintf("%s/extension", piece); - + } pfree(piece); /* Canonicalize the path based on the OS and add to the list */ canonicalize_path(mangled); - paths = lappend(paths, mangled); + location->loc = mangled; + paths = lappend(paths, location); /* Break if ecp is empty or move to the next path on ecp */ if (ecp[len] == '\0') @@ -2215,9 +2269,9 @@ pg_available_extensions(PG_FUNCTION_ARGS) locations = get_extension_control_directories(); - foreach_ptr(char, location, locations) + foreach_ptr(Location, location, locations) { - dir = AllocateDir(location); + dir = AllocateDir(location->loc); /* * If the control directory doesn't exist, we want to silently return @@ -2229,13 +2283,13 @@ pg_available_extensions(PG_FUNCTION_ARGS) } else { - while ((de = ReadDir(dir, location)) != NULL) + while ((de = ReadDir(dir, location->loc)) != NULL) { ExtensionControlFile *control; char *extname; String *extname_str; - Datum values[3]; - bool nulls[3]; + Datum values[4]; + bool nulls[4]; if (!is_extension_control_filename(de->d_name)) continue; @@ -2259,7 +2313,7 @@ pg_available_extensions(PG_FUNCTION_ARGS) found_ext = lappend(found_ext, extname_str); control = new_ExtensionControlFile(extname); - control->control_dir = pstrdup(location); + control->control_dir = pstrdup(location->loc); parse_extension_control_file(control, NULL); memset(values, 0, sizeof(values)); @@ -2279,6 +2333,9 @@ pg_available_extensions(PG_FUNCTION_ARGS) else values[2] = CStringGetTextDatum(control->comment); + /* location */ + values[3] = CStringGetTextDatum(location_to_display(location)); + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); } @@ -2313,9 +2370,9 @@ pg_available_extension_versions(PG_FUNCTION_ARGS) locations = get_extension_control_directories(); - foreach_ptr(char, location, locations) + foreach_ptr(Location, location, locations) { - dir = AllocateDir(location); + dir = AllocateDir(location->loc); /* * If the control directory doesn't exist, we want to silently return @@ -2327,7 +2384,7 @@ pg_available_extension_versions(PG_FUNCTION_ARGS) } else { - while ((de = ReadDir(dir, location)) != NULL) + while ((de = ReadDir(dir, location->loc)) != NULL) { ExtensionControlFile *control; char *extname; @@ -2356,12 +2413,13 @@ pg_available_extension_versions(PG_FUNCTION_ARGS) /* read the control file */ control = new_ExtensionControlFile(extname); - control->control_dir = pstrdup(location); + control->control_dir = pstrdup(location->loc); parse_extension_control_file(control, NULL); /* scan extension's script directory for install scripts */ get_available_versions_for_extension(control, rsinfo->setResult, - rsinfo->setDesc); + rsinfo->setDesc, + location); } FreeDir(dir); @@ -2378,7 +2436,8 @@ pg_available_extension_versions(PG_FUNCTION_ARGS) static void get_available_versions_for_extension(ExtensionControlFile *pcontrol, Tuplestorestate *tupstore, - TupleDesc tupdesc) + TupleDesc tupdesc, + Location *location) { List *evi_list; ListCell *lc; @@ -2391,8 +2450,8 @@ get_available_versions_for_extension(ExtensionControlFile *pcontrol, { ExtensionVersionInfo *evi = (ExtensionVersionInfo *) lfirst(lc); ExtensionControlFile *control; - Datum values[8]; - bool nulls[8]; + Datum values[9]; + bool nulls[9]; ListCell *lc2; if (!evi->installable) @@ -2434,6 +2493,9 @@ get_available_versions_for_extension(ExtensionControlFile *pcontrol, else values[7] = CStringGetTextDatum(control->comment); + /* location */ + values[8] = CStringGetTextDatum(location_to_display(location)); + tuplestore_putvalues(tupstore, tupdesc, values, nulls); /* @@ -2475,6 +2537,8 @@ get_available_versions_for_extension(ExtensionControlFile *pcontrol, } /* comment stays the same */ + /* location stays the same */ + tuplestore_putvalues(tupstore, tupdesc, values, nulls); } } @@ -3903,7 +3967,8 @@ find_in_paths(const char *basename, List *paths) foreach(cell, paths) { - char *path = lfirst(cell); + Location *location = lfirst(cell); + char *path = location->loc; char *full; Assert(path != NULL); diff --git a/src/include/catalog/pg_authid.dat b/src/include/catalog/pg_authid.dat index c881c13adf1..af18eb8c1c9 100644 --- a/src/include/catalog/pg_authid.dat +++ b/src/include/catalog/pg_authid.dat @@ -104,5 +104,10 @@ rolcreaterole => 'f', rolcreatedb => 'f', rolcanlogin => 'f', rolreplication => 'f', rolbypassrls => 'f', rolconnlimit => '-1', rolpassword => '_null_', rolvaliduntil => '_null_' }, +{ oid => '6434', oid_symbol => 'ROLE_PG_READ_EXTENSION_PATHS', + rolname => 'pg_read_extension_paths', rolsuper => 'f', rolinherit => 't', + rolcreaterole => 'f', rolcreatedb => 'f', rolcanlogin => 'f', + rolreplication => 'f', rolbypassrls => 'f', rolconnlimit => '-1', + rolpassword => '_null_', rolvaliduntil => '_null_' }, ] diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index eecb43ec6f0..ab5ec86ca9d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -10743,16 +10743,16 @@ { oid => '3082', descr => 'list available extensions', proname => 'pg_available_extensions', procost => '10', prorows => '100', proretset => 't', provolatile => 's', prorettype => 'record', - proargtypes => '', proallargtypes => '{name,text,text}', - proargmodes => '{o,o,o}', proargnames => '{name,default_version,comment}', + proargtypes => '', proallargtypes => '{name,text,text,text}', + proargmodes => '{o,o,o,o}', proargnames => '{name,default_version,comment,location}', prosrc => 'pg_available_extensions' }, { oid => '3083', descr => 'list available extension versions', proname => 'pg_available_extension_versions', procost => '10', prorows => '100', proretset => 't', provolatile => 's', prorettype => 'record', proargtypes => '', - proallargtypes => '{name,text,bool,bool,bool,name,_name,text}', - proargmodes => '{o,o,o,o,o,o,o,o}', - proargnames => '{name,version,superuser,trusted,relocatable,schema,requires,comment}', + proallargtypes => '{name,text,bool,bool,bool,name,_name,text,text}', + proargmodes => '{o,o,o,o,o,o,o,o,o}', + proargnames => '{name,version,superuser,trusted,relocatable,schema,requires,comment,location}', prosrc => 'pg_available_extension_versions' }, { oid => '3084', descr => 'list an extension\'s version update paths', proname => 'pg_extension_update_paths', procost => '10', prorows => '100', diff --git a/src/test/modules/test_extensions/t/001_extension_control_path.pl b/src/test/modules/test_extensions/t/001_extension_control_path.pl index 7fbe5bde332..1c70a27cffa 100644 --- a/src/test/modules/test_extensions/t/001_extension_control_path.pl +++ b/src/test/modules/test_extensions/t/001_extension_control_path.pl @@ -25,6 +25,10 @@ my $ext_name2 = "test_custom_ext_paths_using_directory"; mkpath("$ext_dir/$ext_name2"); create_extension($ext_name2, $ext_dir, $ext_name2); +# Make windows path use Unix slashes as canonicalize_path() is called when +# collecting extension control paths. See get_extension_control_directories(). +my $ext_dir_canonicalized = $windows_os ? ($ext_dir =~ s/\\/\//gr) : $ext_dir; + # Use the correct separator and escape \ when running on Windows. my $sep = $windows_os ? ";" : ":"; $node->append_conf( @@ -35,6 +39,10 @@ extension_control_path = '\$system$sep@{[ $windows_os ? ($ext_dir =~ s/\\/\\\\/g # Start node $node->start; +# Create an user to test permissions to read extension locations. +my $user = "user01"; +$node->safe_psql('postgres', "CREATE USER $user"); + my $ecp = $node->safe_psql('postgres', 'show extension_control_path;'); is($ecp, "\$system$sep$ext_dir$sep$ext_dir2", @@ -43,31 +51,63 @@ is($ecp, "\$system$sep$ext_dir$sep$ext_dir2", $node->safe_psql('postgres', "CREATE EXTENSION $ext_name"); $node->safe_psql('postgres', "CREATE EXTENSION $ext_name2"); + my $ret = $node->safe_psql('postgres', "select * from pg_available_extensions where name = '$ext_name'"); is( $ret, - "test_custom_ext_paths|1.0|1.0|Test extension_control_path", + "test_custom_ext_paths|1.0|1.0|Test extension_control_path|$ext_dir_canonicalized/extension", "extension is installed correctly on pg_available_extensions"); $ret = $node->safe_psql('postgres', "select * from pg_available_extension_versions where name = '$ext_name'"); is( $ret, - "test_custom_ext_paths|1.0|t|t|f|t|||Test extension_control_path", + "test_custom_ext_paths|1.0|t|t|f|t|||Test extension_control_path|$ext_dir_canonicalized/extension", "extension is installed correctly on pg_available_extension_versions"); $ret = $node->safe_psql('postgres', "select * from pg_available_extensions where name = '$ext_name2'"); is( $ret, - "test_custom_ext_paths_using_directory|1.0|1.0|Test extension_control_path", + "test_custom_ext_paths_using_directory|1.0|1.0|Test extension_control_path|$ext_dir_canonicalized/extension", "extension is installed correctly on pg_available_extensions"); $ret = $node->safe_psql('postgres', "select * from pg_available_extension_versions where name = '$ext_name2'" ); is( $ret, - "test_custom_ext_paths_using_directory|1.0|t|t|f|t|||Test extension_control_path", + "test_custom_ext_paths_using_directory|1.0|t|t|f|t|||Test extension_control_path|$ext_dir_canonicalized/extension", "extension is installed correctly on pg_available_extension_versions"); +# Test insufficient roles to read extension locations +$ret = $node->safe_psql('postgres', + "select location from pg_available_extensions where name = '$ext_name2'", + connstr => "user=$user"); +is( $ret, + "<insufficient privilege>", + "extension location is hide on pg_available_extensions for insufficient privilege"); + +$ret = $node->safe_psql('postgres', + "select location from pg_available_extension_versions where name = '$ext_name2'", + connstr => "user=$user"); +is( $ret, + "<insufficient privilege>", + "extension location is hide on pg_available_extension_versions for insufficient privilege"); + +# Now give the access and test it again +$node->safe_psql('postgres', "GRANT pg_read_extension_paths TO $user"); + +$ret = $node->safe_psql('postgres', + "select location from pg_available_extensions where name = '$ext_name2'"); +is( $ret, + "$ext_dir_canonicalized/extension", + "extension location is not hide on pg_available_extensions with sufficient privilege"); + +$ret = $node->safe_psql('postgres', + "select location from pg_available_extension_versions where name = '$ext_name2'" +); +is( $ret, + "$ext_dir_canonicalized/extension", + "extension location is not hide on pg_available_extension_versions with sufficient privilege"); + # Ensure that extensions installed on $system is still visible when using with # custom extension control path. $ret = $node->safe_psql('postgres', diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 16753b2e4c0..85da655b893 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1310,14 +1310,16 @@ pg_available_extension_versions| SELECT e.name, e.relocatable, e.schema, e.requires, - e.comment - FROM (pg_available_extension_versions() e(name, version, superuser, trusted, relocatable, schema, requires, comment) + e.comment, + e.location + FROM (pg_available_extension_versions() e(name, version, superuser, trusted, relocatable, schema, requires, comment, location) LEFT JOIN pg_extension x ON (((e.name = x.extname) AND (e.version = x.extversion)))); pg_available_extensions| SELECT e.name, e.default_version, x.extversion AS installed_version, - e.comment - FROM (pg_available_extensions() e(name, default_version, comment) + e.comment, + e.location + FROM (pg_available_extensions() e(name, default_version, comment, location) LEFT JOIN pg_extension x ON ((e.name = x.extname))); pg_backend_memory_contexts| SELECT name, ident, -- 2.51.0
