From 0ec0deaa30d0e68430f03fa6f32affa576481d18 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 8 Oct 2015 22:31:56 +0200 Subject: install: follow unit file symlinks in /usr, but not /etc when looking for [Install] data Some distributions use alias unit files via symlinks in /usr to cover for legacy service names. With this change we'll allow "systemctl enable" on such aliases. Previously, our rule was that symlinks are user configuration that "systemctl enable" + "systemctl disable" creates and removes, while unit files is where the instructions to do so are store. As a result of the rule we'd never read install information through symlinks, since that would mix enablement state with installation instructions. Now, the new rule is that only symlinks inside of /etc are configuration. Unit files, and symlinks in /usr are now valid for installation instructions. This patch is quite a rework of the whole install logic, and makes the following addional changes: - Adds a complete test "test-instal-root" that tests the install logic pretty comprehensively. - Never uses canonicalize_file_name(), because that's incompatible with operation relative to a specific root directory. - unit_file_get_state() is reworked to return a proper error, and returns the state in a call-by-ref parameter. This cleans up confusion between the enum type and errno-like errors. - The new logic puts a limit on how long to follow unit file symlinks: it will do so only for 64 steps at max. - The InstallContext object's fields are renamed to will_process and has_processed (will_install and has_installed) since they are also used for deinstallation and all kinds of other operations. - The root directory is always verified before use. - install.c is reordered to place the exported functions together. - Stricter rules are followed when traversing symlinks: the unit suffix must say identical, and it's not allowed to link between regular units and templated units. - Various modernizations - The "invalid" unit file state has been renamed to "bad", in order to avoid confusion between UNIT_FILE_INVALID and _UNIT_FILE_STATE_INVALID. Given that the state should normally not be seen and is not documented this should not be a problematic change. The new name is now documented however. Fixes #1375, #1718, #1706 --- src/core/unit.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'src/core/unit.c') diff --git a/src/core/unit.c b/src/core/unit.c index ccdc5191e8..a67b9f282f 100644 --- a/src/core/unit.c +++ b/src/core/unit.c @@ -3148,12 +3148,19 @@ int unit_following_set(Unit *u, Set **s) { } UnitFileState unit_get_unit_file_state(Unit *u) { + int r; + assert(u); - if (u->unit_file_state < 0 && u->fragment_path) - u->unit_file_state = unit_file_get_state( + if (u->unit_file_state < 0 && u->fragment_path) { + r = unit_file_get_state( u->manager->running_as == MANAGER_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER, - NULL, basename(u->fragment_path)); + NULL, + basename(u->fragment_path), + &u->unit_file_state); + if (r < 0) + u->unit_file_state = UNIT_FILE_BAD; + } return u->unit_file_state; } @@ -3164,7 +3171,8 @@ int unit_get_unit_file_preset(Unit *u) { if (u->unit_file_preset < 0 && u->fragment_path) u->unit_file_preset = unit_file_query_preset( u->manager->running_as == MANAGER_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER, - NULL, basename(u->fragment_path)); + NULL, + basename(u->fragment_path)); return u->unit_file_preset; } -- cgit v1.2.3-54-g00ecf