From 635fe81b0ad6d217e2b16e1c05adef8934ecd3de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Thu, 24 Apr 2014 01:44:10 -0400
Subject: [PATCH] Make systemctl --root look for files in the proper places
Running systemctl enable/disable/set-default/... with the --root
option under strace reveals that it accessed various files and
directories in the main fs, and not underneath the specified root.
This can lead to correct results only when the layout and
configuration in the container are identical, which often is not the
case. Fix this by adding the specified root to all file access
operations.
This patch does not handle some corner cases: symlinks which point
outside of the specified root might be interpreted differently than
they would be by the kernel if the specified root was the real root.
But systemctl does not create such symlinks by itself, and I think
this is enough of a corner case not to be worth the additional
complexity of reimplementing link chasing in systemd.
Also, simplify the code in a few places and remove an hypothetical
memory leak on error.
(cherry picked from commit 12ed81d9c88406234c20e9261ae8c8b992d8bc4d)
Conflicts:
TODO
(cherry picked from commit fd516dfa0612d2a169158bbed6f8994f47f3e6ce)
Conflicts:
src/shared/install.c
---
src/core/manager.c | 2 ++
src/shared/install.c | 34 +++++++++++++++++++++-----------
src/shared/path-lookup.c | 12 ++++--------
src/shared/path-lookup.h | 8 +++++++-
src/shared/path-util.c | 49 ++++++++++++++++++++++++++++++++++++-----------
src/systemctl/systemctl.c | 2 +-
6 files changed, 75 insertions(+), 32 deletions(-)
diff --git a/src/core/manager.c b/src/core/manager.c
index 28f4d72e26..1baa8631a1 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -890,6 +890,7 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
r = lookup_paths_init(
&m->lookup_paths, m->running_as, true,
+ NULL,
m->generator_unit_path,
m->generator_unit_path_early,
m->generator_unit_path_late);
@@ -2390,6 +2391,7 @@ int manager_reload(Manager *m) {
q = lookup_paths_init(
&m->lookup_paths, m->running_as, true,
+ NULL,
m->generator_unit_path,
m->generator_unit_path_early,
m->generator_unit_path_late);
diff --git a/src/shared/install.c b/src/shared/install.c
index 9f34ac5ad5..cb07947527 100644
--- a/src/shared/install.c
+++ b/src/shared/install.c
@@ -47,7 +47,9 @@ typedef struct {
#define _cleanup_lookup_paths_free_ _cleanup_(lookup_paths_free)
#define _cleanup_install_context_done_ _cleanup_(install_context_done)
-static int lookup_paths_init_from_scope(LookupPaths *paths, UnitFileScope scope) {
+static int lookup_paths_init_from_scope(LookupPaths *paths,
+ UnitFileScope scope,
+ const char *root_dir) {
assert(paths);
assert(scope >= 0);
assert(scope < _UNIT_FILE_SCOPE_MAX);
@@ -57,6 +59,7 @@ static int lookup_paths_init_from_scope(LookupPaths *paths, UnitFileScope scope)
return lookup_paths_init(paths,
scope == UNIT_FILE_SYSTEM ? SYSTEMD_SYSTEM : SYSTEMD_USER,
scope == UNIT_FILE_USER,
+ root_dir,
NULL, NULL, NULL);
}
@@ -705,7 +708,7 @@ int unit_file_link(
assert(scope >= 0);
assert(scope < _UNIT_FILE_SCOPE_MAX);
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
@@ -1475,7 +1478,7 @@ int unit_file_enable(
assert(scope >= 0);
assert(scope < _UNIT_FILE_SCOPE_MAX);
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
@@ -1515,7 +1518,7 @@ int unit_file_disable(
assert(scope >= 0);
assert(scope < _UNIT_FILE_SCOPE_MAX);
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
@@ -1577,7 +1580,7 @@ int unit_file_set_default(
if (unit_name_to_type(file) != UNIT_TARGET)
return -EINVAL;
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
@@ -1612,7 +1615,11 @@ int unit_file_get_default(
char **p;
int r;
- r = lookup_paths_init_from_scope(&paths, scope);
+ assert(scope >= 0);
+ assert(scope < _UNIT_FILE_SCOPE_MAX);
+ assert(name);
+
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
@@ -1664,12 +1671,13 @@ UnitFileState unit_file_get_state(
if (!unit_name_is_valid(name, true))
return -EINVAL;
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
STRV_FOREACH(i, paths.unit_path) {
struct stat st;
+ char *partial;
free(path);
path = NULL;
@@ -1678,10 +1686,14 @@ UnitFileState unit_file_get_state(
asprintf(&path, "%s/%s/%s", root_dir, *i, name);
else
asprintf(&path, "%s/%s", *i, name);
-
if (!path)
return -ENOMEM;
+ if (root_dir)
+ partial = path + strlen(root_dir) + 1;
+ else
+ partial = path;
+
/*
* Search for a unit file in our default paths, to
* be sure, that there are no broken symlinks.
@@ -1713,7 +1725,7 @@ UnitFileState unit_file_get_state(
else if (r > 0)
return state;
- r = unit_file_can_install(&paths, root_dir, path, true);
+ r = unit_file_can_install(&paths, root_dir, partial, true);
if (r < 0 && errno != ENOENT)
return r;
else if (r > 0)
@@ -1821,7 +1833,7 @@ int unit_file_preset(
assert(scope >= 0);
assert(scope < _UNIT_FILE_SCOPE_MAX);
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
@@ -1890,7 +1902,7 @@ int unit_file_get_list(
if (root_dir && scope != UNIT_FILE_SYSTEM)
return -EINVAL;
- r = lookup_paths_init_from_scope(&paths, scope);
+ r = lookup_paths_init_from_scope(&paths, scope, root_dir);
if (r < 0)
return r;
diff --git a/src/shared/path-lookup.c b/src/shared/path-lookup.c
index 03c1380076..b62f302489 100644
--- a/src/shared/path-lookup.c
+++ b/src/shared/path-lookup.c
@@ -239,6 +239,7 @@ int lookup_paths_init(
LookupPaths *p,
SystemdRunningAs running_as,
bool personal,
+ const char *root_dir,
const char *generator,
const char *generator_early,
const char *generator_late) {
@@ -316,11 +317,9 @@ int lookup_paths_init(
}
}
- if (!path_strv_canonicalize_absolute(p->unit_path, NULL))
+ if (!path_strv_canonicalize_absolute_uniq(p->unit_path, root_dir))
return -ENOMEM;
- strv_uniq(p->unit_path);
-
if (!strv_isempty(p->unit_path)) {
_cleanup_free_ char *t = strv_join(p->unit_path, "\n\t");
if (!t)
@@ -372,15 +371,12 @@ int lookup_paths_init(
return -ENOMEM;
}
- if (!path_strv_canonicalize_absolute(p->sysvinit_path, NULL))
+ if (!path_strv_canonicalize_absolute_uniq(p->sysvinit_path, root_dir))
return -ENOMEM;
- if (!path_strv_canonicalize_absolute(p->sysvrcnd_path, NULL))
+ if (!path_strv_canonicalize_absolute_uniq(p->sysvrcnd_path, root_dir))
return -ENOMEM;
- strv_uniq(p->sysvinit_path);
- strv_uniq(p->sysvrcnd_path);
-
if (!strv_isempty(p->sysvinit_path)) {
_cleanup_free_ char *t = strv_join(p->sysvinit_path, "\n\t");
if (!t)
diff --git a/src/shared/path-lookup.h b/src/shared/path-lookup.h
index 9dee85f967..0db9bfb249 100644
--- a/src/shared/path-lookup.h
+++ b/src/shared/path-lookup.h
@@ -41,5 +41,11 @@ SystemdRunningAs systemd_running_as_from_string(const char *s) _pure_;
int user_config_home(char **config_home);
-int lookup_paths_init(LookupPaths *p, SystemdRunningAs running_as, bool personal, const char *generator, const char *generator_early, const char *generator_late);
+int lookup_paths_init(LookupPaths *p,
+ SystemdRunningAs running_as,
+ bool personal,
+ const char *root_dir,
+ const char *generator,
+ const char *generator_early,
+ const char *generator_late);
void lookup_paths_free(LookupPaths *p);
diff --git a/src/shared/path-util.c b/src/shared/path-util.c
index 36542cdb8b..5c0bf93181 100644
--- a/src/shared/path-util.c
+++ b/src/shared/path-util.c
@@ -179,36 +179,63 @@ char **path_strv_canonicalize_absolute(char **l, const char *prefix) {
STRV_FOREACH(s, l) {
char *t, *u;
+ _cleanup_free_ char *orig = NULL;
- if (!path_is_absolute(*s))
+ if (!path_is_absolute(*s)) {
+ free(*s);
continue;
+ }
if (prefix) {
- t = strappend(prefix, *s);
- free(*s);
- *s = NULL;
-
+ orig = *s;
+ t = strappend(prefix, orig);
if (!t) {
enomem = true;
continue;
}
- } else {
+ } else
t = *s;
- *s = NULL;
- }
errno = 0;
u = canonicalize_file_name(t);
if (!u) {
- if (errno == ENOENT)
- u = t;
- else {
+ if (errno == ENOENT) {
+ if (prefix) {
+ u = orig;
+ orig = NULL;
+ free(t);
+ } else
+ u = t;
+ } else {
free(t);
if (errno == ENOMEM || errno == 0)
enomem = true;
continue;
}
+ } else if (prefix) {
+ char *x;
+
+ free(t);
+ x = path_startswith(u, prefix);
+ if (x) {
+ /* restore the slash if it was lost */
+ if (!startswith(x, "/"))
+ *(--x) = '/';
+
+ t = strdup(x);
+ free(u);
+ if (!t) {
+ enomem = true;
+ continue;
+ }
+ u = t;
+ } else {
+ /* canonicalized path goes outside of
+ * prefix, keep the original path instead */
+ u = orig;
+ orig = NULL;
+ }
} else
free(t);
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index da49da7c32..517257b77f 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -4239,7 +4239,7 @@ static int enable_sysv_units(const char *verb, char **args) {
/* Processes all SysV units, and reshuffles the array so that
* afterwards only the native units remain */
- r = lookup_paths_init(&paths, SYSTEMD_SYSTEM, false, NULL, NULL, NULL);
+ r = lookup_paths_init(&paths, SYSTEMD_SYSTEM, false, arg_root, NULL, NULL, NULL);
if (r < 0)
return r;