From 93547f2812f457312a8b13b640e42f4f671ef244 Mon Sep 17 00:00:00 2001
From: Luca Boccassi <luca.boccassi@microsoft.com>
Date: Tue, 19 Jan 2021 17:11:55 +0000
Subject: [PATCH] env-util: refactor parsing helper for
 SYSTEMD_SYSEXT_HIERARCHIES out of sysext

---
 src/basic/env-util.c | 42 ++++++++++++++++++++++++++++++++++++++
 src/basic/env-util.h |  4 ++++
 src/sysext/sysext.c  | 48 ++++++--------------------------------------
 3 files changed, 52 insertions(+), 42 deletions(-)

diff --git a/src/basic/env-util.c b/src/basic/env-util.c
index 137d6b1f3cb..df24cb935d3 100644
--- a/src/basic/env-util.c
+++ b/src/basic/env-util.c
@@ -12,6 +12,7 @@
 #include "extract-word.h"
 #include "macro.h"
 #include "parse-util.h"
+#include "path-util.h"
 #include "process-util.h"
 #include "stdio-util.h"
 #include "string-util.h"
@@ -787,3 +788,44 @@ int setenv_systemd_exec_pid(bool update_only) {
 
         return 1;
 }
+
+int getenv_path_list(const char *name, char ***ret_paths) {
+        _cleanup_strv_free_ char **l = NULL;
+        const char *e;
+        char **p;
+        int r;
+
+        assert(name);
+        assert(ret_paths);
+
+        *ret_paths = NULL;
+
+        e = secure_getenv(name);
+        if (!e)
+                return 0;
+
+        r = strv_split_full(&l, e, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to parse $%s: %m", name);
+
+        STRV_FOREACH(p, l) {
+                if (!path_is_absolute(*p))
+                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "Path '%s' is not absolute, refusing.", *p);
+
+                if (!path_is_normalized(*p))
+                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "Path '%s' is not normalized, refusing.", *p);
+
+                if (path_equal(*p, "/"))
+                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "Path '%s' is the root fs, refusing.", *p);
+        }
+
+        if (strv_isempty(l))
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "No paths specified, refusing.");
+
+        *ret_paths = TAKE_PTR(l);
+        return 0;
+}
diff --git a/src/basic/env-util.h b/src/basic/env-util.h
index 79307a4a5fe..7ba8488af7f 100644
--- a/src/basic/env-util.h
+++ b/src/basic/env-util.h
@@ -59,3 +59,7 @@ int getenv_bool_secure(const char *p);
 int set_unset_env(const char *name, const char *value, bool overwrite);
 
 int setenv_systemd_exec_pid(bool update_only);
+
+/* Parses and does sanity checks on an environment variable containing
+ * PATH-like colon-separated absolute paths */
+int getenv_path_list(const char *name, char ***ret_paths);
diff --git a/src/sysext/sysext.c b/src/sysext/sysext.c
index 141c64993e8..cd824887bf7 100644
--- a/src/sysext/sysext.c
+++ b/src/sysext/sysext.c
@@ -8,6 +8,7 @@
 #include "capability-util.h"
 #include "discover-image.h"
 #include "dissect-image.h"
+#include "env-util.h"
 #include "escape.h"
 #include "fd-util.h"
 #include "fileio.h"
@@ -954,46 +955,6 @@ static int parse_argv(int argc, char *argv[]) {
         return 1;
 }
 
-static int parse_env(void) {
-        _cleanup_strv_free_ char **l = NULL;
-        const char *e;
-        char **p;
-        int r;
-
-        e = secure_getenv("SYSTEMD_SYSEXT_HIERARCHIES");
-        if (!e)
-                return 0;
-
-        /* For debugging purposes it might make sense to do this for other hierarchies than /usr/ and
-         * /opt/, but let's make that a hacker/debugging feature, i.e. env var instead of cmdline
-         * switch. */
-
-        r = strv_split_full(&l, e, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
-        if (r < 0)
-                return log_error_errno(r, "Failed to parse $SYSTEMD_SYSEXT_HIERARCHIES: %m");
-
-        STRV_FOREACH(p, l) {
-                if (!path_is_absolute(*p))
-                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                               "Hierarchy path '%s' is not absolute, refusing.", *p);
-
-                if (!path_is_normalized(*p))
-                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                               "Hierarchy path '%s' is not normalized, refusing.", *p);
-
-                if (path_equal(*p, "/"))
-                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                               "Hierarchy path '%s' is the root fs, refusing.", *p);
-        }
-
-        if (strv_isempty(l))
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "No hierarchies specified, refusing.");
-
-        strv_free_and_replace(arg_hierarchies, l);
-        return 0;
-}
-
 static int sysext_main(int argc, char *argv[]) {
 
         static const Verb verbs[] = {
@@ -1018,9 +979,12 @@ static int run(int argc, char *argv[]) {
         if (r <= 0)
                 return r;
 
-        r = parse_env();
+        /* For debugging purposes it might make sense to do this for other hierarchies than /usr/ and
+         * /opt/, but let's make that a hacker/debugging feature, i.e. env var instead of cmdline
+         * switch. */
+        r = getenv_path_list("SYSTEMD_SYSEXT_HIERARCHIES", &arg_hierarchies);
         if (r < 0)
-                return r;
+                return log_error_errno(r, "Failed to parse $SYSTEMD_SYSEXT_HIERARCHIES environment variable: %m");
 
         if (!arg_hierarchies) {
                 arg_hierarchies = strv_new("/usr", "/opt");
-- 
2.47.3