Move path_simplify_and_warn() to new shared/parse-helpers.c

This is a high-level function, and it belongs in libsystemd-shared. This way we
don't end up linking a separate copy into various binaries. It would even end
up in libsystemd, where it is not needed. (Maybe it'd be removed in some
optimization phase, but it's better to not rely on that.)

$ grep -l -r -a 'path is not absolute%s' build/
build/libnss_systemd.so.2
build/pam_systemd_home.so
build/test-dlopen
build/src/basic/libbasic.a.p/path-util.c.o
build/src/basic/libbasic.a
build/src/shared/libsystemd-shared-249.so
build/test-bus-error
build/libnss_mymachines.so.2
build/pam_systemd.so
build/libnss_resolve.so.2
build/libnss_myhostname.so.2
build/libsystemd.so.0.32.0
build/libudev.so.1.7.2

$ grep -l -r -a 'path is not absolute%s' build/
build/src/shared/libsystemd-shared-251.a.p/parse-helpers.c.o
build/src/shared/libsystemd-shared-251.a
build/src/shared/libsystemd-shared-251.so

No functional change.

1 files changed, 52 insertions, 0 deletions

diff --git a/src/shared/parse-helpers.c b/src/shared/parse-helpers.c
new file mode 100644
index 0000000000..5ebe366265
--- /dev/null
+++ b/src/shared/parse-helpers.c
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "log.h"
+#include "parse-helpers.h"
+#include "path-util.h"
+#include "utf8.h"
+
+int path_simplify_and_warn(
+                char *path,
+                unsigned flag,
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *lvalue) {
+
+        bool fatal = flag & PATH_CHECK_FATAL;
+
+        assert(!FLAGS_SET(flag, PATH_CHECK_ABSOLUTE | PATH_CHECK_RELATIVE));
+
+        if (!utf8_is_valid(path))
+                return log_syntax_invalid_utf8(unit, LOG_ERR, filename, line, path);
+
+        if (flag & (PATH_CHECK_ABSOLUTE | PATH_CHECK_RELATIVE)) {
+                bool absolute;
+
+                absolute = path_is_absolute(path);
+
+                if (!absolute && (flag & PATH_CHECK_ABSOLUTE))
+                        return log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL),
+                                          "%s= path is not absolute%s: %s",
+                                          lvalue, fatal ? "" : ", ignoring", path);
+
+                if (absolute && (flag & PATH_CHECK_RELATIVE))
+                        return log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL),
+                                          "%s= path is absolute%s: %s",
+                                          lvalue, fatal ? "" : ", ignoring", path);
+        }
+
+        path_simplify(path);
+
+        if (!path_is_valid(path))
+                return log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL),
+                                  "%s= path has invalid length (%zu bytes)%s.",
+                                  lvalue, strlen(path), fatal ? "" : ", ignoring");
+
+        if (!path_is_normalized(path))
+                return log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL),
+                                  "%s= path is not normalized%s: %s",
+                                  lvalue, fatal ? "" : ", ignoring", path);
+
+        return 0;
+}