tree-wide: refuse too long strings earlier in specifier_printf()

We usually call specifier_printf() and then check the validity of
the result. In many cases, validity checkers, e.g. path_is_valid(),
refuse too long strings. This makes specifier_printf() refuse such
long results earlier.

Moreover, unit_full_string() and description field in sysuser now
refuse results longer than LONG_LINE_MAX. config_parse() already
refuses the line longer than LONG_LINE_MAX. Hence, it should be ok
to set the same value as the maximum length of the resolved string.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/shared/install-printf.h b/src/shared/install-printf.h
index 34e129413e..13a39829e9 100644
--- a/src/shared/install-printf.h
+++ b/src/shared/install-printf.h
@@ -2,5 +2,12 @@
 #pragma once
 
 #include "install.h"
+#include "unit-name.h"
 
-int install_full_printf(const UnitFileInstallInfo *i, const char *format, char **ret);
+int install_full_printf_internal(const UnitFileInstallInfo *i, const char *format, size_t max_length, char **ret);
+static inline int install_name_printf(const UnitFileInstallInfo *i, const char *format, char **ret) {
+        return install_full_printf_internal(i, format, UNIT_NAME_MAX, ret);
+}
+static inline int install_path_printf(const UnitFileInstallInfo *i, const char *format, char **ret) {
+        return install_full_printf_internal(i, format, PATH_MAX-1, ret);
+}