From: Filipe Brandenburger <filbranden@google.com>
Date: Tue, 9 Jun 2015 04:31:43 +0000 (-0700)
Subject: util: Introduce unquote_first_word_and_warn
X-Git-Tag: v226.4~1^2~312
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=052cd31ffd9de042f25126992294ebd6db5a67c2;p=elogind.git

util: Introduce unquote_first_word_and_warn

It will try to unquot_first_word, but if it runs into escaping problems
it will retry it adding UNQUOTE_CUNESCAPE_RELAX to the flags.  If it
succeeds on the second try, it will log a warning about it.  If it fails
both times, it will log an error.

Add test cases to confirm it behaves as expected.
---

diff --git a/src/shared/util.c b/src/shared/util.c
index 46a48c4d6..727be56f5 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -5320,6 +5320,36 @@ finish:
         return 1;
 }
 
+int unquote_first_word_and_warn(
+                const char **p,
+                char **ret,
+                UnquoteFlags flags,
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *rvalue) {
+        /* Try to unquote it, if it fails, warn about it and try again but this
+         * time using UNQUOTE_CUNESCAPE_RELAX to keep the backslashes verbatim
+         * in invalid escape sequences. */
+        const char *save;
+        int r;
+
+        save = *p;
+        r = unquote_first_word(p, ret, flags);
+        if (r < 0 && !(flags&UNQUOTE_CUNESCAPE_RELAX)) {
+                /* Retry it with UNQUOTE_CUNESCAPE_RELAX. */
+                *p = save;
+                r = unquote_first_word(p, ret, flags|UNQUOTE_CUNESCAPE_RELAX);
+                if (r < 0)
+                        log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                                   "Unbalanced quoting in command line, ignoring: \"%s\"", rvalue);
+                else
+                        log_syntax(unit, LOG_WARNING, filename, line, EINVAL,
+                                   "Invalid escape sequences in command line: \"%s\"", rvalue);
+        }
+        return r;
+}
+
 int unquote_many_words(const char **p, UnquoteFlags flags, ...) {
         va_list ap;
         char **l;
diff --git a/src/shared/util.h b/src/shared/util.h
index d465d6908..93fe000a2 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -1008,6 +1008,7 @@ typedef enum UnquoteFlags{
 } UnquoteFlags;
 
 int unquote_first_word(const char **p, char **ret, UnquoteFlags flags);
+int unquote_first_word_and_warn(const char **p, char **ret, UnquoteFlags flags, const char *unit, const char *filename, unsigned line, const char *rvalue);
 int unquote_many_words(const char **p, UnquoteFlags flags, ...) _sentinel_;
 
 int free_and_strdup(char **p, const char *s);