basic/extract-word: add EXTRACT_UNESCAPE_SEPARATORS mode

[thirdparty/systemd.git] / src / basic / extract-word.c

diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c
index dbe64a9a58eff1765dd5285bba72806b04c2f9d5..1a53da334a23588bdb65ae8a9a51d5de3ce97872 100644 (file)
--- a/src/basic/extract-word.c
+++ b/src/basic/extract-word.c
@@ -1,21 +1,4 @@
-/***
-  This file is part of systemd.
-
-  Copyright 2010 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
+/* SPDX-License-Identifier: LGPL-2.1+ */
 
 #include <errno.h>
 #include <stdarg.h>
@@ -23,7 +6,6 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdlib.h>
-#include <string.h>
 #include <syslog.h>
 
 #include "alloc-util.h"
@@ -104,25 +86,30 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra
                                 return -EINVAL;
                         }
 
-                        if (flags & EXTRACT_CUNESCAPE) {
+                        if (flags & (EXTRACT_CUNESCAPE|EXTRACT_UNESCAPE_SEPARATORS)) {
                                 bool eight_bit = false;
                                 char32_t u;
 
-                                r = cunescape_one(*p, (size_t) -1, &u, &eight_bit);
-                                if (r < 0) {
-                                        if (flags & EXTRACT_CUNESCAPE_RELAX) {
-                                                s[sz++] = '\\';
-                                                s[sz++] = c;
-                                        } else
-                                                return -EINVAL;
-                                } else {
+                                if ((flags & EXTRACT_CUNESCAPE) &&
+                                    (r = cunescape_one(*p, (size_t) -1, &u, &eight_bit, false)) >= 0) {
+                                        /* A valid escaped sequence */
+                                        assert(r >= 1);
+
                                         (*p) += r - 1;
 
                                         if (eight_bit)
                                                 s[sz++] = u;
                                         else
                                                 sz += utf8_encode_unichar(s + sz, u);
-                                }
+                                } else if ((flags & EXTRACT_UNESCAPE_SEPARATORS) &&
+                                           strchr(separators, **p))
+                                        /* An escaped separator char */
+                                        s[sz++] = c;
+                                else if (flags & EXTRACT_CUNESCAPE_RELAX) {
+                                        s[sz++] = '\\';
+                                        s[sz++] = c;
+                                } else
+                                        return -EINVAL;
                         } else
                                 s[sz++] = c;
 
@@ -152,7 +139,7 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra
                         for (;; (*p)++, c = **p) {
                                 if (c == 0)
                                         goto finish_force_terminate;
-                                else if ((c == '\'' || c == '"') && (flags & EXTRACT_QUOTES)) {
+                                else if (IN_SET(c, '\'', '"') && (flags & EXTRACT_UNQUOTE)) {
                                         quote = c;
                                         break;
                                 } else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
@@ -193,8 +180,7 @@ finish:
 
 finish_force_next:
         s[sz] = 0;
-        *ret = s;
-        s = NULL;
+        *ret = TAKE_PTR(s);
 
         return 1;
 }
@@ -227,8 +213,8 @@ int extract_first_word_and_warn(
                 *p = save;
                 r = extract_first_word(p, ret, separators, flags|EXTRACT_CUNESCAPE_RELAX);
                 if (r >= 0) {
-                        /* It worked this time, hence it must have been an invalid escape sequence we could correct. */
-                        log_syntax(unit, LOG_WARNING, filename, line, EINVAL, "Invalid escape sequences in line, correcting: \"%s\"", rvalue);
+                        /* It worked this time, hence it must have been an invalid escape sequence. */
+                        log_syntax(unit, LOG_WARNING, filename, line, EINVAL, "Ignoring unknown escape sequences: \"%s\"", *ret);
                         return r;
                 }
 
@@ -241,7 +227,12 @@ int extract_first_word_and_warn(
         return log_syntax(unit, LOG_ERR, filename, line, r, "Unable to decode word \"%s\", ignoring: %m", rvalue);
 }
 
-int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) {
+/* We pass ExtractFlags as unsigned int (to avoid undefined behaviour when passing
+ * an object that undergoes default argument promotion as an argument to va_start).
+ * Let's make sure that ExtractFlags fits into an unsigned int. */
+assert_cc(sizeof(enum ExtractFlags) <= sizeof(unsigned));
+
+int extract_many_words(const char **p, const char *separators, unsigned flags, ...) {
         va_list ap;
         char **l;
         int n = 0, i, c, r;