libmultipath: config parser: fix corner case for double quotes

A corner case of the previous patch are strings starting with a double quote,
such as '"prepended to itself is false" prepended to itself is false' or
'"" is the empty string', and in particular, the string '"' ("\"" in C
notation), which is indistinguishable from the "QUOTE" token in the parsed strvec.

This patch fixes that by introducing a special token that can't occur as part
of a normal string to indicate the beginning and end of a quoted string.

'"' is admittedly not a very likely keyword value for multipath.conf, but
a) this is a matter of correctness, b) we didn't think of '2.5"' before, either, and
c) the (*str != '"') expressions would need to be patched anyway to fix the
'string starting with "' case.

Signed-off-by: Martin Wilck <mwilck@suse.com>

diff --git a/libmultipath/parser.c b/libmultipath/parser.c
index 21151a1..cee1c96 100644 (file)
--- a/libmultipath/parser.c
+++ b/libmultipath/parser.c
@@ -186,6 +186,12 @@ snprint_keyword(char *buff, int len, char *fmt, struct keyword *kw,
        return fwd;
 }
 
+static const char quote_marker[] = { '\0', '"', '\0' };
+bool is_quote(const char* token)
+{
+       return !memcmp(token, quote_marker, sizeof(quote_marker));
+}
+
 vector
 alloc_strvec(char *string)
 {
@@ -227,13 +233,12 @@ alloc_strvec(char *string)
                start = cp;
                if (*cp == '"' && !(in_string && *(cp + 1) == '"')) {
                        cp++;
-                       token = MALLOC(2);
+                       token = MALLOC(sizeof(quote_marker));
 
                        if (!token)
                                goto out;
 
-                       *(token) = '"';
-                       *(token + 1) = '\0';
+                       memcpy(token, quote_marker, sizeof(quote_marker));
                        if (in_string)
                                in_string = 0;
                        else
@@ -324,13 +329,13 @@ set_value(vector strvec)
                        (char *)VECTOR_SLOT(strvec, 0));
                return NULL;
        }
-       size = strlen(str);
-       if (size == 0) {
-               condlog(0, "option '%s' has empty value",
-                       (char *)VECTOR_SLOT(strvec, 0));
-               return NULL;
-       }
-       if (*str != '"') {
+       if (!is_quote(str)) {
+               size = strlen(str);
+               if (size == 0) {
+                       condlog(0, "option '%s' has empty value",
+                               (char *)VECTOR_SLOT(strvec, 0));
+                       return NULL;
+               }
                alloc = MALLOC(sizeof (char) * (size + 1));
                if (alloc)
                        memcpy(alloc, str, size);
@@ -354,7 +359,7 @@ set_value(vector strvec)
                                (char *)VECTOR_SLOT(strvec, 0));
                        return NULL;
                }
-               if (*str == '"')
+               if (is_quote(str))
                        break;
                tmp = alloc;
                /* The first +1 is for the NULL byte. The rest are for the
@@ -460,7 +465,7 @@ validate_config_strvec(vector strvec, char *file)
                        (char *)VECTOR_SLOT(strvec, 0), line_nr, file);
                return -1;
        }
-       if (*str != '"') {
+       if (!is_quote(str)) {
                if (VECTOR_SIZE(strvec) > 2)
                        condlog(0, "ignoring extra data starting with '%s' on line %d of %s", (char *)VECTOR_SLOT(strvec, 2), line_nr, file);
                return 0;
@@ -472,7 +477,7 @@ validate_config_strvec(vector strvec, char *file)
                                line_nr, file);
                        return -1;
                }
-               if (*str == '"') {
+               if (is_quote(str)) {
                        if (VECTOR_SIZE(strvec) > i + 1)
                                condlog(0, "ignoring extra data starting with '%s' on line %d of %s", (char *)VECTOR_SLOT(strvec, (i + 1)), line_nr, file);
                        return 0;

diff --git a/libmultipath/parser.h b/libmultipath/parser.h
index 0a74750..62906e9 100644 (file)
--- a/libmultipath/parser.h
+++ b/libmultipath/parser.h
@@ -81,5 +81,6 @@ extern int process_file(struct config *conf, char *conf_file);
 extern struct keyword * find_keyword(vector keywords, vector v, char * name);
 int snprint_keyword(char *buff, int len, char *fmt, struct keyword *kw,
                    const void *data);
+bool is_quote(const char* token);
 
 #endif

diff --git a/multipathd/cli.c b/multipathd/cli.c
index f10f862..bf25b41 100644 (file)
--- a/multipathd/cli.c
+++ b/multipathd/cli.c
@@ -279,7 +279,7 @@ get_cmdvec (char * cmd, vector *v)
        }
 
        vector_foreach_slot(strvec, buff, i) {
-               if (*buff == '"')
+               if (is_quote(buff))
                        continue;
                if (get_param) {
                        get_param = 0;

diff --git a/tests/parser.c b/tests/parser.c
index 8e73ceb..a7e7598 100644 (file)
--- a/tests/parser.c
+++ b/tests/parser.c
@@ -34,11 +34,6 @@
 /* Stop parsing at 2nd quote */
 #define TWO_QUOTES_ONLY 0
 
-static bool is_quote(const char *s)
-{
-       return *s == '"';
-}
-
 static char *test_file = "test.conf";
 
 /* Missing declaration */