Escape double quotes and backslashes in external metadata and config data.

Add functions for escaping double quotes in strings.
Rename count_chars_len to count_chars.

WHATS_NEW

@@ -1,5 +1,8 @@
 Version 2.02.34 -
 ===================================
+  Escape double quotes and backslashes in external metadata and config data.
+  Add functions for escaping double quotes in strings.
+  Rename count_chars_len to count_chars.
   Use return_0 in a couple more places.
   Correct a function name typo in _line_append error message.
   Include limits.h in clvmd so it compiles with newer headers.

lib/config/config.c

@@ -34,7 +34,8 @@
 enum {
 	TOK_INT,
 	TOK_FLOAT,
-	TOK_STRING,
+	TOK_STRING,		/* Single quotes */
+	TOK_STRING_ESCAPED,	/* Double quotes */
 	TOK_EQ,
 	TOK_SECTION_B,
 	TOK_SECTION_E,
@@ -401,9 +402,16 @@ static int _line_end(struct output_line *outline)
 
 static int _write_value(struct output_line *outline, struct config_value *v)
 {
+	char *buf;
+
 	switch (v->type) {
 	case CFG_STRING:
-		line_append("\"%s\"", v->v.str);
+		if (!(buf = alloca(escaped_len(v->v.str)))) {
+			log_error("temporary stack allocation for a config "
+				  "string failed");
+			return 0;
+		}
+		line_append("\"%s\"", escape_double_quotes(buf, v->v.str));
 		break;
 
 	case CFG_FLOAT:
@@ -644,6 +652,17 @@ static struct config_value *_type(struct parser *p)
 		match(TOK_STRING);
 		break;
 
+	case TOK_STRING_ESCAPED:
+		v->type = CFG_STRING;
+
+		p->tb++, p->te--;	/* strip "'s */
+		if (!(v->v.str = _dup_tok(p)))
+			return_0;
+		unescape_double_quotes(v->v.str);
+		p->te++;
+		match(TOK_STRING_ESCAPED);
+		break;
+
 	default:
 		log_error("Parse error at byte %" PRIptrdiff_t " (line %d): expected a value",
 			  p->tb - p->fb + 1, p->line);
@@ -714,7 +733,7 @@ static void _get_token(struct parser *p, int tok_prev)
 		break;
 
 	case '"':
-		p->t = TOK_STRING;
+		p->t = TOK_STRING_ESCAPED;
 		p->te++;
 		while ((p->te != p->fe) && (*p->te) && (*p->te != '"')) {
 			if ((*p->te == '\\') && (p->te + 1 != p->fe) &&
@@ -1232,7 +1251,7 @@ static unsigned _count_tokens(const char *str, unsigned len, int type)
 
 	c = _token_type_to_char(type);
 
-	return count_chars_len(str, len, c);
+	return count_chars(str, len, c);
 }
 
 /*

lib/filters/filter-persistent.c

@@ -18,6 +18,7 @@
 #include "dev-cache.h"
 #include "filter-persistent.h"
 #include "lvm-file.h"
+#include "lvm-string.h"
 
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -142,6 +143,7 @@ static void _write_array(struct pfilter *pf, FILE *fp, const char *path,
 {
 	void *d;
 	int first = 1;
+	char *buf, *str;
 	struct dm_hash_node *n;
 
 	for (n = dm_hash_get_first(pf->devices); n;
@@ -158,7 +160,13 @@ static void _write_array(struct pfilter *pf, FILE *fp, const char *path,
 			first = 0;
 		}
 
-		fprintf(fp, "\t\t\"%s\"", dm_hash_get_key(pf->devices, n));
+		str = dm_hash_get_key(pf->devices, n);
+		if (!(buf = alloca(escaped_len(str)))) {
+			log_error("persistent filter device path stack "
+				  "allocation failed");
+			return;
+		}
+		fprintf(fp, "\t\t\"%s\"", escape_double_quotes(buf, str));
 	}
 
 	if (!first)

lib/format_text/export.c

@@ -296,6 +296,7 @@ int out_text(struct formatter *f, const char *fmt, ...)
 static int _print_header(struct formatter *f,
 			 const char *desc)
 {
+	char *buf;
 	time_t t;
 
 	t = time(NULL);
@@ -305,7 +306,12 @@ static int _print_header(struct formatter *f,
 	outf(f, FORMAT_VERSION_FIELD " = %d", FORMAT_VERSION_VALUE);
 	outnl(f);
 
-	outf(f, "description = \"%s\"", desc);
+	if (!(buf = alloca(escaped_len(desc)))) {
+		log_error("temporary stack allocation for description"
+			  "string failed");
+		return 0;
+	}
+	outf(f, "description = \"%s\"", escape_double_quotes(buf, desc));
 	outnl(f);
 	outf(f, "creation_host = \"%s\"\t# %s %s %s %s %s", _utsname.nodename,
 	     _utsname.sysname, _utsname.nodename, _utsname.release,
@@ -370,6 +376,7 @@ static int _print_pvs(struct formatter *f, struct volume_group *vg)
 	struct pv_list *pvl;
 	struct physical_volume *pv;
 	char buffer[4096];
+	char *buf;
 	const char *name;
 
 	outf(f, "physical_volumes {");
@@ -389,7 +396,15 @@ static int _print_pvs(struct formatter *f, struct volume_group *vg)
 			return_0;
 
 		outf(f, "id = \"%s\"", buffer);
-		if (!out_hint(f, "device = \"%s\"", pv_dev_name(pv)))
+
+		if (!(buf = alloca(escaped_len(pv_dev_name(pv))))) {
+			log_error("temporary stack allocation for device name"
+				  "string failed");
+			return 0;
+		}
+
+		if (!out_hint(f, "device = \"%s\"",
+			      escape_double_quotes(buf, pv_dev_name(pv))))
 			return_0;
 		outnl(f);
 

lib/misc/lvm-string.c

@@ -39,16 +39,16 @@ int emit_to_buffer(char **buffer, size_t *size, const char *fmt, ...)
  * Count occurences of 'c' in 'str' until we reach a null char.
  *
  * Returns:
- *  len - incremented for each char we encounter, whether 'c' or not.
- *  count - number of occurrences of 'c'
+ *  len - incremented for each char we encounter.
+ *  count - number of occurrences of 'c' and 'c2'.
  */
-void count_chars(const char *str, size_t *len, int *count,
-		 const int c)
+static void _count_chars(const char *str, size_t *len, int *count,
+			 const int c1, const int c2)
 {
 	const char *ptr;
 
 	for (ptr = str; *ptr; ptr++, (*len)++)
-		if (*ptr == c)
+		if (*ptr == c1 || *ptr == c2)
 			(*count)++;
 }
 
@@ -58,7 +58,7 @@ void count_chars(const char *str, size_t *len, int *count,
  * Returns:
  *   Number of occurrences of 'c'
  */
-unsigned count_chars_len(const char *str, size_t len, const int c)
+unsigned count_chars(const char *str, size_t len, const int c)
 {
 	size_t i;
 	unsigned count = 0;
@@ -70,17 +70,62 @@ unsigned count_chars_len(const char *str, size_t len, const int c)
 	return count;
 }
 
+/*
+ * Length of string after escaping double quotes and backslashes.
+ */
+size_t escaped_len(const char *str)
+{
+	size_t len = 1;
+	int count = 0;
+
+	_count_chars(str, &len, &count, '\"', '\\');
+
+	return count + len;
+}
+
+/*
+ * Copies a string, quoting orig_char with quote_char.
+ * Optionally also quote quote_char.
+ */
+static void _quote_characters(char **out, const char *src,
+			      const int orig_char, const int quote_char,
+			      int quote_quote_char)
+{
+	while (*src) {
+		if (*src == orig_char ||
+		    (*src == quote_char && quote_quote_char))
+			*(*out)++ = quote_char;
+
+		*(*out)++ = *src++;
+	}
+}
+
+/*
+ * Unquote orig_char in string.
+ * Also unquote quote_char.
+ */
+static void _unquote_characters(char *src, const int orig_char,
+				const int quote_char)
+{
+	char *out = src;
+
+	while (*src) {
+		if (*src == quote_char &&
+		    (*(src + 1) == orig_char || *(src + 1) == quote_char))
+			src++;
+
+		*out++ = *src++;
+	}
+
+	*out = '\0';
+}
+
 /*
  * Copies a string, quoting hyphens with hyphens.
  */
 static void _quote_hyphens(char **out, const char *src)
 {
-	while (*src) {
-		if (*src == '-')
-			*(*out)++ = '-';
-
-		*(*out)++ = *src++;
-	}
+	return _quote_characters(out, src, '-', '-', 0);
 }
 
 /*
@@ -93,11 +138,11 @@ char *build_dm_name(struct dm_pool *mem, const char *vgname,
 	int hyphens = 1;
 	char *r, *out;
 
-	count_chars(vgname, &len, &hyphens, '-');
-	count_chars(lvname, &len, &hyphens, '-');
+	_count_chars(vgname, &len, &hyphens, '-', 0);
+	_count_chars(lvname, &len, &hyphens, '-', 0);
 
 	if (layer && *layer) {
-		count_chars(layer, &len, &hyphens, '-');
+		_count_chars(layer, &len, &hyphens, '-', 0);
 		hyphens++;
 	}
 
@@ -125,6 +170,27 @@ char *build_dm_name(struct dm_pool *mem, const char *vgname,
 	return r;
 }
 
+/*
+ * Copies a string, quoting double quotes with backslashes.
+ */
+char *escape_double_quotes(char *out, const char *src)
+{
+	char *buf = out;
+
+	_quote_characters(&buf, src, '\"', '\\', 1);
+	*buf = '\0';
+
+	return out;
+}
+
+/*
+ * Undo quoting in situ.
+ */
+void unescape_double_quotes(char *src)
+{
+	_unquote_characters(src, '\"', '\\');
+}
+
 /*
  * Device layer names are all of the form <vg>-<lv>-<layer>, any
  * other hyphens that appear in these names are quoted with yet

lib/misc/lvm-string.h

@@ -31,8 +31,27 @@ char *build_dm_name(struct dm_pool *mem, const char *vg,
 
 int validate_name(const char *n);
 
-void count_chars(const char *str, size_t *len, int *count,
-		 const int c);
-unsigned count_chars_len(const char *str, size_t len, const int c);
+/*
+ * Returns number of occurrences of c in first len characters of str.
+ */
+unsigned count_chars(const char *str, size_t len, const int c);
+
+/*
+ * Returns what length of escaped string would be including terminating NUL.
+ */
+size_t escaped_len(const char *str);
+
+/*
+ * Copies a string from src to out. 
+ * Double quotation marks and backslashes are quoted with a backslash.
+ * Caller must ensure *out has enough space - see escaped_len().
+ * Returns *out.
+ */
+char *escape_double_quotes(char *out, const char *src);
+
+/*
+ * Removes quoting of double quotation marks and backslashes in situ.
+ */
+void unescape_double_quotes(char *src);
 
 #endif