core: refactor parsing in match_device_s390_subchannels_parse()

Changes:

  - match_device_s390_subchannels_parse() should accept un-initialized
    arguments a,b,c, as they are striclty output arguments (without
    transfering ownership).
  - the output arguments should be set if (and only if) the function
    succeeds. That is, move assigning the output arguments to the end.
  - increase the BUFSIZE. It's unclear why choosing 10. Probably that
    was already sufficient as a subchannel looks like
    "0.0.f5f0,0.0.f5f1,0.0.f5f2". Still, increase it to be ample.
    If we want to restrict the parsing based on the lenght of the input,
    that should be done explicitly (but that seems not desirable).
  - use _nm_utils_ascii_str_to_int64() which checks that the range
    of the values fits in guint32.

It seems wrong that match_device_s390_subchannels_eval() only compares
the first of up to three subchannels. But leave it as is for now.

1 files changed, 32 insertions, 35 deletions

diff --git a/src/nm-core-utils.c b/src/nm-core-utils.c
index 1501ef984e..631540a17c 100644
--- a/src/nm-core-utils.c
+++ b/src/nm-core-utils.c
@@ -1232,67 +1232,64 @@ typedef struct {
 } MatchDeviceData;
 
 static gboolean
-match_device_s390_subchannels_parse (const char *s390_subchannels, guint32 *a, guint32 *b, guint32 *c)
+match_device_s390_subchannels_parse (const char *s390_subchannels, guint32 *out_a, guint32 *out_b, guint32 *out_c)
 {
-	const int BUFSIZE = 10;
-	long unsigned int tmp;
+	const int BUFSIZE = 30;
 	char buf[BUFSIZE + 1];
-	const char *p = s390_subchannels;
-	int i = 0;
+	guint i = 0;
 	char *pa = NULL, *pb = NULL, *pc = NULL;
+	gint64 a, b, c;
 
 	nm_assert (s390_subchannels);
-	nm_assert (a != NULL);
-	nm_assert (*a == 0);
-	nm_assert (b != NULL);
-	nm_assert (*b == 0);
-	nm_assert (c != NULL);
-	nm_assert (*c == 0);
-
-	/* sanity check */
+	nm_assert (out_a);
+	nm_assert (out_b);
+	nm_assert (out_c);
+
 	if (!g_ascii_isxdigit (s390_subchannels[0]))
 		return FALSE;
 
 	/* Get the first channel */
-	while (*p && (*p != ',')) {
-		if (!g_ascii_isxdigit (*p) && (*p != '.'))
+	for (i = 0; s390_subchannels[i]; i++) {
+		char ch = s390_subchannels[i];
+
+		if (!g_ascii_isxdigit (ch) && ch != '.') {
+			if (ch == ',') {
+				/* FIXME: currently we consider the first channel and ignore
+				 * everything after the first ',' separator. Maybe we should
+				 * validate all present channels? */
+				break;
+			}
 			return FALSE;  /* Invalid chars */
+		}
 		if (i >= BUFSIZE)
 			return FALSE;  /* Too long to be a subchannel */
-		buf[i++] = *p++;
+		buf[i] = ch;
 	}
 	buf[i] = '\0';
 
 	/* and grab each of its elements, there should be 3 */
 	pa = &buf[0];
-	pb = strchr (buf, '.');
+	pb = strchr (pa, '.');
 	if (pb)
 		pc = strchr (pb + 1, '.');
-	if (!pa || !pb || !pc)
+	if (!pb || !pc)
 		return FALSE;
-
-	/* Split the string */
 	*pb++ = '\0';
 	*pc++ = '\0';
 
-	errno = 0;
-	tmp = strtoul (pa, NULL, 16);
-	if (errno)
+	a = _nm_utils_ascii_str_to_int64 (pa, 16, 0, G_MAXUINT32, -1);
+	if (a == -1)
 		return FALSE;
-	*a = (guint32) tmp;
-
-	errno = 0;
-	tmp = strtoul (pb, NULL, 16);
-	if (errno)
+	b = _nm_utils_ascii_str_to_int64 (pb, 16, 0, G_MAXUINT32, -1);
+	if (b == -1)
 		return FALSE;
-	*b = (guint32) tmp;
-
-	errno = 0;
-	tmp = strtoul (pc, NULL, 16);
-	if (errno)
+	c = _nm_utils_ascii_str_to_int64 (pc, 16, 0, G_MAXUINT32, -1);
+	if (c == -1)
 		return FALSE;
-	*c = (guint32) tmp;
 
+	*out_a = (guint32) a;
+	*out_b = (guint32) b;
+	*out_c = (guint32) c;
 	return TRUE;
 }
 
@@ -1300,7 +1297,7 @@ static gboolean
 match_data_s390_subchannels_eval (const char *spec_str,
                                   MatchDeviceData *match_data)
 {
-	guint32 a = 0, b = 0, c = 0;
+	guint32 a, b, c;
 
 	if (G_UNLIKELY (!match_data->s390_subchannels.is_parsed)) {
 		match_data->s390_subchannels.is_parsed = TRUE;