Re: [Libvir] [PATCH] Fix MAC address parsing for 1-digit case
Hi, Jim and Rich
Thank you for your suggestions.
I apply the following changes to the patch.
1) Initialize errno to 0 before the loop.
2) Use isxdigit instead of isdigit and isalpha, and add a comment.
3) Test errno != 0.
4) Add a terminating NUL check.
5) the MAC address function go in file src/util.c.
Thanks,
Signed-off-by: Hiroyuki Kaguchi <fj7025cf(a)aa.jp.fujitsu.com>
Index: src/util.c
===================================================================
RCS file: /data/cvs/libvirt/src/util.c,v
retrieving revision 1.25
diff -u -r1.25 util.c
--- src/util.c 3 Mar 2008 20:39:52 -0000 1.25
+++ src/util.c 19 Mar 2008 06:29:15 -0000
@@ -688,6 +688,53 @@
return (c > d ? 1 : c < d ? -1 : 0);
}
+/**
+ * virParseMacAddr:
+ * @str: pointer to the char used
+ * @addr: MAC address
+ *
+ * Parse a MAC address
+ *
+ * Returns 0 or -1 in case of error.
+ */
+int
+virParseMacAddr(const char* str, unsigned char *addr)
+{
+ int i;
+
+ errno = 0;
+ for (i = 0; i < 6; i++) {
+ char *end_ptr;
+ unsigned long result;
+
+ /* This is solely to avoid accepting the leading
+ * space or "+" that strtoul would otherwise accept.
+ */
+ if (!isxdigit(*str))
+ break;
+
+ result = strtoul(str, &end_ptr, 16);
+
+ if ((end_ptr - str) < 1 || 2 < (end_ptr - str) ||
+ (errno != 0) ||
+ (0xFF < result))
+ break;
+
+ addr[i] = (unsigned char) result;
+
+ if (*end_ptr != ':') {
+ if (i == 5 && *end_ptr == '\0')
+ return 0;
+
+ break;
+ }
+
+ str = end_ptr + 1;
+ }
+
+ return -1;
+}
+
/*
* Local variables:
* indent-tabs-mode: nil
Index: src/util.h
===================================================================
RCS file: /data/cvs/libvirt/src/util.h,v
retrieving revision 1.13
diff -u -r1.13 util.h
--- src/util.h 27 Feb 2008 16:14:44 -0000 1.13
+++ src/util.h 19 Mar 2008 06:29:15 -0000
@@ -85,4 +85,6 @@
void virSkipSpaces(const char **str);
int virParseNumber(const char **str);
+int virParseMacAddr(const char* str, unsigned char *addr);
+
#endif /* __VIR_UTIL_H__ */
Index: src/xml.c
===================================================================
RCS file: /data/cvs/libvirt/src/xml.c,v
retrieving revision 1.113
diff -u -r1.113 xml.c
--- src/xml.c 27 Feb 2008 04:35:08 -0000 1.113
+++ src/xml.c 19 Mar 2008 06:29:16 -0000
@@ -1233,22 +1233,8 @@
virBufferAddLit(buf, "(vif ");
if (mac != NULL) {
- unsigned int addr[12];
- int tmp = sscanf((const char *) mac,
- "%01x%01x:%01x%01x:%01x%01x:%01x%01x:%01x%01x:%01x%01x",
- (unsigned int *) &addr[0],
- (unsigned int *) &addr[1],
- (unsigned int *) &addr[2],
- (unsigned int *) &addr[3],
- (unsigned int *) &addr[4],
- (unsigned int *) &addr[5],
- (unsigned int *) &addr[6],
- (unsigned int *) &addr[7],
- (unsigned int *) &addr[8],
- (unsigned int *) &addr[9],
- (unsigned int *) &addr[10],
- (unsigned int *) &addr[11]);
- if (tmp != 12 || strlen((const char *) mac) != 17) {
+ unsigned char addr[6];
+ if (virParseMacAddr((const char*) mac, addr) == -1) {
virXMLError(conn, VIR_ERR_INVALID_MAC, (const char *) mac, 0);
goto error;
}