- Simplify the procedure of retrieving XML-data from the kernel.

- Fix a number of potential memory leaks in libgeom related to doing realloc
  without freeing old pointer if things go wrong.
- Fix a number of places in libgeom where malloc and calloc return values
  were not checked.
- Check malloc return value and provide sufficient warning messages when XML
  parsing fails.

PR:		kern/83464
Submitted by:	Dan Lukes <dan - at - obluda.cz>
Approved by:	kib (mentor)

1 files changed, 13 insertions, 19 deletions

diff --git a/lib/libgeom/geom_getxml.c b/lib/libgeom/geom_getxml.c
index 68ff91b..b27696d 100644
--- a/lib/libgeom/geom_getxml.c
+++ b/lib/libgeom/geom_getxml.c
@@ -39,28 +39,22 @@ char *
 geom_getxml()
 {
 	char *p;
-	size_t l;
-	int i;
+	size_t l = 0;
+	int mib[3];
+	size_t sizep;
 
-	l = 1024 * 1024;	/* Start big, realloc back */
+	sizep = sizeof(mib) / sizeof(*mib);
+	if (sysctlnametomib("kern.geom.confxml", mib, &sizep) != 0)
+		return (NULL);
+	if (sysctl(mib, sizep, NULL, &l, NULL, 0) != 0)
+		return (NULL);
+	l += 4096;
 	p = malloc(l);
-	if (p) {
-		i = sysctlbyname("kern.geom.confxml", p, &l, NULL, 0);
-		if (i == 0) {
-			p = realloc(p, strlen(p) + 1);
-			return (p);
-		}
+	if (p == NULL)
+		return (NULL);
+	if (sysctl(mib, sizep, p, &l, NULL, 0) != 0) {
 		free(p);
-	}
-	l = 0;
-	i = sysctlbyname("kern.geom.confxml", NULL, &l, NULL, 0);
-	if (i != 0)
 		return (NULL);
-	p = malloc(l + 4096);
-	i = sysctlbyname("kern.geom.confxml", p, &l, NULL, 0);
-	if (i == 0) {
-		p = realloc(p, strlen(p) + 1);
-		return (p);
 	}
-	return (NULL);
+	return (reallocf(p, strlen(p) + 1));
 }