svn commit: r312098 - stable/10/contrib/bsnmp/gensnmpdef

[Ngie Cooper]

Author: ngie
Date: Sat Jan 14 00:36:48 2017
New Revision: 312098
URL: https://svnweb.freebsd.org/changeset/base/312098

Log:
  MFC r311750,r311754,r311757:
  
  r311750:
  
  Check result from smiGetFirstNode and smiGetNodeByOID
  
  This avoids a segfault with malformed or unanticipated files,
  like IPV6-TC.txt (a file containing just TEXTUAL-CONVENTIONS).
  
  Found with:	gensnmpdef /usr/local/share/snmp/mibs/IPV6-TC.txt
  
  r311754:
  
  Use calloc instead of malloc + memset(.., 0, ..)
  
  r311757:
  
  Similar to r311750, check for the result from smiGetModule to avoid a segfault
  when dereferencing a NULL pointer later on.
  
  Choose to just check for the NULL pointer in the next for-loop for now to fix
  the issue with a minimal amount of code churn
  
  sys/queue.h use here would make more sense than using a static table

Modified:
  stable/10/contrib/bsnmp/gensnmpdef/gensnmpdef.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/contrib/bsnmp/gensnmpdef/gensnmpdef.c
==============================================================================
--- stable/10/contrib/bsnmp/gensnmpdef/gensnmpdef.c	Sat Jan 14 00:33:07 2017	(r312097)
+++ stable/10/contrib/bsnmp/gensnmpdef/gensnmpdef.c	Sat Jan 14 00:36:48 2017	(r312098)
@@ -126,9 +126,11 @@ open_node(const SmiNode *n, u_int level,
 
 	while (level < n->oidlen - 1) {
 		if (level >= cut) {
+			n1 = smiGetNodeByOID(level + 1, n->oid);
+			if (n1 == NULL)
+				continue;
 			pindent(level);
 			printf("(%u", n->oid[level]);
-			n1 = smiGetNodeByOID(level + 1, n->oid);
 			printf(" ");
 			print_name(n1);
 			printf("\n");
@@ -397,12 +399,11 @@ static void
 save_typdef(char *name)
 {
 	struct tdef *t;
-	t = malloc(sizeof(struct tdef));
 
+	t = calloc(1, sizeof(struct tdef));
 	if (t == NULL)
 		err(1, NULL);
 
-	memset(t, 0 , sizeof(struct tdef));
 	t->name = name;
 	SLIST_INSERT_HEAD(&tdefs, t, link);
 }
@@ -559,7 +560,11 @@ main(int argc, char *argv[])
 	level = 0;
 	last = NULL;
 	for (opt = 0; opt < argc; opt++) {
+		if (mods[opt] == NULL) /* smiGetModule failed above */
+			continue;
 		n = smiGetFirstNode(mods[opt], SMI_NODEKIND_ANY);
+		if (n == NULL)
+			continue;
 		for (;;) {
 			if (do_typedef == 0) {
 				level = open_node(n, level, &last);