[GitHub] [nuttx] zhhyu7 commented on a diff in pull request #8864: netlink: add RTM_NEWADDR, RTM_DELADDR and RTM_GETADDR

["zhhyu7 (via GitHub)" <gi...@apache.org>]

zhhyu7 commented on code in PR #8864:
URL: https://github.com/apache/nuttx/pull/8864#discussion_r1143192778


##########
net/netlink/nlattr.c:
##########
@@ -0,0 +1,324 @@
+/****************************************************************************
+ * net/netlink/nlattr.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+#include <unistd.h>
+
+#include <nuttx/net/netlink.h>
+
+#include "netlink.h"
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+#ifdef CONFIG_NETLINK_VALIDATE_POLICY
+static const uint8_t g_nla_attr_len[NLA_TYPE_MAX + 1] =
+{
+  0,
+  sizeof(uint8_t),
+  sizeof(uint16_t),
+  sizeof(uint32_t),
+  sizeof(uint64_t),
+  0, 0, 0, 0, 0, 0, 0,
+  sizeof(int8_t),
+  sizeof(int16_t),
+  sizeof(int32_t),
+  sizeof(int64_t),
+};
+
+static const uint8_t g_nla_attr_minlen[NLA_TYPE_MAX + 1] =
+{
+  0,
+  sizeof(uint8_t),
+  sizeof(uint16_t),
+  sizeof(uint32_t),
+  sizeof(uint64_t),
+  0, 0,
+  sizeof(uint64_t),
+  NLA_HDRLEN,
+  0, 0, 0,
+  sizeof(int8_t),
+  sizeof(int16_t),
+  sizeof(int32_t),
+  sizeof(int64_t),
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static int validate_nla_bitfield32(FAR const struct nlattr *nla,
+                                   FAR uint32_t *valid_flags_mask)
+{
+  FAR const struct nla_bitfield32 *bf = nla_data(nla);
+
+  if (!valid_flags_mask)
+    {
+      return -EINVAL;
+    }
+
+  /* disallow invalid bit selector */
+
+  if (bf->selector & ~*valid_flags_mask)
+    {
+      return -EINVAL;
+    }
+
+  /* disallow invalid bit values */
+
+  if (bf->value & ~*valid_flags_mask)
+    {
+      return -EINVAL;
+    }
+
+  /* disallow valid bit values that are not selected */
+
+  if (bf->value & ~bf->selector)
+    {
+      return -EINVAL;
+    }
+
+  return 0;
+}
+
+static int validate_nla(FAR const struct nlattr *nla, int maxtype,
+                        FAR const struct nla_policy *policy)
+{
+  FAR const struct nla_policy *pt;
+  int minlen = 0;
+  int attrlen = nla_len(nla);
+  int type = nla_type(nla);
+
+  if (type <= 0 || type > maxtype)
+    {
+      return -EINVAL;
+    }
+
+  pt = &policy[type];
+
+  DEBUGASSERT(pt->type <= NLA_TYPE_MAX);
+
+  if (g_nla_attr_len[pt->type] && attrlen != g_nla_attr_len[pt->type])
+    {
+      nwarn("netlink: '%d': attribute type %d has an invalid length.\n",
+            getpid(), type);
+      return -EINVAL;
+    }
+
+  switch (pt->type)
+    {
+      case NLA_FLAG:
+        if (attrlen > 0)
+          {
+            return -ERANGE;
+          }
+        break;
+
+      case NLA_BITFIELD32:
+        if (attrlen != sizeof(struct nla_bitfield32))
+          {
+            return -ERANGE;
+          }
+
+        return validate_nla_bitfield32(nla, pt->validation_data);
+
+      case NLA_NUL_STRING:
+        if (pt->len)
+          {
+            minlen = MIN(attrlen, pt->len + 1);
+          }
+        else
+          {
+            minlen = attrlen;
+          }
+
+        if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
+          {
+            return -EINVAL;
+          }
+
+      /* fall through */
+
+      case NLA_STRING:
+        if (attrlen < 1)
+          {
+            return -ERANGE;
+          }
+
+        if (pt->len)
+          {
+            FAR char *buf = nla_data(nla);
+
+            if (buf[attrlen - 1] == '\0')
+              attrlen--;
+
+            if (attrlen > pt->len)
+              return -ERANGE;
+          }
+        break;
+
+      case NLA_BINARY:
+        if (pt->len && attrlen > pt->len)
+          {
+            return -ERANGE;
+          }
+        break;
+
+      case NLA_NESTED_COMPAT:
+        if (attrlen < pt->len)
+          {
+            return -ERANGE;
+          }
+
+        if (attrlen < NLA_ALIGN(pt->len))
+          {
+            break;
+          }
+
+        if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN)
+          {
+            return -ERANGE;
+          }
+
+        nla = nla_data(nla) + NLA_ALIGN(pt->len);
+        if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla))
+          {
+            return -ERANGE;
+          }
+        break;
+
+      case NLA_NESTED:
+        /* a nested attributes is allowed to be empty; if its not,
+         * it must have a size of at least NLA_HDRLEN.
+         */
+
+        if (attrlen == 0)
+          {
+            break;
+          }
+
+      default:
+        if (pt->len)
+          {
+            minlen = pt->len;
+          }
+        else if (pt->type != NLA_UNSPEC)
+          {
+            minlen = g_nla_attr_minlen[pt->type];
+          }
+
+        if (attrlen < minlen)
+          {
+            return -ERANGE;
+          }
+    }
+
+  return 0;
+}
+#else
+#define validate_nla(nla, maxtype, policy) 0

Review Comment:
   Thanks for your comments.



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