X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnetlink.c;h=725bba02f203324e679be9c3fe01f638f7f72318;hb=bad68a9965215511b305c59d7f1830344ec2241f;hp=3ed2f53a9e8c6a2b14e59e3ee2e6b0f30f430df8;hpb=ee913f985d470515cc018e57ea56aac3f087702f;p=openvswitch

diff --git a/lib/netlink.c b/lib/netlink.c
index 3ed2f53a..725bba02 100644
--- a/lib/netlink.c
+++ b/lib/netlink.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -358,6 +358,14 @@ nl_msg_next(struct ofpbuf *buffer, struct ofpbuf *msg)
 
 /* Attributes. */
 
+/* Returns the bits of 'nla->nla_type' that are significant for determining its
+ * type. */
+int
+nl_attr_type(const struct nlattr *nla)
+{
+    return nla->nla_type & NLA_TYPE_MASK;
+}
+
 /* Returns the first byte in the payload of attribute 'nla'. */
 const void *
 nl_attr_get(const struct nlattr *nla)
@@ -539,12 +547,12 @@ nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset,
         if (aligned_len > (char*)tail - (char*)p) {
             VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" aligned data len (%zu) "
                         "> bytes left (%tu)",
-                        offset, nla->nla_type, aligned_len,
+                        offset, nl_attr_type(nla), aligned_len,
                         (char*)tail - (char*)p);
             return false;
         }
 
-        type = nla->nla_type;
+        type = nl_attr_type(nla);
         if (type < n_attrs && policy[type].type != NL_A_NO_ATTR) {
             const struct nl_policy *e = &policy[type];
             size_t min_len, max_len;
@@ -574,6 +582,9 @@ nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset,
                 assert(n_required > 0);
                 --n_required;
             }
+            if (attrs[type]) {
+                VLOG_DBG_RL(&rl, "%zu: duplicate attr %"PRIu16, offset, type);
+            }
             attrs[type] = nla;
         } else {
             /* Skip attribute type that we don't care about. */
@@ -600,3 +611,39 @@ nl_parse_nested(const struct nlattr *nla, const struct nl_policy policy[],
     nl_attr_get_nested(nla, &buf);
     return nl_policy_parse(&buf, 0, policy, attrs, n_attrs);
 }
+
+static const struct nlattr *
+nl_attr_find__(const struct nlattr *attrs, size_t size, uint16_t type)
+{
+    const struct nlattr *nla;
+    size_t left;
+
+    NL_ATTR_FOR_EACH (nla, left, attrs, size) {
+        if (nl_attr_type (nla) == type) {
+            return nla;
+        }
+    }
+    return NULL;
+}
+
+/* Returns the first Netlink attribute within 'buf' with the specified 'type',
+ * skipping a header of 'hdr_len' bytes at the beginning of 'buf'.
+ *
+ * This function does not validate the attribute's length. */
+const struct nlattr *
+nl_attr_find(const struct ofpbuf *buf, size_t hdr_len, uint16_t type)
+{
+    const uint8_t *start = (const uint8_t *) buf->data + hdr_len;
+    return nl_attr_find__((const struct nlattr *) start, buf->size - hdr_len,
+                          type);
+}
+
+/* Returns the first Netlink attribute within 'nla' with the specified
+ * 'type'.
+ *
+ * This function does not validate the attribute's length. */
+const struct nlattr *
+nl_attr_find_nested(const struct nlattr *nla, uint16_t type)
+{
+    return nl_attr_find__(nl_attr_get(nla), nl_attr_get_size(nla), type);
+}