datapath: Introduce more compat support for <net/netlink.h>.

With this commit, I have successfully built the datapath, without warnings,
on 2.6.{18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,36} on i386,
2.6.31 on x86-64, and the kernels included with XenServer 5.5.0 and (some
prerelease kernel for) XenServer 5.6.0.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/linux-2.6/compat-2.6/include/net/netlink.h b/datapath/linux-2.6/compat-2.6/include/net/netlink.h
index c6f5e04f5a1ef2af1c4e799d5198ed2277ea4e21..c11a170087f3283229c1e4affe4dfd5881d20dca 100644 (file)
--- a/datapath/linux-2.6/compat-2.6/include/net/netlink.h
+++ b/datapath/linux-2.6/compat-2.6/include/net/netlink.h
@@ -20,24 +20,66 @@ static inline int VERIFY_NUL_STRING(struct nlattr *attr)
 }
 #endif /* !HAVE_NLA_NUL_STRING */
 
-
 #ifndef NLA_PUT_BE16
 #define NLA_PUT_BE16(skb, attrtype, value) \
         NLA_PUT_TYPE(skb, __be16, attrtype, value)
 #endif  /* !NLA_PUT_BE16 */
 
-
 #ifndef HAVE_NLA_GET_BE16
 /**
  * nla_get_be16 - return payload of __be16 attribute
  * @nla: __be16 netlink attribute
  */
-static inline __be16 nla_get_be16(struct nlattr *nla)
+static inline __be16 nla_get_be16(const struct nlattr *nla)
 {
         return *(__be16 *) nla_data(nla);
 }
 #endif  /* !HAVE_NLA_GET_BE16 */
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
+/**
+ * nla_get_be32 - return payload of __be32 attribute
+ * @nla: __be32 netlink attribute
+ */
+static inline __be32 nla_get_be32(const struct nlattr *nla)
+{
+        return *(__be32 *) nla_data(nla);
+}
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,29)
+/* These functions' nlattr source arguments weren't "const" before 2.6.29, so
+ * cast their arguments to the non-"const" versions.  Using macros for this
+ * isn't exactly a brilliant idea, but it seems less error-prone than copying
+ * the definitions of all umpteen functions. */
+#define nla_get_u64(nla)   (nla_get_u64)  ((struct nlattr *) (nla))
+#define nla_get_u32(nla)   (nla_get_u32)  ((struct nlattr *) (nla))
+#define nla_get_u16(nla)   (nla_get_u16)  ((struct nlattr *) (nla))
+#define nla_get_u8(nla)    (nla_get_u8)   ((struct nlattr *) (nla))
+/* nla_get_be64 is handled separately below. */
+#define nla_get_be32(nla)  (nla_get_be32) ((struct nlattr *) (nla))
+#define nla_get_be16(nla)  (nla_get_be16) ((struct nlattr *) (nla))
+#define nla_get_be8(nla)   (nla_get_be8)  ((struct nlattr *) (nla))
+#define nla_get_flag(nla)  (nla_get_flag) ((struct nlattr *) (nla))
+#define nla_get_msecs(nla) (nla_get_msecs)((struct nlattr *) (nla))
+#define nla_memcpy(dst, src, count) \
+       (nla_memcpy)(dst, (struct nlattr *)(src), count)
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,34)
+/* This function was introduced in 2.6.31, but initially it performed an
+ * unaligned access, so we replace it up to 2.6.34 where it was fixed.  */
+#define nla_get_be64 rpl_nla_get_be64
+static inline __be64 nla_get_be64(const struct nlattr *nla)
+{
+        __be64 tmp;
+
+       /* The additional cast is necessary because  */
+        nla_memcpy(&tmp, (struct nlattr *) nla, sizeof(tmp));
+
+        return tmp;
+}
+#endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
 /**