This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / net / sched / em_cmp.c

diff --git a/net/sched/em_cmp.c b/net/sched/em_cmp.c
new file mode 100644 (file)
index 0000000..bf1f00f
--- /dev/null
+++ b/net/sched/em_cmp.c
@@ -0,0 +1,101 @@
+/*
+ * net/sched/em_cmp.c  Simple packet data comparison ematch
+ *
+ *             This program is free software; you can redistribute it and/or
+ *             modify it under the terms of the GNU General Public License
+ *             as published by the Free Software Foundation; either version
+ *             2 of the License, or (at your option) any later version.
+ *
+ * Authors:    Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/tc_ematch/tc_em_cmp.h>
+#include <net/pkt_cls.h>
+
+static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp)
+{
+       return unlikely(cmp->flags & TCF_EM_CMP_TRANS);
+}
+
+static int em_cmp_match(struct sk_buff *skb, struct tcf_ematch *em,
+                       struct tcf_pkt_info *info)
+{
+       struct tcf_em_cmp *cmp = (struct tcf_em_cmp *) em->data;
+       unsigned char *ptr = tcf_get_base_ptr(skb, cmp->layer) + cmp->off;
+       u32 val = 0;
+
+       if (!tcf_valid_offset(skb, ptr, cmp->align))
+               return 0;
+
+       switch (cmp->align) {
+               case TCF_EM_ALIGN_U8:
+                       val = *ptr;
+                       break;
+
+               case TCF_EM_ALIGN_U16:
+                       val = *ptr << 8;
+                       val |= *(ptr+1);
+
+                       if (cmp_needs_transformation(cmp))
+                               val = be16_to_cpu(val);
+                       break;
+
+               case TCF_EM_ALIGN_U32:
+                       /* Worth checking boundries? The branching seems
+                        * to get worse. Visit again. */
+                       val = *ptr << 24;
+                       val |= *(ptr+1) << 16;
+                       val |= *(ptr+2) << 8;
+                       val |= *(ptr+3);
+
+                       if (cmp_needs_transformation(cmp))
+                               val = be32_to_cpu(val);
+                       break;
+
+               default:
+                       return 0;
+       }
+
+       if (cmp->mask)
+               val &= cmp->mask;
+
+       switch (cmp->opnd) {
+               case TCF_EM_OPND_EQ:
+                       return val == cmp->val;
+               case TCF_EM_OPND_LT:
+                       return val < cmp->val;
+               case TCF_EM_OPND_GT:
+                       return val > cmp->val;
+       }
+
+       return 0;
+}
+
+static struct tcf_ematch_ops em_cmp_ops = {
+       .kind     = TCF_EM_CMP,
+       .datalen  = sizeof(struct tcf_em_cmp),
+       .match    = em_cmp_match,
+       .owner    = THIS_MODULE,
+       .link     = LIST_HEAD_INIT(em_cmp_ops.link)
+};
+
+static int __init init_em_cmp(void)
+{
+       return tcf_em_register(&em_cmp_ops);
+}
+
+static void __exit exit_em_cmp(void) 
+{
+       tcf_em_unregister(&em_cmp_ops);
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_em_cmp);
+module_exit(exit_em_cmp);
+