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-rw-r--r--net/sched/em_nbyte.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/net/sched/em_nbyte.c b/net/sched/em_nbyte.c
new file mode 100644
index 000000000..a83b237cb
--- /dev/null
+++ b/net/sched/em_nbyte.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/em_nbyte.c N-Byte ematch
+ *
+ * Authors: Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/tc_ematch/tc_em_nbyte.h>
+#include <net/pkt_cls.h>
+
+struct nbyte_data {
+ struct tcf_em_nbyte hdr;
+ char pattern[];
+};
+
+static int em_nbyte_change(struct net *net, void *data, int data_len,
+ struct tcf_ematch *em)
+{
+ struct tcf_em_nbyte *nbyte = data;
+
+ if (data_len < sizeof(*nbyte) ||
+ data_len < (sizeof(*nbyte) + nbyte->len))
+ return -EINVAL;
+
+ em->datalen = sizeof(*nbyte) + nbyte->len;
+ em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
+ if (em->data == 0UL)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int em_nbyte_match(struct sk_buff *skb, struct tcf_ematch *em,
+ struct tcf_pkt_info *info)
+{
+ struct nbyte_data *nbyte = (struct nbyte_data *) em->data;
+ unsigned char *ptr = tcf_get_base_ptr(skb, nbyte->hdr.layer);
+
+ ptr += nbyte->hdr.off;
+
+ if (!tcf_valid_offset(skb, ptr, nbyte->hdr.len))
+ return 0;
+
+ return !memcmp(ptr, nbyte->pattern, nbyte->hdr.len);
+}
+
+static struct tcf_ematch_ops em_nbyte_ops = {
+ .kind = TCF_EM_NBYTE,
+ .change = em_nbyte_change,
+ .match = em_nbyte_match,
+ .owner = THIS_MODULE,
+ .link = LIST_HEAD_INIT(em_nbyte_ops.link)
+};
+
+static int __init init_em_nbyte(void)
+{
+ return tcf_em_register(&em_nbyte_ops);
+}
+
+static void __exit exit_em_nbyte(void)
+{
+ tcf_em_unregister(&em_nbyte_ops);
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_em_nbyte);
+module_exit(exit_em_nbyte);
+
+MODULE_ALIAS_TCF_EMATCH(TCF_EM_NBYTE);