/* * net/sched/em_nbyte.c N-Byte 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/sched.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[0]; }; static int em_nbyte_change(struct tcf_proto *tp, 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) kmalloc(em->datalen, GFP_KERNEL); if (em->data == 0UL) return -ENOBUFS; memcpy((void *) em->data, data, em->datalen); 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->hdr.off, 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);