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/*
* net/ife/ife.c - Inter-FE protocol based on ForCES WG InterFE LFB
* Copyright (c) 2015 Jamal Hadi Salim <jhs@mojatatu.com>
* Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
*
* Refer to: draft-ietf-forces-interfelfb-03 and netdev01 paper:
* "Distributing Linux Traffic Control Classifier-Action Subsystem"
* Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
*
* 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.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/etherdevice.h>
#include <net/ife.h>
struct ifeheadr {
__be16 metalen;
u8 tlv_data[];
};
void *ife_encode(struct sk_buff *skb, u16 metalen)
{
/* OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
* where ORIGDATA = original ethernet header ...
*/
int hdrm = metalen + IFE_METAHDRLEN;
int total_push = hdrm + skb->dev->hard_header_len;
struct ifeheadr *ifehdr;
struct ethhdr *iethh; /* inner ether header */
int skboff = 0;
int err;
err = skb_cow_head(skb, total_push);
if (unlikely(err))
return NULL;
iethh = (struct ethhdr *) skb->data;
__skb_push(skb, total_push);
memcpy(skb->data, iethh, skb->dev->hard_header_len);
skb_reset_mac_header(skb);
skboff += skb->dev->hard_header_len;
/* total metadata length */
ifehdr = (struct ifeheadr *) (skb->data + skboff);
metalen += IFE_METAHDRLEN;
ifehdr->metalen = htons(metalen);
return ifehdr->tlv_data;
}
EXPORT_SYMBOL_GPL(ife_encode);
void *ife_decode(struct sk_buff *skb, u16 *metalen)
{
struct ifeheadr *ifehdr;
int total_pull;
u16 ifehdrln;
if (!pskb_may_pull(skb, skb->dev->hard_header_len + IFE_METAHDRLEN))
return NULL;
ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len);
ifehdrln = ntohs(ifehdr->metalen);
total_pull = skb->dev->hard_header_len + ifehdrln;
if (unlikely(ifehdrln < 2))
return NULL;
if (unlikely(!pskb_may_pull(skb, total_pull)))
return NULL;
ifehdr = (struct ifeheadr *)(skb->data + skb->dev->hard_header_len);
skb_set_mac_header(skb, total_pull);
__skb_pull(skb, total_pull);
*metalen = ifehdrln - IFE_METAHDRLEN;
return &ifehdr->tlv_data;
}
EXPORT_SYMBOL_GPL(ife_decode);
struct meta_tlvhdr {
__be16 type;
__be16 len;
};
static bool __ife_tlv_meta_valid(const unsigned char *skbdata,
const unsigned char *ifehdr_end)
{
const struct meta_tlvhdr *tlv;
u16 tlvlen;
if (unlikely(skbdata + sizeof(*tlv) > ifehdr_end))
return false;
tlv = (const struct meta_tlvhdr *)skbdata;
tlvlen = ntohs(tlv->len);
/* tlv length field is inc header, check on minimum */
if (tlvlen < NLA_HDRLEN)
return false;
/* overflow by NLA_ALIGN check */
if (NLA_ALIGN(tlvlen) < tlvlen)
return false;
if (unlikely(skbdata + NLA_ALIGN(tlvlen) > ifehdr_end))
return false;
return true;
}
/* Caller takes care of presenting data in network order
*/
void *ife_tlv_meta_decode(void *skbdata, const void *ifehdr_end, u16 *attrtype,
u16 *dlen, u16 *totlen)
{
struct meta_tlvhdr *tlv;
if (!__ife_tlv_meta_valid(skbdata, ifehdr_end))
return NULL;
tlv = (struct meta_tlvhdr *)skbdata;
*dlen = ntohs(tlv->len) - NLA_HDRLEN;
*attrtype = ntohs(tlv->type);
if (totlen)
*totlen = nla_total_size(*dlen);
return skbdata + sizeof(struct meta_tlvhdr);
}
EXPORT_SYMBOL_GPL(ife_tlv_meta_decode);
void *ife_tlv_meta_next(void *skbdata)
{
struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata;
u16 tlvlen = ntohs(tlv->len);
tlvlen = NLA_ALIGN(tlvlen);
return skbdata + tlvlen;
}
EXPORT_SYMBOL_GPL(ife_tlv_meta_next);
/* Caller takes care of presenting data in network order
*/
int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval)
{
__be32 *tlv = (__be32 *) (skbdata);
u16 totlen = nla_total_size(dlen); /*alignment + hdr */
char *dptr = (char *) tlv + NLA_HDRLEN;
u32 htlv = attrtype << 16 | (dlen + NLA_HDRLEN);
*tlv = htonl(htlv);
memset(dptr, 0, totlen - NLA_HDRLEN);
memcpy(dptr, dval, dlen);
return totlen;
}
EXPORT_SYMBOL_GPL(ife_tlv_meta_encode);
MODULE_AUTHOR("Jamal Hadi Salim <jhs@mojatatu.com>");
MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
MODULE_DESCRIPTION("Inter-FE LFB action");
MODULE_LICENSE("GPL");
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