linux/net/ife/ife.c
Yotam Gigi 1ce8460496 net: Introduce ife encapsulation module
This module is responsible for the ife encapsulation protocol
encode/decode logics. That module can:
 - ife_encode: encode skb and reserve space for the ife meta header
 - ife_decode: decode skb and extract the meta header size
 - ife_tlv_meta_encode - encodes one tlv entry into the reserved ife
   header space.
 - ife_tlv_meta_decode - decodes one tlv entry from the packet
 - ife_tlv_meta_next - advance to the next tlv

Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-03 15:16:45 -05:00

142 lines
3.6 KiB
C

/*
* 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;
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;
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;
};
/* Caller takes care of presenting data in network order
*/
void *ife_tlv_meta_decode(void *skbdata, u16 *attrtype, u16 *dlen, u16 *totlen)
{
struct meta_tlvhdr *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 <yotamg@mellanox.com>");
MODULE_DESCRIPTION("Inter-FE LFB action");
MODULE_LICENSE("GPL");