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Diffstat (limited to 'net/ife/ife.c')
| -rw-r--r-- | net/ife/ife.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/net/ife/ife.c b/net/ife/ife.c new file mode 100644 index 000000000..be05b690b --- /dev/null +++ b/net/ife/ife.c @@ -0,0 +1,177 @@ +/* + * 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"); |