/* * 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; 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");