1 /* 2 * net/ife/ife.c - Inter-FE protocol based on ForCES WG InterFE LFB 3 * Copyright (c) 2015 Jamal Hadi Salim <jhs@mojatatu.com> 4 * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com> 5 * 6 * Refer to: draft-ietf-forces-interfelfb-03 and netdev01 paper: 7 * "Distributing Linux Traffic Control Classifier-Action Subsystem" 8 * Authors: Jamal Hadi Salim and Damascene M. Joachimpillai 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation. 13 */ 14 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/module.h> 22 #include <linux/init.h> 23 #include <net/net_namespace.h> 24 #include <net/netlink.h> 25 #include <net/pkt_sched.h> 26 #include <linux/etherdevice.h> 27 #include <net/ife.h> 28 29 struct ifeheadr { 30 __be16 metalen; 31 u8 tlv_data[]; 32 }; 33 34 void *ife_encode(struct sk_buff *skb, u16 metalen) 35 { 36 /* OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA 37 * where ORIGDATA = original ethernet header ... 38 */ 39 int hdrm = metalen + IFE_METAHDRLEN; 40 int total_push = hdrm + skb->dev->hard_header_len; 41 struct ifeheadr *ifehdr; 42 struct ethhdr *iethh; /* inner ether header */ 43 int skboff = 0; 44 int err; 45 46 err = skb_cow_head(skb, total_push); 47 if (unlikely(err)) 48 return NULL; 49 50 iethh = (struct ethhdr *) skb->data; 51 52 __skb_push(skb, total_push); 53 memcpy(skb->data, iethh, skb->dev->hard_header_len); 54 skb_reset_mac_header(skb); 55 skboff += skb->dev->hard_header_len; 56 57 /* total metadata length */ 58 ifehdr = (struct ifeheadr *) (skb->data + skboff); 59 metalen += IFE_METAHDRLEN; 60 ifehdr->metalen = htons(metalen); 61 62 return ifehdr->tlv_data; 63 } 64 EXPORT_SYMBOL_GPL(ife_encode); 65 66 void *ife_decode(struct sk_buff *skb, u16 *metalen) 67 { 68 struct ifeheadr *ifehdr; 69 int total_pull; 70 u16 ifehdrln; 71 72 ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len); 73 ifehdrln = ntohs(ifehdr->metalen); 74 total_pull = skb->dev->hard_header_len + ifehdrln; 75 76 if (unlikely(ifehdrln < 2)) 77 return NULL; 78 79 if (unlikely(!pskb_may_pull(skb, total_pull))) 80 return NULL; 81 82 skb_set_mac_header(skb, total_pull); 83 __skb_pull(skb, total_pull); 84 *metalen = ifehdrln - IFE_METAHDRLEN; 85 86 return &ifehdr->tlv_data; 87 } 88 EXPORT_SYMBOL_GPL(ife_decode); 89 90 struct meta_tlvhdr { 91 __be16 type; 92 __be16 len; 93 }; 94 95 /* Caller takes care of presenting data in network order 96 */ 97 void *ife_tlv_meta_decode(void *skbdata, u16 *attrtype, u16 *dlen, u16 *totlen) 98 { 99 struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata; 100 101 *dlen = ntohs(tlv->len) - NLA_HDRLEN; 102 *attrtype = ntohs(tlv->type); 103 104 if (totlen) 105 *totlen = nla_total_size(*dlen); 106 107 return skbdata + sizeof(struct meta_tlvhdr); 108 } 109 EXPORT_SYMBOL_GPL(ife_tlv_meta_decode); 110 111 void *ife_tlv_meta_next(void *skbdata) 112 { 113 struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata; 114 u16 tlvlen = ntohs(tlv->len); 115 116 tlvlen = NLA_ALIGN(tlvlen); 117 118 return skbdata + tlvlen; 119 } 120 EXPORT_SYMBOL_GPL(ife_tlv_meta_next); 121 122 /* Caller takes care of presenting data in network order 123 */ 124 int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval) 125 { 126 __be32 *tlv = (__be32 *) (skbdata); 127 u16 totlen = nla_total_size(dlen); /*alignment + hdr */ 128 char *dptr = (char *) tlv + NLA_HDRLEN; 129 u32 htlv = attrtype << 16 | (dlen + NLA_HDRLEN); 130 131 *tlv = htonl(htlv); 132 memset(dptr, 0, totlen - NLA_HDRLEN); 133 memcpy(dptr, dval, dlen); 134 135 return totlen; 136 } 137 EXPORT_SYMBOL_GPL(ife_tlv_meta_encode); 138 139 MODULE_AUTHOR("Jamal Hadi Salim <jhs@mojatatu.com>"); 140 MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>"); 141 MODULE_DESCRIPTION("Inter-FE LFB action"); 142 MODULE_LICENSE("GPL"); 143