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 ife_encode(struct sk_buff * skb,u16 metalen)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 ife_decode(struct sk_buff * skb,u16 * metalen)66 void *ife_decode(struct sk_buff *skb, u16 *metalen) 67 { 68 struct ifeheadr *ifehdr; 69 int total_pull; 70 u16 ifehdrln; 71 72 if (!pskb_may_pull(skb, skb->dev->hard_header_len + IFE_METAHDRLEN)) 73 return NULL; 74 75 ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len); 76 ifehdrln = ntohs(ifehdr->metalen); 77 total_pull = skb->dev->hard_header_len + ifehdrln; 78 79 if (unlikely(ifehdrln < 2)) 80 return NULL; 81 82 if (unlikely(!pskb_may_pull(skb, total_pull))) 83 return NULL; 84 85 skb_set_mac_header(skb, total_pull); 86 __skb_pull(skb, total_pull); 87 *metalen = ifehdrln - IFE_METAHDRLEN; 88 89 return &ifehdr->tlv_data; 90 } 91 EXPORT_SYMBOL_GPL(ife_decode); 92 93 struct meta_tlvhdr { 94 __be16 type; 95 __be16 len; 96 }; 97 __ife_tlv_meta_valid(const unsigned char * skbdata,const unsigned char * ifehdr_end)98 static bool __ife_tlv_meta_valid(const unsigned char *skbdata, 99 const unsigned char *ifehdr_end) 100 { 101 const struct meta_tlvhdr *tlv; 102 u16 tlvlen; 103 104 if (unlikely(skbdata + sizeof(*tlv) > ifehdr_end)) 105 return false; 106 107 tlv = (const struct meta_tlvhdr *)skbdata; 108 tlvlen = ntohs(tlv->len); 109 110 /* tlv length field is inc header, check on minimum */ 111 if (tlvlen < NLA_HDRLEN) 112 return false; 113 114 /* overflow by NLA_ALIGN check */ 115 if (NLA_ALIGN(tlvlen) < tlvlen) 116 return false; 117 118 if (unlikely(skbdata + NLA_ALIGN(tlvlen) > ifehdr_end)) 119 return false; 120 121 return true; 122 } 123 124 /* Caller takes care of presenting data in network order 125 */ ife_tlv_meta_decode(void * skbdata,const void * ifehdr_end,u16 * attrtype,u16 * dlen,u16 * totlen)126 void *ife_tlv_meta_decode(void *skbdata, const void *ifehdr_end, u16 *attrtype, 127 u16 *dlen, u16 *totlen) 128 { 129 struct meta_tlvhdr *tlv; 130 131 if (!__ife_tlv_meta_valid(skbdata, ifehdr_end)) 132 return NULL; 133 134 tlv = (struct meta_tlvhdr *)skbdata; 135 *dlen = ntohs(tlv->len) - NLA_HDRLEN; 136 *attrtype = ntohs(tlv->type); 137 138 if (totlen) 139 *totlen = nla_total_size(*dlen); 140 141 return skbdata + sizeof(struct meta_tlvhdr); 142 } 143 EXPORT_SYMBOL_GPL(ife_tlv_meta_decode); 144 ife_tlv_meta_next(void * skbdata)145 void *ife_tlv_meta_next(void *skbdata) 146 { 147 struct meta_tlvhdr *tlv = (struct meta_tlvhdr *) skbdata; 148 u16 tlvlen = ntohs(tlv->len); 149 150 tlvlen = NLA_ALIGN(tlvlen); 151 152 return skbdata + tlvlen; 153 } 154 EXPORT_SYMBOL_GPL(ife_tlv_meta_next); 155 156 /* Caller takes care of presenting data in network order 157 */ ife_tlv_meta_encode(void * skbdata,u16 attrtype,u16 dlen,const void * dval)158 int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval) 159 { 160 __be32 *tlv = (__be32 *) (skbdata); 161 u16 totlen = nla_total_size(dlen); /*alignment + hdr */ 162 char *dptr = (char *) tlv + NLA_HDRLEN; 163 u32 htlv = attrtype << 16 | (dlen + NLA_HDRLEN); 164 165 *tlv = htonl(htlv); 166 memset(dptr, 0, totlen - NLA_HDRLEN); 167 memcpy(dptr, dval, dlen); 168 169 return totlen; 170 } 171 EXPORT_SYMBOL_GPL(ife_tlv_meta_encode); 172 173 MODULE_AUTHOR("Jamal Hadi Salim <jhs@mojatatu.com>"); 174 MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>"); 175 MODULE_DESCRIPTION("Inter-FE LFB action"); 176 MODULE_LICENSE("GPL"); 177