include/net/eth.h

   1 /*
   2  * QEMU network structures definitions and helper functions
   3  *
   4  * Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com)
   5  *
   6  * Developed by Daynix Computing LTD (http://www.daynix.com)
   7  *
   8  * Portions developed by Free Software Foundation, Inc
   9  * Copyright (C) 1991-1997, 2001, 2003, 2006 Free Software Foundation, Inc.
  10  * See netinet/ip6.h and netinet/in.h (GNU C Library)
  11  *
  12  * Portions developed by Igor Kovalenko
  13  * Copyright (c) 2006 Igor Kovalenko
  14  * See hw/rtl8139.c (QEMU)
  15  *
  16  * Authors:
  17  * Dmitry Fleytman <dmitry@daynix.com>
  18  * Tamir Shomer <tamirs@daynix.com>
  19  * Yan Vugenfirer <yan@daynix.com>
  20  *
  21  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  22  * See the COPYING file in the top-level directory.
  23  *
  24  */
  25
  26 #ifndef QEMU_ETH_H
  27 #define QEMU_ETH_H
  28
  29 #include <sys/types.h>
  30 #include <string.h>
  31 #include "qemu/bswap.h"
  32 #include "qemu/iov.h"
  33
  34 #define ETH_ALEN 6
  35 #define ETH_HLEN 14
  36
  37 struct eth_header {
  38     uint8_t  h_dest[ETH_ALEN];   /* destination eth addr */
  39     uint8_t  h_source[ETH_ALEN]; /* source ether addr    */
  40     uint16_t h_proto;            /* packet type ID field */
  41 };
  42
  43 struct vlan_header {
  44     uint16_t  h_tci;     /* priority and VLAN ID  */
  45     uint16_t  h_proto;   /* encapsulated protocol */
  46 };
  47
  48 struct ip_header {
  49     uint8_t  ip_ver_len;     /* version and header length */
  50     uint8_t  ip_tos;         /* type of service */
  51     uint16_t ip_len;         /* total length */
  52     uint16_t ip_id;          /* identification */
  53     uint16_t ip_off;         /* fragment offset field */
  54     uint8_t  ip_ttl;         /* time to live */
  55     uint8_t  ip_p;           /* protocol */
  56     uint16_t ip_sum;         /* checksum */
  57     uint32_t ip_src, ip_dst; /* source and destination address */
  58 };
  59
  60 typedef struct tcp_header {
  61     uint16_t th_sport;          /* source port */
  62     uint16_t th_dport;          /* destination port */
  63     uint32_t th_seq;            /* sequence number */
  64     uint32_t th_ack;            /* acknowledgment number */
  65     uint16_t th_offset_flags;   /* data offset, reserved 6 bits, */
  66                                 /* TCP protocol flags */
  67     uint16_t th_win;            /* window */
  68     uint16_t th_sum;            /* checksum */
  69     uint16_t th_urp;            /* urgent pointer */
  70 } tcp_header;
  71
  72 typedef struct udp_header {
  73     uint16_t uh_sport; /* source port */
  74     uint16_t uh_dport; /* destination port */
  75     uint16_t uh_ulen;  /* udp length */
  76     uint16_t uh_sum;   /* udp checksum */
  77 } udp_header;
  78
  79 typedef struct ip_pseudo_header {
  80     uint32_t ip_src;
  81     uint32_t ip_dst;
  82     uint8_t  zeros;
  83     uint8_t  ip_proto;
  84     uint16_t ip_payload;
  85 } ip_pseudo_header;
  86
  87 /* IPv6 address */
  88 struct in6_address {
  89     union {
  90         uint8_t __u6_addr8[16];
  91     } __in6_u;
  92 };
  93
  94 struct ip6_header {
  95     union {
  96         struct ip6_hdrctl {
  97             uint32_t ip6_un1_flow; /* 4 bits version, 8 bits TC,
  98                                       20 bits flow-ID */
  99             uint16_t ip6_un1_plen; /* payload length */
 100             uint8_t  ip6_un1_nxt;  /* next header */
 101             uint8_t  ip6_un1_hlim; /* hop limit */
 102         } ip6_un1;
 103         uint8_t ip6_un2_vfc;       /* 4 bits version, top 4 bits tclass */
 104         struct ip6_ecn_access {
 105             uint8_t  ip6_un3_vfc;  /* 4 bits version, top 4 bits tclass */
 106             uint8_t  ip6_un3_ecn;  /* 2 bits ECN, top 6 bits payload length */
 107         } ip6_un3;
 108     } ip6_ctlun;
 109     struct in6_address ip6_src;    /* source address */
 110     struct in6_address ip6_dst;    /* destination address */
 111 };
 112
 113 struct ip6_ext_hdr {
 114     uint8_t        ip6r_nxt;   /* next header */
 115     uint8_t        ip6r_len;   /* length in units of 8 octets */
 116 };
 117
 118 struct udp_hdr {
 119   uint16_t uh_sport;           /* source port */
 120   uint16_t uh_dport;           /* destination port */
 121   uint16_t uh_ulen;            /* udp length */
 122   uint16_t uh_sum;             /* udp checksum */
 123 };
 124
 125 struct tcp_hdr {
 126     u_short     th_sport;   /* source port */
 127     u_short     th_dport;   /* destination port */
 128     uint32_t    th_seq;     /* sequence number */
 129     uint32_t    th_ack;     /* acknowledgment number */
 130 #ifdef HOST_WORDS_BIGENDIAN
 131     u_char  th_off : 4,     /* data offset */
 132         th_x2:4;            /* (unused) */
 133 #else
 134     u_char  th_x2 : 4,      /* (unused) */
 135         th_off:4;           /* data offset */
 136 #endif
 137
 138 #define TH_ELN  0x1 /* explicit loss notification */
 139 #define TH_ECN  0x2 /* explicit congestion notification */
 140 #define TH_FS   0x4 /* fast start */
 141
 142     u_char  th_flags;
 143 #define TH_FIN  0x01
 144 #define TH_SYN  0x02
 145 #define TH_RST  0x04
 146 #define TH_PUSH 0x08
 147 #define TH_ACK  0x10
 148 #define TH_URG  0x20
 149     u_short th_win;      /* window */
 150     u_short th_sum;      /* checksum */
 151     u_short th_urp;      /* urgent pointer */
 152 };
 153
 154 #define ip6_nxt      ip6_ctlun.ip6_un1.ip6_un1_nxt
 155 #define ip6_ecn_acc  ip6_ctlun.ip6_un3.ip6_un3_ecn
 156
 157 #define PKT_GET_ETH_HDR(p)        \
 158     ((struct eth_header *)(p))
 159 #define PKT_GET_VLAN_HDR(p)       \
 160     ((struct vlan_header *) (((uint8_t *)(p)) + sizeof(struct eth_header)))
 161 #define PKT_GET_DVLAN_HDR(p)       \
 162     (PKT_GET_VLAN_HDR(p) + 1)
 163 #define PKT_GET_IP_HDR(p)         \
 164     ((struct ip_header *)(((uint8_t *)(p)) + eth_get_l2_hdr_length(p)))
 165 #define IP_HDR_GET_LEN(p)         \
 166     ((((struct ip_header *)p)->ip_ver_len & 0x0F) << 2)
 167 #define PKT_GET_IP_HDR_LEN(p)     \
 168     (IP_HDR_GET_LEN(PKT_GET_IP_HDR(p)))
 169 #define PKT_GET_IP6_HDR(p)        \
 170     ((struct ip6_header *) (((uint8_t *)(p)) + eth_get_l2_hdr_length(p)))
 171 #define IP_HEADER_VERSION(ip)     \
 172     ((ip->ip_ver_len >> 4)&0xf)
 173
 174 #define ETH_P_IP                  (0x0800)      /* Internet Protocol packet  */
 175 #define ETH_P_ARP                 (0x0806)      /* Address Resolution packet */
 176 #define ETH_P_IPV6                (0x86dd)
 177 #define ETH_P_VLAN                (0x8100)
 178 #define ETH_P_DVLAN               (0x88a8)
 179 #define VLAN_VID_MASK             0x0fff
 180 #define IP_HEADER_VERSION_4       (4)
 181 #define IP_HEADER_VERSION_6       (6)
 182 #define IP_PROTO_TCP              (6)
 183 #define IP_PROTO_UDP              (17)
 184 #define IPTOS_ECN_MASK            0x03
 185 #define IPTOS_ECN(x)              ((x) & IPTOS_ECN_MASK)
 186 #define IPTOS_ECN_CE              0x03
 187 #define IP6_ECN_MASK              0xC0
 188 #define IP6_ECN(x)                ((x) & IP6_ECN_MASK)
 189 #define IP6_ECN_CE                0xC0
 190 #define IP4_DONT_FRAGMENT_FLAG    (1 << 14)
 191
 192 #define IS_SPECIAL_VLAN_ID(x)     \
 193     (((x) == 0) || ((x) == 0xFFF))
 194
 195 #define ETH_MAX_L2_HDR_LEN  \
 196     (sizeof(struct eth_header) + 2 * sizeof(struct vlan_header))
 197
 198 #define ETH_MAX_IP4_HDR_LEN   (60)
 199 #define ETH_MAX_IP_DGRAM_LEN  (0xFFFF)
 200
 201 #define IP_FRAG_UNIT_SIZE     (8)
 202 #define IP_FRAG_ALIGN_SIZE(x) ((x) & ~0x7)
 203 #define IP_RF                 0x8000           /* reserved fragment flag */
 204 #define IP_DF                 0x4000           /* don't fragment flag */
 205 #define IP_MF                 0x2000           /* more fragments flag */
 206 #define IP_OFFMASK            0x1fff           /* mask for fragmenting bits */
 207
 208 #define IP6_EXT_GRANULARITY   (8)  /* Size granularity for
 209                                       IPv6 extension headers */
 210
 211 /* IP6 extension header types */
 212 #define IP6_HOP_BY_HOP        (0)
 213 #define IP6_ROUTING           (43)
 214 #define IP6_FRAGMENT          (44)
 215 #define IP6_ESP               (50)
 216 #define IP6_AUTHENTICATION    (51)
 217 #define IP6_NONE              (59)
 218 #define IP6_DESTINATON        (60)
 219 #define IP6_MOBILITY          (135)
 220
 221 static inline int is_multicast_ether_addr(const uint8_t *addr)
 222 {
 223     return 0x01 & addr[0];
 224 }
 225
 226 static inline int is_broadcast_ether_addr(const uint8_t *addr)
 227 {
 228     return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
 229 }
 230
 231 static inline int is_unicast_ether_addr(const uint8_t *addr)
 232 {
 233     return !is_multicast_ether_addr(addr);
 234 }
 235
 236 typedef enum {
 237     ETH_PKT_UCAST = 0xAABBCC00,
 238     ETH_PKT_BCAST,
 239     ETH_PKT_MCAST
 240 } eth_pkt_types_e;
 241
 242 static inline eth_pkt_types_e
 243 get_eth_packet_type(const struct eth_header *ehdr)
 244 {
 245     if (is_broadcast_ether_addr(ehdr->h_dest)) {
 246         return ETH_PKT_BCAST;
 247     } else if (is_multicast_ether_addr(ehdr->h_dest)) {
 248         return ETH_PKT_MCAST;
 249     } else { /* unicast */
 250         return ETH_PKT_UCAST;
 251     }
 252 }
 253
 254 static inline uint32_t
 255 eth_get_l2_hdr_length(const void *p)
 256 {
 257     uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 258     struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 259     switch (proto) {
 260     case ETH_P_VLAN:
 261         return sizeof(struct eth_header) + sizeof(struct vlan_header);
 262     case ETH_P_DVLAN:
 263         if (hvlan->h_proto == ETH_P_VLAN) {
 264             return sizeof(struct eth_header) + 2 * sizeof(struct vlan_header);
 265         } else {
 266             return sizeof(struct eth_header) + sizeof(struct vlan_header);
 267         }
 268     default:
 269         return sizeof(struct eth_header);
 270     }
 271 }
 272
 273 static inline uint16_t
 274 eth_get_pkt_tci(const void *p)
 275 {
 276     uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 277     struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 278     switch (proto) {
 279     case ETH_P_VLAN:
 280     case ETH_P_DVLAN:
 281         return be16_to_cpu(hvlan->h_tci);
 282     default:
 283         return 0;
 284     }
 285 }
 286
 287 static inline bool
 288 eth_strip_vlan(const void *p, uint8_t *new_ehdr_buf,
 289                uint16_t *payload_offset, uint16_t *tci)
 290 {
 291     uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 292     struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 293     struct eth_header *new_ehdr = (struct eth_header *) new_ehdr_buf;
 294
 295     switch (proto) {
 296     case ETH_P_VLAN:
 297     case ETH_P_DVLAN:
 298         memcpy(new_ehdr->h_source, PKT_GET_ETH_HDR(p)->h_source, ETH_ALEN);
 299         memcpy(new_ehdr->h_dest, PKT_GET_ETH_HDR(p)->h_dest, ETH_ALEN);
 300         new_ehdr->h_proto = hvlan->h_proto;
 301         *tci = be16_to_cpu(hvlan->h_tci);
 302         *payload_offset =
 303             sizeof(struct eth_header) + sizeof(struct vlan_header);
 304         if (be16_to_cpu(new_ehdr->h_proto) == ETH_P_VLAN) {
 305             memcpy(PKT_GET_VLAN_HDR(new_ehdr),
 306                    PKT_GET_DVLAN_HDR(p),
 307                    sizeof(struct vlan_header));
 308             *payload_offset += sizeof(struct vlan_header);
 309         }
 310         return true;
 311     default:
 312         return false;
 313     }
 314 }
 315
 316 static inline uint16_t
 317 eth_get_l3_proto(const void *l2hdr, size_t l2hdr_len)
 318 {
 319     uint8_t *proto_ptr = (uint8_t *) l2hdr + l2hdr_len - sizeof(uint16_t);
 320     return be16_to_cpup((uint16_t *)proto_ptr);
 321 }
 322
 323 void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
 324     bool *is_new);
 325
 326 uint8_t eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto);
 327
 328 void eth_get_protocols(const uint8_t *headers,
 329                        uint32_t hdr_length,
 330                        bool *isip4, bool *isip6,
 331                        bool *isudp, bool *istcp);
 332
 333 void eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
 334                                  void *l3hdr, size_t l3hdr_len,
 335                                  size_t l3payload_len,
 336                                  size_t frag_offset, bool more_frags);
 337
 338 void
 339 eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len);
 340
 341 uint32_t
 342 eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl);
 343
 344 bool
 345 eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
 346                    size_t ip6hdr_off, uint8_t *l4proto,
 347                    size_t *full_hdr_len);
 348
 349 #endif