qemu/include/net/eth.h
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   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
  36struct eth_header {
  37    uint8_t  h_dest[ETH_ALEN];   /* destination eth addr */
  38    uint8_t  h_source[ETH_ALEN]; /* source ether addr    */
  39    uint16_t h_proto;            /* packet type ID field */
  40};
  41
  42struct vlan_header {
  43    uint16_t  h_tci;     /* priority and VLAN ID  */
  44    uint16_t  h_proto;   /* encapsulated protocol */
  45};
  46
  47struct ip_header {
  48    uint8_t  ip_ver_len;     /* version and header length */
  49    uint8_t  ip_tos;         /* type of service */
  50    uint16_t ip_len;         /* total length */
  51    uint16_t ip_id;          /* identification */
  52    uint16_t ip_off;         /* fragment offset field */
  53    uint8_t  ip_ttl;         /* time to live */
  54    uint8_t  ip_p;           /* protocol */
  55    uint16_t ip_sum;         /* checksum */
  56    uint32_t ip_src, ip_dst; /* source and destination address */
  57};
  58
  59typedef struct tcp_header {
  60    uint16_t th_sport;          /* source port */
  61    uint16_t th_dport;          /* destination port */
  62    uint32_t th_seq;            /* sequence number */
  63    uint32_t th_ack;            /* acknowledgment number */
  64    uint16_t th_offset_flags;   /* data offset, reserved 6 bits, */
  65                                /* TCP protocol flags */
  66    uint16_t th_win;            /* window */
  67    uint16_t th_sum;            /* checksum */
  68    uint16_t th_urp;            /* urgent pointer */
  69} tcp_header;
  70
  71typedef struct udp_header {
  72    uint16_t uh_sport; /* source port */
  73    uint16_t uh_dport; /* destination port */
  74    uint16_t uh_ulen;  /* udp length */
  75    uint16_t uh_sum;   /* udp checksum */
  76} udp_header;
  77
  78typedef struct ip_pseudo_header {
  79    uint32_t ip_src;
  80    uint32_t ip_dst;
  81    uint8_t  zeros;
  82    uint8_t  ip_proto;
  83    uint16_t ip_payload;
  84} ip_pseudo_header;
  85
  86/* IPv6 address */
  87struct in6_addr {
  88    union {
  89        uint8_t __u6_addr8[16];
  90    } __in6_u;
  91};
  92
  93struct ip6_header {
  94    union {
  95        struct ip6_hdrctl {
  96            uint32_t ip6_un1_flow; /* 4 bits version, 8 bits TC,
  97                                      20 bits flow-ID */
  98            uint16_t ip6_un1_plen; /* payload length */
  99            uint8_t  ip6_un1_nxt;  /* next header */
 100            uint8_t  ip6_un1_hlim; /* hop limit */
 101        } ip6_un1;
 102        uint8_t ip6_un2_vfc;       /* 4 bits version, top 4 bits tclass */
 103        struct ip6_ecn_access {
 104            uint8_t  ip6_un3_vfc;  /* 4 bits version, top 4 bits tclass */
 105            uint8_t  ip6_un3_ecn;  /* 2 bits ECN, top 6 bits payload length */
 106        } ip6_un3;
 107    } ip6_ctlun;
 108    struct in6_addr ip6_src;     /* source address */
 109    struct in6_addr ip6_dst;     /* destination address */
 110};
 111
 112struct ip6_ext_hdr {
 113    uint8_t        ip6r_nxt;   /* next header */
 114    uint8_t        ip6r_len;   /* length in units of 8 octets */
 115};
 116
 117struct udp_hdr {
 118  uint16_t uh_sport;           /* source port */
 119  uint16_t uh_dport;           /* destination port */
 120  uint16_t uh_ulen;            /* udp length */
 121  uint16_t uh_sum;             /* udp checksum */
 122};
 123
 124struct tcp_hdr {
 125    u_short     th_sport;   /* source port */
 126    u_short     th_dport;   /* destination port */
 127    uint32_t    th_seq;     /* sequence number */
 128    uint32_t    th_ack;     /* acknowledgment number */
 129#ifdef HOST_WORDS_BIGENDIAN
 130    u_char  th_off : 4,     /* data offset */
 131        th_x2:4;            /* (unused) */
 132#else
 133    u_char  th_x2 : 4,      /* (unused) */
 134        th_off:4;           /* data offset */
 135#endif
 136
 137#define TH_ELN  0x1 /* explicit loss notification */
 138#define TH_ECN  0x2 /* explicit congestion notification */
 139#define TH_FS   0x4 /* fast start */
 140
 141    u_char  th_flags;
 142#define TH_FIN  0x01
 143#define TH_SYN  0x02
 144#define TH_RST  0x04
 145#define TH_PUSH 0x08
 146#define TH_ACK  0x10
 147#define TH_URG  0x20
 148    u_short th_win;      /* window */
 149    u_short th_sum;      /* checksum */
 150    u_short th_urp;      /* urgent pointer */
 151};
 152
 153#define ip6_nxt      ip6_ctlun.ip6_un1.ip6_un1_nxt
 154#define ip6_ecn_acc  ip6_ctlun.ip6_un3.ip6_un3_ecn
 155
 156#define PKT_GET_ETH_HDR(p)        \
 157    ((struct eth_header *)(p))
 158#define PKT_GET_VLAN_HDR(p)       \
 159    ((struct vlan_header *) (((uint8_t *)(p)) + sizeof(struct eth_header)))
 160#define PKT_GET_DVLAN_HDR(p)       \
 161    (PKT_GET_VLAN_HDR(p) + 1)
 162#define PKT_GET_IP_HDR(p)         \
 163    ((struct ip_header *)(((uint8_t *)(p)) + eth_get_l2_hdr_length(p)))
 164#define IP_HDR_GET_LEN(p)         \
 165    ((((struct ip_header *)p)->ip_ver_len & 0x0F) << 2)
 166#define PKT_GET_IP_HDR_LEN(p)     \
 167    (IP_HDR_GET_LEN(PKT_GET_IP_HDR(p)))
 168#define PKT_GET_IP6_HDR(p)        \
 169    ((struct ip6_header *) (((uint8_t *)(p)) + eth_get_l2_hdr_length(p)))
 170#define IP_HEADER_VERSION(ip)     \
 171    ((ip->ip_ver_len >> 4)&0xf)
 172
 173#define ETH_P_IP                  (0x0800)
 174#define ETH_P_IPV6                (0x86dd)
 175#define ETH_P_VLAN                (0x8100)
 176#define ETH_P_DVLAN               (0x88a8)
 177#define VLAN_VID_MASK             0x0fff
 178#define IP_HEADER_VERSION_4       (4)
 179#define IP_HEADER_VERSION_6       (6)
 180#define IP_PROTO_TCP              (6)
 181#define IP_PROTO_UDP              (17)
 182#define IPTOS_ECN_MASK            0x03
 183#define IPTOS_ECN(x)              ((x) & IPTOS_ECN_MASK)
 184#define IPTOS_ECN_CE              0x03
 185#define IP6_ECN_MASK              0xC0
 186#define IP6_ECN(x)                ((x) & IP6_ECN_MASK)
 187#define IP6_ECN_CE                0xC0
 188#define IP4_DONT_FRAGMENT_FLAG    (1 << 14)
 189
 190#define IS_SPECIAL_VLAN_ID(x)     \
 191    (((x) == 0) || ((x) == 0xFFF))
 192
 193#define ETH_MAX_L2_HDR_LEN  \
 194    (sizeof(struct eth_header) + 2 * sizeof(struct vlan_header))
 195
 196#define ETH_MAX_IP4_HDR_LEN   (60)
 197#define ETH_MAX_IP_DGRAM_LEN  (0xFFFF)
 198
 199#define IP_FRAG_UNIT_SIZE     (8)
 200#define IP_FRAG_ALIGN_SIZE(x) ((x) & ~0x7)
 201#define IP_RF                 0x8000           /* reserved fragment flag */
 202#define IP_DF                 0x4000           /* don't fragment flag */
 203#define IP_MF                 0x2000           /* more fragments flag */
 204#define IP_OFFMASK            0x1fff           /* mask for fragmenting bits */
 205
 206#define IP6_EXT_GRANULARITY   (8)  /* Size granularity for
 207                                      IPv6 extension headers */
 208
 209/* IP6 extension header types */
 210#define IP6_HOP_BY_HOP        (0)
 211#define IP6_ROUTING           (43)
 212#define IP6_FRAGMENT          (44)
 213#define IP6_ESP               (50)
 214#define IP6_AUTHENTICATION    (51)
 215#define IP6_NONE              (59)
 216#define IP6_DESTINATON        (60)
 217#define IP6_MOBILITY          (135)
 218
 219static inline int is_multicast_ether_addr(const uint8_t *addr)
 220{
 221    return 0x01 & addr[0];
 222}
 223
 224static inline int is_broadcast_ether_addr(const uint8_t *addr)
 225{
 226    return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
 227}
 228
 229static inline int is_unicast_ether_addr(const uint8_t *addr)
 230{
 231    return !is_multicast_ether_addr(addr);
 232}
 233
 234typedef enum {
 235    ETH_PKT_UCAST = 0xAABBCC00,
 236    ETH_PKT_BCAST,
 237    ETH_PKT_MCAST
 238} eth_pkt_types_e;
 239
 240static inline eth_pkt_types_e
 241get_eth_packet_type(const struct eth_header *ehdr)
 242{
 243    if (is_broadcast_ether_addr(ehdr->h_dest)) {
 244        return ETH_PKT_BCAST;
 245    } else if (is_multicast_ether_addr(ehdr->h_dest)) {
 246        return ETH_PKT_MCAST;
 247    } else { /* unicast */
 248        return ETH_PKT_UCAST;
 249    }
 250}
 251
 252static inline uint32_t
 253eth_get_l2_hdr_length(const void *p)
 254{
 255    uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 256    struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 257    switch (proto) {
 258    case ETH_P_VLAN:
 259        return sizeof(struct eth_header) + sizeof(struct vlan_header);
 260    case ETH_P_DVLAN:
 261        if (hvlan->h_proto == ETH_P_VLAN) {
 262            return sizeof(struct eth_header) + 2 * sizeof(struct vlan_header);
 263        } else {
 264            return sizeof(struct eth_header) + sizeof(struct vlan_header);
 265        }
 266    default:
 267        return sizeof(struct eth_header);
 268    }
 269}
 270
 271static inline uint16_t
 272eth_get_pkt_tci(const void *p)
 273{
 274    uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 275    struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 276    switch (proto) {
 277    case ETH_P_VLAN:
 278    case ETH_P_DVLAN:
 279        return be16_to_cpu(hvlan->h_tci);
 280    default:
 281        return 0;
 282    }
 283}
 284
 285static inline bool
 286eth_strip_vlan(const void *p, uint8_t *new_ehdr_buf,
 287               uint16_t *payload_offset, uint16_t *tci)
 288{
 289    uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 290    struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 291    struct eth_header *new_ehdr = (struct eth_header *) new_ehdr_buf;
 292
 293    switch (proto) {
 294    case ETH_P_VLAN:
 295    case ETH_P_DVLAN:
 296        memcpy(new_ehdr->h_source, PKT_GET_ETH_HDR(p)->h_source, ETH_ALEN);
 297        memcpy(new_ehdr->h_dest, PKT_GET_ETH_HDR(p)->h_dest, ETH_ALEN);
 298        new_ehdr->h_proto = hvlan->h_proto;
 299        *tci = be16_to_cpu(hvlan->h_tci);
 300        *payload_offset =
 301            sizeof(struct eth_header) + sizeof(struct vlan_header);
 302        if (be16_to_cpu(new_ehdr->h_proto) == ETH_P_VLAN) {
 303            memcpy(PKT_GET_VLAN_HDR(new_ehdr),
 304                   PKT_GET_DVLAN_HDR(p),
 305                   sizeof(struct vlan_header));
 306            *payload_offset += sizeof(struct vlan_header);
 307        }
 308        return true;
 309    default:
 310        return false;
 311    }
 312}
 313
 314static inline uint16_t
 315eth_get_l3_proto(const void *l2hdr, size_t l2hdr_len)
 316{
 317    uint8_t *proto_ptr = (uint8_t *) l2hdr + l2hdr_len - sizeof(uint16_t);
 318    return be16_to_cpup((uint16_t *)proto_ptr);
 319}
 320
 321void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
 322    bool *is_new);
 323
 324uint8_t eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto);
 325
 326void eth_get_protocols(const uint8_t *headers,
 327                       uint32_t hdr_length,
 328                       bool *isip4, bool *isip6,
 329                       bool *isudp, bool *istcp);
 330
 331void eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
 332                                 void *l3hdr, size_t l3hdr_len,
 333                                 size_t l3payload_len,
 334                                 size_t frag_offset, bool more_frags);
 335
 336void
 337eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len);
 338
 339uint32_t
 340eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl);
 341
 342bool
 343eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
 344                   size_t ip6hdr_off, uint8_t *l4proto,
 345                   size_t *full_hdr_len);
 346
 347#endif
 348