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 "qemu/bswap.h"
  30 #include "qemu/iov.h"
  31
  32 #define ETH_ALEN 6
  33 #define ETH_HLEN 14
  34
  35 struct eth_header {
  36     uint8_t  h_dest[ETH_ALEN];   /* destination eth addr */
  37     uint8_t  h_source[ETH_ALEN]; /* source ether addr    */
  38     uint16_t h_proto;            /* packet type ID field */
  39 };
  40
  41 struct vlan_header {
  42     uint16_t  h_tci;     /* priority and VLAN ID  */
  43     uint16_t  h_proto;   /* encapsulated protocol */
  44 };
  45
  46 struct ip_header {
  47     uint8_t  ip_ver_len;     /* version and header length */
  48     uint8_t  ip_tos;         /* type of service */
  49     uint16_t ip_len;         /* total length */
  50     uint16_t ip_id;          /* identification */
  51     uint16_t ip_off;         /* fragment offset field */
  52     uint8_t  ip_ttl;         /* time to live */
  53     uint8_t  ip_p;           /* protocol */
  54     uint16_t ip_sum;         /* checksum */
  55     uint32_t ip_src, ip_dst; /* source and destination address */
  56 };
  57
  58 typedef struct tcp_header {
  59     uint16_t th_sport;          /* source port */
  60     uint16_t th_dport;          /* destination port */
  61     uint32_t th_seq;            /* sequence number */
  62     uint32_t th_ack;            /* acknowledgment number */
  63     uint16_t th_offset_flags;   /* data offset, reserved 6 bits, */
  64                                 /* TCP protocol flags */
  65     uint16_t th_win;            /* window */
  66     uint16_t th_sum;            /* checksum */
  67     uint16_t th_urp;            /* urgent pointer */
  68 } tcp_header;
  69
  70 #define TCP_FLAGS_ONLY(flags) ((flags) & 0x3f)
  71
  72 #define TCP_HEADER_FLAGS(tcp) \
  73     TCP_FLAGS_ONLY(be16_to_cpu((tcp)->th_offset_flags))
  74
  75 #define TCP_HEADER_DATA_OFFSET(tcp) \
  76     (((be16_to_cpu((tcp)->th_offset_flags) >> 12) & 0xf) << 2)
  77
  78 typedef struct udp_header {
  79     uint16_t uh_sport; /* source port */
  80     uint16_t uh_dport; /* destination port */
  81     uint16_t uh_ulen;  /* udp length */
  82     uint16_t uh_sum;   /* udp checksum */
  83 } udp_header;
  84
  85 typedef struct ip_pseudo_header {
  86     uint32_t ip_src;
  87     uint32_t ip_dst;
  88     uint8_t  zeros;
  89     uint8_t  ip_proto;
  90     uint16_t ip_payload;
  91 } ip_pseudo_header;
  92
  93 /* IPv6 address */
  94 struct in6_address {
  95     union {
  96         uint8_t __u6_addr8[16];
  97     } __in6_u;
  98 };
  99
 100 struct ip6_header {
 101     union {
 102         struct ip6_hdrctl {
 103             uint32_t ip6_un1_flow; /* 4 bits version, 8 bits TC,
 104                                       20 bits flow-ID */
 105             uint16_t ip6_un1_plen; /* payload length */
 106             uint8_t  ip6_un1_nxt;  /* next header */
 107             uint8_t  ip6_un1_hlim; /* hop limit */
 108         } ip6_un1;
 109         uint8_t ip6_un2_vfc;       /* 4 bits version, top 4 bits tclass */
 110         struct ip6_ecn_access {
 111             uint8_t  ip6_un3_vfc;  /* 4 bits version, top 4 bits tclass */
 112             uint8_t  ip6_un3_ecn;  /* 2 bits ECN, top 6 bits payload length */
 113         } ip6_un3;
 114     } ip6_ctlun;
 115     struct in6_address ip6_src;    /* source address */
 116     struct in6_address ip6_dst;    /* destination address */
 117 };
 118
 119 struct ip6_ext_hdr {
 120     uint8_t        ip6r_nxt;   /* next header */
 121     uint8_t        ip6r_len;   /* length in units of 8 octets */
 122 };
 123
 124 struct udp_hdr {
 125   uint16_t uh_sport;           /* source port */
 126   uint16_t uh_dport;           /* destination port */
 127   uint16_t uh_ulen;            /* udp length */
 128   uint16_t uh_sum;             /* udp checksum */
 129 };
 130
 131 struct tcp_hdr {
 132     u_short     th_sport;   /* source port */
 133     u_short     th_dport;   /* destination port */
 134     uint32_t    th_seq;     /* sequence number */
 135     uint32_t    th_ack;     /* acknowledgment number */
 136 #ifdef HOST_WORDS_BIGENDIAN
 137     u_char  th_off : 4,     /* data offset */
 138         th_x2:4;            /* (unused) */
 139 #else
 140     u_char  th_x2 : 4,      /* (unused) */
 141         th_off:4;           /* data offset */
 142 #endif
 143
 144 #define TH_ELN  0x1 /* explicit loss notification */
 145 #define TH_ECN  0x2 /* explicit congestion notification */
 146 #define TH_FS   0x4 /* fast start */
 147
 148     u_char  th_flags;
 149 #define TH_FIN  0x01
 150 #define TH_SYN  0x02
 151 #define TH_RST  0x04
 152 #define TH_PUSH 0x08
 153 #define TH_ACK  0x10
 154 #define TH_URG  0x20
 155     u_short th_win;      /* window */
 156     u_short th_sum;      /* checksum */
 157     u_short th_urp;      /* urgent pointer */
 158 };
 159
 160 #define ip6_nxt      ip6_ctlun.ip6_un1.ip6_un1_nxt
 161 #define ip6_ecn_acc  ip6_ctlun.ip6_un3.ip6_un3_ecn
 162
 163 #define PKT_GET_ETH_HDR(p)        \
 164     ((struct eth_header *)(p))
 165 #define PKT_GET_VLAN_HDR(p)       \
 166     ((struct vlan_header *) (((uint8_t *)(p)) + sizeof(struct eth_header)))
 167 #define PKT_GET_DVLAN_HDR(p)       \
 168     (PKT_GET_VLAN_HDR(p) + 1)
 169 #define PKT_GET_IP_HDR(p)         \
 170     ((struct ip_header *)(((uint8_t *)(p)) + eth_get_l2_hdr_length(p)))
 171 #define IP_HDR_GET_LEN(p)         \
 172     ((((struct ip_header *)p)->ip_ver_len & 0x0F) << 2)
 173 #define PKT_GET_IP_HDR_LEN(p)     \
 174     (IP_HDR_GET_LEN(PKT_GET_IP_HDR(p)))
 175 #define PKT_GET_IP6_HDR(p)        \
 176     ((struct ip6_header *) (((uint8_t *)(p)) + eth_get_l2_hdr_length(p)))
 177 #define IP_HEADER_VERSION(ip)     \
 178     ((ip->ip_ver_len >> 4)&0xf)
 179
 180 #define ETH_P_IP                  (0x0800)      /* Internet Protocol packet  */
 181 #define ETH_P_ARP                 (0x0806)      /* Address Resolution packet */
 182 #define ETH_P_IPV6                (0x86dd)
 183 #define ETH_P_VLAN                (0x8100)
 184 #define ETH_P_DVLAN               (0x88a8)
 185 #define VLAN_VID_MASK             0x0fff
 186 #define IP_HEADER_VERSION_4       (4)
 187 #define IP_HEADER_VERSION_6       (6)
 188 #define IP_PROTO_TCP              (6)
 189 #define IP_PROTO_UDP              (17)
 190 #define IPTOS_ECN_MASK            0x03
 191 #define IPTOS_ECN(x)              ((x) & IPTOS_ECN_MASK)
 192 #define IPTOS_ECN_CE              0x03
 193 #define IP6_ECN_MASK              0xC0
 194 #define IP6_ECN(x)                ((x) & IP6_ECN_MASK)
 195 #define IP6_ECN_CE                0xC0
 196 #define IP4_DONT_FRAGMENT_FLAG    (1 << 14)
 197
 198 #define IS_SPECIAL_VLAN_ID(x)     \
 199     (((x) == 0) || ((x) == 0xFFF))
 200
 201 #define ETH_MAX_L2_HDR_LEN  \
 202     (sizeof(struct eth_header) + 2 * sizeof(struct vlan_header))
 203
 204 #define ETH_MAX_IP4_HDR_LEN   (60)
 205 #define ETH_MAX_IP_DGRAM_LEN  (0xFFFF)
 206
 207 #define IP_FRAG_UNIT_SIZE     (8)
 208 #define IP_FRAG_ALIGN_SIZE(x) ((x) & ~0x7)
 209 #define IP_RF                 0x8000           /* reserved fragment flag */
 210 #define IP_DF                 0x4000           /* don't fragment flag */
 211 #define IP_MF                 0x2000           /* more fragments flag */
 212 #define IP_OFFMASK            0x1fff           /* mask for fragmenting bits */
 213
 214 #define IP6_EXT_GRANULARITY   (8)  /* Size granularity for
 215                                       IPv6 extension headers */
 216
 217 /* IP6 extension header types */
 218 #define IP6_HOP_BY_HOP        (0)
 219 #define IP6_ROUTING           (43)
 220 #define IP6_FRAGMENT          (44)
 221 #define IP6_ESP               (50)
 222 #define IP6_AUTHENTICATION    (51)
 223 #define IP6_NONE              (59)
 224 #define IP6_DESTINATON        (60)
 225 #define IP6_MOBILITY          (135)
 226
 227 static inline int is_multicast_ether_addr(const uint8_t *addr)
 228 {
 229     return 0x01 & addr[0];
 230 }
 231
 232 static inline int is_broadcast_ether_addr(const uint8_t *addr)
 233 {
 234     return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
 235 }
 236
 237 static inline int is_unicast_ether_addr(const uint8_t *addr)
 238 {
 239     return !is_multicast_ether_addr(addr);
 240 }
 241
 242 typedef enum {
 243     ETH_PKT_UCAST = 0xAABBCC00,
 244     ETH_PKT_BCAST,
 245     ETH_PKT_MCAST
 246 } eth_pkt_types_e;
 247
 248 static inline eth_pkt_types_e
 249 get_eth_packet_type(const struct eth_header *ehdr)
 250 {
 251     if (is_broadcast_ether_addr(ehdr->h_dest)) {
 252         return ETH_PKT_BCAST;
 253     } else if (is_multicast_ether_addr(ehdr->h_dest)) {
 254         return ETH_PKT_MCAST;
 255     } else { /* unicast */
 256         return ETH_PKT_UCAST;
 257     }
 258 }
 259
 260 static inline uint32_t
 261 eth_get_l2_hdr_length(const void *p)
 262 {
 263     uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 264     struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 265     switch (proto) {
 266     case ETH_P_VLAN:
 267         return sizeof(struct eth_header) + sizeof(struct vlan_header);
 268     case ETH_P_DVLAN:
 269         if (hvlan->h_proto == ETH_P_VLAN) {
 270             return sizeof(struct eth_header) + 2 * sizeof(struct vlan_header);
 271         } else {
 272             return sizeof(struct eth_header) + sizeof(struct vlan_header);
 273         }
 274     default:
 275         return sizeof(struct eth_header);
 276     }
 277 }
 278
 279 static inline uint16_t
 280 eth_get_pkt_tci(const void *p)
 281 {
 282     uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 283     struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 284     switch (proto) {
 285     case ETH_P_VLAN:
 286     case ETH_P_DVLAN:
 287         return be16_to_cpu(hvlan->h_tci);
 288     default:
 289         return 0;
 290     }
 291 }
 292
 293 static inline bool
 294 eth_strip_vlan(const void *p, uint8_t *new_ehdr_buf,
 295                uint16_t *payload_offset, uint16_t *tci)
 296 {
 297     uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
 298     struct vlan_header *hvlan = PKT_GET_VLAN_HDR(p);
 299     struct eth_header *new_ehdr = (struct eth_header *) new_ehdr_buf;
 300
 301     switch (proto) {
 302     case ETH_P_VLAN:
 303     case ETH_P_DVLAN:
 304         memcpy(new_ehdr->h_source, PKT_GET_ETH_HDR(p)->h_source, ETH_ALEN);
 305         memcpy(new_ehdr->h_dest, PKT_GET_ETH_HDR(p)->h_dest, ETH_ALEN);
 306         new_ehdr->h_proto = hvlan->h_proto;
 307         *tci = be16_to_cpu(hvlan->h_tci);
 308         *payload_offset =
 309             sizeof(struct eth_header) + sizeof(struct vlan_header);
 310         if (be16_to_cpu(new_ehdr->h_proto) == ETH_P_VLAN) {
 311             memcpy(PKT_GET_VLAN_HDR(new_ehdr),
 312                    PKT_GET_DVLAN_HDR(p),
 313                    sizeof(struct vlan_header));
 314             *payload_offset += sizeof(struct vlan_header);
 315         }
 316         return true;
 317     default:
 318         return false;
 319     }
 320 }
 321
 322 static inline uint16_t
 323 eth_get_l3_proto(const void *l2hdr, size_t l2hdr_len)
 324 {
 325     uint8_t *proto_ptr = (uint8_t *) l2hdr + l2hdr_len - sizeof(uint16_t);
 326     return be16_to_cpup((uint16_t *)proto_ptr);
 327 }
 328
 329 void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
 330     bool *is_new);
 331
 332 uint8_t eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto);
 333
 334 void eth_get_protocols(const uint8_t *headers,
 335                        uint32_t hdr_length,
 336                        bool *isip4, bool *isip6,
 337                        bool *isudp, bool *istcp);
 338
 339 void eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
 340                                  void *l3hdr, size_t l3hdr_len,
 341                                  size_t l3payload_len,
 342                                  size_t frag_offset, bool more_frags);
 343
 344 void
 345 eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len);
 346
 347 uint32_t
 348 eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl);
 349
 350 bool
 351 eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
 352                    size_t ip6hdr_off, uint8_t *l4proto,
 353                    size_t *full_hdr_len);
 354
 355 #endif