/*
* QEMU network structures definitions and helper functions
*
* Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com)
*
* Developed by Daynix Computing LTD (http://www.daynix.com)
*
* Authors:
* Dmitry Fleytman <dmitry@daynix.com>
* Tamir Shomer <tamirs@daynix.com>
* Yan Vugenfirer <yan@daynix.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "net/eth.h"
#include "net/checksum.h"
#include "qemu-common.h"
#include "net/tap.h"
void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
bool *is_new)
{
struct vlan_header *vhdr = PKT_GET_VLAN_HDR(ehdr);
switch (be16_to_cpu(ehdr->h_proto)) {
case ETH_P_VLAN:
case ETH_P_DVLAN:
/* vlan hdr exists */
*is_new = false;
break;
default:
/* No VLAN header, put a new one */
vhdr->h_proto = ehdr->h_proto;
ehdr->h_proto = cpu_to_be16(ETH_P_VLAN);
*is_new = true;
break;
}
vhdr->h_tci = cpu_to_be16(vlan_tag);
}
uint8_t
eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto)
{
uint8_t ecn_state = 0;
if (l3_proto == ETH_P_IP) {
struct ip_header *iphdr = (struct ip_header *) l3_hdr;
if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
if (IPTOS_ECN(iphdr->ip_tos) == IPTOS_ECN_CE) {
ecn_state = VIRTIO_NET_HDR_GSO_ECN;
}
if (l4proto == IP_PROTO_TCP) {
return VIRTIO_NET_HDR_GSO_TCPV4 | ecn_state;
} else if (l4proto == IP_PROTO_UDP) {
return VIRTIO_NET_HDR_GSO_UDP | ecn_state;
}
}
} else if (l3_proto == ETH_P_IPV6) {
struct ip6_header *ip6hdr = (struct ip6_header *) l3_hdr;
if (IP6_ECN(ip6hdr->ip6_ecn_acc) == IP6_ECN_CE) {
ecn_state = VIRTIO_NET_HDR_GSO_ECN;
}
if (l4proto == IP_PROTO_TCP) {
return VIRTIO_NET_HDR_GSO_TCPV6 | ecn_state;
}
}
/* Unsupported offload */
g_assert_not_reached();
return VIRTIO_NET_HDR_GSO_NONE | ecn_state;
}
void eth_get_protocols(const uint8_t *headers,
uint32_t hdr_length,
bool *isip4, bool *isip6,
bool *isudp, bool *istcp)
{
int proto;
size_t l2hdr_len = eth_get_l2_hdr_length(headers);
assert(hdr_length >= eth_get_l2_hdr_length(headers));
*isip4 = *isip6 = *isudp = *istcp = false;
proto = eth_get_l3_proto(headers, l2hdr_len);
if (proto == ETH_P_IP) {
*isip4 = true;
struct ip_header *iphdr;
assert(hdr_length >=
eth_get_l2_hdr_length(headers) + sizeof(struct ip_header));
iphdr = PKT_GET_IP_HDR(headers);
if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
if (iphdr->ip_p == IP_PROTO_TCP) {
*istcp = true;
} else if (iphdr->ip_p == IP_PROTO_UDP) {
*isudp = true;
}
}
} else if (proto == ETH_P_IPV6) {
uint8_t l4proto;
size_t full_ip6hdr_len;
struct iovec hdr_vec;
hdr_vec.iov_base = (void *) headers;
hdr_vec.iov_len = hdr_length;
*isip6 = true;
if (eth_parse_ipv6_hdr(&hdr_vec, 1, l2hdr_len,
&l4proto, &full_ip6hdr_len)) {
if (l4proto == IP_PROTO_TCP) {
*istcp = true;
} else if (l4proto == IP_PROTO_UDP) {
*isudp = true;
}
}
}
}
void
eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
void *l3hdr, size_t l3hdr_len,
size_t l3payload_len,
size_t frag_offset, bool more_frags)
{
if (eth_get_l3_proto(l2hdr, l2hdr_len) == ETH_P_IP) {
uint16_t orig_flags;
struct ip_header *iphdr = (struct ip_header *) l3hdr;
uint16_t frag_off_units = frag_offset / IP_FRAG_UNIT_SIZE;
uint16_t new_ip_off;
assert(frag_offset % IP_FRAG_UNIT_SIZE == 0);
assert((frag_off_units & ~IP_OFFMASK) == 0);
orig_flags = be16_to_cpu(iphdr->ip_off) & ~(IP_OFFMASK|IP_MF);
new_ip_off = frag_off_units | orig_flags | (more_frags ? IP_MF : 0);
iphdr->ip_off = cpu_to_be16(new_ip_off);
iphdr->ip_len = cpu_to_be16(l3payload_len + l3hdr_len);
}
}
void
eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len)
{
struct ip_header *iphdr = (struct ip_header *) l3hdr;
iphdr->ip_sum = 0;
iphdr->ip_sum = cpu_to_be16(net_raw_checksum(l3hdr, l3hdr_len));
}
uint32_t
eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl)
{
struct ip_pseudo_header ipph;
ipph.ip_src = iphdr->ip_src;
ipph.ip_dst = iphdr->ip_dst;
ipph.ip_payload = cpu_to_be16(csl);
ipph.ip_proto = iphdr->ip_p;
ipph.zeros = 0;
return net_checksum_add(sizeof(ipph), (uint8_t *) &ipph);
}
static bool
eth_is_ip6_extension_header_type(uint8_t hdr_type)
{
switch (hdr_type) {
case IP6_HOP_BY_HOP:
case IP6_ROUTING:
case IP6_FRAGMENT:
case IP6_ESP:
case IP6_AUTHENTICATION:
case IP6_DESTINATON:
case IP6_MOBILITY:
return true;
default:
return false;
}
}
bool eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
size_t ip6hdr_off, uint8_t *l4proto,
size_t *full_hdr_len)
{
struct ip6_header ip6_hdr;
struct ip6_ext_hdr ext_hdr;
size_t bytes_read;
bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off,
&ip6_hdr, sizeof(ip6_hdr));
if (bytes_read < sizeof(ip6_hdr)) {
return false;
}
*full_hdr_len = sizeof(struct ip6_header);
if (!eth_is_ip6_extension_header_type(ip6_hdr.ip6_nxt)) {
*l4proto = ip6_hdr.ip6_nxt;
return true;
}
do {
bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off + *full_hdr_len,
&ext_hdr, sizeof(ext_hdr));
*full_hdr_len += (ext_hdr.ip6r_len + 1) * IP6_EXT_GRANULARITY;
} while (eth_is_ip6_extension_header_type(ext_hdr.ip6r_nxt));
*l4proto = ext_hdr.ip6r_nxt;
return true;
}
