1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/*
* 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 */
assert(false);
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;
}
|
