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18#include "qemu/osdep.h"
19#include "net/eth.h"
20#include "net/checksum.h"
21#include "qemu-common.h"
22#include "net/tap.h"
23
24void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
25 bool *is_new)
26{
27 struct vlan_header *vhdr = PKT_GET_VLAN_HDR(ehdr);
28
29 switch (be16_to_cpu(ehdr->h_proto)) {
30 case ETH_P_VLAN:
31 case ETH_P_DVLAN:
32
33 *is_new = false;
34 break;
35
36 default:
37
38 vhdr->h_proto = ehdr->h_proto;
39 ehdr->h_proto = cpu_to_be16(ETH_P_VLAN);
40 *is_new = true;
41 break;
42 }
43 vhdr->h_tci = cpu_to_be16(vlan_tag);
44}
45
46uint8_t
47eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto)
48{
49 uint8_t ecn_state = 0;
50
51 if (l3_proto == ETH_P_IP) {
52 struct ip_header *iphdr = (struct ip_header *) l3_hdr;
53
54 if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
55 if (IPTOS_ECN(iphdr->ip_tos) == IPTOS_ECN_CE) {
56 ecn_state = VIRTIO_NET_HDR_GSO_ECN;
57 }
58 if (l4proto == IP_PROTO_TCP) {
59 return VIRTIO_NET_HDR_GSO_TCPV4 | ecn_state;
60 } else if (l4proto == IP_PROTO_UDP) {
61 return VIRTIO_NET_HDR_GSO_UDP | ecn_state;
62 }
63 }
64 } else if (l3_proto == ETH_P_IPV6) {
65 struct ip6_header *ip6hdr = (struct ip6_header *) l3_hdr;
66
67 if (IP6_ECN(ip6hdr->ip6_ecn_acc) == IP6_ECN_CE) {
68 ecn_state = VIRTIO_NET_HDR_GSO_ECN;
69 }
70
71 if (l4proto == IP_PROTO_TCP) {
72 return VIRTIO_NET_HDR_GSO_TCPV6 | ecn_state;
73 }
74 }
75
76
77 g_assert_not_reached();
78
79 return VIRTIO_NET_HDR_GSO_NONE | ecn_state;
80}
81
82void eth_get_protocols(const uint8_t *headers,
83 uint32_t hdr_length,
84 bool *isip4, bool *isip6,
85 bool *isudp, bool *istcp)
86{
87 int proto;
88 size_t l2hdr_len = eth_get_l2_hdr_length(headers);
89 assert(hdr_length >= eth_get_l2_hdr_length(headers));
90 *isip4 = *isip6 = *isudp = *istcp = false;
91
92 proto = eth_get_l3_proto(headers, l2hdr_len);
93 if (proto == ETH_P_IP) {
94 *isip4 = true;
95
96 struct ip_header *iphdr;
97
98 assert(hdr_length >=
99 eth_get_l2_hdr_length(headers) + sizeof(struct ip_header));
100
101 iphdr = PKT_GET_IP_HDR(headers);
102
103 if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
104 if (iphdr->ip_p == IP_PROTO_TCP) {
105 *istcp = true;
106 } else if (iphdr->ip_p == IP_PROTO_UDP) {
107 *isudp = true;
108 }
109 }
110 } else if (proto == ETH_P_IPV6) {
111 uint8_t l4proto;
112 size_t full_ip6hdr_len;
113
114 struct iovec hdr_vec;
115 hdr_vec.iov_base = (void *) headers;
116 hdr_vec.iov_len = hdr_length;
117
118 *isip6 = true;
119 if (eth_parse_ipv6_hdr(&hdr_vec, 1, l2hdr_len,
120 &l4proto, &full_ip6hdr_len)) {
121 if (l4proto == IP_PROTO_TCP) {
122 *istcp = true;
123 } else if (l4proto == IP_PROTO_UDP) {
124 *isudp = true;
125 }
126 }
127 }
128}
129
130void
131eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
132 void *l3hdr, size_t l3hdr_len,
133 size_t l3payload_len,
134 size_t frag_offset, bool more_frags)
135{
136 if (eth_get_l3_proto(l2hdr, l2hdr_len) == ETH_P_IP) {
137 uint16_t orig_flags;
138 struct ip_header *iphdr = (struct ip_header *) l3hdr;
139 uint16_t frag_off_units = frag_offset / IP_FRAG_UNIT_SIZE;
140 uint16_t new_ip_off;
141
142 assert(frag_offset % IP_FRAG_UNIT_SIZE == 0);
143 assert((frag_off_units & ~IP_OFFMASK) == 0);
144
145 orig_flags = be16_to_cpu(iphdr->ip_off) & ~(IP_OFFMASK|IP_MF);
146 new_ip_off = frag_off_units | orig_flags | (more_frags ? IP_MF : 0);
147 iphdr->ip_off = cpu_to_be16(new_ip_off);
148 iphdr->ip_len = cpu_to_be16(l3payload_len + l3hdr_len);
149 }
150}
151
152void
153eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len)
154{
155 struct ip_header *iphdr = (struct ip_header *) l3hdr;
156 iphdr->ip_sum = 0;
157 iphdr->ip_sum = cpu_to_be16(net_raw_checksum(l3hdr, l3hdr_len));
158}
159
160uint32_t
161eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl)
162{
163 struct ip_pseudo_header ipph;
164 ipph.ip_src = iphdr->ip_src;
165 ipph.ip_dst = iphdr->ip_dst;
166 ipph.ip_payload = cpu_to_be16(csl);
167 ipph.ip_proto = iphdr->ip_p;
168 ipph.zeros = 0;
169 return net_checksum_add(sizeof(ipph), (uint8_t *) &ipph);
170}
171
172static bool
173eth_is_ip6_extension_header_type(uint8_t hdr_type)
174{
175 switch (hdr_type) {
176 case IP6_HOP_BY_HOP:
177 case IP6_ROUTING:
178 case IP6_FRAGMENT:
179 case IP6_ESP:
180 case IP6_AUTHENTICATION:
181 case IP6_DESTINATON:
182 case IP6_MOBILITY:
183 return true;
184 default:
185 return false;
186 }
187}
188
189bool eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
190 size_t ip6hdr_off, uint8_t *l4proto,
191 size_t *full_hdr_len)
192{
193 struct ip6_header ip6_hdr;
194 struct ip6_ext_hdr ext_hdr;
195 size_t bytes_read;
196
197 bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off,
198 &ip6_hdr, sizeof(ip6_hdr));
199 if (bytes_read < sizeof(ip6_hdr)) {
200 return false;
201 }
202
203 *full_hdr_len = sizeof(struct ip6_header);
204
205 if (!eth_is_ip6_extension_header_type(ip6_hdr.ip6_nxt)) {
206 *l4proto = ip6_hdr.ip6_nxt;
207 return true;
208 }
209
210 do {
211 bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off + *full_hdr_len,
212 &ext_hdr, sizeof(ext_hdr));
213 *full_hdr_len += (ext_hdr.ip6r_len + 1) * IP6_EXT_GRANULARITY;
214 } while (eth_is_ip6_extension_header_type(ext_hdr.ip6r_nxt));
215
216 *l4proto = ext_hdr.ip6r_nxt;
217 return true;
218}
219
