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
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*
* Copyright (c) 2023 Red Hat, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include <stdlib.h>
#include <string.h>
#include "dp-packet.h"
#include "dp-packet-gso.h"
#include "netdev-provider.h"
#include "openvswitch/vlog.h"
VLOG_DEFINE_THIS_MODULE(dp_packet_gso);
/* Retuns a new packet that is a segment of packet 'p'.
*
* The new packet is initialized with 'hdr_len' bytes from the
* start of packet 'p' and then appended with 'data_len' bytes
* from the 'data' buffer.
*
* Note: The packet headers are not updated. */
static struct dp_packet *
dp_packet_gso_seg_new(const struct dp_packet *p, size_t hdr_len,
const char *data, size_t data_len)
{
struct dp_packet *seg = dp_packet_new_with_headroom(hdr_len + data_len,
dp_packet_headroom(p));
/* Append the original packet headers and then the payload. */
dp_packet_put(seg, dp_packet_data(p), hdr_len);
dp_packet_put(seg, data, data_len);
/* The new segment should have the same offsets. */
seg->l2_5_ofs = p->l2_5_ofs;
seg->l3_ofs = p->l3_ofs;
seg->l4_ofs = p->l4_ofs;
seg->inner_l3_ofs = p->inner_l3_ofs;
seg->inner_l4_ofs = p->inner_l4_ofs;
/* The protocol headers remain the same, so preserve hash and mark. */
seg->has_hash = p->has_hash;
*dp_packet_rss_ptr(seg) = *dp_packet_rss_ptr(p);
seg->has_mark = p->has_mark;
*dp_packet_flow_mark_ptr(seg) = *dp_packet_flow_mark_ptr(p);
seg->offloads = p->offloads;
return seg;
}
/* Returns the calculated number of TCP segments in packet 'p'. */
int
dp_packet_gso_nr_segs(struct dp_packet *p)
{
uint16_t segsz = dp_packet_get_tso_segsz(p);
const char *data_tail;
const char *data_pos;
if (dp_packet_tunnel(p)) {
data_pos = dp_packet_get_inner_tcp_payload(p);
} else {
data_pos = dp_packet_get_tcp_payload(p);
}
data_tail = (char *) dp_packet_tail(p) - dp_packet_l2_pad_size(p);
return DIV_ROUND_UP(data_tail - data_pos, segsz);
}
/* Perform software segmentation on packet 'p'.
*
* Segments packet 'p' into the array of preallocated batches in 'batches',
* updating the 'batches' pointer as needed and returns true.
*
* Returns false if the packet cannot be segmented. */
bool
dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
{
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
struct dp_packet_batch *curr_batch = *batches;
struct tcp_header *tcp_hdr;
struct ip_header *ip_hdr;
uint16_t inner_ip_id = 0;
uint16_t outer_ip_id = 0;
struct dp_packet *seg;
uint16_t tcp_offset;
uint16_t tso_segsz;
uint32_t tcp_seq;
bool outer_ipv4;
int hdr_len;
int seg_len;
bool udp_tnl = dp_packet_tunnel_vxlan(p)
|| dp_packet_tunnel_geneve(p);
bool gre_tnl = dp_packet_tunnel_gre(p);
tso_segsz = dp_packet_get_tso_segsz(p);
if (!tso_segsz) {
VLOG_WARN_RL(&rl, "GSO packet with len %d with no segment size.",
dp_packet_size(p));
return false;
}
if (udp_tnl || gre_tnl) {
ip_hdr = dp_packet_inner_l3(p);
if (IP_VER(ip_hdr->ip_ihl_ver) == 4) {
inner_ip_id = ntohs(ip_hdr->ip_id);
}
tcp_hdr = dp_packet_inner_l4(p);
} else {
tcp_hdr = dp_packet_l4(p);
}
ip_hdr = dp_packet_l3(p);
outer_ipv4 = IP_VER(ip_hdr->ip_ihl_ver) == 4;
if (outer_ipv4) {
outer_ip_id = ntohs(ip_hdr->ip_id);
}
tcp_offset = TCP_OFFSET(tcp_hdr->tcp_ctl);
tcp_seq = ntohl(get_16aligned_be32(&tcp_hdr->tcp_seq));
hdr_len = ((char *) tcp_hdr - (char *) dp_packet_eth(p))
+ tcp_offset * 4;
const char *data_tail = (char *) dp_packet_tail(p)
- dp_packet_l2_pad_size(p);
const char *data_pos = (char *) tcp_hdr + tcp_offset * 4;
int n_segs = dp_packet_gso_nr_segs(p);
for (int i = 0; i < n_segs; i++) {
seg_len = data_tail - data_pos;
if (seg_len > tso_segsz) {
seg_len = tso_segsz;
}
seg = dp_packet_gso_seg_new(p, hdr_len, data_pos, seg_len);
data_pos += seg_len;
if (udp_tnl) {
/* Update tunnel UDP header length. */
struct udp_header *tnl_hdr;
tnl_hdr = dp_packet_l4(seg);
tnl_hdr->udp_len = htons(dp_packet_l4_size(seg));
dp_packet_l4_checksum_set_partial(seg);
}
if (udp_tnl || gre_tnl) {
/* Update tunnel inner L3 header. */
ip_hdr = dp_packet_inner_l3(seg);
if (IP_VER(ip_hdr->ip_ihl_ver) == 4) {
ip_hdr->ip_tot_len = htons(dp_packet_inner_l3_size(seg));
ip_hdr->ip_id = htons(inner_ip_id);
ip_hdr->ip_csum = 0;
dp_packet_inner_ip_checksum_set_partial(seg);
inner_ip_id++;
} else {
struct ovs_16aligned_ip6_hdr *ip6_hdr;
ip6_hdr = dp_packet_inner_l3(seg);
ip6_hdr->ip6_ctlun.ip6_un1.ip6_un1_plen
= htons(dp_packet_inner_l3_size(seg) - sizeof *ip6_hdr);
}
}
/* Update L3 header. */
if (outer_ipv4) {
ip_hdr = dp_packet_l3(seg);
ip_hdr->ip_tot_len = htons(dp_packet_l3_size(seg));
ip_hdr->ip_id = htons(outer_ip_id);
ip_hdr->ip_csum = 0;
dp_packet_ip_checksum_set_partial(seg);
outer_ip_id++;
} else {
struct ovs_16aligned_ip6_hdr *ip6_hdr = dp_packet_l3(seg);
ip6_hdr->ip6_ctlun.ip6_un1.ip6_un1_plen
= htons(dp_packet_l3_size(seg) - sizeof *ip6_hdr);
}
/* Update L4 header. */
if (udp_tnl || gre_tnl) {
tcp_hdr = dp_packet_inner_l4(seg);
dp_packet_inner_l4_checksum_set_partial(seg);
} else {
tcp_hdr = dp_packet_l4(seg);
dp_packet_l4_checksum_set_partial(seg);
}
put_16aligned_be32(&tcp_hdr->tcp_seq, htonl(tcp_seq));
tcp_seq += seg_len;
if (OVS_LIKELY(i < (n_segs - 1))) {
/* Reset flags PUSH and FIN unless it is the last segment. */
uint16_t tcp_flags = TCP_FLAGS(tcp_hdr->tcp_ctl)
& ~(TCP_PSH | TCP_FIN);
tcp_hdr->tcp_ctl = TCP_CTL(tcp_flags, tcp_offset);
}
if (gre_tnl) {
struct gre_base_hdr *ghdr;
ghdr = dp_packet_l4(seg);
if (ghdr->flags & htons(GRE_CSUM)) {
ovs_be16 *csum_opt = (ovs_be16 *) (ghdr + 1);
*csum_opt = 0;
*csum_opt = csum(ghdr, dp_packet_l4_size(seg));
}
}
if (dp_packet_batch_is_full(curr_batch)) {
curr_batch++;
}
dp_packet_batch_add(curr_batch, seg);
}
*batches = curr_batch;
return true;
}
|
