Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging
[qemu.git] / net / filter-rewriter.c
1 /*
2 * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
3 * Copyright (c) 2016 FUJITSU LIMITED
4 * Copyright (c) 2016 Intel Corporation
5 *
6 * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
7 *
8 * This work is licensed under the terms of the GNU GPL, version 2 or
9 * later. See the COPYING file in the top-level directory.
10 */
11
12 #include "qemu/osdep.h"
13 #include "trace.h"
14 #include "net/colo.h"
15 #include "net/filter.h"
16 #include "net/net.h"
17 #include "qemu-common.h"
18 #include "qapi/error.h"
19 #include "qapi/qmp/qerror.h"
20 #include "qapi-visit.h"
21 #include "qom/object.h"
22 #include "qemu/main-loop.h"
23 #include "qemu/iov.h"
24 #include "net/checksum.h"
25
26 #define FILTER_COLO_REWRITER(obj) \
27 OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER)
28
29 #define TYPE_FILTER_REWRITER "filter-rewriter"
30
31 typedef struct RewriterState {
32 NetFilterState parent_obj;
33 NetQueue *incoming_queue;
34 /* hashtable to save connection */
35 GHashTable *connection_track_table;
36 } RewriterState;
37
38 static void filter_rewriter_flush(NetFilterState *nf)
39 {
40 RewriterState *s = FILTER_COLO_REWRITER(nf);
41
42 if (!qemu_net_queue_flush(s->incoming_queue)) {
43 /* Unable to empty the queue, purge remaining packets */
44 qemu_net_queue_purge(s->incoming_queue, nf->netdev);
45 }
46 }
47
48 /*
49 * Return 1 on success, if return 0 means the pkt
50 * is not TCP packet
51 */
52 static int is_tcp_packet(Packet *pkt)
53 {
54 if (!parse_packet_early(pkt) &&
55 pkt->ip->ip_p == IPPROTO_TCP) {
56 return 1;
57 } else {
58 return 0;
59 }
60 }
61
62 /* handle tcp packet from primary guest */
63 static int handle_primary_tcp_pkt(NetFilterState *nf,
64 Connection *conn,
65 Packet *pkt)
66 {
67 struct tcphdr *tcp_pkt;
68
69 tcp_pkt = (struct tcphdr *)pkt->transport_header;
70 if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) {
71 trace_colo_filter_rewriter_pkt_info(__func__,
72 inet_ntoa(pkt->ip->ip_src), inet_ntoa(pkt->ip->ip_dst),
73 ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack),
74 tcp_pkt->th_flags);
75 trace_colo_filter_rewriter_conn_offset(conn->offset);
76 }
77
78 if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_SYN)) {
79 /*
80 * we use this flag update offset func
81 * run once in independent tcp connection
82 */
83 conn->syn_flag = 1;
84 }
85
86 if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK)) {
87 if (conn->syn_flag) {
88 /*
89 * offset = secondary_seq - primary seq
90 * ack packet sent by guest from primary node,
91 * so we use th_ack - 1 get primary_seq
92 */
93 conn->offset -= (ntohl(tcp_pkt->th_ack) - 1);
94 conn->syn_flag = 0;
95 }
96 /* handle packets to the secondary from the primary */
97 tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset);
98
99 net_checksum_calculate((uint8_t *)pkt->data, pkt->size);
100 }
101
102 return 0;
103 }
104
105 /* handle tcp packet from secondary guest */
106 static int handle_secondary_tcp_pkt(NetFilterState *nf,
107 Connection *conn,
108 Packet *pkt)
109 {
110 struct tcphdr *tcp_pkt;
111
112 tcp_pkt = (struct tcphdr *)pkt->transport_header;
113
114 if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) {
115 trace_colo_filter_rewriter_pkt_info(__func__,
116 inet_ntoa(pkt->ip->ip_src), inet_ntoa(pkt->ip->ip_dst),
117 ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack),
118 tcp_pkt->th_flags);
119 trace_colo_filter_rewriter_conn_offset(conn->offset);
120 }
121
122 if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == (TH_ACK | TH_SYN))) {
123 /*
124 * save offset = secondary_seq and then
125 * in handle_primary_tcp_pkt make offset
126 * = secondary_seq - primary_seq
127 */
128 conn->offset = ntohl(tcp_pkt->th_seq);
129 }
130
131 if ((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK) {
132 /* handle packets to the primary from the secondary*/
133 tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset);
134
135 net_checksum_calculate((uint8_t *)pkt->data, pkt->size);
136 }
137
138 return 0;
139 }
140
141 static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
142 NetClientState *sender,
143 unsigned flags,
144 const struct iovec *iov,
145 int iovcnt,
146 NetPacketSent *sent_cb)
147 {
148 RewriterState *s = FILTER_COLO_REWRITER(nf);
149 Connection *conn;
150 ConnectionKey key;
151 Packet *pkt;
152 ssize_t size = iov_size(iov, iovcnt);
153 char *buf = g_malloc0(size);
154
155 iov_to_buf(iov, iovcnt, 0, buf, size);
156 pkt = packet_new(buf, size);
157 g_free(buf);
158
159 /*
160 * if we get tcp packet
161 * we will rewrite it to make secondary guest's
162 * connection established successfully
163 */
164 if (pkt && is_tcp_packet(pkt)) {
165
166 fill_connection_key(pkt, &key);
167
168 if (sender == nf->netdev) {
169 /*
170 * We need make tcp TX and RX packet
171 * into one connection.
172 */
173 reverse_connection_key(&key);
174 }
175 conn = connection_get(s->connection_track_table,
176 &key,
177 NULL);
178
179 if (sender == nf->netdev) {
180 /* NET_FILTER_DIRECTION_TX */
181 if (!handle_primary_tcp_pkt(nf, conn, pkt)) {
182 qemu_net_queue_send(s->incoming_queue, sender, 0,
183 (const uint8_t *)pkt->data, pkt->size, NULL);
184 packet_destroy(pkt, NULL);
185 pkt = NULL;
186 /*
187 * We block the packet here,after rewrite pkt
188 * and will send it
189 */
190 return 1;
191 }
192 } else {
193 /* NET_FILTER_DIRECTION_RX */
194 if (!handle_secondary_tcp_pkt(nf, conn, pkt)) {
195 qemu_net_queue_send(s->incoming_queue, sender, 0,
196 (const uint8_t *)pkt->data, pkt->size, NULL);
197 packet_destroy(pkt, NULL);
198 pkt = NULL;
199 /*
200 * We block the packet here,after rewrite pkt
201 * and will send it
202 */
203 return 1;
204 }
205 }
206 }
207
208 packet_destroy(pkt, NULL);
209 pkt = NULL;
210 return 0;
211 }
212
213 static void colo_rewriter_cleanup(NetFilterState *nf)
214 {
215 RewriterState *s = FILTER_COLO_REWRITER(nf);
216
217 /* flush packets */
218 if (s->incoming_queue) {
219 filter_rewriter_flush(nf);
220 g_free(s->incoming_queue);
221 }
222 }
223
224 static void colo_rewriter_setup(NetFilterState *nf, Error **errp)
225 {
226 RewriterState *s = FILTER_COLO_REWRITER(nf);
227
228 s->connection_track_table = g_hash_table_new_full(connection_key_hash,
229 connection_key_equal,
230 g_free,
231 connection_destroy);
232 s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
233 }
234
235 static void colo_rewriter_class_init(ObjectClass *oc, void *data)
236 {
237 NetFilterClass *nfc = NETFILTER_CLASS(oc);
238
239 nfc->setup = colo_rewriter_setup;
240 nfc->cleanup = colo_rewriter_cleanup;
241 nfc->receive_iov = colo_rewriter_receive_iov;
242 }
243
244 static const TypeInfo colo_rewriter_info = {
245 .name = TYPE_FILTER_REWRITER,
246 .parent = TYPE_NETFILTER,
247 .class_init = colo_rewriter_class_init,
248 .instance_size = sizeof(RewriterState),
249 };
250
251 static void register_types(void)
252 {
253 type_register_static(&colo_rewriter_info);
254 }
255
256 type_init(register_types);