xref: /openbmc/qemu/net/colo.c (revision fe1127da)
1 /*
2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
3  * (a.k.a. Fault Tolerance or Continuous Replication)
4  *
5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
6  * Copyright (c) 2016 FUJITSU LIMITED
7  * Copyright (c) 2016 Intel Corporation
8  *
9  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or
12  * later.  See the COPYING file in the top-level directory.
13  */
14 
15 #include "qemu/osdep.h"
16 #include "trace.h"
17 #include "colo.h"
18 #include "util.h"
19 
20 uint32_t connection_key_hash(const void *opaque)
21 {
22     const ConnectionKey *key = opaque;
23     uint32_t a, b, c;
24 
25     /* Jenkins hash */
26     a = b = c = JHASH_INITVAL + sizeof(*key);
27     a += key->src.s_addr;
28     b += key->dst.s_addr;
29     c += (key->src_port | key->dst_port << 16);
30     __jhash_mix(a, b, c);
31 
32     a += key->ip_proto;
33     __jhash_final(a, b, c);
34 
35     return c;
36 }
37 
38 int connection_key_equal(const void *key1, const void *key2)
39 {
40     return memcmp(key1, key2, sizeof(ConnectionKey)) == 0;
41 }
42 
43 int parse_packet_early(Packet *pkt)
44 {
45     int network_length;
46     static const uint8_t vlan[] = {0x81, 0x00};
47     uint8_t *data = pkt->data + pkt->vnet_hdr_len;
48     uint16_t l3_proto;
49     ssize_t l2hdr_len = eth_get_l2_hdr_length(data);
50 
51     if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
52         trace_colo_proxy_main("pkt->size < ETH_HLEN");
53         return 1;
54     }
55 
56     /*
57      * TODO: support vlan.
58      */
59     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
60         trace_colo_proxy_main("COLO-proxy don't support vlan");
61         return 1;
62     }
63 
64     pkt->network_header = data + l2hdr_len;
65 
66     const struct iovec l2vec = {
67         .iov_base = (void *) data,
68         .iov_len = l2hdr_len
69     };
70     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
71 
72     if (l3_proto != ETH_P_IP) {
73         return 1;
74     }
75 
76     network_length = pkt->ip->ip_hl * 4;
77     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
78         trace_colo_proxy_main("pkt->size < network_header + network_length");
79         return 1;
80     }
81     pkt->transport_header = pkt->network_header + network_length;
82 
83     return 0;
84 }
85 
86 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key, Packet *pkt)
87 {
88         key->src = pkt->ip->ip_src;
89         key->dst = pkt->ip->ip_dst;
90         key->src_port = ntohs(tmp_ports >> 16);
91         key->dst_port = ntohs(tmp_ports & 0xffff);
92 }
93 
94 void fill_connection_key(Packet *pkt, ConnectionKey *key)
95 {
96     uint32_t tmp_ports;
97 
98     memset(key, 0, sizeof(*key));
99     key->ip_proto = pkt->ip->ip_p;
100 
101     switch (key->ip_proto) {
102     case IPPROTO_TCP:
103     case IPPROTO_UDP:
104     case IPPROTO_DCCP:
105     case IPPROTO_ESP:
106     case IPPROTO_SCTP:
107     case IPPROTO_UDPLITE:
108         tmp_ports = *(uint32_t *)(pkt->transport_header);
109         extract_ip_and_port(tmp_ports, key, pkt);
110         break;
111     case IPPROTO_AH:
112         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
113         extract_ip_and_port(tmp_ports, key, pkt);
114         break;
115     default:
116         break;
117     }
118 }
119 
120 void reverse_connection_key(ConnectionKey *key)
121 {
122     struct in_addr tmp_ip;
123     uint16_t tmp_port;
124 
125     tmp_ip = key->src;
126     key->src = key->dst;
127     key->dst = tmp_ip;
128 
129     tmp_port = key->src_port;
130     key->src_port = key->dst_port;
131     key->dst_port = tmp_port;
132 }
133 
134 Connection *connection_new(ConnectionKey *key)
135 {
136     Connection *conn = g_slice_new0(Connection);
137 
138     conn->ip_proto = key->ip_proto;
139     conn->processing = false;
140     conn->tcp_state = TCPS_CLOSED;
141     g_queue_init(&conn->primary_list);
142     g_queue_init(&conn->secondary_list);
143 
144     return conn;
145 }
146 
147 void connection_destroy(void *opaque)
148 {
149     Connection *conn = opaque;
150 
151     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
152     g_queue_clear(&conn->primary_list);
153     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
154     g_queue_clear(&conn->secondary_list);
155     g_slice_free(Connection, conn);
156 }
157 
158 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
159 {
160     Packet *pkt = g_slice_new(Packet);
161 
162     pkt->data = g_memdup(data, size);
163     pkt->size = size;
164     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
165     pkt->vnet_hdr_len = vnet_hdr_len;
166     pkt->tcp_seq = 0;
167     pkt->tcp_ack = 0;
168     pkt->seq_end = 0;
169     pkt->header_size = 0;
170     pkt->payload_size = 0;
171     pkt->offset = 0;
172     pkt->flags = 0;
173 
174     return pkt;
175 }
176 
177 void packet_destroy(void *opaque, void *user_data)
178 {
179     Packet *pkt = opaque;
180 
181     g_free(pkt->data);
182     g_slice_free(Packet, pkt);
183 }
184 
185 void packet_destroy_partial(void *opaque, void *user_data)
186 {
187     Packet *pkt = opaque;
188 
189     g_slice_free(Packet, pkt);
190 }
191 
192 /*
193  * Clear hashtable, stop this hash growing really huge
194  */
195 void connection_hashtable_reset(GHashTable *connection_track_table)
196 {
197     g_hash_table_remove_all(connection_track_table);
198 }
199 
200 /* if not found, create a new connection and add to hash table */
201 Connection *connection_get(GHashTable *connection_track_table,
202                            ConnectionKey *key,
203                            GQueue *conn_list)
204 {
205     Connection *conn = g_hash_table_lookup(connection_track_table, key);
206 
207     if (conn == NULL) {
208         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
209 
210         conn = connection_new(key);
211 
212         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
213             trace_colo_proxy_main("colo proxy connection hashtable full,"
214                                   " clear it");
215             connection_hashtable_reset(connection_track_table);
216             /*
217              * clear the conn_list
218              */
219             while (!g_queue_is_empty(conn_list)) {
220                 connection_destroy(g_queue_pop_head(conn_list));
221             }
222         }
223 
224         g_hash_table_insert(connection_track_table, new_key, conn);
225     }
226 
227     return conn;
228 }
229 
230 bool connection_has_tracked(GHashTable *connection_track_table,
231                             ConnectionKey *key)
232 {
233     Connection *conn = g_hash_table_lookup(connection_track_table, key);
234 
235     return conn ? true : false;
236 }
237