xref: /openbmc/qemu/net/colo.c (revision 8f0a3716)
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 "net/colo.h"
18 
19 uint32_t connection_key_hash(const void *opaque)
20 {
21     const ConnectionKey *key = opaque;
22     uint32_t a, b, c;
23 
24     /* Jenkins hash */
25     a = b = c = JHASH_INITVAL + sizeof(*key);
26     a += key->src.s_addr;
27     b += key->dst.s_addr;
28     c += (key->src_port | key->dst_port << 16);
29     __jhash_mix(a, b, c);
30 
31     a += key->ip_proto;
32     __jhash_final(a, b, c);
33 
34     return c;
35 }
36 
37 int connection_key_equal(const void *key1, const void *key2)
38 {
39     return memcmp(key1, key2, sizeof(ConnectionKey)) == 0;
40 }
41 
42 int parse_packet_early(Packet *pkt)
43 {
44     int network_length;
45     static const uint8_t vlan[] = {0x81, 0x00};
46     uint8_t *data = pkt->data + pkt->vnet_hdr_len;
47     uint16_t l3_proto;
48     ssize_t l2hdr_len = eth_get_l2_hdr_length(data);
49 
50     if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
51         trace_colo_proxy_main("pkt->size < ETH_HLEN");
52         return 1;
53     }
54 
55     /*
56      * TODO: support vlan.
57      */
58     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
59         trace_colo_proxy_main("COLO-proxy don't support vlan");
60         return 1;
61     }
62 
63     pkt->network_header = data + l2hdr_len;
64 
65     const struct iovec l2vec = {
66         .iov_base = (void *) data,
67         .iov_len = l2hdr_len
68     };
69     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
70 
71     if (l3_proto != ETH_P_IP) {
72         return 1;
73     }
74 
75     network_length = pkt->ip->ip_hl * 4;
76     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
77         trace_colo_proxy_main("pkt->size < network_header + network_length");
78         return 1;
79     }
80     pkt->transport_header = pkt->network_header + network_length;
81 
82     return 0;
83 }
84 
85 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key, Packet *pkt)
86 {
87         key->src = pkt->ip->ip_src;
88         key->dst = pkt->ip->ip_dst;
89         key->src_port = ntohs(tmp_ports >> 16);
90         key->dst_port = ntohs(tmp_ports & 0xffff);
91 }
92 
93 void fill_connection_key(Packet *pkt, ConnectionKey *key)
94 {
95     uint32_t tmp_ports;
96 
97     memset(key, 0, sizeof(*key));
98     key->ip_proto = pkt->ip->ip_p;
99 
100     switch (key->ip_proto) {
101     case IPPROTO_TCP:
102     case IPPROTO_UDP:
103     case IPPROTO_DCCP:
104     case IPPROTO_ESP:
105     case IPPROTO_SCTP:
106     case IPPROTO_UDPLITE:
107         tmp_ports = *(uint32_t *)(pkt->transport_header);
108         extract_ip_and_port(tmp_ports, key, pkt);
109         break;
110     case IPPROTO_AH:
111         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
112         extract_ip_and_port(tmp_ports, key, pkt);
113         break;
114     default:
115         break;
116     }
117 }
118 
119 void reverse_connection_key(ConnectionKey *key)
120 {
121     struct in_addr tmp_ip;
122     uint16_t tmp_port;
123 
124     tmp_ip = key->src;
125     key->src = key->dst;
126     key->dst = tmp_ip;
127 
128     tmp_port = key->src_port;
129     key->src_port = key->dst_port;
130     key->dst_port = tmp_port;
131 }
132 
133 Connection *connection_new(ConnectionKey *key)
134 {
135     Connection *conn = g_slice_new(Connection);
136 
137     conn->ip_proto = key->ip_proto;
138     conn->processing = false;
139     conn->offset = 0;
140     conn->syn_flag = 0;
141     conn->pack = 0;
142     conn->sack = 0;
143     g_queue_init(&conn->primary_list);
144     g_queue_init(&conn->secondary_list);
145 
146     return conn;
147 }
148 
149 void connection_destroy(void *opaque)
150 {
151     Connection *conn = opaque;
152 
153     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
154     g_queue_clear(&conn->primary_list);
155     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
156     g_queue_clear(&conn->secondary_list);
157     g_slice_free(Connection, conn);
158 }
159 
160 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
161 {
162     Packet *pkt = g_slice_new(Packet);
163 
164     pkt->data = g_memdup(data, size);
165     pkt->size = size;
166     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
167     pkt->vnet_hdr_len = vnet_hdr_len;
168     pkt->tcp_seq = 0;
169     pkt->tcp_ack = 0;
170     pkt->seq_end = 0;
171     pkt->header_size = 0;
172     pkt->payload_size = 0;
173     pkt->offset = 0;
174     pkt->flags = 0;
175 
176     return pkt;
177 }
178 
179 void packet_destroy(void *opaque, void *user_data)
180 {
181     Packet *pkt = opaque;
182 
183     g_free(pkt->data);
184     g_slice_free(Packet, pkt);
185 }
186 
187 /*
188  * Clear hashtable, stop this hash growing really huge
189  */
190 void connection_hashtable_reset(GHashTable *connection_track_table)
191 {
192     g_hash_table_remove_all(connection_track_table);
193 }
194 
195 /* if not found, create a new connection and add to hash table */
196 Connection *connection_get(GHashTable *connection_track_table,
197                            ConnectionKey *key,
198                            GQueue *conn_list)
199 {
200     Connection *conn = g_hash_table_lookup(connection_track_table, key);
201 
202     if (conn == NULL) {
203         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
204 
205         conn = connection_new(key);
206 
207         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
208             trace_colo_proxy_main("colo proxy connection hashtable full,"
209                                   " clear it");
210             connection_hashtable_reset(connection_track_table);
211             /*
212              * clear the conn_list
213              */
214             while (!g_queue_is_empty(conn_list)) {
215                 connection_destroy(g_queue_pop_head(conn_list));
216             }
217         }
218 
219         g_hash_table_insert(connection_track_table, new_key, conn);
220     }
221 
222     return conn;
223 }
224