xref: /openbmc/qemu/net/colo.c (revision 2b74dd91)
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;
48     uint16_t l3_proto;
49     ssize_t l2hdr_len;
50 
51     assert(data);
52 
53     /* Check the received vnet_hdr_len then add the offset */
54     if ((pkt->vnet_hdr_len > sizeof(struct virtio_net_hdr_v1_hash)) ||
55         (pkt->size < sizeof(struct eth_header) + sizeof(struct vlan_header) +
56         pkt->vnet_hdr_len)) {
57         /*
58          * The received remote packet maybe misconfiguration here,
59          * Please enable/disable filter module's the vnet_hdr flag at
60          * the same time.
61          */
62         trace_colo_proxy_main_vnet_info("This received packet load wrong ",
63                                         pkt->vnet_hdr_len, pkt->size);
64         return 1;
65     }
66     data += pkt->vnet_hdr_len;
67 
68     l2hdr_len = eth_get_l2_hdr_length(data);
69 
70     /*
71      * TODO: support vlan.
72      */
73     if (!memcmp(&data[12], vlan, sizeof(vlan))) {
74         trace_colo_proxy_main("COLO-proxy don't support vlan");
75         return 1;
76     }
77 
78     pkt->network_header = data + l2hdr_len;
79 
80     const struct iovec l2vec = {
81         .iov_base = (void *) data,
82         .iov_len = l2hdr_len
83     };
84     l3_proto = eth_get_l3_proto(&l2vec, 1, l2hdr_len);
85 
86     if (l3_proto != ETH_P_IP) {
87         return 1;
88     }
89 
90     network_length = pkt->ip->ip_hl * 4;
91     if (pkt->size < l2hdr_len + network_length + pkt->vnet_hdr_len) {
92         trace_colo_proxy_main("pkt->size < network_header + network_length");
93         return 1;
94     }
95     pkt->transport_header = pkt->network_header + network_length;
96 
97     return 0;
98 }
99 
100 void extract_ip_and_port(uint32_t tmp_ports, ConnectionKey *key,
101                          Packet *pkt, bool reverse)
102 {
103     if (reverse) {
104         key->src = pkt->ip->ip_dst;
105         key->dst = pkt->ip->ip_src;
106         key->src_port = ntohs(tmp_ports & 0xffff);
107         key->dst_port = ntohs(tmp_ports >> 16);
108     } else {
109         key->src = pkt->ip->ip_src;
110         key->dst = pkt->ip->ip_dst;
111         key->src_port = ntohs(tmp_ports >> 16);
112         key->dst_port = ntohs(tmp_ports & 0xffff);
113     }
114 }
115 
116 void fill_connection_key(Packet *pkt, ConnectionKey *key, bool reverse)
117 {
118     uint32_t tmp_ports = 0;
119 
120     key->ip_proto = pkt->ip->ip_p;
121 
122     switch (key->ip_proto) {
123     case IPPROTO_TCP:
124     case IPPROTO_UDP:
125     case IPPROTO_DCCP:
126     case IPPROTO_ESP:
127     case IPPROTO_SCTP:
128     case IPPROTO_UDPLITE:
129         tmp_ports = *(uint32_t *)(pkt->transport_header);
130         break;
131     case IPPROTO_AH:
132         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
133         break;
134     default:
135         break;
136     }
137 
138     extract_ip_and_port(tmp_ports, key, pkt, reverse);
139 }
140 
141 Connection *connection_new(ConnectionKey *key)
142 {
143     Connection *conn = g_slice_new0(Connection);
144 
145     conn->ip_proto = key->ip_proto;
146     conn->processing = false;
147     conn->tcp_state = TCPS_CLOSED;
148     g_queue_init(&conn->primary_list);
149     g_queue_init(&conn->secondary_list);
150 
151     return conn;
152 }
153 
154 void connection_destroy(void *opaque)
155 {
156     Connection *conn = opaque;
157 
158     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
159     g_queue_clear(&conn->primary_list);
160     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
161     g_queue_clear(&conn->secondary_list);
162     g_slice_free(Connection, conn);
163 }
164 
165 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
166 {
167     Packet *pkt = g_slice_new0(Packet);
168 
169     pkt->data = g_memdup(data, size);
170     pkt->size = size;
171     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
172     pkt->vnet_hdr_len = vnet_hdr_len;
173 
174     return pkt;
175 }
176 
177 /*
178  * packet_new_nocopy will not copy data, so the caller can't release
179  * the data. And it will be released in packet_destroy.
180  */
181 Packet *packet_new_nocopy(void *data, int size, int vnet_hdr_len)
182 {
183     Packet *pkt = g_slice_new0(Packet);
184 
185     pkt->data = data;
186     pkt->size = size;
187     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
188     pkt->vnet_hdr_len = vnet_hdr_len;
189 
190     return pkt;
191 }
192 
193 void packet_destroy(void *opaque, void *user_data)
194 {
195     Packet *pkt = opaque;
196 
197     g_free(pkt->data);
198     g_slice_free(Packet, pkt);
199 }
200 
201 void packet_destroy_partial(void *opaque, void *user_data)
202 {
203     Packet *pkt = opaque;
204 
205     g_slice_free(Packet, pkt);
206 }
207 
208 /*
209  * Clear hashtable, stop this hash growing really huge
210  */
211 void connection_hashtable_reset(GHashTable *connection_track_table)
212 {
213     g_hash_table_remove_all(connection_track_table);
214 }
215 
216 /* if not found, create a new connection and add to hash table */
217 Connection *connection_get(GHashTable *connection_track_table,
218                            ConnectionKey *key,
219                            GQueue *conn_list)
220 {
221     Connection *conn = g_hash_table_lookup(connection_track_table, key);
222 
223     if (conn == NULL) {
224         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
225 
226         conn = connection_new(key);
227 
228         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
229             trace_colo_proxy_main("colo proxy connection hashtable full,"
230                                   " clear it");
231             connection_hashtable_reset(connection_track_table);
232             /*
233              * clear the conn_list
234              */
235             while (conn_list && !g_queue_is_empty(conn_list)) {
236                 connection_destroy(g_queue_pop_head(conn_list));
237             }
238         }
239 
240         g_hash_table_insert(connection_track_table, new_key, conn);
241     }
242 
243     return conn;
244 }
245 
246 bool connection_has_tracked(GHashTable *connection_track_table,
247                             ConnectionKey *key)
248 {
249     Connection *conn = g_hash_table_lookup(connection_track_table, key);
250 
251     return conn ? true : false;
252 }
253