xref: /openbmc/qemu/net/colo.c (revision 9c489ea6)
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 fill_connection_key(Packet *pkt, ConnectionKey *key)
86 {
87     uint32_t tmp_ports;
88 
89     memset(key, 0, sizeof(*key));
90     key->ip_proto = pkt->ip->ip_p;
91 
92     switch (key->ip_proto) {
93     case IPPROTO_TCP:
94     case IPPROTO_UDP:
95     case IPPROTO_DCCP:
96     case IPPROTO_ESP:
97     case IPPROTO_SCTP:
98     case IPPROTO_UDPLITE:
99         tmp_ports = *(uint32_t *)(pkt->transport_header);
100         key->src = pkt->ip->ip_src;
101         key->dst = pkt->ip->ip_dst;
102         key->src_port = ntohs(tmp_ports & 0xffff);
103         key->dst_port = ntohs(tmp_ports >> 16);
104         break;
105     case IPPROTO_AH:
106         tmp_ports = *(uint32_t *)(pkt->transport_header + 4);
107         key->src = pkt->ip->ip_src;
108         key->dst = pkt->ip->ip_dst;
109         key->src_port = ntohs(tmp_ports & 0xffff);
110         key->dst_port = ntohs(tmp_ports >> 16);
111         break;
112     default:
113         break;
114     }
115 }
116 
117 void reverse_connection_key(ConnectionKey *key)
118 {
119     struct in_addr tmp_ip;
120     uint16_t tmp_port;
121 
122     tmp_ip = key->src;
123     key->src = key->dst;
124     key->dst = tmp_ip;
125 
126     tmp_port = key->src_port;
127     key->src_port = key->dst_port;
128     key->dst_port = tmp_port;
129 }
130 
131 Connection *connection_new(ConnectionKey *key)
132 {
133     Connection *conn = g_slice_new(Connection);
134 
135     conn->ip_proto = key->ip_proto;
136     conn->processing = false;
137     conn->offset = 0;
138     conn->syn_flag = 0;
139     g_queue_init(&conn->primary_list);
140     g_queue_init(&conn->secondary_list);
141 
142     return conn;
143 }
144 
145 void connection_destroy(void *opaque)
146 {
147     Connection *conn = opaque;
148 
149     g_queue_foreach(&conn->primary_list, packet_destroy, NULL);
150     g_queue_clear(&conn->primary_list);
151     g_queue_foreach(&conn->secondary_list, packet_destroy, NULL);
152     g_queue_clear(&conn->secondary_list);
153     g_slice_free(Connection, conn);
154 }
155 
156 Packet *packet_new(const void *data, int size, int vnet_hdr_len)
157 {
158     Packet *pkt = g_slice_new(Packet);
159 
160     pkt->data = g_memdup(data, size);
161     pkt->size = size;
162     pkt->creation_ms = qemu_clock_get_ms(QEMU_CLOCK_HOST);
163     pkt->vnet_hdr_len = vnet_hdr_len;
164 
165     return pkt;
166 }
167 
168 void packet_destroy(void *opaque, void *user_data)
169 {
170     Packet *pkt = opaque;
171 
172     g_free(pkt->data);
173     g_slice_free(Packet, pkt);
174 }
175 
176 /*
177  * Clear hashtable, stop this hash growing really huge
178  */
179 void connection_hashtable_reset(GHashTable *connection_track_table)
180 {
181     g_hash_table_remove_all(connection_track_table);
182 }
183 
184 /* if not found, create a new connection and add to hash table */
185 Connection *connection_get(GHashTable *connection_track_table,
186                            ConnectionKey *key,
187                            GQueue *conn_list)
188 {
189     Connection *conn = g_hash_table_lookup(connection_track_table, key);
190 
191     if (conn == NULL) {
192         ConnectionKey *new_key = g_memdup(key, sizeof(*key));
193 
194         conn = connection_new(key);
195 
196         if (g_hash_table_size(connection_track_table) > HASHTABLE_MAX_SIZE) {
197             trace_colo_proxy_main("colo proxy connection hashtable full,"
198                                   " clear it");
199             connection_hashtable_reset(connection_track_table);
200             /*
201              * clear the conn_list
202              */
203             while (!g_queue_is_empty(conn_list)) {
204                 connection_destroy(g_queue_pop_head(conn_list));
205             }
206         }
207 
208         g_hash_table_insert(connection_track_table, new_key, conn);
209     }
210 
211     return conn;
212 }
213