summaryrefslogtreecommitdiff
path: root/net/announce.c
blob: db90d3bd4b91b3414201c7b39bad811beb68d487 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*
 *  Self-announce
 *  (c) 2017-2019 Red Hat, Inc.
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "qemu-common.h"
#include "net/announce.h"
#include "net/net.h"
#include "qapi/clone-visitor.h"
#include "qapi/qapi-visit-net.h"
#include "qapi/qapi-commands-net.h"
#include "trace.h"

static GData *named_timers;

int64_t qemu_announce_timer_step(AnnounceTimer *timer)
{
    int64_t step;

    step =  timer->params.initial +
            (timer->params.rounds - timer->round - 1) *
            timer->params.step;

    if (step < 0 || step > timer->params.max) {
        step = timer->params.max;
    }
    timer_mod(timer->tm, qemu_clock_get_ms(timer->type) + step);

    return step;
}

/*
 * If 'free_named' is true, then remove the timer from the list
 * and free the timer itself.
 */
void qemu_announce_timer_del(AnnounceTimer *timer, bool free_named)
{
    bool free_timer = false;
    if (timer->tm) {
        timer_del(timer->tm);
        timer_free(timer->tm);
        timer->tm = NULL;
    }
    qapi_free_strList(timer->params.interfaces);
    timer->params.interfaces = NULL;
    if (free_named && timer->params.has_id) {
        AnnounceTimer *list_timer;
        /*
         * Sanity check: There should only be one timer on the list with
         * the id.
         */
        list_timer = g_datalist_get_data(&named_timers, timer->params.id);
        assert(timer == list_timer);
        free_timer = true;
        g_datalist_remove_data(&named_timers, timer->params.id);
    }
    trace_qemu_announce_timer_del(free_named, free_timer, timer->params.id);
    g_free(timer->params.id);
    timer->params.id = NULL;

    if (free_timer) {
        g_free(timer);
    }
}

/*
 * Under BQL/main thread
 * Reset the timer to the given parameters/type/notifier.
 */
void qemu_announce_timer_reset(AnnounceTimer *timer,
                               AnnounceParameters *params,
                               QEMUClockType type,
                               QEMUTimerCB *cb,
                               void *opaque)
{
    /*
     * We're under the BQL, so the current timer can't
     * be firing, so we should be able to delete it.
     */
    qemu_announce_timer_del(timer, false);

    QAPI_CLONE_MEMBERS(AnnounceParameters, &timer->params, params);
    timer->round = params->rounds;
    timer->type = type;
    timer->tm = timer_new_ms(type, cb, opaque);
}

#ifndef ETH_P_RARP
#define ETH_P_RARP 0x8035
#endif
#define ARP_HTYPE_ETH 0x0001
#define ARP_PTYPE_IP 0x0800
#define ARP_OP_REQUEST_REV 0x3

static int announce_self_create(uint8_t *buf,
                                uint8_t *mac_addr)
{
    /* Ethernet header. */
    memset(buf, 0xff, 6);         /* destination MAC addr */
    memcpy(buf + 6, mac_addr, 6); /* source MAC addr */
    *(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */

    /* RARP header. */
    *(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */
    *(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */
    *(buf + 18) = 6; /* hardware addr length (ethernet) */
    *(buf + 19) = 4; /* protocol addr length (IPv4) */
    *(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */
    memcpy(buf + 22, mac_addr, 6); /* source hw addr */
    memset(buf + 28, 0x00, 4);     /* source protocol addr */
    memcpy(buf + 32, mac_addr, 6); /* target hw addr */
    memset(buf + 38, 0x00, 4);     /* target protocol addr */

    /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
    memset(buf + 42, 0x00, 18);

    return 60; /* len (FCS will be added by hardware) */
}

static void qemu_announce_self_iter(NICState *nic, void *opaque)
{
    AnnounceTimer *timer = opaque;
    uint8_t buf[60];
    int len;
    bool skip;

    if (timer->params.has_interfaces) {
        strList *entry = timer->params.interfaces;
        /* Skip unless we find our name in the requested list */
        skip = true;

        while (entry) {
            if (!strcmp(entry->value, nic->ncs->name)) {
                /* Found us */
                skip = false;
                break;
            }
            entry = entry->next;
        }
    } else {
        skip = false;
    }

    trace_qemu_announce_self_iter(timer->params.has_id ? timer->params.id : "_",
                                  nic->ncs->name,
                                  qemu_ether_ntoa(&nic->conf->macaddr), skip);

    if (!skip) {
        len = announce_self_create(buf, nic->conf->macaddr.a);

        qemu_send_packet_raw(qemu_get_queue(nic), buf, len);

        /* if the NIC provides it's own announcement support, use it as well */
        if (nic->ncs->info->announce) {
            nic->ncs->info->announce(nic->ncs);
        }
    }
}
static void qemu_announce_self_once(void *opaque)
{
    AnnounceTimer *timer = (AnnounceTimer *)opaque;

    qemu_foreach_nic(qemu_announce_self_iter, timer);

    if (--timer->round) {
        qemu_announce_timer_step(timer);
    } else {
        qemu_announce_timer_del(timer, true);
    }
}

void qemu_announce_self(AnnounceTimer *timer, AnnounceParameters *params)
{
    qemu_announce_timer_reset(timer, params, QEMU_CLOCK_REALTIME,
                              qemu_announce_self_once, timer);
    if (params->rounds) {
        qemu_announce_self_once(timer);
    } else {
        qemu_announce_timer_del(timer, true);
    }
}

void qmp_announce_self(AnnounceParameters *params, Error **errp)
{
    AnnounceTimer *named_timer;
    if (!params->has_id) {
        params->id = g_strdup("");
        params->has_id = true;
    }

    named_timer = g_datalist_get_data(&named_timers, params->id);

    if (!named_timer) {
        named_timer = g_new0(AnnounceTimer, 1);
        g_datalist_set_data(&named_timers, params->id, named_timer);
    }

    qemu_announce_self(named_timer, params);
}