qemu/net/announce.c

203 lines
5.8 KiB
C

/*
* 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_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);
}