qemu

announce.c (6215B)

---

 /*
  *  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/cutils.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) */
 }
 
 /*
  * Helper to print ethernet mac address
  */
 static const char *qemu_ether_ntoa(const MACAddr *mac)
 {
     static char ret[18];
 
     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 
     return ret;
 }
 
 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);
 }