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/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright 2015 Joyent, Inc.
*/
/*
* DNS Host-name related functions.
*
* For more information, see the big theory statement in
* lib/varpd/svp/common/libvarpd_svp.c.
*/
#include <sys/socket.h>
#include <netdb.h>
#include <thread.h>
#include <synch.h>
#include <assert.h>
#include <errno.h>
#include <libvarpd_svp.h>
int svp_host_nthreads = 8;
static mutex_t svp_host_lock = ERRORCHECKMUTEX;
static cond_t svp_host_cv = DEFAULTCV;
static svp_remote_t *svp_host_head;
/* ARGSUSED */
static void *
svp_host_loop(void *unused)
{
for (;;) {
int err;
svp_remote_t *srp;
struct addrinfo *addrs;
mutex_enter(&svp_host_lock);
while (svp_host_head == NULL)
(void) cond_wait(&svp_host_cv, &svp_host_lock);
srp = svp_host_head;
svp_host_head = srp->sr_nexthost;
if (svp_host_head != NULL)
(void) cond_signal(&svp_host_cv);
mutex_exit(&svp_host_lock);
mutex_enter(&srp->sr_lock);
assert(srp->sr_state & SVP_RS_LOOKUP_SCHEDULED);
srp->sr_state &= ~SVP_RS_LOOKUP_SCHEDULED;
if (srp->sr_state & SVP_RS_LOOKUP_INPROGRESS) {
mutex_exit(&srp->sr_lock);
continue;
}
srp->sr_state |= SVP_RS_LOOKUP_INPROGRESS;
mutex_exit(&srp->sr_lock);
for (;;) {
err = getaddrinfo(srp->sr_hostname, NULL, NULL, &addrs);
if (err == 0)
break;
if (err != 0) {
switch (err) {
case EAI_ADDRFAMILY:
case EAI_BADFLAGS:
case EAI_FAMILY:
case EAI_SERVICE:
case EAI_SOCKTYPE:
case EAI_OVERFLOW:
default:
libvarpd_panic("unexpected getaddrinfo "
"failure: %d", err);
break;
case EAI_AGAIN:
case EAI_MEMORY:
case EAI_SYSTEM:
continue;
case EAI_FAIL:
case EAI_NODATA:
case EAI_NONAME:
/*
* At this point in time we have
* something which isn't very good. This
* may have been a typo or something may
* have been destroyed. We should go
* ahead and degrade this overall
* instance, because we're not going to
* make much forward progress... It'd be
* great if we could actually issue more
* of an EREPORT to describe what
* happened, some day.
*/
mutex_enter(&srp->sr_lock);
svp_remote_degrade(srp,
SVP_RD_DNS_FAIL);
mutex_exit(&srp->sr_lock);
break;
}
}
break;
}
if (err == 0) {
/*
* We've successfully resolved something, mark this
* degredation over for now.
*/
mutex_enter(&srp->sr_lock);
svp_remote_restore(srp, SVP_RD_DNS_FAIL);
mutex_exit(&srp->sr_lock);
svp_remote_resolved(srp, addrs);
}
mutex_enter(&srp->sr_lock);
srp->sr_state &= ~SVP_RS_LOOKUP_INPROGRESS;
(void) cond_broadcast(&srp->sr_cond);
mutex_exit(&srp->sr_lock);
}
/* LINTED: E_STMT_NOT_REACHED */
return (NULL);
}
void
svp_host_queue(svp_remote_t *srp)
{
svp_remote_t *s;
mutex_enter(&svp_host_lock);
mutex_enter(&srp->sr_lock);
if (srp->sr_state & SVP_RS_LOOKUP_SCHEDULED) {
mutex_exit(&srp->sr_lock);
mutex_exit(&svp_host_lock);
return;
}
srp->sr_state |= SVP_RS_LOOKUP_SCHEDULED;
s = svp_host_head;
while (s != NULL && s->sr_nexthost != NULL)
s = s->sr_nexthost;
if (s == NULL) {
assert(s == svp_host_head);
svp_host_head = srp;
} else {
s->sr_nexthost = srp;
}
srp->sr_nexthost = NULL;
(void) cond_signal(&svp_host_cv);
mutex_exit(&srp->sr_lock);
mutex_exit(&svp_host_lock);
}
int
svp_host_init(void)
{
int i;
for (i = 0; i < svp_host_nthreads; i++) {
if (thr_create(NULL, 0, svp_host_loop, NULL,
THR_DETACHED | THR_DAEMON, NULL) != 0)
return (errno);
}
return (0);
}
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