Skip to content

Commit

Permalink
8503 snoop seems to delay packets doing DNS resolution
Browse files Browse the repository at this point in the history 
8504 traceroute should warn when name services are slow
8505 netstat should warn when name services are slow
8506 ping name service warnings should only happen once
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Yuri Pankov <yuripv@gmx.com>
Approved by: Gordon Ross <gwr@nexenta.com>
  • Loading branch information
@rmustacc
rmustacc committed Aug 8, 2017
1 parent f8cbe0e commit afee3dc
Show file tree
Hide file tree
Showing 4 changed files with 214 additions and 40 deletions.
108 changes: 98 additions & 10 deletions usr/src/cmd/cmd-inet/usr.bin/netstat/netstat.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
* Copyright (c) 1990 Mentat Inc.
* netstat.c 2.2, last change 9/9/91
* MROUTING Revision 3.5
* Copyright (c) 2017, Joyent, Inc.
*/

/*
Expand Down Expand Up @@ -55,6 +56,8 @@
#include <kstat.h>
#include <assert.h>
#include <locale.h>
#include <synch.h>
#include <thread.h>

#include <sys/types.h>
#include <sys/stream.h>
Expand Down Expand Up @@ -252,6 +255,15 @@ static int v4compat = 0; /* Compatible printing format for status */
static int proto = IPPROTO_MAX; /* all protocols */
kstat_ctl_t *kc = NULL;

/*
* Name service timeout detection constants.
*/
static mutex_t ns_lock = ERRORCHECKMUTEX;
static boolean_t ns_active = B_FALSE; /* Is a lookup ongoing? */
static hrtime_t ns_starttime; /* Time the lookup started */
static int ns_sleeptime = 2; /* Time in seconds between checks */
static int ns_warntime = 2; /* Time in seconds before warning */

/*
* Sizes of data structures extracted from the base mib.
* This allows the size of the tables entries to grow while preserving
Expand Down Expand Up @@ -349,6 +361,55 @@ static uint_t timestamp_fmt = NODATE;
#define TEXT_DOMAIN "SYS_TEST" /* Use this only if it isn't */
#endif

static void
ns_lookup_start(void)
{
mutex_enter(&ns_lock);
ns_active = B_TRUE;
ns_starttime = gethrtime();
mutex_exit(&ns_lock);
}

static void
ns_lookup_end(void)
{
mutex_enter(&ns_lock);
ns_active = B_FALSE;
mutex_exit(&ns_lock);
}

/*
* When name services are not functioning, this program appears to hang to the
* user. To try and give the user a chance of figuring out that this might be
* the case, we end up warning them and suggest that they may want to use the -n
* flag.
*/
/* ARGSUSED */
static void *
ns_warning_thr(void *unsued)
{
for (;;) {
hrtime_t now;

(void) sleep(ns_sleeptime);
now = gethrtime();
mutex_enter(&ns_lock);
if (ns_active && now - ns_starttime >= ns_warntime * NANOSEC) {
(void) fprintf(stderr, "warning: data "
"available, but name service lookups are "
"taking a while. Use the -n option to "
"disable name service lookups.\n");
mutex_exit(&ns_lock);
return (NULL);
}
mutex_exit(&ns_lock);
}

/* LINTED: E_STMT_NOT_REACHED */
return (NULL);
}


int
main(int argc, char **argv)
{
Expand Down Expand Up @@ -558,6 +619,15 @@ main(int argc, char **argv)
if (interval)
setbuf(stdout, NULL);

/*
* Start up the thread to check for name services warnings.
*/
if (thr_create(NULL, 0, ns_warning_thr, NULL,
THR_DETACHED | THR_DAEMON, NULL) != 0) {
fatal(1, "%s: failed to create name services "
"thread: %s\n", name, strerror(errno));
}

if (DHCPflag) {
dhcp_report(Iflag ? ifname : NULL);
exit(0);
Expand Down Expand Up @@ -972,7 +1042,8 @@ mib_item_dup(mib_item_t *item)
* for item->mib_id == 0
*/
static mib_item_t *
mib_item_diff(mib_item_t *item1, mib_item_t *item2) {
mib_item_diff(mib_item_t *item1, mib_item_t *item2)
{
int nitems = 0; /* no. of items in item2 */
mib_item_t *tempp2; /* walking copy of item2 */
mib_item_t *tempp1; /* walking copy of item1 */
Expand Down Expand Up @@ -1498,7 +1569,8 @@ mibdiff_out_of_memory:;
* mib_item_diff
*/
static void
mib_item_destroy(mib_item_t **itemp) {
mib_item_destroy(mib_item_t **itemp)
{
int nitems = 0;
int c = 0;
mib_item_t *tempp;
Expand Down Expand Up @@ -3264,8 +3336,9 @@ if_report(mib_item_t *item, char *matchname,

static void
if_report_ip4(mib2_ipAddrEntry_t *ap,
char ifname[], char logintname[], struct ifstat *statptr,
boolean_t ksp_not_null) {
char ifname[], char logintname[], struct ifstat *statptr,
boolean_t ksp_not_null)
{

char abuf[MAXHOSTNAMELEN + 1];
char dstbuf[MAXHOSTNAMELEN + 1];
Expand Down Expand Up @@ -3297,7 +3370,7 @@ if_report_ip4(mib2_ipAddrEntry_t *ap,
(void) printf("%-5s %-4u ", logintname, ap->ipAdEntInfo.ae_mtu);
if (ap->ipAdEntInfo.ae_flags & IFF_POINTOPOINT)
(void) pr_addr(ap->ipAdEntInfo.ae_pp_dst_addr, abuf,
sizeof (abuf));
sizeof (abuf));
else
(void) pr_netaddr(ap->ipAdEntAddr, ap->ipAdEntNetMask,
abuf, sizeof (abuf));
Expand All @@ -3312,8 +3385,9 @@ if_report_ip4(mib2_ipAddrEntry_t *ap,

static void
if_report_ip6(mib2_ipv6AddrEntry_t *ap6,
char ifname[], char logintname[], struct ifstat *statptr,
boolean_t ksp_not_null) {
char ifname[], char logintname[], struct ifstat *statptr,
boolean_t ksp_not_null)
{

char abuf[MAXHOSTNAMELEN + 1];
char dstbuf[MAXHOSTNAMELEN + 1];
Expand Down Expand Up @@ -5450,8 +5524,7 @@ plurales(int n)
}

static char *
pktscale(n)
int n;
pktscale(int n)
{
static char buf[6];
char t;
Expand Down Expand Up @@ -5735,8 +5808,10 @@ pr_addr(uint_t addr, char *dst, uint_t dstlen)
}
cp = NULL;
if (!Nflag) {
ns_lookup_start();
hp = getipnodebyaddr((char *)&addr, sizeof (uint_t), AF_INET,
&error_num);
ns_lookup_end();
if (hp) {
if ((cp = strchr(hp->h_name, '.')) != NULL &&
strcasecmp(cp + 1, domain) == 0)
Expand Down Expand Up @@ -5791,8 +5866,10 @@ pr_addr6(const struct in6_addr *addr, char *dst, uint_t dstlen)
}
cp = NULL;
if (!Nflag) {
ns_lookup_start();
hp = getipnodebyaddr((char *)addr,
sizeof (struct in6_addr), AF_INET6, &error_num);
ns_lookup_end();
if (hp) {
if ((cp = strchr(hp->h_name, '.')) != NULL &&
strcasecmp(cp + 1, domain) == 0)
Expand Down Expand Up @@ -5943,15 +6020,19 @@ pr_net(uint_t addr, uint_t mask, char *dst, uint_t dstlen)
net = addr & mask;
while ((mask & 1) == 0)
mask >>= 1, net >>= 1;
ns_lookup_start();
np = getnetbyaddr(net, AF_INET);
ns_lookup_end();
if (np && np->n_net == net)
cp = np->n_name;
else {
/*
* Look for subnets in hosts map.
*/
ns_lookup_start();
hp = getipnodebyaddr((char *)&addr, sizeof (uint_t),
AF_INET, &error_num);
ns_lookup_end();
if (hp)
cp = hp->h_name;
}
Expand Down Expand Up @@ -6025,15 +6106,19 @@ pr_netaddr(uint_t addr, uint_t mask, char *dst, uint_t dstlen)

/* Try looking up name unless -n was specified. */
if (!Nflag) {
ns_lookup_start();
np = getnetbyaddr(netshifted, AF_INET);
ns_lookup_end();
if (np && np->n_net == netshifted)
cp = np->n_name;
else {
/*
* Look for subnets in hosts map.
*/
ns_lookup_start();
hp = getipnodebyaddr((char *)&nbo_addr, sizeof (uint_t),
AF_INET, &error_num);
ns_lookup_end();
if (hp)
cp = hp->h_name;
}
Expand Down Expand Up @@ -6133,8 +6218,11 @@ portname(uint_t port, char *proto, char *dst, uint_t dstlen)
{
struct servent *sp = NULL;

if (!Nflag && port)
if (!Nflag && port) {
ns_lookup_start();
sp = getservbyport(htons(port), proto);
ns_lookup_end();
}
if (sp || port == 0)
(void) snprintf(dst, dstlen, "%.*s", MAXHOSTNAMELEN,
sp ? sp->s_name : "*");
Expand Down
22 changes: 9 additions & 13 deletions usr/src/cmd/cmd-inet/usr.sbin/ping/ping.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,7 @@
*/

/*
* Copyright 2015, Joyent, Inc.
* Copyright (c) 2017, Joyent, Inc.
*/

#include <assert.h>
Expand Down Expand Up @@ -187,7 +187,6 @@ static boolean_t ns_active = _B_FALSE; /* Lookup is going on */
static hrtime_t ns_starttime; /* Time the lookup started */
static int ns_sleeptime = 2; /* Time in seconds between checks */
static int ns_warntime = 2; /* Time in seconds before warning */
static int ns_warninter = 60; /* Time in seconds between warnings */

/*
* This buffer stores the received packets. Currently it needs to be 32 bit
Expand Down Expand Up @@ -1927,7 +1926,7 @@ send_scheduled_probe()
*/
static void
recv_icmp_packet(struct addrinfo *ai_dst, int recv_sock6, int recv_sock,
ushort_t udp_src_port6, ushort_t udp_src_port)
ushort_t udp_src_port6, ushort_t udp_src_port)
{
struct msghdr in_msg;
struct iovec iov;
Expand Down Expand Up @@ -2591,7 +2590,6 @@ ping_gettime(struct msghdr *msg, struct timeval *tv)
static void *
ns_warning_thr(void *unused)
{
hrtime_t last_warn = 0;
for (;;) {
hrtime_t now;

Expand All @@ -2600,15 +2598,13 @@ ns_warning_thr(void *unused)
mutex_enter(&ns_lock);
if (ns_active == _B_TRUE &&
now - ns_starttime >= ns_warntime * NANOSEC) {
if (now - last_warn >=
ns_warninter * NANOSEC) {
last_warn = now;
Fprintf(stderr, "%s: warning: ICMP responses "
"received, but name service lookups are "
"taking a while. Use ping -n to disable "
"name service lookups.\n",
progname);
}
Fprintf(stderr, "%s: warning: ICMP responses "
"received, but name service lookups are "
"taking a while. Use ping -n to disable "
"name service lookups.\n",
progname);
mutex_exit(&ns_lock);
return (NULL);
}
mutex_exit(&ns_lock);
}
Expand Down
Loading

0 comments on commit afee3dc

Please sign in to comment.