Discussion:
[PATCH] Medium: tools: send_arp.libnet: reuse ARP packets
Dejan Muhamedagic
2013-03-13 17:19:10 UTC
Permalink
---
tools/send_arp.libnet.c | 174 ++++++++++++++++++++++++++++++++----------------
1 file changed, 115 insertions(+), 59 deletions(-)

diff --git a/tools/send_arp.libnet.c b/tools/send_arp.libnet.c
index 71148bb..2abeecb 100644
--- a/tools/send_arp.libnet.c
+++ b/tools/send_arp.libnet.c
@@ -49,17 +49,18 @@

#ifdef HAVE_LIBNET_1_0_API
# define LTYPE struct libnet_link_int
+ static u_char *mk_packet(u_int32_t ip, u_char *device, u_char *macaddr, u_char *broadcast, u_char *netmask, u_short arptype);
+ static int send_arp(struct libnet_link_int *l, u_char *device, u_char *buf);
#endif
#ifdef HAVE_LIBNET_1_1_API
# define LTYPE libnet_t
+ static libnet_t *mk_packet(libnet_t* lntag, u_int32_t ip, u_char *device, u_char macaddr[6], u_char *broadcast, u_char *netmask, u_short arptype);
+ int send_arp(libnet_t* lntag);
#endif

#define PIDDIR HA_VARRUNDIR "/" PACKAGE
#define PIDFILE_BASE PIDDIR "/send_arp-"

-static int send_arp(LTYPE* l, u_int32_t ip, u_char *device, u_char mac[6]
-, u_char *broadcast, u_char *netmask, u_short arptype);
-
static char print_usage[]={
"send_arp: sends out custom ARP packet.\n"
" usage: send_arp [-i repeatinterval-ms] [-r repeatcount] [-p pidfile] \\\n"
@@ -135,7 +136,6 @@ main(int argc, char *argv[])
char* netmask;
u_int32_t ip;
u_char src_mac[6];
- LTYPE* l;
int repeatcount = 1;
int j;
long msinterval = 1000;
@@ -143,6 +143,13 @@ main(int argc, char *argv[])
char pidfilenamebuf[64];
char *pidfilename = NULL;

+#ifdef HAVE_LIBNET_1_0_API
+ LTYPE* l;
+ u_char *request, *reply;
+#elif defined(HAVE_LIBNET_1_1_API)
+ LTYPE *request, *reply;
+#endif
+
CL_SIGNAL(SIGTERM, byebye);
CL_SIGINTERRUPT(SIGTERM, 1);

@@ -201,6 +208,24 @@ main(int argc, char *argv[])
return EXIT_FAILURE;
}

+ if (!strcasecmp(macaddr, AUTO_MAC_ADDR)) {
+ if (get_hw_addr(device, src_mac) < 0) {
+ cl_log(LOG_ERR, "Cannot find mac address for %s",
+ device);
+ unlink(pidfilename);
+ return EXIT_FAILURE;
+ }
+ }
+ else {
+ convert_macaddr((unsigned char *)macaddr, src_mac);
+ }
+
+/*
+ * We need to send both a broadcast ARP request as well as the ARP response we
+ * were already sending. All the interesting research work for this fix was
+ * done by Masaki Hasegawa <masaki-***@pp.iij4u.or.jp> and his colleagues.
+ */
+
#if defined(HAVE_LIBNET_1_0_API)
#ifdef ON_DARWIN
if ((ip = libnet_name_resolve((unsigned char*)ipaddr, 1)) == -1UL) {
@@ -219,49 +244,65 @@ main(int argc, char *argv[])
unlink(pidfilename);
return EXIT_FAILURE;
}
+ request = mk_packet(ip, (unsigned char*)device, src_mac
+ , (unsigned char*)broadcast, (unsigned char*)netmask
+ , ARPOP_REQUEST);
+ reply = mk_packet(ip, (unsigned char*)device, src_mac
+ , (unsigned char *)broadcast
+ , (unsigned char *)netmask, ARPOP_REPLY);
+ if (!request || !reply) {
+ cl_log(LOG_ERR, "could not create packets");
+ unlink(pidfilename);
+ return EXIT_FAILURE;
+ }
+ for (j=0; j < repeatcount; ++j) {
+ c = send_arp(l, (unsigned char*)device, request);
+ if (c < 0) {
+ break;
+ }
+ mssleep(msinterval / 2);
+ c = send_arp(l, (unsigned char*)device, reply);
+ if (c < 0) {
+ break;
+ }
+ if (j != repeatcount-1) {
+ mssleep(msinterval / 2);
+ }
+ }
#elif defined(HAVE_LIBNET_1_1_API)
- if ((l=libnet_init(LIBNET_LINK, device, errbuf)) == NULL) {
+ if ((request=libnet_init(LIBNET_LINK, device, errbuf)) == NULL) {
cl_log(LOG_ERR, "libnet_init failure on %s: %s", device, errbuf);
unlink(pidfilename);
return EXIT_FAILURE;
}
- if ((signed)(ip = libnet_name2addr4(l, ipaddr, 1)) == -1) {
- cl_log(LOG_ERR, "Cannot resolve IP address [%s]", ipaddr);
+ if ((reply=libnet_init(LIBNET_LINK, device, errbuf)) == NULL) {
+ cl_log(LOG_ERR, "libnet_init failure on %s: %s", device, errbuf);
unlink(pidfilename);
return EXIT_FAILURE;
}
-#else
-# error "Must have LIBNET API version defined."
-#endif
-
- if (!strcasecmp(macaddr, AUTO_MAC_ADDR)) {
- if (get_hw_addr(device, src_mac) < 0) {
- cl_log(LOG_ERR, "Cannot find mac address for %s",
- device);
- unlink(pidfilename);
- return EXIT_FAILURE;
- }
+ if ((signed)(ip = libnet_name2addr4(request, ipaddr, 1)) == -1) {
+ cl_log(LOG_ERR, "Cannot resolve IP address [%s]", ipaddr);
+ unlink(pidfilename);
+ return EXIT_FAILURE;
}
- else {
- convert_macaddr((unsigned char *)macaddr, src_mac);
+ request = mk_packet(request, ip, (unsigned char*)device, src_mac
+ , (unsigned char*)broadcast, (unsigned char*)netmask
+ , ARPOP_REQUEST);
+ reply = mk_packet(reply, ip, (unsigned char*)device, src_mac
+ , (unsigned char *)broadcast
+ , (unsigned char *)netmask, ARPOP_REPLY);
+ if (!request || !reply) {
+ cl_log(LOG_ERR, "could not create packets");
+ unlink(pidfilename);
+ return EXIT_FAILURE;
}
-
-/*
- * We need to send both a broadcast ARP request as well as the ARP response we
- * were already sending. All the interesting research work for this fix was
- * done by Masaki Hasegawa <masaki-***@pp.iij4u.or.jp> and his colleagues.
- */
for (j=0; j < repeatcount; ++j) {
- c = send_arp(l, ip, (unsigned char*)device, src_mac
- , (unsigned char*)broadcast, (unsigned char*)netmask
- , ARPOP_REQUEST);
+ c = send_arp(request);
if (c < 0) {
break;
}
mssleep(msinterval / 2);
- c = send_arp(l, ip, (unsigned char*)device, src_mac
- , (unsigned char *)broadcast
- , (unsigned char *)netmask, ARPOP_REPLY);
+ c = send_arp(reply);
if (c < 0) {
break;
}
@@ -269,6 +310,9 @@ main(int argc, char *argv[])
mssleep(msinterval / 2);
}
}
+#else
+# error "Must have LIBNET API version defined."
+#endif

unlink(pidfilename);
return c < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
@@ -387,10 +431,9 @@ get_hw_addr(char *device, u_char mac[6])
*/

#ifdef HAVE_LIBNET_1_0_API
-int
-send_arp(struct libnet_link_int *l, u_int32_t ip, u_char *device, u_char *macaddr, u_char *broadcast, u_char *netmask, u_short arptype)
+u_char *
+mk_packet(u_int32_t ip, u_char *device, u_char *macaddr, u_char *broadcast, u_char *netmask, u_short arptype)
{
- int n;
u_char *buf;
u_char *target_mac;
u_char device_mac[6];
@@ -400,7 +443,7 @@ send_arp(struct libnet_link_int *l, u_int32_t ip, u_char *device, u_char *macadd

if (libnet_init_packet(LIBNET_ARP_H + LIBNET_ETH_H, &buf) == -1) {
cl_log(LOG_ERR, "libnet_init_packet memory:");
- return -1;
+ return NULL;
}

/* Convert ASCII Mac Address to 6 Hex Digits. */
@@ -409,14 +452,14 @@ send_arp(struct libnet_link_int *l, u_int32_t ip, u_char *device, u_char *macadd
if (get_hw_addr((char*)device, device_mac) < 0) {
cl_log(LOG_ERR, "Cannot find mac address for %s",
device);
- return -1;
+ return NULL;
}

if (libnet_build_ethernet(bcast_mac, device_mac, ETHERTYPE_ARP, NULL, 0
, buf) == -1) {
cl_log(LOG_ERR, "libnet_build_ethernet failed:");
libnet_destroy_packet(&buf);
- return -1;
+ return NULL;
}

if (arptype == ARPOP_REQUEST) {
@@ -426,8 +469,8 @@ send_arp(struct libnet_link_int *l, u_int32_t ip, u_char *device, u_char *macadd
target_mac = macaddr;
}
else {
- cl_log(LOG_ERR, "unkonwn arptype:");
- return -1;
+ cl_log(LOG_ERR, "unknown arptype");
+ return NULL;
}

/*
@@ -447,16 +490,9 @@ send_arp(struct libnet_link_int *l, u_int32_t ip, u_char *device, u_char *macadd
buf + LIBNET_ETH_H) == -1) {
cl_log(LOG_ERR, "libnet_build_arp failed:");
libnet_destroy_packet(&buf);
- return -1;
+ return NULL;
}
-
- n = libnet_write_link_layer(l, (char*)device, buf, LIBNET_ARP_H + LIBNET_ETH_H);
- if (n == -1) {
- cl_log(LOG_ERR, "libnet_build_ethernet failed:");
- }
-
- libnet_destroy_packet(&buf);
- return (n);
+ return buf;
}
#endif /* HAVE_LIBNET_1_0_API */

@@ -464,10 +500,9 @@ send_arp(struct libnet_link_int *l, u_int32_t ip, u_char *device, u_char *macadd


#ifdef HAVE_LIBNET_1_1_API
-int
-send_arp(libnet_t* lntag, u_int32_t ip, u_char *device, u_char macaddr[6], u_char *broadcast, u_char *netmask, u_short arptype)
+libnet_t*
+mk_packet(libnet_t* lntag, u_int32_t ip, u_char *device, u_char macaddr[6], u_char *broadcast, u_char *netmask, u_short arptype)
{
- int n;
u_char *target_mac;
u_char device_mac[6];
u_char bcast_mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
@@ -481,7 +516,7 @@ send_arp(libnet_t* lntag, u_int32_t ip, u_char *device, u_char macaddr[6], u_cha
}
else {
cl_log(LOG_ERR, "unkonwn arptype:");
- return -1;
+ return NULL;
}

/*
@@ -502,28 +537,49 @@ send_arp(libnet_t* lntag, u_int32_t ip, u_char *device, u_char macaddr[6], u_cha
0 /* packet id */
) == -1 ) {
cl_log(LOG_ERR, "libnet_build_arp failed:");
- return -1;
+ return NULL;
}

/* Ethernet header */
if (get_hw_addr((char *)device, device_mac) < 0) {
cl_log(LOG_ERR, "Cannot find mac address for %s",
device);
- return -1;
+ return NULL;
}

if (libnet_build_ethernet(bcast_mac, device_mac, ETHERTYPE_ARP, NULL, 0
, lntag, 0) == -1 ) {
cl_log(LOG_ERR, "libnet_build_ethernet failed:");
- return -1;
+ return NULL;
}
+ return lntag;
+}
+#endif /* HAVE_LIBNET_1_1_API */

- n = libnet_write(lntag);
+#ifdef HAVE_LIBNET_1_0_API
+int
+send_arp(struct libnet_link_int *l, u_char *device, u_char *buf)
+{
+ int n;
+
+ n = libnet_write_link_layer(l, (char*)device, buf, LIBNET_ARP_H + LIBNET_ETH_H);
if (n == -1) {
- cl_log(LOG_ERR, "libnet_build_ethernet failed:");
+ cl_log(LOG_ERR, "libnet_write_link_layer failed");
}
- libnet_clear_packet(lntag);
+ return (n);
+}
+#endif /* HAVE_LIBNET_1_0_API */

+#ifdef HAVE_LIBNET_1_1_API
+int
+send_arp(libnet_t* lntag)
+{
+ int n;
+
+ n = libnet_write(lntag);
+ if (n == -1) {
+ cl_log(LOG_ERR, "libnet_write failed");
+ }
return (n);
}
#endif /* HAVE_LIBNET_1_1_API */
--
1.8.0


--y0ulUmNC+osPPQO6
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment; filename="sendarp.patch"

diff --git a/heartbeat/SendArp b/heartbeat/SendArp
index 553469b..611bb47 100755
--- a/heartbeat/SendArp
+++ b/heartbeat/SendArp
@@ -123,19 +123,6 @@ usage: $0 {start|stop|monitor|validate-all|meta-data}
Expects to have a fully populated OCF RA-compliant environment set.
END
}
-#
-# Check if ip-address is running.
-# We return stopped or running.
-#
-sendarp_status() {
- if
- [ -f "$SENDARPPIDFILE" ]
- then
- return $OCF_SUCCESS
- else
- return $OCF_NOT_RUNNING
- fi
-}

#
# Send gratuitous arp
@@ -144,12 +131,12 @@ sendarp_start() {

sendarp_validate
if [ $? = $OCF_ERR_ARGS ]; then
- return $OCF_ERR_ARGS;
+ return $OCF_ERR_ARGS
fi

- sendarp_status
+ sendarp_monitor
if [ $? = $OCF_SUCCESS ]; then
- return $OCF_SUCCESS;
+ return $OCF_SUCCESS
fi

[ -r ${HA_CONFDIR}/arp_config ] && . ${HA_CONFDIR}/arp_config
@@ -169,20 +156,21 @@ sendarp_start() {
$SENDARP $ARGS || (ocf_log err "Could not send gratuitous arps"; return $OCF_ERR_GENERIC)
;;
esac
- return $OCF_SUCCESS;
+ ha_pseudo_resource SendArp_${OCF_RESOURCE_INSTANCE} start
+ return $OCF_SUCCESS
}

#
# Stop sending gratuitous arp
#
sendarp_stop() {
- sendarp_validate
- if [ $? = $OCF_ERR_ARGS ]; then
- return $OCF_ERR_ARGS;
+ sendarp_monitor
+ if [ $? -eq $OCF_NOT_RUNNING ]; then
+ return $OCF_SUCCESS
fi
-
+
rc=$OCF_SUCCESS
-
+
if
[ -f "$SENDARPPIDFILE" ]
then
@@ -204,6 +192,7 @@ sendarp_stop() {
case $rc in
$OCF_SUCCESS)
ocf_log info "SendArp for $BASEIP/$INTERFACE released"
+ ha_pseudo_resource SendArp_${OCF_RESOURCE_INSTANCE} stop
;;
*)
ocf_log warn "SendArp for $BASEIP/$INTERFACE NOT released"
@@ -215,7 +204,7 @@ sendarp_stop() {
# This is always active, because it doesn't do much
#
sendarp_monitor() {
- return $OCF_SUCCESS
+ ha_pseudo_resource SendArp_${OCF_RESOURCE_INSTANCE} monitor
}

sendarp_validate() {
@@ -236,7 +225,7 @@ stop) sendarp_stop
;;
monitor) sendarp_monitor
;;
-status) sendarp_status
+status) sendarp_monitor
if [ $? = $OCF_SUCCESS ]; then
echo "running"
exit $OCF_SUCCESS;

--y0ulUmNC+osPPQO6--
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