/*
Description: Wrapper around DHCP client to restart it when the interface
moves to another network.
Authors: Arnout Vandecappelle <arnout@mind.be>, Essensium/Mind
Maarten Van Es <maarten@mind.be>, Essensium/Mind
(C) Septentrio 2008
The license and distribution terms for this file may be
found in the file LICENSE in this distribution or at
http://www.rtems.org/license/LICENSE.
To use this functionality, call rtems_bsdnet_do_dhcp_failsafe() or set it
as the bootp member of the rtems_bsdnet_config structure.
The rtems_bsdnet_do_dhcp_failsafe() function provides the following
functionalities:
* It starts DHCP on the first non-loopback, non-point-to-point interface.
Before DHCP is started, any existing IP address on that interface is
removed, as well as the default route.
* If DHCP fails to acquire an address for whatever reason, the interface
is reconfigured with the static address provided in its
rtems_bsdnet_ifconfig structure, and the default route from
rtems_bsdnet_config is restored.
It is possible to change the address in the rtems_bsdnet_ifconfig structure
while the system is running.
* Optionally, after the interface is configured (either with DHCP or
statically), a task is started to monitor it. When the interface remains
disconnected (i.e. its IFF_RUNNING flag is off) for network_fail_timeout
seconds, the dhcp lease renewal is stopped. As soon as the interface is
connected again, DHCP is started again as above.
If network_fail_timeout is set to 0, the monitor task is not started.
* Optionally, when the interface is disconnected, it is also brought down
for network_down_time seconds. Since this possibly makes the IFF_RUNNING
flag unuseable, the interface is brought up again before the flag is
polled.
If network_down_time is set to 0, the interface is not brought down.
* Optionally, before DHCP is started, we wait for broadcast_delay seconds.
This is necessary to allow some routers to perform spanning tree discovery.
Note that DHCP doesn't work well with multiple interfaces: only one of them
is configured using DHCP, and we can't guarantee it's the same one that is
monitored by this function.
*/
#include <rtems.h>
#include <rtems/error.h>
#include <rtems/rtems_bsdnet.h>
#include <rtems/rtems_bsdnet_internal.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <rtems/dhcp.h>
#include <rtems/rtems_dhcp_failsafe.h>
struct proc; /* Unused parameter of some functions. */
#include <sys/sockio.h>
#include <sys/socket.h>
#include <net/route.h>
#include <netinet/in.h> /* for sockaddr_in */
#include <net/if.h> /* for if.h */
#include <net/if_var.h> /* for in_var.h */
#include <netinet/in_var.h> /* for in_aliasreq */
#include <sys/sockio.h> /* for ioctl definitions */
static int network_fail_timeout = RTEMS_DHCP_FAILSAFE_NETWORK_FAIL_TIMEOUT;
static int network_down_time = RTEMS_DHCP_FAILSAFE_NETWORK_DOWN_TIME;
static int broadcast_delay = RTEMS_DHCP_FAILSAFE_BROADCAST_DELAY;
static int dhcp_monitor_priority = RTEMS_DHCP_FAILSAFE_DHCP_MONITOR_PRIORITY;
void rtems_bsdnet_dhcp_failsafe_config(
int network_fail_timeout_,
int network_down_time_,
int broadcast_delay_,
int dhcp_monitor_priority_
)
{
network_fail_timeout = network_fail_timeout_;
network_down_time = network_down_time_;
broadcast_delay = broadcast_delay_;
dhcp_monitor_priority = dhcp_monitor_priority_;
}
/*
* returns 0 when successful, negative value for failure
*/
static int remove_address(const char *if_name)
{
struct sockaddr_in address;
struct in_aliasreq ifra;
int retval = 0;
memset (&address, '\0', sizeof (address));
address.sin_len = sizeof (address);
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
/* Remove old default route to 0.0.0.0 */
if (rtems_bsdnet_rtrequest (RTM_DELETE, (struct sockaddr *)&address, NULL,
(struct sockaddr *)&address,
(RTF_UP | RTF_STATIC), NULL) < 0 ) {
printf ("Failed to delete default route: %s (%d)\n", strerror (errno), errno);
retval = -1;
}
/* Remove old ip-address */
if (rtems_bsdnet_ifconfig(if_name, SIOCGIFADDR, &address) < 0) {
printf ("Failed to get if address: %s (%d)\n", strerror (errno), errno);
return -1;
}
strncpy (ifra.ifra_name, if_name, IFNAMSIZ);
memcpy (&ifra.ifra_addr, &address, sizeof(address));
if (rtems_bsdnet_ifconfig(if_name, SIOCDIFADDR, &ifra)) {
printf ("Can't delete if address: %s (%d)\n", strerror (errno), errno);
return -1;
}
return retval;
}
static int
dhcp_if_down (const char* ifname)
{
int16_t flags;
if (rtems_bsdnet_ifconfig (ifname, SIOCGIFFLAGS, &flags) < 0) {
printf ("Can't get flags for %s: %s\n", ifname, strerror (errno));
return -1;
}
if (flags & IFF_UP) {
flags &= ~IFF_UP;
if (rtems_bsdnet_ifconfig (ifname, SIOCSIFFLAGS, &flags) < 0) {
printf ("Can't bring %s down: %s\n", ifname, strerror (errno));
return -1;
}
}
return 0;
}
static int
dhcp_if_up (const char* ifname)
{
int16_t flags;
if (rtems_bsdnet_ifconfig (ifname, SIOCGIFFLAGS, &flags) < 0) {
printf ("Can't get flags for %s: %s\n", ifname, strerror (errno));
return -1;
}
if (!(flags & IFF_UP)) {
flags |= IFF_UP;
if (rtems_bsdnet_ifconfig (ifname, SIOCSIFFLAGS, &flags) < 0) {
printf ("Can't bring %s up: %s\n", ifname, strerror (errno));
return -1;
}
}
return 0;
}
static int
set_static_address (struct rtems_bsdnet_ifconfig *ifp)
{
int16_t flags;
struct sockaddr_in address;
struct sockaddr_in netmask;
struct sockaddr_in broadcast;
struct sockaddr_in gateway;
if (ifp->ip_address != NULL) {
printf("Setting static address for interface %s.\n", ifp->name);
/*
* Bring interface up
*/
if (dhcp_if_up (ifp->name) < 0)
return -1;
/*
* Set interface netmask
*/
memset (&netmask, '\0', sizeof netmask);
netmask.sin_len = sizeof netmask;
netmask.sin_family = AF_INET;
netmask.sin_addr.s_addr = inet_addr (ifp->ip_netmask);
if (rtems_bsdnet_ifconfig (ifp->name, SIOCSIFNETMASK, &netmask) < 0) {
printf ("Can't set %s netmask: %s\n", ifp->name, strerror (errno));
return -1;
}
/*
* Set interface address
*/
memset (&address, '\0', sizeof address);
address.sin_len = sizeof address;
address.sin_family = AF_INET;
address.sin_addr.s_addr = inet_addr (ifp->ip_address);
if (rtems_bsdnet_ifconfig (ifp->name, SIOCSIFADDR, &address) < 0) {
printf ("Can't set %s address: %s\n", ifp->name, strerror (errno));
return -1;
}
/*
* Set interface broadcast address if the interface has the
* broadcast flag set.
*/
if (rtems_bsdnet_ifconfig (ifp->name, SIOCGIFFLAGS, &flags) < 0) {
printf ("Can't read %s flags: %s\n", ifp->name, strerror (errno));
return -1;
}
if (flags & IFF_BROADCAST) {
memset (&broadcast, '\0', sizeof broadcast);
broadcast.sin_len = sizeof broadcast;
broadcast.sin_family = AF_INET;
broadcast.sin_addr.s_addr = address.sin_addr.s_addr | ~netmask.sin_addr.s_addr;
if (rtems_bsdnet_ifconfig (ifp->name, SIOCSIFBRDADDR, &broadcast) < 0) {
struct in_addr in_addr;
char buf[20];
in_addr.s_addr = broadcast.sin_addr.s_addr;
if (!inet_ntop (AF_INET, &in_addr, buf, sizeof (buf)))
strcpy (buf, "?.?.?.?");
printf ("Can't set %s broadcast address %s: %s\n", ifp->name, buf, strerror (errno));
}
}
}
/*
* Set default route
*/
if (rtems_bsdnet_config.gateway) {
address.sin_addr.s_addr = INADDR_ANY;
netmask.sin_addr.s_addr = INADDR_ANY;
memset (&gateway, '\0', sizeof gateway);
gateway.sin_len = sizeof gateway;
gateway.sin_family = AF_INET;
gateway.sin_addr.s_addr = inet_addr (rtems_bsdnet_config.gateway);
if (rtems_bsdnet_rtrequest (RTM_ADD,
(struct sockaddr *) &address,
(struct sockaddr *) &gateway,
(struct sockaddr *) &netmask,
(RTF_UP | RTF_GATEWAY | RTF_STATIC),
NULL
) < 0) {
printf ("Can't set default route: %s\n", strerror (errno));
return -1;
}
}
return 0;
}
static void
do_dhcp_init (struct rtems_bsdnet_ifconfig *ifp)
{
if (broadcast_delay) {
/* Wait before sending broadcast. */
rtems_task_wake_after(RTEMS_MILLISECONDS_TO_TICKS(broadcast_delay * 1000));
}
printf ("starting dhcp client...\n");
remove_address(ifp->name);
if (rtems_bsdnet_do_dhcp_timeout () != 0) {
remove_address(ifp->name);
set_static_address (ifp); /* use static ip-address if dhcp failed */
}
}
/*
* Main dhcp monitor thread
*/
static void dhcp_monitor_task (rtems_task_argument ifp_arg)
{
struct rtems_bsdnet_ifconfig *ifp = (struct rtems_bsdnet_ifconfig *)ifp_arg;
char *ifname = ifp->name;
unsigned int downcount = 0;
int16_t ifflags;
int must_renew = FALSE;
while (TRUE) {
if (rtems_bsdnet_ifconfig(ifname, SIOCGIFFLAGS, &ifflags) < 0) {
printf ("Failed to get if flags: %s (%d)\n", strerror (errno), errno);
goto error_out;
}
if ((ifflags & IFF_RUNNING) != 0) {
if(must_renew) {
must_renew = FALSE;
do_dhcp_init(ifp);
}
downcount = 0;
} else {
if (downcount < network_fail_timeout) {
downcount++;
if (downcount == network_fail_timeout) {
printf ("lost network connection...\n");
rtems_bsdnet_dhcp_down ();
must_renew = TRUE;
dhcp_if_down(ifname);
rtems_task_wake_after(RTEMS_MILLISECONDS_TO_TICKS(network_down_time * 1000));
dhcp_if_up(ifname);
downcount = 0;
}
}
}
rtems_task_wake_after(RTEMS_MILLISECONDS_TO_TICKS(1000));
}
error_out:
printf("Stopping dhcp monitoring application.\n");
rtems_task_delete(RTEMS_SELF);
}
/*
* initialize dhcp monitoring application
* start dhcp monitoring thread
*/
void rtems_bsdnet_do_dhcp_failsafe (void)
{
rtems_status_code sc;
rtems_id id;
struct rtems_bsdnet_ifconfig *ifp;
int16_t ifflags;
/* Find a suitable interface */
for (ifp = rtems_bsdnet_config.ifconfig; ifp; ifp = ifp->next) {
if (rtems_bsdnet_ifconfig (ifp->name, SIOCGIFFLAGS, &ifflags) < 0)
continue;
if ((ifflags & (IFF_LOOPBACK | IFF_POINTOPOINT)) == 0)
break;
}
if (ifp == NULL){
printf ("dhcpc_failsafe: no suitable interface\n");
return;
}
printf("starting dhcp on interface %s\n", ifp->name);
do_dhcp_init(ifp);
if (network_fail_timeout) {
sc = rtems_task_create (rtems_build_name ('d','h','c','m'),
dhcp_monitor_priority,
2048,
RTEMS_PREEMPT |
RTEMS_NO_TIMESLICE |
RTEMS_NO_ASR |
RTEMS_INTERRUPT_LEVEL (0),
RTEMS_LOCAL,
&id);
if (sc != RTEMS_SUCCESSFUL) {
printf ("Failed to create dhcp monitor task, code %d\n", sc);
return;
}
sc = rtems_task_start (id, dhcp_monitor_task, (rtems_task_argument) ifp);
if (sc != RTEMS_SUCCESSFUL) {
printf ("Failed to start dhcp monitor task, code %d\n", sc);
}
}
}
