Commit 87202683 authored by Francis Dupont's avatar Francis Dupont
Browse files

Reliable DHCPv6 release

parent 843ae4c5
......@@ -95,6 +95,9 @@ work on other platforms. Please report any problems and suggested fixes to
- Basic and partial DHCPv6 leasequery support.
- Reliable DHCPv6 release (previous behavior, send release and exit, is
still available with dhclient -6 -1 -r).
Changes since 4.0.0 (bug fixes)
- DHCP now builds on AIX.
......
......@@ -74,6 +74,7 @@ static isc_result_t dhc6_add_ia_na(struct client_state *client,
struct data_string *packet,
struct dhc6_lease *lease,
u_int8_t message);
static isc_boolean_t stopping_finished(void);
static void dhc6_merge_lease(struct dhc6_lease *src, struct dhc6_lease *dst);
void do_select6(void *input);
void do_refresh6(void *input);
......@@ -1683,16 +1684,15 @@ start_release6(struct client_state *client)
client->active_lease->released = ISC_TRUE;
write_client6_lease(client, client->active_lease, 0, 1);
/* Set timers per RFC3315 section 18.1.1. */
/* Set timers per RFC3315 section 18.1.6. */
client->IRT = REL_TIMEOUT * 100;
client->MRT = 0;
client->MRC = REL_MAX_RC * 100;
client->MRC = REL_MAX_RC;
client->MRD = 0;
dhc6_retrans_init(client);
client->v6_handler = reply_handler;
/* ("re")transmit the first packet. */
do_release6(client);
}
/*
......@@ -1701,10 +1701,8 @@ start_release6(struct client_state *client)
static void
do_release6(void *input)
{
struct sockaddr_in6 unicast, *dest_addr = &DHCPv6DestAddr;
struct client_state *client;
struct data_string ds;
struct option_cache *oc;
int send_ret;
struct timeval tv;
......@@ -1715,7 +1713,7 @@ do_release6(void *input)
if ((client->MRC != 0) && (client->txcount > client->MRC)) {
log_info("Max retransmission count exceeded.");
return;
goto release_done;
}
/*
......@@ -1727,31 +1725,14 @@ do_release6(void *input)
}
/*
* Check whether the server has sent a unicast option; if so, we can
* use the address it specified.
* Don't use unicast as we don't know if we still have an
* available address with enough scope.
*/
oc = lookup_option(&dhcpv6_universe,
client->active_lease->options, D6O_UNICAST);
if (oc && evaluate_option_cache(&ds, NULL, NULL, NULL,
client->active_lease->options,
NULL, &global_scope, oc, MDL)) {
if (ds.len < 16) {
log_error("Invalid unicast option length %d.", ds.len);
} else {
memset(&unicast, 0, sizeof(DHCPv6DestAddr));
unicast.sin6_family = AF_INET6;
unicast.sin6_port = remote_port;
memcpy(&unicast.sin6_addr, ds.data, 16);
dest_addr = &unicast;
}
data_string_forget(&ds, MDL);
}
memset(&ds, 0, sizeof(ds));
if (!buffer_allocate(&ds.buffer, 4, MDL)) {
log_error("Unable to allocate memory for Release.");
return;
goto release_done;
}
ds.data = ds.buffer->data;
......@@ -1770,7 +1751,7 @@ do_release6(void *input)
if (dhc6_add_ia_na(client, &ds, client->active_lease,
DHCPV6_RELEASE) != ISC_R_SUCCESS) {
data_string_forget(&ds, MDL);
return;
goto release_done;
}
/* Transmit and wait. */
......@@ -1796,6 +1777,13 @@ do_release6(void *input)
}
add_timeout(&tv, do_release6, client, NULL, NULL);
dhc6_retrans_advance(client);
return;
release_done:
dhc6_lease_destroy(&client->active_lease, MDL);
client->active_lease = NULL;
if (stopping_finished())
exit(0);
}
/* status_log() just puts a status code into displayable form and logs it
......@@ -1814,6 +1802,7 @@ status_log(int code, const char *scope, const char *additional, int len)
case STATUS_UnspecFail:
msg = "UnspecFail";
break;
case STATUS_NoAddrsAvail:
msg = "NoAddrsAvail";
break;
......@@ -1972,13 +1961,18 @@ dhc6_check_advertise(struct dhc6_lease *lease)
* (rapid/commit). Returns always false as no action is defined.
*/
static isc_boolean_t
dhc6_init_action(struct client_state *client, isc_result_t rval,
dhc6_init_action(struct client_state *client, isc_result_t *rvalp,
unsigned code)
{
if (client == NULL)
return ISC_R_INVALIDARG;
if (rvalp == NULL)
log_fatal("Impossible condition at %s:%d.", MDL);
if (rval == ISC_R_SUCCESS)
if (client == NULL) {
*rvalp = ISC_R_INVALIDARG;
return ISC_FALSE;
}
if (*rvalp == ISC_R_SUCCESS)
return ISC_FALSE;
/* No possible action in any case... */
......@@ -1990,13 +1984,20 @@ dhc6_init_action(struct client_state *client, isc_result_t rval,
* packet should be ignored), or false if no action was taken.
*/
static isc_boolean_t
dhc6_select_action(struct client_state *client, isc_result_t rval,
dhc6_select_action(struct client_state *client, isc_result_t *rvalp,
unsigned code)
{
struct dhc6_lease *lease;
isc_result_t rval;
if (client == NULL)
return ISC_R_INVALIDARG;
if (rvalp == NULL)
log_fatal("Impossible condition at %s:%d.", MDL);
if (client == NULL) {
*rvalp = ISC_R_INVALIDARG;
return ISC_FALSE;
}
rval = *rvalp;
if (rval == ISC_R_SUCCESS)
return ISC_FALSE;
......@@ -2110,12 +2111,19 @@ dhc6_withdraw_lease(struct client_state *client)
* packet should be ignored), or false if no action was taken.
*/
static isc_boolean_t
dhc6_reply_action(struct client_state *client, isc_result_t rval,
dhc6_reply_action(struct client_state *client, isc_result_t *rvalp,
unsigned code)
{
isc_result_t rval;
if (client == NULL)
return ISC_R_INVALIDARG;
if (rvalp == NULL)
log_fatal("Impossible condition at %s:%d.", MDL);
if (client == NULL) {
*rvalp = ISC_R_INVALIDARG;
return ISC_FALSE;
}
rval = *rvalp;
if (rval == ISC_R_SUCCESS)
return ISC_FALSE;
......@@ -2142,7 +2150,7 @@ dhc6_reply_action(struct client_state *client, isc_result_t rval,
* sooner than the current interval, but for now we don't.)
*/
case STATUS_UseMulticast:
if(client->active_lease != NULL)
if (client->active_lease != NULL)
delete_option(&dhcp_universe,
client->active_lease->options,
D6O_UNICAST);
......@@ -2168,7 +2176,7 @@ dhc6_reply_action(struct client_state *client, isc_result_t rval,
* to init, redo server selection and get new addresses.
*/
dhc6_withdraw_lease(client);
return ISC_TRUE;
break;
/* "If the status code is NoAddrsAvail, the client has
* received no usable addresses in the IA and may choose
......@@ -2197,13 +2205,78 @@ dhc6_reply_action(struct client_state *client, isc_result_t rval,
return ISC_TRUE;
}
/* status code <-> action matrix for the client in STOPPED state
* (release/decline). Returns true if action was taken (and the
* packet should be ignored), or false if no action was taken.
* NoBinding is translated into Success.
*/
static isc_boolean_t
dhc6_stop_action(struct client_state *client, isc_result_t *rvalp,
unsigned code)
{
isc_result_t rval;
if (rvalp == NULL)
log_fatal("Impossible condition at %s:%d.", MDL);
if (client == NULL) {
*rvalp = ISC_R_INVALIDARG;
return ISC_FALSE;
}
rval = *rvalp;
if (rval == ISC_R_SUCCESS)
return ISC_FALSE;
switch (code) {
/* It's possible an earlier status code set rval to a failure
* code, and we've encountered a later success.
*/
case STATUS_Success:
/* For unknown codes...it's a soft (retryable) error. */
case STATUS_UnspecFail:
default:
return ISC_FALSE;
/* NoBinding is not an error */
case STATUS_NoBinding:
if (rval == ISC_R_FAILURE)
*rvalp = ISC_R_SUCCESS;
return ISC_FALSE;
/* Should not happen */
case STATUS_NoAddrsAvail:
break;
/* Give up on it */
case STATUS_NotOnLink:
break;
/* The server is telling us to use a multicast address, so
* we have to delete the unicast option from the active
* lease, then allow retransmission to occur normally.
* (XXX: It might be preferable in this case to retransmit
* sooner than the current interval, but for now we don't.)
*/
case STATUS_UseMulticast:
if (client->active_lease != NULL)
delete_option(&dhcp_universe,
client->active_lease->options,
D6O_UNICAST);
return ISC_FALSE;
}
return ISC_TRUE;
}
/* Look at a new and old lease, and make sure the new information is not
* losing us any state.
*/
static isc_result_t
dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
{
isc_boolean_t (*action)(struct client_state *, isc_result_t, unsigned);
isc_boolean_t (*action)(struct client_state *,
isc_result_t *, unsigned);
struct dhc6_ia *ia;
struct dhc6_addr *addr;
isc_result_t rval = ISC_R_SUCCESS;
......@@ -2229,6 +2302,10 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
action = dhc6_reply_action;
break;
case S_STOPPED:
action = dhc6_stop_action;
break;
default:
log_fatal("Impossible condition at %s:%d.", MDL);
return ISC_R_CANCELED;
......@@ -2239,7 +2316,7 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
* and do not continue.
*/
rval = dhc6_check_status(rval, new->options, "message", &code);
if (action(client, rval, code))
if (action(client, &rval, code))
return ISC_R_CANCELED;
for (ia = new->bindings ; ia != NULL ; ia = ia->next) {
......@@ -2257,7 +2334,7 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
}
rval = dhc6_check_status(rval, ia->options,
scope, &code);
if (action(client, rval, code))
if (action(client, &rval, code))
return ISC_R_CANCELED;
for (addr = ia->addrs ; addr != NULL ;
......@@ -2268,7 +2345,7 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
scope = "IAPREFIX";
rval = dhc6_check_status(rval, addr->options,
scope, &code);
if (action(client, rval, code))
if (action(client, &rval, code))
return ISC_R_CANCELED;
}
}
......@@ -2324,6 +2401,10 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
*/
break;
case S_STOPPED:
/* Nothing critical to do at this stage. */
break;
default:
log_fatal("REALLY impossible condition at %s:%d.", MDL);
return ISC_R_CANCELED;
......@@ -2824,6 +2905,7 @@ dhc6_add_ia_na(struct client_state *client, struct data_string *packet,
case DHCPV6_CONFIRM:
case DHCPV6_RELEASE:
case DHCPV6_DECLINE:
/* Set t1 and t2 to zero; server will ignore them */
memset(iads.buffer->data + 4, 0, 8);
log_debug("XMT: X-- IA_NA %s",
......@@ -2900,6 +2982,13 @@ dhc6_add_ia_na(struct client_state *client, struct data_string *packet,
piaddr(addr->address));
break;
case DHCPV6_DECLINE:
/* Preferred and max life are irrelevant */
memset(addrds.buffer->data + 16, 0, 8);
log_debug("XMT: | X-- Decline Address %s",
piaddr(addr->address));
break;
default:
log_fatal("Impossible condition at %s:%d.",
MDL);
......@@ -2929,6 +3018,25 @@ dhc6_add_ia_na(struct client_state *client, struct data_string *packet,
return rval;
}
/* stopping_finished() checks if there is a remaining work to do.
*/
static isc_boolean_t
stopping_finished(void)
{
struct interface_info *ip;
struct client_state *client;
for (ip = interfaces; ip; ip = ip -> next) {
for (client = ip -> client; client; client = client -> next) {
if (client->state != S_STOPPED)
return ISC_FALSE;
if (client->active_lease != NULL)
return ISC_FALSE;
}
}
return ISC_TRUE;
}
/* reply_handler() accepts a Reply while we're attempting Select or Renew or
* Rebind. Basically any Reply packet.
*/
......@@ -2974,6 +3082,19 @@ reply_handler(struct packet *packet, struct client_state *client)
cancel_timeout(do_refresh6, client);
cancel_timeout(do_release6, client);
/* If this is in response to a Release/Decline, clean up and return. */
if (client->state == S_STOPPED) {
if (client->active_lease == NULL)
return;
dhc6_lease_destroy(&client->active_lease, MDL);
client->active_lease = NULL;
/* We should never wait for nothing!? */
if (stopping_finished())
exit(0);
return;
}
/* Action was taken, so now that we've torn down our scheduled
* retransmissions, return.
*/
......@@ -2985,16 +3106,6 @@ reply_handler(struct packet *packet, struct client_state *client)
client->selected_lease = NULL;
}
/* If this is in response to a Release, clean up and return. */
if (client->state == S_STOPPED) {
if (client->active_lease == NULL)
log_fatal("Impossible condition at %s:%d.", MDL);
dhc6_lease_destroy(&client->active_lease, MDL);
client->active_lease = NULL;
return;
}
/* If this is in response to a confirm, we use the lease we've
* already got, not the reply we were sent.
*/
......
......@@ -506,8 +506,19 @@ main(int argc, char **argv) {
}
}
if (release_mode || exit_mode)
if (exit_mode)
return 0;
if (release_mode) {
#ifndef DHCPv6
return 0;
#else
if (local_family == AF_INET6) {
if (onetry)
return 0;
} else
return 0;
#endif /* DHCPv6 */
}
/* Start up a listener for the object management API protocol. */
if (top_level_config.omapi_port != -1) {
......
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