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tipc: merge link->exec_mode and link->state into one FSM

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Until now, we have been handling link failover and synchronization
by using an additional link state variable, "exec_mode". This variable
is not independent of the link FSM state, something causing a risk of
inconsistencies, apart from the fact that it clutters the code.

The conditions are now in place to define a new link FSM that covers
all existing use cases, including failover and synchronization, and
eliminate the "exec_mode" field altogether. The FSM must also support
non-atomic resetting of links, which will be introduced later.

The new link FSM is shown below, with 7 states and 8 events.
Only events leading to state change are shown as edges.

+------------------------------------+
|RESET_EVT                           |
|                                    |
|                             +--------------+
|           +-----------------|   SYNCHING   |-----------------+
|           |FAILURE_EVT      +--------------+   PEER_RESET_EVT|
|           |                  A            |                  |
|           |                  |            |                  |
|           |                  |            |                  |
|           |                  |SYNCH_      |SYNCH_            |
|           |                  |BEGIN_EVT   |END_EVT           |
|           |                  |            |                  |
|           V                  |            V                  V
|    +-------------+          +--------------+          +------------+
|    |  RESETTING  |<---------|  ESTABLISHED |--------->| PEER_RESET |
|    +-------------+ FAILURE_ +--------------+ PEER_    +------------+
|           |        EVT        |    A         RESET_EVT       |
|           |                   |    |                         |
|           |                   |    |                         |
|           |    +--------------+    |                         |
|  RESET_EVT|    |RESET_EVT          |ESTABLISH_EVT            |
|           |    |                   |                         |
|           |    |                   |                         |
|           V    V                   |                         |
|    +-------------+          +--------------+        RESET_EVT|
+--->|    RESET    |--------->| ESTABLISHING |<----------------+
     +-------------+ PEER_    +--------------+
      |           A  RESET_EVT       |
      |           |                  |
      |           |                  |
      |FAILOVER_  |FAILOVER_         |FAILOVER_
      |BEGIN_EVT  |END_EVT           |BEGIN_EVT
      |           |                  |
      V           |                  |
     +-------------+                 |
     | FAILINGOVER |<----------------+
     +-------------+

These changes are fully backwards compatible.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jon Paul Maloy 2015-07-30 18:24:21 -04:00 committed by David S. Miller
parent 5045f7b900
commit 662921cd0a
3 changed files with 231 additions and 185 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

360
net/tipc/link.c
View File

@ -50,7 +50,6 @@
*/
static const char *link_co_err = "Link tunneling error, ";
static const char *link_rst_msg = "Resetting link ";
static const char *link_unk_evt = "Unknown link event ";
static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
[TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC },
@ -85,46 +84,23 @@ static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
*/
#define WILDCARD_SESSION 0x10000
/* State value stored in 'failover_pkts'
*/
#define FIRST_FAILOVER 0xffffu
/* Link FSM states and events:
/* Link FSM states:
*/
enum {
TIPC_LINK_WORKING,
TIPC_LINK_PROBING,
TIPC_LINK_RESETTING,
TIPC_LINK_ESTABLISHING
};
enum {
PEER_RESET_EVT = RESET_MSG,
ACTIVATE_EVT = ACTIVATE_MSG,
TRAFFIC_EVT, /* Any other valid msg from peer */
SILENCE_EVT /* Peer was silent during last timer interval*/
LINK_ESTABLISHED = 0xe,
LINK_ESTABLISHING = 0xe << 4,
LINK_RESET = 0x1 << 8,
LINK_RESETTING = 0x2 << 12,
LINK_PEER_RESET = 0xd << 16,
LINK_FAILINGOVER = 0xf << 20,
LINK_SYNCHING = 0xc << 24
};
/* Link FSM state checking routines
*/
static int link_working(struct tipc_link *l)
static int link_is_up(struct tipc_link *l)
{
return l->state == TIPC_LINK_WORKING;
}
static int link_probing(struct tipc_link *l)
{
return l->state == TIPC_LINK_PROBING;
}
static int link_resetting(struct tipc_link *l)
{
return l->state == TIPC_LINK_RESETTING;
}
static int link_establishing(struct tipc_link *l)
{
return l->state == TIPC_LINK_ESTABLISHING;
return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
}
static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
@ -141,11 +117,29 @@ static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
/*
* Simple non-static link routines (i.e. referenced outside this file)
*/
int tipc_link_is_up(struct tipc_link *l_ptr)
bool tipc_link_is_up(struct tipc_link *l)
{
if (!l_ptr)
return 0;
return link_working(l_ptr) || link_probing(l_ptr);
return link_is_up(l);
}
bool tipc_link_is_reset(struct tipc_link *l)
{
return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
}
bool tipc_link_is_synching(struct tipc_link *l)
{
return l->state == LINK_SYNCHING;
}
bool tipc_link_is_failingover(struct tipc_link *l)
{
return l->state == LINK_FAILINGOVER;
}
bool tipc_link_is_blocked(struct tipc_link *l)
{
return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
}
int tipc_link_is_active(struct tipc_link *l)
@ -210,7 +204,7 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
l_ptr->tolerance = b_ptr->tolerance;
l_ptr->snd_nxt = 1;
l_ptr->rcv_nxt = 1;
l_ptr->state = TIPC_LINK_RESETTING;
l_ptr->state = LINK_RESET;
l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
msg = l_ptr->pmsg;
@ -265,120 +259,159 @@ void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
* tipc_link_fsm_evt - link finite state machine
* @l: pointer to link
* @evt: state machine event to be processed
* @xmitq: queue to prepend created protocol message, if any
*/
static int tipc_link_fsm_evt(struct tipc_link *l, int evt,
struct sk_buff_head *xmitq)
int tipc_link_fsm_evt(struct tipc_link *l, int evt)
{
int rc = 0;
struct tipc_link *pl;
enum {
LINK_RESET = 1,
LINK_ACTIVATE = (1 << 1),
SND_PROBE = (1 << 2),
SND_STATE = (1 << 3),
SND_RESET = (1 << 4),
SND_ACTIVATE = (1 << 5),
SND_BCAST_SYNC = (1 << 6)
} actions = 0;
if (l->exec_mode == TIPC_LINK_BLOCKED)
return rc;
switch (l->state) {
case TIPC_LINK_WORKING:
case LINK_RESETTING:
switch (evt) {
case TRAFFIC_EVT:
case ACTIVATE_EVT:
case LINK_PEER_RESET_EVT:
l->state = LINK_PEER_RESET;
break;
case SILENCE_EVT:
l->state = TIPC_LINK_PROBING;
actions |= SND_PROBE;
break;
case PEER_RESET_EVT:
actions |= LINK_RESET | SND_ACTIVATE;
case LINK_RESET_EVT:
l->state = LINK_RESET;
break;
case LINK_FAILURE_EVT:
case LINK_FAILOVER_BEGIN_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILOVER_END_EVT:
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
default:
pr_debug("%s%u WORKING\n", link_unk_evt, evt);
goto illegal_evt;
}
break;
case TIPC_LINK_PROBING:
case LINK_RESET:
switch (evt) {
case TRAFFIC_EVT:
case ACTIVATE_EVT:
l->state = TIPC_LINK_WORKING;
case LINK_PEER_RESET_EVT:
l->state = LINK_ESTABLISHING;
break;
case PEER_RESET_EVT:
actions |= LINK_RESET | SND_ACTIVATE;
break;
case SILENCE_EVT:
if (l->silent_intv_cnt <= l->abort_limit) {
actions |= SND_PROBE;
break;
}
actions |= LINK_RESET | SND_RESET;
case LINK_FAILOVER_BEGIN_EVT:
l->state = LINK_FAILINGOVER;
case LINK_FAILURE_EVT:
case LINK_RESET_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILOVER_END_EVT:
break;
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
default:
pr_err("%s%u PROBING\n", link_unk_evt, evt);
goto illegal_evt;
}
break;
case TIPC_LINK_RESETTING:
case LINK_PEER_RESET:
switch (evt) {
case TRAFFIC_EVT:
case LINK_RESET_EVT:
l->state = LINK_ESTABLISHING;
break;
case ACTIVATE_EVT:
pl = node_active_link(l->owner, 0);
if (pl && link_probing(pl))
break;
l->state = TIPC_LINK_WORKING;
actions |= LINK_ACTIVATE;
if (!l->owner->working_links)
actions |= SND_BCAST_SYNC;
break;
case PEER_RESET_EVT:
l->state = TIPC_LINK_ESTABLISHING;
actions |= SND_ACTIVATE;
break;
case SILENCE_EVT:
actions |= SND_RESET;
case LINK_PEER_RESET_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILURE_EVT:
break;
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:
pr_err("%s%u in RESETTING\n", link_unk_evt, evt);
goto illegal_evt;
}
break;
case TIPC_LINK_ESTABLISHING:
case LINK_FAILINGOVER:
switch (evt) {
case TRAFFIC_EVT:
case ACTIVATE_EVT:
pl = node_active_link(l->owner, 0);
if (pl && link_probing(pl))
break;
l->state = TIPC_LINK_WORKING;
actions |= LINK_ACTIVATE;
if (!l->owner->working_links)
actions |= SND_BCAST_SYNC;
case LINK_FAILOVER_END_EVT:
l->state = LINK_RESET;
break;
case PEER_RESET_EVT:
break;
case SILENCE_EVT:
actions |= SND_ACTIVATE;
case LINK_PEER_RESET_EVT:
case LINK_RESET_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILURE_EVT:
break;
case LINK_FAILOVER_BEGIN_EVT:
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
default:
pr_err("%s%u ESTABLISHING\n", link_unk_evt, evt);
goto illegal_evt;
}
break;
case LINK_ESTABLISHING:
switch (evt) {
case LINK_ESTABLISH_EVT:
l->state = LINK_ESTABLISHED;
rc |= TIPC_LINK_UP_EVT;
break;
case LINK_FAILOVER_BEGIN_EVT:
l->state = LINK_FAILINGOVER;
break;
case LINK_PEER_RESET_EVT:
case LINK_RESET_EVT:
case LINK_FAILURE_EVT:
case LINK_SYNCH_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
break;
case LINK_SYNCH_END_EVT:
default:
goto illegal_evt;
}
break;
case LINK_ESTABLISHED:
switch (evt) {
case LINK_PEER_RESET_EVT:
l->state = LINK_PEER_RESET;
rc |= TIPC_LINK_DOWN_EVT;
break;
case LINK_FAILURE_EVT:
l->state = LINK_RESETTING;
rc |= TIPC_LINK_DOWN_EVT;
break;
case LINK_RESET_EVT:
l->state = LINK_RESET;
break;
case LINK_ESTABLISH_EVT:
break;
case LINK_SYNCH_BEGIN_EVT:
l->state = LINK_SYNCHING;
break;
case LINK_SYNCH_END_EVT:
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case LINK_SYNCHING:
switch (evt) {
case LINK_PEER_RESET_EVT:
l->state = LINK_PEER_RESET;
rc |= TIPC_LINK_DOWN_EVT;
break;
case LINK_FAILURE_EVT:
l->state = LINK_RESETTING;
rc |= TIPC_LINK_DOWN_EVT;
break;
case LINK_RESET_EVT:
l->state = LINK_RESET;
break;
case LINK_ESTABLISH_EVT:
case LINK_SYNCH_BEGIN_EVT:
break;
case LINK_SYNCH_END_EVT:
l->state = LINK_ESTABLISHED;
break;
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
default:
pr_err("Unknown link state %u/%u\n", l->state, evt);
pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
}
/* Perform actions as decided by FSM */
if (actions & LINK_RESET) {
l->exec_mode = TIPC_LINK_BLOCKED;
rc = TIPC_LINK_DOWN_EVT;
}
if (actions & LINK_ACTIVATE)
rc = TIPC_LINK_UP_EVT;
return rc;
illegal_evt:
pr_err("Illegal FSM event %x in state %x on link %s\n",
evt, l->state, l->name);
return rc;
}
@ -432,12 +465,11 @@ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
bool xmit = false;
bool prb = false;
if (l->exec_mode == TIPC_LINK_BLOCKED)
return rc;
link_profile_stats(l);
if (l->state == TIPC_LINK_WORKING) {
switch (l->state) {
case LINK_ESTABLISHED:
case LINK_SYNCHING:
if (!l->silent_intv_cnt) {
if (tipc_bclink_acks_missing(l->owner))
xmit = true;
@ -445,17 +477,26 @@ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
xmit = true;
prb = true;
} else {
l->exec_mode = TIPC_LINK_BLOCKED;
rc |= TIPC_LINK_DOWN_EVT;
rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
}
l->silent_intv_cnt++;
} else if (l->state == TIPC_LINK_RESETTING) {
break;
case LINK_RESET:
xmit = true;
mtyp = RESET_MSG;
} else if (l->state == TIPC_LINK_ESTABLISHING) {
break;
case LINK_ESTABLISHING:
xmit = true;
mtyp = ACTIVATE_MSG;
break;
case LINK_RESETTING:
case LINK_PEER_RESET:
case LINK_FAILINGOVER:
break;
default:
break;
}
if (xmit)
tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
@ -559,7 +600,7 @@ void tipc_link_reset(struct tipc_link *l)
{
struct tipc_node *owner = l->owner;
l->state = TIPC_LINK_RESETTING;
tipc_link_fsm_evt(l, LINK_RESET_EVT);
/* Link is down, accept any session */
l->peer_session = WILDCARD_SESSION;
@ -902,8 +943,7 @@ static int tipc_link_retransm(struct tipc_link *l, int retransm,
l->stale_count = 1;
} else if (++l->stale_count > 100) {
link_retransmit_failure(l, skb);
l->exec_mode = TIPC_LINK_BLOCKED;
return TIPC_LINK_DOWN_EVT;
return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
}
skb_queue_walk(&l->transmq, skb) {
if (!retransm)
@ -1002,25 +1042,23 @@ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb)
l->stats.recv_bundled += msg_msgcnt(hdr);
while (tipc_msg_extract(skb, &iskb, &pos))
tipc_data_input(l, iskb);
return rc;
return 0;
} else if (usr == MSG_FRAGMENTER) {
l->stats.recv_fragments++;
if (tipc_buf_append(reasm_skb, &skb)) {
l->stats.recv_fragmented++;
tipc_data_input(l, skb);
} else if (!*reasm_skb) {
l->exec_mode = TIPC_LINK_BLOCKED;
l->state = TIPC_LINK_RESETTING;
rc = TIPC_LINK_DOWN_EVT;
return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
}
return rc;
return 0;
} else if (usr == BCAST_PROTOCOL) {
tipc_link_sync_rcv(node, skb);
return rc;
return 0;
}
drop:
kfree_skb(skb);
return rc;
return 0;
}
static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
@ -1068,9 +1106,9 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
continue;
}
if (unlikely(!link_working(l))) {
rc = tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
if (!link_working(l)) {
if (unlikely(!link_is_up(l))) {
rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
if (!link_is_up(l)) {
kfree_skb(__skb_dequeue(arrvq));
return rc;
}
@ -1192,7 +1230,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
int node_up = l->owner->bclink.recv_permitted;
/* Don't send protocol message during reset or link failover */
if (l->exec_mode == TIPC_LINK_BLOCKED)
if (tipc_link_is_blocked(l))
return;
msg_set_type(hdr, mtyp);
@ -1302,7 +1340,6 @@ tnl:
tnl->drop_point = l->rcv_nxt;
tnl->failover_reasm_skb = l->reasm_buf;
l->reasm_buf = NULL;
l->exec_mode = TIPC_LINK_BLOCKED;
}
}
@ -1323,7 +1360,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
char *if_name;
int rc = 0;
if (l->exec_mode == TIPC_LINK_BLOCKED)
if (tipc_link_is_blocked(l))
goto exit;
if (link_own_addr(l) > msg_prevnode(hdr))
@ -1337,6 +1374,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
(l->peer_session != WILDCARD_SESSION))
break;
/* fall thru' */
case ACTIVATE_MSG:
/* Complete own link name with peer's interface name */
@ -1355,13 +1393,20 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
l->priority = peers_prio;
if (msg_type(hdr) == RESET_MSG) {
rc |= tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
} else if (!link_is_up(l)) {
tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
rc |= tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
}
l->peer_session = msg_session(hdr);
l->peer_bearer_id = msg_bearer_id(hdr);
rc = tipc_link_fsm_evt(l, msg_type(hdr), xmitq);
if (l->mtu > msg_max_pkt(hdr))
l->mtu = msg_max_pkt(hdr);
break;
case STATE_MSG:
/* Update own tolerance if peer indicates a non-zero value */
if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
l->tolerance = peers_tol;
@ -1370,11 +1415,11 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
l->stats.recv_states++;
if (msg_probe(hdr))
l->stats.recv_probes++;
rc = tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
if (!tipc_link_is_up(l))
rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
if (!link_is_up(l))
break;
/* Has peer sent packets we haven't received yet ? */
/* Send NACK if peer has sent pkts we haven't received yet */
if (more(peers_snd_nxt, l->rcv_nxt))
rcvgap = peers_snd_nxt - l->rcv_nxt;
if (rcvgap || (msg_probe(hdr)))
@ -1387,6 +1432,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
rc = tipc_link_retransm(l, nacked_gap, xmitq);
l->stats.recv_nacks++;
}
tipc_link_advance_backlog(l, xmitq);
if (unlikely(!skb_queue_empty(&l->wakeupq)))
link_prepare_wakeup(l);
@ -1463,19 +1509,7 @@ static void link_print(struct tipc_link *l, const char *str)
u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt;
u16 tail = l->snd_nxt - 1;
pr_info("%s Link <%s>:", str, l->name);
if (link_probing(l))
pr_cont(":P\n");
else if (link_establishing(l))
pr_cont(":E\n");
else if (link_resetting(l))
pr_cont(":R\n");
else if (link_working(l))
pr_cont(":W\n");
else
pr_cont("\n");
pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
skb_queue_len(&l->transmq), head, tail,
skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);

25
net/tipc/link.h
View File

@ -49,13 +49,17 @@
*/
#define INVALID_LINK_SEQ 0x10000
/* Link endpoint receive states
/* Link FSM events:
*/
enum {
TIPC_LINK_OPEN,
TIPC_LINK_BLOCKED,
TIPC_LINK_TUNNEL
LINK_ESTABLISH_EVT = 0xec1ab1e,
LINK_PEER_RESET_EVT = 0x9eed0e,
LINK_FAILURE_EVT = 0xfa110e,
LINK_RESET_EVT = 0x10ca1d0e,
LINK_FAILOVER_BEGIN_EVT = 0xfa110bee,
LINK_FAILOVER_END_EVT = 0xfa110ede,
LINK_SYNCH_BEGIN_EVT = 0xc1ccbee,
LINK_SYNCH_END_EVT = 0xc1ccede
};
/* Events returned from link at packet reception or at timeout
@ -120,7 +124,6 @@ struct tipc_stats {
* @pmsg: convenience pointer to "proto_msg" field
* @priority: current link priority
* @net_plane: current link network plane ('A' through 'H')
* @exec_mode: transmit/receive mode for link endpoint instance
* @backlog_limit: backlog queue congestion thresholds (indexed by importance)
* @exp_msg_count: # of tunnelled messages expected during link changeover
* @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
@ -155,7 +158,7 @@ struct tipc_link {
u32 tolerance;
unsigned long keepalive_intv;
u32 abort_limit;
int state;
u32 state;
u32 silent_intv_cnt;
struct {
unchar hdr[INT_H_SIZE];
@ -166,7 +169,6 @@ struct tipc_link {
char net_plane;
/* Failover/synch */
u8 exec_mode;
u16 drop_point;
struct sk_buff *failover_reasm_skb;
@ -214,8 +216,13 @@ void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
int mtyp, struct sk_buff_head *xmitq);
void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
struct sk_buff_head *xmitq);
int tipc_link_fsm_evt(struct tipc_link *l, int evt);
void tipc_link_reset_fragments(struct tipc_link *l_ptr);
int tipc_link_is_up(struct tipc_link *l_ptr);
bool tipc_link_is_up(struct tipc_link *l);
bool tipc_link_is_reset(struct tipc_link *l);
bool tipc_link_is_synching(struct tipc_link *l);
bool tipc_link_is_failingover(struct tipc_link *l);
bool tipc_link_is_blocked(struct tipc_link *l);
int tipc_link_is_active(struct tipc_link *l_ptr);
void tipc_link_purge_queues(struct tipc_link *l_ptr);
void tipc_link_purge_backlog(struct tipc_link *l);

31
net/tipc/node.c
View File

@ -334,7 +334,6 @@ static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
if (!ol) {
*slot0 = bearer_id;
*slot1 = bearer_id;
nl->exec_mode = TIPC_LINK_OPEN;
tipc_link_build_bcast_sync_msg(nl, xmitq);
node_established_contact(n);
return;
@ -368,7 +367,7 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id)
struct sk_buff_head xmitq;
l = n->links[bearer_id].link;
if (!l || !tipc_link_is_up(l))
if (!l || tipc_link_is_reset(l))
return;
__skb_queue_head_init(&xmitq);
@ -414,6 +413,7 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id)
n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, &xmitq);
tipc_link_reset(l);
tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
tipc_bearer_xmit(n->net, tnl->bearer_id, &xmitq, maddr);
}
@ -749,7 +749,7 @@ static void node_lost_contact(struct tipc_node *n_ptr)
struct tipc_link *l_ptr = n_ptr->links[i].link;
if (!l_ptr)
continue;
l_ptr->exec_mode = TIPC_LINK_OPEN;
tipc_link_fsm_evt(l_ptr, LINK_FAILOVER_END_EVT);
kfree_skb(l_ptr->failover_reasm_skb);
l_ptr->failover_reasm_skb = NULL;
tipc_link_reset_fragments(l_ptr);
@ -989,7 +989,7 @@ int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
* Returns true if state is ok, otherwise consumes buffer and returns false
*/
static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
int bearer_id)
int bearer_id, struct sk_buff_head *xmitq)
{
struct tipc_msg *hdr = buf_msg(skb);
int usr = msg_user(hdr);
@ -1042,42 +1042,47 @@ static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
/* Initiate or update failover mode if applicable */
if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
syncpt = oseqno + exp_pkts - 1;
if (pl && tipc_link_is_up(pl)) {
if (pl && tipc_link_is_up(pl))
tipc_node_link_down(n, pl->bearer_id);
pl->exec_mode = TIPC_LINK_BLOCKED;
}
/* If pkts arrive out of order, use lowest calculated syncpt */
if (less(syncpt, n->sync_point))
n->sync_point = syncpt;
}
/* Open parallel link when tunnel link reaches synch point */
if ((n->state == NODE_FAILINGOVER) && (more(rcv_nxt, n->sync_point))) {
if ((n->state == NODE_FAILINGOVER) && !tipc_link_is_failingover(l)) {
if (!more(rcv_nxt, n->sync_point))
return true;
tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
if (pl)
pl->exec_mode = TIPC_LINK_OPEN;
tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
return true;
}
/* Initiate or update synch mode if applicable */
if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG)) {
syncpt = iseqno + exp_pkts - 1;
if (!tipc_link_is_up(l)) {
tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
tipc_node_link_up(n, bearer_id, xmitq);
}
if (n->state == SELF_UP_PEER_UP) {
n->sync_point = syncpt;
tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
}
l->exec_mode = TIPC_LINK_TUNNEL;
if (less(syncpt, n->sync_point))
n->sync_point = syncpt;
}
/* Open tunnel link when parallel link reaches synch point */
if ((n->state == NODE_SYNCHING) && (l->exec_mode == TIPC_LINK_TUNNEL)) {
if ((n->state == NODE_SYNCHING) && tipc_link_is_synching(l)) {
if (pl)
dlv_nxt = mod(pl->rcv_nxt - skb_queue_len(pl->inputq));
if (!pl || more(dlv_nxt, n->sync_point)) {
tipc_link_fsm_evt(l, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
l->exec_mode = TIPC_LINK_OPEN;
return true;
}
if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
@ -1143,7 +1148,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
tipc_bclink_acknowledge(n, msg_bcast_ack(hdr));
/* Check and if necessary update node state */
if (likely(tipc_node_check_state(n, skb, bearer_id))) {
if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
rc = tipc_link_rcv(le->link, skb, &xmitq);
skb = NULL;
}