Commit 0e97c4fb authored by David S. Miller's avatar David S. Miller

Merge branch 'tipc-make-link-protocol-more-resilient'

Jon Maloy says:

====================
tipc: make link protocol more resilient

These two commits make the link ptotocol more resilient to
infrastructures with frequent packet duplication and long delays.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents e32f55f3 7ea817f4
......@@ -128,14 +128,17 @@ struct tipc_link {
struct net *net;
/* Management and link supervision data */
u32 peer_session;
u32 session;
u16 peer_session;
u16 session;
u16 snd_nxt_state;
u16 rcv_nxt_state;
u32 peer_bearer_id;
u32 bearer_id;
u32 tolerance;
u32 abort_limit;
u32 state;
u16 peer_caps;
bool in_session;
bool active;
u32 silent_intv_cnt;
char if_name[TIPC_MAX_IF_NAME];
......@@ -214,11 +217,6 @@ enum {
*/
#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
/* Wildcard value for link session numbers. When it is known that
* peer endpoint is down, any session number must be accepted.
*/
#define ANY_SESSION 0x10000
/* Link FSM states:
*/
enum {
......@@ -339,6 +337,11 @@ char tipc_link_plane(struct tipc_link *l)
return l->net_plane;
}
void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
{
l->peer_caps = capabilities;
}
void tipc_link_add_bc_peer(struct tipc_link *snd_l,
struct tipc_link *uc_l,
struct sk_buff_head *xmitq)
......@@ -471,7 +474,7 @@ bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
l->addr = peer;
l->peer_caps = peer_caps;
l->net = net;
l->peer_session = ANY_SESSION;
l->in_session = false;
l->bearer_id = bearer_id;
l->tolerance = tolerance;
l->net_plane = net_plane;
......@@ -840,7 +843,7 @@ void link_prepare_wakeup(struct tipc_link *l)
void tipc_link_reset(struct tipc_link *l)
{
l->peer_session = ANY_SESSION;
l->in_session = false;
l->session++;
l->mtu = l->advertised_mtu;
__skb_queue_purge(&l->transmq);
......@@ -859,6 +862,8 @@ void tipc_link_reset(struct tipc_link *l)
l->rcv_unacked = 0;
l->snd_nxt = 1;
l->rcv_nxt = 1;
l->snd_nxt_state = 1;
l->rcv_nxt_state = 1;
l->acked = 0;
l->silent_intv_cnt = 0;
l->rst_cnt = 0;
......@@ -1353,6 +1358,8 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
if (mtyp == STATE_MSG) {
if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
msg_set_seqno(hdr, l->snd_nxt_state++);
msg_set_seq_gap(hdr, rcvgap);
msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
msg_set_probe(hdr, probe);
......@@ -1444,6 +1451,44 @@ void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
}
}
/* tipc_link_validate_msg(): validate message against current link state
* Returns true if message should be accepted, otherwise false
*/
bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
{
u16 curr_session = l->peer_session;
u16 session = msg_session(hdr);
int mtyp = msg_type(hdr);
if (msg_user(hdr) != LINK_PROTOCOL)
return true;
switch (mtyp) {
case RESET_MSG:
if (!l->in_session)
return true;
/* Accept only RESET with new session number */
return more(session, curr_session);
case ACTIVATE_MSG:
if (!l->in_session)
return true;
/* Accept only ACTIVATE with new or current session number */
return !less(session, curr_session);
case STATE_MSG:
/* Accept only STATE with current session number */
if (!l->in_session)
return false;
if (session != curr_session)
return false;
if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
return true;
/* Accept only STATE with new sequence number */
return !less(msg_seqno(hdr), l->rcv_nxt_state);
default:
return false;
}
}
/* tipc_link_proto_rcv(): receive link level protocol message :
* Note that network plane id propagates through the network, and may
* change at any time. The node with lowest numerical id determines
......@@ -1477,17 +1522,12 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
hdr = buf_msg(skb);
data = msg_data(hdr);
if (!tipc_link_validate_msg(l, hdr))
goto exit;
switch (mtyp) {
case RESET_MSG:
/* Ignore duplicate RESET with old session number */
if ((less_eq(msg_session(hdr), l->peer_session)) &&
(l->peer_session != ANY_SESSION))
break;
/* fall thru' */
case ACTIVATE_MSG:
/* Complete own link name with peer's interface name */
if_name = strrchr(l->name, ':') + 1;
if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
......@@ -1515,12 +1555,14 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
rc = TIPC_LINK_UP_EVT;
l->peer_session = msg_session(hdr);
l->in_session = true;
l->peer_bearer_id = msg_bearer_id(hdr);
if (l->mtu > msg_max_pkt(hdr))
l->mtu = msg_max_pkt(hdr);
break;
case STATE_MSG:
l->rcv_nxt_state = msg_seqno(hdr) + 1;
/* Update own tolerance if peer indicates a non-zero value */
if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
......
......@@ -110,6 +110,8 @@ char *tipc_link_name(struct tipc_link *l);
char tipc_link_plane(struct tipc_link *l);
int tipc_link_prio(struct tipc_link *l);
int tipc_link_window(struct tipc_link *l);
void tipc_link_update_caps(struct tipc_link *l, u16 capabilities);
bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr);
unsigned long tipc_link_tolerance(struct tipc_link *l);
void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
struct sk_buff_head *xmitq);
......
......@@ -363,6 +363,8 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_node *n, *temp_node;
struct tipc_link *l;
int bearer_id;
int i;
spin_lock_bh(&tn->node_list_lock);
......@@ -370,6 +372,11 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
if (n) {
/* Same node may come back with new capabilities */
n->capabilities = capabilities;
for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
l = n->links[bearer_id].link;
if (l)
tipc_link_update_caps(l, capabilities);
}
goto exit;
}
n = kzalloc(sizeof(*n), GFP_ATOMIC);
......@@ -1533,7 +1540,7 @@ static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id
* tipc_node_check_state - check and if necessary update node state
* @skb: TIPC packet
* @bearer_id: identity of bearer delivering the packet
* Returns true if state is ok, otherwise consumes buffer and returns false
* Returns true if state and msg are ok, otherwise false
*/
static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
int bearer_id, struct sk_buff_head *xmitq)
......@@ -1567,6 +1574,9 @@ static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
}
}
if (!tipc_link_validate_msg(l, hdr))
return false;
/* Check and update node accesibility if applicable */
if (state == SELF_UP_PEER_COMING) {
if (!tipc_link_is_up(l))
......
......@@ -49,14 +49,16 @@ enum {
TIPC_BCAST_STATE_NACK = (1 << 2),
TIPC_BLOCK_FLOWCTL = (1 << 3),
TIPC_BCAST_RCAST = (1 << 4),
TIPC_NODE_ID128 = (1 << 5)
TIPC_NODE_ID128 = (1 << 5),
TIPC_LINK_PROTO_SEQNO = (1 << 6)
};
#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \
TIPC_BCAST_STATE_NACK | \
TIPC_BCAST_RCAST | \
TIPC_BLOCK_FLOWCTL | \
TIPC_NODE_ID128)
#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \
TIPC_BCAST_STATE_NACK | \
TIPC_BCAST_RCAST | \
TIPC_BLOCK_FLOWCTL | \
TIPC_NODE_ID128 | \
TIPC_LINK_PROTO_SEQNO)
#define INVALID_BEARER_ID -1
void tipc_node_stop(struct net *net);
......
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