diff --git a/net/tipc/link.c b/net/tipc/link.c index 065e9e67da5d..df763be38541 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -128,8 +128,8 @@ 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; @@ -138,6 +138,7 @@ struct tipc_link { u32 abort_limit; u32 state; u16 peer_caps; + bool in_session; bool active; u32 silent_intv_cnt; char if_name[TIPC_MAX_IF_NAME]; @@ -216,11 +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 { @@ -478,7 +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; @@ -847,7 +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); @@ -1455,6 +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 @@ -1488,17 +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) @@ -1526,16 +1555,13 @@ 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: - - if (l->peer_caps & TIPC_LINK_PROTO_SEQNO && - less(msg_seqno(hdr), l->rcv_nxt_state)) - break; l->rcv_nxt_state = msg_seqno(hdr) + 1; /* Update own tolerance if peer indicates a non-zero value */ diff --git a/net/tipc/link.h b/net/tipc/link.h index d56f9c9e5000..7bc494a33fdf 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -111,6 +111,7 @@ 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); diff --git a/net/tipc/node.c b/net/tipc/node.c index 1cdb176798f7..52fd80b0e728 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -1540,7 +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) @@ -1574,6 +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))