diff --git a/net/tipc/link.c b/net/tipc/link.c index 657ba91fde41..5d2f9198c6bc 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -88,10 +88,10 @@ static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = { /* Link FSM states and events: */ enum { - WORKING_WORKING, - WORKING_UNKNOWN, - RESET_RESET, - RESET_UNKNOWN + TIPC_LINK_WORKING, + TIPC_LINK_PROBING, + TIPC_LINK_RESETTING, + TIPC_LINK_ESTABLISHING }; enum { @@ -103,24 +103,24 @@ enum { /* Link FSM state checking routines */ -static int link_working_working(struct tipc_link *l) +static int link_working(struct tipc_link *l) { - return l->state == WORKING_WORKING; + return l->state == TIPC_LINK_WORKING; } -static int link_working_unknown(struct tipc_link *l) +static int link_probing(struct tipc_link *l) { - return l->state == WORKING_UNKNOWN; + return l->state == TIPC_LINK_PROBING; } -static int link_reset_unknown(struct tipc_link *l) +static int link_resetting(struct tipc_link *l) { - return l->state == RESET_UNKNOWN; + return l->state == TIPC_LINK_RESETTING; } -static int link_reset_reset(struct tipc_link *l) +static int link_establishing(struct tipc_link *l) { - return l->state == RESET_RESET; + return l->state == TIPC_LINK_ESTABLISHING; } static void link_handle_out_of_seq_msg(struct tipc_link *link, @@ -140,6 +140,8 @@ static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb); static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb); static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb); static void link_set_timer(struct tipc_link *link, unsigned long time); +static void link_activate(struct tipc_link *link); + /* * Simple link routines */ @@ -179,7 +181,7 @@ int tipc_link_is_up(struct tipc_link *l_ptr) { if (!l_ptr) return 0; - return link_working_working(l_ptr) || link_working_unknown(l_ptr); + return link_working(l_ptr) || link_probing(l_ptr); } int tipc_link_is_active(struct tipc_link *l) @@ -234,8 +236,11 @@ static void link_timeout(unsigned long data) } /* do all other link processing performed on a periodic basis */ - if (l_ptr->silent_intv_cnt || tipc_bclink_acks_missing(l_ptr->owner)) + if (l_ptr->silent_intv_cnt) link_state_event(l_ptr, SILENCE_EVT); + else if (link_working(l_ptr) && tipc_bclink_acks_missing(l_ptr->owner)) + tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0); + l_ptr->silent_intv_cnt++; if (skb_queue_len(&l_ptr->backlogq)) tipc_link_push_packets(l_ptr); @@ -304,7 +309,7 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr, l_ptr->peer_session = WILDCARD_SESSION; l_ptr->bearer_id = b_ptr->identity; link_set_supervision_props(l_ptr, b_ptr->tolerance); - l_ptr->state = RESET_UNKNOWN; + l_ptr->state = TIPC_LINK_RESETTING; l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg; msg = l_ptr->pmsg; @@ -366,6 +371,134 @@ void tipc_link_delete_list(struct net *net, unsigned int bearer_id) rcu_read_unlock(); } +/** + * 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 mtyp = 0, 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) + } actions = 0; + + if (l->exec_mode == TIPC_LINK_BLOCKED) + return rc; + + switch (l->state) { + case TIPC_LINK_WORKING: + switch (evt) { + case TRAFFIC_EVT: + case ACTIVATE_EVT: + break; + case SILENCE_EVT: + l->state = TIPC_LINK_PROBING; + actions |= SND_PROBE; + break; + case PEER_RESET_EVT: + actions |= LINK_RESET | SND_ACTIVATE; + break; + default: + pr_debug("%s%u WORKING\n", link_unk_evt, evt); + } + break; + case TIPC_LINK_PROBING: + switch (evt) { + case TRAFFIC_EVT: + case ACTIVATE_EVT: + l->state = TIPC_LINK_WORKING; + 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; + break; + default: + pr_err("%s%u PROBING\n", link_unk_evt, evt); + } + break; + case TIPC_LINK_RESETTING: + switch (evt) { + case TRAFFIC_EVT: + break; + case ACTIVATE_EVT: + pl = node_active_link(l->owner, 0); + if (pl && link_probing(pl)) + break; + actions |= LINK_ACTIVATE; + if (l->owner->working_links == 1) + tipc_link_sync_xmit(l); + break; + case PEER_RESET_EVT: + l->state = TIPC_LINK_ESTABLISHING; + actions |= SND_ACTIVATE; + break; + case SILENCE_EVT: + actions |= SND_RESET; + break; + default: + pr_err("%s%u in RESETTING\n", link_unk_evt, evt); + } + break; + case TIPC_LINK_ESTABLISHING: + switch (evt) { + case TRAFFIC_EVT: + case ACTIVATE_EVT: + pl = node_active_link(l->owner, 0); + if (pl && link_probing(pl)) + break; + actions |= LINK_ACTIVATE; + if (l->owner->working_links == 1) + tipc_link_sync_xmit(l); + break; + case PEER_RESET_EVT: + break; + case SILENCE_EVT: + actions |= SND_ACTIVATE; + break; + default: + pr_err("%s%u ESTABLISHING\n", link_unk_evt, evt); + } + break; + default: + pr_err("Unknown link state %u/%u\n", l->state, evt); + } + + /* 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) { + l->exec_mode = TIPC_LINK_OPEN; + rc |= TIPC_LINK_UP_EVT; + } + if (actions & (SND_STATE | SND_PROBE)) + mtyp = STATE_MSG; + if (actions & SND_RESET) + mtyp = RESET_MSG; + if (actions & SND_ACTIVATE) + mtyp = ACTIVATE_MSG; + if (actions & (SND_PROBE | SND_STATE | SND_RESET | SND_ACTIVATE)) + tipc_link_build_proto_msg(l, mtyp, actions & SND_PROBE, + 0, 0, 0, xmitq); + return rc; +} + /** * link_schedule_user - schedule a message sender for wakeup after congestion * @link: congested link @@ -474,9 +607,10 @@ void tipc_link_reset(struct tipc_link *l_ptr) /* Prepare for renewed mtu size negotiation */ l_ptr->mtu = l_ptr->advertised_mtu; - l_ptr->state = RESET_UNKNOWN; + l_ptr->state = TIPC_LINK_RESETTING; - if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET)) + if ((prev_state == TIPC_LINK_RESETTING) || + (prev_state == TIPC_LINK_ESTABLISHING)) return; tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id); @@ -515,6 +649,8 @@ static void link_activate(struct tipc_link *link) link->rcv_nxt = 1; link->stats.recv_info = 1; link->silent_intv_cnt = 0; + link->state = TIPC_LINK_WORKING; + link->exec_mode = TIPC_LINK_OPEN; tipc_node_link_up(node, link->bearer_id); tipc_bearer_add_dest(node->net, link->bearer_id, link->addr); } @@ -524,132 +660,29 @@ static void link_activate(struct tipc_link *link) * @l_ptr: pointer to link * @event: state machine event to process */ -static void link_state_event(struct tipc_link *l_ptr, unsigned int event) +static void link_state_event(struct tipc_link *l, unsigned int evt) { - struct tipc_link *other; + int rc; + struct sk_buff_head xmitq; + struct sk_buff *skb; - if (l_ptr->exec_mode == TIPC_LINK_BLOCKED) + if (l->exec_mode == TIPC_LINK_BLOCKED) return; - switch (l_ptr->state) { - case WORKING_WORKING: - switch (event) { - case TRAFFIC_EVT: - case ACTIVATE_MSG: - l_ptr->silent_intv_cnt = 0; - break; - case SILENCE_EVT: - if (!l_ptr->silent_intv_cnt) { - if (tipc_bclink_acks_missing(l_ptr->owner)) - tipc_link_proto_xmit(l_ptr, STATE_MSG, - 0, 0, 0, 0); - break; - } - l_ptr->state = WORKING_UNKNOWN; - tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0); - break; - case RESET_MSG: - pr_debug("%s<%s>, requested by peer\n", - link_rst_msg, l_ptr->name); - tipc_link_reset(l_ptr); - l_ptr->state = RESET_RESET; - tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, - 0, 0, 0, 0); - break; - default: - pr_debug("%s%u in WW state\n", link_unk_evt, event); - } - break; - case WORKING_UNKNOWN: - switch (event) { - case TRAFFIC_EVT: - case ACTIVATE_MSG: - l_ptr->state = WORKING_WORKING; - l_ptr->silent_intv_cnt = 0; - break; - case RESET_MSG: - pr_debug("%s<%s>, requested by peer while probing\n", - link_rst_msg, l_ptr->name); - tipc_link_reset(l_ptr); - l_ptr->state = RESET_RESET; - tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, - 0, 0, 0, 0); - break; - case SILENCE_EVT: - if (!l_ptr->silent_intv_cnt) { - l_ptr->state = WORKING_WORKING; - if (tipc_bclink_acks_missing(l_ptr->owner)) - tipc_link_proto_xmit(l_ptr, STATE_MSG, - 0, 0, 0, 0); - } else if (l_ptr->silent_intv_cnt < - l_ptr->abort_limit) { - tipc_link_proto_xmit(l_ptr, STATE_MSG, - 1, 0, 0, 0); - } else { /* Link has failed */ - pr_debug("%s<%s>, peer not responding\n", - link_rst_msg, l_ptr->name); - tipc_link_reset(l_ptr); - l_ptr->state = RESET_UNKNOWN; - tipc_link_proto_xmit(l_ptr, RESET_MSG, - 0, 0, 0, 0); - } - break; - default: - pr_err("%s%u in WU state\n", link_unk_evt, event); - } - break; - case RESET_UNKNOWN: - switch (event) { - case TRAFFIC_EVT: - break; - case ACTIVATE_MSG: - other = node_active_link(l_ptr->owner, 0); - if (other && link_working_unknown(other)) - break; - l_ptr->state = WORKING_WORKING; - link_activate(l_ptr); - tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0); - if (l_ptr->owner->working_links == 1) - tipc_link_sync_xmit(l_ptr); - break; - case RESET_MSG: - l_ptr->state = RESET_RESET; - tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, - 1, 0, 0, 0); - break; - case SILENCE_EVT: - tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0); - break; - default: - pr_err("%s%u in RU state\n", link_unk_evt, event); - } - break; - case RESET_RESET: - switch (event) { - case TRAFFIC_EVT: - case ACTIVATE_MSG: - other = node_active_link(l_ptr->owner, 0); - if (other && link_working_unknown(other)) - break; - l_ptr->state = WORKING_WORKING; - link_activate(l_ptr); - tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0); - if (l_ptr->owner->working_links == 1) - tipc_link_sync_xmit(l_ptr); - break; - case RESET_MSG: - break; - case SILENCE_EVT: - tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, - 0, 0, 0, 0); - break; - default: - pr_err("%s%u in RR state\n", link_unk_evt, event); - } - break; - default: - pr_err("Unknown link state %u/%u\n", l_ptr->state, event); - } + __skb_queue_head_init(&xmitq); + + rc = tipc_link_fsm_evt(l, evt, &xmitq); + + if (rc & TIPC_LINK_UP_EVT) + link_activate(l); + + if (rc & TIPC_LINK_DOWN_EVT) + tipc_link_reset(l); + + skb = __skb_dequeue(&xmitq); + if (!skb) + return; + tipc_bearer_send(l->owner->net, l->bearer_id, skb, &l->media_addr); } /** @@ -1102,7 +1135,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) link_prepare_wakeup(l_ptr); /* Process the incoming packet */ - if (unlikely(!link_working_working(l_ptr))) { + if (unlikely(!link_working(l_ptr))) { if (msg_user(msg) == LINK_PROTOCOL) { tipc_link_proto_rcv(l_ptr, skb); link_retrieve_defq(l_ptr, &head); @@ -1113,7 +1146,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) /* Traffic message. Conditionally activate link */ link_state_event(l_ptr, TRAFFIC_EVT); - if (link_working_working(l_ptr)) { + if (link_working(l_ptr)) { /* Re-insert buffer in front of queue */ __skb_queue_head(&head, skb); skb = NULL; @@ -1122,7 +1155,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) goto unlock; } - /* Link is now in state WORKING_WORKING */ + /* Link is now in state TIPC_LINK_WORKING */ if (unlikely(seq_no != l_ptr->rcv_nxt)) { link_handle_out_of_seq_msg(l_ptr, skb); link_retrieve_defq(l_ptr, &head); @@ -1365,16 +1398,15 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, switch (msg_type(msg)) { case RESET_MSG: - if (!link_working_unknown(l_ptr) && + if (!link_probing(l_ptr) && (l_ptr->peer_session != WILDCARD_SESSION)) { if (less_eq(msg_session(msg), l_ptr->peer_session)) break; /* duplicate or old reset: ignore */ } - if (!msg_redundant_link(msg) && (link_working_working(l_ptr) || - link_working_unknown(l_ptr))) { - /* - * peer has lost contact -- don't allow peer's links + if (!msg_redundant_link(msg) && (link_working(l_ptr) || + link_probing(l_ptr))) { + /* peer has lost contact -- don't allow peer's links * to reactivate before we recognize loss & clean up */ l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN; @@ -1432,7 +1464,7 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, link_state_event(l_ptr, TRAFFIC_EVT); l_ptr->stats.recv_states++; - if (link_reset_unknown(l_ptr)) + if (link_resetting(l_ptr)) break; if (less_eq(l_ptr->rcv_nxt, msg_next_sent(msg))) @@ -1822,14 +1854,14 @@ static void link_print(struct tipc_link *l_ptr, const char *str) pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name); rcu_read_unlock(); - if (link_working_unknown(l_ptr)) - pr_cont(":WU\n"); - else if (link_reset_reset(l_ptr)) - pr_cont(":RR\n"); - else if (link_reset_unknown(l_ptr)) - pr_cont(":RU\n"); - else if (link_working_working(l_ptr)) - pr_cont(":WW\n"); + if (link_probing(l_ptr)) + pr_cont(":P\n"); + else if (link_establishing(l_ptr)) + pr_cont(":E\n"); + else if (link_resetting(l_ptr)) + pr_cont(":R\n"); + else if (link_working(l_ptr)) + pr_cont(":W\n"); else pr_cont("\n"); } diff --git a/net/tipc/link.h b/net/tipc/link.h index 0509c6de03cd..ef68424f492d 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -58,6 +58,13 @@ enum { TIPC_LINK_TUNNEL }; +/* Events occurring at packet reception or at timeout + */ +enum { + TIPC_LINK_UP_EVT = 1, + TIPC_LINK_DOWN_EVT = (1 << 1) +}; + /* Starting value for maximum packet size negotiation on unicast links * (unless bearer MTU is less) */