/* * net/tipc/bcast.c: TIPC broadcast code * * Copyright (c) 2004-2006, Ericsson AB * Copyright (c) 2004, Intel Corporation. * Copyright (c) 2005, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "core.h" #include "msg.h" #include "dbg.h" #include "link.h" #include "net.h" #include "node.h" #include "port.h" #include "addr.h" #include "node_subscr.h" #include "name_distr.h" #include "bearer.h" #include "name_table.h" #include "bcast.h" #define MAX_PKT_DEFAULT_MCAST 1500 /* bcast link max packet size (fixed) */ #define BCLINK_WIN_DEFAULT 20 /* bcast link window size (default) */ #define BCLINK_LOG_BUF_SIZE 0 /* * Loss rate for incoming broadcast frames; used to test retransmission code. * Set to N to cause every N'th frame to be discarded; 0 => don't discard any. */ #define TIPC_BCAST_LOSS_RATE 0 /** * struct bcbearer_pair - a pair of bearers used by broadcast link * @primary: pointer to primary bearer * @secondary: pointer to secondary bearer * * Bearers must have same priority and same set of reachable destinations * to be paired. */ struct bcbearer_pair { struct bearer *primary; struct bearer *secondary; }; /** * struct bcbearer - bearer used by broadcast link * @bearer: (non-standard) broadcast bearer structure * @media: (non-standard) broadcast media structure * @bpairs: array of bearer pairs * @bpairs_temp: temporary array of bearer pairs used by tipc_bcbearer_sort() * @remains: temporary node map used by tipc_bcbearer_send() * @remains_new: temporary node map used tipc_bcbearer_send() * * Note: The fields labelled "temporary" are incorporated into the bearer * to avoid consuming potentially limited stack space through the use of * large local variables within multicast routines. Concurrent access is * prevented through use of the spinlock "bc_lock". */ struct bcbearer { struct bearer bearer; struct media media; struct bcbearer_pair bpairs[MAX_BEARERS]; struct bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1]; struct node_map remains; struct node_map remains_new; }; /** * struct bclink - link used for broadcast messages * @link: (non-standard) broadcast link structure * @node: (non-standard) node structure representing b'cast link's peer node * * Handles sequence numbering, fragmentation, bundling, etc. */ struct bclink { struct link link; struct node node; }; static struct bcbearer *bcbearer = NULL; static struct bclink *bclink = NULL; static struct link *bcl = NULL; static DEFINE_SPINLOCK(bc_lock); char tipc_bclink_name[] = "multicast-link"; static u32 buf_seqno(struct sk_buff *buf) { return msg_seqno(buf_msg(buf)); } static u32 bcbuf_acks(struct sk_buff *buf) { return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle; } static void bcbuf_set_acks(struct sk_buff *buf, u32 acks) { TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks; } static void bcbuf_decr_acks(struct sk_buff *buf) { bcbuf_set_acks(buf, bcbuf_acks(buf) - 1); } /** * bclink_set_gap - set gap according to contents of current deferred pkt queue * * Called with 'node' locked, bc_lock unlocked */ static void bclink_set_gap(struct node *n_ptr) { struct sk_buff *buf = n_ptr->bclink.deferred_head; n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = mod(n_ptr->bclink.last_in); if (unlikely(buf != NULL)) n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1); } /** * bclink_ack_allowed - test if ACK or NACK message can be sent at this moment * * This mechanism endeavours to prevent all nodes in network from trying * to ACK or NACK at the same time. * * Note: TIPC uses a different trigger to distribute ACKs than it does to * distribute NACKs, but tries to use the same spacing (divide by 16). */ static int bclink_ack_allowed(u32 n) { return((n % TIPC_MIN_LINK_WIN) == tipc_own_tag); } /** * bclink_retransmit_pkt - retransmit broadcast packets * @after: sequence number of last packet to *not* retransmit * @to: sequence number of last packet to retransmit * * Called with bc_lock locked */ static void bclink_retransmit_pkt(u32 after, u32 to) { struct sk_buff *buf; buf = bcl->first_out; while (buf && less_eq(buf_seqno(buf), after)) { buf = buf->next; } tipc_link_retransmit(bcl, buf, mod(to - after)); } /** * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets * @n_ptr: node that sent acknowledgement info * @acked: broadcast sequence # that has been acknowledged * * Node is locked, bc_lock unlocked. */ void tipc_bclink_acknowledge(struct node *n_ptr, u32 acked) { struct sk_buff *crs; struct sk_buff *next; unsigned int released = 0; if (less_eq(acked, n_ptr->bclink.acked)) return; spin_lock_bh(&bc_lock); /* Skip over packets that node has previously acknowledged */ crs = bcl->first_out; while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked)) { crs = crs->next; } /* Update packets that node is now acknowledging */ while (crs && less_eq(buf_seqno(crs), acked)) { next = crs->next; bcbuf_decr_acks(crs); if (bcbuf_acks(crs) == 0) { bcl->first_out = next; bcl->out_queue_size--; buf_discard(crs); released = 1; } crs = next; } n_ptr->bclink.acked = acked; /* Try resolving broadcast link congestion, if necessary */ if (unlikely(bcl->next_out)) tipc_link_push_queue(bcl); if (unlikely(released && !list_empty(&bcl->waiting_ports))) tipc_link_wakeup_ports(bcl, 0); spin_unlock_bh(&bc_lock); } /** * bclink_send_ack - unicast an ACK msg * * tipc_net_lock and node lock set */ static void bclink_send_ack(struct node *n_ptr) { struct link *l_ptr = n_ptr->active_links[n_ptr->addr & 1]; if (l_ptr != NULL) tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); } /** * bclink_send_nack- broadcast a NACK msg * * tipc_net_lock and node lock set */ static void bclink_send_nack(struct node *n_ptr) { struct sk_buff *buf; struct tipc_msg *msg; if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to)) return; buf = buf_acquire(INT_H_SIZE); if (buf) { msg = buf_msg(buf); msg_init(msg, BCAST_PROTOCOL, STATE_MSG, TIPC_OK, INT_H_SIZE, n_ptr->addr); msg_set_mc_netid(msg, tipc_net_id); msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in)); msg_set_bcgap_after(msg, n_ptr->bclink.gap_after); msg_set_bcgap_to(msg, n_ptr->bclink.gap_to); msg_set_bcast_tag(msg, tipc_own_tag); if (tipc_bearer_send(&bcbearer->bearer, buf, NULL)) { bcl->stats.sent_nacks++; buf_discard(buf); } else { tipc_bearer_schedule(bcl->b_ptr, bcl); bcl->proto_msg_queue = buf; bcl->stats.bearer_congs++; } /* * Ensure we doesn't send another NACK msg to the node * until 16 more deferred messages arrive from it * (i.e. helps prevent all nodes from NACK'ing at same time) */ n_ptr->bclink.nack_sync = tipc_own_tag; } } /** * tipc_bclink_check_gap - send a NACK if a sequence gap exists * * tipc_net_lock and node lock set */ void tipc_bclink_check_gap(struct node *n_ptr, u32 last_sent) { if (!n_ptr->bclink.supported || less_eq(last_sent, mod(n_ptr->bclink.last_in))) return; bclink_set_gap(n_ptr); if (n_ptr->bclink.gap_after == n_ptr->bclink.gap_to) n_ptr->bclink.gap_to = last_sent; bclink_send_nack(n_ptr); } /** * tipc_bclink_peek_nack - process a NACK msg meant for another node * * Only tipc_net_lock set. */ static void tipc_bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to) { struct node *n_ptr = tipc_node_find(dest); u32 my_after, my_to; if (unlikely(!n_ptr || !tipc_node_is_up(n_ptr))) return; tipc_node_lock(n_ptr); /* * Modify gap to suppress unnecessary NACKs from this node */ my_after = n_ptr->bclink.gap_after; my_to = n_ptr->bclink.gap_to; if (less_eq(gap_after, my_after)) { if (less(my_after, gap_to) && less(gap_to, my_to)) n_ptr->bclink.gap_after = gap_to; else if (less_eq(my_to, gap_to)) n_ptr->bclink.gap_to = n_ptr->bclink.gap_after; } else if (less_eq(gap_after, my_to)) { if (less_eq(my_to, gap_to)) n_ptr->bclink.gap_to = gap_after; } else { /* * Expand gap if missing bufs not in deferred queue: */ struct sk_buff *buf = n_ptr->bclink.deferred_head; u32 prev = n_ptr->bclink.gap_to; for (; buf; buf = buf->next) { u32 seqno = buf_seqno(buf); if (mod(seqno - prev) != 1) { buf = NULL; break; } if (seqno == gap_after) break; prev = seqno; } if (buf == NULL) n_ptr->bclink.gap_to = gap_after; } /* * Some nodes may send a complementary NACK now: */ if (bclink_ack_allowed(sender_tag + 1)) { if (n_ptr->bclink.gap_to != n_ptr->bclink.gap_after) { bclink_send_nack(n_ptr); bclink_set_gap(n_ptr); } } tipc_node_unlock(n_ptr); } /** * tipc_bclink_send_msg - broadcast a packet to all nodes in cluster */ int tipc_bclink_send_msg(struct sk_buff *buf) { int res; spin_lock_bh(&bc_lock); res = tipc_link_send_buf(bcl, buf); if (unlikely(res == -ELINKCONG)) buf_discard(buf); else bcl->stats.sent_info++; if (bcl->out_queue_size > bcl->stats.max_queue_sz) bcl->stats.max_queue_sz = bcl->out_queue_size; bcl->stats.queue_sz_counts++; bcl->stats.accu_queue_sz += bcl->out_queue_size; spin_unlock_bh(&bc_lock); return res; } /** * tipc_bclink_recv_pkt - receive a broadcast packet, and deliver upwards * * tipc_net_lock is read_locked, no other locks set */ void tipc_bclink_recv_pkt(struct sk_buff *buf) { #if (TIPC_BCAST_LOSS_RATE) static int rx_count = 0; #endif struct tipc_msg *msg = buf_msg(buf); struct node* node = tipc_node_find(msg_prevnode(msg)); u32 next_in; u32 seqno; struct sk_buff *deferred; msg_dbg(msg, "<BC<<<"); if (unlikely(!node || !tipc_node_is_up(node) || !node->bclink.supported || (msg_mc_netid(msg) != tipc_net_id))) { buf_discard(buf); return; } if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) { msg_dbg(msg, "<BCNACK<<<"); if (msg_destnode(msg) == tipc_own_addr) { tipc_node_lock(node); tipc_bclink_acknowledge(node, msg_bcast_ack(msg)); tipc_node_unlock(node); spin_lock_bh(&bc_lock); bcl->stats.recv_nacks++; bcl->owner->next = node; /* remember requestor */ bclink_retransmit_pkt(msg_bcgap_after(msg), msg_bcgap_to(msg)); bcl->owner->next = NULL; spin_unlock_bh(&bc_lock); } else { tipc_bclink_peek_nack(msg_destnode(msg), msg_bcast_tag(msg), msg_bcgap_after(msg), msg_bcgap_to(msg)); } buf_discard(buf); return; } #if (TIPC_BCAST_LOSS_RATE) if (++rx_count == TIPC_BCAST_LOSS_RATE) { rx_count = 0; buf_discard(buf); return; } #endif tipc_node_lock(node); receive: deferred = node->bclink.deferred_head; next_in = mod(node->bclink.last_in + 1); seqno = msg_seqno(msg); if (likely(seqno == next_in)) { bcl->stats.recv_info++; node->bclink.last_in++; bclink_set_gap(node); if (unlikely(bclink_ack_allowed(seqno))) { bclink_send_ack(node); bcl->stats.sent_acks++; } if (likely(msg_isdata(msg))) { tipc_node_unlock(node); tipc_port_recv_mcast(buf, NULL); } else if (msg_user(msg) == MSG_BUNDLER) { bcl->stats.recv_bundles++; bcl->stats.recv_bundled += msg_msgcnt(msg); tipc_node_unlock(node); tipc_link_recv_bundle(buf); } else if (msg_user(msg) == MSG_FRAGMENTER) { bcl->stats.recv_fragments++; if (tipc_link_recv_fragment(&node->bclink.defragm, &buf, &msg)) bcl->stats.recv_fragmented++; tipc_node_unlock(node); tipc_net_route_msg(buf); } else { tipc_node_unlock(node); tipc_net_route_msg(buf); } if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) { tipc_node_lock(node); buf = deferred; msg = buf_msg(buf); node->bclink.deferred_head = deferred->next; goto receive; } return; } else if (less(next_in, seqno)) { u32 gap_after = node->bclink.gap_after; u32 gap_to = node->bclink.gap_to; if (tipc_link_defer_pkt(&node->bclink.deferred_head, &node->bclink.deferred_tail, buf)) { node->bclink.nack_sync++; bcl->stats.deferred_recv++; if (seqno == mod(gap_after + 1)) node->bclink.gap_after = seqno; else if (less(gap_after, seqno) && less(seqno, gap_to)) node->bclink.gap_to = seqno; } if (bclink_ack_allowed(node->bclink.nack_sync)) { if (gap_to != gap_after) bclink_send_nack(node); bclink_set_gap(node); } } else { bcl->stats.duplicates++; buf_discard(buf); } tipc_node_unlock(node); } u32 tipc_bclink_get_last_sent(void) { u32 last_sent = mod(bcl->next_out_no - 1); if (bcl->next_out) last_sent = mod(buf_seqno(bcl->next_out) - 1); return last_sent; } u32 tipc_bclink_acks_missing(struct node *n_ptr) { return (n_ptr->bclink.supported && (tipc_bclink_get_last_sent() != n_ptr->bclink.acked)); } /** * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer * * Send through as many bearers as necessary to reach all nodes * that support TIPC multicasting. * * Returns 0 if packet sent successfully, non-zero if not */ static int tipc_bcbearer_send(struct sk_buff *buf, struct tipc_bearer *unused1, struct tipc_media_addr *unused2) { static int send_count = 0; int bp_index; int swap_time; /* Prepare buffer for broadcasting (if first time trying to send it) */ if (likely(!msg_non_seq(buf_msg(buf)))) { struct tipc_msg *msg; assert(tipc_cltr_bcast_nodes.count != 0); bcbuf_set_acks(buf, tipc_cltr_bcast_nodes.count); msg = buf_msg(buf); msg_set_non_seq(msg); msg_set_mc_netid(msg, tipc_net_id); } /* Determine if bearer pairs should be swapped following this attempt */ if ((swap_time = (++send_count >= 10))) send_count = 0; /* Send buffer over bearers until all targets reached */ bcbearer->remains = tipc_cltr_bcast_nodes; for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) { struct bearer *p = bcbearer->bpairs[bp_index].primary; struct bearer *s = bcbearer->bpairs[bp_index].secondary; if (!p) break; /* no more bearers to try */ tipc_nmap_diff(&bcbearer->remains, &p->nodes, &bcbearer->remains_new); if (bcbearer->remains_new.count == bcbearer->remains.count) continue; /* bearer pair doesn't add anything */ if (!p->publ.blocked && !p->media->send_msg(buf, &p->publ, &p->media->bcast_addr)) { if (swap_time && s && !s->publ.blocked) goto swap; else goto update; } if (!s || s->publ.blocked || s->media->send_msg(buf, &s->publ, &s->media->bcast_addr)) continue; /* unable to send using bearer pair */ swap: bcbearer->bpairs[bp_index].primary = s; bcbearer->bpairs[bp_index].secondary = p; update: if (bcbearer->remains_new.count == 0) return TIPC_OK; bcbearer->remains = bcbearer->remains_new; } /* Unable to reach all targets */ bcbearer->bearer.publ.blocked = 1; bcl->stats.bearer_congs++; return ~TIPC_OK; } /** * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer */ void tipc_bcbearer_sort(void) { struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp; struct bcbearer_pair *bp_curr; int b_index; int pri; spin_lock_bh(&bc_lock); /* Group bearers by priority (can assume max of two per priority) */ memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp)); for (b_index = 0; b_index < MAX_BEARERS; b_index++) { struct bearer *b = &tipc_bearers[b_index]; if (!b->active || !b->nodes.count) continue; if (!bp_temp[b->priority].primary) bp_temp[b->priority].primary = b; else bp_temp[b->priority].secondary = b; } /* Create array of bearer pairs for broadcasting */ bp_curr = bcbearer->bpairs; memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs)); for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) { if (!bp_temp[pri].primary) continue; bp_curr->primary = bp_temp[pri].primary; if (bp_temp[pri].secondary) { if (tipc_nmap_equal(&bp_temp[pri].primary->nodes, &bp_temp[pri].secondary->nodes)) { bp_curr->secondary = bp_temp[pri].secondary; } else { bp_curr++; bp_curr->primary = bp_temp[pri].secondary; } } bp_curr++; } spin_unlock_bh(&bc_lock); } /** * tipc_bcbearer_push - resolve bearer congestion * * Forces bclink to push out any unsent packets, until all packets are gone * or congestion reoccurs. * No locks set when function called */ void tipc_bcbearer_push(void) { struct bearer *b_ptr; spin_lock_bh(&bc_lock); b_ptr = &bcbearer->bearer; if (b_ptr->publ.blocked) { b_ptr->publ.blocked = 0; tipc_bearer_lock_push(b_ptr); } spin_unlock_bh(&bc_lock); } int tipc_bclink_stats(char *buf, const u32 buf_size) { struct print_buf pb; if (!bcl) return 0; tipc_printbuf_init(&pb, buf, buf_size); spin_lock_bh(&bc_lock); tipc_printf(&pb, "Link <%s>\n" " Window:%u packets\n", bcl->name, bcl->queue_limit[0]); tipc_printf(&pb, " RX packets:%u fragments:%u/%u bundles:%u/%u\n", bcl->stats.recv_info, bcl->stats.recv_fragments, bcl->stats.recv_fragmented, bcl->stats.recv_bundles, bcl->stats.recv_bundled); tipc_printf(&pb, " TX packets:%u fragments:%u/%u bundles:%u/%u\n", bcl->stats.sent_info, bcl->stats.sent_fragments, bcl->stats.sent_fragmented, bcl->stats.sent_bundles, bcl->stats.sent_bundled); tipc_printf(&pb, " RX naks:%u defs:%u dups:%u\n", bcl->stats.recv_nacks, bcl->stats.deferred_recv, bcl->stats.duplicates); tipc_printf(&pb, " TX naks:%u acks:%u dups:%u\n", bcl->stats.sent_nacks, bcl->stats.sent_acks, bcl->stats.retransmitted); tipc_printf(&pb, " Congestion bearer:%u link:%u Send queue max:%u avg:%u\n", bcl->stats.bearer_congs, bcl->stats.link_congs, bcl->stats.max_queue_sz, bcl->stats.queue_sz_counts ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts) : 0); spin_unlock_bh(&bc_lock); return tipc_printbuf_validate(&pb); } int tipc_bclink_reset_stats(void) { if (!bcl) return -ENOPROTOOPT; spin_lock_bh(&bc_lock); memset(&bcl->stats, 0, sizeof(bcl->stats)); spin_unlock_bh(&bc_lock); return TIPC_OK; } int tipc_bclink_set_queue_limits(u32 limit) { if (!bcl) return -ENOPROTOOPT; if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN)) return -EINVAL; spin_lock_bh(&bc_lock); tipc_link_set_queue_limits(bcl, limit); spin_unlock_bh(&bc_lock); return TIPC_OK; } int tipc_bclink_init(void) { bcbearer = kzalloc(sizeof(*bcbearer), GFP_ATOMIC); bclink = kzalloc(sizeof(*bclink), GFP_ATOMIC); if (!bcbearer || !bclink) { nomem: warn("Multicast link creation failed, no memory\n"); kfree(bcbearer); bcbearer = NULL; kfree(bclink); bclink = NULL; return -ENOMEM; } INIT_LIST_HEAD(&bcbearer->bearer.cong_links); bcbearer->bearer.media = &bcbearer->media; bcbearer->media.send_msg = tipc_bcbearer_send; sprintf(bcbearer->media.name, "tipc-multicast"); bcl = &bclink->link; INIT_LIST_HEAD(&bcl->waiting_ports); bcl->next_out_no = 1; spin_lock_init(&bclink->node.lock); bcl->owner = &bclink->node; bcl->max_pkt = MAX_PKT_DEFAULT_MCAST; tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT); bcl->b_ptr = &bcbearer->bearer; bcl->state = WORKING_WORKING; sprintf(bcl->name, tipc_bclink_name); if (BCLINK_LOG_BUF_SIZE) { char *pb = kmalloc(BCLINK_LOG_BUF_SIZE, GFP_ATOMIC); if (!pb) goto nomem; tipc_printbuf_init(&bcl->print_buf, pb, BCLINK_LOG_BUF_SIZE); } return TIPC_OK; } void tipc_bclink_stop(void) { spin_lock_bh(&bc_lock); if (bcbearer) { tipc_link_stop(bcl); if (BCLINK_LOG_BUF_SIZE) kfree(bcl->print_buf.buf); bcl = NULL; kfree(bclink); bclink = NULL; kfree(bcbearer); bcbearer = NULL; } spin_unlock_bh(&bc_lock); }