diff options
Diffstat (limited to 'net/tipc/bcast.c')
| -rw-r--r-- | net/tipc/bcast.c | 79 |
1 files changed, 46 insertions, 33 deletions
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c index 2c4ecbe..5412804 100644 --- a/net/tipc/bcast.c +++ b/net/tipc/bcast.c @@ -49,13 +49,19 @@ #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 @@ -75,7 +81,14 @@ struct bcbearer_pair { * @bearer: (non-standard) broadcast bearer structure * @media: (non-standard) broadcast media structure * @bpairs: array of bearer pairs - * @bpairs_temp: array of bearer pairs used during creation of "bpairs" + * @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 { @@ -83,6 +96,8 @@ struct bcbearer { 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; }; /** @@ -165,21 +180,18 @@ static int bclink_ack_allowed(u32 n) * @after: sequence number of last packet to *not* retransmit * @to: sequence number of last packet to retransmit * - * Called with 'node' locked, bc_lock unlocked + * Called with bc_lock locked */ static void bclink_retransmit_pkt(u32 after, u32 to) { struct sk_buff *buf; - spin_lock_bh(&bc_lock); buf = bcl->first_out; while (buf && less_eq(buf_seqno(buf), after)) { buf = buf->next; } - if (buf != NULL) - tipc_link_retransmit(bcl, buf, mod(to - after)); - spin_unlock_bh(&bc_lock); + tipc_link_retransmit(bcl, buf, mod(to - after)); } /** @@ -346,8 +358,10 @@ static void tipc_bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 g for (; buf; buf = buf->next) { u32 seqno = buf_seqno(buf); - if (mod(seqno - prev) != 1) + if (mod(seqno - prev) != 1) { buf = NULL; + break; + } if (seqno == gap_after) break; prev = seqno; @@ -399,7 +413,10 @@ int tipc_bclink_send_msg(struct sk_buff *buf) */ 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; @@ -420,9 +437,13 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf) 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), @@ -433,6 +454,14 @@ void tipc_bclink_recv_pkt(struct sk_buff *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; @@ -531,12 +560,8 @@ static int tipc_bcbearer_send(struct sk_buff *buf, { static int send_count = 0; - struct node_map *remains; - struct node_map *remains_new; - struct node_map *remains_tmp; int bp_index; int swap_time; - int err; /* Prepare buffer for broadcasting (if first time trying to send it) */ @@ -557,9 +582,7 @@ static int tipc_bcbearer_send(struct sk_buff *buf, /* Send buffer over bearers until all targets reached */ - remains = kmalloc(sizeof(struct node_map), GFP_ATOMIC); - remains_new = kmalloc(sizeof(struct node_map), GFP_ATOMIC); - *remains = tipc_cltr_bcast_nodes; + bcbearer->remains = tipc_cltr_bcast_nodes; for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) { struct bearer *p = bcbearer->bpairs[bp_index].primary; @@ -568,8 +591,8 @@ static int tipc_bcbearer_send(struct sk_buff *buf, if (!p) break; /* no more bearers to try */ - tipc_nmap_diff(remains, &p->nodes, remains_new); - if (remains_new->count == remains->count) + 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 && @@ -587,27 +610,17 @@ swap: bcbearer->bpairs[bp_index].primary = s; bcbearer->bpairs[bp_index].secondary = p; update: - if (remains_new->count == 0) { - err = TIPC_OK; - goto out; - } + if (bcbearer->remains_new.count == 0) + return TIPC_OK; - /* swap map */ - remains_tmp = remains; - remains = remains_new; - remains_new = remains_tmp; + bcbearer->remains = bcbearer->remains_new; } /* Unable to reach all targets */ bcbearer->bearer.publ.blocked = 1; bcl->stats.bearer_congs++; - err = ~TIPC_OK; - - out: - kfree(remains_new); - kfree(remains); - return err; + return ~TIPC_OK; } /** @@ -765,7 +778,7 @@ int tipc_bclink_init(void) bclink = kmalloc(sizeof(*bclink), GFP_ATOMIC); if (!bcbearer || !bclink) { nomem: - warn("Memory squeeze; Failed to create multicast link\n"); + warn("Multicast link creation failed, no memory\n"); kfree(bcbearer); bcbearer = NULL; kfree(bclink); |