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-rw-r--r--net/tipc/bcast.c83
1 files changed, 48 insertions, 35 deletions
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 2c4ecbe..1bb7570 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;
};
/**
@@ -102,7 +117,7 @@ struct bclink {
static struct bcbearer *bcbearer = NULL;
static struct bclink *bclink = NULL;
static struct link *bcl = NULL;
-static spinlock_t bc_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(bc_lock);
char tipc_bclink_name[] = "multicast-link";
@@ -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);
@@ -783,7 +796,7 @@ int tipc_bclink_init(void)
memset(bclink, 0, sizeof(struct bclink));
INIT_LIST_HEAD(&bcl->waiting_ports);
bcl->next_out_no = 1;
- bclink->node.lock = SPIN_LOCK_UNLOCKED;
+ 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);
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