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-rw-r--r--net/tipc/socket.c247
1 files changed, 244 insertions, 3 deletions
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 70eacea..6a69967 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -35,7 +35,6 @@
*/
#include "core.h"
-#include "ref.h"
#include "name_table.h"
#include "node.h"
#include "link.h"
@@ -61,6 +60,11 @@ static int tipc_sk_publish(struct tipc_port *port, uint scope,
struct tipc_name_seq const *seq);
static int tipc_sk_withdraw(struct tipc_port *port, uint scope,
struct tipc_name_seq const *seq);
+static u32 tipc_sk_ref_acquire(struct tipc_sock *tsk);
+static void tipc_sk_ref_discard(u32 ref);
+static struct tipc_sock *tipc_sk_get(u32 ref);
+static struct tipc_sock *tipc_sk_get_next(u32 *ref);
+static void tipc_sk_put(struct tipc_sock *tsk);
static const struct proto_ops packet_ops;
static const struct proto_ops stream_ops;
@@ -271,7 +275,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
tsk = tipc_sk(sk);
port = &tsk->port;
- ref = tipc_ref_acquire(tsk);
+ ref = tipc_sk_ref_acquire(tsk);
if (!ref) {
pr_warn("Socket create failed; reference table exhausted\n");
return -ENOMEM;
@@ -434,7 +438,7 @@ static int tipc_release(struct socket *sock)
}
tipc_sk_withdraw(port, 0, NULL);
- tipc_ref_discard(port->ref);
+ tipc_sk_ref_discard(port->ref);
k_cancel_timer(&port->timer);
if (port->connected) {
buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
@@ -2254,6 +2258,243 @@ void tipc_sk_reinit(void)
}
/**
+ * struct reference - TIPC socket reference entry
+ * @tsk: pointer to socket associated with reference entry
+ * @ref: reference value for socket (combines instance & array index info)
+ */
+struct reference {
+ struct tipc_sock *tsk;
+ u32 ref;
+};
+
+/**
+ * struct tipc_ref_table - table of TIPC socket reference entries
+ * @entries: pointer to array of reference entries
+ * @capacity: array index of first unusable entry
+ * @init_point: array index of first uninitialized entry
+ * @first_free: array index of first unused socket reference entry
+ * @last_free: array index of last unused socket reference entry
+ * @index_mask: bitmask for array index portion of reference values
+ * @start_mask: initial value for instance value portion of reference values
+ */
+struct ref_table {
+ struct reference *entries;
+ u32 capacity;
+ u32 init_point;
+ u32 first_free;
+ u32 last_free;
+ u32 index_mask;
+ u32 start_mask;
+};
+
+/* Socket reference table consists of 2**N entries.
+ *
+ * State Socket ptr Reference
+ * ----- ---------- ---------
+ * In use non-NULL XXXX|own index
+ * (XXXX changes each time entry is acquired)
+ * Free NULL YYYY|next free index
+ * (YYYY is one more than last used XXXX)
+ * Uninitialized NULL 0
+ *
+ * Entry 0 is not used; this allows index 0 to denote the end of the free list.
+ *
+ * Note that a reference value of 0 does not necessarily indicate that an
+ * entry is uninitialized, since the last entry in the free list could also
+ * have a reference value of 0 (although this is unlikely).
+ */
+
+static struct ref_table tipc_ref_table;
+
+static DEFINE_RWLOCK(ref_table_lock);
+
+/**
+ * tipc_ref_table_init - create reference table for sockets
+ */
+int tipc_sk_ref_table_init(u32 req_sz, u32 start)
+{
+ struct reference *table;
+ u32 actual_sz;
+
+ /* account for unused entry, then round up size to a power of 2 */
+
+ req_sz++;
+ for (actual_sz = 16; actual_sz < req_sz; actual_sz <<= 1) {
+ /* do nothing */
+ };
+
+ /* allocate table & mark all entries as uninitialized */
+ table = vzalloc(actual_sz * sizeof(struct reference));
+ if (table == NULL)
+ return -ENOMEM;
+
+ tipc_ref_table.entries = table;
+ tipc_ref_table.capacity = req_sz;
+ tipc_ref_table.init_point = 1;
+ tipc_ref_table.first_free = 0;
+ tipc_ref_table.last_free = 0;
+ tipc_ref_table.index_mask = actual_sz - 1;
+ tipc_ref_table.start_mask = start & ~tipc_ref_table.index_mask;
+
+ return 0;
+}
+
+/**
+ * tipc_ref_table_stop - destroy reference table for sockets
+ */
+void tipc_sk_ref_table_stop(void)
+{
+ if (!tipc_ref_table.entries)
+ return;
+ vfree(tipc_ref_table.entries);
+ tipc_ref_table.entries = NULL;
+}
+
+/* tipc_ref_acquire - create reference to a socket
+ *
+ * Register an socket pointer in the reference table.
+ * Returns a unique reference value that is used from then on to retrieve the
+ * socket pointer, or to determine if the socket has been deregistered.
+ */
+u32 tipc_sk_ref_acquire(struct tipc_sock *tsk)
+{
+ u32 index;
+ u32 index_mask;
+ u32 next_plus_upper;
+ u32 ref = 0;
+ struct reference *entry;
+
+ if (unlikely(!tsk)) {
+ pr_err("Attempt to acquire ref. to non-existent obj\n");
+ return 0;
+ }
+ if (unlikely(!tipc_ref_table.entries)) {
+ pr_err("Ref. table not found in acquisition attempt\n");
+ return 0;
+ }
+
+ /* Take a free entry, if available; otherwise initialize a new one */
+ write_lock_bh(&ref_table_lock);
+ index = tipc_ref_table.first_free;
+ entry = &tipc_ref_table.entries[index];
+
+ if (likely(index)) {
+ index = tipc_ref_table.first_free;
+ entry = &tipc_ref_table.entries[index];
+ index_mask = tipc_ref_table.index_mask;
+ next_plus_upper = entry->ref;
+ tipc_ref_table.first_free = next_plus_upper & index_mask;
+ ref = (next_plus_upper & ~index_mask) + index;
+ entry->tsk = tsk;
+ } else if (tipc_ref_table.init_point < tipc_ref_table.capacity) {
+ index = tipc_ref_table.init_point++;
+ entry = &tipc_ref_table.entries[index];
+ ref = tipc_ref_table.start_mask + index;
+ }
+
+ if (ref) {
+ entry->ref = ref;
+ entry->tsk = tsk;
+ }
+ write_unlock_bh(&ref_table_lock);
+ return ref;
+}
+
+/* tipc_sk_ref_discard - invalidate reference to an socket
+ *
+ * Disallow future references to an socket and free up the entry for re-use.
+ */
+void tipc_sk_ref_discard(u32 ref)
+{
+ struct reference *entry;
+ u32 index;
+ u32 index_mask;
+
+ if (unlikely(!tipc_ref_table.entries)) {
+ pr_err("Ref. table not found during discard attempt\n");
+ return;
+ }
+
+ index_mask = tipc_ref_table.index_mask;
+ index = ref & index_mask;
+ entry = &tipc_ref_table.entries[index];
+
+ write_lock_bh(&ref_table_lock);
+
+ if (unlikely(!entry->tsk)) {
+ pr_err("Attempt to discard ref. to non-existent socket\n");
+ goto exit;
+ }
+ if (unlikely(entry->ref != ref)) {
+ pr_err("Attempt to discard non-existent reference\n");
+ goto exit;
+ }
+
+ /* Mark entry as unused; increment instance part of entry's
+ * reference to invalidate any subsequent references
+ */
+
+ entry->tsk = NULL;
+ entry->ref = (ref & ~index_mask) + (index_mask + 1);
+
+ /* Append entry to free entry list */
+ if (unlikely(tipc_ref_table.first_free == 0))
+ tipc_ref_table.first_free = index;
+ else
+ tipc_ref_table.entries[tipc_ref_table.last_free].ref |= index;
+ tipc_ref_table.last_free = index;
+exit:
+ write_unlock_bh(&ref_table_lock);
+}
+
+/* tipc_sk_get - find referenced socket and return pointer to it
+ */
+struct tipc_sock *tipc_sk_get(u32 ref)
+{
+ struct reference *entry;
+ struct tipc_sock *tsk;
+
+ if (unlikely(!tipc_ref_table.entries))
+ return NULL;
+ read_lock_bh(&ref_table_lock);
+ entry = &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
+ tsk = entry->tsk;
+ if (likely(tsk && (entry->ref == ref)))
+ sock_hold(&tsk->sk);
+ else
+ tsk = NULL;
+ read_unlock_bh(&ref_table_lock);
+ return tsk;
+}
+
+/* tipc_sk_get_next - lock & return next socket after referenced one
+*/
+struct tipc_sock *tipc_sk_get_next(u32 *ref)
+{
+ struct reference *entry;
+ struct tipc_sock *tsk = NULL;
+ uint index = *ref & tipc_ref_table.index_mask;
+
+ read_lock_bh(&ref_table_lock);
+ while (++index < tipc_ref_table.capacity) {
+ entry = &tipc_ref_table.entries[index];
+ if (!entry->tsk)
+ continue;
+ tsk = entry->tsk;
+ sock_hold(&tsk->sk);
+ *ref = entry->ref;
+ break;
+ }
+ read_unlock_bh(&ref_table_lock);
+ return tsk;
+}
+
+static void tipc_sk_put(struct tipc_sock *tsk)
+{
+ sock_put(&tsk->sk);
+}
+
+/**
* tipc_setsockopt - set socket option
* @sock: socket structure
* @lvl: option level
generated by cgit v0.10.2 at 2024-11-05 15:00:04 (GMT)