[PATCH 5/6] VSOCK: utility functions.

[George Zhang <georgezhang@vmware.com>]

VSOCK utility functions for Linux VSocket module.

Signed-off-by: George Zhang <georgezhang@vmware.com>
Acked-by: Andy king <acking@vmware.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
---
 net/vmw_vsock/util.c |  345 ++++++++++++++++++++++++++++++++++++++++++++++++++
 net/vmw_vsock/util.h |  187 +++++++++++++++++++++++++++
 2 files changed, 532 insertions(+), 0 deletions(-)
 create mode 100644 net/vmw_vsock/util.c
 create mode 100644 net/vmw_vsock/util.h

diff --git a/net/vmw_vsock/util.c b/net/vmw_vsock/util.c
new file mode 100644
index 0000000..b77cafa
--- /dev/null
+++ b/net/vmw_vsock/util.c
@@ -0,0 +1,345 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2007-2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <net/sock.h>
+
+#include "af_vsock.h"
+#include "util.h"
+
+struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
+struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
+
+DEFINE_SPINLOCK(vsock_table_lock);
+
+void vsock_vmci_log_pkt(char const *function, u32 line,
+			struct vsock_packet *pkt)
+{
+	char buf[256];
+	char *cur = buf;
+	int left = sizeof(buf);
+	int written = 0;
+	char *type_strings[] = {
+		[VSOCK_PACKET_TYPE_INVALID] = "INVALID",
+		[VSOCK_PACKET_TYPE_REQUEST] = "REQUEST",
+		[VSOCK_PACKET_TYPE_NEGOTIATE] = "NEGOTIATE",
+		[VSOCK_PACKET_TYPE_OFFER] = "OFFER",
+		[VSOCK_PACKET_TYPE_ATTACH] = "ATTACH",
+		[VSOCK_PACKET_TYPE_WROTE] = "WROTE",
+		[VSOCK_PACKET_TYPE_READ] = "READ",
+		[VSOCK_PACKET_TYPE_RST] = "RST",
+		[VSOCK_PACKET_TYPE_SHUTDOWN] = "SHUTDOWN",
+		[VSOCK_PACKET_TYPE_WAITING_WRITE] = "WAITING_WRITE",
+		[VSOCK_PACKET_TYPE_WAITING_READ] = "WAITING_READ",
+		[VSOCK_PACKET_TYPE_REQUEST2] = "REQUEST2",
+		[VSOCK_PACKET_TYPE_NEGOTIATE2] = "NEGOTIATE2",
+	};
+
+	written = snprintf(cur, left, "PKT: %u:%u -> %u:%u",
+			   pkt->dg.src.context, pkt->src_port,
+			   pkt->dg.dst.context, pkt->dst_port);
+	if (written >= left)
+		goto error;
+
+	left -= written;
+	cur += written;
+
+	switch (pkt->type) {
+	case VSOCK_PACKET_TYPE_REQUEST:
+	case VSOCK_PACKET_TYPE_NEGOTIATE:
+		written = snprintf(cur, left, ", %s, size = %" FMT64 "u",
+				   type_strings[pkt->type], pkt->u.size);
+		break;
+
+	case VSOCK_PACKET_TYPE_OFFER:
+	case VSOCK_PACKET_TYPE_ATTACH:
+		written = snprintf(cur, left, ", %s, handle = %u:%u",
+				   type_strings[pkt->type],
+				   pkt->u.handle.context,
+				   pkt->u.handle.resource);
+		break;
+
+	case VSOCK_PACKET_TYPE_WROTE:
+	case VSOCK_PACKET_TYPE_READ:
+	case VSOCK_PACKET_TYPE_RST:
+		written = snprintf(cur, left, ", %s", type_strings[pkt->type]);
+		break;
+	case VSOCK_PACKET_TYPE_SHUTDOWN: {
+		bool recv;
+		bool send;
+
+		recv = pkt->u.mode & RCV_SHUTDOWN;
+		send = pkt->u.mode & SEND_SHUTDOWN;
+		written = snprintf(cur, left, ", %s, mode = %c%c",
+				   type_strings[pkt->type],
+				   recv ? 'R' : ' ', send ? 'S' : ' ');
+	}
+	break;
+
+	case VSOCK_PACKET_TYPE_WAITING_WRITE:
+	case VSOCK_PACKET_TYPE_WAITING_READ:
+		written = snprintf(cur, left,
+			", %s, generation = %" FMT64 "u, offset = %" FMT64 "u",
+			type_strings[pkt->type],
+			pkt->u.wait.generation, pkt->u.wait.offset);
+
+		break;
+
+	case VSOCK_PACKET_TYPE_REQUEST2:
+	case VSOCK_PACKET_TYPE_NEGOTIATE2:
+		written = snprintf(cur, left,
+				   ", %s, size = %" FMT64 "u, proto = %u",
+				   type_strings[pkt->type], pkt->u.size,
+				   pkt->proto);
+		break;
+
+	default:
+		written = snprintf(cur, left, ", unrecognized type");
+	}
+
+	if (written >= left)
+		goto error;
+
+	left -= written;
+	cur += written;
+
+	written = snprintf(cur, left, "  [%s:%u]\n", function, line);
+	if (written >= left)
+		goto error;
+
+	return;
+
+error:
+	pr_err("could not log packet\n");
+}
+
+void vsock_vmci_init_tables(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
+		INIT_LIST_HEAD(&vsock_bind_table[i]);
+
+	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
+		INIT_LIST_HEAD(&vsock_connected_table[i]);
+}
+
+void __vsock_vmci_insert_bound(struct list_head *list, struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+	sock_hold(sk);
+	list_add(&vsk->bound_table, list);
+}
+
+void __vsock_vmci_insert_connected(struct list_head *list, struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+	sock_hold(sk);
+	list_add(&vsk->connected_table, list);
+}
+
+void __vsock_vmci_remove_bound(struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk;
+
+	vsk = vsock_sk(sk);
+
+	list_del_init(&vsk->bound_table);
+	sock_put(sk);
+}
+
+void __vsock_vmci_remove_connected(struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk;
+
+	vsk = vsock_sk(sk);
+
+	list_del_init(&vsk->connected_table);
+	sock_put(sk);
+}
+
+struct sock *__vsock_vmci_find_bound_socket(struct sockaddr_vm *addr)
+{
+	struct vsock_vmci_sock *vsk;
+
+	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
+		if (vsock_addr_equals_addr_any(addr, &vsk->local_addr))
+			return sk_vsock(vsk);
+	}
+
+	return NULL;
+}
+
+struct sock *__vsock_vmci_find_connected_socket(struct sockaddr_vm *src,
+						struct sockaddr_vm *dst)
+{
+	struct vsock_vmci_sock *vsk;
+
+	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
+			    connected_table) {
+		if (vsock_addr_equals_addr(src, &vsk->remote_addr)
+		    && vsock_addr_equals_addr(dst, &vsk->local_addr)) {
+			return sk_vsock(vsk);
+		}
+	}
+
+	return NULL;
+}
+
+bool __vsock_vmci_in_bound_table(struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+	return !list_empty(&vsk->bound_table);
+}
+
+bool __vsock_vmci_in_connected_table(struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+	return !list_empty(&vsk->connected_table);
+}
+
+struct sock *vsock_vmci_get_pending(struct sock *listener,
+				    struct vsock_packet *pkt)
+{
+	struct vsock_vmci_sock *vlistener;
+	struct vsock_vmci_sock *vpending;
+	struct sock *pending;
+
+	vlistener = vsock_sk(listener);
+
+	list_for_each_entry(vpending, &vlistener->pending_links,
+			    pending_links) {
+		struct sockaddr_vm src;
+		struct sockaddr_vm dst;
+
+		vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
+		vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);
+
+		if (vsock_addr_equals_addr(&src, &vpending->remote_addr) &&
+		    vsock_addr_equals_addr(&dst, &vpending->local_addr)) {
+			pending = sk_vsock(vpending);
+			sock_hold(pending);
+			goto found;
+		}
+	}
+
+	pending = NULL;
+found:
+	return pending;
+
+}
+
+void vsock_vmci_release_pending(struct sock *pending)
+{
+	sock_put(pending);
+}
+
+void vsock_vmci_add_pending(struct sock *listener, struct sock *pending)
+{
+	struct vsock_vmci_sock *vlistener;
+	struct vsock_vmci_sock *vpending;
+
+	vlistener = vsock_sk(listener);
+	vpending = vsock_sk(pending);
+
+	sock_hold(pending);
+	sock_hold(listener);
+	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
+}
+
+void vsock_vmci_remove_pending(struct sock *listener, struct sock *pending)
+{
+	struct vsock_vmci_sock *vpending = vsock_sk(pending);
+
+	list_del_init(&vpending->pending_links);
+	sock_put(listener);
+	sock_put(pending);
+}
+
+void vsock_vmci_enqueue_accept(struct sock *listener, struct sock *connected)
+{
+	struct vsock_vmci_sock *vlistener;
+	struct vsock_vmci_sock *vconnected;
+
+	vlistener = vsock_sk(listener);
+	vconnected = vsock_sk(connected);
+
+	sock_hold(connected);
+	sock_hold(listener);
+	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
+}
+
+struct sock *vsock_vmci_dequeue_accept(struct sock *listener)
+{
+	struct vsock_vmci_sock *vlistener;
+	struct vsock_vmci_sock *vconnected;
+
+	vlistener = vsock_sk(listener);
+
+	if (list_empty(&vlistener->accept_queue))
+		return NULL;
+
+	vconnected = list_entry(vlistener->accept_queue.next,
+				struct vsock_vmci_sock, accept_queue);
+
+	list_del_init(&vconnected->accept_queue);
+	sock_put(listener);
+	/* The caller will need a reference on the connected socket so we let
+	 * it call sock_put().
+	 */
+
+	return sk_vsock(vconnected);
+}
+
+void vsock_vmci_remove_accept(struct sock *listener, struct sock *connected)
+{
+	struct vsock_vmci_sock *vconnected;
+
+	if (!vsock_vmci_in_accept_queue(connected))
+		return;
+
+	vconnected = vsock_sk(connected);
+
+	list_del_init(&vconnected->accept_queue);
+	sock_put(listener);
+	sock_put(connected);
+}
+
+bool vsock_vmci_in_accept_queue(struct sock *sk)
+{
+	/* If our accept queue isn't empty, it means we're linked into some
+	 * listener socket's accept queue.
+	 */
+	return !vsock_vmci_is_accept_queue_empty(sk);
+}
+
+bool vsock_vmci_is_accept_queue_empty(struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk = vsock_sk(sk);
+	return list_empty(&vsk->accept_queue);
+}
+
+bool vsock_vmci_is_pending(struct sock *sk)
+{
+	struct vsock_vmci_sock *vsk = vsock_sk(sk);
+	return !list_empty(&vsk->pending_links);
+}
diff --git a/net/vmw_vsock/util.h b/net/vmw_vsock/util.h
new file mode 100644
index 0000000..aef5da3
--- /dev/null
+++ b/net/vmw_vsock/util.h
@@ -0,0 +1,187 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2007-2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef __UTIL_H__
+#define __UTIL_H__
+
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/stddef.h>
+#include <net/sock.h>
+
+#include "vsock_common.h"
+#include "vsock_packet.h"
+
+/* Each bound VSocket is stored in the bind hash table and each connected
+ * VSocket is stored in the connected hash table.
+ *
+ * Unbound sockets are all put on the same list attached to the end of the hash
+ * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
+ * the bucket that their local address hashes to (vsock_bound_sockets(addr)
+ * represents the list that addr hashes to).
+ *
+ * Specifically, we initialize the vsock_bind_table array to a size of
+ * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
+ * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
+ * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
+ * mods with VSOCK_HASH_SIZE - 1 to ensure this.
+ */
+#define VSOCK_HASH_SIZE         251
+#define LAST_RESERVED_PORT      1023
+#define MAX_PORT_RETRIES        24
+
+extern struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
+extern struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
+
+extern spinlock_t vsock_table_lock;
+
+#define VSOCK_HASH(addr)        ((addr)->svm_port % (VSOCK_HASH_SIZE - 1))
+#define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
+#define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
+
+/* XXX This can probably be implemented in a better way. */
+#define VSOCK_CONN_HASH(src, dst)				\
+	(((src)->svm_cid ^ (dst)->svm_port) % (VSOCK_HASH_SIZE - 1))
+#define vsock_connected_sockets(src, dst)		\
+	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
+#define vsock_connected_sockets_vsk(vsk)				\
+	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
+
+void vsock_vmci_log_pkt(char const *function, u32 line,
+			struct vsock_packet *pkt);
+
+void vsock_vmci_init_tables(void);
+void __vsock_vmci_insert_bound(struct list_head *list, struct sock *sk);
+void __vsock_vmci_insert_connected(struct list_head *list, struct sock *sk);
+void __vsock_vmci_remove_bound(struct sock *sk);
+void __vsock_vmci_remove_connected(struct sock *sk);
+struct sock *__vsock_vmci_find_bound_socket(struct sockaddr_vm *addr);
+struct sock *__vsock_vmci_find_connected_socket(struct sockaddr_vm *src,
+						struct sockaddr_vm *dst);
+bool __vsock_vmci_in_bound_table(struct sock *sk);
+bool __vsock_vmci_in_connected_table(struct sock *sk);
+
+struct sock *vsock_vmci_get_pending(struct sock *listener,
+				    struct vsock_packet *pkt);
+void vsock_vmci_release_pending(struct sock *pending);
+void vsock_vmci_add_pending(struct sock *listener, struct sock *pending);
+void vsock_vmci_remove_pending(struct sock *listener, struct sock *pending);
+void vsock_vmci_enqueue_accept(struct sock *listener, struct sock *connected);
+struct sock *vsock_vmci_dequeue_accept(struct sock *listener);
+void vsock_vmci_remove_accept(struct sock *listener, struct sock *connected);
+bool vsock_vmci_in_accept_queue(struct sock *sk);
+bool vsock_vmci_is_accept_queue_empty(struct sock *sk);
+bool vsock_vmci_is_pending(struct sock *sk);
+
+static inline void vsock_vmci_insert_bound(struct list_head *list,
+					   struct sock *sk);
+static inline void vsock_vmci_insert_connected(struct list_head *list,
+					       struct sock *sk);
+static inline void vsock_vmci_remove_bound(struct sock *sk);
+static inline void vsock_vmci_remove_connected(struct sock *sk);
+static inline struct sock *vsock_vmci_find_bound_socket(struct sockaddr_vm
+							*addr);
+static inline struct sock *vsock_vmci_find_connected_socket(struct sockaddr_vm
+							    *src,
+							    struct sockaddr_vm
+							    *dst);
+static inline bool vsock_vmci_in_bound_table(struct sock *sk);
+static inline bool vsock_vmci_in_connected_table(struct sock *sk);
+
+static inline void
+vsock_vmci_insert_bound(struct list_head *list, struct sock *sk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_vmci_insert_bound(list, sk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+
+static inline void
+vsock_vmci_insert_connected(struct list_head *list, struct sock *sk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_vmci_insert_connected(list, sk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+
+static inline void vsock_vmci_remove_bound(struct sock *sk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_vmci_remove_bound(sk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+
+static inline void vsock_vmci_remove_connected(struct sock *sk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_vmci_remove_connected(sk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+
+static inline struct sock *vsock_vmci_find_bound_socket(struct sockaddr_vm
+							*addr)
+{
+	struct sock *sk;
+
+	spin_lock_bh(&vsock_table_lock);
+	sk = __vsock_vmci_find_bound_socket(addr);
+	if (sk)
+		sock_hold(sk);
+
+	spin_unlock_bh(&vsock_table_lock);
+
+	return sk;
+}
+
+static inline struct sock *vsock_vmci_find_connected_socket(struct sockaddr_vm
+							    *src,
+							    struct sockaddr_vm
+							    *dst)
+{
+	struct sock *sk;
+
+	spin_lock_bh(&vsock_table_lock);
+	sk = __vsock_vmci_find_connected_socket(src, dst);
+	if (sk)
+		sock_hold(sk);
+
+	spin_unlock_bh(&vsock_table_lock);
+
+	return sk;
+}
+
+static inline bool vsock_vmci_in_bound_table(struct sock *sk)
+{
+	bool ret;
+
+	spin_lock_bh(&vsock_table_lock);
+	ret = __vsock_vmci_in_bound_table(sk);
+	spin_unlock_bh(&vsock_table_lock);
+
+	return ret;
+}
+
+static inline bool vsock_vmci_in_connected_table(struct sock *sk)
+{
+	bool ret;
+
+	spin_lock_bh(&vsock_table_lock);
+	ret = __vsock_vmci_in_connected_table(sk);
+	spin_unlock_bh(&vsock_table_lock);
+
+	return ret;
+}
+
+#endif /* __UTIL_H__ */