On Sun, Jul 28, 2024 at 11:52:54AM GMT, Amery Hung wrote:

On Tue, Jul 23, 2024 at 7:40 AM Stefano Garzarella [off-list ref] wrote:

quoted

On Wed, Jul 10, 2024 at 09:25:45PM GMT, Amery Hung wrote:

quoted

From: Bobby Eshleman <redacted>

This commit makes the bind table management functions in vsock usable
for different bind tables. Future work will introduce a new table for
datagrams to avoid address collisions, and these functions will be used
there.

Signed-off-by: Bobby Eshleman <redacted>
---
net/vmw_vsock/af_vsock.c | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index acc15e11700c..d571be9cdbf0 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c

@@ -232,11 +232,12 @@ static void __vsock_remove_connected(struct vsock_sock *vsk)
      sock_put(&vsk->sk);

}

-static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
+static struct sock *vsock_find_bound_socket_common(struct sockaddr_vm *addr,
+                                                 struct list_head *bind_table)
{
      struct vsock_sock *vsk;

-      list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
+      list_for_each_entry(vsk, bind_table, bound_table) {
              if (vsock_addr_equals_addr(addr, &vsk->local_addr))
                      return sk_vsock(vsk);

@@ -249,6 +250,11 @@ static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
      return NULL;

}

+static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
+{
+      return vsock_find_bound_socket_common(addr, vsock_bound_sockets(addr));
+}
+
static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
                                                struct sockaddr_vm *dst)
{

@@ -671,12 +677,18 @@ static void vsock_pending_work(struct work_struct *work)

/**** SOCKET OPERATIONS ****/

-static int __vsock_bind_connectible(struct vsock_sock *vsk,
-                                  struct sockaddr_vm *addr)
+static int vsock_bind_common(struct vsock_sock *vsk,
+                           struct sockaddr_vm *addr,
+                           struct list_head *bind_table,
+                           size_t table_size)
{
      static u32 port;
      struct sockaddr_vm new_addr;

+      if (WARN_ONCE(table_size < VSOCK_HASH_SIZE,
+                    "table size too small, may cause overflow"))
+              return -EINVAL;
+

I'd add this in another commit.

quoted

      if (!port)
              port = get_random_u32_above(LAST_RESERVED_PORT);

@@ -692,7 +704,8 @@ static int __vsock_bind_connectible(struct

vsock_sock *vsk,

                      new_addr.svm_port = port++;

-                      if (!__vsock_find_bound_socket(&new_addr)) {
+                      if (!vsock_find_bound_socket_common(&new_addr,
+                                                          &bind_table[VSOCK_HASH(addr)])) {

Can we add a macro for `&bind_table[VSOCK_HASH(addr)])` ?

Definitely. I will add the following macro:

#define vsock_bound_sockets_in_table(bind_table, addr) \
       (&bind_table[VSOCK_HASH(addr)])

yeah.

quoted

quoted

                              found = true;
                              break;
                      }

@@ -709,7 +722,8 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
                      return -EACCES;
              }

-              if (__vsock_find_bound_socket(&new_addr))
+              if (vsock_find_bound_socket_common(&new_addr,
+                                                 &bind_table[VSOCK_HASH(addr)]))
                      return -EADDRINUSE;
      }

@@ -721,11 +735,17 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
       * by AF_UNIX.
       */
      __vsock_remove_bound(vsk);
-      __vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
+      __vsock_insert_bound(&bind_table[VSOCK_HASH(&vsk->local_addr)], vsk);

      return 0;

}

+static int __vsock_bind_connectible(struct vsock_sock *vsk,
+                                  struct sockaddr_vm *addr)
+{
+      return vsock_bind_common(vsk, addr, vsock_bind_table, VSOCK_HASH_SIZE + 1);

What about using ARRAY_SIZE(x) ?

BTW we are using that size just to check it, but all the arrays we use
are statically allocated, so what about a compile time check like
BUILD_BUG_ON()?

I will remove the table_size check you mentioned earlier and the
argument here as the arrays are allocated statically like you
mentioned.

If you think this check may be a good addition, I can add a
BUILD_BUG_ON() in the new vsock_bound_sockets_in_table() macro.

If you want to add it, we need to do it in a separate commit. But since 
we already have so many changes and both arrays are statically allocated 
in the same file, IMHO we can avoid the check.

Stefano