From 9b64495c6cd22cd65f118c18a36b2de7cbde4344 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sun, 5 Jul 2020 17:09:58 +0200
Subject: pflocal: support SO_SNDBUF for unconnected sockets

We can store the requested value, to be applied when we connect the
sockets.

* pflocal/sock.h (struct sock): Add req_write_limit field.
* pflocal/sock.c (sock_create): Initialize req_write_limit field to 0.
(sock_connect): Bump the write_limit of the write pipe to the
req_write_limit value.
(sock_shutdown): Update req_write_limit from the write_limit of the
write pipe.
* pflocal/socket.c (S_socket_getopt, S_socket_setopt): When write_pipe
is NULL, use req_write_limit.
---
 pflocal/sock.c   |  5 +++++
 pflocal/sock.h   |  3 +++
 pflocal/socket.c | 12 +++++-------
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/pflocal/sock.c b/pflocal/sock.c
index be64a3da..89ba16e2 100644
--- a/pflocal/sock.c
+++ b/pflocal/sock.c
@@ -116,6 +116,7 @@ sock_create (struct pipe_class *pipe_class, mode_t mode, struct sock **sock)
   new->refs = 0;
   new->flags = 0;
   new->write_pipe = NULL;
+  new->req_write_limit = 0;
   new->mode = mode;
   new->id = MACH_PORT_NULL;
   new->listen_queue = NULL;
@@ -397,6 +398,8 @@ sock_connect (struct sock *sock1, struct sock *sock2)
 	  assert_backtrace (pipe);	/* Since PFLOCAL_SOCK_SHUTDOWN_READ isn't set.  */
 	  pipe_add_writer (pipe);
 	  wr->write_pipe = pipe;
+	  if (pipe->write_limit < wr->req_write_limit)
+	    pipe->write_limit = wr->req_write_limit;
 	}
     }
 
@@ -474,6 +477,8 @@ sock_shutdown (struct sock *sock, unsigned flags)
       /* Shutdown the write half.  */
       write_pipe = sock->write_pipe;
       sock->write_pipe = NULL;
+      if (write_pipe)
+	sock->req_write_limit = write_pipe->write_limit;
     }
 
   /* Unlock SOCK here, as we may subsequently wake up other threads. */
diff --git a/pflocal/sock.h b/pflocal/sock.h
index dca16755..c1e73f9b 100644
--- a/pflocal/sock.h
+++ b/pflocal/sock.h
@@ -52,6 +52,9 @@ struct sock
      another socket.  */
   struct pipe *read_pipe, *write_pipe;
 
+  /* The write limit that this side would like write_pipe to support.  */
+  size_t req_write_limit;
+
   /* FLAGS from SOCK_*, below.  */
   unsigned flags;
 
diff --git a/pflocal/socket.c b/pflocal/socket.c
index 8f90da2d..89444370 100644
--- a/pflocal/socket.c
+++ b/pflocal/socket.c
@@ -479,12 +479,10 @@ S_socket_getopt (struct sock_user *user,
 	      break;
 	    }
 	  pipe = sock->write_pipe;
-	  if (!pipe)
-	    {
-	      ret = ENOTCONN;
-	      break;
-	    }
-	  *(int *)*value = pipe->write_limit;
+	  if (pipe)
+	    *(int *)*value = pipe->write_limit;
+	  else
+	    *(int *)*value = sock->req_write_limit;
 	  *value_len = sizeof (int);
 	  break;
 	case SO_ERROR:
@@ -594,7 +592,7 @@ S_socket_setopt (struct sock_user *user,
 	    pipe = sock->write_pipe;
 	    if (!pipe)
 	      {
-		ret = ENOTCONN;
+		sock->req_write_limit = new;
 		break;
 	      }
 
-- 
cgit v1.2.3