From 28cd29d99fe6d1a54c8dad04854bda10743737d3 Mon Sep 17 00:00:00 2001
From: Ken Brown <kbrown@cornell.edu>
Date: Sat, 2 Jul 2022 15:12:40 -0400
Subject: [PATCH] Cygwin: implement getfacl(1) for socket files

Do this by defining the acl_get method for the fhandler_socket_local
and fhandler_socket_unix classes.  Also define acl_set for these
classes.

Partially addresses: https://cygwin.com/pipermail/cygwin/2022-July/251768.html
---
 winsup/cygwin/fhandler.h      |  4 ++
 winsup/cygwin/release/3.3.6   |  3 ++
 winsup/cygwin/sec_posixacl.cc | 76 +++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index d5ec56a6d..cb5e08fa3 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -861,6 +861,8 @@ class fhandler_socket_local: public fhandler_socket_wsock
   int fchmod (mode_t newmode);
   int fchown (uid_t newuid, gid_t newgid);
   int facl (int, int, struct acl *);
+  struct __acl_t *acl_get (uint32_t);
+  int acl_set (struct __acl_t *, uint32_t);
   int link (const char *);
 
   /* from here on: CLONING */
@@ -1143,6 +1145,8 @@ class fhandler_socket_unix : public fhandler_socket
   int fchmod (mode_t newmode);
   int fchown (uid_t newuid, gid_t newgid);
   int facl (int, int, struct acl *);
+  struct __acl_t *acl_get (uint32_t);
+  int acl_set (struct __acl_t *, uint32_t);
   int link (const char *);
 
   /* select.cc */
diff --git a/winsup/cygwin/release/3.3.6 b/winsup/cygwin/release/3.3.6
index 44a7bcf9d..b18691428 100644
--- a/winsup/cygwin/release/3.3.6
+++ b/winsup/cygwin/release/3.3.6
@@ -26,3 +26,6 @@ Bug Fixes
 - Fix a console problem that the text longer than 1024 bytes cannot
   be pasted correctly.
   Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251764.html
+
+- Don't error out if getfacl(1) is called on a socket file.
+  Partially addresses: https://cygwin.com/pipermail/cygwin/2022-July/251768.html
diff --git a/winsup/cygwin/sec_posixacl.cc b/winsup/cygwin/sec_posixacl.cc
index e7e5a9c3e..c2daa3309 100644
--- a/winsup/cygwin/sec_posixacl.cc
+++ b/winsup/cygwin/sec_posixacl.cc
@@ -633,6 +633,44 @@ fhandler_disk_file::acl_get (acl_type_t type)
   return acl;
 }
 
+acl_t
+fhandler_socket_local::acl_get (acl_type_t type)
+{
+  if (!dev ().isfs ())
+    /* acl_get_fd on a socket. */
+    return fhandler_base::acl_get (type);
+
+  /* acl_get_fd on a socket opened with O_PATH or acl_get_file on a
+     socket file. */
+  if (get_flags () & O_PATH)
+    {
+      set_errno (EBADF);
+      return NULL;
+    }
+  fhandler_disk_file fh (pc);
+  return fh.acl_get (type);
+}
+
+#ifdef __WITH_AF_UNIX
+acl_t
+fhandler_socket_unix::acl_get (acl_type_t type)
+{
+  if (!dev ().isfs ())
+    /* acl_get_fd on a socket. */
+    return fhandler_base::acl_get (type);
+
+  /* acl_get_fd on a socket opened with O_PATH or acl_get_file on a
+     socket file. */
+  if (get_flags () & O_PATH)
+    {
+      set_errno (EBADF);
+      return NULL;
+    }
+  fhandler_disk_file fh (pc);
+  return fh.acl_get (type);
+}
+#endif
+
 extern "C" acl_t
 acl_get_fd (int fd)
 {
@@ -765,6 +803,44 @@ fhandler_disk_file::acl_set (acl_t acl, acl_type_t type)
   return ret;
 }
 
+int
+fhandler_socket_local::acl_set (acl_t acl, acl_type_t type)
+{
+  if (!dev ().isfs ())
+    /* acl_set_fd on a socket. */
+    return fhandler_base::acl_set (acl, type);
+
+  /* acl_set_fd on a socket opened with O_PATH or acl_set_file on a
+     socket file. */
+  if (get_flags () & O_PATH)
+    {
+      set_errno (EBADF);
+      return -1;
+    }
+  fhandler_disk_file fh (pc);
+  return fh.acl_set (acl, type);
+}
+
+#ifdef __WITH_AF_UNIX
+int
+fhandler_socket_unix::acl_set (acl_t acl, acl_type_t type)
+{
+  if (!dev ().isfs ())
+    /* acl_set_fd on a socket. */
+    return fhandler_base::acl_set (acl, type);
+
+  /* acl_set_fd on a socket opened with O_PATH or acl_set_file on a
+     socket file. */
+  if (get_flags () & O_PATH)
+    {
+      set_errno (EBADF);
+      return -1;
+    }
+  fhandler_disk_file fh (pc);
+  return fh.acl_set (acl, type);
+}
+#endif
+
 extern "C" int
 acl_set_fd (int fd, acl_t acl)
 {
-- 
2.36.1