Minimal libshare infrastructure

ZFS even under Solaris does not strictly require libshare to be
available.  The current implementation attempts to dlopen() the
library to access the needed symbols.  If this fails libshare
support is simply disabled.

This means that on Linux we only need the most minimal libshare
implementation.  In fact just enough to prevent the build from
failing.  Longer term we can decide if we want to implement a
libshare library like Solaris.  At best this would be an abstraction
layer between ZFS and NFS/SMB.  Alternately, we can drop libshare
entirely and directly integrate ZFS with Linux's NFS/SMB.

Finally the bare bones user-libshare.m4 test was dropped.  If we
do decide to implement libshare at some point it will surely be
as part of this package so the check is not needed.

22 files changed, 24 insertions, 49 deletions

diff --git a/lib/Makefile.in b/lib/Makefile.in
index 18ff05229..d607102b1 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -62,7 +62,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libavl/Makefile.in b/lib/libavl/Makefile.in
index 500846a77..91590932a 100644
--- a/lib/libavl/Makefile.in
+++ b/lib/libavl/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libefi/Makefile.in b/lib/libefi/Makefile.in
index 1f4409066..7839c1354 100644
--- a/lib/libefi/Makefile.in
+++ b/lib/libefi/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libnvpair/Makefile.in b/lib/libnvpair/Makefile.in
index e1027d51c..0bafbab1c 100644
--- a/lib/libnvpair/Makefile.in
+++ b/lib/libnvpair/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/Makefile.in b/lib/libspl/Makefile.in
index 385a567c6..8aa947ab4 100644
--- a/lib/libspl/Makefile.in
+++ b/lib/libspl/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/asm-generic/Makefile.in b/lib/libspl/asm-generic/Makefile.in
index 162c386ca..0a8ff7c25 100644
--- a/lib/libspl/asm-generic/Makefile.in
+++ b/lib/libspl/asm-generic/Makefile.in
@@ -63,7 +63,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/asm-i386/Makefile.in b/lib/libspl/asm-i386/Makefile.in
index 9a26bb4d4..6ef74836a 100644
--- a/lib/libspl/asm-i386/Makefile.in
+++ b/lib/libspl/asm-i386/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/asm-x86_64/Makefile.in b/lib/libspl/asm-x86_64/Makefile.in
index a00f235b7..5c1aeafee 100644
--- a/lib/libspl/asm-x86_64/Makefile.in
+++ b/lib/libspl/asm-x86_64/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/Makefile.in b/lib/libspl/include/Makefile.in
index 360560052..0f2a688ae 100644
--- a/lib/libspl/include/Makefile.in
+++ b/lib/libspl/include/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/ia32/Makefile.in b/lib/libspl/include/ia32/Makefile.in
index a9f80cde8..d3a8f6fa2 100644
--- a/lib/libspl/include/ia32/Makefile.in
+++ b/lib/libspl/include/ia32/Makefile.in
@@ -62,7 +62,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/ia32/sys/Makefile.in b/lib/libspl/include/ia32/sys/Makefile.in
index fb0fe3f8c..5f7e05fdd 100644
--- a/lib/libspl/include/ia32/sys/Makefile.in
+++ b/lib/libspl/include/ia32/sys/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/libshare.h b/lib/libspl/include/libshare.h
index afbdf5b05..f1fbfad2b 100644
--- a/lib/libspl/include/libshare.h
+++ b/lib/libspl/include/libshare.h
@@ -23,12 +23,20 @@
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
-
-/*
- * basic API declarations for share management
- */
-
 #ifndef _LIBSPL_LIBSHARE_H
 #define _LIBSPL_LIBSHARE_H
 
+typedef void *sa_handle_t;	/* opaque handle to access core functions */
+typedef void *sa_group_t;
+typedef void *sa_share_t;
+
+/* API Initialization */
+#define	SA_INIT_SHARE_API	0x0001	/* init share specific interface */
+#define	SA_INIT_CONTROL_API	0x0002	/* init control specific interface */
+
+/* Error values */
+#define	SA_OK			0
+#define	SA_NO_MEMORY		2	/* no memory for data structures */
+#define	SA_CONFIG_ERR		6	/* system configuration error */
+
 #endif /* _LIBSPL_LIBSHARE_H */
diff --git a/lib/libspl/include/rpc/Makefile.in b/lib/libspl/include/rpc/Makefile.in
index 1fd162a47..850f04542 100644
--- a/lib/libspl/include/rpc/Makefile.in
+++ b/lib/libspl/include/rpc/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/sys/Makefile.in b/lib/libspl/include/sys/Makefile.in
index 0746ded39..f8f8294d9 100644
--- a/lib/libspl/include/sys/Makefile.in
+++ b/lib/libspl/include/sys/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/sys/dktp/Makefile.in b/lib/libspl/include/sys/dktp/Makefile.in
index 499081af2..19b0f3bcb 100644
--- a/lib/libspl/include/sys/dktp/Makefile.in
+++ b/lib/libspl/include/sys/dktp/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/sys/sysevent/Makefile.in b/lib/libspl/include/sys/sysevent/Makefile.in
index 0a9c6d186..96af2d3b1 100644
--- a/lib/libspl/include/sys/sysevent/Makefile.in
+++ b/lib/libspl/include/sys/sysevent/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libspl/include/util/Makefile.in b/lib/libspl/include/util/Makefile.in
index 27aa363f3..bfaec7a2e 100644
--- a/lib/libspl/include/util/Makefile.in
+++ b/lib/libspl/include/util/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libunicode/Makefile.in b/lib/libunicode/Makefile.in
index 5daee2b73..fb075e8bf 100644
--- a/lib/libunicode/Makefile.in
+++ b/lib/libunicode/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libuutil/Makefile.in b/lib/libuutil/Makefile.in
index 1a28249ae..32d6a7404 100644
--- a/lib/libuutil/Makefile.in
+++ b/lib/libuutil/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libzfs/Makefile.in b/lib/libzfs/Makefile.in
index c8b500466..cad8e6c33 100644
--- a/lib/libzfs/Makefile.in
+++ b/lib/libzfs/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \
diff --git a/lib/libzfs/libzfs_mount.c b/lib/libzfs/libzfs_mount.c
index 75ce3676f..42036a44b 100644
--- a/lib/libzfs/libzfs_mount.c
+++ b/lib/libzfs/libzfs_mount.c
@@ -121,20 +121,21 @@ zfs_share_proto_t share_all_proto[] = {
 };
 
 /*
- * Search the sharetab for the given mountpoint and protocol, returning
+ * Search for NFS and SMB exports for the given mountpoint and protocol, returning
  * a zfs_share_type_t value.
  */
 static zfs_share_type_t
 is_shared(libzfs_handle_t *hdl, const char *mountpoint, zfs_share_proto_t proto)
 {
 	char buf[MAXPATHLEN], *tab;
-	char *ptr;
 
 	if (hdl->libzfs_sharetab == NULL)
 		return (SHARED_NOT_SHARED);
 
 	(void) fseek(hdl->libzfs_sharetab, 0, SEEK_SET);
 
+	/* Search /etc/exports for NFS exports */
+	/* FIXME: Assumes the file is tab delimited. */
 	while (fgets(buf, sizeof (buf), hdl->libzfs_sharetab) != NULL) {
 
 		/* the mountpoint is the first entry on each line */
@@ -143,31 +144,15 @@ is_shared(libzfs_handle_t *hdl, const char *mountpoint, zfs_share_proto_t proto)
 
 		*tab = '\0';
 		if (strcmp(buf, mountpoint) == 0) {
-			/*
-			 * the protocol field is the third field
-			 * skip over second field
-			 */
-			ptr = ++tab;
-			if ((tab = strchr(ptr, '\t')) == NULL)
-				continue;
-			ptr = ++tab;
-			if ((tab = strchr(ptr, '\t')) == NULL)
-				continue;
-			*tab = '\0';
-			if (strcmp(ptr,
-			    proto_table[proto].p_name) == 0) {
-				switch (proto) {
-				case PROTO_NFS:
-					return (SHARED_NFS);
-				case PROTO_SMB:
-					return (SHARED_SMB);
-				default:
-					return (0);
-				}
-			}
+			if (proto == PROTO_NFS)
+				return (SHARED_NFS);
+			else
+				return (SHARED_NOT_SHARED);
 		}
 	}
 
+	/* XXX: Search /etc/samba/smb.conf for SMB exports, return SHARED_SMB */
+
 	return (SHARED_NOT_SHARED);
 }
 
@@ -808,10 +793,12 @@ zfs_share_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto)
 		return (0);
 
 	if ((ret = zfs_init_libshare(hdl, SA_INIT_SHARE_API)) != SA_OK) {
+#ifdef HAVE_SHARE
 		(void) zfs_error_fmt(hdl, EZFS_SHARENFSFAILED,
 		    dgettext(TEXT_DOMAIN, "cannot share '%s': %s"),
 		    zfs_get_name(zhp), _sa_errorstr != NULL ?
 		    _sa_errorstr(ret) : "");
+#endif /* HAVE_SHARE */
 		return (-1);
 	}
 
diff --git a/lib/libzpool/Makefile.in b/lib/libzpool/Makefile.in
index 421e55cc2..209b8594e 100644
--- a/lib/libzpool/Makefile.in
+++ b/lib/libzpool/Makefile.in
@@ -64,7 +64,6 @@ am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/user-frame-larger-than.m4 \
 	$(top_srcdir)/config/user-ioctl.m4 \
 	$(top_srcdir)/config/user-libblkid.m4 \
-	$(top_srcdir)/config/user-libshare.m4 \
 	$(top_srcdir)/config/user-libuuid.m4 \
 	$(top_srcdir)/config/user-nptl_guard_within_stack.m4 \
 	$(top_srcdir)/config/user-selinux.m4 \