[linux-cifs-client] [DFS support patchset: ] [1/5]: Upcall
implementation for resolving server name to ip via keyctl API
Q (Igor Mammedov)
qwerty0987654321 at mail.ru
Tue Dec 18 14:15:22 GMT 2007
Adds additional option CIFS_DFS_UPCALL to fs/Kconfig for enabling
DFS support.
Resolved IP address is saved as a string in the key payload.
Signed-off-by: Igor Mammedov <niallain at gmail.com>
---
fs/Kconfig | 10 ++++
fs/cifs/Makefile | 2 +
fs/cifs/cifs_dfs_ref.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/cifs_dfs_ref.h | 29 +++++++++++
fs/cifs/cifsfs.c | 15 ++++++-
5 files changed, 176 insertions(+), 1 deletions(-)
create mode 100644 fs/cifs/cifs_dfs_ref.c
create mode 100644 fs/cifs/cifs_dfs_ref.h
diff --git a/fs/Kconfig b/fs/Kconfig
index 635f3e2..0ffa70d 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -2024,6 +2024,16 @@ config CIFS_UPCALL
(for which more secure Kerberos authentication is required). If
unsure, say N.
+config CIFS_DFS_UPCALL
+ bool "DFS feature support (EXPERIMENTAL)"
+ depends on CIFS_EXPERIMENTAL
+ depends on KEYS
+ help
+ Enables an upcall mechanism for CIFS which will be used to contact
+ userspace helper utilities to provide server name resolving which
+ we are needed for implicit mounts of DFS junction points. If
+ unsure, say N.
+
config NCP_FS
tristate "NCP file system support (to mount NetWare volumes)"
depends on IPX!=n || INET
diff --git a/fs/cifs/Makefile b/fs/cifs/Makefile
index 45e42fb..d26c131 100644
--- a/fs/cifs/Makefile
+++ b/fs/cifs/Makefile
@@ -9,3 +9,5 @@ cifs-y := cifsfs.o cifssmb.o cifs_debug.o connect.o dir.o file.o inode.o \
readdir.o ioctl.o sess.o export.o cifsacl.o
cifs-$(CONFIG_CIFS_UPCALL) += cifs_spnego.o
+
+cifs-$(CONFIG_CIFS_DFS_UPCALL) += cifs_dfs_ref.o
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
new file mode 100644
index 0000000..30b0ed1
--- /dev/null
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -0,0 +1,121 @@
+/*
+ * fs/cifs/cifs_dfs_ref.c
+ *
+ * Copyright (c) 2007 Igor Mammedov
+ * Author(s): Igor Mammedov (niallain at gmail.com)
+ *
+ * Contains the CIFS DFS upcall routines
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <keys/user-type.h>
+#include <linux/key-type.h>
+#include "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+
+static int cifs_resolver_instantiate(struct key *key, const void *data,
+ size_t datalen)
+{
+ int rc = 0;
+ char *ip;
+
+ ip = kmalloc(datalen+1, GFP_KERNEL);
+ if (!ip)
+ return -ENOMEM;
+
+ memcpy(ip, data, datalen);
+ ip[datalen] = '\0';
+
+ rcu_assign_pointer(key->payload.data, ip);
+
+ return rc;
+}
+
+struct key_type key_type_cifs_resolver = {
+ .name = "cifs.resolver",
+ .def_datalen = sizeof(struct in_addr),
+ .describe = user_describe,
+ .instantiate = cifs_resolver_instantiate,
+ .match = user_match,
+};
+
+
+/* Resolves server name to ip address.
+ * input:
+ * unc - server UNC
+ * output:
+ * *ip_addr - pointer to server ip, caller responcible for freeing it.
+ * return 0 on success
+ */
+static int
+cifs_resolve_server_name_to_ip(const char *unc, char **ip_addr) {
+ int rc = -EAGAIN;
+ struct key *rkey;
+ char *name;
+ int len;
+
+ if ((!ip_addr) || (!unc))
+ return -EINVAL;
+
+ /* search for server name delimiter */
+ len = strlen(unc);
+ if (len < 3) {
+ cFYI(1, ("%s: unc is too short: %s", __FUNCTION__, unc));
+ return -EINVAL;
+ }
+ len -= 2;
+ name = memchr(unc+2, '\\', len);
+ if (!name) {
+ cFYI(1, ("%s: probably server name is whole unc: %s",
+ __FUNCTION__, unc));
+ } else {
+ len = (name - unc) - 2/* leading // */;
+ }
+
+ name = kmalloc(len+1, GFP_KERNEL);
+ if (!name) {
+ rc = -ENOMEM;
+ return rc;
+ }
+ memcpy(name, unc+2, len);
+ name[len] = 0;
+
+ rkey = request_key(&key_type_cifs_resolver, name, "");
+ if (!IS_ERR(rkey)) {
+ len = strlen(rkey->payload.data);
+ *ip_addr = kmalloc(len+1, GFP_KERNEL);
+ if (*ip_addr) {
+ memcpy(*ip_addr, rkey->payload.data, len);
+ (*ip_addr)[len] = '\0';
+ cFYI(1, ("%s: resolved: %s to %s", __FUNCTION__,
+ rkey->description,
+ *ip_addr
+ ));
+ rc = 0;
+ } else {
+ rc = -ENOMEM;
+ }
+ key_put(rkey);
+ } else {
+ cERROR(1, ("%s: unable to resolve: %s", __FUNCTION__, name));
+ }
+
+ kfree(name);
+ return rc;
+}
+
+
diff --git a/fs/cifs/cifs_dfs_ref.h b/fs/cifs/cifs_dfs_ref.h
new file mode 100644
index 0000000..312a0bb
--- /dev/null
+++ b/fs/cifs/cifs_dfs_ref.h
@@ -0,0 +1,29 @@
+/*
+ * fs/cifs/cifs_dfs_ref.h -- DNS Resolver upcall management for CIFS DFS
+ *
+ * Copyright (c) 2007 Igor Mammedov.
+ * Author(s): Igor Mammedov (niallain at gmail.com)
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _CIFS_DFS_REF_H
+#define _CIFS_DFS_REF_H
+
+#ifdef __KERNEL__
+extern struct key_type key_type_cifs_resolver;
+#endif /* KERNEL */
+
+#endif /* _CIFS_DFS_REF_H */
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 093beaa..8e81717 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -45,6 +45,7 @@
#include <linux/mm.h>
#include <linux/key-type.h>
#include "cifs_spnego.h"
+#include "cifs_dfs_ref.h"
#define CIFS_MAGIC_NUMBER 0xFF534D42 /* the first four bytes of SMB PDUs */
#ifdef CONFIG_CIFS_QUOTA
@@ -1015,11 +1016,16 @@ init_cifs(void)
if (rc)
goto out_unregister_filesystem;
#endif
+#ifdef CONFIG_CIFS_DFS_UPCALL
+ rc = register_key_type(&key_type_cifs_resolver);
+ if (rc)
+ goto out_unregister_key_type;
+#endif
oplockThread = kthread_run(cifs_oplock_thread, NULL, "cifsoplockd");
if (IS_ERR(oplockThread)) {
rc = PTR_ERR(oplockThread);
cERROR(1, ("error %d create oplock thread", rc));
- goto out_unregister_key_type;
+ goto out_unregister_dfs_key_type;
}
dnotifyThread = kthread_run(cifs_dnotify_thread, NULL, "cifsdnotifyd");
@@ -1033,7 +1039,11 @@ init_cifs(void)
out_stop_oplock_thread:
kthread_stop(oplockThread);
+ out_unregister_dfs_key_type:
+#ifdef CONFIG_CIFS_DFS_UPCALL
+ unregister_key_type(&key_type_cifs_resolver);
out_unregister_key_type:
+#endif
#ifdef CONFIG_CIFS_UPCALL
unregister_key_type(&cifs_spnego_key_type);
out_unregister_filesystem:
@@ -1059,6 +1069,9 @@ exit_cifs(void)
#ifdef CONFIG_PROC_FS
cifs_proc_clean();
#endif
+#ifdef CONFIG_CIFS_DFS_UPCALL
+ unregister_key_type(&key_type_cifs_resolver);
+#endif
#ifdef CONFIG_CIFS_UPCALL
unregister_key_type(&cifs_spnego_key_type);
#endif
--
1.5.3.7
More information about the linux-cifs-client
mailing list