cifs: send workstation name during ntlmssp session setup

During the ntlmssp session setup (authenticate phases)
send the client workstation info. This can make debugging easier on
servers.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsglob.h

@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/mempool.h>
 #include <linux/workqueue.h>
+#include <linux/utsname.h>
 #include "cifs_fs_sb.h"
 #include "cifsacl.h"
 #include <crypto/internal/hash.h>
@@ -99,6 +100,8 @@
 #define XATTR_DOS_ATTRIB "user.DOSATTRIB"
 #endif
 
+#define CIFS_MAX_WORKSTATION_LEN  (__NEW_UTS_LEN + 1)  /* reasonable max for client */
+
 /*
  * CIFS vfs client Status information (based on what we know.)
  */
@@ -909,6 +912,7 @@ struct cifs_ses {
 				   and after mount option parsing we fill it */
 	char *domainName;
 	char *password;
+	char *workstation_name;
 	struct session_key auth_key;
 	struct ntlmssp_auth *ntlmssp; /* ciphertext, flags, server challenge */
 	enum securityEnum sectype; /* what security flavor was specified? */

fs/cifs/connect.c

@@ -1948,6 +1948,12 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 		if (!ses->domainName)
 			goto get_ses_fail;
 	}
+	if (ctx->workstation_name) {
+		ses->workstation_name = kstrdup(ctx->workstation_name,
+						GFP_KERNEL);
+		if (!ses->workstation_name)
+			goto get_ses_fail;
+	}
 	if (ctx->domainauto)
 		ses->domainAuto = ctx->domainauto;
 	ses->cred_uid = ctx->cred_uid;

fs/cifs/fs_context.c

@@ -309,6 +309,7 @@ smb3_fs_context_dup(struct smb3_fs_context *new_ctx, struct smb3_fs_context *ctx
 	new_ctx->username = NULL;
 	new_ctx->password = NULL;
 	new_ctx->domainname = NULL;
+	new_ctx->workstation_name = NULL;
 	new_ctx->UNC = NULL;
 	new_ctx->source = NULL;
 	new_ctx->iocharset = NULL;
@@ -323,6 +324,7 @@ smb3_fs_context_dup(struct smb3_fs_context *new_ctx, struct smb3_fs_context *ctx
 	DUP_CTX_STR(UNC);
 	DUP_CTX_STR(source);
 	DUP_CTX_STR(domainname);
+	DUP_CTX_STR(workstation_name);
 	DUP_CTX_STR(nodename);
 	DUP_CTX_STR(iocharset);
 
@@ -720,6 +722,11 @@ static int smb3_verify_reconfigure_ctx(struct fs_context *fc,
 		cifs_errorf(fc, "can not change domainname during remount\n");
 		return -EINVAL;
 	}
+	if (new_ctx->workstation_name &&
+	    (!old_ctx->workstation_name || strcmp(new_ctx->workstation_name, old_ctx->workstation_name))) {
+		cifs_errorf(fc, "can not change workstation_name during remount\n");
+		return -EINVAL;
+	}
 	if (new_ctx->nodename &&
 	    (!old_ctx->nodename || strcmp(new_ctx->nodename, old_ctx->nodename))) {
 		cifs_errorf(fc, "can not change nodename during remount\n");
@@ -753,7 +760,8 @@ static int smb3_reconfigure(struct fs_context *fc)
 		return rc;
 
 	/*
-	 * We can not change UNC/username/password/domainname/nodename/iocharset
+	 * We can not change UNC/username/password/domainname/
+	 * workstation_name/nodename/iocharset
 	 * during reconnect so ignore what we have in the new context and
 	 * just use what we already have in cifs_sb->ctx.
 	 */
@@ -762,6 +770,7 @@ static int smb3_reconfigure(struct fs_context *fc)
 	STEAL_STRING(cifs_sb, ctx, username);
 	STEAL_STRING(cifs_sb, ctx, password);
 	STEAL_STRING(cifs_sb, ctx, domainname);
+	STEAL_STRING(cifs_sb, ctx, workstation_name);
 	STEAL_STRING(cifs_sb, ctx, nodename);
 	STEAL_STRING(cifs_sb, ctx, iocharset);
 
@@ -1414,13 +1423,22 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 
 int smb3_init_fs_context(struct fs_context *fc)
 {
+	int rc;
 	struct smb3_fs_context *ctx;
 	char *nodename = utsname()->nodename;
 	int i;
 
 	ctx = kzalloc(sizeof(struct smb3_fs_context), GFP_KERNEL);
-	if (unlikely(!ctx))
-		return -ENOMEM;
+	if (unlikely(!ctx)) {
+		rc = -ENOMEM;
+		goto err_exit;
+	}
+
+	ctx->workstation_name = kstrdup(nodename, GFP_KERNEL);
+	if (unlikely(!ctx->workstation_name)) {
+		rc = -ENOMEM;
+		goto err_exit;
+	}
 
 	/*
 	 * does not have to be perfect mapping since field is
@@ -1493,6 +1511,14 @@ int smb3_init_fs_context(struct fs_context *fc)
 	fc->fs_private = ctx;
 	fc->ops = &smb3_fs_context_ops;
 	return 0;
+
+err_exit:
+	if (ctx) {
+		kfree(ctx->workstation_name);
+		kfree(ctx);
+	}
+
+	return rc;
 }
 
 void
@@ -1518,6 +1544,8 @@ smb3_cleanup_fs_context_contents(struct smb3_fs_context *ctx)
 	ctx->source = NULL;
 	kfree(ctx->domainname);
 	ctx->domainname = NULL;
+	kfree(ctx->workstation_name);
+	ctx->workstation_name = NULL;
 	kfree(ctx->nodename);
 	ctx->nodename = NULL;
 	kfree(ctx->iocharset);

fs/cifs/fs_context.h

@@ -170,6 +170,7 @@ struct smb3_fs_context {
 	char *server_hostname;
 	char *UNC;
 	char *nodename;
+	char *workstation_name;
 	char *iocharset;  /* local code page for mapping to and from Unicode */
 	char source_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* clnt nb name */
 	char target_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* srvr nb name */

fs/cifs/misc.c

@@ -94,6 +94,7 @@ sesInfoFree(struct cifs_ses *buf_to_free)
 	kfree_sensitive(buf_to_free->password);
 	kfree(buf_to_free->user_name);
 	kfree(buf_to_free->domainName);
+	kfree(buf_to_free->workstation_name);
 	kfree_sensitive(buf_to_free->auth_key.response);
 	kfree(buf_to_free->iface_list);
 	kfree_sensitive(buf_to_free);

fs/cifs/ntlmssp.h

@@ -119,7 +119,9 @@ typedef struct _AUTHENTICATE_MESSAGE {
  */
 
 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len, struct cifs_ses *ses);
-void build_ntlmssp_negotiate_blob(unsigned char *pbuffer, struct cifs_ses *ses);
+int build_ntlmssp_negotiate_blob(unsigned char **pbuffer, u16 *buflen,
+				 struct cifs_ses *ses,
+				 const struct nls_table *nls_cp);
 int build_ntlmssp_auth_blob(unsigned char **pbuffer, u16 *buflen,
 			struct cifs_ses *ses,
 			const struct nls_table *nls_cp);