Merge branch 'for-3.10' of git://git.samba.org/sfrench/cifs-2.6

Pull CIFS fixes from Steve French:
 "Fixes for a couple of DFS problems, a problem with extended security
  negotiation and two other small cifs fixes"

* 'for-3.10' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix composing of mount options for DFS referrals
  cifs: stop printing the unc= option in /proc/mounts
  cifs: fix error handling when calling cifs_parse_devname
  cifs: allow sec=none mounts to work against servers that don't support extended security
  cifs: fix potential buffer overrun when composing a new options string
  cifs: only set ops for inodes in I_NEW state

4 files changed, 88 insertions, 83 deletions

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index 8e33ec65847..58df174deb1 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/vfs.h>
 #include <linux/fs.h>
+#include <linux/inet.h>
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifsfs.h"
@@ -48,58 +49,74 @@ void cifs_dfs_release_automount_timer(void)
 }
 
 /**
- * cifs_get_share_name	-	extracts share name from UNC
- * @node_name:	pointer to UNC string
+ * cifs_build_devname - build a devicename from a UNC and optional prepath
+ * @nodename:	pointer to UNC string
+ * @prepath:	pointer to prefixpath (or NULL if there isn't one)
  *
- * Extracts sharename form full UNC.
- * i.e. strips from UNC trailing path that is not part of share
- * name and fixup missing '\' in the beginning of DFS node refferal
- * if necessary.
- * Returns pointer to share name on success or ERR_PTR on error.
- * Caller is responsible for freeing returned string.
+ * Build a new cifs devicename after chasing a DFS referral. Allocate a buffer
+ * big enough to hold the final thing. Copy the UNC from the nodename, and
+ * concatenate the prepath onto the end of it if there is one.
+ *
+ * Returns pointer to the built string, or a ERR_PTR. Caller is responsible
+ * for freeing the returned string.
  */
-static char *cifs_get_share_name(const char *node_name)
+static char *
+cifs_build_devname(char *nodename, const char *prepath)
 {
-	int len;
-	char *UNC;
-	char *pSep;
-
-	len = strlen(node_name);
-	UNC = kmalloc(len+2 /*for term null and additional \ if it's missed */,
-			 GFP_KERNEL);
-	if (!UNC)
-		return ERR_PTR(-ENOMEM);
+	size_t pplen;
+	size_t unclen;
+	char *dev;
+	char *pos;
+
+	/* skip over any preceding delimiters */
+	nodename += strspn(nodename, "\\");
+	if (!*nodename)
+		return ERR_PTR(-EINVAL);
 
-	/* get share name and server name */
-	if (node_name[1] != '\\') {
-		UNC[0] = '\\';
-		strncpy(UNC+1, node_name, len);
-		len++;
-		UNC[len] = 0;
-	} else {
-		strncpy(UNC, node_name, len);
-		UNC[len] = 0;
-	}
+	/* get length of UNC and set pos to last char */
+	unclen = strlen(nodename);
+	pos = nodename + unclen - 1;
 
-	/* find server name end */
-	pSep = memchr(UNC+2, '\\', len-2);
-	if (!pSep) {
-		cifs_dbg(VFS, "%s: no server name end in node name: %s\n",
-			 __func__, node_name);
-		kfree(UNC);
-		return ERR_PTR(-EINVAL);
+	/* trim off any trailing delimiters */
+	while (*pos == '\\') {
+		--pos;
+		--unclen;
 	}
 
-	/* find sharename end */
-	pSep++;
-	pSep = memchr(UNC+(pSep-UNC), '\\', len-(pSep-UNC));
-	if (pSep) {
-		/* trim path up to sharename end
-		 * now we have share name in UNC */
-		*pSep = 0;
+	/* allocate a buffer:
+	 * +2 for preceding "//"
+	 * +1 for delimiter between UNC and prepath
+	 * +1 for trailing NULL
+	 */
+	pplen = prepath ? strlen(prepath) : 0;
+	dev = kmalloc(2 + unclen + 1 + pplen + 1, GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	pos = dev;
+	/* add the initial "//" */
+	*pos = '/';
+	++pos;
+	*pos = '/';
+	++pos;
+
+	/* copy in the UNC portion from referral */
+	memcpy(pos, nodename, unclen);
+	pos += unclen;
+
+	/* copy the prefixpath remainder (if there is one) */
+	if (pplen) {
+		*pos = '/';
+		++pos;
+		memcpy(pos, prepath, pplen);
+		pos += pplen;
 	}
 
-	return UNC;
+	/* NULL terminator */
+	*pos = '\0';
+
+	convert_delimiter(dev, '/');
+	return dev;
 }
 
 
@@ -123,6 +140,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
 {
 	int rc;
 	char *mountdata = NULL;
+	const char *prepath = NULL;
 	int md_len;
 	char *tkn_e;
 	char *srvIP = NULL;
@@ -132,7 +150,10 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
 	if (sb_mountdata == NULL)
 		return ERR_PTR(-EINVAL);
 
-	*devname = cifs_get_share_name(ref->node_name);
+	if (strlen(fullpath) - ref->path_consumed)
+		prepath = fullpath + ref->path_consumed;
+
+	*devname = cifs_build_devname(ref->node_name, prepath);
 	if (IS_ERR(*devname)) {
 		rc = PTR_ERR(*devname);
 		*devname = NULL;
@@ -146,12 +167,14 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
 		goto compose_mount_options_err;
 	}
 
-	/* md_len = strlen(...) + 12 for 'sep+prefixpath='
-	 * assuming that we have 'unc=' and 'ip=' in
-	 * the original sb_mountdata
+	/*
+	 * In most cases, we'll be building a shorter string than the original,
+	 * but we do have to assume that the address in the ip= option may be
+	 * much longer than the original. Add the max length of an address
+	 * string to the length of the original string to allow for worst case.
 	 */
-	md_len = strlen(sb_mountdata) + rc + strlen(ref->node_name) + 12;
-	mountdata = kzalloc(md_len+1, GFP_KERNEL);
+	md_len = strlen(sb_mountdata) + INET6_ADDRSTRLEN;
+	mountdata = kzalloc(md_len + 1, GFP_KERNEL);
 	if (mountdata == NULL) {
 		rc = -ENOMEM;
 		goto compose_mount_options_err;
@@ -195,26 +218,6 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
 		strncat(mountdata, &sep, 1);
 	strcat(mountdata, "ip=");
 	strcat(mountdata, srvIP);
-	strncat(mountdata, &sep, 1);
-	strcat(mountdata, "unc=");
-	strcat(mountdata, *devname);
-
-	/* find & copy prefixpath */
-	tkn_e = strchr(ref->node_name + 2, '\\');
-	if (tkn_e == NULL) {
-		/* invalid unc, missing share name*/
-		rc = -EINVAL;
-		goto compose_mount_options_err;
-	}
-
-	tkn_e = strchr(tkn_e + 1, '\\');
-	if (tkn_e || (strlen(fullpath) - ref->path_consumed)) {
-		strncat(mountdata, &sep, 1);
-		strcat(mountdata, "prefixpath=");
-		if (tkn_e)
-			strcat(mountdata, tkn_e + 1);
-		strcat(mountdata, fullpath + ref->path_consumed);
-	}
 
 	/*cifs_dbg(FYI, "%s: parent mountdata: %s\n", __func__, sb_mountdata);*/
 	/*cifs_dbg(FYI, "%s: submount mountdata: %s\n", __func__, mountdata );*/
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 72e4efee138..3752b9f6d9e 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -372,9 +372,6 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
 	cifs_show_security(s, tcon->ses->server);
 	cifs_show_cache_flavor(s, cifs_sb);
 
-	seq_printf(s, ",unc=");
-	seq_escape(s, tcon->treeName, " \t\n\\");
-
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)
 		seq_printf(s, ",multiuser");
 	else if (tcon->ses->user_name)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 99eeaa17ee0..5b97e56ddbc 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1061,6 +1061,7 @@ static int cifs_parse_security_flavors(char *value,
 #endif
 	case Opt_sec_none:
 		vol->nullauth = 1;
+		vol->secFlg |= CIFSSEC_MAY_NTLM;
 		break;
 	default:
 		cifs_dbg(VFS, "bad security option: %s\n", value);
@@ -1257,14 +1258,18 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 	vol->backupuid_specified = false; /* no backup intent for a user */
 	vol->backupgid_specified = false; /* no backup intent for a group */
 
-	/*
-	 * For now, we ignore -EINVAL errors under the assumption that the
-	 * unc= and prefixpath= options will be usable.
-	 */
-	if (cifs_parse_devname(devname, vol) == -ENOMEM) {
-		printk(KERN_ERR "CIFS: Unable to allocate memory to parse "
-				"device string.\n");
-		goto out_nomem;
+	switch (cifs_parse_devname(devname, vol)) {
+	case 0:
+		break;
+	case -ENOMEM:
+		cifs_dbg(VFS, "Unable to allocate memory for devname.\n");
+		goto cifs_parse_mount_err;
+	case -EINVAL:
+		cifs_dbg(VFS, "Malformed UNC in devname.\n");
+		goto cifs_parse_mount_err;
+	default:
+		cifs_dbg(VFS, "Unknown error parsing devname.\n");
+		goto cifs_parse_mount_err;
 	}
 
 	while ((data = strsep(&options, separator)) != NULL) {
@@ -1826,7 +1831,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 	}
 #endif
 	if (!vol->UNC) {
-		cifs_dbg(VFS, "CIFS mount error: No usable UNC path provided in device string or in unc= option!\n");
+		cifs_dbg(VFS, "CIFS mount error: No usable UNC path provided in device string!\n");
 		goto cifs_parse_mount_err;
 	}
 
diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
index e7512e49761..7ede7306599 100644
--- a/fs/cifs/dns_resolve.c
+++ b/fs/cifs/dns_resolve.c
@@ -34,7 +34,7 @@
 
 /**
  * dns_resolve_server_name_to_ip - Resolve UNC server name to ip address.
- * @unc: UNC path specifying the server
+ * @unc: UNC path specifying the server (with '/' as delimiter)
  * @ip_addr: Where to return the IP address.
  *
  * The IP address will be returned in string form, and the caller is
@@ -64,7 +64,7 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
 	hostname = unc + 2;
 
 	/* Search for server name delimiter */
-	sep = memchr(hostname, '\\', len);
+	sep = memchr(hostname, '/', len);
 	if (sep)
 		len = sep - hostname;
 	else