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-rw-r--r--fs/cifs/link.c571
1 files changed, 480 insertions, 91 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index fc1e0487eae..68559fd557f 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -20,6 +20,7 @@
*/
#include <linux/fs.h>
#include <linux/stat.h>
+#include <linux/slab.h>
#include <linux/namei.h>
#include "cifsfs.h"
#include "cifspdu.h"
@@ -28,78 +29,465 @@
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
+/*
+ * M-F Symlink Functions - Begin
+ */
+
+#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
+#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
+#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
+#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
+#define CIFS_MF_SYMLINK_FILE_SIZE \
+ (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
+
+#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
+#define CIFS_MF_SYMLINK_MD5_FORMAT \
+ "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
+#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
+ md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
+ md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
+ md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
+ md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
+
+static int
+symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
+{
+ int rc;
+ unsigned int size;
+ struct crypto_shash *md5;
+ struct sdesc *sdescmd5;
+
+ md5 = crypto_alloc_shash("md5", 0, 0);
+ if (IS_ERR(md5)) {
+ rc = PTR_ERR(md5);
+ cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
+ __func__, rc);
+ return rc;
+ }
+ size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
+ sdescmd5 = kmalloc(size, GFP_KERNEL);
+ if (!sdescmd5) {
+ rc = -ENOMEM;
+ goto symlink_hash_err;
+ }
+ sdescmd5->shash.tfm = md5;
+ sdescmd5->shash.flags = 0x0;
+
+ rc = crypto_shash_init(&sdescmd5->shash);
+ if (rc) {
+ cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
+ goto symlink_hash_err;
+ }
+ rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
+ if (rc) {
+ cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
+ goto symlink_hash_err;
+ }
+ rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
+ if (rc)
+ cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
+
+symlink_hash_err:
+ crypto_free_shash(md5);
+ kfree(sdescmd5);
+
+ return rc;
+}
+
+static int
+parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
+ char **_link_str)
+{
+ int rc;
+ unsigned int link_len;
+ const char *md5_str1;
+ const char *link_str;
+ u8 md5_hash[16];
+ char md5_str2[34];
+
+ if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
+ return -EINVAL;
+
+ md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
+ link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
+
+ rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
+ if (rc != 1)
+ return -EINVAL;
+
+ rc = symlink_hash(link_len, link_str, md5_hash);
+ if (rc) {
+ cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
+ return rc;
+ }
+
+ snprintf(md5_str2, sizeof(md5_str2),
+ CIFS_MF_SYMLINK_MD5_FORMAT,
+ CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
+
+ if (strncmp(md5_str1, md5_str2, 17) != 0)
+ return -EINVAL;
+
+ if (_link_str) {
+ *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
+ if (!*_link_str)
+ return -ENOMEM;
+ }
+
+ *_link_len = link_len;
+ return 0;
+}
+
+static int
+format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
+{
+ int rc;
+ unsigned int link_len;
+ unsigned int ofs;
+ u8 md5_hash[16];
+
+ if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
+ return -EINVAL;
+
+ link_len = strlen(link_str);
+
+ if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
+ return -ENAMETOOLONG;
+
+ rc = symlink_hash(link_len, link_str, md5_hash);
+ if (rc) {
+ cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
+ return rc;
+ }
+
+ snprintf(buf, buf_len,
+ CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
+ link_len,
+ CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
+
+ ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
+ memcpy(buf + ofs, link_str, link_len);
+
+ ofs += link_len;
+ if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
+ buf[ofs] = '\n';
+ ofs++;
+ }
+
+ while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
+ buf[ofs] = ' ';
+ ofs++;
+ }
+
+ return 0;
+}
+
+bool
+couldbe_mf_symlink(const struct cifs_fattr *fattr)
+{
+ if (!S_ISREG(fattr->cf_mode))
+ /* it's not a symlink */
+ return false;
+
+ if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
+ /* it's not a symlink */
+ return false;
+
+ return true;
+}
+
+static int
+create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb, const char *fromName,
+ const char *toName)
+{
+ int rc;
+ u8 *buf;
+ unsigned int bytes_written = 0;
+
+ buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
+ if (rc)
+ goto out;
+
+ rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, cifs_sb,
+ fromName, buf, &bytes_written);
+ if (rc)
+ goto out;
+
+ if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
+ rc = -EIO;
+out:
+ kfree(buf);
+ return rc;
+}
+
+static int
+query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb, const unsigned char *path,
+ char **symlinkinfo)
+{
+ int rc;
+ u8 *buf = NULL;
+ unsigned int link_len = 0;
+ unsigned int bytes_read = 0;
+
+ buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ if (tcon->ses->server->ops->query_mf_symlink)
+ rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
+ cifs_sb, path, buf, &bytes_read);
+ else
+ rc = -ENOSYS;
+
+ if (rc)
+ goto out;
+
+ if (bytes_read == 0) { /* not a symlink */
+ rc = -EINVAL;
+ goto out;
+ }
+
+ rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
+out:
+ kfree(buf);
+ return rc;
+}
+
+int
+check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
+ const unsigned char *path)
+{
+ int rc;
+ u8 *buf = NULL;
+ unsigned int link_len = 0;
+ unsigned int bytes_read = 0;
+
+ if (!couldbe_mf_symlink(fattr))
+ /* it's not a symlink */
+ return 0;
+
+ buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ if (tcon->ses->server->ops->query_mf_symlink)
+ rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
+ cifs_sb, path, buf, &bytes_read);
+ else
+ rc = -ENOSYS;
+
+ if (rc)
+ goto out;
+
+ if (bytes_read == 0) /* not a symlink */
+ goto out;
+
+ rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
+ if (rc == -EINVAL) {
+ /* it's not a symlink */
+ rc = 0;
+ goto out;
+ }
+
+ if (rc != 0)
+ goto out;
+
+ /* it is a symlink */
+ fattr->cf_eof = link_len;
+ fattr->cf_mode &= ~S_IFMT;
+ fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
+ fattr->cf_dtype = DT_LNK;
+out:
+ kfree(buf);
+ return rc;
+}
+
+/*
+ * SMB 1.0 Protocol specific functions
+ */
+
+int
+cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb, const unsigned char *path,
+ char *pbuf, unsigned int *pbytes_read)
+{
+ int rc;
+ int oplock = 0;
+ struct cifs_fid fid;
+ struct cifs_open_parms oparms;
+ struct cifs_io_parms io_parms;
+ int buf_type = CIFS_NO_BUFFER;
+ FILE_ALL_INFO file_info;
+
+ oparms.tcon = tcon;
+ oparms.cifs_sb = cifs_sb;
+ oparms.desired_access = GENERIC_READ;
+ oparms.create_options = CREATE_NOT_DIR;
+ oparms.disposition = FILE_OPEN;
+ oparms.path = path;
+ oparms.fid = &fid;
+ oparms.reconnect = false;
+
+ rc = CIFS_open(xid, &oparms, &oplock, &file_info);
+ if (rc)
+ return rc;
+
+ if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE))
+ /* it's not a symlink */
+ goto out;
+
+ io_parms.netfid = fid.netfid;
+ io_parms.pid = current->tgid;
+ io_parms.tcon = tcon;
+ io_parms.offset = 0;
+ io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+
+ rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
+out:
+ CIFSSMBClose(xid, tcon, fid.netfid);
+ return rc;
+}
+
+int
+cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+ struct cifs_sb_info *cifs_sb, const unsigned char *path,
+ char *pbuf, unsigned int *pbytes_written)
+{
+ int rc;
+ int oplock = 0;
+ struct cifs_fid fid;
+ struct cifs_open_parms oparms;
+ struct cifs_io_parms io_parms;
+ int create_options = CREATE_NOT_DIR;
+
+ if (backup_cred(cifs_sb))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+
+ oparms.tcon = tcon;
+ oparms.cifs_sb = cifs_sb;
+ oparms.desired_access = GENERIC_WRITE;
+ oparms.create_options = create_options;
+ oparms.disposition = FILE_CREATE;
+ oparms.path = path;
+ oparms.fid = &fid;
+ oparms.reconnect = false;
+
+ rc = CIFS_open(xid, &oparms, &oplock, NULL);
+ if (rc)
+ return rc;
+
+ io_parms.netfid = fid.netfid;
+ io_parms.pid = current->tgid;
+ io_parms.tcon = tcon;
+ io_parms.offset = 0;
+ io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+
+ rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
+ CIFSSMBClose(xid, tcon, fid.netfid);
+ return rc;
+}
+
+/*
+ * M-F Symlink Functions - End
+ */
+
int
cifs_hardlink(struct dentry *old_file, struct inode *inode,
struct dentry *direntry)
{
int rc = -EACCES;
- int xid;
- char *fromName = NULL;
- char *toName = NULL;
- struct cifs_sb_info *cifs_sb_target;
- struct cifsTconInfo *pTcon;
+ unsigned int xid;
+ char *from_name = NULL;
+ char *to_name = NULL;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct tcon_link *tlink;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
struct cifsInodeInfo *cifsInode;
- xid = GetXid();
-
- cifs_sb_target = CIFS_SB(inode->i_sb);
- pTcon = cifs_sb_target->tcon;
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink))
+ return PTR_ERR(tlink);
+ tcon = tlink_tcon(tlink);
-/* No need to check for cross device links since server will do that
- BB note DFS case in future though (when we may have to check) */
+ xid = get_xid();
- fromName = build_path_from_dentry(old_file);
- toName = build_path_from_dentry(direntry);
- if ((fromName == NULL) || (toName == NULL)) {
+ from_name = build_path_from_dentry(old_file);
+ to_name = build_path_from_dentry(direntry);
+ if ((from_name == NULL) || (to_name == NULL)) {
rc = -ENOMEM;
goto cifs_hl_exit;
}
-/* if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/
- if (pTcon->unix_ext)
- rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
- cifs_sb_target->local_nls,
- cifs_sb_target->mnt_cifs_flags &
+ if (tcon->unix_ext)
+ rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
+ cifs_sb->local_nls,
+ cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
else {
- rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
- cifs_sb_target->local_nls,
- cifs_sb_target->mnt_cifs_flags &
- CIFS_MOUNT_MAP_SPECIAL_CHR);
+ server = tcon->ses->server;
+ if (!server->ops->create_hardlink) {
+ rc = -ENOSYS;
+ goto cifs_hl_exit;
+ }
+ rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
+ cifs_sb);
if ((rc == -EIO) || (rc == -EINVAL))
rc = -EOPNOTSUPP;
}
d_drop(direntry); /* force new lookup from server of target */
- /* if source file is cached (oplocked) revalidate will not go to server
- until the file is closed or oplock broken so update nlinks locally */
+ /*
+ * if source file is cached (oplocked) revalidate will not go to server
+ * until the file is closed or oplock broken so update nlinks locally
+ */
if (old_file->d_inode) {
cifsInode = CIFS_I(old_file->d_inode);
if (rc == 0) {
- old_file->d_inode->i_nlink++;
-/* BB should we make this contingent on superblock flag NOATIME? */
-/* old_file->d_inode->i_ctime = CURRENT_TIME;*/
- /* parent dir timestamps will update from srv
- within a second, would it really be worth it
- to set the parent dir cifs inode time to zero
- to force revalidate (faster) for it too? */
+ spin_lock(&old_file->d_inode->i_lock);
+ inc_nlink(old_file->d_inode);
+ spin_unlock(&old_file->d_inode->i_lock);
+ /*
+ * BB should we make this contingent on superblock flag
+ * NOATIME?
+ */
+ /* old_file->d_inode->i_ctime = CURRENT_TIME; */
+ /*
+ * parent dir timestamps will update from srv within a
+ * second, would it really be worth it to set the parent
+ * dir cifs inode time to zero to force revalidate
+ * (faster) for it too?
+ */
}
- /* if not oplocked will force revalidate to get info
- on source file from srv */
+ /*
+ * if not oplocked will force revalidate to get info on source
+ * file from srv
+ */
cifsInode->time = 0;
- /* Will update parent dir timestamps from srv within a second.
- Would it really be worth it to set the parent dir (cifs
- inode) time field to zero to force revalidate on parent
- directory faster ie
- CIFS_I(inode)->time = 0; */
+ /*
+ * Will update parent dir timestamps from srv within a second.
+ * Would it really be worth it to set the parent dir (cifs
+ * inode) time field to zero to force revalidate on parent
+ * directory faster ie
+ *
+ * CIFS_I(inode)->time = 0;
+ */
}
cifs_hl_exit:
- kfree(fromName);
- kfree(toName);
- FreeXid(xid);
+ kfree(from_name);
+ kfree(to_name);
+ free_xid(xid);
+ cifs_put_tlink(tlink);
return rc;
}
@@ -108,40 +496,44 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
{
struct inode *inode = direntry->d_inode;
int rc = -ENOMEM;
- int xid;
+ unsigned int xid;
char *full_path = NULL;
char *target_path = NULL;
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
- struct cifsTconInfo *tcon = cifs_sb->tcon;
+ struct tcon_link *tlink = NULL;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
- xid = GetXid();
+ xid = get_xid();
- /*
- * For now, we just handle symlinks with unix extensions enabled.
- * Eventually we should handle NTFS reparse points, and MacOS
- * symlink support. For instance...
- *
- * rc = CIFSSMBQueryReparseLinkInfo(...)
- *
- * For now, just return -EACCES when the server doesn't support posix
- * extensions. Note that we still allow querying symlinks when posix
- * extensions are manually disabled. We could disable these as well
- * but there doesn't seem to be any harm in allowing the client to
- * read them.
- */
- if (!(tcon->ses->capabilities & CAP_UNIX)) {
- rc = -EACCES;
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink)) {
+ rc = PTR_ERR(tlink);
+ tlink = NULL;
goto out;
}
+ tcon = tlink_tcon(tlink);
+ server = tcon->ses->server;
full_path = build_path_from_dentry(direntry);
if (!full_path)
goto out;
- cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
+ cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
+
+ rc = -EACCES;
+ /*
+ * First try Minshall+French Symlinks, if configured
+ * and fallback to UNIX Extensions Symlinks.
+ */
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
+ rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
+ &target_path);
+
+ if (rc != 0 && server->ops->query_symlink)
+ rc = server->ops->query_symlink(xid, tcon, full_path,
+ &target_path, cifs_sb);
- rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
- cifs_sb->local_nls);
kfree(full_path);
out:
if (rc != 0) {
@@ -149,7 +541,9 @@ out:
target_path = ERR_PTR(rc);
}
- FreeXid(xid);
+ free_xid(xid);
+ if (tlink)
+ cifs_put_tlink(tlink);
nd_set_link(nd, target_path);
return NULL;
}
@@ -158,30 +552,35 @@ int
cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
{
int rc = -EOPNOTSUPP;
- int xid;
- struct cifs_sb_info *cifs_sb;
- struct cifsTconInfo *pTcon;
+ unsigned int xid;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct tcon_link *tlink;
+ struct cifs_tcon *pTcon;
char *full_path = NULL;
struct inode *newinode = NULL;
- xid = GetXid();
+ xid = get_xid();
- cifs_sb = CIFS_SB(inode->i_sb);
- pTcon = cifs_sb->tcon;
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink)) {
+ rc = PTR_ERR(tlink);
+ goto symlink_exit;
+ }
+ pTcon = tlink_tcon(tlink);
full_path = build_path_from_dentry(direntry);
-
if (full_path == NULL) {
rc = -ENOMEM;
- FreeXid(xid);
- return rc;
+ goto symlink_exit;
}
- cFYI(1, ("Full path: %s", full_path));
- cFYI(1, ("symname is %s", symname));
+ cifs_dbg(FYI, "Full path: %s\n", full_path);
+ cifs_dbg(FYI, "symname is %s\n", symname);
/* BB what if DFS and this volume is on different share? BB */
- if (pTcon->unix_ext)
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
+ rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
+ else if (pTcon->unix_ext)
rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
cifs_sb->local_nls);
/* else
@@ -197,25 +596,15 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
inode->i_sb, xid, NULL);
if (rc != 0) {
- cFYI(1, ("Create symlink ok, getinodeinfo fail rc = %d",
- rc));
+ cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
+ rc);
} else {
- if (pTcon->nocase)
- direntry->d_op = &cifs_ci_dentry_ops;
- else
- direntry->d_op = &cifs_dentry_ops;
d_instantiate(direntry, newinode);
}
}
-
+symlink_exit:
kfree(full_path);
- FreeXid(xid);
+ cifs_put_tlink(tlink);
+ free_xid(xid);
return rc;
}
-
-void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
-{
- char *p = nd_get_link(nd);
- if (!IS_ERR(p))
- kfree(p);
-}