linux/fs/nfs/nfs4namespace.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

520 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/nfs/nfs4namespace.c
*
* Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
* - Modified by David Howells <dhowells@redhat.com>
*
* NFSv4 namespace
*/
#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/addr.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include "internal.h"
#include "nfs4_fs.h"
#include "dns_resolve.h"
#define NFSDBG_FACILITY NFSDBG_VFS
/*
* Convert the NFSv4 pathname components into a standard posix path.
*
* Note that the resulting string will be placed at the end of the buffer
*/
static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
char *buffer, ssize_t buflen)
{
char *end = buffer + buflen;
int n;
*--end = '\0';
buflen--;
n = pathname->ncomponents;
while (--n >= 0) {
const struct nfs4_string *component = &pathname->components[n];
buflen -= component->len + 1;
if (buflen < 0)
goto Elong;
end -= component->len;
memcpy(end, component->data, component->len);
*--end = '/';
}
return end;
Elong:
return ERR_PTR(-ENAMETOOLONG);
}
/*
* return the path component of "<server>:<path>"
* nfspath - the "<server>:<path>" string
* end - one past the last char that could contain "<server>:"
* returns NULL on failure
*/
static char *nfs_path_component(const char *nfspath, const char *end)
{
char *p;
if (*nfspath == '[') {
/* parse [] escaped IPv6 addrs */
p = strchr(nfspath, ']');
if (p != NULL && ++p < end && *p == ':')
return p + 1;
} else {
/* otherwise split on first colon */
p = strchr(nfspath, ':');
if (p != NULL && p < end)
return p + 1;
}
return NULL;
}
/*
* Determine the mount path as a string
*/
static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
{
char *limit;
char *path = nfs_path(&limit, dentry, buffer, buflen,
NFS_PATH_CANONICAL);
if (!IS_ERR(path)) {
char *path_component = nfs_path_component(path, limit);
if (path_component)
return path_component;
}
return path;
}
/*
* Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
* believe to be the server path to this dentry
*/
static int nfs4_validate_fspath(struct dentry *dentry,
const struct nfs4_fs_locations *locations,
char *page, char *page2)
{
const char *path, *fs_path;
path = nfs4_path(dentry, page, PAGE_SIZE);
if (IS_ERR(path))
return PTR_ERR(path);
fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
if (IS_ERR(fs_path))
return PTR_ERR(fs_path);
if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
dprintk("%s: path %s does not begin with fsroot %s\n",
__func__, path, fs_path);
return -ENOENT;
}
return 0;
}
static size_t nfs_parse_server_name(char *string, size_t len,
struct sockaddr *sa, size_t salen, struct net *net)
{
ssize_t ret;
ret = rpc_pton(net, string, len, sa, salen);
if (ret == 0) {
ret = nfs_dns_resolve_name(net, string, len, sa, salen);
if (ret < 0)
ret = 0;
}
return ret;
}
/**
* nfs_find_best_sec - Find a security mechanism supported locally
* @server: NFS server struct
* @flavors: List of security tuples returned by SECINFO procedure
*
* Return an rpc client that uses the first security mechanism in
* "flavors" that is locally supported. The "flavors" array
* is searched in the order returned from the server, per RFC 3530
* recommendation and each flavor is checked for membership in the
* sec= mount option list if it exists.
*
* Return -EPERM if no matching flavor is found in the array.
*
* Please call rpc_shutdown_client() when you are done with this rpc client.
*
*/
static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt,
struct nfs_server *server,
struct nfs4_secinfo_flavors *flavors)
{
rpc_authflavor_t pflavor;
struct nfs4_secinfo4 *secinfo;
unsigned int i;
for (i = 0; i < flavors->num_flavors; i++) {
secinfo = &flavors->flavors[i];
switch (secinfo->flavor) {
case RPC_AUTH_NULL:
case RPC_AUTH_UNIX:
case RPC_AUTH_GSS:
pflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
&secinfo->flavor_info);
/* does the pseudoflavor match a sec= mount opt? */
if (pflavor != RPC_AUTH_MAXFLAVOR &&
nfs_auth_info_match(&server->auth_info, pflavor)) {
struct rpc_clnt *new;
struct rpc_cred *cred;
/* Cloning creates an rpc_auth for the flavor */
new = rpc_clone_client_set_auth(clnt, pflavor);
if (IS_ERR(new))
continue;
/**
* Check that the user actually can use the
* flavor. This is mostly for RPC_AUTH_GSS
* where cr_init obtains a gss context
*/
cred = rpcauth_lookupcred(new->cl_auth, 0);
if (IS_ERR(cred)) {
rpc_shutdown_client(new);
continue;
}
put_rpccred(cred);
return new;
}
}
}
return ERR_PTR(-EPERM);
}
/**
* nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup,
* return an rpc_clnt that uses the best available security flavor with
* respect to the secinfo flavor list and the sec= mount options.
*
* @clnt: RPC client to clone
* @inode: directory inode
* @name: lookup name
*
* Please call rpc_shutdown_client() when you are done with this rpc client.
*/
struct rpc_clnt *
nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode,
const struct qstr *name)
{
struct page *page;
struct nfs4_secinfo_flavors *flavors;
struct rpc_clnt *new;
int err;
page = alloc_page(GFP_KERNEL);
if (!page)
return ERR_PTR(-ENOMEM);
flavors = page_address(page);
err = nfs4_proc_secinfo(inode, name, flavors);
if (err < 0) {
new = ERR_PTR(err);
goto out;
}
new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
out:
put_page(page);
return new;
}
static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
char *page, char *page2,
const struct nfs4_fs_location *location)
{
const size_t addr_bufsize = sizeof(struct sockaddr_storage);
struct net *net = rpc_net_ns(NFS_SB(mountdata->sb)->client);
struct vfsmount *mnt = ERR_PTR(-ENOENT);
char *mnt_path;
unsigned int maxbuflen;
unsigned int s;
mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
if (IS_ERR(mnt_path))
return ERR_CAST(mnt_path);
mountdata->mnt_path = mnt_path;
maxbuflen = mnt_path - 1 - page2;
mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
if (mountdata->addr == NULL)
return ERR_PTR(-ENOMEM);
for (s = 0; s < location->nservers; s++) {
const struct nfs4_string *buf = &location->servers[s];
if (buf->len <= 0 || buf->len >= maxbuflen)
continue;
if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
continue;
mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
mountdata->addr, addr_bufsize, net);
if (mountdata->addrlen == 0)
continue;
rpc_set_port(mountdata->addr, NFS_PORT);
memcpy(page2, buf->data, buf->len);
page2[buf->len] = '\0';
mountdata->hostname = page2;
snprintf(page, PAGE_SIZE, "%s:%s",
mountdata->hostname,
mountdata->mnt_path);
mnt = vfs_submount(mountdata->dentry, &nfs4_referral_fs_type, page, mountdata);
if (!IS_ERR(mnt))
break;
}
kfree(mountdata->addr);
return mnt;
}
/**
* nfs_follow_referral - set up mountpoint when hitting a referral on moved error
* @dentry - parent directory
* @locations - array of NFSv4 server location information
*
*/
static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
const struct nfs4_fs_locations *locations)
{
struct vfsmount *mnt = ERR_PTR(-ENOENT);
struct nfs_clone_mount mountdata = {
.sb = dentry->d_sb,
.dentry = dentry,
.authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
};
char *page = NULL, *page2 = NULL;
int loc, error;
if (locations == NULL || locations->nlocations <= 0)
goto out;
dprintk("%s: referral at %pd2\n", __func__, dentry);
page = (char *) __get_free_page(GFP_USER);
if (!page)
goto out;
page2 = (char *) __get_free_page(GFP_USER);
if (!page2)
goto out;
/* Ensure fs path is a prefix of current dentry path */
error = nfs4_validate_fspath(dentry, locations, page, page2);
if (error < 0) {
mnt = ERR_PTR(error);
goto out;
}
for (loc = 0; loc < locations->nlocations; loc++) {
const struct nfs4_fs_location *location = &locations->locations[loc];
if (location == NULL || location->nservers <= 0 ||
location->rootpath.ncomponents == 0)
continue;
mnt = try_location(&mountdata, page, page2, location);
if (!IS_ERR(mnt))
break;
}
out:
free_page((unsigned long) page);
free_page((unsigned long) page2);
return mnt;
}
/*
* nfs_do_refmount - handle crossing a referral on server
* @dentry - dentry of referral
*
*/
static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
{
struct vfsmount *mnt = ERR_PTR(-ENOMEM);
struct dentry *parent;
struct nfs4_fs_locations *fs_locations = NULL;
struct page *page;
int err;
/* BUG_ON(IS_ROOT(dentry)); */
page = alloc_page(GFP_KERNEL);
if (page == NULL)
return mnt;
fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
if (fs_locations == NULL)
goto out_free;
/* Get locations */
mnt = ERR_PTR(-ENOENT);
parent = dget_parent(dentry);
dprintk("%s: getting locations for %pd2\n",
__func__, dentry);
err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page);
dput(parent);
if (err != 0 ||
fs_locations->nlocations <= 0 ||
fs_locations->fs_path.ncomponents <= 0)
goto out_free;
mnt = nfs_follow_referral(dentry, fs_locations);
out_free:
__free_page(page);
kfree(fs_locations);
return mnt;
}
struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
struct nfs_fh *fh, struct nfs_fattr *fattr)
{
rpc_authflavor_t flavor = server->client->cl_auth->au_flavor;
struct dentry *parent = dget_parent(dentry);
struct inode *dir = d_inode(parent);
const struct qstr *name = &dentry->d_name;
struct rpc_clnt *client;
struct vfsmount *mnt;
/* Look it up again to get its attributes and sec flavor */
client = nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
dput(parent);
if (IS_ERR(client))
return ERR_CAST(client);
if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
mnt = nfs_do_refmount(client, dentry);
goto out;
}
if (client->cl_auth->au_flavor != flavor)
flavor = client->cl_auth->au_flavor;
mnt = nfs_do_submount(dentry, fh, fattr, flavor);
out:
rpc_shutdown_client(client);
return mnt;
}
/*
* Try one location from the fs_locations array.
*
* Returns zero on success, or a negative errno value.
*/
static int nfs4_try_replacing_one_location(struct nfs_server *server,
char *page, char *page2,
const struct nfs4_fs_location *location)
{
const size_t addr_bufsize = sizeof(struct sockaddr_storage);
struct net *net = rpc_net_ns(server->client);
struct sockaddr *sap;
unsigned int s;
size_t salen;
int error;
sap = kmalloc(addr_bufsize, GFP_KERNEL);
if (sap == NULL)
return -ENOMEM;
error = -ENOENT;
for (s = 0; s < location->nservers; s++) {
const struct nfs4_string *buf = &location->servers[s];
char *hostname;
if (buf->len <= 0 || buf->len > PAGE_SIZE)
continue;
if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL)
continue;
salen = nfs_parse_server_name(buf->data, buf->len,
sap, addr_bufsize, net);
if (salen == 0)
continue;
rpc_set_port(sap, NFS_PORT);
error = -ENOMEM;
hostname = kstrndup(buf->data, buf->len, GFP_KERNEL);
if (hostname == NULL)
break;
error = nfs4_update_server(server, hostname, sap, salen, net);
kfree(hostname);
if (error == 0)
break;
}
kfree(sap);
return error;
}
/**
* nfs4_replace_transport - set up transport to destination server
*
* @server: export being migrated
* @locations: fs_locations array
*
* Returns zero on success, or a negative errno value.
*
* The client tries all the entries in the "locations" array, in the
* order returned by the server, until one works or the end of the
* array is reached.
*/
int nfs4_replace_transport(struct nfs_server *server,
const struct nfs4_fs_locations *locations)
{
char *page = NULL, *page2 = NULL;
int loc, error;
error = -ENOENT;
if (locations == NULL || locations->nlocations <= 0)
goto out;
error = -ENOMEM;
page = (char *) __get_free_page(GFP_USER);
if (!page)
goto out;
page2 = (char *) __get_free_page(GFP_USER);
if (!page2)
goto out;
for (loc = 0; loc < locations->nlocations; loc++) {
const struct nfs4_fs_location *location =
&locations->locations[loc];
if (location == NULL || location->nservers <= 0 ||
location->rootpath.ncomponents == 0)
continue;
error = nfs4_try_replacing_one_location(server, page,
page2, location);
if (error == 0)
break;
}
out:
free_page((unsigned long)page);
free_page((unsigned long)page2);
return error;
}