linux/fs/lockd/mon.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

577 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/lockd/mon.c
*
* The kernel statd client.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <asm/unaligned.h>
#include "netns.h"
#define NLMDBG_FACILITY NLMDBG_MONITOR
#define NSM_PROGRAM 100024
#define NSM_VERSION 1
enum {
NSMPROC_NULL,
NSMPROC_STAT,
NSMPROC_MON,
NSMPROC_UNMON,
NSMPROC_UNMON_ALL,
NSMPROC_SIMU_CRASH,
NSMPROC_NOTIFY,
};
struct nsm_args {
struct nsm_private *priv;
u32 prog; /* RPC callback info */
u32 vers;
u32 proc;
char *mon_name;
const char *nodename;
};
struct nsm_res {
u32 status;
u32 state;
};
static const struct rpc_program nsm_program;
static DEFINE_SPINLOCK(nsm_lock);
/*
* Local NSM state
*/
u32 __read_mostly nsm_local_state;
bool __read_mostly nsm_use_hostnames;
static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
{
return (struct sockaddr *)&nsm->sm_addr;
}
static struct rpc_clnt *nsm_create(struct net *net, const char *nodename)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
};
struct rpc_create_args args = {
.net = net,
.protocol = XPRT_TRANSPORT_TCP,
.address = (struct sockaddr *)&sin,
.addrsize = sizeof(sin),
.servername = "rpc.statd",
.nodename = nodename,
.program = &nsm_program,
.version = NSM_VERSION,
.authflavor = RPC_AUTH_NULL,
.flags = RPC_CLNT_CREATE_NOPING,
};
return rpc_create(&args);
}
static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
const struct nlm_host *host)
{
int status;
struct rpc_clnt *clnt;
struct nsm_args args = {
.priv = &nsm->sm_priv,
.prog = NLM_PROGRAM,
.vers = 3,
.proc = NLMPROC_NSM_NOTIFY,
.mon_name = nsm->sm_mon_name,
.nodename = host->nodename,
};
struct rpc_message msg = {
.rpc_argp = &args,
.rpc_resp = res,
};
memset(res, 0, sizeof(*res));
clnt = nsm_create(host->net, host->nodename);
if (IS_ERR(clnt)) {
dprintk("lockd: failed to create NSM upcall transport, "
"status=%ld, net=%p\n", PTR_ERR(clnt), host->net);
return PTR_ERR(clnt);
}
msg.rpc_proc = &clnt->cl_procinfo[proc];
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
if (status == -ECONNREFUSED) {
dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n",
status);
rpc_force_rebind(clnt);
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
}
if (status < 0)
dprintk("lockd: NSM upcall RPC failed, status=%d\n",
status);
else
status = 0;
rpc_shutdown_client(clnt);
return status;
}
/**
* nsm_monitor - Notify a peer in case we reboot
* @host: pointer to nlm_host of peer to notify
*
* If this peer is not already monitored, this function sends an
* upcall to the local rpc.statd to record the name/address of
* the peer to notify in case we reboot.
*
* Returns zero if the peer is monitored by the local rpc.statd;
* otherwise a negative errno value is returned.
*/
int nsm_monitor(const struct nlm_host *host)
{
struct nsm_handle *nsm = host->h_nsmhandle;
struct nsm_res res;
int status;
dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
if (nsm->sm_monitored)
return 0;
/*
* Choose whether to record the caller_name or IP address of
* this peer in the local rpc.statd's database.
*/
nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host);
if (unlikely(res.status != 0))
status = -EIO;
if (unlikely(status < 0)) {
pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name);
return status;
}
nsm->sm_monitored = 1;
if (unlikely(nsm_local_state != res.state)) {
nsm_local_state = res.state;
dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
}
return 0;
}
/**
* nsm_unmonitor - Unregister peer notification
* @host: pointer to nlm_host of peer to stop monitoring
*
* If this peer is monitored, this function sends an upcall to
* tell the local rpc.statd not to send this peer a notification
* when we reboot.
*/
void nsm_unmonitor(const struct nlm_host *host)
{
struct nsm_handle *nsm = host->h_nsmhandle;
struct nsm_res res;
int status;
if (atomic_read(&nsm->sm_count) == 1
&& nsm->sm_monitored && !nsm->sm_sticky) {
dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host);
if (res.status != 0)
status = -EIO;
if (status < 0)
printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
nsm->sm_name);
else
nsm->sm_monitored = 0;
}
}
static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles,
const char *hostname, const size_t len)
{
struct nsm_handle *nsm;
list_for_each_entry(nsm, nsm_handles, sm_link)
if (strlen(nsm->sm_name) == len &&
memcmp(nsm->sm_name, hostname, len) == 0)
return nsm;
return NULL;
}
static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles,
const struct sockaddr *sap)
{
struct nsm_handle *nsm;
list_for_each_entry(nsm, nsm_handles, sm_link)
if (rpc_cmp_addr(nsm_addr(nsm), sap))
return nsm;
return NULL;
}
static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles,
const struct nsm_private *priv)
{
struct nsm_handle *nsm;
list_for_each_entry(nsm, nsm_handles, sm_link)
if (memcmp(nsm->sm_priv.data, priv->data,
sizeof(priv->data)) == 0)
return nsm;
return NULL;
}
/*
* Construct a unique cookie to match this nsm_handle to this monitored
* host. It is passed to the local rpc.statd via NSMPROC_MON, and
* returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
* requests.
*
* The NSM protocol requires that these cookies be unique while the
* system is running. We prefer a stronger requirement of making them
* unique across reboots. If user space bugs cause a stale cookie to
* be sent to the kernel, it could cause the wrong host to lose its
* lock state if cookies were not unique across reboots.
*
* The cookies are exposed only to local user space via loopback. They
* do not appear on the physical network. If we want greater security
* for some reason, nsm_init_private() could perform a one-way hash to
* obscure the contents of the cookie.
*/
static void nsm_init_private(struct nsm_handle *nsm)
{
u64 *p = (u64 *)&nsm->sm_priv.data;
s64 ns;
ns = ktime_get_ns();
put_unaligned(ns, p);
put_unaligned((unsigned long)nsm, p + 1);
}
static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
const size_t salen,
const char *hostname,
const size_t hostname_len)
{
struct nsm_handle *new;
new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
if (unlikely(new == NULL))
return NULL;
atomic_set(&new->sm_count, 1);
new->sm_name = (char *)(new + 1);
memcpy(nsm_addr(new), sap, salen);
new->sm_addrlen = salen;
nsm_init_private(new);
if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
sizeof(new->sm_addrbuf)) == 0)
(void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
"unsupported address family");
memcpy(new->sm_name, hostname, hostname_len);
new->sm_name[hostname_len] = '\0';
return new;
}
/**
* nsm_get_handle - Find or create a cached nsm_handle
* @net: network namespace
* @sap: pointer to socket address of handle to find
* @salen: length of socket address
* @hostname: pointer to C string containing hostname to find
* @hostname_len: length of C string
*
* Behavior is modulated by the global nsm_use_hostnames variable.
*
* Returns a cached nsm_handle after bumping its ref count, or
* returns a fresh nsm_handle if a handle that matches @sap and/or
* @hostname cannot be found in the handle cache. Returns NULL if
* an error occurs.
*/
struct nsm_handle *nsm_get_handle(const struct net *net,
const struct sockaddr *sap,
const size_t salen, const char *hostname,
const size_t hostname_len)
{
struct nsm_handle *cached, *new = NULL;
struct lockd_net *ln = net_generic(net, lockd_net_id);
if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
if (printk_ratelimit()) {
printk(KERN_WARNING "Invalid hostname \"%.*s\" "
"in NFS lock request\n",
(int)hostname_len, hostname);
}
return NULL;
}
retry:
spin_lock(&nsm_lock);
if (nsm_use_hostnames && hostname != NULL)
cached = nsm_lookup_hostname(&ln->nsm_handles,
hostname, hostname_len);
else
cached = nsm_lookup_addr(&ln->nsm_handles, sap);
if (cached != NULL) {
atomic_inc(&cached->sm_count);
spin_unlock(&nsm_lock);
kfree(new);
dprintk("lockd: found nsm_handle for %s (%s), "
"cnt %d\n", cached->sm_name,
cached->sm_addrbuf,
atomic_read(&cached->sm_count));
return cached;
}
if (new != NULL) {
list_add(&new->sm_link, &ln->nsm_handles);
spin_unlock(&nsm_lock);
dprintk("lockd: created nsm_handle for %s (%s)\n",
new->sm_name, new->sm_addrbuf);
return new;
}
spin_unlock(&nsm_lock);
new = nsm_create_handle(sap, salen, hostname, hostname_len);
if (unlikely(new == NULL))
return NULL;
goto retry;
}
/**
* nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
* @net: network namespace
* @info: pointer to NLMPROC_SM_NOTIFY arguments
*
* Returns a matching nsm_handle if found in the nsm cache. The returned
* nsm_handle's reference count is bumped. Otherwise returns NULL if some
* error occurred.
*/
struct nsm_handle *nsm_reboot_lookup(const struct net *net,
const struct nlm_reboot *info)
{
struct nsm_handle *cached;
struct lockd_net *ln = net_generic(net, lockd_net_id);
spin_lock(&nsm_lock);
cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv);
if (unlikely(cached == NULL)) {
spin_unlock(&nsm_lock);
dprintk("lockd: never saw rebooted peer '%.*s' before\n",
info->len, info->mon);
return cached;
}
atomic_inc(&cached->sm_count);
spin_unlock(&nsm_lock);
dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
cached->sm_name, cached->sm_addrbuf,
atomic_read(&cached->sm_count));
return cached;
}
/**
* nsm_release - Release an NSM handle
* @nsm: pointer to handle to be released
*
*/
void nsm_release(struct nsm_handle *nsm)
{
if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
list_del(&nsm->sm_link);
spin_unlock(&nsm_lock);
dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
nsm->sm_name, nsm->sm_addrbuf);
kfree(nsm);
}
}
/*
* XDR functions for NSM.
*
* See http://www.opengroup.org/ for details on the Network
* Status Monitor wire protocol.
*/
static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
{
const u32 len = strlen(string);
__be32 *p;
p = xdr_reserve_space(xdr, 4 + len);
xdr_encode_opaque(p, string, len);
}
/*
* "mon_name" specifies the host to be monitored.
*/
static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
{
encode_nsm_string(xdr, argp->mon_name);
}
/*
* The "my_id" argument specifies the hostname and RPC procedure
* to be called when the status manager receives notification
* (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
* has changed.
*/
static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
__be32 *p;
encode_nsm_string(xdr, argp->nodename);
p = xdr_reserve_space(xdr, 4 + 4 + 4);
*p++ = cpu_to_be32(argp->prog);
*p++ = cpu_to_be32(argp->vers);
*p = cpu_to_be32(argp->proc);
}
/*
* The "mon_id" argument specifies the non-private arguments
* of an NSMPROC_MON or NSMPROC_UNMON call.
*/
static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
encode_mon_name(xdr, argp);
encode_my_id(xdr, argp);
}
/*
* The "priv" argument may contain private information required
* by the NSMPROC_MON call. This information will be supplied in the
* NLMPROC_SM_NOTIFY call.
*/
static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
{
__be32 *p;
p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
}
static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
const void *argp)
{
encode_mon_id(xdr, argp);
encode_priv(xdr, argp);
}
static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
const void *argp)
{
encode_mon_id(xdr, argp);
}
static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nsm_res *resp = data;
__be32 *p;
p = xdr_inline_decode(xdr, 4 + 4);
if (unlikely(p == NULL))
return -EIO;
resp->status = be32_to_cpup(p++);
resp->state = be32_to_cpup(p);
dprintk("lockd: %s status %d state %d\n",
__func__, resp->status, resp->state);
return 0;
}
static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nsm_res *resp = data;
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(p == NULL))
return -EIO;
resp->state = be32_to_cpup(p);
dprintk("lockd: %s state %d\n", __func__, resp->state);
return 0;
}
#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_my_id_sz (SM_my_name_sz+3)
#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
#define SM_monres_sz 2
#define SM_unmonres_sz 1
static const struct rpc_procinfo nsm_procedures[] = {
[NSMPROC_MON] = {
.p_proc = NSMPROC_MON,
.p_encode = nsm_xdr_enc_mon,
.p_decode = nsm_xdr_dec_stat_res,
.p_arglen = SM_mon_sz,
.p_replen = SM_monres_sz,
.p_statidx = NSMPROC_MON,
.p_name = "MONITOR",
},
[NSMPROC_UNMON] = {
.p_proc = NSMPROC_UNMON,
.p_encode = nsm_xdr_enc_unmon,
.p_decode = nsm_xdr_dec_stat,
.p_arglen = SM_mon_id_sz,
.p_replen = SM_unmonres_sz,
.p_statidx = NSMPROC_UNMON,
.p_name = "UNMONITOR",
},
};
static unsigned int nsm_version1_counts[ARRAY_SIZE(nsm_procedures)];
static const struct rpc_version nsm_version1 = {
.number = 1,
.nrprocs = ARRAY_SIZE(nsm_procedures),
.procs = nsm_procedures,
.counts = nsm_version1_counts,
};
static const struct rpc_version *nsm_version[] = {
[1] = &nsm_version1,
};
static struct rpc_stat nsm_stats;
static const struct rpc_program nsm_program = {
.name = "statd",
.number = NSM_PROGRAM,
.nrvers = ARRAY_SIZE(nsm_version),
.version = nsm_version,
.stats = &nsm_stats
};