freebsd-dev/usr.sbin/rpc.lockd/kern.c
2011-12-30 10:58:14 +00:00

606 lines
15 KiB
C

/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from BSDI kern.c,v 1.2 1998/11/25 22:38:27 don Exp
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <netdb.h>
#include "nlm_prot.h"
#include <nfs/nfsproto.h>
#include <nfs/nfs_lock.h>
#include "lockd.h"
#include "lockd_lock.h"
#include <nfsclient/nfs.h>
#define DAEMON_USERNAME "daemon"
/* Lock request owner. */
typedef struct __owner {
pid_t pid; /* Process ID. */
time_t tod; /* Time-of-day. */
} OWNER;
static OWNER owner;
static char hostname[MAXHOSTNAMELEN + 1]; /* Hostname. */
static int devfd;
static void client_cleanup(void);
static const char *from_addr(struct sockaddr *);
int lock_request(LOCKD_MSG *);
static void set_auth(CLIENT *cl, struct xucred *ucred);
void show(LOCKD_MSG *);
int test_request(LOCKD_MSG *);
int unlock_request(LOCKD_MSG *);
static int
nfslockdans(int vers, struct lockd_ans *ansp)
{
ansp->la_vers = vers;
return (write(devfd, ansp, sizeof *ansp) <= 0);
}
/*
* will break because fifo needs to be repopened when EOF'd
*/
#define lockd_seteuid(uid) seteuid(uid)
#define d_calls (debug_level > 1)
#define d_args (debug_level > 2)
static const char *
from_addr(saddr)
struct sockaddr *saddr;
{
static char inet_buf[INET6_ADDRSTRLEN];
if (getnameinfo(saddr, saddr->sa_len, inet_buf, sizeof(inet_buf),
NULL, 0, NI_NUMERICHOST) == 0)
return inet_buf;
return "???";
}
void
client_cleanup(void)
{
(void)lockd_seteuid(0);
exit(-1);
}
/*
* client_request --
* Loop around messages from the kernel, forwarding them off to
* NLM servers.
*/
pid_t
client_request(void)
{
LOCKD_MSG msg;
int nr, ret;
pid_t child;
uid_t daemon_uid;
struct passwd *pw;
/* Open the dev . */
devfd = open(_PATH_DEV _PATH_NFSLCKDEV, O_RDWR | O_NONBLOCK);
if (devfd < 0) {
syslog(LOG_ERR, "open: %s: %m", _PATH_NFSLCKDEV);
goto err;
}
signal(SIGPIPE, SIG_IGN);
/*
* Create a separate process, the client code is really a separate
* daemon that shares a lot of code.
*/
switch (child = fork()) {
case -1:
err(1, "fork");
case 0:
setproctitle("client");
break;
default:
setproctitle("server");
return (child);
}
signal(SIGHUP, (sig_t)client_cleanup);
signal(SIGTERM, (sig_t)client_cleanup);
/* Setup. */
(void)time(&owner.tod);
owner.pid = getpid();
(void)gethostname(hostname, sizeof(hostname) - 1);
pw = getpwnam(DAEMON_USERNAME);
if (pw == NULL) {
syslog(LOG_ERR, "getpwnam: %s: %m", DAEMON_USERNAME);
goto err;
}
daemon_uid = pw->pw_uid;
/* drop our root privileges */
(void)lockd_seteuid(daemon_uid);
for (;;) {
/* Read the fixed length message. */
if ((nr = read(devfd, &msg, sizeof(msg))) == sizeof(msg)) {
if (d_args)
show(&msg);
if (msg.lm_version != LOCKD_MSG_VERSION) {
syslog(LOG_ERR,
"unknown msg type: %d", msg.lm_version);
}
/*
* Send it to the NLM server and don't grant the lock
* if we fail for any reason.
*/
switch (msg.lm_fl.l_type) {
case F_RDLCK:
case F_WRLCK:
if (msg.lm_getlk)
ret = test_request(&msg);
else
ret = lock_request(&msg);
break;
case F_UNLCK:
ret = unlock_request(&msg);
break;
default:
ret = 1;
syslog(LOG_ERR,
"unknown lock type: %d", msg.lm_fl.l_type);
break;
}
if (ret) {
struct lockd_ans ans;
ans.la_msg_ident = msg.lm_msg_ident;
ans.la_errno = EHOSTUNREACH;
if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
syslog((errno == EPIPE ? LOG_INFO :
LOG_ERR), "process %lu: %m",
(u_long)msg.lm_msg_ident.pid);
}
}
} else if (nr == -1) {
if (errno != EAGAIN) {
syslog(LOG_ERR, "read: %s: %m", _PATH_NFSLCKDEV);
goto err;
}
} else if (nr != 0) {
syslog(LOG_ERR,
"%s: discard %d bytes", _PATH_NFSLCKDEV, nr);
}
}
/* Reached only on error. */
err:
(void)lockd_seteuid(0);
_exit (1);
}
void
set_auth(cl, xucred)
CLIENT *cl;
struct xucred *xucred;
{
int ngroups;
ngroups = xucred->cr_ngroups - 1;
if (ngroups > NGRPS)
ngroups = NGRPS;
if (cl->cl_auth != NULL)
cl->cl_auth->ah_ops->ah_destroy(cl->cl_auth);
cl->cl_auth = authunix_create(hostname,
xucred->cr_uid,
xucred->cr_groups[0],
ngroups,
&xucred->cr_groups[1]);
}
/*
* test_request --
* Convert a lock LOCKD_MSG into an NLM request, and send it off.
*/
int
test_request(LOCKD_MSG *msg)
{
CLIENT *cli;
struct timeval timeout = {0, 0}; /* No timeout, no response. */
char dummy;
if (d_calls)
syslog(LOG_DEBUG, "test request: %s: %s to %s",
msg->lm_nfsv3 ? "V4" : "V1/3",
msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
from_addr((struct sockaddr *)&msg->lm_addr));
if (msg->lm_nfsv3) {
struct nlm4_testargs arg4;
arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
arg4.alock.caller_name = hostname;
arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
arg4.alock.fh.n_len = msg->lm_fh_len;
arg4.alock.oh.n_bytes = (char *)&owner;
arg4.alock.oh.n_len = sizeof(owner);
arg4.alock.svid = msg->lm_msg_ident.pid;
arg4.alock.l_offset = msg->lm_fl.l_start;
arg4.alock.l_len = msg->lm_fl.l_len;
if ((cli = get_client(
(struct sockaddr *)&msg->lm_addr,
NLM_VERS4)) == NULL)
return (1);
set_auth(cli, &msg->lm_cred);
(void)clnt_call(cli, NLM_TEST_MSG,
(xdrproc_t)xdr_nlm4_testargs, &arg4,
(xdrproc_t)xdr_void, &dummy, timeout);
} else {
struct nlm_testargs arg;
arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
arg.cookie.n_len = sizeof(msg->lm_msg_ident);
arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
arg.alock.caller_name = hostname;
arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
arg.alock.fh.n_len = msg->lm_fh_len;
arg.alock.oh.n_bytes = (char *)&owner;
arg.alock.oh.n_len = sizeof(owner);
arg.alock.svid = msg->lm_msg_ident.pid;
arg.alock.l_offset = msg->lm_fl.l_start;
arg.alock.l_len = msg->lm_fl.l_len;
if ((cli = get_client(
(struct sockaddr *)&msg->lm_addr,
NLM_VERS)) == NULL)
return (1);
set_auth(cli, &msg->lm_cred);
(void)clnt_call(cli, NLM_TEST_MSG,
(xdrproc_t)xdr_nlm_testargs, &arg,
(xdrproc_t)xdr_void, &dummy, timeout);
}
return (0);
}
/*
* lock_request --
* Convert a lock LOCKD_MSG into an NLM request, and send it off.
*/
int
lock_request(LOCKD_MSG *msg)
{
CLIENT *cli;
struct nlm4_lockargs arg4;
struct nlm_lockargs arg;
struct timeval timeout = {0, 0}; /* No timeout, no response. */
char dummy;
if (d_calls)
syslog(LOG_DEBUG, "lock request: %s: %s to %s",
msg->lm_nfsv3 ? "V4" : "V1/3",
msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
from_addr((struct sockaddr *)&msg->lm_addr));
if (msg->lm_nfsv3) {
arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
arg4.block = msg->lm_wait ? 1 : 0;
arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
arg4.alock.caller_name = hostname;
arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
arg4.alock.fh.n_len = msg->lm_fh_len;
arg4.alock.oh.n_bytes = (char *)&owner;
arg4.alock.oh.n_len = sizeof(owner);
arg4.alock.svid = msg->lm_msg_ident.pid;
arg4.alock.l_offset = msg->lm_fl.l_start;
arg4.alock.l_len = msg->lm_fl.l_len;
arg4.reclaim = 0;
arg4.state = nsm_state;
if ((cli = get_client(
(struct sockaddr *)&msg->lm_addr,
NLM_VERS4)) == NULL)
return (1);
set_auth(cli, &msg->lm_cred);
(void)clnt_call(cli, NLM_LOCK_MSG,
(xdrproc_t)xdr_nlm4_lockargs, &arg4,
(xdrproc_t)xdr_void, &dummy, timeout);
} else {
arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
arg.cookie.n_len = sizeof(msg->lm_msg_ident);
arg.block = msg->lm_wait ? 1 : 0;
arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
arg.alock.caller_name = hostname;
arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
arg.alock.fh.n_len = msg->lm_fh_len;
arg.alock.oh.n_bytes = (char *)&owner;
arg.alock.oh.n_len = sizeof(owner);
arg.alock.svid = msg->lm_msg_ident.pid;
arg.alock.l_offset = msg->lm_fl.l_start;
arg.alock.l_len = msg->lm_fl.l_len;
arg.reclaim = 0;
arg.state = nsm_state;
if ((cli = get_client(
(struct sockaddr *)&msg->lm_addr,
NLM_VERS)) == NULL)
return (1);
set_auth(cli, &msg->lm_cred);
(void)clnt_call(cli, NLM_LOCK_MSG,
(xdrproc_t)xdr_nlm_lockargs, &arg,
(xdrproc_t)xdr_void, &dummy, timeout);
}
return (0);
}
/*
* unlock_request --
* Convert an unlock LOCKD_MSG into an NLM request, and send it off.
*/
int
unlock_request(LOCKD_MSG *msg)
{
CLIENT *cli;
struct nlm4_unlockargs arg4;
struct nlm_unlockargs arg;
struct timeval timeout = {0, 0}; /* No timeout, no response. */
char dummy;
if (d_calls)
syslog(LOG_DEBUG, "unlock request: %s: to %s",
msg->lm_nfsv3 ? "V4" : "V1/3",
from_addr((struct sockaddr *)&msg->lm_addr));
if (msg->lm_nfsv3) {
arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
arg4.alock.caller_name = hostname;
arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
arg4.alock.fh.n_len = msg->lm_fh_len;
arg4.alock.oh.n_bytes = (char *)&owner;
arg4.alock.oh.n_len = sizeof(owner);
arg4.alock.svid = msg->lm_msg_ident.pid;
arg4.alock.l_offset = msg->lm_fl.l_start;
arg4.alock.l_len = msg->lm_fl.l_len;
if ((cli = get_client(
(struct sockaddr *)&msg->lm_addr,
NLM_VERS4)) == NULL)
return (1);
set_auth(cli, &msg->lm_cred);
(void)clnt_call(cli, NLM_UNLOCK_MSG,
(xdrproc_t)xdr_nlm4_unlockargs, &arg4,
(xdrproc_t)xdr_void, &dummy, timeout);
} else {
arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
arg.cookie.n_len = sizeof(msg->lm_msg_ident);
arg.alock.caller_name = hostname;
arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
arg.alock.fh.n_len = msg->lm_fh_len;
arg.alock.oh.n_bytes = (char *)&owner;
arg.alock.oh.n_len = sizeof(owner);
arg.alock.svid = msg->lm_msg_ident.pid;
arg.alock.l_offset = msg->lm_fl.l_start;
arg.alock.l_len = msg->lm_fl.l_len;
if ((cli = get_client(
(struct sockaddr *)&msg->lm_addr,
NLM_VERS)) == NULL)
return (1);
set_auth(cli, &msg->lm_cred);
(void)clnt_call(cli, NLM_UNLOCK_MSG,
(xdrproc_t)xdr_nlm_unlockargs, &arg,
(xdrproc_t)xdr_void, &dummy, timeout);
}
return (0);
}
int
lock_answer(int pid, netobj *netcookie, int result, int *pid_p, int version)
{
struct lockd_ans ans;
if (netcookie->n_len != sizeof(ans.la_msg_ident)) {
if (pid == -1) { /* we're screwed */
syslog(LOG_ERR, "inedible nlm cookie");
return -1;
}
ans.la_msg_ident.pid = pid;
ans.la_msg_ident.msg_seq = -1;
} else {
memcpy(&ans.la_msg_ident, netcookie->n_bytes,
sizeof(ans.la_msg_ident));
}
if (d_calls)
syslog(LOG_DEBUG, "lock answer: pid %lu: %s %d",
(unsigned long)ans.la_msg_ident.pid,
version == NLM_VERS4 ? "nlmv4" : "nlmv3",
result);
ans.la_set_getlk_pid = 0;
if (version == NLM_VERS4)
switch (result) {
case nlm4_granted:
ans.la_errno = 0;
break;
default:
ans.la_errno = EACCES;
break;
case nlm4_denied:
if (pid_p == NULL)
ans.la_errno = EAGAIN;
else {
/* this is an answer to a nlm_test msg */
ans.la_set_getlk_pid = 1;
ans.la_getlk_pid = *pid_p;
ans.la_errno = 0;
}
break;
case nlm4_denied_nolocks:
ans.la_errno = EAGAIN;
break;
case nlm4_blocked:
return -1;
/* NOTREACHED */
case nlm4_denied_grace_period:
ans.la_errno = EAGAIN;
break;
case nlm4_deadlck:
ans.la_errno = EDEADLK;
break;
case nlm4_rofs:
ans.la_errno = EROFS;
break;
case nlm4_stale_fh:
ans.la_errno = ESTALE;
break;
case nlm4_fbig:
ans.la_errno = EFBIG;
break;
case nlm4_failed:
ans.la_errno = EACCES;
break;
}
else
switch (result) {
case nlm_granted:
ans.la_errno = 0;
break;
default:
ans.la_errno = EACCES;
break;
case nlm_denied:
if (pid_p == NULL)
ans.la_errno = EAGAIN;
else {
/* this is an answer to a nlm_test msg */
ans.la_set_getlk_pid = 1;
ans.la_getlk_pid = *pid_p;
ans.la_errno = 0;
}
break;
case nlm_denied_nolocks:
ans.la_errno = EAGAIN;
break;
case nlm_blocked:
return -1;
/* NOTREACHED */
case nlm_denied_grace_period:
ans.la_errno = EAGAIN;
break;
case nlm_deadlck:
ans.la_errno = EDEADLK;
break;
}
if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
syslog(((errno == EPIPE || errno == ESRCH) ?
LOG_INFO : LOG_ERR),
"process %lu: %m", (u_long)ans.la_msg_ident.pid);
return -1;
}
return 0;
}
/*
* show --
* Display the contents of a kernel LOCKD_MSG structure.
*/
void
show(LOCKD_MSG *mp)
{
static char hex[] = "0123456789abcdef";
struct fid *fidp;
fsid_t *fsidp;
size_t len;
u_int8_t *p, *t, buf[NFS_SMALLFH*3+1];
syslog(LOG_DEBUG, "process ID: %lu\n", (long)mp->lm_msg_ident.pid);
fsidp = (fsid_t *)&mp->lm_fh;
fidp = (struct fid *)((u_int8_t *)&mp->lm_fh + sizeof(fsid_t));
for (t = buf, p = (u_int8_t *)mp->lm_fh,
len = mp->lm_fh_len;
len > 0; ++p, --len) {
*t++ = '\\';
*t++ = hex[(*p & 0xf0) >> 4];
*t++ = hex[*p & 0x0f];
}
*t = '\0';
syslog(LOG_DEBUG, "fh_len %d, fh %s\n", (int)mp->lm_fh_len, buf);
/* Show flock structure. */
syslog(LOG_DEBUG, "start %qu; len %qu; pid %lu; type %d; whence %d\n",
(unsigned long long)mp->lm_fl.l_start,
(unsigned long long)mp->lm_fl.l_len, (u_long)mp->lm_fl.l_pid,
mp->lm_fl.l_type, mp->lm_fl.l_whence);
/* Show wait flag. */
syslog(LOG_DEBUG, "wait was %s\n", mp->lm_wait ? "set" : "not set");
}