blob: 3ca69862d0d5b6b5c51fbbd484e0db7e739afc42 [file] [log] [blame]
/*
* stropts.c -- NFS mount using C string to pass options to kernel
*
* Copyright (C) 2007 Oracle. All rights reserved.
* Copyright (C) 2007 Chuck Lever <chuck.lever@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 0211-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <unistd.h>
#include <errno.h>
#include <netdb.h>
#include <time.h>
#include <sys/socket.h>
#include <sys/mount.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "nfslib.h"
#include "sockaddr.h"
#include "xcommon.h"
#include "mount.h"
#include "nls.h"
#include "nfsrpc.h"
#include "mount_constants.h"
#include "stropts.h"
#include "error.h"
#include "network.h"
#include "parse_opt.h"
#include "version.h"
#include "parse_dev.h"
#include "conffile.h"
#include "misc.h"
#ifndef NFS_PROGRAM
#define NFS_PROGRAM (100003)
#endif
#ifndef NFS_PORT
#define NFS_PORT (2049)
#endif
#ifndef NFS_MAXHOSTNAME
#define NFS_MAXHOSTNAME (255)
#endif
#ifndef NFS_MAXPATHNAME
#define NFS_MAXPATHNAME (1024)
#endif
#ifndef NFS_DEF_FG_TIMEOUT_MINUTES
#define NFS_DEF_FG_TIMEOUT_MINUTES (2u)
#endif
#ifndef NFS_DEF_BG_TIMEOUT_MINUTES
#define NFS_DEF_BG_TIMEOUT_MINUTES (10000u)
#endif
#ifndef NFS_DEFAULT_MAJOR
#define NFS_DEFAULT_MAJOR 4
#endif
#ifndef NFS_DEFAULT_MINOR
#define NFS_DEFAULT_MINOR 2
#endif
extern int nfs_mount_data_version;
extern char *progname;
extern int verbose;
extern int sloppy;
struct nfsmount_info {
const char *spec, /* server:/path */
*node; /* mounted-on dir */
char *type; /* "nfs" or "nfs4" */
char *hostname; /* server's hostname */
struct addrinfo *address; /* server's addresses */
sa_family_t family; /* Address family */
struct mount_options *options; /* parsed mount options */
char **extra_opts; /* string for /etc/mtab */
struct nfs_version version; /* NFS version */
int flags, /* MS_ flags */
fake, /* actually do the mount? */
child; /* forked bg child? */
};
static void nfs_default_version(struct nfsmount_info *mi)
{
#ifdef MOUNT_CONFIG
extern struct nfs_version config_default_vers;
/*
* Use the default value set in the config file when
* the version has not been explicitly set.
*/
if (config_default_vers.v_mode == V_PARSE_ERR) {
mi->version.v_mode = V_PARSE_ERR;
return;
}
if (mi->version.v_mode == V_DEFAULT &&
config_default_vers.v_mode != V_DEFAULT) {
mi->version.major = config_default_vers.major;
if (config_default_vers.v_mode == V_SPECIFIC)
mi->version.minor = config_default_vers.minor;
else
mi->version.minor = NFS_DEFAULT_MINOR;
return;
}
if (mi->version.v_mode == V_GENERAL) {
if (config_default_vers.v_mode != V_DEFAULT &&
mi->version.major == config_default_vers.major) {
if (config_default_vers.v_mode == V_SPECIFIC)
mi->version.minor = config_default_vers.minor;
else
mi->version.minor = NFS_DEFAULT_MINOR;
} else
mi->version.minor = NFS_DEFAULT_MINOR;
return;
}
#endif /* MOUNT_CONFIG */
mi->version.major = NFS_DEFAULT_MAJOR;
mi->version.minor = NFS_DEFAULT_MINOR;
}
/*
* Obtain a retry timeout value based on the value of the "retry=" option.
*
* Returns a time_t timeout timestamp, in seconds.
*/
static time_t nfs_parse_retry_option(struct mount_options *options,
const time_t default_timeout)
{
time_t timeout_minutes;
long tmp;
timeout_minutes = default_timeout;
switch (po_get_numeric(options, "retry", &tmp)) {
case PO_NOT_FOUND:
break;
case PO_FOUND:
if (tmp >= 0) {
timeout_minutes = tmp;
break;
}
/*FALLTHROUGH*/
case PO_BAD_VALUE:
if (verbose)
nfs_error(_("%s: invalid retry timeout was specified; "
"using default timeout"), progname);
break;
}
return time(NULL) + (timeout_minutes * 60);
}
/*
* Convert the passed-in sockaddr-style address to presentation
* format, then append an option of the form "keyword=address".
*
* Returns 1 if the option was appended successfully; otherwise zero.
*/
static int nfs_append_generic_address_option(const struct sockaddr *sap,
const socklen_t salen,
const char *keyword,
struct mount_options *options)
{
char address[NI_MAXHOST];
char new_option[512];
int len;
if (!nfs_present_sockaddr(sap, salen, address, sizeof(address)))
goto out_err;
len = snprintf(new_option, sizeof(new_option), "%s=%s",
keyword, address);
if (len < 0 || (size_t)len >= sizeof(new_option))
goto out_err;
if (po_append(options, new_option) != PO_SUCCEEDED)
goto out_err;
return 1;
out_err:
nfs_error(_("%s: failed to construct %s option"), progname, keyword);
return 0;
}
/*
* Append the 'addr=' option to the options string to pass a resolved
* server address to the kernel. After a successful mount, this address
* is also added to /etc/mtab for use when unmounting.
*
* If 'addr=' is already present, we strip it out. This prevents users
* from setting a bogus 'addr=' option themselves, and also allows bg
* retries to recompute the server's address, in case it has changed.
*
* Returns 1 if 'addr=' option appended successfully;
* otherwise zero.
*/
static int nfs_append_addr_option(const struct sockaddr *sap,
socklen_t salen,
struct mount_options *options)
{
po_remove_all(options, "addr");
return nfs_append_generic_address_option(sap, salen, "addr", options);
}
/*
* Called to discover our address and append an appropriate 'clientaddr='
* option to the options string. If the supplied 'clientaddr=' value does
* not match either IPV4/IPv6 any or a local address, then fail the mount.
*
* Returns 1 if 'clientaddr=' option created successfully or if
* 'clientaddr=' option is already present; otherwise zero.
*/
static int nfs_append_clientaddr_option(const struct sockaddr *sap,
socklen_t salen,
struct mount_options *options)
{
union nfs_sockaddr address;
struct sockaddr *my_addr = &address.sa;
socklen_t my_len = sizeof(address);
if (po_contains(options, "clientaddr") == PO_FOUND) {
char *addr = po_get(options, "clientaddr");
union nfs_sockaddr nfs_address;
struct sockaddr *nfs_saddr = &nfs_address.sa;
socklen_t nfs_salen = sizeof(nfs_address);
/* translate the input for clientaddr to nfs_sockaddr */
if (!nfs_string_to_sockaddr(addr, nfs_saddr, &nfs_salen))
return 0;
/* check for IPV4_ANY and IPV6_ANY */
if (nfs_is_inaddr_any(nfs_saddr))
return 1;
/* check if ip matches local network addresses */
if (!nfs_addr_matches_localips(nfs_saddr))
nfs_error(_("%s: [warning] supplied clientaddr=%s "
"does not match any existing network "
"addresses"), progname, addr);
return 1;
}
nfs_callback_address(sap, salen, my_addr, &my_len);
return nfs_append_generic_address_option(my_addr, my_len,
"clientaddr", options);
}
/*
* Determine whether to append a 'mountaddr=' option. The option is needed if:
*
* 1. "mounthost=" was specified, or
* 2. The address families for proto= and mountproto= are different.
*/
static int nfs_fix_mounthost_option(struct mount_options *options,
const char *nfs_hostname)
{
union nfs_sockaddr address;
struct sockaddr *sap = &address.sa;
socklen_t salen = sizeof(address);
sa_family_t nfs_family, mnt_family;
char *mounthost;
if (!nfs_nfs_proto_family(options, &nfs_family))
return 0;
if (!nfs_mount_proto_family(options, &mnt_family))
return 0;
mounthost = po_get(options, "mounthost");
if (mounthost == NULL) {
if (nfs_family == mnt_family)
return 1;
mounthost = (char *)nfs_hostname;
}
if (!nfs_lookup(mounthost, mnt_family, sap, &salen)) {
nfs_error(_("%s: unable to determine mount server's address"),
progname);
return 0;
}
return nfs_append_generic_address_option(sap, salen,
"mountaddr", options);
}
/*
* Returns zero if the "lock" option is in effect, but statd
* can't be started. Otherwise, returns 1.
*/
static const char *nfs_lock_opttbl[] = {
"nolock",
"lock",
NULL,
};
static int nfs_verify_lock_option(struct mount_options *options)
{
if (po_rightmost(options, nfs_lock_opttbl) == 0)
return 1;
if (!start_statd()) {
nfs_error(_("%s: rpc.statd is not running but is "
"required for remote locking."), progname);
nfs_error(_("%s: Either use '-o nolock' to keep "
"locks local, or start statd."), progname);
errno = EALREADY; /* Don't print further error message */
return 0;
}
return 1;
}
static int nfs_insert_sloppy_option(struct mount_options *options)
{
if (linux_version_code() < MAKE_VERSION(2, 6, 27))
return 1;
if (po_contains(options, "sloppy")) {
po_remove_all(options, "sloppy");
sloppy++;
}
if (sloppy) {
if (po_insert(options, "sloppy") == PO_FAILED)
return 0;
}
return 1;
}
static int nfs_set_version(struct nfsmount_info *mi)
{
if (!nfs_nfs_version(mi->type, mi->options, &mi->version))
return 0;
/*
* Before 2.6.32, the kernel NFS client didn't
* support "-t nfs vers=4" mounts, so NFS version
* 4 cannot be included when autonegotiating
* while running on those kernels.
*/
if (mi->version.v_mode == V_DEFAULT &&
linux_version_code() <= MAKE_VERSION(2, 6, 31)) {
mi->version.major = 3;
mi->version.v_mode = V_SPECIFIC;
}
/*
* If we still don't know, check for version-specific
* mount options.
*/
if (mi->version.v_mode == V_DEFAULT) {
if (po_contains(mi->options, "mounthost") ||
po_contains(mi->options, "mountaddr") ||
po_contains(mi->options, "mountvers") ||
po_contains(mi->options, "mountproto")) {
mi->version.major = 3;
mi->version.v_mode = V_SPECIFIC;
}
}
/*
* If enabled, see if the default version was
* set in the config file
*/
if (mi->version.v_mode != V_SPECIFIC) {
nfs_default_version(mi);
/*
* If the version was not specifically set, it will
* be set by autonegotiation later, so remove it now:
*/
po_remove_all(mi->options, "v4");
po_remove_all(mi->options, "vers");
po_remove_all(mi->options, "nfsvers");
}
if (mi->version.v_mode == V_PARSE_ERR)
return 0;
return 1;
}
/*
* Set up mandatory non-version specific NFS mount options.
*
* Returns 1 if successful; otherwise zero.
*/
static int nfs_validate_options(struct nfsmount_info *mi)
{
/* For remount, ignore mi->spec: the kernel will. */
if (!(mi->flags & MS_REMOUNT) &&
!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
return 0;
if (!nfs_nfs_proto_family(mi->options, &mi->family))
return 0;
/*
* A remount is not going to be able to change the server's address,
* nor should we try to resolve another address for the server as we
* may end up with a different address.
* A non-remount will set 'addr' from ->hostname
*/
po_remove_all(mi->options, "addr");
if (!nfs_set_version(mi))
return 0;
if (!nfs_insert_sloppy_option(mi->options))
return 0;
return 1;
}
/*
* Get NFS/mnt server addresses from mount options
*
* Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
* if all goes well; otherwise zero.
*/
static int nfs_extract_server_addresses(struct mount_options *options,
struct sockaddr *nfs_saddr,
socklen_t *nfs_salen,
struct sockaddr *mnt_saddr,
socklen_t *mnt_salen)
{
char *option;
option = po_get(options, "addr");
if (option == NULL)
return 0;
if (!nfs_string_to_sockaddr(option, nfs_saddr, nfs_salen))
return 0;
option = po_get(options, "mountaddr");
if (option == NULL) {
memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
*mnt_salen = *nfs_salen;
} else if (!nfs_string_to_sockaddr(option, mnt_saddr, mnt_salen))
return 0;
return 1;
}
static int nfs_construct_new_options(struct mount_options *options,
struct sockaddr *nfs_saddr,
struct pmap *nfs_pmap,
struct sockaddr *mnt_saddr,
struct pmap *mnt_pmap)
{
char new_option[64];
char *netid;
po_remove_all(options, "nfsprog");
po_remove_all(options, "mountprog");
po_remove_all(options, "v2");
po_remove_all(options, "v3");
po_remove_all(options, "vers");
po_remove_all(options, "nfsvers");
snprintf(new_option, sizeof(new_option) - 1,
"vers=%lu", nfs_pmap->pm_vers);
if (po_append(options, new_option) == PO_FAILED)
return 0;
po_remove_all(options, "proto");
po_remove_all(options, "udp");
po_remove_all(options, "tcp");
netid = nfs_get_netid(nfs_saddr->sa_family, nfs_pmap->pm_prot);
if (netid == NULL)
return 0;
snprintf(new_option, sizeof(new_option) - 1,
"proto=%s", netid);
free(netid);
if (po_append(options, new_option) == PO_FAILED)
return 0;
if(po_remove_all(options, "port") == PO_FOUND ||
nfs_pmap->pm_port != NFS_PORT) {
snprintf(new_option, sizeof(new_option) - 1,
"port=%lu", nfs_pmap->pm_port);
if (po_append(options, new_option) == PO_FAILED)
return 0;
}
po_remove_all(options, "mountvers");
snprintf(new_option, sizeof(new_option) - 1,
"mountvers=%lu", mnt_pmap->pm_vers);
if (po_append(options, new_option) == PO_FAILED)
return 0;
po_remove_all(options, "mountproto");
netid = nfs_get_netid(mnt_saddr->sa_family, mnt_pmap->pm_prot);
if (netid == NULL)
return 0;
snprintf(new_option, sizeof(new_option) - 1,
"mountproto=%s", netid);
free(netid);
if (po_append(options, new_option) == PO_FAILED)
return 0;
po_remove_all(options, "mountport");
snprintf(new_option, sizeof(new_option) - 1,
"mountport=%lu", mnt_pmap->pm_port);
if (po_append(options, new_option) == PO_FAILED)
return 0;
return 1;
}
/*
* Reconstruct the mount option string based on a portmapper probe
* of the server. Returns one if the server's portmapper returned
* something we can use, otherwise zero.
*
* To handle version and transport protocol fallback properly, we
* need to parse some of the mount options in order to set up a
* portmap probe. Mount options that nfs_rewrite_pmap_mount_options()
* doesn't recognize are left alone.
*
* Returns TRUE if rewriting was successful; otherwise
* FALSE is returned if some failure occurred.
*/
static int
nfs_rewrite_pmap_mount_options(struct mount_options *options, int checkv4)
{
union nfs_sockaddr nfs_address;
struct sockaddr *nfs_saddr = &nfs_address.sa;
socklen_t nfs_salen = sizeof(nfs_address);
struct pmap nfs_pmap;
union nfs_sockaddr mnt_address;
struct sockaddr *mnt_saddr = &mnt_address.sa;
socklen_t mnt_salen = sizeof(mnt_address);
unsigned long protocol;
struct pmap mnt_pmap;
/* initialize structs */
memset(&nfs_pmap, 0, sizeof(struct pmap));
memset(&mnt_pmap, 0, sizeof(struct pmap));
/*
* Version and transport negotiation is not required
* and does not work for RDMA mounts.
*/
if (!nfs_nfs_protocol(options, &protocol)) {
errno = EINVAL;
return 0;
}
if (protocol == NFSPROTO_RDMA)
goto out;
/*
* Extract just the options needed to contact server.
* Bail now if any of these have bad values.
*/
if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
mnt_saddr, &mnt_salen)) {
errno = EINVAL;
return 0;
}
if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
errno = EINVAL;
return 0;
}
/*
* The kernel NFS client doesn't support changing the RPC
* program number for these services, so force the value of
* these fields before probing the server's ports.
*/
nfs_pmap.pm_prog = NFS_PROGRAM;
mnt_pmap.pm_prog = MOUNTPROG;
/*
* If the server's rpcbind service isn't available, we can't
* negotiate. Bail now if we can't contact it.
*/
if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
nfs_saddr, nfs_salen, &nfs_pmap, checkv4)) {
errno = ESPIPE;
if (rpc_createerr.cf_stat == RPC_PROGNOTREGISTERED)
errno = EOPNOTSUPP;
else if (rpc_createerr.cf_stat == RPC_AUTHERROR)
errno = EACCES;
else if (rpc_createerr.cf_stat == RPC_TIMEDOUT)
errno = ETIMEDOUT;
else if (rpc_createerr.cf_stat == RPC_PROGVERSMISMATCH)
errno = EPROTONOSUPPORT;
else if (rpc_createerr.cf_error.re_errno != 0)
errno = rpc_createerr.cf_error.re_errno;
return 0;
}
if (!nfs_construct_new_options(options, nfs_saddr, &nfs_pmap,
mnt_saddr, &mnt_pmap)) {
if (rpc_createerr.cf_stat == RPC_UNKNOWNPROTO)
errno = EPROTONOSUPPORT;
else
errno = EINVAL;
return 0;
}
out:
errno = 0;
return 1;
}
/*
* Do the mount(2) system call.
*
* Returns TRUE if successful, otherwise FALSE.
* "errno" is set to reflect the individual error.
*/
static int nfs_sys_mount(struct nfsmount_info *mi, struct mount_options *opts)
{
char *options = NULL;
int result;
if (mi->fake)
return 1;
if (po_join(opts, &options) == PO_FAILED) {
errno = EIO;
return 0;
}
result = mount(mi->spec, mi->node, mi->type,
mi->flags & ~(MS_USER|MS_USERS), options);
free(options);
if (verbose && result) {
int save = errno;
nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
errno = save;
}
return !result;
}
static int nfs_do_mount_v3v2(struct nfsmount_info *mi,
struct sockaddr *sap, socklen_t salen,
int checkv4)
{
struct mount_options *options = po_dup(mi->options);
int result = 0;
if (!options) {
errno = ENOMEM;
return result;
}
errno = 0;
if (!nfs_append_addr_option(sap, salen, options)) {
if (errno == 0)
errno = EINVAL;
goto out_fail;
}
if (!nfs_fix_mounthost_option(options, mi->hostname)) {
if (errno == 0)
errno = EINVAL;
goto out_fail;
}
if (!mi->fake && !nfs_verify_lock_option(options)) {
if (errno == 0)
errno = EINVAL;
goto out_fail;
}
/*
* Options we negotiate below may be stale by the time this
* file system is unmounted. In order to force umount.nfs
* to renegotiate with the server, only write the user-
* specified options, and not negotiated options, to /etc/mtab.
*/
if (po_join(options, mi->extra_opts) == PO_FAILED) {
errno = ENOMEM;
goto out_fail;
}
if (verbose)
printf(_("%s: trying text-based options '%s'\n"),
progname, *mi->extra_opts);
if (!nfs_rewrite_pmap_mount_options(options, checkv4))
goto out_fail;
result = nfs_sys_mount(mi, options);
out_fail:
po_destroy(options);
return result;
}
/*
* Attempt a "-t nfs vers=2" or "-t nfs vers=3" mount.
*
* Returns TRUE if successful, otherwise FALSE.
* "errno" is set to reflect the individual error.
*/
static int nfs_try_mount_v3v2(struct nfsmount_info *mi, int checkv4)
{
struct addrinfo *ai;
int ret = 0;
for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
ret = nfs_do_mount_v3v2(mi, ai->ai_addr, ai->ai_addrlen, checkv4);
if (ret != 0)
return ret;
switch (errno) {
case ECONNREFUSED:
case EOPNOTSUPP:
case EHOSTUNREACH:
case ETIMEDOUT:
case EACCES:
continue;
default:
goto out;
}
}
out:
return ret;
}
static int nfs_do_mount_v4(struct nfsmount_info *mi,
struct sockaddr *sap, socklen_t salen)
{
struct mount_options *options = po_dup(mi->options);
int result = 0;
char version_opt[32];
char *extra_opts = NULL;
if (!options) {
errno = ENOMEM;
return result;
}
if (po_contains(options, "mounthost") ||
po_contains(options, "mountaddr") ||
po_contains(options, "mountvers") ||
po_contains(options, "mountport") ||
po_contains(options, "mountproto")) {
/*
* Since these mountd options are set assume version 3
* is wanted so error out with EPROTONOSUPPORT so the
* protocol negation starts with v3.
*/
if (verbose) {
printf(_("%s: Unsupported nfs4 mount option(s) passed '%s'\n"),
progname, *mi->extra_opts);
}
errno = EPROTONOSUPPORT;
goto out_fail;
}
if (mi->version.v_mode != V_SPECIFIC) {
char *fmt;
switch (mi->version.minor) {
/* Old kernels don't support the new "vers=x.y"
* option, but do support old versions of NFS4.
* So use the format that is most widely understood.
*/
case 0:
fmt = "vers=%lu";
break;
case 1:
fmt = "vers=%lu,minorversion=%lu";
break;
default:
fmt = "vers=%lu.%lu";
break;
}
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
snprintf(version_opt, sizeof(version_opt) - 1,
fmt, mi->version.major,
mi->version.minor);
#pragma GCC diagnostic warning "-Wformat-nonliteral"
if (po_append(options, version_opt) == PO_FAILED) {
errno = EINVAL;
goto out_fail;
}
} else if (po_get(options, "minorversion") &&
linux_version_code() > MAKE_VERSION(3, 4, 0)) {
/*
* convert minorversion= into vers=4.x
*/
po_remove_all(options, "minorversion");
snprintf(version_opt, sizeof(version_opt) - 1,
"vers=%lu.%lu", mi->version.major,
mi->version.minor);
if (po_append(options, version_opt) == PO_FAILED) {
errno = EINVAL;
goto out_fail;
}
}
if (!nfs_append_addr_option(sap, salen, options)) {
errno = EINVAL;
goto out_fail;
}
if (!nfs_append_clientaddr_option(sap, salen, options)) {
errno = EINVAL;
goto out_fail;
}
if (po_join(options, &extra_opts) == PO_FAILED) {
errno = ENOMEM;
goto out_fail;
}
if (verbose)
printf(_("%s: trying text-based options '%s'\n"),
progname, extra_opts);
result = nfs_sys_mount(mi, options);
/*
* If success, update option string to be recorded in /etc/mtab.
*/
if (result) {
free(*mi->extra_opts);
*mi->extra_opts = extra_opts;
} else
free(extra_opts);
out_fail:
po_destroy(options);
return result;
}
/*
* Attempt a "-t nfs -o vers=4" or "-t nfs4" mount.
*
* Returns TRUE if successful, otherwise FALSE.
* "errno" is set to reflect the individual error.
*/
static int nfs_try_mount_v4(struct nfsmount_info *mi)
{
struct addrinfo *ai;
int ret = 0;
for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
ret = nfs_do_mount_v4(mi, ai->ai_addr, ai->ai_addrlen);
if (ret != 0)
return ret;
switch (errno) {
case ECONNREFUSED:
case EHOSTUNREACH:
case ETIMEDOUT:
case EACCES:
continue;
default:
goto out;
}
}
out:
return ret;
}
/*
* Handle NFS version and transport protocol
* autonegotiation.
*
* When no version or protocol is specified on the
* command line, mount.nfs negotiates with the server
* to determine appropriate settings for the new
* mount point.
*
* Returns TRUE if successful, otherwise FALSE.
* "errno" is set to reflect the individual error.
*/
static int nfs_autonegotiate(struct nfsmount_info *mi)
{
int result, olderrno;
result = nfs_try_mount_v4(mi);
check_result:
if (result)
return result;
switch (errno) {
case EPROTONOSUPPORT:
/* A clear indication that the server or our
* client does not support NFS version 4 and minor */
case EINVAL:
/* A less clear indication that our client
* does not support NFSv4 minor version. */
case EACCES:
/* An unclear indication that the server
* may not support NFSv4 minor version. */
if (mi->version.v_mode != V_SPECIFIC) {
if (mi->version.minor > 0) {
mi->version.minor--;
result = nfs_try_mount_v4(mi);
goto check_result;
}
}
goto fall_back;
case ENOENT:
/* Legacy Linux servers don't export an NFS
* version 4 pseudoroot. */
goto fall_back;
case EPERM:
/* Linux servers prior to 2.6.25 may return
* EPERM when NFS version 4 is not supported. */
goto fall_back;
case ECONNREFUSED:
/* UDP-Only servers won't support v4, but maybe it
* just isn't ready yet. So try v3, but double-check
* with rpcbind for v4. */
if (mi->version.v_mode == V_GENERAL)
/* Mustn't try v2,v3 */
return result;
result = nfs_try_mount_v3v2(mi, TRUE);
if (result == 0 && errno == EAGAIN) {
/* v4 server seems to be registered now. */
result = nfs_try_mount_v4(mi);
if (result == 0 && errno != ECONNREFUSED)
goto check_result;
} else if (result == 0)
/* Restore original errno with v3 failures */
errno = ECONNREFUSED;
return result;
default:
return result;
}
fall_back:
if (mi->version.v_mode == V_GENERAL)
/* v2,3 fallback not allowed */
return result;
/*
* Save the original errno in case the v3
* mount fails from one of the fall_back cases.
* Report the first failure not the v3 mount failure
*/
olderrno = errno;
if ((result = nfs_try_mount_v3v2(mi, FALSE)))
return result;
if (errno != EBUSY)
errno = olderrno;
return result;
}
/*
* This is a single pass through the fg/bg loop.
*
* Returns TRUE if successful, otherwise FALSE.
* "errno" is set to reflect the individual error.
*/
static int nfs_try_mount(struct nfsmount_info *mi)
{
int result = 0;
if (mi->address == NULL) {
struct addrinfo hint = {
.ai_protocol = (int)IPPROTO_UDP,
};
int error;
struct addrinfo *address;
hint.ai_family = (int)mi->family;
error = getaddrinfo(mi->hostname, NULL, &hint, &address);
if (error != 0) {
if (error == EAI_AGAIN)
errno = EAGAIN;
else {
nfs_error(_("%s: Failed to resolve server %s: %s"),
progname, mi->hostname, gai_strerror(error));
errno = EALREADY;
}
return 0;
}
if (!nfs_append_addr_option(address->ai_addr,
address->ai_addrlen, mi->options)) {
nfs_freeaddrinfo(address);
errno = ENOMEM;
return 0;
}
mi->address = address;
}
switch (mi->version.major) {
case 3:
result = nfs_try_mount_v3v2(mi, FALSE);
break;
case 4:
if (mi->version.v_mode != V_SPECIFIC)
result = nfs_autonegotiate(mi);
else
result = nfs_try_mount_v4(mi);
break;
default:
errno = EIO;
}
return result;
}
/*
* Distinguish between permanent and temporary errors.
*
* Basically, we retry if communication with the server has
* failed so far, but fail immediately if there is a local
* error (like a bad mount option).
*
* If there is a remote error, like ESTALE or RPC_PROGNOTREGISTERED
* then it is probably permanent, but there is a small chance
* the it is temporary can we caught the server at an awkward
* time during start-up. So require that we see three of those
* before treating them as permanent.
* For ECONNREFUSED, wait a bit longer as there is often a longer
* gap between the network being ready and the NFS server starting.
*
* Returns 1 if we should fail immediately, or 0 if we
* should retry.
*/
static int nfs_is_permanent_error(int error)
{
static int prev_error;
static int rpt_cnt;
if (error == prev_error)
rpt_cnt += 1;
else
rpt_cnt = 1;
prev_error = error;
switch (error) {
case ESTALE:
case EOPNOTSUPP: /* aka RPC_PROGNOTREGISTERED */
/* If two in a row, assume permanent */
return rpt_cnt >= 3;
case ECONNREFUSED:
/* Like the above, this can be temporary during a
* small window. However it is typically a larger
* window than for the others, and we have historically
* treated this as a temporary (i.e. long timeout)
* error with no complaints, so continue to treat
* it as temporary.
*/
return 0; /* temporary */
case ETIMEDOUT:
case EHOSTUNREACH:
case EAGAIN:
return 0; /* temporary */
default:
return 1; /* permanent */
}
}
/*
* Handle "foreground" NFS mounts.
*
* Retry the mount request for as long as the 'retry=' option says.
*
* Returns a valid mount command exit code.
*/
static int nfsmount_fg(struct nfsmount_info *mi)
{
unsigned int secs = 1;
time_t timeout;
timeout = nfs_parse_retry_option(mi->options,
NFS_DEF_FG_TIMEOUT_MINUTES);
if (verbose)
printf(_("%s: timeout set for %s"),
progname, ctime(&timeout));
for (;;) {
if (nfs_try_mount(mi))
return EX_SUCCESS;
if (errno == EBUSY && is_mountpoint(mi->node)) {
/*
* EBUSY can happen when mounting a filesystem that
* is already mounted or when the context= are
* different when using the -o sharecache
*
* Only error out in the latter case.
*/
return EX_SUCCESS;
}
if (nfs_is_permanent_error(errno))
break;
if (time(NULL) > timeout)
break;
if (errno != ETIMEDOUT) {
if (sleep(secs))
break;
secs <<= 1;
if (secs > 10)
secs = 10;
}
}
mount_error(mi->spec, mi->node, errno);
return EX_FAIL;
}
/*
* Handle "background" NFS mount [first try]
*
* Returns a valid mount command exit code.
*
* EX_BG should cause the caller to fork and invoke nfsmount_child.
*/
static int nfsmount_parent(struct nfsmount_info *mi)
{
if (nfs_try_mount(mi))
return EX_SUCCESS;
if (nfs_is_permanent_error(errno)) {
mount_error(mi->spec, mi->node, errno);
return EX_FAIL;
}
sys_mount_errors(mi->hostname, errno, 1, 1);
return EX_BG;
}
/*
* Handle "background" NFS mount [retry daemon]
*
* Returns a valid mount command exit code: EX_SUCCESS if successful,
* EX_FAIL if a failure occurred. There's nothing to catch the
* error return, though, so we use sys_mount_errors to log the
* failure.
*/
static int nfsmount_child(struct nfsmount_info *mi)
{
unsigned int secs = 1;
time_t timeout;
timeout = nfs_parse_retry_option(mi->options,
NFS_DEF_BG_TIMEOUT_MINUTES);
for (;;) {
if (sleep(secs))
break;
secs <<= 1;
if (secs > 120)
secs = 120;
if (nfs_try_mount(mi))
return EX_SUCCESS;
if (nfs_is_permanent_error(errno))
break;
if (time(NULL) > timeout)
break;
sys_mount_errors(mi->hostname, errno, 1, 1);
};
sys_mount_errors(mi->hostname, errno, 1, 0);
return EX_FAIL;
}
/*
* Handle "background" NFS mount
*
* Returns a valid mount command exit code.
*/
static int nfsmount_bg(struct nfsmount_info *mi)
{
if (!mi->child)
return nfsmount_parent(mi);
else
return nfsmount_child(mi);
}
/*
* Usually all that is needed for an NFS remount is to change
* generic mount options like "sync" or "ro". These generic
* options are controlled by mi->flags, not by text-based
* options, and no contact with the server is needed.
*
* Take care with the /etc/mtab entry for this mount; just
* calling update_mtab() will change an "-t nfs -o vers=4"
* mount to an "-t nfs -o remount" mount, and that will
* confuse umount.nfs.
*
* Returns a valid mount command exit code.
*/
static int nfs_remount(struct nfsmount_info *mi)
{
if (nfs_sys_mount(mi, mi->options))
return EX_SUCCESS;
mount_error(mi->spec, mi->node, errno);
return EX_FAIL;
}
/*
* Process mount options and try a mount system call.
*
* Returns a valid mount command exit code.
*/
static const char *nfs_background_opttbl[] = {
"bg",
"fg",
NULL,
};
static int nfsmount_start(struct nfsmount_info *mi)
{
if (!nfs_validate_options(mi))
return EX_FAIL;
/*
* NFS v2 has been deprecated
*/
if (mi->version.major == 2) {
mount_error(mi->spec, mi->node, EOPNOTSUPP);
return EX_FAIL;
}
/*
* Avoid retry and negotiation logic when remounting
*/
if (mi->flags & MS_REMOUNT)
return nfs_remount(mi);
if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
return nfsmount_bg(mi);
else
return nfsmount_fg(mi);
}
/**
* nfsmount_string - Mount an NFS file system using C string options
* @spec: C string specifying remote share to mount ("hostname:path")
* @node: C string pathname of local mounted-on directory
* @type: C string that represents file system type ("nfs" or "nfs4")
* @flags: MS_ style mount flags
* @extra_opts: pointer to C string containing fs-specific mount options
* (input and output argument)
* @fake: flag indicating whether to carry out the whole operation
* @child: one if this is a mount daemon (bg)
*
* Returns a valid mount command exit code.
*/
int nfsmount_string(const char *spec, const char *node, char *type,
int flags, char **extra_opts, int fake, int child)
{
struct nfsmount_info mi = {
.spec = spec,
.node = node,
.address = NULL,
.type = type,
.extra_opts = extra_opts,
.flags = flags,
.fake = fake,
.child = child,
};
int retval = EX_FAIL;
mi.options = po_split(*extra_opts);
if (mi.options) {
retval = nfsmount_start(&mi);
po_destroy(mi.options);
} else
nfs_error(_("%s: internal option parsing error"), progname);
nfs_freeaddrinfo(mi.address);
free(mi.hostname);
return retval;
}