diff options
Diffstat (limited to 'utils/mount/stropts.c')
| -rw-r--r-- | utils/mount/stropts.c | 1310 |
1 files changed, 1310 insertions, 0 deletions
diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c new file mode 100644 index 0000000..dbdd11e --- /dev/null +++ b/utils/mount/stropts.c @@ -0,0 +1,1310 @@ +/* + * 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 != EACCES) + 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; +} |