/* * stropts.c -- NFS mount using C string to pass options to kernel * * Copyright (C) 2007 Oracle. All rights reserved. * Copyright (C) 2007 Chuck Lever * * 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., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include "xcommon.h" #include "mount.h" #include "nls.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" #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 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 */ *type; /* "nfs" or "nfs4" */ char *hostname; /* server's hostname */ struct mount_options *options; /* parsed mount options */ char **extra_opts; /* string for /etc/mtab */ int flags, /* MS_ flags */ fake, /* actually do the mount? */ child; /* forked bg child? */ sa_family_t family; /* supported address family */ }; /* * 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, unsigned int timeout_minutes) { long tmp; switch (po_get_numeric(options, "retry", &tmp)) { case PO_NOT_FOUND: break; case PO_FOUND: if (tmp >= 0) { timeout_minutes = tmp; break; } case PO_BAD_VALUE: if (verbose) nfs_error(_("%s: invalid retry timeout was specified; " "using default timeout"), progname); break; } return time(NULL) + (time_t)(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]; if (!nfs_present_sockaddr(sap, salen, address, sizeof(address))) goto out_err; if (snprintf(new_option, sizeof(new_option), "%s=%s", keyword, address) >= 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. * * 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) { struct sockaddr_storage dummy; struct sockaddr *my_addr = (struct sockaddr *)&dummy; socklen_t my_len = sizeof(dummy); if (po_contains(options, "clientaddr") == PO_FOUND) return 1; nfs_callback_address(sap, salen, my_addr, &my_len); return nfs_append_generic_address_option(my_addr, my_len, "clientaddr", options); } /* * Resolve the 'mounthost=' hostname and append a new option using * the resulting address. */ static int nfs_fix_mounthost_option(const sa_family_t family, struct mount_options *options) { struct sockaddr_storage dummy; struct sockaddr *sap = (struct sockaddr *)&dummy; socklen_t salen = sizeof(dummy); char *mounthost; mounthost = po_get(options, "mounthost"); if (!mounthost) return 1; if (!nfs_name_to_address(mounthost, 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) == 1) 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); return 0; } return 1; } static int nfs_append_sloppy_option(struct mount_options *options) { if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27)) return 1; if (po_append(options, "sloppy") == PO_FAILED) return 0; return 1; } /* * Set up mandatory NFS mount options. * * Returns 1 if successful; otherwise zero. */ static int nfs_validate_options(struct nfsmount_info *mi) { struct sockaddr_storage dummy; struct sockaddr *sap = (struct sockaddr *)&dummy; socklen_t salen = sizeof(dummy); if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL)) return 0; if (!nfs_name_to_address(mi->hostname, mi->family, sap, &salen)) return 0; if (strncmp(mi->type, "nfs4", 4) == 0) { if (!nfs_append_clientaddr_option(sap, salen, mi->options)) return 0; } else { if (!nfs_fix_mounthost_option(mi->family, mi->options)) return 0; if (!mi->fake && !nfs_verify_lock_option(mi->options)) return 0; } if (!nfs_append_sloppy_option(mi->options)) return 0; return nfs_append_addr_option(sap, salen, mi->options); } /* * Distinguish between permanent and temporary errors. * * Returns 0 if the passed-in error is temporary, thus the * mount system call should be retried; returns one if the * passed-in error is permanent, thus the mount system call * should not be retried. */ static int nfs_is_permanent_error(int error) { switch (error) { case ESTALE: case ETIMEDOUT: case ECONNREFUSED: return 0; /* temporary */ default: return 1; /* permanent */ } } /* * 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_mount_options() * doesn't recognize are left alone. * * Returns a new group of mount options if successful; otherwise * NULL is returned if some failure occurred. */ static const char *nfs_transport_opttbl[] = { "udp", "tcp", NULL, }; static struct mount_options *nfs_rewrite_mount_options(char *str) { struct mount_options *options; char *option, new_option[64]; clnt_addr_t mnt_server = { }; clnt_addr_t nfs_server = { }; int p; options = po_split(str); if (!options) { errno = EFAULT; return NULL; } errno = EINVAL; option = po_get(options, "addr"); if (option) { nfs_server.saddr.sin_family = AF_INET; if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr)) goto err; } else goto err; option = po_get(options, "mountaddr"); if (option) { mnt_server.saddr.sin_family = AF_INET; if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr)) goto err; } else memcpy(&mnt_server.saddr, &nfs_server.saddr, sizeof(mnt_server.saddr)); option = po_get(options, "mountport"); if (option) mnt_server.pmap.pm_port = atoi(option); mnt_server.pmap.pm_prog = MOUNTPROG; option = po_get(options, "mountvers"); if (option) mnt_server.pmap.pm_vers = atoi(option); option = po_get(options, "mountproto"); if (option) { if (strcmp(option, "tcp") == 0) { mnt_server.pmap.pm_prot = IPPROTO_TCP; po_remove_all(options, "mountproto"); } if (strcmp(option, "udp") == 0) { mnt_server.pmap.pm_prot = IPPROTO_UDP; po_remove_all(options, "mountproto"); } } option = po_get(options, "port"); if (option) { nfs_server.pmap.pm_port = atoi(option); po_remove_all(options, "port"); } nfs_server.pmap.pm_prog = NFS_PROGRAM; option = po_get(options, "nfsvers"); if (option) { nfs_server.pmap.pm_vers = atoi(option); po_remove_all(options, "nfsvers"); } option = po_get(options, "vers"); if (option) { nfs_server.pmap.pm_vers = atoi(option); po_remove_all(options, "vers"); } option = po_get(options, "proto"); if (option) { if (strcmp(option, "tcp") == 0) { nfs_server.pmap.pm_prot = IPPROTO_TCP; po_remove_all(options, "proto"); } if (strcmp(option, "udp") == 0) { nfs_server.pmap.pm_prot = IPPROTO_UDP; po_remove_all(options, "proto"); } } p = po_rightmost(options, nfs_transport_opttbl); switch (p) { case 1: nfs_server.pmap.pm_prot = IPPROTO_UDP; break; case 2: nfs_server.pmap.pm_prot = IPPROTO_TCP; break; } po_remove_all(options, "tcp"); po_remove_all(options, "udp"); if (!probe_bothports(&mnt_server, &nfs_server)) { errno = ESPIPE; goto err; } snprintf(new_option, sizeof(new_option) - 1, "nfsvers=%lu", nfs_server.pmap.pm_vers); if (po_append(options, new_option) == PO_FAILED) goto err; if (nfs_server.pmap.pm_prot == IPPROTO_TCP) snprintf(new_option, sizeof(new_option) - 1, "proto=tcp"); else snprintf(new_option, sizeof(new_option) - 1, "proto=udp"); if (po_append(options, new_option) == PO_FAILED) goto err; if (nfs_server.pmap.pm_port != NFS_PORT) { snprintf(new_option, sizeof(new_option) - 1, "port=%lu", nfs_server.pmap.pm_port); if (po_append(options, new_option) == PO_FAILED) goto err; } if (mnt_server.pmap.pm_prot == IPPROTO_TCP) snprintf(new_option, sizeof(new_option) - 1, "mountproto=tcp"); else snprintf(new_option, sizeof(new_option) - 1, "mountproto=udp"); if (po_append(options, new_option) == PO_FAILED) goto err; snprintf(new_option, sizeof(new_option) - 1, "mountport=%lu", mnt_server.pmap.pm_port); if (po_append(options, new_option) == PO_FAILED) goto err; errno = 0; return options; err: po_destroy(options); return NULL; } /* * Do the mount(2) system call. * * Returns 1 if successful, otherwise zero. * "errno" is set to reflect the individual error. */ static int nfs_sys_mount(const struct nfsmount_info *mi, const char *type, const char *options) { int result; result = mount(mi->spec, mi->node, type, mi->flags & ~(MS_USER|MS_USERS), options); if (verbose && result) { int save = errno; nfs_error(_("%s: mount(2): %s"), progname, strerror(save)); errno = save; } return !result; } /* * Retry an NFS mount that failed because the requested service isn't * available on the server. * * Returns 1 if successful. Otherwise, returns zero. * "errno" is set to reflect the individual error. * * Side effect: If the retry is successful, both 'options' and * 'extra_opts' are updated to reflect the mount options that worked. * If the retry fails, 'options' and 'extra_opts' are left unchanged. */ static int nfs_retry_nfs23mount(struct nfsmount_info *mi) { struct mount_options *retry_options; char *retry_str = NULL; char **extra_opts = mi->extra_opts; retry_options = nfs_rewrite_mount_options(*extra_opts); if (!retry_options) return 0; if (po_join(retry_options, &retry_str) == PO_FAILED) { po_destroy(retry_options); errno = EIO; return 0; } if (verbose) printf(_("%s: text-based options (retry): '%s'\n"), progname, retry_str); if (!nfs_sys_mount(mi, "nfs", retry_str)) { po_destroy(retry_options); free(retry_str); return 0; } free(*extra_opts); *extra_opts = retry_str; po_replace(mi->options, retry_options); return 1; } /* * Attempt an NFSv2/3 mount via a mount(2) system call. If the kernel * claims the requested service isn't supported on the server, probe * the server to see what's supported, rewrite the mount options, * and retry the request. * * Returns 1 if successful. Otherwise, returns zero. * "errno" is set to reflect the individual error. * * Side effect: If the retry is successful, both 'options' and * 'extra_opts' are updated to reflect the mount options that worked. * If the retry fails, 'options' and 'extra_opts' are left unchanged. */ static int nfs_try_nfs23mount(struct nfsmount_info *mi) { char **extra_opts = mi->extra_opts; if (po_join(mi->options, extra_opts) == PO_FAILED) { errno = EIO; return 0; } if (verbose) printf(_("%s: text-based options: '%s'\n"), progname, *extra_opts); if (mi->fake) return 1; if (nfs_sys_mount(mi, "nfs", *extra_opts)) return 1; /* * The kernel returns EOPNOTSUPP if the RPC bind failed, * and EPROTONOSUPPORT if the version isn't supported. */ if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT) return 0; return nfs_retry_nfs23mount(mi); } /* * Attempt an NFS v4 mount via a mount(2) system call. * * Returns 1 if successful. Otherwise, returns zero. * "errno" is set to reflect the individual error. */ static int nfs_try_nfs4mount(struct nfsmount_info *mi) { char **extra_opts = mi->extra_opts; if (po_join(mi->options, extra_opts) == PO_FAILED) { errno = EIO; return 0; } if (verbose) printf(_("%s: text-based options: '%s'\n"), progname, *extra_opts); if (mi->fake) return 1; return nfs_sys_mount(mi, "nfs4", *extra_opts); } /* * Perform either an NFSv2/3 mount, or an NFSv4 mount system call. * * Returns 1 if successful. Otherwise, returns zero. * "errno" is set to reflect the individual error. */ static int nfs_try_mount(struct nfsmount_info *mi) { if (strncmp(mi->type, "nfs4", 4) == 0) return nfs_try_nfs4mount(mi); else return nfs_try_nfs23mount(mi); } /* * 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 (nfs_is_permanent_error(errno)) break; if (time(NULL) > timeout) { errno = ETIMEDOUT; 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); } /* * 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; if (po_rightmost(mi->options, nfs_background_opttbl) == 1) 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) */ int nfsmount_string(const char *spec, const char *node, const char *type, int flags, char **extra_opts, int fake, int child) { struct nfsmount_info mi = { .spec = spec, .node = node, .type = type, .extra_opts = extra_opts, .flags = flags, .fake = fake, .child = child, #ifdef IPV6_SUPPORTED .family = AF_UNSPEC, /* either IPv4 or v6 */ #else .family = AF_INET, /* only IPv4 */ #endif }; 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); free(mi.hostname); return retval; }