/* * Copyright (c) 2007 Pawel Jakub Dawidek * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``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 THE AUTHORS OR CONTRIBUTORS 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. * * Copyright (c) 2020 by Delphix. All rights reserved. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include "libzfs_impl.h" #include "libshare_impl.h" #include "nfs.h" #define _PATH_MOUNTDPID "/var/run/mountd.pid" #define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n" #define OPTSSIZE 1024 #define MAXLINESIZE (PATH_MAX + OPTSSIZE) #define ZFS_EXPORTS_FILE "/etc/zfs/exports" #define ZFS_EXPORTS_LOCK ZFS_EXPORTS_FILE".lock" static sa_fstype_t *nfs_fstype; static int nfs_lock_fd = -1; /* * The nfs_exports_[lock|unlock] is used to guard against conconcurrent * updates to the exports file. Each protocol is responsible for * providing the necessary locking to ensure consistency. */ static int nfs_exports_lock(void) { int err; nfs_lock_fd = open(ZFS_EXPORTS_LOCK, O_RDWR | O_CREAT | O_CLOEXEC, 0600); if (nfs_lock_fd == -1) { err = errno; fprintf(stderr, "failed to lock %s: %s\n", ZFS_EXPORTS_LOCK, strerror(err)); return (err); } if (flock(nfs_lock_fd, LOCK_EX) != 0) { err = errno; fprintf(stderr, "failed to lock %s: %s\n", ZFS_EXPORTS_LOCK, strerror(err)); (void) close(nfs_lock_fd); return (err); } return (0); } static void nfs_exports_unlock(void) { verify(nfs_lock_fd > 0); if (flock(nfs_lock_fd, LOCK_UN) != 0) { fprintf(stderr, "failed to unlock %s: %s\n", ZFS_EXPORTS_LOCK, strerror(errno)); } close(nfs_lock_fd); nfs_lock_fd = -1; } /* * Read one line from a file. Skip comments, empty lines and a line with a * mountpoint specified in the 'skip' argument. * * NOTE: This function returns a static buffer and thus is not thread-safe. */ static char * zgetline(FILE *fd, const char *skip) { static char line[MAXLINESIZE]; size_t len, skiplen = 0; char *s, last; if (skip != NULL) skiplen = strlen(skip); for (;;) { s = fgets(line, sizeof (line), fd); if (s == NULL) return (NULL); /* Skip empty lines and comments. */ if (line[0] == '\n' || line[0] == '#') continue; len = strlen(line); if (line[len - 1] == '\n') line[len - 1] = '\0'; last = line[skiplen]; /* Skip the given mountpoint. */ if (skip != NULL && strncmp(skip, line, skiplen) == 0 && (last == '\t' || last == ' ' || last == '\0')) { continue; } break; } return (line); } /* * This function translate options to a format acceptable by exports(5), eg. * * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \ * zfs.freebsd.org 69.147.83.54 * * Accepted input formats: * * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,zfs.freebsd.org * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 zfs.freebsd.org * -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,zfs.freebsd.org * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \ * zfs.freebsd.org * * Recognized keywords: * * ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs, * index, quiet * * NOTE: This function returns a static buffer and thus is not thread-safe. */ static char * translate_opts(const char *shareopts) { static const char *known_opts[] = { "ro", "maproot", "mapall", "mask", "network", "sec", "alldirs", "public", "webnfs", "index", "quiet", NULL }; static char newopts[OPTSSIZE]; char oldopts[OPTSSIZE]; char *o, *s = NULL; unsigned int i; size_t len; strlcpy(oldopts, shareopts, sizeof (oldopts)); newopts[0] = '\0'; s = oldopts; while ((o = strsep(&s, "-, ")) != NULL) { if (o[0] == '\0') continue; for (i = 0; known_opts[i] != NULL; i++) { len = strlen(known_opts[i]); if (strncmp(known_opts[i], o, len) == 0 && (o[len] == '\0' || o[len] == '=')) { strlcat(newopts, "-", sizeof (newopts)); break; } } strlcat(newopts, o, sizeof (newopts)); strlcat(newopts, " ", sizeof (newopts)); } return (newopts); } static char * nfs_init_tmpfile(void) { char *tmpfile = NULL; if (asprintf(&tmpfile, "%s%s", ZFS_EXPORTS_FILE, ".XXXXXXXX") == -1) { fprintf(stderr, "Unable to allocate buffer for temporary " "file name\n"); return (NULL); } int fd = mkstemp(tmpfile); if (fd == -1) { fprintf(stderr, "Unable to create temporary file: %s", strerror(errno)); free(tmpfile); return (NULL); } close(fd); return (tmpfile); } static int nfs_fini_tmpfile(char *tmpfile) { if (rename(tmpfile, ZFS_EXPORTS_FILE) == -1) { fprintf(stderr, "Unable to rename %s: %s\n", tmpfile, strerror(errno)); unlink(tmpfile); free(tmpfile); return (SA_SYSTEM_ERR); } free(tmpfile); return (SA_OK); } /* * This function copies all entries from the exports file to "filename", * omitting any entries for the specified mountpoint. */ static int nfs_copy_entries(char *filename, const char *mountpoint) { int error = SA_OK; char *line; FILE *oldfp = fopen(ZFS_EXPORTS_FILE, "re"); FILE *newfp = fopen(filename, "w+e"); if (newfp == NULL) { fprintf(stderr, "failed to open %s file: %s", filename, strerror(errno)); fclose(oldfp); return (SA_SYSTEM_ERR); } fputs(FILE_HEADER, newfp); /* * The ZFS_EXPORTS_FILE may not exist yet. If that's the * case then just write out the new file. */ if (oldfp != NULL) { while ((line = zgetline(oldfp, mountpoint)) != NULL) fprintf(newfp, "%s\n", line); if (ferror(oldfp) != 0) { error = ferror(oldfp); } if (fclose(oldfp) != 0) { fprintf(stderr, "Unable to close file %s: %s\n", filename, strerror(errno)); error = error != 0 ? error : SA_SYSTEM_ERR; } } if (error == 0 && ferror(newfp) != 0) { error = ferror(newfp); } if (fclose(newfp) != 0) { fprintf(stderr, "Unable to close file %s: %s\n", filename, strerror(errno)); error = error != 0 ? error : SA_SYSTEM_ERR; } return (error); } static int nfs_enable_share(sa_share_impl_t impl_share) { char *filename = NULL; int error; if ((filename = nfs_init_tmpfile()) == NULL) return (SA_SYSTEM_ERR); error = nfs_exports_lock(); if (error != 0) { unlink(filename); free(filename); return (error); } error = nfs_copy_entries(filename, impl_share->sa_mountpoint); if (error != SA_OK) { unlink(filename); free(filename); nfs_exports_unlock(); return (error); } FILE *fp = fopen(filename, "a+e"); if (fp == NULL) { fprintf(stderr, "failed to open %s file: %s", filename, strerror(errno)); unlink(filename); free(filename); nfs_exports_unlock(); return (SA_SYSTEM_ERR); } char *shareopts = FSINFO(impl_share, nfs_fstype)->shareopts; if (strcmp(shareopts, "on") == 0) shareopts = ""; if (fprintf(fp, "%s\t%s\n", impl_share->sa_mountpoint, translate_opts(shareopts)) < 0) { fprintf(stderr, "failed to write to %s\n", filename); fclose(fp); unlink(filename); free(filename); nfs_exports_unlock(); return (SA_SYSTEM_ERR); } if (fclose(fp) != 0) { fprintf(stderr, "Unable to close file %s: %s\n", filename, strerror(errno)); unlink(filename); free(filename); nfs_exports_unlock(); return (SA_SYSTEM_ERR); } error = nfs_fini_tmpfile(filename); nfs_exports_unlock(); return (error); } static int nfs_disable_share(sa_share_impl_t impl_share) { int error; char *filename = NULL; if ((filename = nfs_init_tmpfile()) == NULL) return (SA_SYSTEM_ERR); error = nfs_exports_lock(); if (error != 0) { unlink(filename); free(filename); return (error); } error = nfs_copy_entries(filename, impl_share->sa_mountpoint); if (error != SA_OK) { unlink(filename); free(filename); nfs_exports_unlock(); return (error); } error = nfs_fini_tmpfile(filename); nfs_exports_unlock(); return (error); } /* * NOTE: This function returns a static buffer and thus is not thread-safe. */ static boolean_t nfs_is_shared(sa_share_impl_t impl_share) { static char line[MAXLINESIZE]; char *s, last; size_t len; char *mntpoint = impl_share->sa_mountpoint; size_t mntlen = strlen(mntpoint); FILE *fp = fopen(ZFS_EXPORTS_FILE, "re"); if (fp == NULL) return (B_FALSE); for (;;) { s = fgets(line, sizeof (line), fp); if (s == NULL) return (B_FALSE); /* Skip empty lines and comments. */ if (line[0] == '\n' || line[0] == '#') continue; len = strlen(line); if (line[len - 1] == '\n') line[len - 1] = '\0'; last = line[mntlen]; /* Skip the given mountpoint. */ if (strncmp(mntpoint, line, mntlen) == 0 && (last == '\t' || last == ' ' || last == '\0')) { fclose(fp); return (B_TRUE); } } fclose(fp); return (B_FALSE); } static int nfs_validate_shareopts(const char *shareopts) { return (SA_OK); } static int nfs_update_shareopts(sa_share_impl_t impl_share, const char *shareopts) { FSINFO(impl_share, nfs_fstype)->shareopts = (char *)shareopts; return (SA_OK); } static void nfs_clear_shareopts(sa_share_impl_t impl_share) { FSINFO(impl_share, nfs_fstype)->shareopts = NULL; } /* * Commit the shares by restarting mountd. */ static int nfs_commit_shares(void) { struct pidfh *pfh; pid_t mountdpid; pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid); if (pfh != NULL) { /* Mountd is not running. */ pidfile_remove(pfh); return (SA_OK); } if (errno != EEXIST) { /* Cannot open pidfile for some reason. */ return (SA_SYSTEM_ERR); } /* We have mountd(8) PID in mountdpid variable. */ kill(mountdpid, SIGHUP); return (SA_OK); } static const sa_share_ops_t nfs_shareops = { .enable_share = nfs_enable_share, .disable_share = nfs_disable_share, .is_shared = nfs_is_shared, .validate_shareopts = nfs_validate_shareopts, .update_shareopts = nfs_update_shareopts, .clear_shareopts = nfs_clear_shareopts, .commit_shares = nfs_commit_shares, }; /* * Initializes the NFS functionality of libshare. */ void libshare_nfs_init(void) { nfs_fstype = register_fstype("nfs", &nfs_shareops); }