/* $NetBSD: fsshare.c,v 1.4 2019/01/27 02:08:34 pgoyette Exp $ */ /*- * 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. */ #include /* __FBSDID("$FreeBSD: head/cddl/compat/opensolaris/misc/fsshare.c 299342 2016-05-10 07:50:57Z bapt $"); */ __RCSID("$NetBSD: fsshare.c,v 1.4 2019/01/27 02:08:34 pgoyette Exp $"); #include #include #include #include #include #include /* _PATH_MOUNTDPID */ #include #include #include #include #include #define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n" #define OPTSSIZE 1024 #define MAXLINESIZE (PATH_MAX + OPTSSIZE) static void restart_mountd(void) { int pid; FILE *pfh; pfh = fopen(_PATH_MOUNTDPID, "r"); if (pfh == NULL) return; fscanf(pfh, "%d", &pid); fclose(pfh); kill((pid_t)pid, SIGHUP); } /* * Read one line from a file. Skip comments, empty lines and a line with a * mountpoint specified in the 'skip' argument. */ static char * zgetline(FILE *fd, const char *skip) { static char line[MAXLINESIZE]; size_t len, skiplen; 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); } /* * Function translate options to a format acceptable by exports(5), eg. * * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org 69.147.83.54 * * Accepted input formats: * * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,freefall.freebsd.org * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 freefall.freebsd.org * -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,freefall.freebsd.org * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org * * Recognized keywords: * * ro, maproot, mapall, mask, network, alldirs, public, webnfs, index, quiet * */ static const char *known_opts[] = { "ro", "maproot", "mapall", "mask", "network", "alldirs", "public", "webnfs", "index", "quiet", NULL }; static char * translate_opts(const char *shareopts) { 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 int fsshare_main(const char *file, const char *mountpoint, const char *shareopts, int share) { char tmpfile[PATH_MAX]; char *line; FILE *newfd, *oldfd; int fd, error; newfd = oldfd = NULL; error = 0; /* * Create temporary file in the same directory, so we can atomically * rename it. */ if (strlcpy(tmpfile, file, sizeof(tmpfile)) >= sizeof(tmpfile)) return (ENAMETOOLONG); if (strlcat(tmpfile, ".XXXXXXXX", sizeof(tmpfile)) >= sizeof(tmpfile)) return (ENAMETOOLONG); fd = mkstemp(tmpfile); if (fd == -1) return (errno); /* * File name is random, so we don't really need file lock now, but it * will be needed after rename(2). */ error = flock(fd, LOCK_EX); assert(error == 0 || (error == -1 && errno == EOPNOTSUPP)); newfd = fdopen(fd, "r+"); assert(newfd != NULL); /* Open old exports file. */ oldfd = fopen(file, "r"); if (oldfd == NULL) { if (share) { if (errno != ENOENT) { error = errno; goto out; } } else { /* If there is no exports file, ignore the error. */ if (errno == ENOENT) errno = 0; error = errno; goto out; } } else { error = flock(fileno(oldfd), LOCK_EX); assert(error == 0 || (error == -1 && errno == EOPNOTSUPP)); error = 0; } /* Place big, fat warning at the begining of the file. */ fprintf(newfd, "%s", FILE_HEADER); while (oldfd != NULL && (line = zgetline(oldfd, mountpoint)) != NULL) fprintf(newfd, "%s\n", line); if (oldfd != NULL && ferror(oldfd) != 0) { error = ferror(oldfd); goto out; } if (ferror(newfd) != 0) { error = ferror(newfd); goto out; } if (share) { fprintf(newfd, "%s\t%s\n", mountpoint, translate_opts(shareopts)); } out: if (error != 0) unlink(tmpfile); else { if (rename(tmpfile, file) == -1) { error = errno; unlink(tmpfile); } else { /* * Send SIGHUP to mountd, but unlock exports file later. */ restart_mountd(); } } if (oldfd != NULL) { flock(fileno(oldfd), LOCK_UN); fclose(oldfd); } if (newfd != NULL) { flock(fileno(newfd), LOCK_UN); fclose(newfd); } return (error); } /* * Add the given mountpoint to the given exports file. */ int fsshare(const char *file, const char *mountpoint, const char *shareopts) { return (fsshare_main(file, mountpoint, shareopts, 1)); } /* * Remove the given mountpoint from the given exports file. */ int fsunshare(const char *file, const char *mountpoint) { return (fsshare_main(file, mountpoint, NULL, 0)); }