1 files changed, 587 insertions, 0 deletions

diff --git a/sys/contrib/openzfs/lib/libshare/os/linux/nfs.c b/sys/contrib/openzfs/lib/libshare/os/linux/nfs.c
new file mode 100644
index 000000000000..6a9bb3788523
--- /dev/null
+++ b/sys/contrib/openzfs/lib/libshare/os/linux/nfs.c
@@ -0,0 +1,587 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011 Gunnar Beutner
+ * Copyright (c) 2012 Cyril Plisko. All rights reserved.
+ * Copyright (c) 2019, 2022 by Delphix. All rights reserved.
+ */
+
+#include <dirent.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <libzfs.h>
+#include <libshare.h>
+#include "libshare_impl.h"
+#include "nfs.h"
+
+#define	ZFS_EXPORTS_DIR		"/etc/exports.d"
+#define	ZFS_EXPORTS_FILE	ZFS_EXPORTS_DIR"/zfs.exports"
+#define	ZFS_EXPORTS_LOCK	ZFS_EXPORTS_FILE".lock"
+
+
+static boolean_t nfs_available(void);
+static boolean_t exports_available(void);
+
+typedef int (*nfs_shareopt_callback_t)(const char *opt, const char *value,
+    void *cookie);
+
+typedef int (*nfs_host_callback_t)(FILE *tmpfile, const char *sharepath,
+    const char *host, const char *security, const char *access, void *cookie);
+
+/*
+ * Invokes the specified callback function for each Solaris share option
+ * listed in the specified string.
+ */
+static int
+foreach_nfs_shareopt(const char *shareopts,
+    nfs_shareopt_callback_t callback, void *cookie)
+{
+	char *shareopts_dup, *opt, *cur, *value;
+	int was_nul, error;
+
+	if (shareopts == NULL)
+		return (SA_OK);
+
+	if (strcmp(shareopts, "on") == 0)
+		shareopts = "rw,crossmnt";
+
+	shareopts_dup = strdup(shareopts);
+
+
+	if (shareopts_dup == NULL)
+		return (SA_NO_MEMORY);
+
+	opt = shareopts_dup;
+	was_nul = 0;
+
+	while (1) {
+		cur = opt;
+
+		while (*cur != ',' && *cur != '\0')
+			cur++;
+
+		if (*cur == '\0')
+			was_nul = 1;
+
+		*cur = '\0';
+
+		if (cur > opt) {
+			value = strchr(opt, '=');
+
+			if (value != NULL) {
+				*value = '\0';
+				value++;
+			}
+
+			error = callback(opt, value, cookie);
+
+			if (error != SA_OK) {
+				free(shareopts_dup);
+				return (error);
+			}
+		}
+
+		opt = cur + 1;
+
+		if (was_nul)
+			break;
+	}
+
+	free(shareopts_dup);
+
+	return (SA_OK);
+}
+
+typedef struct nfs_host_cookie_s {
+	nfs_host_callback_t callback;
+	const char *sharepath;
+	void *cookie;
+	FILE *tmpfile;
+	const char *security;
+} nfs_host_cookie_t;
+
+/*
+ * Helper function for foreach_nfs_host. This function checks whether the
+ * current share option is a host specification and invokes a callback
+ * function with information about the host.
+ */
+static int
+foreach_nfs_host_cb(const char *opt, const char *value, void *pcookie)
+{
+	int error;
+	const char *access;
+	char *host_dup, *host, *next, *v6Literal;
+	nfs_host_cookie_t *udata = (nfs_host_cookie_t *)pcookie;
+	int cidr_len;
+
+#ifdef DEBUG
+	fprintf(stderr, "foreach_nfs_host_cb: key=%s, value=%s\n", opt, value);
+#endif
+
+	if (strcmp(opt, "sec") == 0)
+		udata->security = value;
+
+	if (strcmp(opt, "rw") == 0 || strcmp(opt, "ro") == 0) {
+		if (value == NULL)
+			value = "*";
+
+		access = opt;
+
+		host_dup = strdup(value);
+
+		if (host_dup == NULL)
+			return (SA_NO_MEMORY);
+
+		host = host_dup;
+
+		do {
+			if (*host == '[') {
+				host++;
+				v6Literal = strchr(host, ']');
+				if (v6Literal == NULL) {
+					free(host_dup);
+					return (SA_SYNTAX_ERR);
+				}
+				if (v6Literal[1] == '\0') {
+					*v6Literal = '\0';
+					next = NULL;
+				} else if (v6Literal[1] == '/') {
+					next = strchr(v6Literal + 2, ':');
+					if (next == NULL) {
+						cidr_len =
+						    strlen(v6Literal + 1);
+						memmove(v6Literal,
+						    v6Literal + 1,
+						    cidr_len);
+						v6Literal[cidr_len] = '\0';
+					} else {
+						cidr_len = next - v6Literal - 1;
+						memmove(v6Literal,
+						    v6Literal + 1,
+						    cidr_len);
+						v6Literal[cidr_len] = '\0';
+						next++;
+					}
+				} else if (v6Literal[1] == ':') {
+					*v6Literal = '\0';
+					next = v6Literal + 2;
+				} else {
+					free(host_dup);
+					return (SA_SYNTAX_ERR);
+				}
+			} else {
+				next = strchr(host, ':');
+				if (next != NULL) {
+					*next = '\0';
+					next++;
+				}
+			}
+
+			error = udata->callback(udata->tmpfile,
+			    udata->sharepath, host, udata->security,
+			    access, udata->cookie);
+
+			if (error != SA_OK) {
+				free(host_dup);
+
+				return (error);
+			}
+
+			host = next;
+		} while (host != NULL);
+
+		free(host_dup);
+	}
+
+	return (SA_OK);
+}
+
+/*
+ * Invokes a callback function for all NFS hosts that are set for a share.
+ */
+static int
+foreach_nfs_host(sa_share_impl_t impl_share, FILE *tmpfile,
+    nfs_host_callback_t callback, void *cookie)
+{
+	nfs_host_cookie_t udata;
+
+	udata.callback = callback;
+	udata.sharepath = impl_share->sa_mountpoint;
+	udata.cookie = cookie;
+	udata.tmpfile = tmpfile;
+	udata.security = "sys";
+
+	return (foreach_nfs_shareopt(impl_share->sa_shareopts,
+	    foreach_nfs_host_cb, &udata));
+}
+
+/*
+ * Converts a Solaris NFS host specification to its Linux equivalent.
+ */
+static const char *
+get_linux_hostspec(const char *solaris_hostspec)
+{
+	/*
+	 * For now we just support CIDR masks (e.g. @192.168.0.0/16) and host
+	 * wildcards (e.g. *.example.org).
+	 */
+	if (solaris_hostspec[0] == '@') {
+		/*
+		 * Solaris host specifier, e.g. @192.168.0.0/16; we just need
+		 * to skip the @ in this case
+		 */
+		return (solaris_hostspec + 1);
+	} else {
+		return (solaris_hostspec);
+	}
+}
+
+/*
+ * Adds a Linux share option to an array of NFS options.
+ */
+static int
+add_linux_shareopt(char **plinux_opts, const char *key, const char *value)
+{
+	size_t len = 0;
+	char *new_linux_opts;
+
+	if (*plinux_opts != NULL)
+		len = strlen(*plinux_opts);
+
+	new_linux_opts = realloc(*plinux_opts, len + 1 + strlen(key) +
+	    (value ? 1 + strlen(value) : 0) + 1);
+
+	if (new_linux_opts == NULL)
+		return (SA_NO_MEMORY);
+
+	new_linux_opts[len] = '\0';
+
+	if (len > 0)
+		strcat(new_linux_opts, ",");
+
+	strcat(new_linux_opts, key);
+
+	if (value != NULL) {
+		strcat(new_linux_opts, "=");
+		strcat(new_linux_opts, value);
+	}
+
+	*plinux_opts = new_linux_opts;
+
+	return (SA_OK);
+}
+
+static int string_cmp(const void *lhs, const void *rhs) {
+	const char *const *l = lhs, *const *r = rhs;
+	return (strcmp(*l, *r));
+}
+
+/*
+ * Validates and converts a single Solaris share option to its Linux
+ * equivalent.
+ */
+static int
+get_linux_shareopts_cb(const char *key, const char *value, void *cookie)
+{
+	/* This list must remain sorted, since we bsearch() it */
+	static const char *const valid_keys[] = { "all_squash", "anongid",
+	    "anonuid", "async", "auth_nlm", "crossmnt", "fsid", "fsuid", "hide",
+	    "insecure", "insecure_locks", "mountpoint", "mp", "no_acl",
+	    "no_all_squash", "no_auth_nlm", "no_root_squash",
+	    "no_subtree_check", "no_wdelay", "nohide", "refer", "replicas",
+	    "root_squash", "secure", "secure_locks", "subtree_check", "sync",
+	    "wdelay" };
+
+	char **plinux_opts = (char **)cookie;
+	char *host, *val_dup, *literal, *next;
+
+	if (strcmp(key, "sec") == 0)
+		return (SA_OK);
+
+	if (strcmp(key, "ro") == 0 || strcmp(key, "rw") == 0) {
+		if (value == NULL || strlen(value) == 0)
+			return (SA_OK);
+		val_dup = strdup(value);
+		host = val_dup;
+		if (host == NULL)
+			return (SA_NO_MEMORY);
+		do {
+			if (*host == '[') {
+				host++;
+				literal = strchr(host, ']');
+				if (literal == NULL) {
+					free(val_dup);
+					return (SA_SYNTAX_ERR);
+				}
+				if (literal[1] == '\0')
+					next = NULL;
+				else if (literal[1] == '/') {
+					next = strchr(literal + 2, ':');
+					if (next != NULL)
+						++next;
+				} else if (literal[1] == ':')
+					next = literal + 2;
+				else {
+					free(val_dup);
+					return (SA_SYNTAX_ERR);
+				}
+			} else {
+				next = strchr(host, ':');
+				if (next != NULL)
+					++next;
+			}
+			host = next;
+		} while (host != NULL);
+		free(val_dup);
+		return (SA_OK);
+	}
+
+	if (strcmp(key, "anon") == 0)
+		key = "anonuid";
+
+	if (strcmp(key, "root_mapping") == 0) {
+		(void) add_linux_shareopt(plinux_opts, "root_squash", NULL);
+		key = "anonuid";
+	}
+
+	if (strcmp(key, "nosub") == 0)
+		key = "subtree_check";
+
+	if (bsearch(&key, valid_keys, ARRAY_SIZE(valid_keys),
+	    sizeof (*valid_keys), string_cmp) == NULL)
+		return (SA_SYNTAX_ERR);
+
+	(void) add_linux_shareopt(plinux_opts, key, value);
+
+	return (SA_OK);
+}
+
+/*
+ * Takes a string containing Solaris share options (e.g. "sync,no_acl") and
+ * converts them to a NULL-terminated array of Linux NFS options.
+ */
+static int
+get_linux_shareopts(const char *shareopts, char **plinux_opts)
+{
+	int error;
+
+	assert(plinux_opts != NULL);
+
+	*plinux_opts = NULL;
+
+	/* no_subtree_check - Default as of nfs-utils v1.1.0 */
+	(void) add_linux_shareopt(plinux_opts, "no_subtree_check", NULL);
+
+	/* mountpoint - Restrict exports to ZFS mountpoints */
+	(void) add_linux_shareopt(plinux_opts, "mountpoint", NULL);
+
+	error = foreach_nfs_shareopt(shareopts, get_linux_shareopts_cb,
+	    plinux_opts);
+
+	if (error != SA_OK) {
+		free(*plinux_opts);
+		*plinux_opts = NULL;
+	}
+
+	return (error);
+}
+
+/*
+ * This function populates an entry into /etc/exports.d/zfs.exports.
+ * This file is consumed by the linux nfs server so that zfs shares are
+ * automatically exported upon boot or whenever the nfs server restarts.
+ */
+static int
+nfs_add_entry(FILE *tmpfile, const char *sharepath,
+    const char *host, const char *security, const char *access_opts,
+    void *pcookie)
+{
+	const char *linux_opts = (const char *)pcookie;
+
+	if (linux_opts == NULL)
+		linux_opts = "";
+
+	boolean_t need_free;
+	char *mp;
+	int rc = nfs_escape_mountpoint(sharepath, &mp, &need_free);
+	if (rc != SA_OK)
+		return (rc);
+	if (fprintf(tmpfile, "%s %s(sec=%s,%s,%s)\n", mp,
+	    get_linux_hostspec(host), security, access_opts,
+	    linux_opts) < 0) {
+		fprintf(stderr, "failed to write to temporary file\n");
+		rc = SA_SYSTEM_ERR;
+	}
+
+	if (need_free)
+		free(mp);
+	return (rc);
+}
+
+/*
+ * Enables NFS sharing for the specified share.
+ */
+static int
+nfs_enable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
+{
+	char *linux_opts = NULL;
+	int error = get_linux_shareopts(impl_share->sa_shareopts, &linux_opts);
+	if (error != SA_OK)
+		return (error);
+
+	error = foreach_nfs_host(impl_share, tmpfile, nfs_add_entry,
+	    linux_opts);
+	free(linux_opts);
+	return (error);
+}
+
+static int
+nfs_enable_share(sa_share_impl_t impl_share)
+{
+	if (!nfs_available())
+		return (SA_SYSTEM_ERR);
+
+	return (nfs_toggle_share(
+	    ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, ZFS_EXPORTS_DIR, impl_share,
+	    nfs_enable_share_impl));
+}
+
+/*
+ * Disables NFS sharing for the specified share.
+ */
+static int
+nfs_disable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
+{
+	(void) impl_share, (void) tmpfile;
+	return (SA_OK);
+}
+
+static int
+nfs_disable_share(sa_share_impl_t impl_share)
+{
+	if (!nfs_available())
+		return (SA_OK);
+
+	return (nfs_toggle_share(
+	    ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, ZFS_EXPORTS_DIR, impl_share,
+	    nfs_disable_share_impl));
+}
+
+static boolean_t
+nfs_is_shared(sa_share_impl_t impl_share)
+{
+	if (!nfs_available())
+		return (SA_SYSTEM_ERR);
+
+	return (nfs_is_shared_impl(ZFS_EXPORTS_FILE, impl_share));
+}
+
+/*
+ * Checks whether the specified NFS share options are syntactically correct.
+ */
+static int
+nfs_validate_shareopts(const char *shareopts)
+{
+	char *linux_opts = NULL;
+
+	if (strlen(shareopts) == 0)
+		return (SA_SYNTAX_ERR);
+
+	int error = get_linux_shareopts(shareopts, &linux_opts);
+	if (error != SA_OK)
+		return (error);
+
+	free(linux_opts);
+	return (SA_OK);
+}
+
+static int
+nfs_commit_shares(void)
+{
+	if (!nfs_available())
+		return (SA_SYSTEM_ERR);
+
+	char *argv[] = {
+	    (char *)"/usr/sbin/exportfs",
+	    (char *)"-ra",
+	    NULL
+	};
+
+	return (libzfs_run_process(argv[0], argv, 0));
+}
+
+static void
+nfs_truncate_shares(void)
+{
+	if (!exports_available())
+		return;
+	nfs_reset_shares(ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE);
+}
+
+const sa_fstype_t libshare_nfs_type = {
+	.enable_share = nfs_enable_share,
+	.disable_share = nfs_disable_share,
+	.is_shared = nfs_is_shared,
+
+	.validate_shareopts = nfs_validate_shareopts,
+	.commit_shares = nfs_commit_shares,
+	.truncate_shares = nfs_truncate_shares,
+};
+
+static boolean_t
+nfs_available(void)
+{
+	static int avail;
+
+	if (!avail) {
+		if (access("/usr/sbin/exportfs", F_OK) != 0)
+			avail = -1;
+		else
+			avail = 1;
+	}
+
+	return (avail == 1);
+}
+
+static boolean_t
+exports_available(void)
+{
+	static int avail;
+
+	if (!avail) {
+		if (access(ZFS_EXPORTS_DIR, F_OK) != 0)
+			avail = -1;
+		else
+			avail = 1;
+	}
+
+	return (avail == 1);
+}