1 files changed, 407 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/lib/libshare/os/linux/smb.c b/sys/contrib/openzfs/lib/libshare/os/linux/smb.c
new file mode 100644
index 000000000000..40996ecc8f89
--- /dev/null
+++ b/sys/contrib/openzfs/lib/libshare/os/linux/smb.c
@@ -0,0 +1,407 @@
+// 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) 2011,2012 Turbo Fredriksson <turbo@bayour.com>, based on nfs.c
+ *                         by Gunnar Beutner
+ * Copyright (c) 2019, 2020 by Delphix. All rights reserved.
+ *
+ * This is an addition to the zfs device driver to add, modify and remove SMB
+ * shares using the 'net share' command that comes with Samba.
+ *
+ * TESTING
+ * Make sure that samba listens to 'localhost' (127.0.0.1) and that the options
+ * 'usershare max shares' and 'usershare owner only' have been reviewed/set
+ * accordingly (see zfs(8) for information).
+ *
+ * Once configuration in samba have been done, test that this
+ * works with the following three commands (in this case, my ZFS
+ * filesystem is called 'share/Test1'):
+ *
+ *	(root)# net -U root -S 127.0.0.1 usershare add Test1 /share/Test1 \
+ *		"Comment: /share/Test1" "Everyone:F"
+ *	(root)# net usershare list | grep -i test
+ *	(root)# net -U root -S 127.0.0.1 usershare delete Test1
+ *
+ * The first command will create a user share that gives everyone full access.
+ * To limit the access below that, use normal UNIX commands (chmod, chown etc).
+ */
+
+#include <time.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <libzfs.h>
+#include <libshare.h>
+#include "libshare_impl.h"
+#include "smb.h"
+
+static boolean_t smb_available(void);
+
+static smb_share_t *smb_shares;
+static int smb_disable_share(sa_share_impl_t impl_share);
+static boolean_t smb_is_share_active(sa_share_impl_t impl_share);
+
+/*
+ * Retrieve the list of SMB shares.
+ */
+static int
+smb_retrieve_shares(void)
+{
+	int rc = SA_OK;
+	char file_path[PATH_MAX], line[512], *token, *key, *value;
+	char *dup_value = NULL, *path = NULL, *comment = NULL, *name = NULL;
+	char *guest_ok = NULL;
+	DIR *shares_dir;
+	FILE *share_file_fp = NULL;
+	struct dirent *directory;
+	struct stat eStat;
+	smb_share_t *shares, *new_shares = NULL;
+
+	/* opendir(), stat() */
+	shares_dir = opendir(SHARE_DIR);
+	if (shares_dir == NULL)
+		return (SA_SYSTEM_ERR);
+
+	/* Go through the directory, looking for shares */
+	while ((directory = readdir(shares_dir))) {
+		int fd;
+
+		if (directory->d_name[0] == '.')
+			continue;
+
+		snprintf(file_path, sizeof (file_path),
+		    "%s/%s", SHARE_DIR, directory->d_name);
+
+		if ((fd = open(file_path, O_RDONLY | O_CLOEXEC)) == -1) {
+			rc = SA_SYSTEM_ERR;
+			goto out;
+		}
+
+		if (fstat(fd, &eStat) == -1) {
+			close(fd);
+			rc = SA_SYSTEM_ERR;
+			goto out;
+		}
+
+		if (!S_ISREG(eStat.st_mode)) {
+			close(fd);
+			continue;
+		}
+
+		if ((share_file_fp = fdopen(fd, "r")) == NULL) {
+			close(fd);
+			rc = SA_SYSTEM_ERR;
+			goto out;
+		}
+
+		name = strdup(directory->d_name);
+		if (name == NULL) {
+			rc = SA_NO_MEMORY;
+			goto out;
+		}
+
+		while (fgets(line, sizeof (line), share_file_fp)) {
+			if (line[0] == '#')
+				continue;
+
+			/* Trim trailing new-line character(s). */
+			while (line[strlen(line) - 1] == '\r' ||
+			    line[strlen(line) - 1] == '\n')
+				line[strlen(line) - 1] = '\0';
+
+			/* Split the line in two, separated by '=' */
+			token = strchr(line, '=');
+			if (token == NULL)
+				continue;
+
+			key = line;
+			value = token + 1;
+			*token = '\0';
+
+			dup_value = strdup(value);
+			if (dup_value == NULL) {
+				rc = SA_NO_MEMORY;
+				goto out;
+			}
+
+			if (strcmp(key, "path") == 0) {
+				free(path);
+				path = dup_value;
+			} else if (strcmp(key, "comment") == 0) {
+				free(comment);
+				comment = dup_value;
+			} else if (strcmp(key, "guest_ok") == 0) {
+				free(guest_ok);
+				guest_ok = dup_value;
+			} else
+				free(dup_value);
+
+			dup_value = NULL;
+
+			if (path == NULL || comment == NULL || guest_ok == NULL)
+				continue; /* Incomplete share definition */
+			else {
+				shares = (smb_share_t *)
+				    malloc(sizeof (smb_share_t));
+				if (shares == NULL) {
+					rc = SA_NO_MEMORY;
+					goto out;
+				}
+
+				(void) strlcpy(shares->name, name,
+				    sizeof (shares->name));
+
+				(void) strlcpy(shares->path, path,
+				    sizeof (shares->path));
+
+				(void) strlcpy(shares->comment, comment,
+				    sizeof (shares->comment));
+
+				shares->guest_ok = atoi(guest_ok);
+
+				shares->next = new_shares;
+				new_shares = shares;
+
+				free(path);
+				free(comment);
+				free(guest_ok);
+
+				path = NULL;
+				comment = NULL;
+				guest_ok = NULL;
+			}
+		}
+
+out:
+		if (share_file_fp != NULL) {
+			fclose(share_file_fp);
+			share_file_fp = NULL;
+		}
+
+		free(name);
+		free(path);
+		free(comment);
+		free(guest_ok);
+
+		name = NULL;
+		path = NULL;
+		comment = NULL;
+		guest_ok = NULL;
+	}
+	closedir(shares_dir);
+
+	smb_shares = new_shares;
+
+	return (rc);
+}
+
+/*
+ * Used internally by smb_enable_share to enable sharing for a single host.
+ */
+static int
+smb_enable_share_one(const char *sharename, const char *sharepath)
+{
+	char name[SMB_NAME_MAX], comment[SMB_COMMENT_MAX];
+
+	/* Support ZFS share name regexp '[[:alnum:]_-.: ]' */
+	strlcpy(name, sharename, sizeof (name));
+	for (char *itr = name; *itr != '\0'; ++itr)
+		switch (*itr) {
+		case '/':
+		case '-':
+		case ':':
+		case ' ':
+			*itr = '_';
+		}
+
+	/*
+	 * CMD: net -S NET_CMD_ARG_HOST usershare add Test1 /share/Test1 \
+	 *      "Comment" "Everyone:F"
+	 */
+	snprintf(comment, sizeof (comment), "Comment: %s", sharepath);
+
+	char *argv[] = {
+		(char *)NET_CMD_PATH,
+		(char *)"-S",
+		(char *)NET_CMD_ARG_HOST,
+		(char *)"usershare",
+		(char *)"add",
+		name,
+		(char *)sharepath,
+		comment,
+		(char *)"Everyone:F",
+		NULL,
+	};
+
+	if (libzfs_run_process(argv[0], argv, 0) != 0)
+		return (SA_SYSTEM_ERR);
+
+	/* Reload the share file */
+	(void) smb_retrieve_shares();
+
+	return (SA_OK);
+}
+
+/*
+ * Enables SMB sharing for the specified share.
+ */
+static int
+smb_enable_share(sa_share_impl_t impl_share)
+{
+	if (!smb_available())
+		return (SA_SYSTEM_ERR);
+
+	if (smb_is_share_active(impl_share))
+		smb_disable_share(impl_share);
+
+	if (impl_share->sa_shareopts == NULL) /* on/off */
+		return (SA_SYSTEM_ERR);
+
+	if (strcmp(impl_share->sa_shareopts, "off") == 0)
+		return (SA_OK);
+
+	/* Magic: Enable (i.e., 'create new') share */
+	return (smb_enable_share_one(impl_share->sa_zfsname,
+	    impl_share->sa_mountpoint));
+}
+
+/*
+ * Used internally by smb_disable_share to disable sharing for a single host.
+ */
+static int
+smb_disable_share_one(const char *sharename)
+{
+	/* CMD: net -S NET_CMD_ARG_HOST usershare delete Test1 */
+	char *argv[] = {
+		(char *)NET_CMD_PATH,
+		(char *)"-S",
+		(char *)NET_CMD_ARG_HOST,
+		(char *)"usershare",
+		(char *)"delete",
+		(char *)sharename,
+		NULL,
+	};
+
+	if (libzfs_run_process(argv[0], argv, 0) != 0)
+		return (SA_SYSTEM_ERR);
+	else
+		return (SA_OK);
+}
+
+/*
+ * Disables SMB sharing for the specified share.
+ */
+static int
+smb_disable_share(sa_share_impl_t impl_share)
+{
+	if (!smb_available()) {
+		/*
+		 * The share can't possibly be active, so nothing
+		 * needs to be done to disable it.
+		 */
+		return (SA_OK);
+	}
+
+	for (const smb_share_t *i = smb_shares; i != NULL; i = i->next)
+		if (strcmp(impl_share->sa_mountpoint, i->path) == 0)
+			return (smb_disable_share_one(i->name));
+
+	return (SA_OK);
+}
+
+/*
+ * Checks whether the specified SMB share options are syntactically correct.
+ */
+static int
+smb_validate_shareopts(const char *shareopts)
+{
+	/* TODO: Accept 'name' and sec/acl (?) */
+	if ((strcmp(shareopts, "off") == 0) || (strcmp(shareopts, "on") == 0))
+		return (SA_OK);
+
+	return (SA_SYNTAX_ERR);
+}
+
+/*
+ * Checks whether a share is currently active.
+ */
+static boolean_t
+smb_is_share_active(sa_share_impl_t impl_share)
+{
+	if (!smb_available())
+		return (B_FALSE);
+
+	/* Retrieve the list of (possible) active shares */
+	smb_retrieve_shares();
+
+	for (const smb_share_t *i = smb_shares; i != NULL; i = i->next)
+		if (strcmp(impl_share->sa_mountpoint, i->path) == 0)
+			return (B_TRUE);
+
+	return (B_FALSE);
+}
+
+static int
+smb_update_shares(void)
+{
+	/* Not implemented */
+	return (0);
+}
+
+const sa_fstype_t libshare_smb_type = {
+	.enable_share = smb_enable_share,
+	.disable_share = smb_disable_share,
+	.is_shared = smb_is_share_active,
+
+	.validate_shareopts = smb_validate_shareopts,
+	.commit_shares = smb_update_shares,
+};
+
+/*
+ * Provides a convenient wrapper for determining SMB availability
+ */
+static boolean_t
+smb_available(void)
+{
+	static int avail;
+
+	if (!avail) {
+		struct stat statbuf;
+
+		if (access(NET_CMD_PATH, F_OK) != 0 ||
+		    lstat(SHARE_DIR, &statbuf) != 0 ||
+		    !S_ISDIR(statbuf.st_mode))
+			avail = -1;
+		else
+			avail = 1;
+	}
+
+	return (avail == 1);
+}