Implemented sharing datasets via NFS using libshare.

The sharenfs and sharesmb properties depend on the libshare library
to export datasets via NFS and SMB. This commit implements the base
libshare functionality as well as support for managing NFS shares.

Signed-off-by: Brian Behlendorf <[email protected]>

1 files changed, 705 insertions, 0 deletions

diff --git a/lib/libshare/nfs.c b/lib/libshare/nfs.c
new file mode 100644
index 000000000..60edaa2c3
--- /dev/null
+++ b/lib/libshare/nfs.c
@@ -0,0 +1,705 @@
+/*
+ * 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 http://www.opensolaris.org/os/licensing.
+ * 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
+ */
+
+#include <stdio.h>
+#include <strings.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <libzfs.h>
+#include <libshare.h>
+#include "libshare_impl.h"
+
+static sa_fstype_t *nfs_fstype;
+static boolean_t nfs_available;
+
+typedef int (*nfs_shareopt_callback_t)(const char *opt, const char *value,
+    void *cookie);
+
+typedef int (*nfs_host_callback_t)(const char *sharepath, const char *host,
+    const char *security, const char *access, void *cookie);
+
+static int
+foreach_nfs_shareopt(const char *shareopts,
+    nfs_shareopt_callback_t callback, void *cookie)
+{
+	char *shareopts_dup, *opt, *cur, *value;
+	int was_nul, rc;
+
+	if (shareopts == NULL)
+		return SA_OK;
+
+	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++;
+			}
+
+			rc = callback(opt, value, cookie);
+
+			if (rc != SA_OK) {
+				free(shareopts_dup);
+				return rc;
+			}
+		}
+
+		opt = cur + 1;
+
+		if (was_nul)
+			break;
+	}
+
+	free(shareopts_dup);
+
+	return 0;
+}
+
+typedef struct nfs_host_cookie_s {
+	nfs_host_callback_t callback;
+	const char *sharepath;
+	void *cookie;
+	const char *security;
+} nfs_host_cookie_t;
+
+static int
+foreach_nfs_host_cb(const char *opt, const char *value, void *pcookie)
+{
+	int rc;
+	const char *access;
+	char *host_dup, *host, *next;
+	nfs_host_cookie_t *udata = (nfs_host_cookie_t *)pcookie;
+
+#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 {
+			next = strchr(host, ':');
+			if (next != NULL) {
+				*next = '\0';
+				next++;
+			}
+
+			rc = udata->callback(udata->sharepath, host,
+			    udata->security, access, udata->cookie);
+
+			if (rc != SA_OK) {
+				free(host_dup);
+
+				return rc;
+			}
+
+			host = next;
+		} while (host != NULL);
+
+		free(host_dup);
+	}
+
+	return SA_OK;
+}
+
+static int
+foreach_nfs_host(sa_share_impl_t impl_share, nfs_host_callback_t callback,
+    void *cookie)
+{
+	nfs_host_cookie_t udata;
+	char *shareopts;
+
+	udata.callback = callback;
+	udata.sharepath = impl_share->sharepath;
+	udata.cookie = cookie;
+	udata.security = "sys";
+
+	shareopts = FSINFO(impl_share, nfs_fstype)->shareopts;
+
+	return foreach_nfs_shareopt(shareopts, foreach_nfs_host_cb,
+	    &udata);
+}
+
+static int
+get_linux_hostspec(const char *solaris_hostspec, char **plinux_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
+		 */
+		*plinux_hostspec = strdup(solaris_hostspec + 1);
+	} else {
+		*plinux_hostspec = strdup(solaris_hostspec);
+	}
+
+	if (*plinux_hostspec == NULL) {
+		return SA_NO_MEMORY;
+	}
+
+	return SA_OK;
+}
+
+static int
+nfs_enable_share_one(const char *sharepath, const char *host,
+    const char *security, const char *access, void *pcookie)
+{
+	pid_t pid;
+	int rc, status;
+	char *linuxhost, *hostpath, *opts;
+	const char *linux_opts = (const char *)pcookie;
+
+	pid = fork();
+
+	if (pid < 0)
+		return SA_SYSTEM_ERR;
+
+	if (pid > 0) {
+		while ((rc = waitpid(pid, &status, 0)) <= 0 && errno == EINTR)
+			; /* empty loop body */
+
+		if (rc <= 0)
+			return SA_SYSTEM_ERR;
+
+		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+			return SA_CONFIG_ERR;
+
+		return SA_OK;
+	}
+
+	/* child */
+
+	/* exportfs -i -o sec=XX,rX,<opts> <host>:<sharepath> */
+
+	rc = get_linux_hostspec(host, &linuxhost);
+
+	if (rc < 0)
+		exit(1);
+
+	hostpath = malloc(strlen(linuxhost) + 1 + strlen(sharepath) + 1);
+
+	if (hostpath == NULL) {
+		free(linuxhost);
+
+		exit(1);
+	}
+
+	sprintf(hostpath, "%s:%s", linuxhost, sharepath);
+
+	free(linuxhost);
+
+	if (linux_opts == NULL)
+		linux_opts = "";
+
+	opts = malloc(4 + strlen(security) + 4 + strlen(linux_opts) + 1);
+
+	if (opts == NULL)
+		exit(1);
+
+	sprintf(opts, "sec=%s,%s,%s", security, access, linux_opts);
+
+#ifdef DEBUG
+	fprintf(stderr, "sharing %s with opts %s\n", hostpath, opts);
+#endif
+
+	rc = execlp("/usr/sbin/exportfs", "exportfs", "-i", \
+	    "-o", opts, hostpath, NULL);
+
+	if (rc < 0) {
+		free(hostpath);
+		free(opts);
+		exit(1);
+	}
+
+	exit(0);
+}
+
+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
+get_linux_shareopts_cb(const char *key, const char *value, void *cookie)
+{
+	char **plinux_opts = (char **)cookie;
+
+	/* host-specific options, these are taken care of elsewhere */
+	if (strcmp(key, "ro") == 0 || strcmp(key, "rw") == 0 ||
+	    strcmp(key, "sec") == 0)
+		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 (strcmp(key, "insecure") != 0 && strcmp(key, "secure") != 0 &&
+	    strcmp(key, "async") != 0 && strcmp(key, "sync") != 0 &&
+	    strcmp(key, "no_wdelay") != 0 && strcmp(key, "wdelay") != 0 &&
+	    strcmp(key, "nohide") != 0 && strcmp(key, "hide") != 0 &&
+	    strcmp(key, "crossmnt") != 0 &&
+	    strcmp(key, "no_subtree_check") != 0 &&
+	    strcmp(key, "subtree_check") != 0 &&
+	    strcmp(key, "insecure_locks") != 0 &&
+	    strcmp(key, "secure_locks") != 0 &&
+	    strcmp(key, "no_auth_nlm") != 0 && strcmp(key, "auth_nlm") != 0 &&
+	    strcmp(key, "no_acl") != 0 && strcmp(key, "mountpoint") != 0 &&
+	    strcmp(key, "mp") != 0 && strcmp(key, "fsuid") != 0 &&
+	    strcmp(key, "refer") != 0 && strcmp(key, "replicas") != 0 &&
+	    strcmp(key, "root_squash") != 0 &&
+	    strcmp(key, "no_root_squash") != 0 &&
+	    strcmp(key, "all_squash") != 0 &&
+	    strcmp(key, "no_all_squash") != 0 &&
+	    strcmp(key, "anonuid") != 0 && strcmp(key, "anongid") != 0) {
+		return SA_SYNTAX_ERR;
+	}
+
+	(void) add_linux_shareopt(plinux_opts, key, value);
+
+	return SA_OK;
+}
+
+static int
+get_linux_shareopts(const char *shareopts, char **plinux_opts)
+{
+	int rc;
+
+	assert(plinux_opts != NULL);
+
+	*plinux_opts = NULL;
+
+	/* default options for Solaris shares */
+	(void) add_linux_shareopt(plinux_opts, "no_subtree_check", NULL);
+	(void) add_linux_shareopt(plinux_opts, "no_root_squash", NULL);
+	(void) add_linux_shareopt(plinux_opts, "mountpoint", NULL);
+
+	rc = foreach_nfs_shareopt(shareopts, get_linux_shareopts_cb, plinux_opts);
+
+	if (rc != SA_OK) {
+		free(*plinux_opts);
+		*plinux_opts = NULL;
+	}
+
+	return rc;
+}
+
+static int
+nfs_enable_share(sa_share_impl_t impl_share)
+{
+	char *shareopts, *linux_opts;
+	int rc;
+
+	if (!nfs_available) {
+		return SA_SYSTEM_ERR;
+	}
+
+	shareopts = FSINFO(impl_share, nfs_fstype)->shareopts;
+
+	if (shareopts == NULL)
+		return SA_OK;
+
+	rc = get_linux_shareopts(shareopts, &linux_opts);
+
+	if (rc != SA_OK)
+		return rc;
+
+	rc = foreach_nfs_host(impl_share, nfs_enable_share_one, linux_opts);
+
+	free(linux_opts);
+
+	return rc;
+}
+
+static int
+nfs_disable_share_one(const char *sharepath, const char *host,
+    const char *security, const char *access, void *cookie)
+{
+	pid_t pid;
+	int rc, status;
+	char *linuxhost, *hostpath;
+
+	pid = fork();
+
+	if (pid < 0)
+		return SA_SYSTEM_ERR;
+
+	if (pid > 0) {
+		while ((rc = waitpid(pid, &status, 0)) <= 0 && errno == EINTR)
+			; /* empty loop body */
+
+		if (rc <= 0)
+			return SA_SYSTEM_ERR;
+
+		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+			return SA_CONFIG_ERR;
+
+		return SA_OK;
+	}
+
+	/* child */
+
+	rc = get_linux_hostspec(host, &linuxhost);
+
+	if (rc < 0)
+		exit(1);
+
+	hostpath = malloc(strlen(linuxhost) + 1 + strlen(sharepath) + 1);
+
+	if (hostpath == NULL) {
+		free(linuxhost);
+		exit(1);
+	}
+
+	sprintf(hostpath, "%s:%s", linuxhost, sharepath);
+
+	free(linuxhost);
+
+#ifdef DEBUG
+	fprintf(stderr, "unsharing %s\n", hostpath);
+#endif
+
+	rc = execlp("/usr/sbin/exportfs", "exportfs", "-u", \
+	    hostpath, NULL);
+
+	if (rc < 0) {
+		free(hostpath);
+		exit(1);
+	}
+
+	exit(0);
+}
+
+static int
+nfs_disable_share(sa_share_impl_t impl_share)
+{
+	if (!nfs_available) {
+		/*
+		 * The share can't possibly be active, so nothing
+		 * needs to be done to disable it.
+		 */
+		return SA_OK;
+	}
+
+	return foreach_nfs_host(impl_share, nfs_disable_share_one, NULL);
+}
+
+static int
+nfs_validate_shareopts(const char *shareopts)
+{
+	char *linux_opts;
+	int rc;
+
+	rc = get_linux_shareopts(shareopts, &linux_opts);
+
+	if (rc != SA_OK)
+		return rc;
+
+	free(linux_opts);
+
+	return SA_OK;
+}
+
+/*
+ * TODO: Rather than invoking "exportfs -v" once for each share we should only
+ * call it once for all shares.
+ */
+static boolean_t
+is_share_active(sa_share_impl_t impl_share)
+{
+	pid_t pid;
+	int rc, status;
+	int pipes[2];
+	FILE *exportfs_stdout;
+	char line[512];
+	char *tab, *cur;
+	boolean_t share_active = B_FALSE;
+
+	if (pipe(pipes) < 0)
+		return B_FALSE;
+
+	pid = fork();
+
+	if (pid < 0)
+		return B_FALSE;
+
+	if (pid > 0) {
+		share_active = B_FALSE;
+
+		exportfs_stdout = fdopen(pipes[0], "r");
+		close(pipes[1]);
+
+		while (fgets(line, sizeof(line), exportfs_stdout) != NULL) {
+			if (share_active)
+				continue;
+
+			/*
+			 * exportfs uses separate lines for the share path
+			 * and the export options when the share path is longer
+			 * than a certain amount of characters; this ignores
+			 * the option lines
+			 */
+			if (line[0] == '\t')
+				continue;
+
+			tab = strchr(line, '\t');
+
+			if (tab != NULL) {
+				*tab = '\0';
+				cur = tab - 1;
+			} else {
+				/*
+				 * there's no tab character, which means the
+				 * NFS options are on a separate line; we just
+				 * need to remove the new-line character
+				 * at the end of the line
+				 */
+				cur = line + strlen(line) - 1;
+			}
+
+			/* remove trailing spaces and new-line characters */
+			while (cur >= line &&
+			    (*cur == ' ' || *cur == '\n'))
+				*cur-- = '\0';
+
+			if (strcmp(line, impl_share->sharepath) == 0) {
+				share_active = B_TRUE;
+
+				/*
+				 * We can't break here just yet, otherwise
+				 * exportfs might die due to write() failing
+				 * with EPIPE once we've closed the pipe file
+				 * descriptor - we need to read until EOF
+				 * occurs on the stdout pipe.
+				 */
+			}
+		}
+
+		fclose(exportfs_stdout);
+
+		while ((rc = waitpid(pid, &status, 0)) <= 0 && errno == EINTR)
+			; /* empty loop body */
+
+		if (rc <= 0)
+			return B_FALSE;
+
+		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+			return B_FALSE;
+
+		return share_active;
+	}
+
+	/* child */
+
+	/* exportfs -v */
+
+	close(pipes[0]);
+
+	if (dup2(pipes[1], STDOUT_FILENO) < 0)
+		exit(1);
+
+	rc = execlp("/usr/sbin/exportfs", "exportfs", "-v", NULL);
+
+	if (rc < 0) {
+		exit(1);
+	}
+
+	exit(0);
+}
+
+static int
+nfs_update_shareopts(sa_share_impl_t impl_share, const char *resource,
+    const char *shareopts)
+{
+	char *shareopts_dup;
+	boolean_t needs_reshare = B_FALSE;
+	char *old_shareopts;
+
+	FSINFO(impl_share, nfs_fstype)->active = is_share_active(impl_share);
+
+	old_shareopts = FSINFO(impl_share, nfs_fstype)->shareopts;
+
+	if (strcmp(shareopts, "on") == 0)
+		shareopts = "rw";
+
+	if (FSINFO(impl_share, nfs_fstype)->active && old_shareopts != NULL &&
+	    strcmp(old_shareopts, shareopts) != 0) {
+		needs_reshare = B_TRUE;
+		nfs_disable_share(impl_share);
+	}
+
+	shareopts_dup = strdup(shareopts);
+
+	if (shareopts_dup == NULL)
+		return SA_NO_MEMORY;
+
+	if (old_shareopts != NULL)
+		free(old_shareopts);
+
+	FSINFO(impl_share, nfs_fstype)->shareopts = shareopts_dup;
+
+	if (needs_reshare)
+		nfs_enable_share(impl_share);
+
+	return SA_OK;
+}
+
+
+static void
+nfs_clear_shareopts(sa_share_impl_t impl_share)
+{
+	free(FSINFO(impl_share, nfs_fstype)->shareopts);
+	FSINFO(impl_share, nfs_fstype)->shareopts = NULL;
+}
+
+static const sa_share_ops_t nfs_shareops = {
+	.enable_share = nfs_enable_share,
+	.disable_share = nfs_disable_share,
+
+	.validate_shareopts = nfs_validate_shareopts,
+	.update_shareopts = nfs_update_shareopts,
+	.clear_shareopts = nfs_clear_shareopts,
+};
+
+static int
+nfs_check_exportfs(void)
+{
+	pid_t pid;
+	int rc, status, null_fd;
+
+	pid = fork();
+
+	if (pid < 0)
+		return SA_SYSTEM_ERR;
+
+	if (pid > 0) {
+		while ((rc = waitpid(pid, &status, 0)) <= 0 && errno == EINTR)
+			; /* empty loop body */
+
+		if (rc <= 0)
+			return SA_SYSTEM_ERR;
+
+		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+			return SA_CONFIG_ERR;
+
+		return SA_OK;
+	}
+
+	/* child */
+
+	null_fd = open("/dev/null", O_RDONLY);
+
+	if (null_fd < 0 || dup2(null_fd, 1) < 0 || dup2(null_fd, 2) < 0)
+		exit(1);
+
+	close(null_fd);
+
+	rc = execlp("/usr/sbin/exportfs", "exportfs", NULL);
+
+	if (rc < 0) {
+		exit(1);
+	}
+
+	exit(0);
+}
+
+void
+libshare_nfs_init(void)
+{
+	nfs_available = (nfs_check_exportfs() == SA_OK);
+
+	nfs_fstype = register_fstype("nfs", &nfs_shareops);
+}