Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 588 insertions, 0 deletions

diff --git a/source3/lib/sharesec.c b/source3/lib/sharesec.c
new file mode 100644
index 0000000..fbb2d47
--- /dev/null
+++ b/source3/lib/sharesec.c
@@ -0,0 +1,588 @@
+/* 
+ *  Unix SMB/Netbios implementation.
+ *  SEC_DESC handling functions
+ *  Copyright (C) Jeremy R. Allison            1995-2003.
+ *  
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *  
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *  
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "includes.h"
+#include "system/filesys.h"
+#include "../libcli/security/security.h"
+#include "../librpc/gen_ndr/ndr_security.h"
+#include "dbwrap/dbwrap.h"
+#include "dbwrap/dbwrap_open.h"
+#include "util_tdb.h"
+#include "libcli/util/ntstatus.h"
+
+/*******************************************************************
+ Create the share security tdb.
+ ********************************************************************/
+
+static struct db_context *share_db; /* used for share security descriptors */
+#define SHARE_DATABASE_VERSION_V1 1
+#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */
+#define SHARE_DATABASE_VERSION_V3 3 /* canonicalized sharenames as lower case */
+
+#define SHARE_SECURITY_DB_KEY_PREFIX_STR "SECDESC/"
+/* Map generic permissions to file object specific permissions */
+
+extern const struct generic_mapping file_generic_mapping;
+
+static int delete_fn(struct db_record *rec, void *priv)
+{
+	dbwrap_record_delete(rec);
+	return 0;
+}
+
+/*****************************************************
+ Looking for keys of the form: SHARE_SECURITY_DB_KEY_PREFIX_STR + "non lower case str".
+ If we find one re-write it into a canonical case form.
+*****************************************************/
+
+static int upgrade_v2_to_v3(struct db_record *rec, void *priv)
+{
+	size_t prefix_len = strlen(SHARE_SECURITY_DB_KEY_PREFIX_STR);
+	const char *servicename = NULL;
+	char *c_servicename = NULL;
+	char *newkey = NULL;
+	bool *p_upgrade_ok = (bool *)priv;
+	NTSTATUS status;
+	TDB_DATA key;
+	TDB_DATA value;
+
+	key = dbwrap_record_get_key(rec);
+
+	/* Is there space for a one character sharename ? */
+	if (key.dsize <= prefix_len+2) {
+		return 0;
+	}
+
+	/* Does it start with the share key prefix ? */
+	if (memcmp(key.dptr, SHARE_SECURITY_DB_KEY_PREFIX_STR,
+			prefix_len) != 0) {
+		return 0;
+	}
+
+	/* Is it a null terminated string as a key ? */
+	if (key.dptr[key.dsize-1] != '\0') {
+		return 0;
+	}
+
+	/* Bytes after the prefix are the sharename string. */
+	servicename = (char *)&key.dptr[prefix_len];
+	c_servicename = canonicalize_servicename(talloc_tos(), servicename);
+	if (!c_servicename) {
+		smb_panic("out of memory upgrading share security db from v2 -> v3");
+	}
+
+	if (strcmp(servicename, c_servicename) == 0) {
+		/* Old and new names match. No canonicalization needed. */
+		TALLOC_FREE(c_servicename);
+		return 0;
+	}
+
+	/* Oops. Need to canonicalize name, delete old then store new. */
+	status = dbwrap_record_delete(rec);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("upgrade_v2_to_v3: Failed to delete secdesc for "
+			  "%s: %s\n", (const char *)key.dptr,
+			  nt_errstr(status)));
+		TALLOC_FREE(c_servicename);
+		*p_upgrade_ok = false;
+		return -1;
+	} else {
+		DEBUG(10, ("upgrade_v2_to_v3: deleted secdesc for "
+                          "%s\n", (const char *)key.dptr));
+	}
+
+	if (!(newkey = talloc_asprintf(talloc_tos(),
+			SHARE_SECURITY_DB_KEY_PREFIX_STR "%s",
+			c_servicename))) {
+		smb_panic("out of memory upgrading share security db from v2 -> v3");
+	}
+
+	value = dbwrap_record_get_value(rec);
+	status = dbwrap_store(share_db,
+				string_term_tdb_data(newkey),
+				value,
+				TDB_REPLACE);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("upgrade_v2_to_v3: Failed to store secdesc for "
+			  "%s: %s\n", c_servicename, nt_errstr(status)));
+		TALLOC_FREE(c_servicename);
+		TALLOC_FREE(newkey);
+		*p_upgrade_ok = false;
+		return -1;
+	} else {
+		DEBUG(10, ("upgrade_v2_to_v3: stored secdesc for "
+                          "%s\n", newkey ));
+	}
+
+	TALLOC_FREE(newkey);
+	TALLOC_FREE(c_servicename);
+
+	return 0;
+}
+
+NTSTATUS share_info_db_init(void)
+{
+	const char *vstring = "INFO/version";
+	int32_t vers_id = 0;
+	bool upgrade_ok = true;
+	NTSTATUS status;
+	char *db_path;
+
+	if (share_db != NULL) {
+		return NT_STATUS_OK;
+	}
+
+	db_path = state_path(talloc_tos(), "share_info.tdb");
+	if (db_path == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	share_db = db_open(NULL, db_path, 0,
+			   TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
+			   DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE);
+	if (share_db == NULL) {
+		DEBUG(0,("Failed to open share info database %s (%s)\n",
+			 db_path, strerror(errno)));
+		TALLOC_FREE(db_path);
+		return map_nt_error_from_unix_common(errno);
+	}
+	TALLOC_FREE(db_path);
+
+	status = dbwrap_fetch_int32_bystring(share_db, vstring, &vers_id);
+	if (!NT_STATUS_IS_OK(status)) {
+		vers_id = 0;
+	}
+
+	if (vers_id == SHARE_DATABASE_VERSION_V3) {
+		return NT_STATUS_OK;
+	}
+
+	if (dbwrap_transaction_start(share_db) != 0) {
+		DEBUG(0, ("transaction_start failed\n"));
+		TALLOC_FREE(share_db);
+		return NT_STATUS_INTERNAL_DB_ERROR;
+	}
+
+	status = dbwrap_fetch_int32_bystring(share_db, vstring, &vers_id);
+	if (!NT_STATUS_IS_OK(status)) {
+		vers_id = 0;
+	}
+
+	if (vers_id == SHARE_DATABASE_VERSION_V3) {
+		/*
+		 * Race condition
+		 */
+		if (dbwrap_transaction_cancel(share_db)) {
+			smb_panic("transaction_cancel failed");
+		}
+		return NT_STATUS_OK;
+	}
+
+	/* Move to at least V2. */
+
+	/* Cope with byte-reversed older versions of the db. */
+	if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) {
+		/* Written on a bigendian machine with old fetch_int code. Save as le. */
+
+		status = dbwrap_store_int32_bystring(
+			share_db, vstring, SHARE_DATABASE_VERSION_V2);
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(0, ("dbwrap_store_int32 failed: %s\n",
+				  nt_errstr(status)));
+			goto cancel;
+		}
+		vers_id = SHARE_DATABASE_VERSION_V2;
+	}
+
+	if (vers_id != SHARE_DATABASE_VERSION_V2) {
+		status = dbwrap_traverse(share_db, delete_fn, NULL, NULL);
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(0, ("traverse failed\n"));
+			goto cancel;
+		}
+		status = dbwrap_store_int32_bystring(
+			share_db, vstring, SHARE_DATABASE_VERSION_V2);
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(0, ("dbwrap_store_int32 failed: %s\n",
+				  nt_errstr(status)));
+			goto cancel;
+		}
+	}
+
+	/* Finally upgrade to version 3, with canonicalized sharenames. */
+
+	status = dbwrap_traverse(share_db, upgrade_v2_to_v3, &upgrade_ok, NULL);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("traverse failed\n"));
+		goto cancel;
+	}
+	if (!upgrade_ok) {
+		DBG_ERR("upgrade failed.\n");
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto cancel;
+	}
+
+	status = dbwrap_store_int32_bystring(
+		share_db, vstring, SHARE_DATABASE_VERSION_V3);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("dbwrap_store_int32 failed: %s\n",
+			  nt_errstr(status)));
+		goto cancel;
+	}
+
+	if (dbwrap_transaction_commit(share_db) != 0) {
+		DEBUG(0, ("transaction_commit failed\n"));
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	return NT_STATUS_OK;
+
+ cancel:
+	if (dbwrap_transaction_cancel(share_db)) {
+		smb_panic("transaction_cancel failed");
+	}
+
+	return status;
+}
+
+/*******************************************************************
+ Fake up a Everyone, default access as a default.
+ def_access is a GENERIC_XXX access mode.
+ ********************************************************************/
+
+static struct security_descriptor *get_share_security_default(TALLOC_CTX *ctx,
+							size_t *psize,
+							uint32_t def_access)
+{
+	uint32_t sa;
+	struct security_ace ace;
+	struct security_acl *psa = NULL;
+	struct security_descriptor *psd = NULL;
+	uint32_t spec_access = def_access;
+
+	se_map_generic(&spec_access, &file_generic_mapping);
+
+	sa = (def_access | spec_access );
+	init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0);
+
+	if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) {
+		psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
+				    SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
+				    psa, psize);
+	}
+
+	if (!psd) {
+		DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n"));
+		return NULL;
+	}
+
+	return psd;
+}
+
+/*******************************************************************
+ Pull a security descriptor from the share tdb.
+ ********************************************************************/
+
+struct security_descriptor *get_share_security( TALLOC_CTX *ctx, const char *servicename,
+			      size_t *psize)
+{
+	char *key;
+	struct security_descriptor *psd = NULL;
+	TDB_DATA data;
+	char *c_servicename = canonicalize_servicename(talloc_tos(), servicename);
+	NTSTATUS status;
+
+	if (!c_servicename) {
+		return NULL;
+	}
+
+	status = share_info_db_init();
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(c_servicename);
+		return NULL;
+	}
+
+	if (!(key = talloc_asprintf(ctx, SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_servicename))) {
+		TALLOC_FREE(c_servicename);
+		DEBUG(0, ("talloc_asprintf failed\n"));
+		return NULL;
+	}
+
+	TALLOC_FREE(c_servicename);
+
+	status = dbwrap_fetch_bystring(share_db, talloc_tos(), key, &data);
+
+	TALLOC_FREE(key);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		return get_share_security_default(ctx, psize,
+						  SEC_RIGHTS_DIR_ALL);
+	}
+
+	status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd);
+
+	TALLOC_FREE(data.dptr);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		return get_share_security_default(ctx, psize,
+						  SEC_RIGHTS_DIR_ALL);
+	}
+
+	if (psd) {
+		*psize = ndr_size_security_descriptor(psd, 0);
+	} else {
+		return get_share_security_default(ctx, psize,
+						  SEC_RIGHTS_DIR_ALL);
+	}
+
+	return psd;
+}
+
+/*******************************************************************
+ Store a security descriptor in the share db.
+ ********************************************************************/
+
+NTSTATUS set_share_security(const char *share_name,
+			    struct security_descriptor *psd)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	char *key;
+	TDB_DATA blob;
+	NTSTATUS status;
+	char *c_share_name = canonicalize_servicename(frame, share_name);
+
+	if (c_share_name == NULL) {
+		status = NT_STATUS_INVALID_PARAMETER;
+		goto out;
+	}
+
+	status = share_info_db_init();
+	if (!NT_STATUS_IS_OK(status)) {
+		goto out;
+	}
+
+	status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("marshall_sec_desc failed: %s\n",
+			  nt_errstr(status)));
+		goto out;
+	}
+
+	if (!(key = talloc_asprintf(frame, SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_share_name))) {
+		DEBUG(0, ("talloc_asprintf failed\n"));
+		status = NT_STATUS_NO_MEMORY;
+		goto out;
+	}
+
+	status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob,
+				    TDB_REPLACE);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("set_share_security: Failed to store secdesc for "
+			  "%s: %s\n", share_name, nt_errstr(status)));
+		goto out;
+	}
+
+	DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name ));
+	status = NT_STATUS_OK;
+
+ out:
+	TALLOC_FREE(frame);
+	return status;
+}
+
+/*******************************************************************
+ Delete a security descriptor.
+********************************************************************/
+
+NTSTATUS delete_share_security(const char *servicename)
+{
+	TDB_DATA kbuf;
+	char *key;
+	NTSTATUS status;
+	char *c_servicename = canonicalize_servicename(talloc_tos(), servicename);
+
+	if (c_servicename == NULL) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	status = share_info_db_init();
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(c_servicename);
+		return status;
+	}
+
+	if (!(key = talloc_asprintf(talloc_tos(), SHARE_SECURITY_DB_KEY_PREFIX_STR "%s",
+				    c_servicename))) {
+		TALLOC_FREE(c_servicename);
+		return NT_STATUS_NO_MEMORY;
+	}
+	kbuf = string_term_tdb_data(key);
+
+	status = dbwrap_trans_delete(share_db, kbuf);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("delete_share_security: Failed to delete entry for "
+			  "share %s: %s\n", c_servicename, nt_errstr(status)));
+		TALLOC_FREE(c_servicename);
+		return status;
+	}
+
+	TALLOC_FREE(c_servicename);
+	return NT_STATUS_OK;
+}
+
+/*******************************************************************
+ Can this user access with share with the required permissions ?
+********************************************************************/
+
+bool share_access_check(const struct security_token *token,
+			const char *sharename,
+			uint32_t desired_access,
+			uint32_t *pgranted)
+{
+	uint32_t granted;
+	NTSTATUS status;
+	struct security_descriptor *psd = NULL;
+	size_t sd_size;
+
+	psd = get_share_security(talloc_tos(), sharename, &sd_size);
+
+	if (!psd) {
+		if (pgranted != NULL) {
+			*pgranted = desired_access;
+		}
+		return false;
+	}
+
+	status = se_file_access_check(psd, token, true, desired_access, &granted);
+
+	TALLOC_FREE(psd);
+
+	if (pgranted != NULL) {
+		*pgranted = granted;
+	}
+
+	return NT_STATUS_IS_OK(status);
+}
+
+/***************************************************************************
+ Parse the contents of an acl string from a usershare file.
+***************************************************************************/
+
+bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, struct security_descriptor **ppsd)
+{
+	size_t s_size = 0;
+	const char *pacl = acl_str;
+	int num_aces = 0;
+	struct security_ace *ace_list = NULL;
+	struct security_acl *psa = NULL;
+	struct security_descriptor *psd = NULL;
+	size_t sd_size = 0;
+	int i;
+
+	*ppsd = NULL;
+
+	/* If the acl string is blank return "Everyone:R" */
+	if (!*acl_str) {
+		struct security_descriptor *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS);
+		if (!default_psd) {
+			return False;
+		}
+		*ppsd = default_psd;
+		return True;
+	}
+
+	num_aces = 1;
+
+	/* Add the number of ',' characters to get the number of aces. */
+	num_aces += count_chars(pacl,',');
+
+	ace_list = talloc_array(ctx, struct security_ace, num_aces);
+	if (!ace_list) {
+		return False;
+	}
+
+	for (i = 0; i < num_aces; i++) {
+		uint32_t sa;
+		uint32_t g_access;
+		uint32_t s_access;
+		struct dom_sid sid;
+		char *sidstr;
+		enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED;
+
+		if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) {
+			DEBUG(0,("parse_usershare_acl: malformed usershare acl looking "
+				"for ':' in string '%s'\n", pacl));
+			return False;
+		}
+
+		if (!string_to_sid(&sid, sidstr)) {
+			DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n",
+				sidstr ));
+			return False;
+		}
+
+		switch (*pacl) {
+			case 'F': /* Full Control, ie. R+W */
+			case 'f': /* Full Control, ie. R+W */
+				s_access = g_access = GENERIC_ALL_ACCESS;
+				break;
+			case 'R': /* Read only. */
+			case 'r': /* Read only. */
+				s_access = g_access = GENERIC_READ_ACCESS;
+				break;
+			case 'D': /* Deny all to this SID. */
+			case 'd': /* Deny all to this SID. */
+				type = SEC_ACE_TYPE_ACCESS_DENIED;
+				s_access = g_access = GENERIC_ALL_ACCESS;
+				break;
+			default:
+				DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n",
+					pacl ));
+				return False;
+		}
+
+		pacl++;
+		if (*pacl && *pacl != ',') {
+			DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n",
+				pacl ));
+			return False;
+		}
+		pacl++; /* Go past any ',' */
+
+		se_map_generic(&s_access, &file_generic_mapping);
+		sa = (g_access | s_access);
+		init_sec_ace(&ace_list[i], &sid, type, sa, 0);
+	}
+
+	if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) {
+		psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
+				    SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
+				    psa, &sd_size);
+	}
+
+	if (!psd) {
+		DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n"));
+		return False;
+	}
+
+	*ppsd = psd;
+	return True;
+}