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Diffstat (limited to 'source3/passdb/privileges.c')
| -rw-r--r-- | source3/passdb/privileges.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/source3/passdb/privileges.c b/source3/passdb/privileges.c new file mode 100644 index 0000000000..688053674b --- /dev/null +++ b/source3/passdb/privileges.c @@ -0,0 +1,341 @@ +/* + * Unix SMB/CIFS implementation. + * + * default privileges backend for passdb + * + * Copyright (C) Andrew Tridgell 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 2 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, write to the Free Software Foundation, Inc., 675 + * Mass Ave, Cambridge, MA 02139, USA. + */ + +#include "includes.h" + +/* + this is a local implementation of a privileges backend, with + privileges stored in a tdb. Most passdb implementations will + probably use this backend, although some (such as pdb_ldap) will + store the privileges in another manner. + + The basic principle is that the backend should store a list of SIDs + associated with each right, where a right is a string name such as + 'SeTakeOwnershipPrivilege'. The SIDs can be of any type, and do not + need to belong to the local domain. + + The way this is used is that certain places in the code which + require access control will ask the privileges backend 'does this + user have the following privilege'. The 'user' will be a NT_TOKEN, + which is essentially just a list of SIDs. If any of those SIDs are + listed in the list of SIDs for that privilege then the answer will + be 'yes'. That will usually mean that the user gets unconditional + access to that functionality, regradless of any ACLs. In this way + privileges act in a similar fashion to unix setuid bits. +*/ + +/* + The terms 'right' and 'privilege' are used interchangably in this + file. This follows MSDN convention where the LSA calls are calls on + 'rights', which really means privileges. My apologies for the + confusion. +*/ + + +/* 15 seconds seems like an ample time for timeouts on the privileges db */ +#define LOCK_TIMEOUT 15 + + +/* the tdb handle for the privileges database */ +static TDB_CONTEXT *tdb; + + +/* initialise the privilege database */ +BOOL privilege_init(void) +{ + tdb = tdb_open_log(lock_path("privilege.tdb"), 0, TDB_DEFAULT, + O_RDWR|O_CREAT, 0600); + if (!tdb) { + DEBUG(0,("Failed to open privilege database\n")); + return False; + } + + return True; +} + +/* + lock the record for a particular privilege (write lock) +*/ +static NTSTATUS privilege_lock_right(const char *right) +{ + if (tdb_lock_bystring(tdb, right, LOCK_TIMEOUT) != 0) { + return NT_STATUS_INTERNAL_ERROR; + } + return NT_STATUS_OK; +} + +/* + unlock the record for a particular privilege (write lock) +*/ +static void privilege_unlock_right(const char *right) +{ + tdb_unlock_bystring(tdb, right); +} + + +/* + return a list of SIDs that have a particular right +*/ +NTSTATUS privilege_enum_account_with_right(const char *right, + uint32 *count, + DOM_SID **sids) +{ + TDB_DATA data; + char *p; + int i; + + if (!tdb) { + return NT_STATUS_INTERNAL_ERROR; + } + + data = tdb_fetch_by_string(tdb, right); + if (!data.dptr) { + *count = 0; + *sids = NULL; + return NT_STATUS_OK; + } + + /* count them */ + for (i=0, p=data.dptr; p<data.dptr+data.dsize; i++) { + p += strlen(p) + 1; + } + *count = i; + + /* allocate and parse */ + *sids = malloc(sizeof(DOM_SID) * *count); + if (! *sids) { + return NT_STATUS_NO_MEMORY; + } + for (i=0, p=data.dptr; p<data.dptr+data.dsize; i++) { + if (!string_to_sid(&(*sids)[i], p)) { + free(data.dptr); + return NT_STATUS_INTERNAL_DB_CORRUPTION; + } + p += strlen(p) + 1; + } + + free(data.dptr); + + return NT_STATUS_OK; +} + +/* + set what accounts have a given right - this is an internal interface +*/ +static NTSTATUS privilege_set_accounts_with_right(const char *right, + uint32 count, + DOM_SID *sids) +{ + TDB_DATA data; + char *p; + int i; + + if (!tdb) { + return NT_STATUS_INTERNAL_ERROR; + } + + /* allocate the maximum size that we might use */ + data.dptr = malloc(count * ((MAXSUBAUTHS*11) + 30)); + if (!data.dptr) { + return NT_STATUS_NO_MEMORY; + } + + p = data.dptr; + + for (i=0;i<count;i++) { + sid_to_string(p, &sids[i]); + p += strlen(p) + 1; + } + + data.dsize = PTR_DIFF(p, data.dptr); + + if (tdb_store_by_string(tdb, right, data, TDB_REPLACE) != 0) { + free(data.dptr); + return NT_STATUS_INTERNAL_ERROR; + } + + free(data.dptr); + return NT_STATUS_OK; +} + + +/* + add a SID to the list of SIDs for a right +*/ +NTSTATUS privilege_add_account_right(const char *right, + DOM_SID *sid) +{ + NTSTATUS status; + DOM_SID *current_sids; + uint32 current_count; + int i; + + status = privilege_lock_right(right); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + status = privilege_enum_account_with_right(right, ¤t_count, ¤t_sids); + if (!NT_STATUS_IS_OK(status)) { + privilege_unlock_right(right); + return status; + } + + /* maybe that SID is already listed? this is not an error */ + for (i=0;i<current_count;i++) { + if (sid_equal(¤t_sids[i], sid)) { + privilege_unlock_right(right); + free(current_sids); + return NT_STATUS_OK; + } + } + + /* add it in */ + current_sids = Realloc(current_sids, sizeof(current_sids[0]) * (current_count+1)); + if (!current_sids) { + privilege_unlock_right(right); + return NT_STATUS_NO_MEMORY; + } + + sid_copy(¤t_sids[current_count], sid); + current_count++; + + status = privilege_set_accounts_with_right(right, current_count, current_sids); + + free(current_sids); + privilege_unlock_right(right); + + return status; +} + + +/* + remove a SID from the list of SIDs for a right +*/ +NTSTATUS privilege_remove_account_right(const char *right, + DOM_SID *sid) +{ + NTSTATUS status; + DOM_SID *current_sids; + uint32 current_count; + int i; + + status = privilege_lock_right(right); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + status = privilege_enum_account_with_right(right, ¤t_count, ¤t_sids); + if (!NT_STATUS_IS_OK(status)) { + privilege_unlock_right(right); + return status; + } + + for (i=0;i<current_count;i++) { + if (sid_equal(¤t_sids[i], sid)) { + /* found it - so remove it */ + if (current_count-i > 1) { + memmove(¤t_sids[i], ¤t_sids[i+1], + sizeof(current_sids[0]) * ((current_count-i)-1)); + } + current_count--; + status = privilege_set_accounts_with_right(right, + current_count, + current_sids); + free(current_sids); + privilege_unlock_right(right); + return status; + } + } + + /* removing a right that you don't have is not an error */ + + safe_free(current_sids); + privilege_unlock_right(right); + return NT_STATUS_OK; +} + + +/* + an internal function for checking if a SID has a right +*/ +static BOOL privilege_sid_has_right(DOM_SID *sid, const char *right) +{ + NTSTATUS status; + uint32 count; + DOM_SID *sids; + int i; + + status = privilege_enum_account_with_right(right, &count, &sids); + if (!NT_STATUS_IS_OK(status)) { + return False; + } + for (i=0;i<count;i++) { + if (sid_equal(sid, &sids[i])) { + free(sids); + return True; + } + } + + safe_free(sids); + return False; +} + +/* + list the rights for an account. This involves traversing the database +*/ +NTSTATUS privilege_enum_account_rights(DOM_SID *sid, + uint32 *count, + char ***rights) +{ + TDB_DATA key, nextkey; + char *right; + + if (!tdb) { + return NT_STATUS_INTERNAL_ERROR; + } + + *rights = NULL; + *count = 0; + + for (key = tdb_firstkey(tdb); key.dptr; key = nextkey) { + nextkey = tdb_nextkey(tdb, key); + + right = key.dptr; + + if (privilege_sid_has_right(sid, right)) { + (*rights) = (char **)Realloc(*rights,sizeof(char *) * ((*count)+1)); + if (! *rights) { + safe_free(nextkey.dptr); + free(key.dptr); + return NT_STATUS_NO_MEMORY; + } + + (*rights)[*count] = strdup(right); + (*count)++; + } + + free(key.dptr); + } + + return NT_STATUS_OK; +} |