Unix SMB/CIFS implementation.
uid/user handling
Copyright (C) Andrew Tridgell 1992-1998
-
+
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/passwd.h"
+#include "smbd/smbd.h"
+#include "smbd/globals.h"
+#include "../librpc/gen_ndr/netlogon.h"
+#include "libcli/security/security.h"
+#include "passdb/lookup_sid.h"
+#include "auth.h"
/* what user is current? */
extern struct current_user current_user;
bool change_to_guest(void)
{
- static struct passwd *pass=NULL;
+ struct passwd *pass;
+ pass = Get_Pwnam_alloc(talloc_tos(), lp_guest_account());
if (!pass) {
- /* Don't need to free() this as its stored in a static */
- pass = getpwnam_alloc(NULL, lp_guestaccount());
- if (!pass)
- return(False);
+ return false;
}
-
+
#ifdef AIX
/* MWW: From AIX FAQ patch to WU-ftpd: call initgroups before
setting IDs */
initgroups(pass->pw_name, pass->pw_gid);
#endif
-
+
set_sec_ctx(pass->pw_uid, pass->pw_gid, 0, NULL, NULL);
-
+
current_user.conn = NULL;
current_user.vuid = UID_FIELD_INVALID;
TALLOC_FREE(pass);
- pass = NULL;
-
- return True;
+
+ return true;
}
-/*******************************************************************
- Check if a username is OK.
-********************************************************************/
+/****************************************************************************
+ talloc free the conn->session_info if not used in the vuid cache.
+****************************************************************************/
-static bool check_user_ok(connection_struct *conn, user_struct *vuser,int snum)
+static void free_conn_session_info_if_unused(connection_struct *conn)
{
unsigned int i;
- struct vuid_cache_entry *ent = NULL;
- bool readonly_share;
- NT_USER_TOKEN *token;
- for (i=0; i<VUID_CACHE_SIZE; i++) {
- ent = &conn->vuid_cache.array[i];
- if (ent->vuid == vuser->vuid) {
- conn->read_only = ent->read_only;
- conn->admin_user = ent->admin_user;
- return(True);
+ for (i = 0; i < VUID_CACHE_SIZE; i++) {
+ struct vuid_cache_entry *ent;
+ ent = &conn->vuid_cache->array[i];
+ if (ent->vuid != UID_FIELD_INVALID &&
+ conn->session_info == ent->session_info) {
+ return;
}
}
+ /* Not used, safe to free. */
+ TALLOC_FREE(conn->session_info);
+}
- if (!user_ok_token(vuser->server_info->unix_name,
- vuser->server_info->ptok,
- snum))
- return(False);
+/****************************************************************************
+ Setup the share access mask for a connection.
+****************************************************************************/
- readonly_share = is_share_read_only_for_token(
- vuser->server_info->unix_name, vuser->server_info->ptok,
- SNUM(conn));
+static uint32_t create_share_access_mask(int snum,
+ bool readonly_share,
+ const struct security_token *token)
+{
+ uint32_t share_access = 0;
+
+ share_access_check(token,
+ lp_servicename(talloc_tos(), snum),
+ MAXIMUM_ALLOWED_ACCESS,
+ &share_access);
+
+ if (readonly_share) {
+ share_access &=
+ ~(SEC_FILE_WRITE_DATA | SEC_FILE_APPEND_DATA |
+ SEC_FILE_WRITE_EA | SEC_FILE_WRITE_ATTRIBUTE |
+ SEC_DIR_DELETE_CHILD );
+ }
- token = conn->nt_user_token ?
- conn->nt_user_token : vuser->server_info->ptok;
+ if (security_token_has_privilege(token, SEC_PRIV_SECURITY)) {
+ share_access |= SEC_FLAG_SYSTEM_SECURITY;
+ }
+ if (security_token_has_privilege(token, SEC_PRIV_RESTORE)) {
+ share_access |= SEC_RIGHTS_PRIV_RESTORE;
+ }
+ if (security_token_has_privilege(token, SEC_PRIV_BACKUP)) {
+ share_access |= SEC_RIGHTS_PRIV_BACKUP;
+ }
+ if (security_token_has_privilege(token, SEC_PRIV_TAKE_OWNERSHIP)) {
+ share_access |= SEC_STD_WRITE_OWNER;
+ }
+
+ return share_access;
+}
+
+/*******************************************************************
+ Calculate access mask and if this user can access this share.
+********************************************************************/
+
+NTSTATUS check_user_share_access(connection_struct *conn,
+ const struct auth_session_info *session_info,
+ uint32_t *p_share_access,
+ bool *p_readonly_share)
+{
+ int snum = SNUM(conn);
+ uint32_t share_access = 0;
+ bool readonly_share = false;
+
+ if (!user_ok_token(session_info->unix_info->unix_name,
+ session_info->info->domain_name,
+ session_info->security_token, snum)) {
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ readonly_share = is_share_read_only_for_token(
+ session_info->unix_info->unix_name,
+ session_info->info->domain_name,
+ session_info->security_token,
+ conn);
+
+ share_access = create_share_access_mask(snum,
+ readonly_share,
+ session_info->security_token);
+
+ if ((share_access & (FILE_READ_DATA|FILE_WRITE_DATA)) == 0) {
+ /* No access, read or write. */
+ DEBUG(3,("user %s connection to %s denied due to share "
+ "security descriptor.\n",
+ session_info->unix_info->unix_name,
+ lp_servicename(talloc_tos(), snum)));
+ return NT_STATUS_ACCESS_DENIED;
+ }
if (!readonly_share &&
- !share_access_check(token, lp_servicename(snum),
- FILE_WRITE_DATA)) {
+ !(share_access & FILE_WRITE_DATA)) {
/* smb.conf allows r/w, but the security descriptor denies
* write. Fall back to looking at readonly. */
readonly_share = True;
"security descriptor\n"));
}
- if (!share_access_check(token, lp_servicename(snum),
- readonly_share ?
- FILE_READ_DATA : FILE_WRITE_DATA)) {
- return False;
+ *p_share_access = share_access;
+ *p_readonly_share = readonly_share;
+
+ return NT_STATUS_OK;
+}
+
+/*******************************************************************
+ Check if a username is OK.
+
+ This sets up conn->session_info with a copy related to this vuser that
+ later code can then mess with.
+********************************************************************/
+
+static bool check_user_ok(connection_struct *conn,
+ uint64_t vuid,
+ const struct auth_session_info *session_info,
+ int snum)
+{
+ unsigned int i;
+ bool readonly_share = false;
+ bool admin_user = false;
+ struct vuid_cache_entry *ent = NULL;
+ uint32_t share_access = 0;
+ NTSTATUS status;
+
+ for (i=0; i<VUID_CACHE_SIZE; i++) {
+ ent = &conn->vuid_cache->array[i];
+ if (ent->vuid == vuid) {
+ if (vuid == UID_FIELD_INVALID) {
+ /*
+ * Slow path, we don't care
+ * about the array traversal.
+ */
+ continue;
+ }
+ free_conn_session_info_if_unused(conn);
+ conn->session_info = ent->session_info;
+ conn->read_only = ent->read_only;
+ conn->share_access = ent->share_access;
+ return(True);
+ }
+ }
+
+ status = check_user_share_access(conn,
+ session_info,
+ &share_access,
+ &readonly_share);
+ if (!NT_STATUS_IS_OK(status)) {
+ return false;
}
- ent = &conn->vuid_cache.array[conn->vuid_cache.next_entry];
+ admin_user = token_contains_name_in_list(
+ session_info->unix_info->unix_name,
+ session_info->info->domain_name,
+ NULL, session_info->security_token, lp_admin_users(snum));
+
+ ent = &conn->vuid_cache->array[conn->vuid_cache->next_entry];
+
+ conn->vuid_cache->next_entry =
+ (conn->vuid_cache->next_entry + 1) % VUID_CACHE_SIZE;
+
+ TALLOC_FREE(ent->session_info);
+
+ /*
+ * If force_user was set, all session_info's are based on the same
+ * username-based faked one.
+ */
+
+ ent->session_info = copy_session_info(
+ conn, conn->force_user ? conn->session_info : session_info);
- conn->vuid_cache.next_entry =
- (conn->vuid_cache.next_entry + 1) % VUID_CACHE_SIZE;
+ if (ent->session_info == NULL) {
+ ent->vuid = UID_FIELD_INVALID;
+ return false;
+ }
- ent->vuid = vuser->vuid;
+ /*
+ * It's actually OK to call check_user_ok() with
+ * vuid == UID_FIELD_INVALID as called from change_to_user_by_session().
+ * All this will do is throw away one entry in the cache.
+ */
+
+ ent->vuid = vuid;
ent->read_only = readonly_share;
+ ent->share_access = share_access;
+ free_conn_session_info_if_unused(conn);
+ conn->session_info = ent->session_info;
+ if (vuid == UID_FIELD_INVALID) {
+ /*
+ * Not strictly needed, just make it really
+ * clear this entry is actually an unused one.
+ */
+ ent->read_only = false;
+ ent->share_access = 0;
+ ent->session_info = NULL;
+ }
- ent->admin_user = token_contains_name_in_list(
- vuser->server_info->unix_name, NULL, vuser->server_info->ptok,
- lp_admin_users(SNUM(conn)));
+ conn->read_only = readonly_share;
+ conn->share_access = share_access;
- conn->read_only = ent->read_only;
- conn->admin_user = ent->admin_user;
+ if (admin_user) {
+ DEBUG(2,("check_user_ok: user %s is an admin user. "
+ "Setting uid as %d\n",
+ conn->session_info->unix_info->unix_name,
+ sec_initial_uid() ));
+ conn->session_info->unix_token->uid = sec_initial_uid();
+ }
return(True);
}
stack, but modify the current_user entries.
****************************************************************************/
-bool change_to_user(connection_struct *conn, uint16 vuid)
+static bool change_to_user_internal(connection_struct *conn,
+ const struct auth_session_info *session_info,
+ uint64_t vuid)
{
- user_struct *vuser = get_valid_user_struct(vuid);
int snum;
gid_t gid;
uid_t uid;
char group_c;
- bool must_free_token = False;
- NT_USER_TOKEN *token = NULL;
int num_groups = 0;
gid_t *group_list = NULL;
-
- if (!conn) {
- DEBUG(2,("change_to_user: Connection not open\n"));
- return(False);
- }
-
- /*
- * We need a separate check in security=share mode due to vuid
- * always being UID_FIELD_INVALID. If we don't do this then
- * in share mode security we are *always* changing uid's between
- * SMB's - this hurts performance - Badly.
- */
-
- if((lp_security() == SEC_SHARE) && (current_user.conn == conn) &&
- (current_user.ut.uid == conn->uid)) {
- DEBUG(4,("change_to_user: Skipping user change - already "
- "user\n"));
- return(True);
- } else if ((current_user.conn == conn) &&
- (vuser != 0) && (current_user.vuid == vuid) &&
- (current_user.ut.uid == vuser->server_info->uid)) {
- DEBUG(4,("change_to_user: Skipping user change - already "
- "user\n"));
- return(True);
- }
+ bool ok;
snum = SNUM(conn);
- if ((vuser) && !check_user_ok(conn, vuser, snum)) {
- DEBUG(2,("change_to_user: SMB user %s (unix user %s, vuid %d) "
+ ok = check_user_ok(conn, vuid, session_info, snum);
+ if (!ok) {
+ DEBUG(2,("SMB user %s (unix user %s) "
"not permitted access to share %s.\n",
- vuser->server_info->sanitized_username,
- vuser->server_info->unix_name, vuid,
- lp_servicename(snum)));
- return False;
+ session_info->unix_info->sanitized_username,
+ session_info->unix_info->unix_name,
+ lp_servicename(talloc_tos(), snum)));
+ return false;
}
- if (conn->force_user) /* security = share sets this too */ {
- uid = conn->uid;
- gid = conn->gid;
- group_list = conn->groups;
- num_groups = conn->ngroups;
- token = conn->nt_user_token;
- } else if (vuser) {
- uid = conn->admin_user ? 0 : vuser->server_info->uid;
- gid = vuser->server_info->gid;
- num_groups = vuser->server_info->n_groups;
- group_list = vuser->server_info->groups;
- token = vuser->server_info->ptok;
- } else {
- DEBUG(2,("change_to_user: Invalid vuid used %d in accessing "
- "share %s.\n",vuid, lp_servicename(snum) ));
- return False;
- }
+ uid = conn->session_info->unix_token->uid;
+ gid = conn->session_info->unix_token->gid;
+ num_groups = conn->session_info->unix_token->ngroups;
+ group_list = conn->session_info->unix_token->groups;
/*
- * See if we should force group for this service.
- * If so this overrides any group set in the force
- * user code.
+ * See if we should force group for this service. If so this overrides
+ * any group set in the force user code.
*/
+ if((group_c = *lp_force_group(talloc_tos(), snum))) {
- if((group_c = *lp_force_group(snum))) {
+ SMB_ASSERT(conn->force_group_gid != (gid_t)-1);
- token = dup_nt_token(NULL, token);
- if (token == NULL) {
- DEBUG(0, ("dup_nt_token failed\n"));
- return False;
- }
- must_free_token = True;
-
- if(group_c == '+') {
+ if (group_c == '+') {
+ int i;
/*
- * Only force group if the user is a member of
- * the service group. Check the group memberships for
- * this user (we already have this) to
- * see if we should force the group.
+ * Only force group if the user is a member of the
+ * service group. Check the group memberships for this
+ * user (we already have this) to see if we should force
+ * the group.
*/
-
- int i;
for (i = 0; i < num_groups; i++) {
- if (group_list[i] == conn->gid) {
- gid = conn->gid;
- gid_to_sid(&token->user_sids[1], gid);
+ if (group_list[i] == conn->force_group_gid) {
+ conn->session_info->unix_token->gid =
+ conn->force_group_gid;
+ gid = conn->force_group_gid;
+ gid_to_sid(&conn->session_info->security_token
+ ->sids[1], gid);
break;
}
}
} else {
- gid = conn->gid;
- gid_to_sid(&token->user_sids[1], gid);
+ conn->session_info->unix_token->gid = conn->force_group_gid;
+ gid = conn->force_group_gid;
+ gid_to_sid(&conn->session_info->security_token->sids[1],
+ gid);
}
}
-
- /* Now set current_user since we will immediately also call
- set_sec_ctx() */
+ /*Set current_user since we will immediately also call set_sec_ctx() */
current_user.ut.ngroups = num_groups;
- current_user.ut.groups = group_list;
-
- set_sec_ctx(uid, gid, current_user.ut.ngroups, current_user.ut.groups,
- token);
+ current_user.ut.groups = group_list;
- /*
- * Free the new token (as set_sec_ctx copies it).
- */
-
- if (must_free_token)
- TALLOC_FREE(token);
+ set_sec_ctx(uid,
+ gid,
+ current_user.ut.ngroups,
+ current_user.ut.groups,
+ conn->session_info->security_token);
current_user.conn = conn;
current_user.vuid = vuid;
- DEBUG(5,("change_to_user uid=(%d,%d) gid=(%d,%d)\n",
- (int)getuid(),(int)geteuid(),(int)getgid(),(int)getegid()));
-
- return(True);
+ DEBUG(5, ("Impersonated user: uid=(%d,%d), gid=(%d,%d)\n",
+ (int)getuid(),
+ (int)geteuid(),
+ (int)getgid(),
+ (int)getegid()));
+
+ return true;
+}
+
+bool change_to_user(connection_struct *conn, uint64_t vuid)
+{
+ struct user_struct *vuser;
+ int snum = SNUM(conn);
+
+ if (!conn) {
+ DEBUG(2,("Connection not open\n"));
+ return(False);
+ }
+
+ vuser = get_valid_user_struct(conn->sconn, vuid);
+
+ if ((current_user.conn == conn) &&
+ (vuser != NULL) && (current_user.vuid == vuid) &&
+ (current_user.ut.uid == vuser->session_info->unix_token->uid)) {
+ DEBUG(4,("Skipping user change - already "
+ "user\n"));
+ return(True);
+ }
+
+ if (vuser == NULL) {
+ /* Invalid vuid sent */
+ DEBUG(2,("Invalid vuid %llu used on share %s.\n",
+ (unsigned long long)vuid, lp_servicename(talloc_tos(),
+ snum)));
+ return false;
+ }
+
+ return change_to_user_internal(conn, vuser->session_info, vuid);
+}
+
+static bool change_to_user_by_session(connection_struct *conn,
+ const struct auth_session_info *session_info)
+{
+ SMB_ASSERT(conn != NULL);
+ SMB_ASSERT(session_info != NULL);
+
+ if ((current_user.conn == conn) &&
+ (current_user.ut.uid == session_info->unix_token->uid)) {
+ DEBUG(7, ("Skipping user change - already user\n"));
+
+ return true;
+ }
+
+ return change_to_user_internal(conn, session_info, UID_FIELD_INVALID);
}
/****************************************************************************
but modify the current_user entries.
****************************************************************************/
-bool change_to_root_user(void)
+bool smbd_change_to_root_user(void)
{
set_root_sec_ctx();
user. Doesn't modify current_user.
****************************************************************************/
-bool become_authenticated_pipe_user(pipes_struct *p)
+bool smbd_become_authenticated_pipe_user(struct auth_session_info *session_info)
{
if (!push_sec_ctx())
return False;
- set_sec_ctx(p->pipe_user.ut.uid, p->pipe_user.ut.gid,
- p->pipe_user.ut.ngroups, p->pipe_user.ut.groups,
- p->pipe_user.nt_user_token);
+ set_sec_ctx(session_info->unix_token->uid, session_info->unix_token->gid,
+ session_info->unix_token->ngroups, session_info->unix_token->groups,
+ session_info->security_token);
+
+ DEBUG(5, ("Impersonated user: uid=(%d,%d), gid=(%d,%d)\n",
+ (int)getuid(),
+ (int)geteuid(),
+ (int)getgid(),
+ (int)getegid()));
return True;
}
current_user.
****************************************************************************/
-bool unbecome_authenticated_pipe_user(void)
+bool smbd_unbecome_authenticated_pipe_user(void)
{
return pop_sec_ctx();
}
Utility functions used by become_xxx/unbecome_xxx.
****************************************************************************/
-struct conn_ctx {
- connection_struct *conn;
- uint16 vuid;
-};
-
-/* A stack of current_user connection contexts. */
-
-static struct conn_ctx conn_ctx_stack[MAX_SEC_CTX_DEPTH];
-static int conn_ctx_stack_ndx;
-
static void push_conn_ctx(void)
{
struct conn_ctx *ctx_p;
-
+
/* Check we don't overflow our stack */
-
+
if (conn_ctx_stack_ndx == MAX_SEC_CTX_DEPTH) {
DEBUG(0, ("Connection context stack overflow!\n"));
smb_panic("Connection context stack overflow!\n");
}
-
+
/* Store previous user context */
ctx_p = &conn_ctx_stack[conn_ctx_stack_ndx];
-
+
ctx_p->conn = current_user.conn;
ctx_p->vuid = current_user.vuid;
-
- DEBUG(3, ("push_conn_ctx(%u) : conn_ctx_stack_ndx = %d\n",
- (unsigned int)ctx_p->vuid, conn_ctx_stack_ndx ));
+
+ DEBUG(4, ("push_conn_ctx(%llu) : conn_ctx_stack_ndx = %d\n",
+ (unsigned long long)ctx_p->vuid, conn_ctx_stack_ndx));
conn_ctx_stack_ndx++;
}
static void pop_conn_ctx(void)
{
struct conn_ctx *ctx_p;
-
+
/* Check for stack underflow. */
if (conn_ctx_stack_ndx == 0) {
restores the connection context.
****************************************************************************/
-void become_root(void)
+void smbd_become_root(void)
{
/*
* no good way to handle push_sec_ctx() failing without changing
/* Unbecome the root user */
-void unbecome_root(void)
+void smbd_unbecome_root(void)
{
pop_sec_ctx();
pop_conn_ctx();
Saves and restores the connection context.
****************************************************************************/
-bool become_user(connection_struct *conn, uint16 vuid)
+bool become_user(connection_struct *conn, uint64_t vuid)
{
if (!push_sec_ctx())
return False;
return True;
}
+bool become_user_by_session(connection_struct *conn,
+ const struct auth_session_info *session_info)
+{
+ if (!push_sec_ctx())
+ return false;
+
+ push_conn_ctx();
+
+ if (!change_to_user_by_session(conn, session_info)) {
+ pop_sec_ctx();
+ pop_conn_ctx();
+ return false;
+ }
+
+ return true;
+}
+
bool unbecome_user(void)
{
pop_sec_ctx();
pop_conn_ctx();
return True;
}
+
+/****************************************************************************
+ Return the current user we are running effectively as on this connection.
+ I'd like to make this return conn->session_info->unix_token->uid, but become_root()
+ doesn't alter this value.
+****************************************************************************/
+
+uid_t get_current_uid(connection_struct *conn)
+{
+ return current_user.ut.uid;
+}
+
+/****************************************************************************
+ Return the current group we are running effectively as on this connection.
+ I'd like to make this return conn->session_info->unix_token->gid, but become_root()
+ doesn't alter this value.
+****************************************************************************/
+
+gid_t get_current_gid(connection_struct *conn)
+{
+ return current_user.ut.gid;
+}
+
+/****************************************************************************
+ Return the UNIX token we are running effectively as on this connection.
+ I'd like to make this return &conn->session_info->unix_token-> but become_root()
+ doesn't alter this value.
+****************************************************************************/
+
+const struct security_unix_token *get_current_utok(connection_struct *conn)
+{
+ return ¤t_user.ut;
+}
+
+/****************************************************************************
+ Return the Windows token we are running effectively as on this connection.
+ If this is currently a NULL token as we're inside become_root() - a temporary
+ UNIX security override, then we search up the stack for the previous active
+ token.
+****************************************************************************/
+
+const struct security_token *get_current_nttok(connection_struct *conn)
+{
+ if (current_user.nt_user_token) {
+ return current_user.nt_user_token;
+ }
+ return sec_ctx_active_token();
+}
+
+uint64_t get_current_vuid(connection_struct *conn)
+{
+ return current_user.vuid;
+}
git.samba.org / amitay / samba.git / blobdiff