Revert "smbd: implement smbd_impersonate_{conn_vuid,conn_sess,root,guest}_create...
[samba.git] / source3 / smbd / uid.c
index 98020561acfd110d7938f570e1788bfe5d1dca97..e7f0a8f620b8bd89b5221e998600c278c4489744 100644 (file)
 #include "libcli/security/security.h"
 #include "passdb/lookup_sid.h"
 #include "auth.h"
+#include "../auth/auth_util.h"
+#include "lib/util/time_basic.h"
+
+struct smbd_impersonate_debug_state {
+       int dbg_lvl;
+       const char *name;
+};
+
+static bool smbd_impersonate_debug_before_use(struct tevent_context *wrap_ev,
+                                             void *private_data,
+                                             struct tevent_context *main_ev,
+                                             const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev, location));
+
+       return true;
+}
+
+static void smbd_impersonate_debug_after_use(struct tevent_context *wrap_ev,
+                                            void *private_data,
+                                            struct tevent_context *main_ev,
+                                            const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev, location));
+}
+
+static void smbd_impersonate_debug_before_fd_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_fd *fde,
+                                               uint16_t flags,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "fde[%p] flags[0x%X] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev,
+             fde, flags, handler_name, location));
+}
+
+static void smbd_impersonate_debug_after_fd_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_fd *fde,
+                                               uint16_t flags,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "fde[%p] flags[0x%X] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev,
+             fde, flags, handler_name, location));
+}
+
+static void smbd_impersonate_debug_before_timer_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_timer *te,
+                                               struct timeval requested_time,
+                                               struct timeval trigger_time,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+       struct timeval_buf requested_buf;
+       struct timeval_buf trigger_buf;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "te[%p] requested_time[%s] trigger_time[%s] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev, te,
+             timeval_str_buf(&requested_time, true, true, &requested_buf),
+             timeval_str_buf(&trigger_time, true, true, &trigger_buf),
+             handler_name, location));
+}
+
+static void smbd_impersonate_debug_after_timer_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_timer *te,
+                                               struct timeval requested_time,
+                                               struct timeval trigger_time,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+       struct timeval_buf requested_buf;
+       struct timeval_buf trigger_buf;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "te[%p] requested_time[%s] trigger_time[%s] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev, te,
+             timeval_str_buf(&requested_time, true, true, &requested_buf),
+             timeval_str_buf(&trigger_time, true, true, &trigger_buf),
+             handler_name, location));
+}
+
+static void smbd_impersonate_debug_before_immediate_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_immediate *im,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "im[%p] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev,
+             im, handler_name, location));
+}
+
+static void smbd_impersonate_debug_after_immediate_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_immediate *im,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "im[%p] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev,
+             im, handler_name, location));
+}
+
+static void smbd_impersonate_debug_before_signal_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_signal *se,
+                                               int signum,
+                                               int count,
+                                               void *siginfo,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "se[%p] signum[%d] count[%d] siginfo[%p] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev,
+             se, signum, count, siginfo, handler_name, location));
+}
+
+static void smbd_impersonate_debug_after_signal_handler(struct tevent_context *wrap_ev,
+                                               void *private_data,
+                                               struct tevent_context *main_ev,
+                                               struct tevent_signal *se,
+                                               int signum,
+                                               int count,
+                                               void *siginfo,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       struct smbd_impersonate_debug_state *state =
+               (struct smbd_impersonate_debug_state *)private_data;
+
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] "
+             "se[%p] signum[%d] count[%d] siginfo[%p] handler_name[%s] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev,
+             se, signum, count, siginfo, handler_name, location));
+}
+
+static const struct tevent_wrapper_ops smbd_impersonate_debug_ops = {
+       .name                           = "smbd_impersonate_debug",
+       .before_use                     = smbd_impersonate_debug_before_use,
+       .after_use                      = smbd_impersonate_debug_after_use,
+       .before_fd_handler              = smbd_impersonate_debug_before_fd_handler,
+       .after_fd_handler               = smbd_impersonate_debug_after_fd_handler,
+       .before_timer_handler           = smbd_impersonate_debug_before_timer_handler,
+       .after_timer_handler            = smbd_impersonate_debug_after_timer_handler,
+       .before_immediate_handler       = smbd_impersonate_debug_before_immediate_handler,
+       .after_immediate_handler        = smbd_impersonate_debug_after_immediate_handler,
+       .before_signal_handler          = smbd_impersonate_debug_before_signal_handler,
+       .after_signal_handler           = smbd_impersonate_debug_after_signal_handler,
+};
+
+struct tevent_context *_smbd_impersonate_debug_create(struct tevent_context *main_ev,
+                                                     const char *name,
+                                                     int dbg_lvl,
+                                                     const char *location)
+{
+       struct tevent_context *wrap_ev = NULL;
+       struct smbd_impersonate_debug_state *state = NULL;
+
+       wrap_ev = tevent_context_wrapper_create(main_ev,
+                                       main_ev,
+                                       &smbd_impersonate_debug_ops,
+                                       &state,
+                                       struct smbd_impersonate_debug_state);
+       if (wrap_ev == NULL) {
+               return NULL;
+       }
+       state->name = name;
+       state->dbg_lvl = dbg_lvl;
+       DEBUG(state->dbg_lvl, (
+             "%s: name[%s] wrap_ev[%p] state[%p] main_ev[%p] location[%s]\n",
+             __func__, state->name, wrap_ev, state, main_ev, location));
+
+       return wrap_ev;
+}
 
 /* what user is current? */
 extern struct current_user current_user;
@@ -37,7 +267,7 @@ bool change_to_guest(void)
 {
        struct passwd *pass;
 
-       pass = Get_Pwnam_alloc(talloc_tos(), lp_guestaccount());
+       pass = Get_Pwnam_alloc(talloc_tos(), lp_guest_account());
        if (!pass) {
                return false;
        }
@@ -52,6 +282,8 @@ bool change_to_guest(void)
 
        current_user.conn = NULL;
        current_user.vuid = UID_FIELD_INVALID;
+       current_user.need_chdir = false;
+       current_user.done_chdir = false;
 
        TALLOC_FREE(pass);
 
@@ -75,9 +307,48 @@ static void free_conn_session_info_if_unused(connection_struct *conn)
                }
        }
        /* Not used, safe to free. */
+       TALLOC_FREE(conn->user_ev_ctx);
        TALLOC_FREE(conn->session_info);
 }
 
+/****************************************************************************
+  Setup the share access mask for a connection.
+****************************************************************************/
+
+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_const_servicename(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 );
+       }
+
+       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.
 ********************************************************************/
@@ -107,25 +378,22 @@ NTSTATUS check_user_share_access(connection_struct *conn,
                                        readonly_share,
                                        session_info->security_token);
 
-       if ((share_access & FILE_WRITE_DATA) == 0) {
-               if ((share_access & FILE_READ_DATA) == 0) {
-                       /* No access, read or write. */
-                       DEBUG(0,("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 ((share_access & (FILE_READ_DATA|FILE_WRITE_DATA)) == 0) {
+               /* No access, read or write. */
+               DBG_NOTICE("user %s connection to %s denied due to share "
+                        "security descriptor.\n",
+                        session_info->unix_info->unix_name,
+                        lp_const_servicename(snum));
+               return NT_STATUS_ACCESS_DENIED;
        }
 
        if (!readonly_share &&
            !(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;
-               DEBUG(5,("falling back to read-only access-evaluation due to "
-                        "security descriptor\n"));
+               readonly_share = true;
+               DBG_INFO("falling back to read-only access-evaluation due to "
+                        "security descriptor\n");
        }
 
        *p_share_access = share_access;
@@ -151,52 +419,34 @@ static bool check_user_ok(connection_struct *conn,
        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->user_ev_ctx = ent->user_ev_ctx;
                        conn->read_only = ent->read_only;
                        conn->share_access = ent->share_access;
+                       conn->vuid = ent->vuid;
                        return(True);
                }
        }
 
-       if (!user_ok_token(session_info->unix_info->unix_name,
-                          session_info->info->domain_name,
-                          session_info->security_token, snum))
-               return(False);
-
-       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_WRITE_DATA) == 0) {
-               if ((share_access & FILE_READ_DATA) == 0) {
-                       /* No access, read or write. */
-                       DEBUG(0,("user %s connection to %s "
-                               "denied due to share security "
-                               "descriptor.\n",
-                               session_info->unix_info->unix_name,
-                               lp_servicename(talloc_tos(), snum)));
-                       return false;
-               }
-       }
-
-       if (!readonly_share &&
-           !(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;
-               DEBUG(5,("falling back to read-only access-evaluation due to "
-                        "security descriptor\n"));
+       status = check_user_share_access(conn,
+                                       session_info,
+                                       &share_access,
+                                       &readonly_share);
+       if (!NT_STATUS_IS_OK(status)) {
+               return false;
        }
 
        admin_user = token_contains_name_in_list(
@@ -224,23 +474,59 @@ static bool check_user_ok(connection_struct *conn,
                return false;
        }
 
+       if (admin_user) {
+               DEBUG(2,("check_user_ok: user %s is an admin user. "
+                       "Setting uid as %d\n",
+                       ent->session_info->unix_info->unix_name,
+                       sec_initial_uid() ));
+               ent->session_info->unix_token->uid = sec_initial_uid();
+       }
+
+       if (vuid == UID_FIELD_INVALID) {
+               ent->user_ev_ctx = smbd_impersonate_conn_sess_create(
+                       conn->sconn->raw_ev_ctx, conn, ent->session_info);
+               if (ent->user_ev_ctx == NULL) {
+                       TALLOC_FREE(ent->session_info);
+                       ent->vuid = UID_FIELD_INVALID;
+                       return false;
+               }
+       } else {
+               ent->user_ev_ctx = smbd_impersonate_conn_vuid_create(
+                       conn->sconn->raw_ev_ctx, conn, vuid);
+               if (ent->user_ev_ctx == NULL) {
+                       TALLOC_FREE(ent->session_info);
+                       ent->vuid = UID_FIELD_INVALID;
+                       return false;
+               }
+       }
+
+       /*
+        * 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;
+       conn->vuid = ent->vuid;
+       conn->user_ev_ctx = ent->user_ev_ctx;
+       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->user_ev_ctx = NULL;
+       }
 
        conn->read_only = readonly_share;
        conn->share_access = share_access;
 
-       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);
 }
 
@@ -261,15 +547,28 @@ static bool change_to_user_internal(connection_struct *conn,
        gid_t *group_list = NULL;
        bool ok;
 
+       if ((current_user.conn == conn) &&
+           (current_user.vuid == vuid) &&
+           (current_user.need_chdir == conn->tcon_done) &&
+           (current_user.ut.uid == session_info->unix_token->uid))
+       {
+               DBG_INFO("Skipping user change - already user\n");
+               return true;
+       }
+
+       set_current_user_info(session_info->unix_info->sanitized_username,
+                             session_info->unix_info->unix_name,
+                             session_info->info->domain_name);
+
        snum = SNUM(conn);
 
        ok = check_user_ok(conn, vuid, session_info, snum);
        if (!ok) {
-               DEBUG(2,("SMB user %s (unix user %s) "
+               DBG_WARNING("SMB user %s (unix user %s) "
                         "not permitted access to share %s.\n",
                         session_info->unix_info->sanitized_username,
                         session_info->unix_info->unix_name,
-                        lp_servicename(talloc_tos(), snum)));
+                        lp_const_servicename(snum));
                return false;
        }
 
@@ -325,12 +624,30 @@ static bool change_to_user_internal(connection_struct *conn,
 
        current_user.conn = conn;
        current_user.vuid = vuid;
+       current_user.need_chdir = conn->tcon_done;
 
-       DEBUG(5, ("Impersonated user: uid=(%d,%d), gid=(%d,%d)\n",
-                (int)getuid(),
-                (int)geteuid(),
-                (int)getgid(),
-                (int)getegid()));
+       if (current_user.need_chdir) {
+               ok = chdir_current_service(conn);
+               if (!ok) {
+                       DBG_ERR("chdir_current_service() failed!\n");
+                       return false;
+               }
+               current_user.done_chdir = true;
+       }
+
+       if (CHECK_DEBUGLVL(DBGLVL_INFO)) {
+               struct smb_filename *cwdfname = vfs_GetWd(talloc_tos(), conn);
+               if (cwdfname == NULL) {
+                       return false;
+               }
+               DBG_INFO("Impersonated user: uid=(%d,%d), gid=(%d,%d), cwd=[%s]\n",
+                        (int)getuid(),
+                        (int)geteuid(),
+                        (int)getgid(),
+                        (int)getegid(),
+                        cwdfname->base_name);
+               TALLOC_FREE(cwdfname);
+       }
 
        return true;
 }
@@ -346,39 +663,28 @@ bool change_to_user(connection_struct *conn, uint64_t vuid)
        }
 
        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)));
+               DBG_WARNING("Invalid vuid %llu used on share %s.\n",
+                           (unsigned long long)vuid,
+                           lp_const_servicename(snum));
                return false;
        }
 
        return change_to_user_internal(conn, vuser->session_info, vuid);
 }
 
+bool change_to_user_by_fsp(struct files_struct *fsp)
+{
+       return change_to_user(fsp->conn, fsp->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);
 }
 
@@ -396,6 +702,8 @@ bool smbd_change_to_root_user(void)
 
        current_user.conn = NULL;
        current_user.vuid = UID_FIELD_INVALID;
+       current_user.need_chdir = false;
+       current_user.done_chdir = false;
 
        return(True);
 }
@@ -406,7 +714,7 @@ bool smbd_change_to_root_user(void)
  user. Doesn't modify current_user.
 ****************************************************************************/
 
-bool become_authenticated_pipe_user(struct auth_session_info *session_info)
+bool smbd_become_authenticated_pipe_user(struct auth_session_info *session_info)
 {
        if (!push_sec_ctx())
                return False;
@@ -415,6 +723,12 @@ bool become_authenticated_pipe_user(struct auth_session_info *session_info)
                    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;
 }
 
@@ -425,7 +739,7 @@ bool become_authenticated_pipe_user(struct auth_session_info *session_info)
  current_user.
 ****************************************************************************/
 
-bool unbecome_authenticated_pipe_user(void)
+bool smbd_unbecome_authenticated_pipe_user(void)
 {
        return pop_sec_ctx();
 }
@@ -437,6 +751,7 @@ bool unbecome_authenticated_pipe_user(void)
 static void push_conn_ctx(void)
 {
        struct conn_ctx *ctx_p;
+       extern userdom_struct current_user_info;
 
        /* Check we don't overflow our stack */
 
@@ -450,6 +765,9 @@ static void push_conn_ctx(void)
 
        ctx_p->conn = current_user.conn;
        ctx_p->vuid = current_user.vuid;
+       ctx_p->need_chdir = current_user.need_chdir;
+       ctx_p->done_chdir = current_user.done_chdir;
+       ctx_p->user_info = current_user_info;
 
        DEBUG(4, ("push_conn_ctx(%llu) : conn_ctx_stack_ndx = %d\n",
                (unsigned long long)ctx_p->vuid, conn_ctx_stack_ndx));
@@ -471,11 +789,33 @@ static void pop_conn_ctx(void)
        conn_ctx_stack_ndx--;
        ctx_p = &conn_ctx_stack[conn_ctx_stack_ndx];
 
+       set_current_user_info(ctx_p->user_info.smb_name,
+                             ctx_p->user_info.unix_name,
+                             ctx_p->user_info.domain);
+
+       /*
+        * Check if the current context did a chdir_current_service()
+        * and restore the cwd_fname of the previous context
+        * if needed.
+        */
+       if (current_user.done_chdir && ctx_p->need_chdir) {
+               int ret;
+
+               ret = vfs_ChDir(ctx_p->conn, ctx_p->conn->cwd_fname);
+               if (ret != 0) {
+                       DBG_ERR("vfs_ChDir() failed!\n");
+                       smb_panic("vfs_ChDir() failed!\n");
+               }
+       }
+
        current_user.conn = ctx_p->conn;
        current_user.vuid = ctx_p->vuid;
+       current_user.need_chdir = ctx_p->need_chdir;
+       current_user.done_chdir = ctx_p->done_chdir;
 
-       ctx_p->conn = NULL;
-       ctx_p->vuid = UID_FIELD_INVALID;
+       *ctx_p = (struct conn_ctx) {
+               .vuid = UID_FIELD_INVALID,
+       };
 }
 
 /****************************************************************************
@@ -504,6 +844,34 @@ void smbd_unbecome_root(void)
        pop_conn_ctx();
 }
 
+bool become_guest(void)
+{
+       bool ok;
+
+       ok = push_sec_ctx();
+       if (!ok) {
+               return false;
+       }
+
+       push_conn_ctx();
+
+       ok = change_to_guest();
+       if (!ok) {
+               pop_sec_ctx();
+               pop_conn_ctx();
+               return false;
+       }
+
+       return true;
+}
+
+void unbecome_guest(void)
+{
+       pop_sec_ctx();
+       pop_conn_ctx();
+       return;
+}
+
 /****************************************************************************
  Push the current security context then force a change via change_to_user().
  Saves and restores the connection context.
@@ -525,6 +893,11 @@ bool become_user(connection_struct *conn, uint64_t vuid)
        return True;
 }
 
+bool become_user_by_fsp(struct files_struct *fsp)
+{
+       return become_user(fsp->conn, fsp->vuid);
+}
+
 bool become_user_by_session(connection_struct *conn,
                            const struct auth_session_info *session_info)
 {
@@ -601,3 +974,53 @@ uint64_t get_current_vuid(connection_struct *conn)
 {
        return current_user.vuid;
 }
+
+struct tevent_context *smbd_impersonate_conn_vuid_create(
+                               struct tevent_context *main_ev,
+                               struct connection_struct *conn,
+                               uint64_t vuid)
+{
+       struct tevent_context *wrap_ev = NULL;
+
+       wrap_ev = smbd_impersonate_debug_create(main_ev,
+                                               "conn_vuid",
+                                               DBGLVL_DEBUG);
+
+       return wrap_ev;
+}
+
+struct tevent_context *smbd_impersonate_conn_sess_create(
+                               struct tevent_context *main_ev,
+                               struct connection_struct *conn,
+                               struct auth_session_info *session_info)
+{
+       struct tevent_context *wrap_ev = NULL;
+
+       wrap_ev = smbd_impersonate_debug_create(main_ev,
+                                               "conn_sess",
+                                               DBGLVL_DEBUG);
+
+       return wrap_ev;
+}
+
+struct tevent_context *smbd_impersonate_root_create(struct tevent_context *main_ev)
+{
+       struct tevent_context *wrap_ev = NULL;
+
+       wrap_ev = smbd_impersonate_debug_create(main_ev,
+                                               "root",
+                                               DBGLVL_DEBUG);
+
+       return wrap_ev;
+}
+
+struct tevent_context *smbd_impersonate_guest_create(struct tevent_context *main_ev)
+{
+       struct tevent_context *wrap_ev = NULL;
+
+       wrap_ev = smbd_impersonate_debug_create(main_ev,
+                                               "guest",
+                                               DBGLVL_DEBUG);
+
+       return wrap_ev;
+}