source3/smbd/session.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    session handling for utmp and PAM
   4
   5    Copyright (C) tridge@samba.org       2001
   6    Copyright (C) abartlet@samba.org     2001
   7    Copyright (C) Gerald (Jerry) Carter  2006
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 /* a "session" is claimed when we do a SessionSetupX operation
  24    and is yielded when the corresponding vuid is destroyed.
  25
  26    sessions are used to populate utmp and PAM session structures
  27 */
  28
  29 #include "includes.h"
  30 #include "smbd/smbd.h"
  31 #include "smbd/globals.h"
  32 #include "dbwrap/dbwrap.h"
  33 #include "session.h"
  34 #include "auth.h"
  35 #include "../lib/tsocket/tsocket.h"
  36 #include "../libcli/security/security.h"
  37 #include "messages.h"
  38
  39 /********************************************************************
  40  called when a session is created
  41 ********************************************************************/
  42
  43 bool session_claim(struct smbXsrv_session *session)
  44 {
  45         struct user_struct *vuser = session->compat;
  46         struct smbd_server_connection *sconn = session->connection->sconn;
  47         struct server_id pid = messaging_server_id(sconn->msg_ctx);
  48         TDB_DATA data;
  49         struct sessionid sessionid;
  50         fstring keystr;
  51         struct db_record *rec;
  52         NTSTATUS status;
  53         char *raddr;
  54
  55         vuser->session_keystr = NULL;
  56
  57         /* don't register sessions for the guest user - its just too
  58            expensive to go through pam session code for browsing etc */
  59         if (security_session_user_level(vuser->session_info, NULL) < SECURITY_USER) {
  60                 return True;
  61         }
  62
  63         if (!sessionid_init()) {
  64                 return False;
  65         }
  66
  67         ZERO_STRUCT(sessionid);
  68
  69         sessionid.id_num = session->global->session_global_id;
  70
  71         data.dptr = NULL;
  72         data.dsize = 0;
  73
  74         snprintf(keystr, sizeof(keystr), "ID/%u", sessionid.id_num);
  75         snprintf(sessionid.id_str, sizeof(sessionid.id_str),
  76                  "smb/%u", sessionid.id_num);
  77
  78         rec = sessionid_fetch_record(NULL, keystr);
  79         if (rec == NULL) {
  80                 DEBUG(1, ("Could not lock \"%s\"\n", keystr));
  81                 return False;
  82         }
  83
  84         raddr = tsocket_address_inet_addr_string(session->connection->remote_address,
  85                                                  talloc_tos());
  86         if (raddr == NULL) {
  87                 return false;
  88         }
  89
  90         /* Make clear that we require the optional unix_token in the source3 code */
  91         SMB_ASSERT(vuser->session_info->unix_token);
  92
  93         fstrcpy(sessionid.username, vuser->session_info->unix_info->unix_name);
  94         fstrcpy(sessionid.hostname, sconn->remote_hostname);
  95         sessionid.pid = pid;
  96         sessionid.uid = vuser->session_info->unix_token->uid;
  97         sessionid.gid = vuser->session_info->unix_token->gid;
  98         fstrcpy(sessionid.remote_machine, get_remote_machine_name());
  99         fstrcpy(sessionid.ip_addr_str, raddr);
 100         sessionid.connect_start = time(NULL);
 101
 102         if (!smb_pam_claim_session(sessionid.username, sessionid.id_str,
 103                                    sessionid.hostname)) {
 104                 DEBUG(1,("pam_session rejected the session for %s [%s]\n",
 105                                 sessionid.username, sessionid.id_str));
 106
 107                 TALLOC_FREE(rec);
 108                 return False;
 109         }
 110
 111         data.dptr = (uint8 *)&sessionid;
 112         data.dsize = sizeof(sessionid);
 113
 114         status = dbwrap_record_store(rec, data, TDB_REPLACE);
 115
 116         TALLOC_FREE(rec);
 117
 118         if (!NT_STATUS_IS_OK(status)) {
 119                 DEBUG(1,("session_claim: unable to create session id "
 120                          "record: %s\n", nt_errstr(status)));
 121                 return False;
 122         }
 123
 124         if (lp_utmp()) {
 125                 sys_utmp_claim(sessionid.username, sessionid.hostname,
 126                                sessionid.id_str, sessionid.id_num);
 127         }
 128
 129         vuser->session_keystr = talloc_strdup(vuser, keystr);
 130         if (!vuser->session_keystr) {
 131                 DEBUG(0, ("session_claim:  talloc_strdup() failed for session_keystr\n"));
 132                 return False;
 133         }
 134         return True;
 135 }
 136
 137 /********************************************************************
 138  called when a session is destroyed
 139 ********************************************************************/
 140
 141 void session_yield(struct smbXsrv_session *session)
 142 {
 143         struct user_struct *vuser = session->compat;
 144         struct sessionid sessionid;
 145         struct db_record *rec;
 146         TDB_DATA value;
 147
 148         if (!vuser->session_keystr) {
 149                 return;
 150         }
 151
 152         rec = sessionid_fetch_record(NULL, vuser->session_keystr);
 153         if (rec == NULL) {
 154                 return;
 155         }
 156
 157         value = dbwrap_record_get_value(rec);
 158
 159         if (value.dsize != sizeof(sessionid))
 160                 return;
 161
 162         memcpy(&sessionid, value.dptr, sizeof(sessionid));
 163
 164         if (lp_utmp()) {
 165                 sys_utmp_yield(sessionid.username, sessionid.hostname,
 166                                sessionid.id_str, sessionid.id_num);
 167         }
 168
 169         smb_pam_close_session(sessionid.username, sessionid.id_str,
 170                               sessionid.hostname);
 171
 172         dbwrap_record_delete(rec);
 173
 174         TALLOC_FREE(rec);
 175 }
 176
 177 /********************************************************************
 178 ********************************************************************/
 179
 180 struct session_list {
 181         TALLOC_CTX *mem_ctx;
 182         int count;
 183         struct sessionid *sessions;
 184 };
 185
 186 static int gather_sessioninfo(const char *key, struct sessionid *session,
 187                               void *private_data)
 188 {
 189         struct session_list *sesslist = (struct session_list *)private_data;
 190
 191         sesslist->sessions = talloc_realloc(
 192                 sesslist->mem_ctx, sesslist->sessions, struct sessionid,
 193                 sesslist->count+1);
 194
 195         if (!sesslist->sessions) {
 196                 sesslist->count = 0;
 197                 return -1;
 198         }
 199
 200         memcpy(&sesslist->sessions[sesslist->count], session,
 201                sizeof(struct sessionid));
 202
 203         sesslist->count++;
 204
 205         DEBUG(7, ("gather_sessioninfo session from %s@%s\n",
 206                   session->username, session->remote_machine));
 207
 208         return 0;
 209 }
 210
 211 /********************************************************************
 212 ********************************************************************/
 213
 214 int list_sessions(TALLOC_CTX *mem_ctx, struct sessionid **session_list)
 215 {
 216         struct session_list sesslist;
 217         NTSTATUS status;
 218
 219         sesslist.mem_ctx = mem_ctx;
 220         sesslist.count = 0;
 221         sesslist.sessions = NULL;
 222
 223         status = sessionid_traverse_read(gather_sessioninfo, (void *) &sesslist);
 224         if (!NT_STATUS_IS_OK(status)) {
 225                 DEBUG(3, ("Session traverse failed\n"));
 226                 SAFE_FREE(sesslist.sessions);
 227                 *session_list = NULL;
 228                 return 0;
 229         }
 230
 231         *session_list = sesslist.sessions;
 232         return sesslist.count;
 233 }