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 auth_session_info *session_info =
  46                 session->global->auth_session_info;
  47         const char *username;
  48         const char *hostname;
  49         unsigned int id_num;
  50         fstring id_str;
  51
  52         /* don't register sessions for the guest user - its just too
  53            expensive to go through pam session code for browsing etc */
  54         if (security_session_user_level(session_info, NULL) < SECURITY_USER) {
  55                 return true;
  56         }
  57
  58         id_num = session->global->session_global_id;
  59
  60         snprintf(id_str, sizeof(id_str), "smb/%u", id_num);
  61
  62         /* Make clear that we require the optional unix_token in the source3 code */
  63         SMB_ASSERT(session_info->unix_token);
  64
  65         username = session_info->unix_info->unix_name;
  66         hostname = session->global->channels[0].remote_name;
  67
  68         if (!smb_pam_claim_session(username, id_str, hostname)) {
  69                 DEBUG(1,("pam_session rejected the session for %s [%s]\n",
  70                                 username, id_str));
  71                 return false;
  72         }
  73
  74         if (lp_utmp()) {
  75                 sys_utmp_claim(username, hostname, id_str, id_num);
  76         }
  77
  78         return true;
  79 }
  80
  81 /********************************************************************
  82  called when a session is destroyed
  83 ********************************************************************/
  84
  85 void session_yield(struct smbXsrv_session *session)
  86 {
  87         struct auth_session_info *session_info =
  88                 session->global->auth_session_info;
  89         const char *username;
  90         const char *hostname;
  91         unsigned int id_num;
  92         fstring id_str = "";
  93
  94         id_num = session->global->session_global_id;
  95
  96         snprintf(id_str, sizeof(id_str), "smb/%u", id_num);
  97
  98         /* Make clear that we require the optional unix_token in the source3 code */
  99         SMB_ASSERT(session_info->unix_token);
 100
 101         username = session_info->unix_info->unix_name;
 102         hostname = session->global->channels[0].remote_name;
 103
 104         if (lp_utmp()) {
 105                 sys_utmp_yield(username, hostname, id_str, id_num);
 106         }
 107
 108         smb_pam_close_session(username, id_str, hostname);
 109 }
 110
 111 /********************************************************************
 112 ********************************************************************/
 113
 114 struct session_list {
 115         TALLOC_CTX *mem_ctx;
 116         int count;
 117         const char *filter_user;
 118         const char *filter_machine;
 119         struct sessionid *sessions;
 120 };
 121
 122 static int gather_sessioninfo(const char *key, struct sessionid *session,
 123                               void *private_data)
 124 {
 125         struct session_list *sesslist = (struct session_list *)private_data;
 126
 127         /* filter the session if required */
 128
 129         if (sesslist->filter_user &&
 130             (sesslist->filter_user[0] != '\0') &&
 131             !strequal(session->username, sesslist->filter_user)) {
 132                 return 0;
 133         }
 134
 135         if (sesslist->filter_machine &&
 136             (sesslist->filter_machine[0] != '\0') &&
 137             !strequal(session->remote_machine,
 138                       sesslist->filter_machine)) {
 139                 return 0;
 140         }
 141
 142         if (!process_exists(session->pid)) {
 143                 return 0;
 144         }
 145
 146         sesslist->sessions = talloc_realloc(
 147                 sesslist->mem_ctx, sesslist->sessions, struct sessionid,
 148                 sesslist->count+1);
 149
 150         if (!sesslist->sessions) {
 151                 sesslist->count = 0;
 152                 return -1;
 153         }
 154
 155         memcpy(&sesslist->sessions[sesslist->count], session,
 156                sizeof(struct sessionid));
 157
 158         sesslist->count++;
 159
 160         DEBUG(7, ("gather_sessioninfo session from %s@%s\n",
 161                   session->username, session->remote_machine));
 162
 163         return 0;
 164 }
 165
 166 /********************************************************************
 167 ********************************************************************/
 168
 169 int list_sessions(TALLOC_CTX *mem_ctx, struct sessionid **session_list)
 170 {
 171         struct session_list sesslist;
 172         NTSTATUS status;
 173
 174         sesslist.mem_ctx = mem_ctx;
 175         sesslist.count = 0;
 176         sesslist.filter_user = NULL;
 177         sesslist.filter_machine = NULL;
 178         sesslist.sessions = NULL;
 179
 180         status = sessionid_traverse_read(gather_sessioninfo, (void *) &sesslist);
 181         if (!NT_STATUS_IS_OK(status)) {
 182                 DBG_ERR("Session traverse failed: %s\n", nt_errstr(status));
 183                 TALLOC_FREE(sesslist.sessions);
 184                 *session_list = NULL;
 185                 return 0;
 186         }
 187
 188         *session_list = sesslist.sessions;
 189         return sesslist.count;
 190 }
 191
 192 /********************************************************************
 193 find the sessions that match the given username and machine
 194 ********************************************************************/
 195
 196 int find_sessions(TALLOC_CTX *mem_ctx, const char *username,
 197                   const char *machine, struct sessionid **session_list)
 198 {
 199         struct session_list sesslist;
 200         NTSTATUS status;
 201
 202         sesslist.mem_ctx = mem_ctx;
 203         sesslist.count = 0;
 204         sesslist.filter_user = username;
 205         sesslist.filter_machine = machine;
 206         sesslist.sessions = NULL;
 207
 208         status = sessionid_traverse_read(gather_sessioninfo, (void *)&sesslist);
 209         if (!NT_STATUS_IS_OK(status)) {
 210                 DEBUG(3, ("Session traverse failed: %s\n", nt_errstr(status)));
 211                 TALLOC_FREE(sesslist.sessions);
 212                 *session_list = NULL;
 213                 return 0;
 214         }
 215
 216         *session_list = sesslist.sessions;
 217         return sesslist.count;
 218 }