src/ngircd/login.c

   1 /*
   2  * ngIRCd -- The Next Generation IRC Daemon
   3  * Copyright (c)2001-2012 Alexander Barton (alex@barton.de) and Contributors.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  * Please read the file COPYING, README and AUTHORS for more information.
  10  */
  11
  12 #include "portab.h"
  13
  14 /**
  15  * @file
  16  * Functions to deal with client logins
  17  */
  18
  19 #include "imp.h"
  20 #include <assert.h>
  21 #include <stdlib.h>
  22 #include <strings.h>
  23 #include <unistd.h>
  24
  25 #include "defines.h"
  26 #include "conn.h"
  27 #include "class.h"
  28 #include "client.h"
  29 #include "client-cap.h"
  30 #include "channel.h"
  31 #include "conf.h"
  32 #include "io.h"
  33 #include "parse.h"
  34 #include "log.h"
  35 #include "messages.h"
  36 #include "ngircd.h"
  37 #include "pam.h"
  38 #include "irc-info.h"
  39 #include "irc-write.h"
  40
  41 #include "exp.h"
  42 #include "login.h"
  43
  44 #ifdef PAM
  45 static void cb_Read_Auth_Result PARAMS((int r_fd, UNUSED short events));
  46 #endif
  47
  48 /**
  49  * Initiate client login.
  50  *
  51  * This function is called after the daemon received the required NICK and
  52  * USER commands of a new client. If the daemon is compiled with support for
  53  * PAM, the authentication sub-processs is forked; otherwise the global server
  54  * password is checked.
  55  *
  56  * @param Client The client logging in.
  57  * @returns CONNECTED or DISCONNECTED.
  58  */
  59 GLOBAL bool
  60 Login_User(CLIENT * Client)
  61 {
  62 #ifdef PAM
  63         int pipefd[2], result;
  64         pid_t pid;
  65 #endif
  66         CONN_ID conn;
  67
  68         assert(Client != NULL);
  69         conn = Client_Conn(Client);
  70
  71 #ifndef STRICT_RFC
  72         if (Conf_AuthPing) {
  73                 /* Did we receive the "auth PONG" already? */
  74                 if (Conn_GetAuthPing(conn)) {
  75                         Client_SetType(Client, CLIENT_WAITAUTHPING);
  76                         LogDebug("Connection %d: Waiting for AUTH PONG ...", conn);
  77                         return CONNECTED;
  78                 }
  79         }
  80 #endif
  81
  82         /* Still waiting for "CAP END" command? */
  83         if (Client_Cap(Client) & CLIENT_CAP_PENDING)
  84                 return CONNECTED;
  85
  86 #ifdef PAM
  87         if (!Conf_PAM) {
  88                 /* Don't do any PAM authentication at all, instead emulate
  89                  * the beahiour of the daemon compiled without PAM support:
  90                  * because there can't be any "server password", all
  91                  * passwords supplied are classified as "wrong". */
  92                 if(Client_Password(Client)[0] == '\0')
  93                         return Login_User_PostAuth(Client);
  94                 Client_Reject(Client, "Non-empty password", false);
  95                 return DISCONNECTED;
  96         }
  97
  98         if (Conf_PAMIsOptional && strcmp(Client_Password(Client), "") == 0) {
  99                 /* Clients are not required to send a password and to be PAM-
 100                  * authenticated at all. If not, they won't become "identified"
 101                  * and keep the "~" in their supplied user name.
 102                  * Therefore it is sensible to either set Conf_PAMisOptional or
 103                  * to enable IDENT lookups -- not both. */
 104                 return Login_User_PostAuth(Client);
 105         }
 106
 107         /* Fork child process for PAM authentication; and make sure that the
 108          * process timeout is set higher than the login timeout! */
 109         pid = Proc_Fork(Conn_GetProcStat(conn), pipefd,
 110                         cb_Read_Auth_Result, Conf_PongTimeout + 1);
 111         if (pid > 0) {
 112                 LogDebug("Authenticator for connection %d created (PID %d).",
 113                          conn, pid);
 114                 return CONNECTED;
 115         } else {
 116                 /* Sub process */
 117                 Log_Init_Subprocess("Auth");
 118                 Conn_CloseAllSockets(NONE);
 119                 result = PAM_Authenticate(Client);
 120                 if (write(pipefd[1], &result, sizeof(result)) != sizeof(result))
 121                         Log_Subprocess(LOG_ERR,
 122                                        "Failed to pipe result to parent!");
 123                 Log_Exit_Subprocess("Auth");
 124                 exit(0);
 125         }
 126 #else
 127         /* Check global server password ... */
 128         if (strcmp(Client_Password(Client), Conf_ServerPwd) != 0) {
 129                 /* Bad password! */
 130                 Client_Reject(Client, "Bad server password", false);
 131                 return DISCONNECTED;
 132         }
 133         return Login_User_PostAuth(Client);
 134 #endif
 135 }
 136
 137 /**
 138  * Finish client registration.
 139  *
 140  * Introduce the new client to the network and send all "hello messages"
 141  * to it after authentication has been succeeded.
 142  *
 143  * @param Client The client logging in.
 144  * @return CONNECTED or DISCONNECTED.
 145  */
 146 GLOBAL bool
 147 Login_User_PostAuth(CLIENT *Client)
 148 {
 149         assert(Client != NULL);
 150
 151         if (Class_HandleServerBans(Client) != CONNECTED)
 152                 return DISCONNECTED;
 153
 154         Client_Introduce(NULL, Client, CLIENT_USER);
 155
 156         if (!IRC_WriteStrClient
 157             (Client, RPL_WELCOME_MSG, Client_ID(Client), Client_Mask(Client)))
 158                 return false;
 159         if (!IRC_WriteStrClient
 160             (Client, RPL_YOURHOST_MSG, Client_ID(Client),
 161              Client_ID(Client_ThisServer()), PACKAGE_VERSION, TARGET_CPU,
 162              TARGET_VENDOR, TARGET_OS))
 163                 return false;
 164         if (!IRC_WriteStrClient
 165             (Client, RPL_CREATED_MSG, Client_ID(Client), NGIRCd_StartStr))
 166                 return false;
 167         if (!IRC_WriteStrClient
 168             (Client, RPL_MYINFO_MSG, Client_ID(Client),
 169              Client_ID(Client_ThisServer()), PACKAGE_VERSION, USERMODES,
 170              CHANMODES))
 171                 return false;
 172
 173         /* Features supported by this server (005 numeric, ISUPPORT),
 174          * see <http://www.irc.org/tech_docs/005.html> for details. */
 175         if (!IRC_Send_ISUPPORT(Client))
 176                 return DISCONNECTED;
 177
 178         if (!IRC_Send_LUSERS(Client))
 179                 return DISCONNECTED;
 180         if (!IRC_Show_MOTD(Client))
 181                 return DISCONNECTED;
 182
 183         /* Suspend the client for a second ... */
 184         IRC_SetPenalty(Client, 1);
 185
 186         return CONNECTED;
 187 }
 188
 189 #ifdef PAM
 190
 191 /**
 192  * Read result of the authenticatior sub-process from pipe
 193  *
 194  * @param r_fd          File descriptor of the pipe.
 195  * @param events        (ignored IO specification)
 196  */
 197 static void
 198 cb_Read_Auth_Result(int r_fd, UNUSED short events)
 199 {
 200         CONN_ID conn;
 201         CLIENT *client;
 202         int result;
 203         size_t len;
 204         PROC_STAT *proc;
 205
 206         LogDebug("Auth: Got callback on fd %d, events %d", r_fd, events);
 207         conn = Conn_GetFromProc(r_fd);
 208         if (conn == NONE) {
 209                 /* Ops, none found? Probably the connection has already
 210                  * been closed!? We'll ignore that ... */
 211                 io_close(r_fd);
 212                 LogDebug("Auth: Got callback for unknown connection!?");
 213                 return;
 214         }
 215         proc = Conn_GetProcStat(conn);
 216         client = Conn_GetClient(conn);
 217
 218         /* Read result from pipe */
 219         len = Proc_Read(proc, &result, sizeof(result));
 220         Proc_Close(proc);
 221         if (len == 0)
 222                 return;
 223
 224         if (len != sizeof(result)) {
 225                 Log(LOG_CRIT, "Auth: Got malformed result!");
 226                 Client_Reject(client, "Internal error", false);
 227                 return;
 228         }
 229
 230         if (result == true) {
 231                 Client_SetUser(client, Client_OrigUser(client), true);
 232                 (void)Login_User_PostAuth(client);
 233         } else
 234                 Client_Reject(client, "Bad password", false);
 235 }
 236
 237 #endif
 238
 239 /* -eof- */