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                 Client_SetType(Client, CLIENT_WAITCAPEND);
  85                 LogDebug("Connection %d: Waiting for CAP END ...", conn);
  86                 return CONNECTED;
  87         }
  88
  89 #ifdef PAM
  90         if (!Conf_PAM) {
  91                 /* Don't do any PAM authentication at all, instead emulate
  92                  * the beahiour of the daemon compiled without PAM support:
  93                  * because there can't be any "server password", all
  94                  * passwords supplied are classified as "wrong". */
  95                 if(Client_Password(Client)[0] == '\0')
  96                         return Login_User_PostAuth(Client);
  97                 Client_Reject(Client, "Non-empty password", false);
  98                 return DISCONNECTED;
  99         }
 100
 101         if (Conf_PAMIsOptional && strcmp(Client_Password(Client), "") == 0) {
 102                 /* Clients are not required to send a password and to be PAM-
 103                  * authenticated at all. If not, they won't become "identified"
 104                  * and keep the "~" in their supplied user name.
 105                  * Therefore it is sensible to either set Conf_PAMisOptional or
 106                  * to enable IDENT lookups -- not both. */
 107                 return Login_User_PostAuth(Client);
 108         }
 109
 110         /* Fork child process for PAM authentication; and make sure that the
 111          * process timeout is set higher than the login timeout! */
 112         pid = Proc_Fork(Conn_GetProcStat(conn), pipefd,
 113                         cb_Read_Auth_Result, Conf_PongTimeout + 1);
 114         if (pid > 0) {
 115                 LogDebug("Authenticator for connection %d created (PID %d).",
 116                          conn, pid);
 117                 return CONNECTED;
 118         } else {
 119                 /* Sub process */
 120                 Log_Init_Subprocess("Auth");
 121                 Conn_CloseAllSockets(NONE);
 122                 result = PAM_Authenticate(Client);
 123                 if (write(pipefd[1], &result, sizeof(result)) != sizeof(result))
 124                         Log_Subprocess(LOG_ERR,
 125                                        "Failed to pipe result to parent!");
 126                 Log_Exit_Subprocess("Auth");
 127                 exit(0);
 128         }
 129 #else
 130         /* Check global server password ... */
 131         if (strcmp(Client_Password(Client), Conf_ServerPwd) != 0) {
 132                 /* Bad password! */
 133                 Client_Reject(Client, "Bad server password", false);
 134                 return DISCONNECTED;
 135         }
 136         return Login_User_PostAuth(Client);
 137 #endif
 138 }
 139
 140 /**
 141  * Finish client registration.
 142  *
 143  * Introduce the new client to the network and send all "hello messages"
 144  * to it after authentication has been succeeded.
 145  *
 146  * @param Client The client logging in.
 147  * @return CONNECTED or DISCONNECTED.
 148  */
 149 GLOBAL bool
 150 Login_User_PostAuth(CLIENT *Client)
 151 {
 152         assert(Client != NULL);
 153
 154         if (Class_HandleServerBans(Client) != CONNECTED)
 155                 return DISCONNECTED;
 156
 157         Client_Introduce(NULL, Client, CLIENT_USER);
 158
 159         if (!IRC_WriteStrClient
 160             (Client, RPL_WELCOME_MSG, Client_ID(Client), Client_Mask(Client)))
 161                 return false;
 162         if (!IRC_WriteStrClient
 163             (Client, RPL_YOURHOST_MSG, Client_ID(Client),
 164              Client_ID(Client_ThisServer()), PACKAGE_VERSION, TARGET_CPU,
 165              TARGET_VENDOR, TARGET_OS))
 166                 return false;
 167         if (!IRC_WriteStrClient
 168             (Client, RPL_CREATED_MSG, Client_ID(Client), NGIRCd_StartStr))
 169                 return false;
 170         if (!IRC_WriteStrClient
 171             (Client, RPL_MYINFO_MSG, Client_ID(Client),
 172              Client_ID(Client_ThisServer()), PACKAGE_VERSION, USERMODES,
 173              CHANMODES))
 174                 return false;
 175
 176         /* Features supported by this server (005 numeric, ISUPPORT),
 177          * see <http://www.irc.org/tech_docs/005.html> for details. */
 178         if (!IRC_Send_ISUPPORT(Client))
 179                 return DISCONNECTED;
 180
 181         if (!IRC_Send_LUSERS(Client))
 182                 return DISCONNECTED;
 183         if (!IRC_Show_MOTD(Client))
 184                 return DISCONNECTED;
 185
 186         /* Suspend the client for a second ... */
 187         IRC_SetPenalty(Client, 1);
 188
 189         return CONNECTED;
 190 }
 191
 192 #ifdef PAM
 193
 194 /**
 195  * Read result of the authenticatior sub-process from pipe
 196  *
 197  * @param r_fd          File descriptor of the pipe.
 198  * @param events        (ignored IO specification)
 199  */
 200 static void
 201 cb_Read_Auth_Result(int r_fd, UNUSED short events)
 202 {
 203         CONN_ID conn;
 204         CLIENT *client;
 205         int result;
 206         size_t len;
 207         PROC_STAT *proc;
 208
 209         LogDebug("Auth: Got callback on fd %d, events %d", r_fd, events);
 210         conn = Conn_GetFromProc(r_fd);
 211         if (conn == NONE) {
 212                 /* Ops, none found? Probably the connection has already
 213                  * been closed!? We'll ignore that ... */
 214                 io_close(r_fd);
 215                 LogDebug("Auth: Got callback for unknown connection!?");
 216                 return;
 217         }
 218         proc = Conn_GetProcStat(conn);
 219         client = Conn_GetClient(conn);
 220
 221         /* Read result from pipe */
 222         len = Proc_Read(proc, &result, sizeof(result));
 223         Proc_Close(proc);
 224         if (len == 0)
 225                 return;
 226
 227         if (len != sizeof(result)) {
 228                 Log(LOG_CRIT, "Auth: Got malformed result!");
 229                 Client_Reject(client, "Internal error", false);
 230                 return;
 231         }
 232
 233         if (result == true) {
 234                 Client_SetUser(client, Client_OrigUser(client), true);
 235                 (void)Login_User_PostAuth(client);
 236         } else
 237                 Client_Reject(client, "Bad password", false);
 238 }
 239
 240 #endif
 241
 242 /* -eof- */