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 <stdio.h>
  23 #include <string.h>
  24 #include <strings.h>
  25 #include <unistd.h>
  26
  27 #include "defines.h"
  28 #include "conn.h"
  29 #include "class.h"
  30 #include "client.h"
  31 #include "client-cap.h"
  32 #include "channel.h"
  33 #include "conf.h"
  34 #include "io.h"
  35 #include "parse.h"
  36 #include "log.h"
  37 #include "messages.h"
  38 #include "ngircd.h"
  39 #include "pam.h"
  40 #include "irc-info.h"
  41 #include "irc-mode.h"
  42 #include "irc-write.h"
  43
  44 #include "exp.h"
  45 #include "login.h"
  46
  47 #ifdef PAM
  48 static void cb_Read_Auth_Result PARAMS((int r_fd, UNUSED short events));
  49 #endif
  50
  51 /**
  52  * Initiate client login.
  53  *
  54  * This function is called after the daemon received the required NICK and
  55  * USER commands of a new client. If the daemon is compiled with support for
  56  * PAM, the authentication sub-processs is forked; otherwise the global server
  57  * password is checked.
  58  *
  59  * @param Client The client logging in.
  60  * @returns CONNECTED or DISCONNECTED.
  61  */
  62 GLOBAL bool
  63 Login_User(CLIENT * Client)
  64 {
  65 #ifdef PAM
  66         int pipefd[2], result;
  67         pid_t pid;
  68 #endif
  69         CONN_ID conn;
  70
  71         assert(Client != NULL);
  72         conn = Client_Conn(Client);
  73
  74 #ifndef STRICT_RFC
  75         if (Conf_AuthPing) {
  76                 /* Did we receive the "auth PONG" already? */
  77                 if (Conn_GetAuthPing(conn)) {
  78                         Client_SetType(Client, CLIENT_WAITAUTHPING);
  79                         LogDebug("Connection %d: Waiting for AUTH PONG ...", conn);
  80                         return CONNECTED;
  81                 }
  82         }
  83 #endif
  84
  85         /* Still waiting for "CAP END" command? */
  86         if (Client_Cap(Client) & CLIENT_CAP_PENDING) {
  87                 Client_SetType(Client, CLIENT_WAITCAPEND);
  88                 LogDebug("Connection %d: Waiting for CAP END ...", conn);
  89                 return CONNECTED;
  90         }
  91
  92 #ifdef PAM
  93         if (!Conf_PAM) {
  94                 /* Don't do any PAM authentication at all if PAM is not
  95                  * enabled, instead emulate the behavior of the daemon
  96                  * compiled without PAM support. */
  97                 if (strcmp(Conn_Password(conn), Conf_ServerPwd) == 0)
  98                         return Login_User_PostAuth(Client);
  99                 Client_Reject(Client, "Bad server password", false);
 100                 return DISCONNECTED;
 101         }
 102
 103         if (Conf_PAMIsOptional &&
 104             strcmp(Conn_Password(conn), "") == 0) {
 105                 /* Clients are not required to send a password and to be PAM-
 106                  * authenticated at all. If not, they won't become "identified"
 107                  * and keep the "~" in their supplied user name.
 108                  * Therefore it is sensible to either set Conf_PAMisOptional or
 109                  * to enable IDENT lookups -- not both. */
 110                 return Login_User_PostAuth(Client);
 111         }
 112
 113         if (Conf_PAM) {
 114                 /* Fork child process for PAM authentication; and make sure that the
 115                  * process timeout is set higher than the login timeout! */
 116                 pid = Proc_Fork(Conn_GetProcStat(conn), pipefd,
 117                                 cb_Read_Auth_Result, Conf_PongTimeout + 1);
 118                 if (pid > 0) {
 119                         LogDebug("Authenticator for connection %d created (PID %d).",
 120                                  conn, pid);
 121                         return CONNECTED;
 122                 } else {
 123                         /* Sub process */
 124                         Log_Init_Subprocess("Auth");
 125                         Conn_CloseAllSockets(NONE);
 126                         result = PAM_Authenticate(Client);
 127                         if (write(pipefd[1], &result, sizeof(result)) != sizeof(result))
 128                                 Log_Subprocess(LOG_ERR,
 129                                                "Failed to pipe result to parent!");
 130                         Log_Exit_Subprocess("Auth");
 131                         exit(0);
 132                 }
 133         } else return CONNECTED;
 134 #else
 135         /* Check global server password ... */
 136         if (strcmp(Conn_Password(conn), Conf_ServerPwd) != 0) {
 137                 /* Bad password! */
 138                 Client_Reject(Client, "Bad server password", false);
 139                 return DISCONNECTED;
 140         }
 141         return Login_User_PostAuth(Client);
 142 #endif
 143 }
 144
 145 /**
 146  * Finish client registration.
 147  *
 148  * Introduce the new client to the network and send all "hello messages"
 149  * to it after authentication has been succeeded.
 150  *
 151  * @param Client The client logging in.
 152  * @return CONNECTED or DISCONNECTED.
 153  */
 154 GLOBAL bool
 155 Login_User_PostAuth(CLIENT *Client)
 156 {
 157         REQUEST Req;
 158         char modes[CLIENT_MODE_LEN + 1];
 159
 160         assert(Client != NULL);
 161
 162         if (Class_HandleServerBans(Client) != CONNECTED)
 163                 return DISCONNECTED;
 164
 165         Client_Introduce(NULL, Client, CLIENT_USER);
 166
 167         if (!IRC_WriteStrClient
 168             (Client, RPL_WELCOME_MSG, Client_ID(Client), Client_Mask(Client)))
 169                 return false;
 170         if (!IRC_WriteStrClient
 171             (Client, RPL_YOURHOST_MSG, Client_ID(Client),
 172              Client_ID(Client_ThisServer()), PACKAGE_VERSION, HOST_CPU,
 173              HOST_VENDOR, HOST_OS))
 174                 return false;
 175         if (!IRC_WriteStrClient
 176             (Client, RPL_CREATED_MSG, Client_ID(Client), NGIRCd_StartStr))
 177                 return false;
 178         if (!IRC_WriteStrClient
 179             (Client, RPL_MYINFO_MSG, Client_ID(Client),
 180              Client_ID(Client_ThisServer()), PACKAGE_VERSION, USERMODES,
 181              CHANMODES))
 182                 return false;
 183
 184         /* Features supported by this server (005 numeric, ISUPPORT),
 185          * see <http://www.irc.org/tech_docs/005.html> for details. */
 186         if (!IRC_Send_ISUPPORT(Client))
 187                 return DISCONNECTED;
 188
 189         if (!IRC_Send_LUSERS(Client))
 190                 return DISCONNECTED;
 191         if (!IRC_Show_MOTD(Client))
 192                 return DISCONNECTED;
 193
 194         /* Set default user modes */
 195         if (Conf_DefaultUserModes[0]) {
 196                 snprintf(modes, sizeof(modes), "+%s", Conf_DefaultUserModes);
 197                 Req.prefix = Client_ThisServer();
 198                 Req.command = "MODE";
 199                 Req.argc = 2;
 200                 Req.argv[0] = Client_ID(Client);
 201                 Req.argv[1] = modes;
 202                 IRC_MODE(Client, &Req);
 203         } else
 204                 IRC_SetPenalty(Client, 1);
 205
 206         return CONNECTED;
 207 }
 208
 209 #ifdef PAM
 210
 211 /**
 212  * Read result of the authenticator sub-process from pipe
 213  *
 214  * @param r_fd          File descriptor of the pipe.
 215  * @param events        (ignored IO specification)
 216  */
 217 static void
 218 cb_Read_Auth_Result(int r_fd, UNUSED short events)
 219 {
 220         char user[CLIENT_USER_LEN], *ptr;
 221         CONN_ID conn;
 222         CLIENT *client;
 223         int result;
 224         size_t len;
 225         PROC_STAT *proc;
 226
 227         LogDebug("Auth: Got callback on fd %d, events %d", r_fd, events);
 228         conn = Conn_GetFromProc(r_fd);
 229         if (conn == NONE) {
 230                 /* Ops, none found? Probably the connection has already
 231                  * been closed!? We'll ignore that ... */
 232                 io_close(r_fd);
 233                 LogDebug("Auth: Got callback for unknown connection!?");
 234                 return;
 235         }
 236         proc = Conn_GetProcStat(conn);
 237         client = Conn_GetClient(conn);
 238
 239         /* Read result from pipe */
 240         len = Proc_Read(proc, &result, sizeof(result));
 241         Proc_Close(proc);
 242         if (len == 0)
 243                 return;
 244
 245         if (len != sizeof(result)) {
 246                 Log(LOG_CRIT, "Auth: Got malformed result!");
 247                 Client_Reject(client, "Internal error", false);
 248                 return;
 249         }
 250
 251         if (result == true) {
 252                 /* Authentication succeeded, now set the correct user name
 253                  * supplied by the client (without prepended '~' for exmaple),
 254                  * but cut it at the first '@' character: */
 255                 strlcpy(user, Client_OrigUser(client), sizeof(user));
 256                 ptr = strchr(user, '@');
 257                 if (ptr)
 258                         *ptr = '\0';
 259                 Client_SetUser(client, user, true);
 260                 (void)Login_User_PostAuth(client);
 261         } else
 262                 Client_Reject(client, "Bad password", false);
 263 }
 264
 265 #endif
 266
 267 /* -eof- */