1 /*
2  *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3  *
4  *  Copyright (c) 1997-2021 ircd-hybrid development team
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19  *  USA
20  */
21 
22 /*! \file client.h
23  * \brief Header including structures, macros and prototypes for client handling
24  * \version $Id: client.h 10005 2021-06-28 12:10:15Z michael $
25  */
26 
27 
28 #ifndef INCLUDED_client_h
29 #define INCLUDED_client_h
30 
31 #include "list.h"
32 #include "fdlist.h"
33 #include "ircd_defs.h"
34 #include "dbuf.h"
35 #include "auth.h"
36 
37 
38 /*
39  * status macros.
40  */
41 enum
42 {
43   STAT_CONNECTING = 1,
44   STAT_HANDSHAKE,
45   STAT_ME,
46   STAT_UNKNOWN,
47   STAT_SERVER,
48   STAT_CLIENT
49 };
50 
51 enum
52 {
53   REG_NEED_USER = 1 << 0,  /**< User must send USER command */
54   REG_NEED_NICK = 1 << 1,  /**< User must send NICK command */
55   REG_NEED_CAP  = 1 << 2,  /**< In middle of CAP negotiations */
56   REG_INIT      = REG_NEED_USER | REG_NEED_NICK
57 };
58 
59 #define ID_or_name(x,client_p)  ((IsServer(client_p->from) && (x)->id[0]) ? (x)->id : (x)->name)
60 
61 #define IsConnecting(x)         ((x)->status == STAT_CONNECTING)
62 #define IsHandshake(x)          ((x)->status == STAT_HANDSHAKE)
63 #define IsMe(x)                 ((x)->status == STAT_ME)
64 #define IsUnknown(x)            ((x)->status == STAT_UNKNOWN)
65 #define IsServer(x)             ((x)->status == STAT_SERVER)
66 #define IsClient(x)             ((x)->status == STAT_CLIENT)
67 
68 #define SetConnecting(x)        {(x)->status = STAT_CONNECTING; \
69                                  (x)->handler = UNREGISTERED_HANDLER; }
70 
71 #define SetHandshake(x)         {(x)->status = STAT_HANDSHAKE; \
72                                  (x)->handler = UNREGISTERED_HANDLER; }
73 
74 #define SetMe(x)                {(x)->status = STAT_ME; \
75                                  (x)->handler = UNREGISTERED_HANDLER; }
76 
77 #define SetUnknown(x)           {(x)->status = STAT_UNKNOWN; \
78                                  (x)->handler = UNREGISTERED_HANDLER; }
79 
80 #define SetServer(x)            {(x)->status = STAT_SERVER; \
81                                  (x)->handler = SERVER_HANDLER; }
82 
83 #define SetClient(x)            {(x)->status = STAT_CLIENT; \
84                                  (x)->handler = CLIENT_HANDLER; }
85 
86 #define MyConnect(x)            ((x)->connection != NULL)
87 #define MyClient(x)             (MyConnect(x) && IsClient(x))
88 
89 /*
90  * ts stuff
91  */
92 enum
93 {
94   TS_CURRENT = 6,  /**< Current TS protocol version */
95   TS_MINIMUM = 6,  /**< Minimum supported TS protocol version */
96 };
97 
98 enum
99 {
100   CAP_MULTI_PREFIX   = 1 << 0,  /**< ircv3.1 multi-prefix client capability */
101   CAP_AWAY_NOTIFY    = 1 << 1,  /**< ircv3.1 away-notify client capability */
102   CAP_UHNAMES        = 1 << 2,  /**< ircv3.2 userhost-in-names client capability */
103   CAP_EXTENDED_JOIN  = 1 << 3,  /**< ircv3.1 extended-join client capability */
104   CAP_ACCOUNT_NOTIFY = 1 << 4,  /**< ircv3.1 account-notify client capability */
105   CAP_INVITE_NOTIFY  = 1 << 5,  /**< ircv3.2 invite-notify client capability */
106   CAP_CHGHOST        = 1 << 6,  /**< ircv3.2 chghost client capability */
107   CAP_CAP_NOTIFY     = 1 << 7,  /**< ircv3 CAP LS 302 cap-notify client capability */
108 };
109 
110 #define HasCap(x, y) ((x)->connection->cap & (y))
111 
112 
113 /* housekeeping flags */
114 enum
115 {
116   FLAGS_PINGSENT      = 1 <<  0,  /**< Unreplied ping sent */
117   FLAGS_DEADSOCKET    = 1 <<  1,  /**< Local socket is dead--Exiting soon */
118   FLAGS_KILLED        = 1 <<  2,  /**< Prevents "QUIT" from being sent for this */
119   FLAGS_CLOSING       = 1 <<  3,  /**< Set when closing to suppress errors */
120   FLAGS_GOTID         = 1 <<  4,  /**< Successful ident lookup achieved */
121   FLAGS_SENDQEX       = 1 <<  5,  /**< Sendq exceeded */
122   FLAGS_IPHASH        = 1 <<  6,  /**< Iphashed this client */
123   FLAGS_MARK          = 1 <<  7,  /**< Marked client */
124   FLAGS_CANFLOOD      = 1 <<  8,  /**< Client has the ability to flood */
125   FLAGS_EXEMPTKLINE   = 1 <<  9,  /**< Client is exempt from k-lines */
126   FLAGS_NOLIMIT       = 1 << 10,  /**< Client is exempt from limits */
127   FLAGS_PING_COOKIE   = 1 << 11,  /**< PING Cookie */
128   FLAGS_FLOODDONE     = 1 << 12,  /**< Flood grace period has been ended. */
129   FLAGS_EOB           = 1 << 13,  /**< Server has sent us an EOB */
130   FLAGS_HIDDEN        = 1 << 14,  /**< A hidden server. Not shown in /links */
131   FLAGS_BLOCKED       = 1 << 15,  /**< Must wait for COMM_SELECT_WRITE */
132   FLAGS_EXEMPTRESV    = 1 << 16,  /**< Client is exempt from RESV */
133   FLAGS_GOTUSER       = 1 << 17,  /**< If we received a USER command */
134   FLAGS_FINISHED_AUTH = 1 << 18,  /**< Client has been released from auth */
135   FLAGS_FLOOD_NOTICED = 1 << 19,  /**< Notice to opers about this flooder has been sent */
136   FLAGS_SERVICE       = 1 << 20,  /**< Client/server is a network service */
137   FLAGS_TLS           = 1 << 21,  /**< User is connected via TLS (Transport Layer Security) */
138   FLAGS_SQUIT         = 1 << 22,
139   FLAGS_EXEMPTXLINE   = 1 << 23,  /**< Client is exempt from x-lines */
140   FLAGS_CAP302        = 1 << 24  /**< Client supports the IRCv3 CAP 302 extension */
141 };
142 
143 #define HasFlag(x, y) ((x)->flags &   (y))
144 #define AddFlag(x, y) ((x)->flags |=  (y))
145 #define DelFlag(x, y) ((x)->flags &= ~(y))
146 
147 
148 /* umodes, settable flags */
149 enum
150 {
151   UMODE_SERVNOTICE   = 1 <<  0,  /**< Server notices such as kill */
152   UMODE_CCONN        = 1 <<  1,  /**< Can see client connection notices */
153   UMODE_REJ          = 1 <<  2,  /**< Bot Rejections */
154   UMODE_SKILL        = 1 <<  3,  /**< Server Killed */
155   UMODE_FLOOD        = 1 <<  4,  /**< Flooding/spambot notices */
156   UMODE_SPY          = 1 <<  5,  /**< See STATS / LINKS */
157   UMODE_DEBUG        = 1 <<  6,  /**< 'debugging' info */
158   UMODE_NCHANGE      = 1 <<  7,  /**< Nick change notice */
159   UMODE_WALLOP       = 1 <<  8,  /**< Send wallops to them */
160   UMODE_INVISIBLE    = 1 <<  9,  /**< Makes user invisible */
161   UMODE_EXTERNAL     = 1 << 10,  /**< Show servers introduced and splitting */
162   UMODE_CALLERID     = 1 << 11,  /**< Block unless caller id's */
163   UMODE_SOFTCALLERID = 1 << 12,  /**< Block unless on common channel */
164   UMODE_LOCOPS       = 1 << 13,  /**< Can see LOCOPS messages */
165   UMODE_DEAF         = 1 << 14,  /**< Don't receive channel messages */
166   UMODE_REGISTERED   = 1 << 15,  /**< User has identified for that nick. */
167   UMODE_REGONLY      = 1 << 16,  /**< Only registered nicks may PM */
168   UMODE_HIDDEN       = 1 << 17,  /**< IRC operator status is hidden */
169   UMODE_OPER         = 1 << 18,  /**< IRC operator */
170   UMODE_ADMIN        = 1 << 19,  /**< Admin on server */
171   UMODE_FARCONNECT   = 1 << 20,  /**< Can see remote client connects/exits */
172   UMODE_SECURE       = 1 << 21,  /**< User is connected via TLS */
173   UMODE_WEBIRC       = 1 << 22,  /**< User connected via a webirc gateway */
174   UMODE_HIDEIDLE     = 1 << 23,  /**< Hides idle and signon time in WHOIS */
175   UMODE_HIDECHANS    = 1 << 24,  /**< Hides channel list in WHOIS */
176   UMODE_EXPIRATION   = 1 << 25,  /**< Receives *LINE expiration notices */
177   UMODE_BOT          = 1 << 26  /**< Client is marked as a bot in WHOIS and WHO */
178 };
179 
180 #define HasUMode(x, y) ((x)->umodes &   (y))
181 #define AddUMode(x, y) ((x)->umodes |=  (y))
182 #define DelUMode(x, y) ((x)->umodes &= ~(y))
183 
184 
185 /** irc-operator privilege flags */
186 enum
187 {
188   OPER_FLAG_ADMIN          = 1 <<  0,  /**< Oper can set user mode +a */
189   OPER_FLAG_CLOSE          = 1 <<  1,  /**< Oper can use CLOSE command */
190   OPER_FLAG_CONNECT        = 1 <<  2,  /**< Oper can do local CONNECT */
191   OPER_FLAG_CONNECT_REMOTE = 1 <<  3,  /**< Oper can do remote CONNECT */
192   OPER_FLAG_DIE            = 1 <<  4,  /**< Oper can use DIE command */
193   OPER_FLAG_DLINE          = 1 <<  5,  /**< Oper can use DLINE command */
194   OPER_FLAG_GLOBOPS        = 1 <<  6,  /**< Oper can use GLOBOPS command */
195   OPER_FLAG_JOIN_RESV      = 1 <<  7,  /**< Oper can use JOIN on resv {} channels */
196   OPER_FLAG_KILL           = 1 <<  8,  /**< Oper can KILL local users */
197   OPER_FLAG_KILL_REMOTE    = 1 <<  9,  /**< Oper can KILL remote users */
198   OPER_FLAG_KLINE          = 1 << 10,  /**< Oper can use KLINE command */
199   OPER_FLAG_LOCOPS         = 1 << 11,  /**< Oper can use LOCOPS command */
200   OPER_FLAG_MODULE         = 1 << 12,  /**< Oper can use MODULE command */
201   OPER_FLAG_NICK_RESV      = 1 << 13,  /**< Oper can use NICK on resv {} nicks */
202   OPER_FLAG_OPME           = 1 << 14,  /**< Oper can use OPME command */
203   OPER_FLAG_REHASH         = 1 << 15,  /**< Oper can use REHASH command */
204   OPER_FLAG_REHASH_REMOTE  = 1 << 16,  /**< Oper can do remote REHASH command */
205   OPER_FLAG_REMOTEBAN      = 1 << 17,  /**< Oper can set remote bans */
206   OPER_FLAG_RESTART        = 1 << 18,  /**< Oper can use RESTART command */
207   OPER_FLAG_RESV           = 1 << 19,  /**< Oper can use RESV command */
208   OPER_FLAG_SET            = 1 << 20,  /**< Oper can use SET command */
209   OPER_FLAG_SQUIT          = 1 << 21,  /**< Oper can do local SQUIT */
210   OPER_FLAG_SQUIT_REMOTE   = 1 << 22,  /**< Oper can do remote SQUIT */
211   OPER_FLAG_UNDLINE        = 1 << 23,  /**< Oper can use UNDLINE command */
212   OPER_FLAG_UNKLINE        = 1 << 24,  /**< Oper can use UNKLINE command */
213   OPER_FLAG_UNRESV         = 1 << 25,  /**< Oper can use UNRESV command */
214   OPER_FLAG_UNXLINE        = 1 << 26,  /**< Oper can use UNXLINE command */
215   OPER_FLAG_WALLOPS        = 1 << 27,  /**< Oper can use WALLOPS command */
216   OPER_FLAG_XLINE          = 1 << 28   /**< Oper can use XLINE command */
217 };
218 
219 #define HasOFlag(x, y) ((x)->connection->operflags &   (y))
220 #define AddOFlag(x, y) ((x)->connection->operflags |=  (y))
221 #define DelOFlag(x, y) ((x)->connection->operflags &= ~(y))
222 #define ClrOFlag(x)    ((x)->connection->operflags = 0)
223 
224 
225 
226 /* flags macros. */
227 #define IsDead(x)               ((x)->flags & FLAGS_DEADSOCKET)
228 #define SetDead(x)              ((x)->flags |= FLAGS_DEADSOCKET)
229 #define IsDefunct(x)            ((x)->flags & (FLAGS_DEADSOCKET|FLAGS_CLOSING|FLAGS_KILLED))
230 
231 /* oper flags */
232 #define SetOper(x)              {(x)->umodes |= UMODE_OPER; \
233                                  if (MyClient((x))) (x)->handler = OPER_HANDLER;}
234 
235 #define ClearOper(x)            {(x)->umodes &= ~(UMODE_OPER|UMODE_ADMIN); \
236                                  if (MyClient((x))) \
237                                   (x)->handler = CLIENT_HANDLER; }
238 
239 #define IsHidden(x)             ((x)->flags &  FLAGS_HIDDEN)
240 
241 
242 /*! \brief server ban types */
243 enum
244 {
245   CLIENT_BAN_KLINE,
246   CLIENT_BAN_DLINE,
247   CLIENT_BAN_XLINE
248 };
249 
250 /*! \brief addr_mask_type enumeration */
251 enum addr_mask_type
252 {
253   HIDE_IP,  /**< IP is hidden. Resolved hostname is shown instead */
254   SHOW_IP,  /**< IP is shown. No parts of it are hidden or masked */
255   MASK_IP   /**< IP is masked. 255.255.255.255 is shown instead */
256 };
257 
258 /*! \brief Server structure */
259 struct Server
260 {
261   dlink_list server_list;  /**< Servers on this server */
262   dlink_list client_list;  /**< Clients on this server */
263   char by[NICKLEN + 1];  /**< Who activated this connection */
264 };
265 
266 /*! \brief ListTask structure */
267 struct ListTask
268 {
269   dlink_node node;  /**< Embedded list node used to link into listing_client_list */
270   dlink_list show_mask;  /**< Channels to show */
271   dlink_list hide_mask;  /**< Channels to hide */
272 
273   unsigned int hash_index;  /**< The hash bucket we are currently in */
274   unsigned int users_min;
275   unsigned int users_max;
276   unsigned int created_min;  /**< Real time */
277   unsigned int created_max;  /**< Real time */
278   unsigned int topicts_min;  /**< Real time */
279   unsigned int topicts_max;  /**< Real time */
280   char topic[TOPICLEN + 1];
281 };
282 
283 /*! \brief Connection structure
284  *
285  * Allocated only for local clients, that are directly connected
286  * to \b this server with a socket.
287  */
288 struct Connection
289 {
290   dlink_node lclient_node;
291 
292   unsigned int registration;
293   unsigned int cap;  /**< Client CAP bit-field */
294   unsigned int capab;  /**< Server CAPAB bit field */
295 
296   unsigned int operflags;  /**< IRC Operator privilege flags */
297   unsigned int random_ping;  /**< Holding a 32bit value used for PING cookies */
298 
299   uintmax_t serial;  /**< Used to enforce 1 send per nick */
300   uintmax_t last_data;  /**< Last time data read from socket; monotonic time */
301   uintmax_t last_ping;  /**< Last time data read from socket; currently this is a copy of last_data
302                              which can be modified by check_pings_list; monotonic time */
303   uintmax_t created_real;  /**< Time client was created; real time */
304   uintmax_t created_monotonic;  /**< Time client was created; monotonic time */
305   uintmax_t last_caller_id_time;  /**< Monotonic time */
306   uintmax_t first_received_message_time;  /**< Monotonic time */
307   uintmax_t last_privmsg;  /**< Last time we got a PRIVMSG; monotonic time */
308   uintmax_t last_join_time;  /**< When this client last joined a channel; monotonic time */
309   uintmax_t last_leave_time;  /**< When this client last left a channel; monotonic time */
310 
311   unsigned int join_leave_count;  /**< Count of JOIN/LEAVE in less than MIN_JOIN_LEAVE_TIME seconds */
312   unsigned int oper_warn_count_down;  /**< Warn opers of this possible spambot every time this gets to 0 */
313   unsigned int received_number_of_privmsgs;
314 
315   struct ListTask  *list_task;
316 
317   struct dbuf_queue buf_sendq;
318   struct dbuf_queue buf_recvq;
319 
320   struct
321   {
322     unsigned int messages;  /**< Statistics: protocol messages sent/received */
323     uintmax_t bytes;  /**< Statistics: total bytes sent/received */
324   } recv, send;
325 
326   struct
327   {
328     unsigned int count;  /**< How many AWAY/INVITE/KNOCK/NICK requests client has sent */
329     uintmax_t last_attempt;  /**< Last time the AWAY/INVITE/KNOCK/NICK request was issued; monotonic time */
330   } away, invite, knock, nick;
331 
332   struct AuthRequest *auth;
333   struct Listener *listener;  /**< Listener accepted from */
334   dlink_list acceptlist;  /**< Clients I'll allow to talk to me */
335   dlink_list monitors;  /**< Chain of Monitor pointer blocks */
336   dlink_list confs;  /**< Configuration record associated */
337   dlink_list invited;  /**< Chain of invite pointer blocks */
338 
339   fde_t *fd;  /**< Pointer to fdlist.c:fd_table[] */
340 
341   /* Anti-flood stuff. We track how many messages were parsed and how
342    * many we were allowed in the current second, and apply a simple
343    * decay to avoid flooding.
344    *   -- adrian
345    */
346   int sent_parsed;  /**< How many messages we've parsed in this second */
347 
348   char *password;  /**< Password supplied by the client/server */
349 };
350 
351 /*! \brief Client structure */
352 struct Client
353 {
354   dlink_node node;
355   dlink_node lnode;  /**< Used for Server->servers/users */
356 
357   struct Connection *connection;  /**< Connection structure associated with this client */
358   struct Client *hnext;  /**< For client hash table lookups by name */
359   struct Client *idhnext;  /**< For SID hash table lookups by sid */
360   struct Server *serv;  /**< ...defined, if this is a server */
361   struct Client *servptr;  /**< Points to server this Client is on */
362   struct Client *from;  /**< == self, if Local Client, *NEVER* NULL! */
363 
364   uintmax_t tsinfo;  /**< Timestamp on this nick; real time */
365 
366   unsigned int flags;  /**< Client flags */
367   unsigned int umodes;  /**< User modes this client has set */
368   unsigned int hopcount;  /**< Number of servers to this 0 = local */
369   unsigned int status;  /**< Client type */
370   unsigned int handler;  /**< Handler index */
371 
372   dlink_list whowas_list;
373   dlink_list channel;  /**< Chain of channel pointer blocks */
374   dlink_list svstags;  /**< List of ServicesTag items */
375 
376   struct irc_ssaddr ip;  /**< Real IP address */
377 
378   char *tls_certfp;  /**< TLS certificate fingerprint */
379   char *tls_cipher;  /**< Exact copy of tls_get_cipher() */
380 
381   char away[AWAYLEN + 1];  /**< Client's AWAY message. Can be set/unset via AWAY command */
382   char name[HOSTLEN + 1];  /**< Unique name for a client nick or host */
383   char id[IDLEN + 1];  /**< Client ID, unique ID per client */
384   char account[ACCOUNTLEN + 1];  /**< Services account */
385 
386   /*
387    * client->username is the username from ident or the USER message,
388    * If the client is idented the USER message is ignored, otherwise
389    * the username part of the USER message is put here prefixed with a
390    * tilde depending on the auth{} block. Once a client has registered,
391    * this field should be considered read-only.
392    */
393   char username[USERLEN + 1];  /**< client's username */
394 
395   /*
396    * client->host contains the resolved name or ip address as a string
397    * for the user, it may be fiddled with for oper spoofing etc.
398    * once it's changed the *real* address goes away.
399    */
400   char host[HOSTLEN + 1];  /**< Client's hostname. Can be faked/spoofed */
401 
402   /*
403    * client->realhost contains the resolved name or ip address as a string
404    * for the user. Once a client has registered, this field should be
405    * considered read-only.
406    */
407   char realhost[HOSTLEN + 1];  /**< Client's real hostname */
408 
409 
410   /*
411    * client->info for unix clients will normally contain the info from the
412    * gcos field in /etc/passwd but anything can go here.
413    */
414   char info[REALLEN + 1];  /**< Free form additional client info */
415 
416   /*
417    * client->sockhost contains the ip address gotten from the socket as a
418    * string, this field should be considered read-only once the connection
419    * has been made. (set in s_bsd.c only)
420    */
421   char sockhost[HOSTIPLEN + 1];  /**< This is the host name from the socket ip address as string */
422 };
423 
424 
425 struct AcceptItem
426 {
427   dlink_node node;
428   char *nick;
429   char *user;
430   char *host;
431 };
432 
433 
434 extern struct Client me;
435 extern dlink_list listing_client_list;
436 extern dlink_list global_client_list;
437 extern dlink_list global_server_list;  /* global servers on the network */
438 extern dlink_list local_client_list;  /* local clients only ON this server */
439 extern dlink_list local_server_list;  /* local servers to this server ONLY */
440 extern dlink_list unknown_list;  /* unknown clients ON this server only */
441 extern dlink_list oper_list;  /* our opers, duplicated in local_client_list */
442 
443 extern bool accept_message(struct Client *, struct Client *);
444 extern unsigned int client_get_idle_time(const struct Client *, const struct Client *);
445 extern struct AcceptItem *accept_find(const char *, const char *, const char *, dlink_list *, int (*)(const char *, const char *));
446 extern void accept_del(struct AcceptItem *, dlink_list *);
447 extern void accept_clear_list(dlink_list *);
448 extern void exit_client(struct Client *, const char *);
449 extern void conf_try_ban(struct Client *, int, const char *);
450 extern void check_conf_klines(void);
451 extern void client_init(void);
452 extern void dead_link_on_write(struct Client *, int);
453 extern void dead_link_on_read(struct Client *, int);
454 extern void exit_aborted_clients(void);
455 extern void free_exited_clients(void);
456 extern struct Client *client_make(struct Client *);
457 extern struct Client *find_chasing(struct Client *, const char *);
458 extern struct Client *find_person(const struct Client *, const char *);
459 extern const char *client_get_name(const struct Client *, enum addr_mask_type);
460 #endif  /* INCLUDED_client_h */
461