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root/svn/ircd-hybrid/trunk/modules/m_cap.c
Revision: 3565
Committed: Fri May 16 14:47:42 2014 UTC (11 years, 3 months ago) by michael
Content type: text/x-csrc
File size: 12614 byte(s)
Log Message:
- Style corrections

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# Content
1 /*
2 * ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3 *
4 * Copyright (c) 2004 Kevin L. Mitchell <klmitch@mit.edu>
5 * Copyright (c) 2006-2014 ircd-hybrid development team
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 * USA
21 */
22
23 /*! \file m_cap.c
24 * \brief Includes required functions for processing the CAP command.
25 * \version $Id$
26 */
27
28 #include "stdinc.h"
29 #include "client.h"
30 #include "hash.h"
31 #include "ircd.h"
32 #include "numeric.h"
33 #include "user.h"
34 #include "send.h"
35 #include "parse.h"
36 #include "modules.h"
37 #include "irc_string.h"
38
39
40 #define CAPFL_HIDDEN 0x0001 /**< Do not advertize this capability */
41 #define CAPFL_PROHIBIT 0x0002 /**< Client may not set this capability */
42 #define CAPFL_PROTO 0x0004 /**< Cap must be acknowledged by client */
43 #define CAPFL_STICKY 0x0008 /**< Cap may not be cleared once set */
44
45 typedef int (*bqcmp)(const void *, const void *);
46
47 static struct capabilities
48 {
49 unsigned int cap;
50 unsigned int flags;
51 const char *name;
52 size_t namelen;
53 } capab_list[] = {
54 #define _CAP(cap, flags, name) \
55 { (cap), (flags), (name), sizeof(name) - 1 }
56 _CAP(CAP_UHNAMES, 0, "userhost-in-names"),
57 _CAP(CAP_MULTI_PREFIX, 0, "multi-prefix"),
58 _CAP(CAP_AWAY_NOTIFY, 0, "away-notify")
59 #undef _CAP
60 };
61
62 #define CAPAB_LIST_LEN (sizeof(capab_list) / sizeof(struct capabilities))
63
64 static int
65 capab_sort(const struct capabilities *cap1, const struct capabilities *cap2)
66 {
67 return strcasecmp(cap1->name, cap2->name);
68 }
69
70 static int
71 capab_search(const char *key, const struct capabilities *cap)
72 {
73 const char *rb = cap->name;
74
75 while (ToLower(*key) == ToLower(*rb)) /* Walk equivalent part of strings */
76 if (*key++ == '\0') /* Hit the end, all right... */
77 return 0;
78 else /* OK, let's move on... */
79 rb++;
80
81 /*
82 * If the character they differ on happens to be a space, and it happens
83 * to be the same length as the capability name, then we've found a
84 * match; otherwise, return the difference of the two.
85 */
86 return (IsSpace(*key) && *rb == '\0') ? 0 : (ToLower(*key) - ToLower(*rb));
87 }
88
89 static struct capabilities *
90 find_cap(const char **caplist_p, int *neg_p)
91 {
92 static int inited = 0;
93 const char *caplist = *caplist_p;
94 struct capabilities *cap = NULL;
95
96 *neg_p = 0; /* Clear negative flag... */
97
98 if (!inited)
99 {
100 /* First, let's sort the array... */
101 qsort(capab_list, CAPAB_LIST_LEN, sizeof(struct capabilities), (bqcmp)capab_sort);
102 ++inited;
103 }
104
105 /* Next, find first non-whitespace character... */
106 while (*caplist && IsSpace(*caplist))
107 ++caplist;
108
109 /* We are now at the beginning of an element of the list; is it negative? */
110 if (*caplist == '-')
111 {
112 ++caplist; /* Yes; step past the flag... */
113 *neg_p = 1; /* Remember that it is negative... */
114 }
115
116 /* OK, now see if we can look up the capability... */
117 if (*caplist)
118 {
119 if (!(cap = bsearch(caplist, capab_list, CAPAB_LIST_LEN,
120 sizeof(struct capabilities),
121 (bqcmp)capab_search)))
122 {
123 /* Couldn't find the capability; advance to first whitespace character */
124 while (*caplist && !IsSpace(*caplist))
125 ++caplist;
126 }
127 else
128 caplist += cap->namelen; /* Advance to end of capability name */
129
130 /* Strip trailing spaces */
131 while (*caplist && IsSpace(*caplist))
132 ++caplist;
133 }
134
135 assert(caplist != *caplist_p || !*caplist); /* We *must* advance */
136
137 /* Move ahead in capability list string--or zero pointer if we hit end */
138 *caplist_p = *caplist ? caplist : NULL;
139
140 return cap; /* And return the capability (if any) */
141 }
142
143 /** Send a CAP \a subcmd list of capability changes to \a source_p.
144 * If more than one line is necessary, each line before the last has
145 * an added "*" parameter before that line's capability list.
146 * @param[in] source_p Client receiving capability list.
147 * @param[in] set Capabilities to show as set (with ack and sticky modifiers).
148 * @param[in] rem Capabalities to show as removed (with no other modifier).
149 * @param[in] subcmd Name of capability subcommand.
150 */
151 static int
152 send_caplist(struct Client *source_p, unsigned int set,
153 unsigned int rem, const char *subcmd)
154 {
155 char capbuf[IRCD_BUFSIZE] = "", pfx[16];
156 char cmdbuf[IRCD_BUFSIZE] = "";
157 unsigned int i, loc, len, flags, pfx_len, clen;
158
159 /* Set up the buffer for the final LS message... */
160 clen = snprintf(cmdbuf, sizeof(capbuf), ":%s CAP %s %s ", me.name,
161 source_p->name[0] ? source_p->name : "*", subcmd);
162
163 for (i = 0, loc = 0; i < CAPAB_LIST_LEN; ++i)
164 {
165 flags = capab_list[i].flags;
166
167 /*
168 * This is a little bit subtle, but just involves applying de
169 * Morgan's laws to the obvious check: We must display the
170 * capability if (and only if) it is set in \a rem or \a set, or
171 * if both are null and the capability is hidden.
172 */
173 if (!(rem && (rem & capab_list[i].cap)) &&
174 !(set && (set & capab_list[i].cap)) &&
175 (rem || set || (flags & CAPFL_HIDDEN)))
176 continue;
177
178 /* Build the prefix (space separator and any modifiers needed). */
179 pfx_len = 0;
180
181 if (loc)
182 pfx[pfx_len++] = ' ';
183 if (rem && (rem & capab_list[i].cap))
184 pfx[pfx_len++] = '-';
185 else
186 {
187 if (flags & CAPFL_PROTO)
188 pfx[pfx_len++] = '~';
189 if (flags & CAPFL_STICKY)
190 pfx[pfx_len++] = '=';
191 }
192
193 pfx[pfx_len] = '\0';
194
195 len = capab_list[i].namelen + pfx_len; /* How much we'd add... */
196
197 if (sizeof(capbuf) < (clen + loc + len + 15))
198 {
199 /* Would add too much; must flush */
200 sendto_one(source_p, "%s* :%s", cmdbuf, capbuf);
201 capbuf[(loc = 0)] = '\0'; /* Re-terminate the buffer... */
202 }
203
204 loc += snprintf(capbuf + loc, sizeof(capbuf) - loc,
205 "%s%s", pfx, capab_list[i].name);
206 }
207
208 sendto_one(source_p, "%s:%s", cmdbuf, capbuf);
209
210 return 0; /* Convenience return */
211 }
212
213 static int
214 cap_ls(struct Client *source_p, const char *caplist)
215 {
216 if (IsUnknown(source_p)) /* Registration hasn't completed; suspend it... */
217 source_p->localClient->registration |= REG_NEED_CAP;
218
219 return send_caplist(source_p, 0, 0, "LS"); /* Send list of capabilities */
220 }
221
222 static int
223 cap_req(struct Client *source_p, const char *caplist)
224 {
225 const char *cl = caplist;
226 struct capabilities *cap = NULL;
227 unsigned int set = 0, rem = 0;
228 unsigned int cs = source_p->localClient->cap_client; /* capability set */
229 unsigned int as = source_p->localClient->cap_active; /* active set */
230 int neg = 0;
231
232 if (IsUnknown(source_p)) /* Registration hasn't completed; suspend it... */
233 source_p->localClient->registration |= REG_NEED_CAP;
234
235 while (cl) { /* Walk through the capabilities list... */
236 if (!(cap = find_cap(&cl, &neg)) /* Look up capability... */
237 || (!neg && (cap->flags & CAPFL_PROHIBIT)) /* Is it prohibited? */
238 || (neg && (cap->flags & CAPFL_STICKY))) { /* Is it sticky? */
239 sendto_one(source_p, ":%s CAP %s NAK :%s", me.name,
240 source_p->name[0] ? source_p->name : "*", caplist);
241 return 0; /* Can't complete requested op... */
242 }
243
244 if (neg)
245 {
246 /* Set or clear the capability... */
247 rem |= cap->cap;
248 set &= ~cap->cap;
249 cs &= ~cap->cap;
250
251 if (!(cap->flags & CAPFL_PROTO))
252 as &= ~cap->cap;
253 }
254 else
255 {
256 rem &= ~cap->cap;
257 set |= cap->cap;
258 cs |= cap->cap;
259
260 if (!(cap->flags & CAPFL_PROTO))
261 as |= cap->cap;
262 }
263 }
264
265 /* Notify client of accepted changes and copy over results. */
266 send_caplist(source_p, set, rem, "ACK");
267
268 source_p->localClient->cap_client = cs;
269 source_p->localClient->cap_active = as;
270
271 return 0;
272 }
273
274 static int
275 cap_ack(struct Client *source_p, const char *caplist)
276 {
277 const char *cl = caplist;
278 struct capabilities *cap = NULL;
279 int neg = 0;
280
281 /*
282 * Coming from the client, this generally indicates that the client
283 * is using a new backwards-incompatible protocol feature. As such,
284 * it does not require further response from the server.
285 */
286 while (cl)
287 {
288 /* Walk through the capabilities list... */
289 if (!(cap = find_cap(&cl, &neg)) || /* Look up capability... */
290 (neg ? (source_p->localClient->cap_active & cap->cap) :
291 !(source_p->localClient->cap_active & cap->cap))) /* uh... */
292 continue;
293
294 if (neg) /* Set or clear the active capability... */
295 source_p->localClient->cap_active &= ~cap->cap;
296 else
297 source_p->localClient->cap_active |= cap->cap;
298 }
299
300 return 0;
301 }
302
303 static int
304 cap_clear(struct Client *source_p, const char *caplist)
305 {
306 struct capabilities *cap = NULL;
307 unsigned int cleared = 0;
308
309 for (unsigned int ii = 0; ii < CAPAB_LIST_LEN; ++ii)
310 {
311 cap = &capab_list[ii];
312
313 /* Only clear active non-sticky capabilities. */
314 if (!(source_p->localClient->cap_active & cap->cap) || (cap->flags & CAPFL_STICKY))
315 continue;
316
317 cleared |= cap->cap;
318 source_p->localClient->cap_client &= ~cap->cap;
319
320 if (!(cap->flags & CAPFL_PROTO))
321 source_p->localClient->cap_active &= ~cap->cap;
322 }
323
324 return send_caplist(source_p, 0, cleared, "ACK");
325 }
326
327 static int
328 cap_end(struct Client *source_p, const char *caplist)
329 {
330 if (!IsUnknown(source_p)) /* Registration has completed... */
331 return 0; /* So just ignore the message... */
332
333 /* Capability negotiation is now done... */
334 source_p->localClient->registration &= ~REG_NEED_CAP;
335
336 /* If client is now done... */
337 if (!source_p->localClient->registration)
338 {
339 register_local_user(source_p);
340 return 0;
341 }
342
343 return 0; /* Can't do registration yet... */
344 }
345
346 static int
347 cap_list(struct Client *source_p, const char *caplist)
348 {
349 /* Send the list of the client's capabilities */
350 return send_caplist(source_p, source_p->localClient->cap_client, 0, "LIST");
351 }
352
353 static struct subcmd
354 {
355 const char *cmd;
356 int (*proc)(struct Client *, const char *);
357 } cmdlist[] = {
358 { "ACK", cap_ack },
359 { "CLEAR", cap_clear },
360 { "END", cap_end },
361 { "LIST", cap_list },
362 { "LS", cap_ls },
363 { "NAK", NULL },
364 { "REQ", cap_req }
365 };
366
367 static int
368 subcmd_search(const char *cmd, const struct subcmd *elem)
369 {
370 return strcasecmp(cmd, elem->cmd);
371 }
372
373 /*! \brief CAP command handler
374 *
375 * \param source_p Pointer to allocated Client struct from which the message
376 * originally comes from. This can be a local or remote client.
377 * \param parc Integer holding the number of supplied arguments.
378 * \param parv Argument vector where parv[0] .. parv[parc-1] are non-NULL
379 * pointers.
380 * \note Valid arguments for this command are:
381 * - parv[0] = command
382 * - parv[1] = CAP subcommand
383 * - parv[2] = space-separated list of capabilities
384 */
385 static int
386 m_cap(struct Client *source_p, int parc, char *parv[])
387 {
388 const char *subcmd = NULL, *caplist = NULL;
389 struct subcmd *cmd = NULL;
390
391 if (EmptyString(parv[1])) /* A subcommand is required */
392 return 0;
393
394 subcmd = parv[1];
395
396 if (parc > 2) /* A capability list was provided */
397 caplist = parv[2];
398
399 /* Find the subcommand handler */
400 if (!(cmd = bsearch(subcmd, cmdlist,
401 sizeof(cmdlist) / sizeof(struct subcmd),
402 sizeof(struct subcmd), (bqcmp)subcmd_search)))
403 {
404 sendto_one_numeric(source_p, &me, ERR_INVALIDCAPCMD, subcmd);
405 return 0;
406 }
407
408 /* Then execute it... */
409 if (cmd->proc)
410 (cmd->proc)(source_p, caplist);
411 return 0;
412 }
413
414 static struct Message cap_msgtab =
415 {
416 "CAP", 0, 0, 2, MAXPARA, MFLG_SLOW, 0,
417 { m_cap, m_cap, m_ignore, m_ignore, m_cap, m_ignore }
418 };
419
420 static void
421 module_init(void)
422 {
423 mod_add_cmd(&cap_msgtab);
424 }
425
426 static void
427 module_exit(void)
428 {
429 mod_del_cmd(&cap_msgtab);
430 }
431
432 struct module module_entry =
433 {
434 .node = { NULL, NULL, NULL },
435 .name = NULL,
436 .version = "$Revision$",
437 .handle = NULL,
438 .modinit = module_init,
439 .modexit = module_exit,
440 .flags = 0
441 };

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