trunk/modules/m_cap.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 2004 Kevin L. Mitchell <klmitch@mit.edu>
 *  Copyright (c) 2006-2018 ircd-hybrid development team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

/*! \file m_cap.c
 * \brief Includes required functions for processing the CAP command.
 * \version $Id$
 */

#include "stdinc.h"
#include "client.h"
#include "ircd.h"
#include "numeric.h"
#include "user.h"
#include "send.h"
#include "parse.h"
#include "modules.h"
#include "irc_string.h"


enum
{
  CAPFL_HIDDEN    = 1 << 0,  /**< Do not advertize this capability */
  CAPFL_PROHIBIT  = 1 << 1,  /**< Client may not set this capability */
  CAPFL_PROTO     = 1 << 2,  /**< Cap must be acknowledged by client */
  CAPFL_STICKY    = 1 << 3   /**< Cap may not be cleared once set */
};

typedef int (*bqcmp)(const void *, const void *);

static struct capabilities
{
  unsigned int cap;
  unsigned int flags;
  const char *name;
  size_t namelen;
} capab_list[] = {
#define _CAP(cap, flags, name)  \
    { (cap), (flags), (name), sizeof(name) - 1 }
  _CAP(CAP_UHNAMES, 0, "userhost-in-names"),
  _CAP(CAP_MULTI_PREFIX, 0, "multi-prefix"),
  _CAP(CAP_AWAY_NOTIFY, 0, "away-notify"),
  _CAP(CAP_EXTENDED_JOIN, 0, "extended-join"),
  _CAP(CAP_ACCOUNT_NOTIFY, 0, "account-notify"),
  _CAP(CAP_INVITE_NOTIFY, 0, "invite-notify"),
  _CAP(CAP_CHGHOST, 0, "chghost")
#undef _CAP
};

#define CAPAB_LIST_LEN  (sizeof(capab_list) / sizeof(struct capabilities))

static int
capab_sort(const struct capabilities *cap1, const struct capabilities *cap2)
{
  return strcasecmp(cap1->name, cap2->name);
}

static int
capab_search(const char *key, const struct capabilities *cap)
{
  const char *rb = cap->name;

  while (ToLower(*key) == ToLower(*rb))  /* Walk equivalent part of strings */
    if (*key++ == '\0')  /* Hit the end, all right... */
      return 0;
    else  /* OK, let's move on... */
      ++rb;

  /*
   * If the character they differ on happens to be a space, and it happens
   * to be the same length as the capability name, then we've found a
   * match; otherwise, return the difference of the two.
   */
  return (IsSpace(*key) && *rb == '\0') ? 0 : (ToLower(*key) - ToLower(*rb));
}

static struct capabilities *
find_cap(const char **caplist_p, int *neg_p)
{
  const char *caplist = *caplist_p;
  struct capabilities *cap = NULL;

  *neg_p = 0;  /* Clear negative flag... */

  /* Next, find first non-whitespace character... */
  while (*caplist && IsSpace(*caplist))
    ++caplist;

  /* We are now at the beginning of an element of the list; is it negative? */
  if (*caplist == '-')
  {
    ++caplist;  /* Yes; step past the flag... */
    *neg_p = 1;  /* Remember that it is negative... */
  }

  /* OK, now see if we can look up the capability... */
  if (*caplist)
  {
    if (!(cap = bsearch(caplist, capab_list, CAPAB_LIST_LEN,
                        sizeof(struct capabilities),
                        (bqcmp)capab_search)))
    {
      /* Couldn't find the capability; advance to first whitespace character */
      while (*caplist && !IsSpace(*caplist))
        ++caplist;
    }
    else
      caplist += cap->namelen;  /* Advance to end of capability name */

    /* Strip trailing spaces */
    while (*caplist && IsSpace(*caplist))
      ++caplist;
  }

  assert(caplist != *caplist_p || !*caplist);  /* We *must* advance */

  /* Move ahead in capability list string--or zero pointer if we hit end */
  *caplist_p = *caplist ? caplist : NULL;

  return cap;  /* And return the capability (if any) */
}

/** Send a CAP \a subcmd list of capability changes to \a source_p.
 * If more than one line is necessary, each line before the last has
 * an added "*" parameter before that line's capability list.
 * @param[in] source_p Client receiving capability list.
 * @param[in] set Capabilities to show as set (with ack and sticky modifiers).
 * @param[in] rem Capabalities to show as removed (with no other modifier).
 * @param[in] subcmd Name of capability subcommand.
 */
static int
send_caplist(struct Client *source_p,
             const unsigned int *const set,
             const unsigned int *const rem, const char *subcmd)
{
  char capbuf[IRCD_BUFSIZE] = "", pfx[16];
  char cmdbuf[IRCD_BUFSIZE] = "";
  unsigned int i, loc, len, pfx_len, clen;

  /* Set up the buffer for the final LS message... */
  clen = snprintf(cmdbuf, sizeof(capbuf), ":%s CAP %s %s ", me.name,
                  source_p->name[0] ? source_p->name : "*", subcmd);

  for (i = 0, loc = 0; i < CAPAB_LIST_LEN; ++i)
  {
    const struct capabilities *cap = &capab_list[i];

    /*
     * This is a little bit subtle, but just involves applying de
     * Morgan's laws to the obvious check: We must display the
     * capability if (and only if) it is set in \a rem or \a set, or
     * if both are null and the capability is hidden.
     */
    if (!(rem && (*rem & cap->cap)) &&
        !(set && (*set & cap->cap)) &&
         (rem || set || (cap->flags & CAPFL_HIDDEN)))
      continue;

    /* Build the prefix (space separator and any modifiers needed). */
    pfx_len = 0;

    if (loc)
      pfx[pfx_len++] = ' ';
    if (rem && (*rem & cap->cap))
      pfx[pfx_len++] = '-';
    else
    {
      if (cap->flags & CAPFL_PROTO)
        pfx[pfx_len++] = '~';
      if (cap->flags & CAPFL_STICKY)
        pfx[pfx_len++] = '=';
    }

    pfx[pfx_len] = '\0';

    len = cap->namelen + pfx_len;  /* How much we'd add... */

    if (sizeof(capbuf) < (clen + loc + len + 15))
    {
      /* Would add too much; must flush */
      sendto_one(source_p, "%s* :%s", cmdbuf, capbuf);
      capbuf[(loc = 0)] = '\0';  /* Re-terminate the buffer... */
    }

    loc += snprintf(capbuf + loc, sizeof(capbuf) - loc,
                    "%s%s", pfx, cap->name);
  }

  sendto_one(source_p, "%s:%s", cmdbuf, capbuf);

  return 0;  /* Convenience return */
}

static int
cap_ls(struct Client *source_p, const char *caplist)
{
  if (IsUnknown(source_p))  /* Registration hasn't completed; suspend it... */
    source_p->connection->registration |= REG_NEED_CAP;

  return send_caplist(source_p, NULL, NULL, "LS");  /* Send list of capabilities */
}

static int
cap_req(struct Client *source_p, const char *caplist)
{
  const char *cl = caplist;
  struct capabilities *cap = NULL;
  unsigned int set = 0, rem = 0;
  unsigned int cs = source_p->connection->cap_client; /* capability set */
  unsigned int as = source_p->connection->cap_active; /* active set */
  int neg = 0;

  if (IsUnknown(source_p))  /* Registration hasn't completed; suspend it... */
    source_p->connection->registration |= REG_NEED_CAP;

  while (cl) {  /* Walk through the capabilities list... */
    if (!(cap = find_cap(&cl, &neg))  /* Look up capability... */
        || (!neg && (cap->flags & CAPFL_PROHIBIT))  /* Is it prohibited? */
        || (neg && (cap->flags & CAPFL_STICKY))) {  /* Is it sticky? */
      sendto_one(source_p, ":%s CAP %s NAK :%s", me.name,
                 source_p->name[0] ? source_p->name : "*", caplist);
      return 0;  /* Can't complete requested op... */
    }

    if (neg)
    {
      /* Set or clear the capability... */
      rem |=  cap->cap;
      set &= ~cap->cap;
      cs  &= ~cap->cap;

      if (!(cap->flags & CAPFL_PROTO))
        as &= ~cap->cap;
    }
    else
    {
      rem &= ~cap->cap;
      set |=  cap->cap;
      cs  |=  cap->cap;

      if (!(cap->flags & CAPFL_PROTO))
        as |= cap->cap;
    }
  }

  /* Notify client of accepted changes and copy over results. */
  send_caplist(source_p, &set, &rem, "ACK");

  source_p->connection->cap_client = cs;
  source_p->connection->cap_active = as;

  return 0;
}

static int
cap_ack(struct Client *source_p, const char *caplist)
{
  const char *cl = caplist;
  struct capabilities *cap = NULL;
  int neg = 0;

  /*
   * Coming from the client, this generally indicates that the client
   * is using a new backwards-incompatible protocol feature. As such,
   * it does not require further response from the server.
   */
  while (cl)
  {
    /* Walk through the capabilities list... */
    if (!(cap = find_cap(&cl, &neg)) ||  /* Look up capability... */
        (neg ? (source_p->connection->cap_client & cap->cap) :
              !(source_p->connection->cap_client & cap->cap)))  /* uh... */
      continue;

    /* Set or clear the active capability... */
    if (neg)
    {
      if (cap->flags & CAPFL_STICKY)
        continue;  /* but don't clear sticky capabilities */

      source_p->connection->cap_active &= ~cap->cap;
    }
    else
    {
      if (cap->flags & CAPFL_PROHIBIT)
        continue;  /* and don't set prohibited ones */

      source_p->connection->cap_active |=  cap->cap;
    }
  }

  return 0;
}

static int
cap_clear(struct Client *source_p, const char *caplist)
{
  unsigned int cleared = 0;

  for (unsigned int ii = 0; ii < CAPAB_LIST_LEN; ++ii)
  {
    const struct capabilities *cap = &capab_list[ii];

    /* Only clear active non-sticky capabilities. */
    if (!(source_p->connection->cap_client & cap->cap) || (cap->flags & CAPFL_STICKY))
      continue;

    cleared |= cap->cap;
    source_p->connection->cap_client &= ~cap->cap;

    if (!(cap->flags & CAPFL_PROTO))
      source_p->connection->cap_active &= ~cap->cap;
  }

  return send_caplist(source_p, NULL, &cleared, "ACK");
}

static int
cap_end(struct Client *source_p, const char *caplist)
{
  if (!IsUnknown(source_p))  /* Registration has completed... */
    return 0;  /* So just ignore the message... */

  /* Capability negotiation is now done... */
  source_p->connection->registration &= ~REG_NEED_CAP;

  /* If client is now done... */
  if (!source_p->connection->registration)
  {
    register_local_user(source_p);
    return 0;
  }

  return 0;  /* Can't do registration yet... */
}

static int
cap_list(struct Client *source_p, const char *caplist)
{
  /* Send the list of the client's capabilities */
  return send_caplist(source_p, &source_p->connection->cap_client, NULL, "LIST");
}

static struct subcmd
{
  const char *cmd;
  int (*proc)(struct Client *, const char *);
} cmdlist[] = {
  { "ACK",   cap_ack   },
  { "CLEAR", cap_clear },
  { "END",   cap_end   },
  { "LIST",  cap_list  },
  { "LS",    cap_ls    },
  { "NAK",   NULL      },
  { "REQ",   cap_req   }
};

static int
subcmd_search(const char *cmd, const struct subcmd *elem)
{
  return strcasecmp(cmd, elem->cmd);
}

/*! \brief CAP command handler
 *
 * \param source_p Pointer to allocated Client struct from which the message
 *                 originally comes from.  This can be a local or remote client.
 * \param parc     Integer holding the number of supplied arguments.
 * \param parv     Argument vector where parv[0] .. parv[parc-1] are non-NULL
 *                 pointers.
 * \note Valid arguments for this command are:
 *      - parv[0] = command
 *      - parv[1] = CAP subcommand
 *      - parv[2] = space-separated list of capabilities
 */
static int
m_cap(struct Client *source_p, int parc, char *parv[])
{
  const char *subcmd = NULL, *caplist = NULL;
  struct subcmd *cmd = NULL;

  if (EmptyString(parv[1]))  /* A subcommand is required */
    return 0;

  subcmd = parv[1];

  if (parc > 2)  /* A capability list was provided */
    caplist = parv[2];

  /* Find the subcommand handler */
  if (!(cmd = bsearch(subcmd, cmdlist,
                      sizeof(cmdlist) / sizeof(struct subcmd),
                      sizeof(struct subcmd), (bqcmp)subcmd_search)))
  {
    sendto_one_numeric(source_p, &me, ERR_INVALIDCAPCMD, subcmd);
    return 0;
  }

  /* Then execute it... */
  if (cmd->proc)
    (cmd->proc)(source_p, caplist);
  return 0;
}

static struct Message cap_msgtab =
{
  .cmd = "CAP",
  .args_min = 2,
  .args_max = MAXPARA,
  .handlers[UNREGISTERED_HANDLER] = m_cap,
  .handlers[CLIENT_HANDLER] = m_cap,
  .handlers[SERVER_HANDLER] = m_ignore,
  .handlers[ENCAP_HANDLER] = m_ignore,
  .handlers[OPER_HANDLER] = m_cap
};

static void
module_init(void)
{
  /* First, let's sort the array */
  qsort(capab_list, CAPAB_LIST_LEN, sizeof(struct capabilities), (bqcmp)capab_sort);
  mod_add_cmd(&cap_msgtab);
}

static void
module_exit(void)
{
  mod_del_cmd(&cap_msgtab);
}

struct module module_entry =
{
  .version = "$Revision$",
  .modinit = module_init,
  .modexit = module_exit,
};
Revision:	8431
Committed:	Tue Mar 27 18:49:15 2018 UTC (7 years, 5 months ago) by michael
Content type:	text/x-csrc
File size:	13007 byte(s)
Log Message:	- Stylistic changes
#	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) 2006-2018 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
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 "ircd.h"
31	#include "numeric.h"
32	#include "user.h"
33	#include "send.h"
34	#include "parse.h"
35	#include "modules.h"
36	#include "irc_string.h"
37
38
39	enum
40	{
41	CAPFL_HIDDEN = 1 << 0, /*< Do not advertize this capability /
42	CAPFL_PROHIBIT = 1 << 1, /*< Client may not set this capability /
43	CAPFL_PROTO = 1 << 2, /*< Cap must be acknowledged by client /
44	CAPFL_STICKY = 1 << 3 /*< Cap may not be cleared once set /
45	};
46
47	typedef int (bqcmp)(const void , const void *);
48
49	static struct capabilities
50	{
51	unsigned int cap;
52	unsigned int flags;
53	const char *name;
54	size_t namelen;
55	} capab_list[] = {
56	#define _CAP(cap, flags, name) \
57	{ (cap), (flags), (name), sizeof(name) - 1 }
58	_CAP(CAP_UHNAMES, 0, "userhost-in-names"),
59	_CAP(CAP_MULTI_PREFIX, 0, "multi-prefix"),
60	_CAP(CAP_AWAY_NOTIFY, 0, "away-notify"),
61	_CAP(CAP_EXTENDED_JOIN, 0, "extended-join"),
62	_CAP(CAP_ACCOUNT_NOTIFY, 0, "account-notify"),
63	_CAP(CAP_INVITE_NOTIFY, 0, "invite-notify"),
64	_CAP(CAP_CHGHOST, 0, "chghost")
65	#undef _CAP
66	};
67
68	#define CAPAB_LIST_LEN (sizeof(capab_list) / sizeof(struct capabilities))
69
70	static int
71	capab_sort(const struct capabilities cap1, const struct capabilities cap2)
72	{
73	return strcasecmp(cap1->name, cap2->name);
74	}
75
76	static int
77	capab_search(const char key, const struct capabilities cap)
78	{
79	const char *rb = cap->name;
80
81	while (ToLower(key) == ToLower(rb)) /* Walk equivalent part of strings */
82	if (key++ == '\0') / Hit the end, all right... */
83	return 0;
84	else /* OK, let's move on... */
85	++rb;
86
87	/*
88	* If the character they differ on happens to be a space, and it happens
89	* to be the same length as the capability name, then we've found a
90	* match; otherwise, return the difference of the two.
91	*/
92	return (IsSpace(key) && rb == '\0') ? 0 : (ToLower(key) - ToLower(rb));
93	}
94
95	static struct capabilities *
96	find_cap(const char *caplist_p, int neg_p)
97	{
98	const char caplist = caplist_p;
99	struct capabilities *cap = NULL;
100
101	neg_p = 0; / Clear negative flag... */
102
103	/* Next, find first non-whitespace character... */
104	while (caplist && IsSpace(caplist))
105	++caplist;
106
107	/* We are now at the beginning of an element of the list; is it negative? */
108	if (*caplist == '-')
109	{
110	++caplist; /* Yes; step past the flag... */
111	neg_p = 1; / Remember that it is negative... */
112	}
113
114	/* OK, now see if we can look up the capability... */
115	if (*caplist)
116	{
117	if (!(cap = bsearch(caplist, capab_list, CAPAB_LIST_LEN,
118	sizeof(struct capabilities),
119	(bqcmp)capab_search)))
120	{
121	/* Couldn't find the capability; advance to first whitespace character */
122	while (caplist && !IsSpace(caplist))
123	++caplist;
124	}
125	else
126	caplist += cap->namelen; /* Advance to end of capability name */
127
128	/* Strip trailing spaces */
129	while (caplist && IsSpace(caplist))
130	++caplist;
131	}
132
133	assert(caplist != caplist_p \|\| !caplist); /* We must advance */
134
135	/* Move ahead in capability list string--or zero pointer if we hit end */
136	caplist_p = caplist ? caplist : NULL;
137
138	return cap; /* And return the capability (if any) */
139	}
140
141	/** Send a CAP \a subcmd list of capability changes to \a source_p.
142	* If more than one line is necessary, each line before the last has
143	* an added "*" parameter before that line's capability list.
144	* @param[in] source_p Client receiving capability list.
145	* @param[in] set Capabilities to show as set (with ack and sticky modifiers).
146	* @param[in] rem Capabalities to show as removed (with no other modifier).
147	* @param[in] subcmd Name of capability subcommand.
148	*/
149	static int
150	send_caplist(struct Client *source_p,
151	const unsigned int *const set,
152	const unsigned int const rem, const char subcmd)
153	{
154	char capbuf[IRCD_BUFSIZE] = "", pfx[16];
155	char cmdbuf[IRCD_BUFSIZE] = "";
156	unsigned int i, loc, len, pfx_len, clen;
157
158	/* Set up the buffer for the final LS message... */
159	clen = snprintf(cmdbuf, sizeof(capbuf), ":%s CAP %s %s ", me.name,
160	source_p->name[0] ? source_p->name : "*", subcmd);
161
162	for (i = 0, loc = 0; i < CAPAB_LIST_LEN; ++i)
163	{
164	const struct capabilities *cap = &capab_list[i];
165
166	/*
167	* This is a little bit subtle, but just involves applying de
168	* Morgan's laws to the obvious check: We must display the
169	* capability if (and only if) it is set in \a rem or \a set, or
170	* if both are null and the capability is hidden.
171	*/
172	if (!(rem && (*rem & cap->cap)) &&
173	!(set && (*set & cap->cap)) &&
174	(rem \|\| set \|\| (cap->flags & CAPFL_HIDDEN)))
175	continue;
176
177	/* Build the prefix (space separator and any modifiers needed). */
178	pfx_len = 0;
179
180	if (loc)
181	pfx[pfx_len++] = ' ';
182	if (rem && (*rem & cap->cap))
183	pfx[pfx_len++] = '-';
184	else
185	{
186	if (cap->flags & CAPFL_PROTO)
187	pfx[pfx_len++] = '~';
188	if (cap->flags & CAPFL_STICKY)
189	pfx[pfx_len++] = '=';
190	}
191
192	pfx[pfx_len] = '\0';
193
194	len = cap->namelen + pfx_len; /* How much we'd add... */
195
196	if (sizeof(capbuf) < (clen + loc + len + 15))
197	{
198	/* Would add too much; must flush */
199	sendto_one(source_p, "%s* :%s", cmdbuf, capbuf);
200	capbuf[(loc = 0)] = '\0'; /* Re-terminate the buffer... */
201	}
202
203	loc += snprintf(capbuf + loc, sizeof(capbuf) - loc,
204	"%s%s", pfx, cap->name);
205	}
206
207	sendto_one(source_p, "%s:%s", cmdbuf, capbuf);
208
209	return 0; /* Convenience return */
210	}
211
212	static int
213	cap_ls(struct Client source_p, const char caplist)
214	{
215	if (IsUnknown(source_p)) /* Registration hasn't completed; suspend it... */
216	source_p->connection->registration \|= REG_NEED_CAP;
217
218	return send_caplist(source_p, NULL, NULL, "LS"); /* Send list of capabilities */
219	}
220
221	static int
222	cap_req(struct Client source_p, const char caplist)
223	{
224	const char *cl = caplist;
225	struct capabilities *cap = NULL;
226	unsigned int set = 0, rem = 0;
227	unsigned int cs = source_p->connection->cap_client; /* capability set */
228	unsigned int as = source_p->connection->cap_active; /* active set */
229	int neg = 0;
230
231	if (IsUnknown(source_p)) /* Registration hasn't completed; suspend it... */
232	source_p->connection->registration \|= REG_NEED_CAP;
233
234	while (cl) { /* Walk through the capabilities list... */
235	if (!(cap = find_cap(&cl, &neg)) /* Look up capability... */
236	\|\| (!neg && (cap->flags & CAPFL_PROHIBIT)) /* Is it prohibited? */
237	\|\| (neg && (cap->flags & CAPFL_STICKY))) { /* Is it sticky? */
238	sendto_one(source_p, ":%s CAP %s NAK :%s", me.name,
239	source_p->name[0] ? source_p->name : "*", caplist);
240	return 0; /* Can't complete requested op... */
241	}
242
243	if (neg)
244	{
245	/* Set or clear the capability... */
246	rem \|= cap->cap;
247	set &= ~cap->cap;
248	cs &= ~cap->cap;
249
250	if (!(cap->flags & CAPFL_PROTO))
251	as &= ~cap->cap;
252	}
253	else
254	{
255	rem &= ~cap->cap;
256	set \|= cap->cap;
257	cs \|= cap->cap;
258
259	if (!(cap->flags & CAPFL_PROTO))
260	as \|= cap->cap;
261	}
262	}
263
264	/* Notify client of accepted changes and copy over results. */
265	send_caplist(source_p, &set, &rem, "ACK");
266
267	source_p->connection->cap_client = cs;
268	source_p->connection->cap_active = as;
269
270	return 0;
271	}
272
273	static int
274	cap_ack(struct Client source_p, const char caplist)
275	{
276	const char *cl = caplist;
277	struct capabilities *cap = NULL;
278	int neg = 0;
279
280	/*
281	* Coming from the client, this generally indicates that the client
282	* is using a new backwards-incompatible protocol feature. As such,
283	* it does not require further response from the server.
284	*/
285	while (cl)
286	{
287	/* Walk through the capabilities list... */
288	if (!(cap = find_cap(&cl, &neg)) \|\| /* Look up capability... */
289	(neg ? (source_p->connection->cap_client & cap->cap) :
290	!(source_p->connection->cap_client & cap->cap))) /* uh... */
291	continue;
292
293	/* Set or clear the active capability... */
294	if (neg)
295	{
296	if (cap->flags & CAPFL_STICKY)
297	continue; /* but don't clear sticky capabilities */
298
299	source_p->connection->cap_active &= ~cap->cap;
300	}
301	else
302	{
303	if (cap->flags & CAPFL_PROHIBIT)
304	continue; /* and don't set prohibited ones */
305
306	source_p->connection->cap_active \|= cap->cap;
307	}
308	}
309
310	return 0;
311	}
312
313	static int
314	cap_clear(struct Client source_p, const char caplist)
315	{
316	unsigned int cleared = 0;
317
318	for (unsigned int ii = 0; ii < CAPAB_LIST_LEN; ++ii)
319	{
320	const struct capabilities *cap = &capab_list[ii];
321
322	/* Only clear active non-sticky capabilities. */
323	if (!(source_p->connection->cap_client & cap->cap) \|\| (cap->flags & CAPFL_STICKY))
324	continue;
325
326	cleared \|= cap->cap;
327	source_p->connection->cap_client &= ~cap->cap;
328
329	if (!(cap->flags & CAPFL_PROTO))
330	source_p->connection->cap_active &= ~cap->cap;
331	}
332
333	return send_caplist(source_p, NULL, &cleared, "ACK");
334	}
335
336	static int
337	cap_end(struct Client source_p, const char caplist)
338	{
339	if (!IsUnknown(source_p)) /* Registration has completed... */
340	return 0; /* So just ignore the message... */
341
342	/* Capability negotiation is now done... */
343	source_p->connection->registration &= ~REG_NEED_CAP;
344
345	/* If client is now done... */
346	if (!source_p->connection->registration)
347	{
348	register_local_user(source_p);
349	return 0;
350	}
351
352	return 0; /* Can't do registration yet... */
353	}
354
355	static int
356	cap_list(struct Client source_p, const char caplist)
357	{
358	/* Send the list of the client's capabilities */
359	return send_caplist(source_p, &source_p->connection->cap_client, NULL, "LIST");
360	}
361
362	static struct subcmd
363	{
364	const char *cmd;
365	int (proc)(struct Client , const char *);
366	} cmdlist[] = {
367	{ "ACK", cap_ack },
368	{ "CLEAR", cap_clear },
369	{ "END", cap_end },
370	{ "LIST", cap_list },
371	{ "LS", cap_ls },
372	{ "NAK", NULL },
373	{ "REQ", cap_req }
374	};
375
376	static int
377	subcmd_search(const char cmd, const struct subcmd elem)
378	{
379	return strcasecmp(cmd, elem->cmd);
380	}
381
382	/*! \brief CAP command handler
383	*
384	* \param source_p Pointer to allocated Client struct from which the message
385	* originally comes from. This can be a local or remote client.
386	* \param parc Integer holding the number of supplied arguments.
387	* \param parv Argument vector where parv[0] .. parv[parc-1] are non-NULL
388	* pointers.
389	* \note Valid arguments for this command are:
390	* - parv[0] = command
391	* - parv[1] = CAP subcommand
392	* - parv[2] = space-separated list of capabilities
393	*/
394	static int
395	m_cap(struct Client source_p, int parc, char parv[])
396	{
397	const char subcmd = NULL, caplist = NULL;
398	struct subcmd *cmd = NULL;
399
400	if (EmptyString(parv[1])) /* A subcommand is required */
401	return 0;
402
403	subcmd = parv[1];
404
405	if (parc > 2) /* A capability list was provided */
406	caplist = parv[2];
407
408	/* Find the subcommand handler */
409	if (!(cmd = bsearch(subcmd, cmdlist,
410	sizeof(cmdlist) / sizeof(struct subcmd),
411	sizeof(struct subcmd), (bqcmp)subcmd_search)))
412	{
413	sendto_one_numeric(source_p, &me, ERR_INVALIDCAPCMD, subcmd);
414	return 0;
415	}
416
417	/* Then execute it... */
418	if (cmd->proc)
419	(cmd->proc)(source_p, caplist);
420	return 0;
421	}
422
423	static struct Message cap_msgtab =
424	{
425	.cmd = "CAP",
426	.args_min = 2,
427	.args_max = MAXPARA,
428	.handlers[UNREGISTERED_HANDLER] = m_cap,
429	.handlers[CLIENT_HANDLER] = m_cap,
430	.handlers[SERVER_HANDLER] = m_ignore,
431	.handlers[ENCAP_HANDLER] = m_ignore,
432	.handlers[OPER_HANDLER] = m_cap
433	};
434
435	static void
436	module_init(void)
437	{
438	/* First, let's sort the array */
439	qsort(capab_list, CAPAB_LIST_LEN, sizeof(struct capabilities), (bqcmp)capab_sort);
440	mod_add_cmd(&cap_msgtab);
441	}
442
443	static void
444	module_exit(void)
445	{
446	mod_del_cmd(&cap_msgtab);
447	}
448
449	struct module module_entry =
450	{
451	.version = "$Revision$",
452	.modinit = module_init,
453	.modexit = module_exit,
454	};