ircd-hybrid-8/modules/m_cap.c

/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *
 *  Copyright (C) 2004 Kevin L. Mitchell <klmitch@mit.edu>
 *  Copyright (C) 2006 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id$
 */

/** @file
 * @brief Capability negotiation commands
 * @version $Id$
 */

#include "stdinc.h"
#include "handlers.h"
#include "client.h"
#include "hash.h"
#include "ircd.h"
#include "numeric.h"
#include "s_conf.h"
#include "s_user.h"
#include "s_serv.h"
#include "send.h"
#include "msg.h"
#include "parse.h"
#include "modules.h"
#include "common.h"
#include "packet.h"
#include "irc_string.h"

static void m_cap(struct Client *, struct Client *, int, char *[]);

struct Message cap_msgtab = {
  "CAP", 0, 0, 2, 0, MFLG_SLOW, 0,
  { m_cap, m_cap, m_ignore, m_ignore, m_cap, m_ignore }
};

#ifndef STATIC_MODULES
void
_modinit(void)
{
  mod_add_cmd(&cap_msgtab);
}

void
_moddeinit(void)
{
  mod_del_cmd(&cap_msgtab);
}

const char *_version = "$Revision$";
#endif

#define CAPFL_HIDDEN    0x0001  /**< Do not advertize this capability */
#define CAPFL_PROHIBIT  0x0002  /**< Client may not set this capability */
#define CAPFL_PROTO     0x0004  /**< Cap must be acknowledged by client */
#define CAPFL_STICKY    0x0008  /**< 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_MULTI_PREFIX, 0, "multi-prefix")
#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)
{
  static int inited = 0;
  const char *caplist = *caplist_p;
  struct capabilities *cap = NULL;

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

  if (!inited)
  {
    /* First, let's sort the array... */
    qsort(capab_list, CAPAB_LIST_LEN, sizeof(struct capabilities), (bqcmp)capab_sort);
    ++inited;
  }

  /* 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 */
  }

  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 : 0;

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

/** Send a CAP \a subcmd list of capability changes to \a sptr.
 * If more than one line is necessary, each line before the last has
 * an added "*" parameter before that line's capability list.
 * @param[in] sptr 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 *sptr, unsigned int set,
             unsigned int rem, const char *subcmd)
{
  char capbuf[IRCD_BUFSIZE] = "", pfx[16];
  char cmdbuf[IRCD_BUFSIZE] = "";
  unsigned int i, loc, len, flags, pfx_len, clen;

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

  for (i = 0, loc = 0; i < CAPAB_LIST_LEN; ++i)
  {
    flags = capab_list[i].flags;

    /*
     * 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 & capab_list[i].cap)) &&
        !(set && (set & capab_list[i].cap)) &&
         (rem || set || (flags & CAPFL_HIDDEN)))
      continue;

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

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

    pfx[pfx_len] = '\0';

    len = capab_list[i].namelen + pfx_len;    /* how much we'd add... */

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

    loc += snprintf(capbuf + loc, sizeof(capbuf) - loc,
                    "%s%s", pfx, capab_list[i].name);
  }

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

  return 0;    /* convenience return */
}

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

  return send_caplist(sptr, 0, 0, "LS"); /* send list of capabilities */
}

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

  if (IsUnknown(sptr)) /* registration hasn't completed; suspend it... */
    sptr->localClient->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(sptr, ":%s CAP %s NAK :%s", me.name,
                 sptr->name[0] ? sptr->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(sptr, set, rem, "ACK");

  sptr->localClient->cap_client = cs;
  sptr->localClient->cap_active = as;

  return 0;
}

static int
cap_ack(struct Client *sptr, 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 ? (sptr->localClient->cap_active & cap->cap) :
              !(sptr->localClient->cap_active & cap->cap))) /* uh... */
      continue;

    if (neg)    /* set or clear the active capability... */
      sptr->localClient->cap_active &= ~cap->cap;
    else
      sptr->localClient->cap_active |=  cap->cap;
  }

  return 0;
}

static int
cap_clear(struct Client *sptr, const char *caplist)
{
  struct capabilities *cap = NULL;
  unsigned int ii;
  unsigned int cleared = 0;

  for (ii = 0; ii < CAPAB_LIST_LEN; ++ii)
  {
    cap = &capab_list[ii];

    /* Only clear active non-sticky capabilities. */
    if (!(sptr->localClient->cap_active & cap->cap) || (cap->flags & CAPFL_STICKY))
      continue;

    cleared |= cap->cap;
    sptr->localClient->cap_client &= ~cap->cap;

    if (!(cap->flags & CAPFL_PROTO))
      sptr->localClient->cap_active &= ~cap->cap;
  }

  return send_caplist(sptr, 0, cleared, "ACK");
}

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

  /* capability negotiation is now done... */
  sptr->localClient->registration &= ~REG_NEED_CAP;

  /* if client is now done... */
  if (!sptr->localClient->registration)
  {
    char buf[USERLEN + 1];

    strlcpy(buf, sptr->username, sizeof(buf));
    register_local_user(sptr, sptr, sptr->name, buf);
    return 0;
  }

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

static int
cap_list(struct Client *sptr, const char *caplist)
{
  /* Send the list of the client's capabilities */
  return send_caplist(sptr, sptr->localClient->cap_client, 0, "LIST");
}

static struct subcmd
{
  const char *cmd;
  int (*proc)(struct Client *sptr, const char *caplist);
} 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);
}

/** Handle a capability request or response from a client.
 * \param cptr Client that sent us the message.
 * \param sptr Original source of message.
 * \param parc Number of arguments.
 * \param parv Argument vector.
 */
static void
m_cap(struct Client *cptr, struct Client *sptr, int parc, char *parv[])
{
  char *subcmd = NULL, *caplist = NULL;
  struct subcmd *cmd = NULL;

  if (parc < 2 || EmptyString(parv[1]))    /* a subcommand is required */
    return;

  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(sptr, form_str(ERR_INVALIDCAPCMD),
               me.name, sptr->name, subcmd);
    return;
  }

  /* then execute it... */
  if (cmd->proc)
    (cmd->proc)(sptr, caplist);
}
Revision:	1028
Committed:	Sun Nov 8 13:03:38 2009 UTC (15 years, 9 months ago) by michael
Content type:	text/x-csrc
Original Path:	*ircd-hybrid/modules/m_cap.c*
File size:	12071 byte(s)
Log Message:	- move ircd-hybrid-7.2 to trunk
#	User	Rev	Content
1	michael	503	/*
2			* ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3			*
4			* Copyright (C) 2004 Kevin L. Mitchell <klmitch@mit.edu>
5			* Copyright (C) 2006 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			* $Id$
23			*/
24
25			/** @file
26			* @brief Capability negotiation commands
27			* @version $Id$
28			*/
29
30			#include "stdinc.h"
31			#include "handlers.h"
32			#include "client.h"
33			#include "hash.h"
34			#include "ircd.h"
35			#include "numeric.h"
36			#include "s_conf.h"
37			#include "s_user.h"
38			#include "s_serv.h"
39			#include "send.h"
40			#include "msg.h"
41			#include "parse.h"
42			#include "modules.h"
43			#include "common.h"
44			#include "packet.h"
45			#include "irc_string.h"
46
47			static void m_cap(struct Client , struct Client , int, char *[]);
48
49			struct Message cap_msgtab = {
50			"CAP", 0, 0, 2, 0, MFLG_SLOW, 0,
51			{ m_cap, m_cap, m_ignore, m_ignore, m_cap, m_ignore }
52			};
53
54			#ifndef STATIC_MODULES
55			void
56			_modinit(void)
57			{
58			mod_add_cmd(&cap_msgtab);
59			}
60
61			void
62			_moddeinit(void)
63			{
64			mod_del_cmd(&cap_msgtab);
65			}
66
67	michael	953	const char *_version = "$Revision$";
68	michael	503	#endif
69
70			#define CAPFL_HIDDEN 0x0001 /*< Do not advertize this capability /
71			#define CAPFL_PROHIBIT 0x0002 /*< Client may not set this capability /
72			#define CAPFL_PROTO 0x0004 /*< Cap must be acknowledged by client /
73			#define CAPFL_STICKY 0x0008 /*< Cap may not be cleared once set /
74
75			typedef int (bqcmp)(const void , const void *);
76
77			static struct capabilities
78			{
79			unsigned int cap;
80			unsigned int flags;
81			const char *name;
82			size_t namelen;
83			} capab_list[] = {
84			#define _CAP(cap, flags, name) \
85			{ (cap), (flags), (name), sizeof(name) - 1 }
86			_CAP(CAP_MULTI_PREFIX, 0, "multi-prefix")
87			#undef _CAP
88			};
89
90			#define CAPAB_LIST_LEN (sizeof(capab_list) / sizeof(struct capabilities))
91
92			static int
93			capab_sort(const struct capabilities cap1, const struct capabilities cap2)
94			{
95	michael	536	return strcasecmp(cap1->name, cap2->name);
96	michael	503	}
97
98			static int
99			capab_search(const char key, const struct capabilities cap)
100			{
101			const char *rb = cap->name;
102
103			while (ToLower(key) == ToLower(rb)) /* walk equivalent part of strings */
104			if (key++ == '\0') / hit the end, all right... */
105			return 0;
106			else /* OK, let's move on... */
107			rb++;
108
109	michael	872	/*
110			* If the character they differ on happens to be a space, and it happens
111	michael	503	* to be the same length as the capability name, then we've found a
112			* match; otherwise, return the difference of the two.
113			*/
114			return (IsSpace(key) && rb == '\0') ? 0 : (ToLower(key) - ToLower(rb));
115			}
116
117			static struct capabilities *
118			find_cap(const char *caplist_p, int neg_p)
119			{
120			static int inited = 0;
121			const char caplist = caplist_p;
122	michael	872	struct capabilities *cap = NULL;
123	michael	503
124			neg_p = 0; / clear negative flag... */
125
126			if (!inited)
127			{
128			/* First, let's sort the array... */
129			qsort(capab_list, CAPAB_LIST_LEN, sizeof(struct capabilities), (bqcmp)capab_sort);
130			++inited;
131			}
132
133			/* Next, find first non-whitespace character... */
134			while (caplist && IsSpace(caplist))
135			++caplist;
136
137			/* We are now at the beginning of an element of the list; is it negative? */
138	michael	872	if (*caplist == '-')
139			{
140	michael	503	++caplist; /* yes; step past the flag... */
141			neg_p = 1; / remember that it is negative... */
142			}
143
144			/* OK, now see if we can look up the capability... */
145	michael	872	if (*caplist)
146			{
147	michael	503	if (!(cap = bsearch(caplist, capab_list, CAPAB_LIST_LEN,
148			sizeof(struct capabilities),
149			(bqcmp)capab_search)))
150			{
151			/* Couldn't find the capability; advance to first whitespace character */
152			while (caplist && !IsSpace(caplist))
153			++caplist;
154			}
155			else
156			caplist += cap->namelen; /* advance to end of capability name */
157			}
158
159			assert(caplist != caplist_p \|\| !caplist); /* we must advance */
160
161			/* move ahead in capability list string--or zero pointer if we hit end */
162			caplist_p = caplist ? caplist : 0;
163
164			return cap; /* and return the capability (if any) */
165			}
166
167			/** Send a CAP \a subcmd list of capability changes to \a sptr.
168			* If more than one line is necessary, each line before the last has
169			* an added "*" parameter before that line's capability list.
170			* @param[in] sptr Client receiving capability list.
171			* @param[in] set Capabilities to show as set (with ack and sticky modifiers).
172			* @param[in] rem Capabalities to show as removed (with no other modifier).
173			* @param[in] subcmd Name of capability subcommand.
174			*/
175			static int
176			send_caplist(struct Client *sptr, unsigned int set,
177			unsigned int rem, const char *subcmd)
178			{
179			char capbuf[IRCD_BUFSIZE] = "", pfx[16];
180			char cmdbuf[IRCD_BUFSIZE] = "";
181	michael	575	unsigned int i, loc, len, flags, pfx_len, clen;
182	michael	503
183			/* set up the buffer for the final LS message... */
184			clen = snprintf(cmdbuf, sizeof(capbuf), ":%s CAP %s %s ", me.name,
185			sptr->name[0] ? sptr->name : "*", subcmd);
186
187			for (i = 0, loc = 0; i < CAPAB_LIST_LEN; ++i)
188			{
189			flags = capab_list[i].flags;
190
191			/*
192			* This is a little bit subtle, but just involves applying de
193			* Morgan's laws to the obvious check: We must display the
194			* capability if (and only if) it is set in \a rem or \a set, or
195			* if both are null and the capability is hidden.
196			*/
197			if (!(rem && (rem & capab_list[i].cap)) &&
198			!(set && (set & capab_list[i].cap)) &&
199			(rem \|\| set \|\| (flags & CAPFL_HIDDEN)))
200			continue;
201
202			/* Build the prefix (space separator and any modifiers needed). */
203			pfx_len = 0;
204
205			if (loc)
206			pfx[pfx_len++] = ' ';
207			if (rem && (rem & capab_list[i].cap))
208			pfx[pfx_len++] = '-';
209			else
210			{
211			if (flags & CAPFL_PROTO)
212			pfx[pfx_len++] = '~';
213			if (flags & CAPFL_STICKY)
214			pfx[pfx_len++] = '=';
215			}
216
217			pfx[pfx_len] = '\0';
218
219			len = capab_list[i].namelen + pfx_len; /* how much we'd add... */
220
221			if (sizeof(capbuf) < (clen + loc + len + 15))
222			{
223			/* would add too much; must flush */
224			sendto_one(sptr, "%s* :%s", cmdbuf, capbuf);
225			capbuf[(loc = 0)] = '\0'; /* re-terminate the buffer... */
226			}
227
228			loc += snprintf(capbuf + loc, sizeof(capbuf) - loc,
229			"%s%s", pfx, capab_list[i].name);
230			}
231
232			sendto_one(sptr, "%s:%s", cmdbuf, capbuf);
233
234			return 0; /* convenience return */
235			}
236
237			static int
238			cap_ls(struct Client sptr, const char caplist)
239			{
240			if (IsUnknown(sptr)) /* registration hasn't completed; suspend it... */
241			sptr->localClient->registration \|= REG_NEED_CAP;
242
243			return send_caplist(sptr, 0, 0, "LS"); /* send list of capabilities */
244			}
245
246			static int
247			cap_req(struct Client sptr, const char caplist)
248			{
249			const char *cl = caplist;
250	michael	872	struct capabilities *cap = NULL;
251	michael	503	unsigned int set = 0, rem = 0;
252			unsigned int cs = sptr->localClient->cap_client; /* capability set */
253			unsigned int as = sptr->localClient->cap_active; /* active set */
254	michael	872	int neg = 0;
255	michael	503
256			if (IsUnknown(sptr)) /* registration hasn't completed; suspend it... */
257			sptr->localClient->registration \|= REG_NEED_CAP;
258
259			while (cl) { /* walk through the capabilities list... */
260			if (!(cap = find_cap(&cl, &neg)) /* look up capability... */
261			\|\| (!neg && (cap->flags & CAPFL_PROHIBIT)) /* is it prohibited? */
262			\|\| (neg && (cap->flags & CAPFL_STICKY))) { /* is it sticky? */
263			sendto_one(sptr, ":%s CAP %s NAK :%s", me.name,
264			sptr->name[0] ? sptr->name : "*", caplist);
265			return 0; /* can't complete requested op... */
266			}
267
268			if (neg)
269			{
270			/* set or clear the capability... */
271			rem \|= cap->cap;
272			set &= ~cap->cap;
273			cs &= ~cap->cap;
274
275			if (!(cap->flags & CAPFL_PROTO))
276			as &= ~cap->cap;
277			}
278			else
279			{
280			rem &= ~cap->cap;
281			set \|= cap->cap;
282			cs \|= cap->cap;
283
284			if (!(cap->flags & CAPFL_PROTO))
285			as \|= cap->cap;
286			}
287			}
288
289			/* Notify client of accepted changes and copy over results. */
290			send_caplist(sptr, set, rem, "ACK");
291
292			sptr->localClient->cap_client = cs;
293			sptr->localClient->cap_active = as;
294
295			return 0;
296			}
297
298			static int
299			cap_ack(struct Client sptr, const char caplist)
300			{
301			const char *cl = caplist;
302			struct capabilities *cap = NULL;
303	michael	872	int neg = 0;
304	michael	503
305			/*
306			* Coming from the client, this generally indicates that the client
307			* is using a new backwards-incompatible protocol feature. As such,
308			* it does not require further response from the server.
309			*/
310			while (cl)
311			{
312			/* walk through the capabilities list... */
313			if (!(cap = find_cap(&cl, &neg)) \|\| /* look up capability... */
314			(neg ? (sptr->localClient->cap_active & cap->cap) :
315			!(sptr->localClient->cap_active & cap->cap))) /* uh... */
316			continue;
317
318			if (neg) /* set or clear the active capability... */
319			sptr->localClient->cap_active &= ~cap->cap;
320			else
321			sptr->localClient->cap_active \|= cap->cap;
322			}
323
324			return 0;
325			}
326
327			static int
328			cap_clear(struct Client sptr, const char caplist)
329			{
330	michael	872	struct capabilities *cap = NULL;
331	michael	503	unsigned int ii;
332			unsigned int cleared = 0;
333
334			for (ii = 0; ii < CAPAB_LIST_LEN; ++ii)
335			{
336			cap = &capab_list[ii];
337
338			/* Only clear active non-sticky capabilities. */
339			if (!(sptr->localClient->cap_active & cap->cap) \|\| (cap->flags & CAPFL_STICKY))
340			continue;
341
342			cleared \|= cap->cap;
343			sptr->localClient->cap_client &= ~cap->cap;
344
345			if (!(cap->flags & CAPFL_PROTO))
346			sptr->localClient->cap_active &= ~cap->cap;
347			}
348
349			return send_caplist(sptr, 0, cleared, "ACK");
350			}
351
352			static int
353			cap_end(struct Client sptr, const char caplist)
354			{
355			if (!IsUnknown(sptr)) /* registration has completed... */
356			return 0; /* so just ignore the message... */
357
358			/* capability negotiation is now done... */
359			sptr->localClient->registration &= ~REG_NEED_CAP;
360
361			/* if client is now done... */
362			if (!sptr->localClient->registration)
363			{
364			char buf[USERLEN + 1];
365
366			strlcpy(buf, sptr->username, sizeof(buf));
367			register_local_user(sptr, sptr, sptr->name, buf);
368			return 0;
369			}
370
371			return 0; /* Can't do registration yet... */
372			}
373
374			static int
375			cap_list(struct Client sptr, const char caplist)
376			{
377			/* Send the list of the client's capabilities */
378			return send_caplist(sptr, sptr->localClient->cap_client, 0, "LIST");
379			}
380
381			static struct subcmd
382			{
383	michael	575	const char *cmd;
384	michael	503	int (proc)(struct Client sptr, const char *caplist);
385			} cmdlist[] = {
386			{ "ACK", cap_ack },
387			{ "CLEAR", cap_clear },
388			{ "END", cap_end },
389			{ "LIST", cap_list },
390			{ "LS", cap_ls },
391	michael	575	{ "NAK", NULL },
392	michael	503	{ "REQ", cap_req }
393			};
394
395			static int
396			subcmd_search(const char cmd, const struct subcmd elem)
397			{
398	michael	536	return strcasecmp(cmd, elem->cmd);
399	michael	503	}
400
401			/** Handle a capability request or response from a client.
402			* \param cptr Client that sent us the message.
403			* \param sptr Original source of message.
404			* \param parc Number of arguments.
405			* \param parv Argument vector.
406			*/
407			static void
408			m_cap(struct Client cptr, struct Client sptr, int parc, char *parv[])
409			{
410	michael	872	char subcmd = NULL, caplist = NULL;
411	michael	503	struct subcmd *cmd = NULL;
412
413	michael	872	if (parc < 2 \|\| EmptyString(parv[1])) /* a subcommand is required */
414	michael	503	return;
415
416			subcmd = parv[1];
417
418			if (parc > 2) /* a capability list was provided */
419			caplist = parv[2];
420
421			/* find the subcommand handler */
422			if (!(cmd = bsearch(subcmd, cmdlist,
423			sizeof(cmdlist) / sizeof(struct subcmd),
424			sizeof(struct subcmd), (bqcmp)subcmd_search)))
425			{
426			sendto_one(sptr, form_str(ERR_INVALIDCAPCMD),
427			me.name, sptr->name, subcmd);
428			return;
429			}
430
431			/* then execute it... */
432			if (cmd->proc)
433			(cmd->proc)(sptr, caplist);
434			}