modules/m_cap.c

   1 /* modules/m_cap.c
   2  *
   3  *  Copyright (C) 2005 Lee Hardy <lee@leeh.co.uk>
   4  *  Copyright (C) 2005 ircd-ratbox development team
   5  *  Copyright (C) 2016 William Pitcock <nenolod@dereferenced.org>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are
   9  * met:
  10  *
  11  * 1.Redistributions of source code must retain the above copyright notice,
  12  *   this list of conditions and the following disclaimer.
  13  * 2.Redistributions in binary form must reproduce the above copyright
  14  *   notice, this list of conditions and the following disclaimer in the
  15  *   documentation and/or other materials provided with the distribution.
  16  * 3.The name of the author may not be used to endorse or promote products
  17  *   derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  28  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "stdinc.h"
  33 #include "class.h"
  34 #include "client.h"
  35 #include "match.h"
  36 #include "ircd.h"
  37 #include "numeric.h"
  38 #include "msg.h"
  39 #include "parse.h"
  40 #include "modules.h"
  41 #include "s_serv.h"
  42 #include "s_user.h"
  43 #include "send.h"
  44 #include "s_conf.h"
  45 #include "hash.h"
  46
  47 static const char cap_desc[] = "Provides the commands used for client capability negotiation";
  48
  49 typedef int (*bqcmp)(const void *, const void *);
  50
  51 static void m_cap(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  52
  53 struct Message cap_msgtab = {
  54         "CAP", 0, 0, 0, 0,
  55         {{m_cap, 2}, {m_cap, 2}, mg_ignore, mg_ignore, mg_ignore, {m_cap, 2}}
  56 };
  57
  58 mapi_clist_av1 cap_clist[] = { &cap_msgtab, NULL };
  59
  60 DECLARE_MODULE_AV2(cap, NULL, NULL, cap_clist, NULL, NULL, NULL, NULL, cap_desc);
  61
  62 #define IsCapableEntry(c, e)            IsCapable(c, 1 << (e)->value)
  63 #define HasCapabilityFlag(c, f)         (c->ownerdata != NULL && (((struct ClientCapability *)c->ownerdata)->flags & (f)) == f)
  64
  65 static inline int
  66 clicap_visible(struct Client *client_p, const struct CapabilityEntry *cap)
  67 {
  68         struct ClientCapability *clicap;
  69
  70         /* orphaned caps shouldn't be visible */
  71         if (cap->flags & CAP_ORPHANED)
  72                 return 0;
  73
  74         if (cap->ownerdata == NULL)
  75                 return 1;
  76
  77         clicap = cap->ownerdata;
  78         if (clicap->visible == NULL)
  79                 return 1;
  80
  81         return clicap->visible(client_p);
  82 }
  83
  84 /* clicap_find()
  85  *   Used iteratively over a buffer, extracts individual cap tokens.
  86  *
  87  * Inputs: buffer to start iterating over (NULL to iterate over existing buf)
  88  *         int pointer to whether the cap token is negated
  89  *         int pointer to whether we finish with success
  90  * Ouputs: Cap entry if found, NULL otherwise.
  91  */
  92 static struct CapabilityEntry *
  93 clicap_find(const char *data, int *negate, int *finished)
  94 {
  95         static char buf[BUFSIZE];
  96         static char *p;
  97         struct CapabilityEntry *cap;
  98         char *s;
  99
 100         *negate = 0;
 101
 102         if(data)
 103         {
 104                 rb_strlcpy(buf, data, sizeof(buf));
 105                 p = buf;
 106         }
 107
 108         if(*finished)
 109                 return NULL;
 110
 111         /* skip any whitespace */
 112         while(*p && IsSpace(*p))
 113                 p++;
 114
 115         if(EmptyString(p))
 116         {
 117                 *finished = 1;
 118                 return NULL;
 119         }
 120
 121         if(*p == '-')
 122         {
 123                 *negate = 1;
 124                 p++;
 125
 126                 /* someone sent a '-' without a parameter.. */
 127                 if(*p == '\0')
 128                         return NULL;
 129         }
 130
 131         if((s = strchr(p, ' ')))
 132                 *s++ = '\0';
 133
 134         if((cap = capability_find(cli_capindex, p)) != NULL)
 135         {
 136                 if(s)
 137                         p = s;
 138                 else
 139                         *finished = 1;
 140         }
 141
 142         return cap;
 143 }
 144
 145 /* clicap_generate()
 146  *   Generates a list of capabilities.
 147  *
 148  * Inputs: client to send to, subcmd to send,
 149  *         flags to match against: 0 to do none, -1 if client has no flags,
 150  *         int to whether we are doing CAP CLEAR
 151  * Outputs: None
 152  */
 153 static void
 154 clicap_generate(struct Client *source_p, const char *subcmd, int flags, int clear)
 155 {
 156         char buf[BUFSIZE] = { 0 };
 157         char capbuf[BUFSIZE] = { 0 };
 158         int buflen = 0;
 159         int curlen, mlen;
 160         struct CapabilityEntry *entry;
 161         struct DictionaryIter iter;
 162
 163         mlen = snprintf(buf, sizeof buf, ":%s CAP %s %s",
 164                         me.name,
 165                         EmptyString(source_p->name) ? "*" : source_p->name,
 166                         subcmd);
 167
 168         /* shortcut, nothing to do */
 169         if(flags == -1)
 170         {
 171                 sendto_one(source_p, "%s :", buf);
 172                 return;
 173         }
 174
 175         DICTIONARY_FOREACH(entry, &iter, cli_capindex->cap_dict)
 176         {
 177                 size_t caplen = 0;
 178                 struct ClientCapability *clicap = entry->ownerdata;
 179                 const char *data = NULL;
 180
 181                 if(flags)
 182                 {
 183                         if(!IsCapableEntry(source_p, entry))
 184                                 continue;
 185                         /* they are capable of this, check sticky */
 186                         else if(clear && HasCapabilityFlag(entry, CLICAP_FLAGS_STICKY))
 187                                 continue;
 188                 }
 189
 190                 if (!clicap_visible(source_p, entry))
 191                         continue;
 192
 193                 caplen = strlen(entry->cap);
 194                 if (!flags && (source_p->flags & FLAGS_CLICAP_DATA) && clicap != NULL && clicap->data != NULL)
 195                         data = clicap->data(source_p);
 196
 197                 if (data != NULL)
 198                         caplen += strlen(data) + 1;
 199
 200                 /* \r\n\0, possible "-~=", space, " *" */
 201                 if(buflen + mlen >= BUFSIZE - 10)
 202                 {
 203                         /* remove our trailing space -- if buflen == mlen
 204                          * here, we didnt even succeed in adding one.
 205                          */
 206                         capbuf[buflen] = '\0';
 207
 208                         sendto_one(source_p, "%s * :%s", buf, capbuf);
 209
 210                         buflen = mlen;
 211                         memset(capbuf, 0, sizeof capbuf);
 212                 }
 213
 214                 buflen = rb_snprintf_append(capbuf, sizeof capbuf, "%s%s%s%s ",
 215                                 clear ? "-" : "", entry->cap, data != NULL ? "=" : "", data != NULL ? data : "");
 216         }
 217
 218         /* remove trailing space */
 219         capbuf[buflen] = '\0';
 220
 221         sendto_one(source_p, "%s :%s", buf, capbuf);
 222 }
 223
 224 static void
 225 cap_ack(struct Client *source_p, const char *arg)
 226 {
 227         struct CapabilityEntry *cap;
 228         int capadd = 0, capdel = 0;
 229         int finished = 0, negate;
 230
 231         if(EmptyString(arg))
 232                 return;
 233
 234         for(cap = clicap_find(arg, &negate, &finished); cap;
 235             cap = clicap_find(NULL, &negate, &finished))
 236         {
 237                 /* sent an ACK for something they havent REQd */
 238                 if(!IsCapableEntry(source_p, cap))
 239                         continue;
 240
 241                 if(negate)
 242                 {
 243                         /* dont let them ack something sticky off */
 244                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 245                                 continue;
 246
 247                         capdel |= (1 << cap->value);
 248                 }
 249                 else
 250                         capadd |= (1 << cap->value);
 251         }
 252
 253         source_p->localClient->caps |= capadd;
 254         source_p->localClient->caps &= ~capdel;
 255 }
 256
 257 static void
 258 cap_clear(struct Client *source_p, const char *arg)
 259 {
 260         clicap_generate(source_p, "ACK",
 261                         source_p->localClient->caps ? source_p->localClient->caps : -1, 1);
 262
 263         source_p->localClient->caps = 0;
 264 }
 265
 266 static void
 267 cap_end(struct Client *source_p, const char *arg)
 268 {
 269         if(IsRegistered(source_p))
 270                 return;
 271
 272         source_p->flags &= ~FLAGS_CLICAP;
 273
 274         if(source_p->name[0] && source_p->flags & FLAGS_SENTUSER)
 275         {
 276                 register_local_user(source_p, source_p);
 277         }
 278 }
 279
 280 static void
 281 cap_list(struct Client *source_p, const char *arg)
 282 {
 283         /* list of what theyre currently using */
 284         clicap_generate(source_p, "LIST",
 285                         source_p->localClient->caps ? source_p->localClient->caps : -1, 0);
 286 }
 287
 288 static void
 289 cap_ls(struct Client *source_p, const char *arg)
 290 {
 291         if(!IsRegistered(source_p))
 292                 source_p->flags |= FLAGS_CLICAP;
 293
 294         if (arg != NULL && !strcmp(arg, "302"))
 295         {
 296                 source_p->flags |= FLAGS_CLICAP_DATA;
 297                 source_p->localClient->caps |= CLICAP_CAP_NOTIFY;
 298         }
 299
 300         /* list of what we support */
 301         clicap_generate(source_p, "LS", 0, 0);
 302 }
 303
 304 static void
 305 cap_req(struct Client *source_p, const char *arg)
 306 {
 307         char buf[BUFSIZE];
 308         char pbuf[2][BUFSIZE];
 309         struct CapabilityEntry *cap;
 310         int buflen, plen;
 311         int i = 0;
 312         int capadd = 0, capdel = 0;
 313         int finished = 0, negate;
 314
 315         if(!IsRegistered(source_p))
 316                 source_p->flags |= FLAGS_CLICAP;
 317
 318         if(EmptyString(arg))
 319                 return;
 320
 321         buflen = snprintf(buf, sizeof(buf), ":%s CAP %s ACK",
 322                         me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 323
 324         pbuf[0][0] = '\0';
 325         plen = 0;
 326
 327         for(cap = clicap_find(arg, &negate, &finished); cap;
 328             cap = clicap_find(NULL, &negate, &finished))
 329         {
 330                 size_t namelen = strlen(cap->cap);
 331
 332                 /* filled the first array, but cant send it in case the
 333                  * request fails.  one REQ should never fill more than two
 334                  * buffers --fl
 335                  */
 336                 if(buflen + plen + namelen + 6 >= BUFSIZE)
 337                 {
 338                         pbuf[1][0] = '\0';
 339                         plen = 0;
 340                         i = 1;
 341                 }
 342
 343                 if(negate)
 344                 {
 345                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 346                         {
 347                                 finished = 0;
 348                                 break;
 349                         }
 350
 351                         strcat(pbuf[i], "-");
 352                         plen++;
 353
 354                         capdel |= (1 << cap->value);
 355                 }
 356                 else
 357                 {
 358                         if (!clicap_visible(source_p, cap))
 359                         {
 360                                 finished = 0;
 361                                 break;
 362                         }
 363
 364                         capadd |= (1 << cap->value);
 365                 }
 366
 367                 /* XXX this probably should exclude REQACK'd caps from capadd/capdel, but keep old behaviour for now */
 368                 if(HasCapabilityFlag(cap, CLICAP_FLAGS_REQACK))
 369                 {
 370                         strcat(pbuf[i], "~");
 371                         plen++;
 372                 }
 373
 374                 strcat(pbuf[i], cap->cap);
 375                 if (!finished) {
 376                         strcat(pbuf[i], " ");
 377                         plen += (namelen + 1);
 378                 }
 379         }
 380
 381         if(!finished)
 382         {
 383                 sendto_one(source_p, ":%s CAP %s NAK :%s",
 384                         me.name, EmptyString(source_p->name) ? "*" : source_p->name, arg);
 385                 return;
 386         }
 387
 388         if(i)
 389         {
 390                 sendto_one(source_p, "%s * :%s", buf, pbuf[0]);
 391                 sendto_one(source_p, "%s :%s", buf, pbuf[1]);
 392         }
 393         else
 394                 sendto_one(source_p, "%s :%s", buf, pbuf[0]);
 395
 396         source_p->localClient->caps |= capadd;
 397         source_p->localClient->caps &= ~capdel;
 398 }
 399
 400 static struct clicap_cmd
 401 {
 402         const char *cmd;
 403         void (*func)(struct Client *source_p, const char *arg);
 404 } clicap_cmdlist[] = {
 405         /* This list *MUST* be in alphabetical order */
 406         { "ACK",        cap_ack         },
 407         { "CLEAR",      cap_clear       },
 408         { "END",        cap_end         },
 409         { "LIST",       cap_list        },
 410         { "LS",         cap_ls          },
 411         { "REQ",        cap_req         },
 412 };
 413
 414 static int
 415 clicap_cmd_search(const char *command, struct clicap_cmd *entry)
 416 {
 417         return irccmp(command, entry->cmd);
 418 }
 419
 420 static void
 421 m_cap(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
 422 {
 423         struct clicap_cmd *cmd;
 424
 425         if(!(cmd = bsearch(parv[1], clicap_cmdlist,
 426                                 sizeof(clicap_cmdlist) / sizeof(struct clicap_cmd),
 427                                 sizeof(struct clicap_cmd), (bqcmp) clicap_cmd_search)))
 428         {
 429                 sendto_one(source_p, form_str(ERR_INVALIDCAPCMD),
 430                                 me.name, EmptyString(source_p->name) ? "*" : source_p->name,
 431                                 parv[1]);
 432                 return;
 433         }
 434
 435         (cmd->func)(source_p, parv[2]);
 436 }