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  * Outputs: None
 151  */
 152 static void
 153 clicap_generate(struct Client *source_p, const char *subcmd, int flags)
 154 {
 155         char buf[BUFSIZE] = { 0 };
 156         char capbuf[BUFSIZE] = { 0 };
 157         int buflen = 0;
 158         int mlen;
 159         struct CapabilityEntry *entry;
 160         struct DictionaryIter iter;
 161
 162         mlen = snprintf(buf, sizeof buf, ":%s CAP %s %s",
 163                         me.name,
 164                         EmptyString(source_p->name) ? "*" : source_p->name,
 165                         subcmd);
 166
 167         /* shortcut, nothing to do */
 168         if(flags == -1)
 169         {
 170                 sendto_one(source_p, "%s :", buf);
 171                 return;
 172         }
 173
 174         DICTIONARY_FOREACH(entry, &iter, cli_capindex->cap_dict)
 175         {
 176                 size_t caplen = 0;
 177                 struct ClientCapability *clicap = entry->ownerdata;
 178                 const char *data = NULL;
 179
 180                 if(flags && !IsCapableEntry(source_p, entry))
 181                         continue;
 182
 183                 if (!clicap_visible(source_p, entry))
 184                         continue;
 185
 186                 caplen = strlen(entry->cap);
 187                 if (!flags && (source_p->flags & FLAGS_CLICAP_DATA) && clicap != NULL && clicap->data != NULL)
 188                         data = clicap->data(source_p);
 189
 190                 if (data != NULL)
 191                         caplen += strlen(data) + 1;
 192
 193                 /* \r\n\0, possible "-~=", space, " *" */
 194                 if(buflen + mlen >= BUFSIZE - 10)
 195                 {
 196                         /* remove our trailing space -- if buflen == mlen
 197                          * here, we didnt even succeed in adding one.
 198                          */
 199                         capbuf[buflen] = '\0';
 200
 201                         sendto_one(source_p, "%s * :%s", buf, capbuf);
 202
 203                         buflen = mlen;
 204                         memset(capbuf, 0, sizeof capbuf);
 205                 }
 206
 207                 buflen = rb_snprintf_append(capbuf, sizeof capbuf, "%s%s%s ",
 208                                 entry->cap, data != NULL ? "=" : "", data != NULL ? data : "");
 209         }
 210
 211         /* remove trailing space */
 212         capbuf[buflen] = '\0';
 213
 214         sendto_one(source_p, "%s :%s", buf, capbuf);
 215 }
 216
 217 static void
 218 cap_ack(struct Client *source_p, const char *arg)
 219 {
 220         struct CapabilityEntry *cap;
 221         int capadd = 0, capdel = 0;
 222         int finished = 0, negate;
 223
 224         if(EmptyString(arg))
 225                 return;
 226
 227         for(cap = clicap_find(arg, &negate, &finished); cap;
 228             cap = clicap_find(NULL, &negate, &finished))
 229         {
 230                 /* sent an ACK for something they havent REQd */
 231                 if(!IsCapableEntry(source_p, cap))
 232                         continue;
 233
 234                 if(negate)
 235                 {
 236                         /* dont let them ack something sticky off */
 237                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 238                                 continue;
 239
 240                         capdel |= (1 << cap->value);
 241                 }
 242                 else
 243                         capadd |= (1 << cap->value);
 244         }
 245
 246         source_p->localClient->caps |= capadd;
 247         source_p->localClient->caps &= ~capdel;
 248 }
 249
 250 static void
 251 cap_end(struct Client *source_p, const char *arg)
 252 {
 253         if(IsRegistered(source_p))
 254                 return;
 255
 256         source_p->flags &= ~FLAGS_CLICAP;
 257
 258         if(source_p->name[0] && source_p->flags & FLAGS_SENTUSER)
 259         {
 260                 register_local_user(source_p, source_p);
 261         }
 262 }
 263
 264 static void
 265 cap_list(struct Client *source_p, const char *arg)
 266 {
 267         /* list of what theyre currently using */
 268         clicap_generate(source_p, "LIST",
 269                         source_p->localClient->caps ? source_p->localClient->caps : -1);
 270 }
 271
 272 static void
 273 cap_ls(struct Client *source_p, const char *arg)
 274 {
 275         if(!IsRegistered(source_p))
 276                 source_p->flags |= FLAGS_CLICAP;
 277
 278         if (arg != NULL && !strcmp(arg, "302"))
 279         {
 280                 source_p->flags |= FLAGS_CLICAP_DATA;
 281                 source_p->localClient->caps |= CLICAP_CAP_NOTIFY;
 282         }
 283
 284         /* list of what we support */
 285         clicap_generate(source_p, "LS", 0);
 286 }
 287
 288 static void
 289 cap_req(struct Client *source_p, const char *arg)
 290 {
 291         char buf[BUFSIZE];
 292         char pbuf[2][BUFSIZE];
 293         struct CapabilityEntry *cap;
 294         int buflen, plen;
 295         int i = 0;
 296         int capadd = 0, capdel = 0;
 297         int finished = 0, negate;
 298
 299         if(!IsRegistered(source_p))
 300                 source_p->flags |= FLAGS_CLICAP;
 301
 302         if(EmptyString(arg))
 303                 return;
 304
 305         buflen = snprintf(buf, sizeof(buf), ":%s CAP %s ACK",
 306                         me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 307
 308         pbuf[0][0] = '\0';
 309         plen = 0;
 310
 311         for(cap = clicap_find(arg, &negate, &finished); cap;
 312             cap = clicap_find(NULL, &negate, &finished))
 313         {
 314                 size_t namelen = strlen(cap->cap);
 315
 316                 /* filled the first array, but cant send it in case the
 317                  * request fails.  one REQ should never fill more than two
 318                  * buffers --fl
 319                  */
 320                 if(buflen + plen + namelen + 6 >= BUFSIZE)
 321                 {
 322                         pbuf[1][0] = '\0';
 323                         plen = 0;
 324                         i = 1;
 325                 }
 326
 327                 if(negate)
 328                 {
 329                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 330                         {
 331                                 finished = 0;
 332                                 break;
 333                         }
 334
 335                         strcat(pbuf[i], "-");
 336                         plen++;
 337
 338                         capdel |= (1 << cap->value);
 339                 }
 340                 else
 341                 {
 342                         if (!clicap_visible(source_p, cap))
 343                         {
 344                                 finished = 0;
 345                                 break;
 346                         }
 347
 348                         capadd |= (1 << cap->value);
 349                 }
 350
 351                 /* XXX this probably should exclude REQACK'd caps from capadd/capdel, but keep old behaviour for now */
 352                 if(HasCapabilityFlag(cap, CLICAP_FLAGS_REQACK))
 353                 {
 354                         strcat(pbuf[i], "~");
 355                         plen++;
 356                 }
 357
 358                 strcat(pbuf[i], cap->cap);
 359                 if (!finished) {
 360                         strcat(pbuf[i], " ");
 361                         plen += (namelen + 1);
 362                 }
 363         }
 364
 365         if(!finished)
 366         {
 367                 sendto_one(source_p, ":%s CAP %s NAK :%s",
 368                         me.name, EmptyString(source_p->name) ? "*" : source_p->name, arg);
 369                 return;
 370         }
 371
 372         if(i)
 373         {
 374                 sendto_one(source_p, "%s * :%s", buf, pbuf[0]);
 375                 sendto_one(source_p, "%s :%s", buf, pbuf[1]);
 376         }
 377         else
 378                 sendto_one(source_p, "%s :%s", buf, pbuf[0]);
 379
 380         source_p->localClient->caps |= capadd;
 381         source_p->localClient->caps &= ~capdel;
 382 }
 383
 384 static struct clicap_cmd
 385 {
 386         const char *cmd;
 387         void (*func)(struct Client *source_p, const char *arg);
 388 } clicap_cmdlist[] = {
 389         /* This list *MUST* be in alphabetical order */
 390         { "ACK",        cap_ack         },
 391         { "END",        cap_end         },
 392         { "LIST",       cap_list        },
 393         { "LS",         cap_ls          },
 394         { "REQ",        cap_req         },
 395 };
 396
 397 static int
 398 clicap_cmd_search(const char *command, struct clicap_cmd *entry)
 399 {
 400         return irccmp(command, entry->cmd);
 401 }
 402
 403 static void
 404 m_cap(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
 405 {
 406         struct clicap_cmd *cmd;
 407
 408         if(!(cmd = bsearch(parv[1], clicap_cmdlist,
 409                                 sizeof(clicap_cmdlist) / sizeof(struct clicap_cmd),
 410                                 sizeof(struct clicap_cmd), (bqcmp) clicap_cmd_search)))
 411         {
 412                 sendto_one(source_p, form_str(ERR_INVALIDCAPCMD),
 413                                 me.name, EmptyString(source_p->name) ? "*" : source_p->name,
 414                                 parv[1]);
 415                 return;
 416         }
 417
 418         (cmd->func)(source_p, parv[2]);
 419 }