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 capbuflen = 0;
 158         int buflen;
 159         struct CapabilityEntry *entry;
 160         rb_dictionary_iter iter;
 161
 162         buflen = 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         RB_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 /* "=" between cap and data */;
 192
 193                 /* "<buf> * :<capbuf>-~=<cap><=><data> " */
 194                 if(buflen + 4 + capbuflen + 3 + caplen + 1 > DATALEN)
 195                 {
 196                         /* remove our trailing space -- if capbuflen == 0
 197                          * here, we didnt even succeed in adding one.
 198                          */
 199                         capbuf[capbuflen] = '\0';
 200
 201                         sendto_one(source_p, "%s * :%s", buf, capbuf);
 202
 203                         memset(capbuf, 0, sizeof capbuf);
 204                 }
 205
 206                 capbuflen = rb_snprintf_append(capbuf, sizeof capbuf, "%s%s%s ",
 207                                 entry->cap, data != NULL ? "=" : "", data != NULL ? data : "");
 208         }
 209
 210         /* remove trailing space */
 211         capbuf[capbuflen] = '\0';
 212
 213         sendto_one(source_p, "%s :%s", buf, capbuf);
 214 }
 215
 216 static void
 217 cap_ack(struct Client *source_p, const char *arg)
 218 {
 219         struct CapabilityEntry *cap;
 220         int capadd = 0, capdel = 0;
 221         int finished = 0, negate;
 222
 223         if(EmptyString(arg))
 224                 return;
 225
 226         for(cap = clicap_find(arg, &negate, &finished); cap;
 227             cap = clicap_find(NULL, &negate, &finished))
 228         {
 229                 /* sent an ACK for something they havent REQd */
 230                 if(!IsCapableEntry(source_p, cap))
 231                         continue;
 232
 233                 if(negate)
 234                 {
 235                         /* dont let them ack something sticky off */
 236                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 237                                 continue;
 238
 239                         capdel |= (1 << cap->value);
 240                 }
 241                 else
 242                         capadd |= (1 << cap->value);
 243         }
 244
 245         source_p->localClient->caps |= capadd;
 246         source_p->localClient->caps &= ~capdel;
 247 }
 248
 249 static void
 250 cap_end(struct Client *source_p, const char *arg)
 251 {
 252         if(IsRegistered(source_p))
 253                 return;
 254
 255         source_p->flags &= ~FLAGS_CLICAP;
 256
 257         if(source_p->name[0] && source_p->flags & FLAGS_SENTUSER)
 258         {
 259                 register_local_user(source_p, source_p);
 260         }
 261 }
 262
 263 static void
 264 cap_list(struct Client *source_p, const char *arg)
 265 {
 266         /* list of what theyre currently using */
 267         clicap_generate(source_p, "LIST",
 268                         source_p->localClient->caps ? source_p->localClient->caps : -1);
 269 }
 270
 271 static void
 272 cap_ls(struct Client *source_p, const char *arg)
 273 {
 274         if(!IsRegistered(source_p))
 275                 source_p->flags |= FLAGS_CLICAP;
 276
 277         if (arg != NULL && !strcmp(arg, "302"))
 278         {
 279                 source_p->flags |= FLAGS_CLICAP_DATA;
 280                 source_p->localClient->caps |= CLICAP_CAP_NOTIFY;
 281         }
 282
 283         /* list of what we support */
 284         clicap_generate(source_p, "LS", 0);
 285 }
 286
 287 static void
 288 cap_req(struct Client *source_p, const char *arg)
 289 {
 290         char buf[BUFSIZE];
 291         char pbuf[2][BUFSIZE];
 292         struct CapabilityEntry *cap;
 293         int buflen, plen;
 294         int i = 0;
 295         int capadd = 0, capdel = 0;
 296         int finished = 0, negate;
 297
 298         if(!IsRegistered(source_p))
 299                 source_p->flags |= FLAGS_CLICAP;
 300
 301         if(EmptyString(arg))
 302                 return;
 303
 304         buflen = snprintf(buf, sizeof(buf), ":%s CAP %s ACK",
 305                         me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 306
 307         pbuf[0][0] = '\0';
 308         plen = 0;
 309
 310         for(cap = clicap_find(arg, &negate, &finished); cap;
 311             cap = clicap_find(NULL, &negate, &finished))
 312         {
 313                 size_t namelen = strlen(cap->cap);
 314
 315                 /* filled the first array, but cant send it in case the
 316                  * request fails.  one REQ should never fill more than two
 317                  * buffers --fl
 318                  */
 319                 if(buflen + plen + namelen + 6 >= BUFSIZE)
 320                 {
 321                         pbuf[1][0] = '\0';
 322                         plen = 0;
 323                         i = 1;
 324                 }
 325
 326                 if(negate)
 327                 {
 328                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 329                         {
 330                                 finished = 0;
 331                                 break;
 332                         }
 333
 334                         strcat(pbuf[i], "-");
 335                         plen++;
 336
 337                         capdel |= (1 << cap->value);
 338                 }
 339                 else
 340                 {
 341                         if (!clicap_visible(source_p, cap))
 342                         {
 343                                 finished = 0;
 344                                 break;
 345                         }
 346
 347                         capadd |= (1 << cap->value);
 348                 }
 349
 350                 /* XXX this probably should exclude REQACK'd caps from capadd/capdel, but keep old behaviour for now */
 351                 if(HasCapabilityFlag(cap, CLICAP_FLAGS_REQACK))
 352                 {
 353                         strcat(pbuf[i], "~");
 354                         plen++;
 355                 }
 356
 357                 strcat(pbuf[i], cap->cap);
 358                 if (!finished) {
 359                         strcat(pbuf[i], " ");
 360                         plen += (namelen + 1);
 361                 }
 362         }
 363
 364         if(!finished)
 365         {
 366                 sendto_one(source_p, ":%s CAP %s NAK :%s",
 367                         me.name, EmptyString(source_p->name) ? "*" : source_p->name, arg);
 368                 return;
 369         }
 370
 371         if(i)
 372         {
 373                 sendto_one(source_p, "%s * :%s", buf, pbuf[0]);
 374                 sendto_one(source_p, "%s :%s", buf, pbuf[1]);
 375         }
 376         else
 377                 sendto_one(source_p, "%s :%s", buf, pbuf[0]);
 378
 379         source_p->localClient->caps |= capadd;
 380         source_p->localClient->caps &= ~capdel;
 381 }
 382
 383 static struct clicap_cmd
 384 {
 385         const char *cmd;
 386         void (*func)(struct Client *source_p, const char *arg);
 387 } clicap_cmdlist[] = {
 388         /* This list *MUST* be in alphabetical order */
 389         { "ACK",        cap_ack         },
 390         { "END",        cap_end         },
 391         { "LIST",       cap_list        },
 392         { "LS",         cap_ls          },
 393         { "REQ",        cap_req         },
 394 };
 395
 396 static int
 397 clicap_cmd_search(const char *command, struct clicap_cmd *entry)
 398 {
 399         return irccmp(command, entry->cmd);
 400 }
 401
 402 static void
 403 m_cap(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
 404 {
 405         struct clicap_cmd *cmd;
 406
 407         if(!(cmd = bsearch(parv[1], clicap_cmdlist,
 408                                 sizeof(clicap_cmdlist) / sizeof(struct clicap_cmd),
 409                                 sizeof(struct clicap_cmd), (bqcmp) clicap_cmd_search)))
 410         {
 411                 sendto_one(source_p, form_str(ERR_INVALIDCAPCMD),
 412                                 me.name, EmptyString(source_p->name) ? "*" : source_p->name,
 413                                 parv[1]);
 414                 return;
 415         }
 416
 417         (cmd->func)(source_p, parv[2]);
 418 }