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         static char buf_prefix[DATALEN + 1];
 156         static char buf_list[DATALEN + 1];
 157         const char *str_cont = " * :";
 158         const char *str_final = " :";
 159         int len_prefix;
 160         int max_list;
 161         struct CapabilityEntry *entry;
 162         rb_dictionary_iter iter;
 163
 164         buf_prefix[0] = '\0';
 165         len_prefix = rb_snprintf_try_append(buf_prefix, sizeof(buf_prefix),
 166                         ":%s CAP %s %s",
 167                         me.name,
 168                         EmptyString(source_p->name) ? "*" : source_p->name,
 169                         subcmd);
 170
 171         /* shortcut, nothing to do */
 172         if (flags == -1 || len_prefix < 0) {
 173                 sendto_one(source_p, "%s%s", buf_prefix, str_final);
 174                 return;
 175         }
 176
 177         buf_list[0] = '\0';
 178         max_list = sizeof(buf_prefix) - len_prefix - strlen(str_cont);
 179
 180         for (int pass = 0; pass < 2; pass++)
 181         RB_DICTIONARY_FOREACH(entry, &iter, cli_capindex->cap_dict) {
 182                 struct ClientCapability *clicap = entry->ownerdata;
 183                 const char *data = NULL;
 184
 185                 if (pass == 0 && !HasCapabilityFlag(entry, CLICAP_FLAGS_PRIORITY))
 186                         continue;
 187                 else if (pass == 1 && HasCapabilityFlag(entry, CLICAP_FLAGS_PRIORITY))
 188                         continue;
 189
 190                 if (flags && !IsCapableEntry(source_p, entry))
 191                         continue;
 192
 193                 if (!clicap_visible(source_p, entry))
 194                         continue;
 195
 196                 if (!flags && (source_p->flags & FLAGS_CLICAP_DATA) && clicap != NULL && clicap->data != NULL)
 197                         data = clicap->data(source_p);
 198
 199                 for (int attempts = 0; attempts < 2; attempts++) {
 200                         if (rb_snprintf_try_append(buf_list, max_list, "%s%s%s%s",
 201                                         buf_list[0] == '\0' ? "" : " ", /* space between caps */
 202                                         entry->cap,
 203                                         data != NULL ? "=" : "", /* '=' between cap and data */
 204                                         data != NULL ? data : "") < 0
 205                                         && buf_list[0] != '\0') {
 206
 207                                 if (!(source_p->flags & FLAGS_CLICAP_DATA)) {
 208                                         /* the client doesn't support multiple lines */
 209                                         continue;
 210                                 }
 211
 212                                 /* doesn't fit in the buffer, output what we have */
 213                                 sendto_one(source_p, "%s%s%s", buf_prefix, str_cont, buf_list);
 214
 215                                 /* reset the buffer and go around the loop one more time */
 216                                 buf_list[0] = '\0';
 217                         } else {
 218                                 break;
 219                         }
 220                 }
 221         }
 222
 223         sendto_one(source_p, "%s%s%s", buf_prefix, str_final, buf_list);
 224 }
 225
 226 static void
 227 cap_ack(struct Client *source_p, const char *arg)
 228 {
 229         struct CapabilityEntry *cap;
 230         int capadd = 0, capdel = 0;
 231         int finished = 0, negate;
 232
 233         if(EmptyString(arg))
 234                 return;
 235
 236         for(cap = clicap_find(arg, &negate, &finished); cap;
 237             cap = clicap_find(NULL, &negate, &finished))
 238         {
 239                 /* sent an ACK for something they havent REQd */
 240                 if(!IsCapableEntry(source_p, cap))
 241                         continue;
 242
 243                 if(negate)
 244                 {
 245                         /* dont let them ack something sticky off */
 246                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 247                                 continue;
 248
 249                         capdel |= (1 << cap->value);
 250                 }
 251                 else
 252                         capadd |= (1 << cap->value);
 253         }
 254
 255         source_p->localClient->caps |= capadd;
 256         source_p->localClient->caps &= ~capdel;
 257 }
 258
 259 static void
 260 cap_end(struct Client *source_p, const char *arg)
 261 {
 262         if(IsRegistered(source_p))
 263                 return;
 264
 265         source_p->flags &= ~FLAGS_CLICAP;
 266
 267         if(source_p->name[0] && source_p->flags & FLAGS_SENTUSER)
 268         {
 269                 register_local_user(source_p, source_p);
 270         }
 271 }
 272
 273 static void
 274 cap_list(struct Client *source_p, const char *arg)
 275 {
 276         /* list of what theyre currently using */
 277         clicap_generate(source_p, "LIST",
 278                         source_p->localClient->caps ? source_p->localClient->caps : -1);
 279 }
 280
 281 static void
 282 cap_ls(struct Client *source_p, const char *arg)
 283 {
 284         int caps_version = 301;
 285
 286         if(!IsRegistered(source_p))
 287                 source_p->flags |= FLAGS_CLICAP;
 288
 289         if (!EmptyString(arg)) {
 290                 caps_version = atoi(arg);
 291         }
 292
 293         if (caps_version >= 302) {
 294                 source_p->flags |= FLAGS_CLICAP_DATA;
 295                 source_p->localClient->caps |= CLICAP_CAP_NOTIFY;
 296         }
 297
 298         /* list of what we support */
 299         clicap_generate(source_p, "LS", 0);
 300 }
 301
 302 static void
 303 cap_req(struct Client *source_p, const char *arg)
 304 {
 305         char ack_buf[DATALEN+1];
 306         struct CapabilityEntry *cap;
 307         int capadd = 0, capdel = 0;
 308         int finished = 0, negate;
 309         int ret;
 310         hook_data_cap_change hdata;
 311
 312         if(!IsRegistered(source_p))
 313                 source_p->flags |= FLAGS_CLICAP;
 314
 315         if(EmptyString(arg))
 316                 return;
 317
 318         ret = snprintf(ack_buf, sizeof ack_buf, ":%s CAP %s ACK :%s",
 319                         me.name, EmptyString(source_p->name)? "*" : source_p->name, arg);
 320
 321         if (ret < 0 || ret > DATALEN)
 322         {
 323                 sendto_one(source_p, ":%s CAP %s NAK :%s",
 324                         me.name, EmptyString(source_p->name) ? "*" : source_p->name, arg);
 325                 return;
 326         }
 327
 328         for(cap = clicap_find(arg, &negate, &finished); cap;
 329             cap = clicap_find(NULL, &negate, &finished))
 330         {
 331                 if(negate)
 332                 {
 333                         if(HasCapabilityFlag(cap, CLICAP_FLAGS_STICKY))
 334                         {
 335                                 finished = 0;
 336                                 break;
 337                         }
 338
 339                         capdel |= (1 << cap->value);
 340                 }
 341                 else
 342                 {
 343                         if (!clicap_visible(source_p, cap))
 344                         {
 345                                 finished = 0;
 346                                 break;
 347                         }
 348
 349                         capadd |= (1 << cap->value);
 350                 }
 351
 352         }
 353
 354         if(!finished)
 355         {
 356                 sendto_one(source_p, ":%s CAP %s NAK :%s",
 357                         me.name, EmptyString(source_p->name) ? "*" : source_p->name, arg);
 358                 return;
 359         }
 360
 361         sendto_one(source_p, "%s", ack_buf);
 362
 363         hdata.client = source_p;
 364         hdata.oldcaps = source_p->localClient->caps;
 365         hdata.add = capadd;
 366         hdata.del = capdel;
 367
 368         source_p->localClient->caps |= capadd;
 369         source_p->localClient->caps &= ~capdel;
 370
 371         call_hook(h_cap_change, &hdata);
 372 }
 373
 374 static struct clicap_cmd
 375 {
 376         const char *cmd;
 377         void (*func)(struct Client *source_p, const char *arg);
 378 } clicap_cmdlist[] = {
 379         /* This list *MUST* be in alphabetical order */
 380         { "ACK",        cap_ack         },
 381         { "END",        cap_end         },
 382         { "LIST",       cap_list        },
 383         { "LS",         cap_ls          },
 384         { "REQ",        cap_req         },
 385 };
 386
 387 static int
 388 clicap_cmd_search(const char *command, struct clicap_cmd *entry)
 389 {
 390         return irccmp(command, entry->cmd);
 391 }
 392
 393 static void
 394 m_cap(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
 395 {
 396         struct clicap_cmd *cmd;
 397
 398         if(!(cmd = bsearch(parv[1], clicap_cmdlist,
 399                                 sizeof(clicap_cmdlist) / sizeof(struct clicap_cmd),
 400                                 sizeof(struct clicap_cmd), (bqcmp) clicap_cmd_search)))
 401         {
 402                 sendto_one(source_p, form_str(ERR_INVALIDCAPCMD),
 403                                 me.name, EmptyString(source_p->name) ? "*" : source_p->name,
 404                                 parv[1]);
 405                 return;
 406         }
 407
 408         (cmd->func)(source_p, parv[2]);
 409 }