trunk/src/parse.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2014 ircd-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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

/*! \file parse.c
 * \brief The message parser.
 * \version $Id$
 */

#include "stdinc.h"
#include "client.h"
#include "parse.h"
#include "channel.h"
#include "hash.h"
#include "irc_string.h"
#include "ircd.h"
#include "numeric.h"
#include "log.h"
#include "send.h"
#include "conf.h"
#include "memory.h"
#include "user.h"
#include "server.h"


/*
 * (based on orabidoo's parser code)
 *
 * This has always just been a trie. Look at volume III of Knuth ACP
 *
 *
 * ok, you start out with an array of pointers, each one corresponds
 * to a letter at the current position in the command being examined.
 *
 * so roughly you have this for matching 'trie' or 'tie'
 *
 * 't' points -> [MessageTree *] 'r' -> [MessageTree *] -> 'i'
 *   -> [MessageTree *] -> [MessageTree *] -> 'e' and matches
 *
 *                               'i' -> [MessageTree *] -> 'e' and matches
 *
 * BUGS (Limitations!)
 *
 * I designed this trie to parse ircd commands. Hence it currently
 * casefolds. This is trivial to fix by increasing MAXPTRLEN.
 * This trie also "folds" '{' etc. down. This means, the input to this
 * trie must be alpha tokens only. This again, is a limitation that
 * can be overcome by increasing MAXPTRLEN to include upper/lower case
 * at the expense of more memory. At the extreme end, you could make
 * MAXPTRLEN 128.
 *
 * This is also not a patricia trie. On short ircd tokens, this is
 * not likely going to matter.
 *
 * Diane Bruce (Dianora), June 6 2003
 */

/*
 * Must be a power of 2, and larger than 26 [a-z]|[A-Z]. It's used to allocate
 * the set of pointers at each node of the tree.
 * There are MAXPTRLEN pointers at each node. Obviously, there have to be more
 * pointers than ASCII letters. 32 is a nice number since there is then no need
 * to shift 'A'/'a' to base 0 index, at the expense of a few never used
 * pointers.
 * For a small parser like this, this is a good compromise and does
 * make it somewhat faster. - Dianora
 */
#define MAXPTRLEN 32


static struct MessageTree
{
  int links; /* Count of all pointers (including msg) at this node
              * used as reference count for deletion of _this_ node.
              */
  struct Message *msg;
  struct MessageTree *pointers[MAXPTRLEN];
} msg_tree;


/* remove_unknown()
 *
 * inputs       -
 * output       -
 * side effects -
 */
static void
parse_remove_unknown(struct Client *client_p, const char *lsender, char *lbuffer)
{
  /*
   * Do kill if it came from a server because it means there is a ghost
   * user on the other server which needs to be removed. -avalon
   * Tell opers about this. -Taner
   */
  /*
   * '[0-9]something'  is an ID      (KILL/SQUIT depending on its length)
   * 'nodots'          is a nickname (KILL)
   * 'no.dot.at.start' is a server   (SQUIT)
   */
  if ((IsDigit(*lsender) && strlen(lsender) <= IRC_MAXSID) || strchr(lsender, '.'))
  {
    sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
                         "Unknown prefix (%s) from %s, Squitting %s",
                         lbuffer, get_client_name(client_p, SHOW_IP), lsender);
    sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
                         "Unknown prefix (%s) from %s, Squitting %s",
                         lbuffer, client_p->name, lsender);
    sendto_one(client_p, ":%s SQUIT %s :(Unknown prefix (%s) from %s)",
               me.id, lsender, lbuffer, client_p->name);
  }
  else
    sendto_one(client_p, ":%s KILL %s :%s (Unknown Client)",
               me.id, lsender, me.name);
}

/* cancel_clients()
 *
 * inputs       -
 * output       -
 * side effects -
 */
static void
parse_cancel_clients(struct Client *client_p, struct Client *source_p, char *cmd)
{
  if (IsServer(source_p) || IsMe(source_p))
  {
    sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
                         "Message for %s[%s] from %s",
                         source_p->name, source_p->from->name,
                         get_client_name(client_p, SHOW_IP));
    sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
                         "Message for %s[%s] from %s",
                         source_p->name, source_p->from->name,
                         get_client_name(client_p, MASK_IP));
    sendto_realops_flags(UMODE_DEBUG, L_ALL, SEND_NOTICE,
                         "Not dropping server %s (%s) for Fake Direction",
                         client_p->name, source_p->name);
    return;
  }

  sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
                       "Message for %s[%s@%s!%s] from %s (TS, ignored)",
                       source_p->name, source_p->username, source_p->host,
                       source_p->from->name, get_client_name(client_p, SHOW_IP));
  sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
                       "Message for %s[%s@%s!%s] from %s (TS, ignored)",
                       source_p->name, source_p->username, source_p->host,
                       source_p->from->name, get_client_name(client_p, MASK_IP));
}

/*
 *
 *      parc    number of arguments ('sender' counted as one!)
 *      parv[0] pointer to 'sender' (may point to empty string) (not used)
 *      parv[1]..parv[parc-1]
 *              pointers to additional parameters, this is a NULL
 *              terminated list (parv[parc] == NULL).
 *
 * *WARNING*
 *      Numerics are mostly error reports. If there is something
 *      wrong with the message, just *DROP* it! Don't even think of
 *      sending back a neat error message -- big danger of creating
 *      a ping pong error message...
 *
 * Rewritten by Nemesi, Jan 1999, to support numeric nicks in parv[1]
 *
 * Called when we get a numeric message from a remote _server_ and we are
 * supposed to forward it somewhere. Note that we always ignore numerics sent
 * to 'me' and simply drop the message if we can't handle with this properly:
 * the savvy approach is NEVER generate an error in response to an... error :)
 */
static void
parse_handle_numeric(unsigned int numeric, struct Client *source_p, int parc, char *parv[])
{
  struct Client *target_p = NULL;
  struct Channel *chptr = NULL;

  /*
   * Avoid trash, we need it to come from a server and have a target
   */
  if (parc < 2 || !IsServer(source_p))
    return;

  /*
   * Who should receive this message ? Will we do something with it ?
   * Note that we use findUser functions, so the target can't be neither
   * a server, nor a channel (?) nor a list of targets (?) .. u2.10
   * should never generate numeric replies to non-users anyway
   * Ahem... it can be a channel actually, csc bots use it :\ --Nem
   */
  if (IsChanPrefix(*parv[1]))
    chptr = hash_find_channel(parv[1]);
  else
    target_p = find_person(source_p, parv[1]);

  if (((!target_p) || (target_p->from == source_p->from)) && !chptr)
    return;

  /*
   * Remap low number numerics, not that I understand WHY.. --Nemesi
   */
  /*
   * Numerics below 100 talk about the current 'connection', you're not
   * connected to a remote server so it doesn't make sense to send them
   * remotely - but the information they contain may be useful, so we
   * remap them up. Weird, but true.  -- Isomer
   */
  if (numeric < 100)
    numeric += 100;

  if (target_p)
  {
    /* Fake it for server hiding, if it's our client */
    if ((ConfigServerHide.hide_servers || IsHidden(source_p)) && MyConnect(target_p) &&
        !HasUMode(target_p, UMODE_OPER))
      sendto_one_numeric(target_p, &me, numeric|SND_EXPLICIT, "%s", parv[2]);
    else
      sendto_one_numeric(target_p, source_p, numeric|SND_EXPLICIT, "%s", parv[2]);
  }
  else
    sendto_channel_butone(source_p, source_p, chptr, 0, "%u %s %s",
                          numeric, chptr->chname, parv[2]);
}

/* handle_command()
 *
 * inputs       - pointer to message block
 *              - pointer to client
 *              - pointer to client message is from
 *              - count of number of args
 *              - pointer to argv[] array
 * output       - -1 if error from server
 * side effects -
 */
static void
parse_handle_command(struct Message *mptr, struct Client *source_p,
                     unsigned int i, char *para[])
{
  if (IsServer(source_p->from))
    ++mptr->rcount;

  ++mptr->count;

  /* Check right amount of parameters is passed... --is */
  if (i < mptr->args_min)
    sendto_one_numeric(source_p, &me, ERR_NEEDMOREPARAMS, mptr->cmd);
  else
    mptr->handlers[source_p->from->handler](source_p, i, para);
}

/*
 * parse a buffer.
 *
 * NOTE: parse() should not be called recusively by any other functions!
 */
void
parse(struct Client *client_p, char *pbuffer, char *bufend)
{
  struct Client *from = client_p;
  struct Message *msg_ptr = NULL;
  char *para[MAXPARA + 2];  /* <command> + <parameters> + NULL */
  char *ch = NULL;
  char *s = NULL;
  unsigned int numeric = 0;
  unsigned int parc = 0;
  unsigned int paramcount;

  if (IsDefunct(client_p))
    return;

  assert(client_p->localClient->fd.flags.open);
  assert((bufend - pbuffer) < IRCD_BUFSIZE);

  for (ch = pbuffer; *ch == ' '; ++ch)  /* Skip spaces */
    ;

  if (*ch == ':')
  {
    /*
     * Copy the prefix to 'sender' assuming it terminates
     * with SPACE (or NULL, which is an error, though).
     */
    const char *sender = ++ch;

    if ((s = strchr(ch, ' ')))
    {
      *s = '\0';
      ch = ++s;
    }

    if (*sender && IsServer(client_p))
    {
      if ((from = hash_find_id(sender)) == NULL)
        from = hash_find_client(sender);

      /*
       * Hmm! If the client corresponding to the prefix is not found--what is
       * the correct action??? Now, I will ignore the message (old IRC just
       * let it through as if the prefix just wasn't there...) --msa
       */
      if (from == NULL)
      {
        ++ServerStats.is_unpf;
        parse_remove_unknown(client_p, sender, pbuffer);
        return;
      }

      if (from->from != client_p)
      {
        ++ServerStats.is_wrdi;
        parse_cancel_clients(client_p, from, pbuffer);
        return;
      }
    }

    while (*ch == ' ')
      ++ch;
  }

  if (*ch == '\0')
  {
    ++ServerStats.is_empt;
    return;
  }

  /*
   * Extract the command code from the packet. Point s to the end
   * of the command code and calculate the length using pointer
   * arithmetic. Note: only need length for numerics and *all*
   * numerics must have parameters and thus a space after the command
   * code. -avalon
   */

  /* EOB is 3 characters long but is not a numeric */
  if (*(ch + 3) == ' ' &&  /* Ok, let's see if it's a possible numeric */
      IsDigit(*ch) && IsDigit(*(ch + 1)) && IsDigit(*(ch + 2)))
  {
    numeric = (*ch - '0') * 100 + (*(ch + 1) - '0') * 10 + (*(ch + 2) - '0');
    paramcount = 2;  /* Destination, and the rest of it */
    ++ServerStats.is_num;
    s = ch + 3;  /* I know this is ' ' from above if */
    *s++ = '\0';  /* Blow away the ' ', and point s to next part */
  }
  else
  {
    unsigned int ii = 0;

    if ((s = strchr(ch, ' ')))
      *s++ = '\0';

    if ((msg_ptr = find_command(ch)) == NULL)
    {
      /*
       * Note: Give error message *only* to recognized
       * persons. It's a nightmare situation to have
       * two programs sending "Unknown command"'s or
       * equivalent to each other at full blast....
       * If it has got to person state, it at least
       * seems to be well behaving. Perhaps this message
       * should never be generated, though...  --msa
       * Hm, when is the buffer empty -- if a command
       * code has been found ?? -Armin
       */
      if (*pbuffer)
        if (IsClient(from))
          sendto_one_numeric(from, &me, ERR_UNKNOWNCOMMAND, ch);

      ++ServerStats.is_unco;
      return;
    }

    assert(msg_ptr->cmd);

    paramcount = msg_ptr->args_max;
    ii = bufend - ((s) ? s : ch);
    msg_ptr->bytes += ii;
  }

  /*
   * Must the following loop really be so devious? On surface it
   * splits the message to parameters from blank spaces. But, if
   * paramcount has been reached, the rest of the message goes into
   * this last parameter (about same effect as ":" has...) --msa
   */

  /* Note initially true: s == NULL || *(s - 1) == '\0' !! */

  para[parc] = ch;

  if (msg_ptr && (msg_ptr->flags & MFLG_EXTRA))
  {
    /*
     * XXX: This will have to go away after the command handler rewrite
     */
    para[++parc] = msg_ptr->extra;
  }

  if (s)
  {
    if (paramcount > MAXPARA)
      paramcount = MAXPARA;

    while (1)
    {
       while (*s == ' ')
         *s++ = '\0';

       if (*s == '\0')
         break;

       if (*s == ':')
       {
         /* The rest is a single parameter */
         para[++parc] = s + (!numeric);  /* Keep the colon if it's a numeric */
         break;
       }

       para[++parc] = s;

       if (parc >= paramcount)
         break;

       while (*s && *s != ' ')
         ++s;
    }
  }

  para[++parc] = NULL;

  if (msg_ptr)
    parse_handle_command(msg_ptr, from, parc, para);
  else
    parse_handle_numeric(numeric, from, parc, para);
}

/* add_msg_element()
 *
 * inputs       - pointer to MessageTree
 *              - pointer to Message to add for given command
 *              - pointer to current portion of command being added
 * output       - NONE
 * side effects - recursively build the Message Tree ;-)
 */
/*
 * How this works.
 *
 * The code first checks to see if its reached the end of the command
 * If so, that struct MessageTree has a msg pointer updated and the links
 * count incremented, since a msg pointer is a reference.
 * Then the code descends recursively, building the trie.
 * If a pointer index inside the struct MessageTree is NULL a new
 * child struct MessageTree has to be allocated.
 * The links (reference count) is incremented as they are created
 * in the parent.
 */
static void
add_msg_element(struct MessageTree *mtree_p, struct Message *msg_p,
                const char *cmd)
{
  struct MessageTree *ntree_p = NULL;

  if (*cmd == '\0')
  {
    mtree_p->msg = msg_p;
    mtree_p->links++;  /* Have msg pointer, so up ref count */
  }
  else
  {
    /*
     * *cmd & (MAXPTRLEN-1)
     * convert the char pointed to at *cmd from ASCII to an integer
     * between 0 and MAXPTRLEN.
     * Thus 'A' -> 0x1 'B' -> 0x2 'c' -> 0x3 etc.
     */
    if ((ntree_p = mtree_p->pointers[*cmd & (MAXPTRLEN - 1)]) == NULL)
    {
      ntree_p = MyCalloc(sizeof(struct MessageTree));
      mtree_p->pointers[*cmd & (MAXPTRLEN - 1)] = ntree_p;

      mtree_p->links++;  /* Have new pointer, so up ref count */
    }

    add_msg_element(ntree_p, msg_p, cmd + 1);
  }
}

/* del_msg_element()
 *
 * inputs       - Pointer to MessageTree to delete from
 *              - pointer to command name to delete
 * output       - NONE
 * side effects - recursively deletes a token from the Message Tree ;-)
 */
/*
 * How this works.
 *
 * Well, first off, the code recursively descends into the trie
 * until it finds the terminating letter of the command being removed.
 * Once it has done that, it marks the msg pointer as NULL then
 * reduces the reference count on that allocated struct MessageTree
 * since a command counts as a reference.
 *
 * Then it pops up the recurse stack. As it comes back up the recurse
 * The code checks to see if the child now has no pointers or msg
 * i.e. the links count has gone to zero. If it's no longer used, the
 * child struct MessageTree can be deleted. The parent reference
 * to this child is then removed and the parents link count goes down.
 * Thus, we continue to go back up removing all unused MessageTree(s)
 */
static void
del_msg_element(struct MessageTree *mtree_p, const char *cmd)
{
  struct MessageTree *ntree_p = NULL;

  /*
   * In case this is called for a nonexistent command
   * check that there is a msg pointer here, else links-- goes -ve
   * -db
   */
  if (*cmd == '\0' && mtree_p->msg)
  {
    mtree_p->msg = NULL;
    mtree_p->links--;
  }
  else
  {
    if ((ntree_p = mtree_p->pointers[*cmd & (MAXPTRLEN - 1)]))
    {
      del_msg_element(ntree_p, cmd + 1);

      if (ntree_p->links == 0)
      {
        mtree_p->pointers[*cmd & (MAXPTRLEN - 1)] = NULL;
        mtree_p->links--;
        MyFree(ntree_p);
      }
    }
  }
}

/* msg_tree_parse()
 *
 * inputs       - Pointer to command to find
 *              - Pointer to MessageTree root
 * output       - Find given command returning Message * if found NULL if not
 * side effects - none
 */
static struct Message *
msg_tree_parse(const char *cmd)
{
  struct MessageTree *mtree = &msg_tree;

  assert(cmd && *cmd);

  while (IsAlpha(*cmd) && (mtree = mtree->pointers[*cmd & (MAXPTRLEN - 1)]))
    if (*++cmd == '\0')
      return mtree->msg;

  return NULL;
}

/* mod_add_cmd()
 *
 * inputs       - pointer to struct Message
 * output       - none
 * side effects - load this one command name
 */
void
mod_add_cmd(struct Message *msg)
{
  assert(msg && msg->cmd);

  /* Command already added? */
  if (msg_tree_parse(msg->cmd))
    return;

  add_msg_element(&msg_tree, msg, msg->cmd);
}

/* mod_del_cmd()
 *
 * inputs       - pointer to struct Message
 * output       - none
 * side effects - unload this one command name
 */
void
mod_del_cmd(struct Message *msg)
{
  assert(msg && msg->cmd);

  if (!msg_tree_parse(msg->cmd))
    return;

  del_msg_element(&msg_tree, msg->cmd);
}

/* find_command()
 *
 * inputs       - command name
 * output       - pointer to struct Message
 * side effects - none
 */
struct Message *
find_command(const char *cmd)
{
  return msg_tree_parse(cmd);
}

static void
recurse_report_messages(struct Client *source_p, const struct MessageTree *mtree)
{
  if (mtree->msg)
    sendto_one_numeric(source_p, &me, RPL_STATSCOMMANDS,
                       mtree->msg->cmd,
                       mtree->msg->count, mtree->msg->bytes,
                       mtree->msg->rcount);

  for (unsigned int i = 0; i < MAXPTRLEN; ++i)
    if (mtree->pointers[i])
      recurse_report_messages(source_p, mtree->pointers[i]);
}

/* report_messages()
 *
 * inputs       - pointer to client to report to
 * output       - NONE
 * side effects - client is shown list of commands
 */
void
report_messages(struct Client *source_p)
{
  const struct MessageTree *mtree = &msg_tree;

  for (unsigned int i = 0; i < MAXPTRLEN; ++i)
    if (mtree->pointers[i])
      recurse_report_messages(source_p, mtree->pointers[i]);
}

/* m_not_oper()
 * inputs       -
 * output       -
 * side effects - just returns a nastyogram to given user
 */
int
m_not_oper(struct Client *source_p, int parc, char *parv[])
{
  sendto_one_numeric(source_p, &me, ERR_NOPRIVILEGES);
  return 0;
}

int
m_unregistered(struct Client *source_p, int parc, char *parv[])
{
  sendto_one_numeric(source_p, &me, ERR_NOTREGISTERED);
  return 0;
}

int
m_registered(struct Client *source_p, int parc, char *parv[])
{
  sendto_one_numeric(source_p, &me, ERR_ALREADYREGISTRED);
  return 0;
}

int
m_ignore(struct Client *source_p, int parc, char *parv[])
{
  return 0;
}
Revision:	4565
Committed:	Sun Aug 24 10:27:40 2014 UTC (11 years ago) by michael
Content type:	text/x-csrc
File size:	19680 byte(s)
Log Message:	- Update GPL 2 license headers
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 1997-2014 ircd-hybrid development team
5	*
6	* This program is free software; you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	* USA
20	*/
21
22	/*! \file parse.c
23	* \brief The message parser.
24	* \version $Id$
25	*/
26
27	#include "stdinc.h"
28	#include "client.h"
29	#include "parse.h"
30	#include "channel.h"
31	#include "hash.h"
32	#include "irc_string.h"
33	#include "ircd.h"
34	#include "numeric.h"
35	#include "log.h"
36	#include "send.h"
37	#include "conf.h"
38	#include "memory.h"
39	#include "user.h"
40	#include "server.h"
41
42
43	/*
44	* (based on orabidoo's parser code)
45	*
46	* This has always just been a trie. Look at volume III of Knuth ACP
47	*
48	*
49	* ok, you start out with an array of pointers, each one corresponds
50	* to a letter at the current position in the command being examined.
51	*
52	* so roughly you have this for matching 'trie' or 'tie'
53	*
54	* 't' points -> [MessageTree ] 'r' -> [MessageTree ] -> 'i'
55	* -> [MessageTree ] -> [MessageTree ] -> 'e' and matches
56	*
57	* 'i' -> [MessageTree *] -> 'e' and matches
58	*
59	* BUGS (Limitations!)
60	*
61	* I designed this trie to parse ircd commands. Hence it currently
62	* casefolds. This is trivial to fix by increasing MAXPTRLEN.
63	* This trie also "folds" '{' etc. down. This means, the input to this
64	* trie must be alpha tokens only. This again, is a limitation that
65	* can be overcome by increasing MAXPTRLEN to include upper/lower case
66	* at the expense of more memory. At the extreme end, you could make
67	* MAXPTRLEN 128.
68	*
69	* This is also not a patricia trie. On short ircd tokens, this is
70	* not likely going to matter.
71	*
72	* Diane Bruce (Dianora), June 6 2003
73	*/
74
75	/*
76	* Must be a power of 2, and larger than 26 [a-z]\|[A-Z]. It's used to allocate
77	* the set of pointers at each node of the tree.
78	* There are MAXPTRLEN pointers at each node. Obviously, there have to be more
79	* pointers than ASCII letters. 32 is a nice number since there is then no need
80	* to shift 'A'/'a' to base 0 index, at the expense of a few never used
81	* pointers.
82	* For a small parser like this, this is a good compromise and does
83	* make it somewhat faster. - Dianora
84	*/
85	#define MAXPTRLEN 32
86
87
88	static struct MessageTree
89	{
90	int links; /* Count of all pointers (including msg) at this node
91	* used as reference count for deletion of _this_ node.
92	*/
93	struct Message *msg;
94	struct MessageTree *pointers[MAXPTRLEN];
95	} msg_tree;
96
97
98	/* remove_unknown()
99	*
100	* inputs -
101	* output -
102	* side effects -
103	*/
104	static void
105	parse_remove_unknown(struct Client client_p, const char lsender, char *lbuffer)
106	{
107	/*
108	* Do kill if it came from a server because it means there is a ghost
109	* user on the other server which needs to be removed. -avalon
110	* Tell opers about this. -Taner
111	*/
112	/*
113	* '[0-9]something' is an ID (KILL/SQUIT depending on its length)
114	* 'nodots' is a nickname (KILL)
115	* 'no.dot.at.start' is a server (SQUIT)
116	*/
117	if ((IsDigit(*lsender) && strlen(lsender) <= IRC_MAXSID) \|\| strchr(lsender, '.'))
118	{
119	sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
120	"Unknown prefix (%s) from %s, Squitting %s",
121	lbuffer, get_client_name(client_p, SHOW_IP), lsender);
122	sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
123	"Unknown prefix (%s) from %s, Squitting %s",
124	lbuffer, client_p->name, lsender);
125	sendto_one(client_p, ":%s SQUIT %s :(Unknown prefix (%s) from %s)",
126	me.id, lsender, lbuffer, client_p->name);
127	}
128	else
129	sendto_one(client_p, ":%s KILL %s :%s (Unknown Client)",
130	me.id, lsender, me.name);
131	}
132
133	/* cancel_clients()
134	*
135	* inputs -
136	* output -
137	* side effects -
138	*/
139	static void
140	parse_cancel_clients(struct Client client_p, struct Client source_p, char *cmd)
141	{
142	if (IsServer(source_p) \|\| IsMe(source_p))
143	{
144	sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
145	"Message for %s[%s] from %s",
146	source_p->name, source_p->from->name,
147	get_client_name(client_p, SHOW_IP));
148	sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
149	"Message for %s[%s] from %s",
150	source_p->name, source_p->from->name,
151	get_client_name(client_p, MASK_IP));
152	sendto_realops_flags(UMODE_DEBUG, L_ALL, SEND_NOTICE,
153	"Not dropping server %s (%s) for Fake Direction",
154	client_p->name, source_p->name);
155	return;
156	}
157
158	sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
159	"Message for %s[%s@%s!%s] from %s (TS, ignored)",
160	source_p->name, source_p->username, source_p->host,
161	source_p->from->name, get_client_name(client_p, SHOW_IP));
162	sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
163	"Message for %s[%s@%s!%s] from %s (TS, ignored)",
164	source_p->name, source_p->username, source_p->host,
165	source_p->from->name, get_client_name(client_p, MASK_IP));
166	}
167
168	/*
169	*
170	* parc number of arguments ('sender' counted as one!)
171	* parv[0] pointer to 'sender' (may point to empty string) (not used)
172	* parv[1]..parv[parc-1]
173	* pointers to additional parameters, this is a NULL
174	* terminated list (parv[parc] == NULL).
175	*
176	* WARNING
177	* Numerics are mostly error reports. If there is something
178	* wrong with the message, just DROP it! Don't even think of
179	* sending back a neat error message -- big danger of creating
180	* a ping pong error message...
181	*
182	* Rewritten by Nemesi, Jan 1999, to support numeric nicks in parv[1]
183	*
184	* Called when we get a numeric message from a remote _server_ and we are
185	* supposed to forward it somewhere. Note that we always ignore numerics sent
186	* to 'me' and simply drop the message if we can't handle with this properly:
187	* the savvy approach is NEVER generate an error in response to an... error :)
188	*/
189	static void
190	parse_handle_numeric(unsigned int numeric, struct Client source_p, int parc, char parv[])
191	{
192	struct Client *target_p = NULL;
193	struct Channel *chptr = NULL;
194
195	/*
196	* Avoid trash, we need it to come from a server and have a target
197	*/
198	if (parc < 2 \|\| !IsServer(source_p))
199	return;
200
201	/*
202	* Who should receive this message ? Will we do something with it ?
203	* Note that we use findUser functions, so the target can't be neither
204	* a server, nor a channel (?) nor a list of targets (?) .. u2.10
205	* should never generate numeric replies to non-users anyway
206	* Ahem... it can be a channel actually, csc bots use it :\ --Nem
207	*/
208	if (IsChanPrefix(*parv[1]))
209	chptr = hash_find_channel(parv[1]);
210	else
211	target_p = find_person(source_p, parv[1]);
212
213	if (((!target_p) \|\| (target_p->from == source_p->from)) && !chptr)
214	return;
215
216	/*
217	* Remap low number numerics, not that I understand WHY.. --Nemesi
218	*/
219	/*
220	* Numerics below 100 talk about the current 'connection', you're not
221	* connected to a remote server so it doesn't make sense to send them
222	* remotely - but the information they contain may be useful, so we
223	* remap them up. Weird, but true. -- Isomer
224	*/
225	if (numeric < 100)
226	numeric += 100;
227
228	if (target_p)
229	{
230	/* Fake it for server hiding, if it's our client */
231	if ((ConfigServerHide.hide_servers \|\| IsHidden(source_p)) && MyConnect(target_p) &&
232	!HasUMode(target_p, UMODE_OPER))
233	sendto_one_numeric(target_p, &me, numeric\|SND_EXPLICIT, "%s", parv[2]);
234	else
235	sendto_one_numeric(target_p, source_p, numeric\|SND_EXPLICIT, "%s", parv[2]);
236	}
237	else
238	sendto_channel_butone(source_p, source_p, chptr, 0, "%u %s %s",
239	numeric, chptr->chname, parv[2]);
240	}
241
242	/* handle_command()
243	*
244	* inputs - pointer to message block
245	* - pointer to client
246	* - pointer to client message is from
247	* - count of number of args
248	* - pointer to argv[] array
249	* output - -1 if error from server
250	* side effects -
251	*/
252	static void
253	parse_handle_command(struct Message mptr, struct Client source_p,
254	unsigned int i, char *para[])
255	{
256	if (IsServer(source_p->from))
257	++mptr->rcount;
258
259	++mptr->count;
260
261	/* Check right amount of parameters is passed... --is */
262	if (i < mptr->args_min)
263	sendto_one_numeric(source_p, &me, ERR_NEEDMOREPARAMS, mptr->cmd);
264	else
265	mptr->handlers[source_p->from->handler](source_p, i, para);
266	}
267
268	/*
269	* parse a buffer.
270	*
271	* NOTE: parse() should not be called recusively by any other functions!
272	*/
273	void
274	parse(struct Client client_p, char pbuffer, char *bufend)
275	{
276	struct Client *from = client_p;
277	struct Message *msg_ptr = NULL;
278	char para[MAXPARA + 2]; / <command> + <parameters> + NULL */
279	char *ch = NULL;
280	char *s = NULL;
281	unsigned int numeric = 0;
282	unsigned int parc = 0;
283	unsigned int paramcount;
284
285	if (IsDefunct(client_p))
286	return;
287
288	assert(client_p->localClient->fd.flags.open);
289	assert((bufend - pbuffer) < IRCD_BUFSIZE);
290
291	for (ch = pbuffer; ch == ' '; ++ch) / Skip spaces */
292	;
293
294	if (*ch == ':')
295	{
296	/*
297	* Copy the prefix to 'sender' assuming it terminates
298	* with SPACE (or NULL, which is an error, though).
299	*/
300	const char *sender = ++ch;
301
302	if ((s = strchr(ch, ' ')))
303	{
304	*s = '\0';
305	ch = ++s;
306	}
307
308	if (*sender && IsServer(client_p))
309	{
310	if ((from = hash_find_id(sender)) == NULL)
311	from = hash_find_client(sender);
312
313	/*
314	* Hmm! If the client corresponding to the prefix is not found--what is
315	* the correct action??? Now, I will ignore the message (old IRC just
316	* let it through as if the prefix just wasn't there...) --msa
317	*/
318	if (from == NULL)
319	{
320	++ServerStats.is_unpf;
321	parse_remove_unknown(client_p, sender, pbuffer);
322	return;
323	}
324
325	if (from->from != client_p)
326	{
327	++ServerStats.is_wrdi;
328	parse_cancel_clients(client_p, from, pbuffer);
329	return;
330	}
331	}
332
333	while (*ch == ' ')
334	++ch;
335	}
336
337	if (*ch == '\0')
338	{
339	++ServerStats.is_empt;
340	return;
341	}
342
343	/*
344	* Extract the command code from the packet. Point s to the end
345	* of the command code and calculate the length using pointer
346	* arithmetic. Note: only need length for numerics and all
347	* numerics must have parameters and thus a space after the command
348	* code. -avalon
349	*/
350
351	/* EOB is 3 characters long but is not a numeric */
352	if ((ch + 3) == ' ' && / Ok, let's see if it's a possible numeric */
353	IsDigit(ch) && IsDigit((ch + 1)) && IsDigit(*(ch + 2)))
354	{
355	numeric = (ch - '0') 100 + ((ch + 1) - '0') 10 + (*(ch + 2) - '0');
356	paramcount = 2; /* Destination, and the rest of it */
357	++ServerStats.is_num;
358	s = ch + 3; /* I know this is ' ' from above if */
359	s++ = '\0'; / Blow away the ' ', and point s to next part */
360	}
361	else
362	{
363	unsigned int ii = 0;
364
365	if ((s = strchr(ch, ' ')))
366	*s++ = '\0';
367
368	if ((msg_ptr = find_command(ch)) == NULL)
369	{
370	/*
371	* Note: Give error message only to recognized
372	* persons. It's a nightmare situation to have
373	* two programs sending "Unknown command"'s or
374	* equivalent to each other at full blast....
375	* If it has got to person state, it at least
376	* seems to be well behaving. Perhaps this message
377	* should never be generated, though... --msa
378	* Hm, when is the buffer empty -- if a command
379	* code has been found ?? -Armin
380	*/
381	if (*pbuffer)
382	if (IsClient(from))
383	sendto_one_numeric(from, &me, ERR_UNKNOWNCOMMAND, ch);
384
385	++ServerStats.is_unco;
386	return;
387	}
388
389	assert(msg_ptr->cmd);
390
391	paramcount = msg_ptr->args_max;
392	ii = bufend - ((s) ? s : ch);
393	msg_ptr->bytes += ii;
394	}
395
396	/*
397	* Must the following loop really be so devious? On surface it
398	* splits the message to parameters from blank spaces. But, if
399	* paramcount has been reached, the rest of the message goes into
400	* this last parameter (about same effect as ":" has...) --msa
401	*/
402
403	/* Note initially true: s == NULL \|\| (s - 1) == '\0' !! /
404
405	para[parc] = ch;
406
407	if (msg_ptr && (msg_ptr->flags & MFLG_EXTRA))
408	{
409	/*
410	* XXX: This will have to go away after the command handler rewrite
411	*/
412	para[++parc] = msg_ptr->extra;
413	}
414
415	if (s)
416	{
417	if (paramcount > MAXPARA)
418	paramcount = MAXPARA;
419
420	while (1)
421	{
422	while (*s == ' ')
423	*s++ = '\0';
424
425	if (*s == '\0')
426	break;
427
428	if (*s == ':')
429	{
430	/* The rest is a single parameter */
431	para[++parc] = s + (!numeric); /* Keep the colon if it's a numeric */
432	break;
433	}
434
435	para[++parc] = s;
436
437	if (parc >= paramcount)
438	break;
439
440	while (s && s != ' ')
441	++s;
442	}
443	}
444
445	para[++parc] = NULL;
446
447	if (msg_ptr)
448	parse_handle_command(msg_ptr, from, parc, para);
449	else
450	parse_handle_numeric(numeric, from, parc, para);
451	}
452
453	/* add_msg_element()
454	*
455	* inputs - pointer to MessageTree
456	* - pointer to Message to add for given command
457	* - pointer to current portion of command being added
458	* output - NONE
459	* side effects - recursively build the Message Tree ;-)
460	*/
461	/*
462	* How this works.
463	*
464	* The code first checks to see if its reached the end of the command
465	* If so, that struct MessageTree has a msg pointer updated and the links
466	* count incremented, since a msg pointer is a reference.
467	* Then the code descends recursively, building the trie.
468	* If a pointer index inside the struct MessageTree is NULL a new
469	* child struct MessageTree has to be allocated.
470	* The links (reference count) is incremented as they are created
471	* in the parent.
472	*/
473	static void
474	add_msg_element(struct MessageTree mtree_p, struct Message msg_p,
475	const char *cmd)
476	{
477	struct MessageTree *ntree_p = NULL;
478
479	if (*cmd == '\0')
480	{
481	mtree_p->msg = msg_p;
482	mtree_p->links++; /* Have msg pointer, so up ref count */
483	}
484	else
485	{
486	/*
487	* *cmd & (MAXPTRLEN-1)
488	* convert the char pointed to at *cmd from ASCII to an integer
489	* between 0 and MAXPTRLEN.
490	* Thus 'A' -> 0x1 'B' -> 0x2 'c' -> 0x3 etc.
491	*/
492	if ((ntree_p = mtree_p->pointers[*cmd & (MAXPTRLEN - 1)]) == NULL)
493	{
494	ntree_p = MyCalloc(sizeof(struct MessageTree));
495	mtree_p->pointers[*cmd & (MAXPTRLEN - 1)] = ntree_p;
496
497	mtree_p->links++; /* Have new pointer, so up ref count */
498	}
499
500	add_msg_element(ntree_p, msg_p, cmd + 1);
501	}
502	}
503
504	/* del_msg_element()
505	*
506	* inputs - Pointer to MessageTree to delete from
507	* - pointer to command name to delete
508	* output - NONE
509	* side effects - recursively deletes a token from the Message Tree ;-)
510	*/
511	/*
512	* How this works.
513	*
514	* Well, first off, the code recursively descends into the trie
515	* until it finds the terminating letter of the command being removed.
516	* Once it has done that, it marks the msg pointer as NULL then
517	* reduces the reference count on that allocated struct MessageTree
518	* since a command counts as a reference.
519	*
520	* Then it pops up the recurse stack. As it comes back up the recurse
521	* The code checks to see if the child now has no pointers or msg
522	* i.e. the links count has gone to zero. If it's no longer used, the
523	* child struct MessageTree can be deleted. The parent reference
524	* to this child is then removed and the parents link count goes down.
525	* Thus, we continue to go back up removing all unused MessageTree(s)
526	*/
527	static void
528	del_msg_element(struct MessageTree mtree_p, const char cmd)
529	{
530	struct MessageTree *ntree_p = NULL;
531
532	/*
533	* In case this is called for a nonexistent command
534	* check that there is a msg pointer here, else links-- goes -ve
535	* -db
536	*/
537	if (*cmd == '\0' && mtree_p->msg)
538	{
539	mtree_p->msg = NULL;
540	mtree_p->links--;
541	}
542	else
543	{
544	if ((ntree_p = mtree_p->pointers[*cmd & (MAXPTRLEN - 1)]))
545	{
546	del_msg_element(ntree_p, cmd + 1);
547
548	if (ntree_p->links == 0)
549	{
550	mtree_p->pointers[*cmd & (MAXPTRLEN - 1)] = NULL;
551	mtree_p->links--;
552	MyFree(ntree_p);
553	}
554	}
555	}
556	}
557
558	/* msg_tree_parse()
559	*
560	* inputs - Pointer to command to find
561	* - Pointer to MessageTree root
562	* output - Find given command returning Message * if found NULL if not
563	* side effects - none
564	*/
565	static struct Message *
566	msg_tree_parse(const char *cmd)
567	{
568	struct MessageTree *mtree = &msg_tree;
569
570	assert(cmd && *cmd);
571
572	while (IsAlpha(cmd) && (mtree = mtree->pointers[cmd & (MAXPTRLEN - 1)]))
573	if (*++cmd == '\0')
574	return mtree->msg;
575
576	return NULL;
577	}
578
579	/* mod_add_cmd()
580	*
581	* inputs - pointer to struct Message
582	* output - none
583	* side effects - load this one command name
584	*/
585	void
586	mod_add_cmd(struct Message *msg)
587	{
588	assert(msg && msg->cmd);
589
590	/* Command already added? */
591	if (msg_tree_parse(msg->cmd))
592	return;
593
594	add_msg_element(&msg_tree, msg, msg->cmd);
595	}
596
597	/* mod_del_cmd()
598	*
599	* inputs - pointer to struct Message
600	* output - none
601	* side effects - unload this one command name
602	*/
603	void
604	mod_del_cmd(struct Message *msg)
605	{
606	assert(msg && msg->cmd);
607
608	if (!msg_tree_parse(msg->cmd))
609	return;
610
611	del_msg_element(&msg_tree, msg->cmd);
612	}
613
614	/* find_command()
615	*
616	* inputs - command name
617	* output - pointer to struct Message
618	* side effects - none
619	*/
620	struct Message *
621	find_command(const char *cmd)
622	{
623	return msg_tree_parse(cmd);
624	}
625
626	static void
627	recurse_report_messages(struct Client source_p, const struct MessageTree mtree)
628	{
629	if (mtree->msg)
630	sendto_one_numeric(source_p, &me, RPL_STATSCOMMANDS,
631	mtree->msg->cmd,
632	mtree->msg->count, mtree->msg->bytes,
633	mtree->msg->rcount);
634
635	for (unsigned int i = 0; i < MAXPTRLEN; ++i)
636	if (mtree->pointers[i])
637	recurse_report_messages(source_p, mtree->pointers[i]);
638	}
639
640	/* report_messages()
641	*
642	* inputs - pointer to client to report to
643	* output - NONE
644	* side effects - client is shown list of commands
645	*/
646	void
647	report_messages(struct Client *source_p)
648	{
649	const struct MessageTree *mtree = &msg_tree;
650
651	for (unsigned int i = 0; i < MAXPTRLEN; ++i)
652	if (mtree->pointers[i])
653	recurse_report_messages(source_p, mtree->pointers[i]);
654	}
655
656	/* m_not_oper()
657	* inputs -
658	* output -
659	* side effects - just returns a nastyogram to given user
660	*/
661	int
662	m_not_oper(struct Client source_p, int parc, char parv[])
663	{
664	sendto_one_numeric(source_p, &me, ERR_NOPRIVILEGES);
665	return 0;
666	}
667
668	int
669	m_unregistered(struct Client source_p, int parc, char parv[])
670	{
671	sendto_one_numeric(source_p, &me, ERR_NOTREGISTERED);
672	return 0;
673	}
674
675	int
676	m_registered(struct Client source_p, int parc, char parv[])
677	{
678	sendto_one_numeric(source_p, &me, ERR_ALREADYREGISTRED);
679	return 0;
680	}
681
682	int
683	m_ignore(struct Client source_p, int parc, char parv[])
684	{
685	return 0;
686	}