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);
}

/*
 *
 *      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->name, 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->connection->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 *const 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;
        sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
                             "Fake direction: dropped message from %s[%s] via %s",
                             from->name, from->from->name,
                             get_client_name(client_p, SHOW_IP));
        sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
                             "Fake direction: dropped message fro %s[%s] via %s",
                             from->name, from->from->name,
                             get_client_name(client_p, MASK_IP));
        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 length = 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;
    length = bufend - ((s) ? s : ch);
    msg_ptr->bytes += length;
  }

  /*
   * 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 single parameter--can include blanks also. */
         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 *const 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:	4926
Committed:	Tue Nov 25 16:43:49 2014 UTC (10 years, 9 months ago) by michael
Content type:	text/x-csrc
File size:	18722 byte(s)
Log Message:	- parse.c: get rid of parse_cancel_clients()
#	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	/*
134	*
135	* parc number of arguments ('sender' counted as one!)
136	* parv[0] pointer to 'sender' (may point to empty string) (not used)
137	* parv[1]..parv[parc-1]
138	* pointers to additional parameters, this is a NULL
139	* terminated list (parv[parc] == NULL).
140	*
141	* WARNING
142	* Numerics are mostly error reports. If there is something
143	* wrong with the message, just DROP it! Don't even think of
144	* sending back a neat error message -- big danger of creating
145	* a ping pong error message...
146	*
147	* Rewritten by Nemesi, Jan 1999, to support numeric nicks in parv[1]
148	*
149	* Called when we get a numeric message from a remote _server_ and we are
150	* supposed to forward it somewhere. Note that we always ignore numerics sent
151	* to 'me' and simply drop the message if we can't handle with this properly:
152	* the savvy approach is NEVER generate an error in response to an... error :)
153	*/
154	static void
155	parse_handle_numeric(unsigned int numeric, struct Client source_p, int parc, char parv[])
156	{
157	struct Client *target_p = NULL;
158	struct Channel *chptr = NULL;
159
160	/*
161	* Avoid trash, we need it to come from a server and have a target
162	*/
163	if (parc < 2 \|\| !IsServer(source_p))
164	return;
165
166	/*
167	* Who should receive this message ? Will we do something with it ?
168	* Note that we use findUser functions, so the target can't be neither
169	* a server, nor a channel (?) nor a list of targets (?) .. u2.10
170	* should never generate numeric replies to non-users anyway
171	* Ahem... it can be a channel actually, csc bots use it :\ --Nem
172	*/
173	if (IsChanPrefix(*parv[1]))
174	chptr = hash_find_channel(parv[1]);
175	else
176	target_p = find_person(source_p, parv[1]);
177
178	if (((!target_p) \|\| (target_p->from == source_p->from)) && !chptr)
179	return;
180
181	/*
182	* Remap low number numerics, not that I understand WHY.. --Nemesi
183	*/
184	/*
185	* Numerics below 100 talk about the current 'connection', you're not
186	* connected to a remote server so it doesn't make sense to send them
187	* remotely - but the information they contain may be useful, so we
188	* remap them up. Weird, but true. -- Isomer
189	*/
190	if (numeric < 100)
191	numeric += 100;
192
193	if (target_p)
194	{
195	/* Fake it for server hiding, if it's our client */
196	if ((ConfigServerHide.hide_servers \|\| IsHidden(source_p)) && MyConnect(target_p) &&
197	!HasUMode(target_p, UMODE_OPER))
198	sendto_one_numeric(target_p, &me, numeric\|SND_EXPLICIT, "%s", parv[2]);
199	else
200	sendto_one_numeric(target_p, source_p, numeric\|SND_EXPLICIT, "%s", parv[2]);
201	}
202	else
203	sendto_channel_butone(source_p, source_p, chptr, 0, "%u %s %s",
204	numeric, chptr->name, parv[2]);
205	}
206
207	/* handle_command()
208	*
209	* inputs - pointer to message block
210	* - pointer to client
211	* - pointer to client message is from
212	* - count of number of args
213	* - pointer to argv[] array
214	* output - -1 if error from server
215	* side effects -
216	*/
217	static void
218	parse_handle_command(struct Message mptr, struct Client source_p,
219	unsigned int i, char *para[])
220	{
221	if (IsServer(source_p->from))
222	++mptr->rcount;
223
224	++mptr->count;
225
226	/* Check right amount of parameters is passed... --is */
227	if (i < mptr->args_min)
228	sendto_one_numeric(source_p, &me, ERR_NEEDMOREPARAMS, mptr->cmd);
229	else
230	mptr->handlers[source_p->from->handler](source_p, i, para);
231	}
232
233	/*
234	* parse a buffer.
235	*
236	* NOTE: parse() should not be called recusively by any other functions!
237	*/
238	void
239	parse(struct Client client_p, char pbuffer, char *bufend)
240	{
241	struct Client *from = client_p;
242	struct Message *msg_ptr = NULL;
243	char para[MAXPARA + 2]; / <command> + <parameters> + NULL */
244	char *ch = NULL;
245	char *s = NULL;
246	unsigned int numeric = 0;
247	unsigned int parc = 0;
248	unsigned int paramcount;
249
250	if (IsDefunct(client_p))
251	return;
252
253	assert(client_p->connection->fd.flags.open);
254	assert((bufend - pbuffer) < IRCD_BUFSIZE);
255
256	for (ch = pbuffer; ch == ' '; ++ch) / Skip spaces */
257	;
258
259	if (*ch == ':')
260	{
261	/*
262	* Copy the prefix to 'sender' assuming it terminates
263	* with SPACE (or NULL, which is an error, though).
264	*/
265	const char *const sender = ++ch;
266
267	if ((s = strchr(ch, ' ')))
268	{
269	*s = '\0';
270	ch = ++s;
271	}
272
273	if (*sender && IsServer(client_p))
274	{
275	if ((from = hash_find_id(sender)) == NULL)
276	from = hash_find_client(sender);
277
278	/*
279	* Hmm! If the client corresponding to the prefix is not found--what is
280	* the correct action??? Now, I will ignore the message (old IRC just
281	* let it through as if the prefix just wasn't there...) --msa
282	*/
283	if (from == NULL)
284	{
285	++ServerStats.is_unpf;
286	parse_remove_unknown(client_p, sender, pbuffer);
287	return;
288	}
289
290	if (from->from != client_p)
291	{
292	++ServerStats.is_wrdi;
293	sendto_realops_flags(UMODE_DEBUG, L_ADMIN, SEND_NOTICE,
294	"Fake direction: dropped message from %s[%s] via %s",
295	from->name, from->from->name,
296	get_client_name(client_p, SHOW_IP));
297	sendto_realops_flags(UMODE_DEBUG, L_OPER, SEND_NOTICE,
298	"Fake direction: dropped message fro %s[%s] via %s",
299	from->name, from->from->name,
300	get_client_name(client_p, MASK_IP));
301	return;
302	}
303	}
304
305	while (*ch == ' ')
306	++ch;
307	}
308
309	if (*ch == '\0')
310	{
311	++ServerStats.is_empt;
312	return;
313	}
314
315	/*
316	* Extract the command code from the packet. Point s to the end
317	* of the command code and calculate the length using pointer
318	* arithmetic. Note: only need length for numerics and all
319	* numerics must have parameters and thus a space after the command
320	* code. -avalon
321	*/
322
323	/* EOB is 3 characters long but is not a numeric */
324	if ((ch + 3) == ' ' && / Ok, let's see if it's a possible numeric */
325	IsDigit(ch) && IsDigit((ch + 1)) && IsDigit(*(ch + 2)))
326	{
327	numeric = (ch - '0') 100 + ((ch + 1) - '0') 10 + (*(ch + 2) - '0');
328	paramcount = 2; /* Destination, and the rest of it */
329	++ServerStats.is_num;
330	s = ch + 3; /* I know this is ' ' from above if */
331	s++ = '\0'; / Blow away the ' ', and point s to next part */
332	}
333	else
334	{
335	unsigned int length = 0;
336
337	if ((s = strchr(ch, ' ')))
338	*s++ = '\0';
339
340	if ((msg_ptr = find_command(ch)) == NULL)
341	{
342	/*
343	* Note: Give error message only to recognized
344	* persons. It's a nightmare situation to have
345	* two programs sending "Unknown command"'s or
346	* equivalent to each other at full blast....
347	* If it has got to person state, it at least
348	* seems to be well behaving. Perhaps this message
349	* should never be generated, though... --msa
350	* Hm, when is the buffer empty -- if a command
351	* code has been found ?? -Armin
352	*/
353	if (*pbuffer)
354	if (IsClient(from))
355	sendto_one_numeric(from, &me, ERR_UNKNOWNCOMMAND, ch);
356
357	++ServerStats.is_unco;
358	return;
359	}
360
361	assert(msg_ptr->cmd);
362
363	paramcount = msg_ptr->args_max;
364	length = bufend - ((s) ? s : ch);
365	msg_ptr->bytes += length;
366	}
367
368	/*
369	* Must the following loop really be so devious? On surface it
370	* splits the message to parameters from blank spaces. But, if
371	* paramcount has been reached, the rest of the message goes into
372	* this last parameter (about same effect as ":" has...) --msa
373	*/
374
375	/* Note initially true: s == NULL \|\| (s - 1) == '\0' !! /
376
377	para[parc] = ch;
378
379	if (msg_ptr && (msg_ptr->flags & MFLG_EXTRA))
380	{
381	/*
382	* XXX: This will have to go away after the command handler rewrite
383	*/
384	para[++parc] = msg_ptr->extra;
385	}
386
387	if (s)
388	{
389	if (paramcount > MAXPARA)
390	paramcount = MAXPARA;
391
392	while (1)
393	{
394	while (*s == ' ')
395	*s++ = '\0';
396
397	if (*s == '\0')
398	break;
399
400	if (*s == ':')
401	{
402	/* The rest is single parameter--can include blanks also. */
403	para[++parc] = s + (!numeric); /* Keep the colon if it's a numeric */
404	break;
405	}
406
407	para[++parc] = s;
408
409	if (parc >= paramcount)
410	break;
411
412	while (s && s != ' ')
413	++s;
414	}
415	}
416
417	para[++parc] = NULL;
418
419	if (msg_ptr)
420	parse_handle_command(msg_ptr, from, parc, para);
421	else
422	parse_handle_numeric(numeric, from, parc, para);
423	}
424
425	/* add_msg_element()
426	*
427	* inputs - pointer to MessageTree
428	* - pointer to Message to add for given command
429	* - pointer to current portion of command being added
430	* output - NONE
431	* side effects - recursively build the Message Tree ;-)
432	*/
433	/*
434	* How this works.
435	*
436	* The code first checks to see if its reached the end of the command
437	* If so, that struct MessageTree has a msg pointer updated and the links
438	* count incremented, since a msg pointer is a reference.
439	* Then the code descends recursively, building the trie.
440	* If a pointer index inside the struct MessageTree is NULL a new
441	* child struct MessageTree has to be allocated.
442	* The links (reference count) is incremented as they are created
443	* in the parent.
444	*/
445	static void
446	add_msg_element(struct MessageTree mtree_p, struct Message msg_p,
447	const char *cmd)
448	{
449	struct MessageTree *ntree_p = NULL;
450
451	if (*cmd == '\0')
452	{
453	mtree_p->msg = msg_p;
454	mtree_p->links++; /* Have msg pointer, so up ref count */
455	}
456	else
457	{
458	/*
459	* *cmd & (MAXPTRLEN-1)
460	* convert the char pointed to at *cmd from ASCII to an integer
461	* between 0 and MAXPTRLEN.
462	* Thus 'A' -> 0x1 'B' -> 0x2 'c' -> 0x3 etc.
463	*/
464	if ((ntree_p = mtree_p->pointers[*cmd & (MAXPTRLEN - 1)]) == NULL)
465	{
466	ntree_p = MyCalloc(sizeof(struct MessageTree));
467	mtree_p->pointers[*cmd & (MAXPTRLEN - 1)] = ntree_p;
468
469	mtree_p->links++; /* Have new pointer, so up ref count */
470	}
471
472	add_msg_element(ntree_p, msg_p, cmd + 1);
473	}
474	}
475
476	/* del_msg_element()
477	*
478	* inputs - Pointer to MessageTree to delete from
479	* - pointer to command name to delete
480	* output - NONE
481	* side effects - recursively deletes a token from the Message Tree ;-)
482	*/
483	/*
484	* How this works.
485	*
486	* Well, first off, the code recursively descends into the trie
487	* until it finds the terminating letter of the command being removed.
488	* Once it has done that, it marks the msg pointer as NULL then
489	* reduces the reference count on that allocated struct MessageTree
490	* since a command counts as a reference.
491	*
492	* Then it pops up the recurse stack. As it comes back up the recurse
493	* The code checks to see if the child now has no pointers or msg
494	* i.e. the links count has gone to zero. If it's no longer used, the
495	* child struct MessageTree can be deleted. The parent reference
496	* to this child is then removed and the parents link count goes down.
497	* Thus, we continue to go back up removing all unused MessageTree(s)
498	*/
499	static void
500	del_msg_element(struct MessageTree mtree_p, const char cmd)
501	{
502	struct MessageTree *ntree_p = NULL;
503
504	/*
505	* In case this is called for a nonexistent command
506	* check that there is a msg pointer here, else links-- goes -ve
507	* -db
508	*/
509	if (*cmd == '\0' && mtree_p->msg)
510	{
511	mtree_p->msg = NULL;
512	mtree_p->links--;
513	}
514	else
515	{
516	if ((ntree_p = mtree_p->pointers[*cmd & (MAXPTRLEN - 1)]))
517	{
518	del_msg_element(ntree_p, cmd + 1);
519
520	if (ntree_p->links == 0)
521	{
522	mtree_p->pointers[*cmd & (MAXPTRLEN - 1)] = NULL;
523	mtree_p->links--;
524	MyFree(ntree_p);
525	}
526	}
527	}
528	}
529
530	/* msg_tree_parse()
531	*
532	* inputs - Pointer to command to find
533	* - Pointer to MessageTree root
534	* output - Find given command returning Message * if found NULL if not
535	* side effects - none
536	*/
537	static struct Message *
538	msg_tree_parse(const char *cmd)
539	{
540	struct MessageTree *mtree = &msg_tree;
541
542	assert(cmd && *cmd);
543
544	while (IsAlpha(cmd) && (mtree = mtree->pointers[cmd & (MAXPTRLEN - 1)]))
545	if (*++cmd == '\0')
546	return mtree->msg;
547
548	return NULL;
549	}
550
551	/* mod_add_cmd()
552	*
553	* inputs - pointer to struct Message
554	* output - none
555	* side effects - load this one command name
556	*/
557	void
558	mod_add_cmd(struct Message *msg)
559	{
560	assert(msg && msg->cmd);
561
562	/* Command already added? */
563	if (msg_tree_parse(msg->cmd))
564	return;
565
566	add_msg_element(&msg_tree, msg, msg->cmd);
567	}
568
569	/* mod_del_cmd()
570	*
571	* inputs - pointer to struct Message
572	* output - none
573	* side effects - unload this one command name
574	*/
575	void
576	mod_del_cmd(struct Message *msg)
577	{
578	assert(msg && msg->cmd);
579
580	if (!msg_tree_parse(msg->cmd))
581	return;
582
583	del_msg_element(&msg_tree, msg->cmd);
584	}
585
586	/* find_command()
587	*
588	* inputs - command name
589	* output - pointer to struct Message
590	* side effects - none
591	*/
592	struct Message *
593	find_command(const char *cmd)
594	{
595	return msg_tree_parse(cmd);
596	}
597
598	static void
599	recurse_report_messages(struct Client source_p, const struct MessageTree mtree)
600	{
601	if (mtree->msg)
602	sendto_one_numeric(source_p, &me, RPL_STATSCOMMANDS,
603	mtree->msg->cmd,
604	mtree->msg->count, mtree->msg->bytes,
605	mtree->msg->rcount);
606
607	for (unsigned int i = 0; i < MAXPTRLEN; ++i)
608	if (mtree->pointers[i])
609	recurse_report_messages(source_p, mtree->pointers[i]);
610	}
611
612	/* report_messages()
613	*
614	* inputs - pointer to client to report to
615	* output - NONE
616	* side effects - client is shown list of commands
617	*/
618	void
619	report_messages(struct Client *source_p)
620	{
621	const struct MessageTree *const mtree = &msg_tree;
622
623	for (unsigned int i = 0; i < MAXPTRLEN; ++i)
624	if (mtree->pointers[i])
625	recurse_report_messages(source_p, mtree->pointers[i]);
626	}
627
628	/* m_not_oper()
629	* inputs -
630	* output -
631	* side effects - just returns a nastyogram to given user
632	*/
633	int
634	m_not_oper(struct Client source_p, int parc, char parv[])
635	{
636	sendto_one_numeric(source_p, &me, ERR_NOPRIVILEGES);
637	return 0;
638	}
639
640	int
641	m_unregistered(struct Client source_p, int parc, char parv[])
642	{
643	sendto_one_numeric(source_p, &me, ERR_NOTREGISTERED);
644	return 0;
645	}
646
647	int
648	m_registered(struct Client source_p, int parc, char parv[])
649	{
650	sendto_one_numeric(source_p, &me, ERR_ALREADYREGISTRED);
651	return 0;
652	}
653
654	int
655	m_ignore(struct Client source_p, int parc, char parv[])
656	{
657	return 0;
658	}