trunk/src/hostmask.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 2001-2017 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 hostmask.c
 * \brief Code to efficiently find IP & hostmask based configs.
 * \version $Id$
 */

#include "stdinc.h"
#include "memory.h"
#include "ircd_defs.h"
#include "list.h"
#include "conf.h"
#include "hostmask.h"
#include "send.h"
#include "irc_string.h"
#include "ircd.h"


#define DigitParse(ch) do { \
                       if (ch >= '0' && ch <= '9') \
                         ch = ch - '0'; \
                       else if (ch >= 'A' && ch <= 'F') \
                         ch = ch - 'A' + 10; \
                       else if (ch >= 'a' && ch <= 'f') \
                         ch = ch - 'a' + 10; \
                       } while (0);

/* Hashtable stuff...now external as it's used in m_stats.c */
dlink_list atable[ATABLE_SIZE];

/* The mask parser/type determination code... */

/* int try_parse_v6_netmask(const char *, struct irc_ssaddr *, int *);
 * Input: A possible IPV6 address as a string.
 * Output: An integer describing whether it is an IPV6 or hostmask,
 *         an address(if it is IPV6), a bitlength(if it is IPV6).
 * Side effects: None
 * Comments: Called from parse_netmask
 */
static int
try_parse_v6_netmask(const char *text, struct irc_ssaddr *addr, int *b)
{
  char c;
  int d[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  int dp = 0;
  int nyble = 4;
  int finsert = -1;
  int bits = 128;
  int deficit = 0;
  short dc[8];
  struct sockaddr_in6 *const v6 = (struct sockaddr_in6 *)addr;

  for (const char *p = text; (c = *p); ++p)
  {
    if (IsXDigit(c))
    {
      if (nyble == 0)
        return HM_HOST;
      DigitParse(c);
      d[dp] |= c << (4 * --nyble);
    }
    else if (c == ':')
    {
      if (p > text && *(p - 1) == ':')
      {
        if (finsert >= 0)
          return HM_HOST;
        finsert = dp;
      }
      else
      {
        /*
         * If there were less than 4 hex digits, e.g. :ABC: shift right
         * so we don't interpret it as ABC0 -A1kmm
         */
        d[dp] = d[dp] >> 4 * nyble;
        nyble = 4;

        if (++dp >= 8)
          return HM_HOST;
      }
    }
    else if (c == '*')
    {
      /* * must be last, and * is ambiguous if there is a ::... -A1kmm */
      if (finsert >= 0 || *(p + 1) || dp == 0 || *(p - 1) != ':')
        return HM_HOST;
      bits = dp * 16;
    }
    else if (c == '/')
    {
      char *after;

      d[dp] = d[dp] >> 4 * nyble;
      ++dp;
      bits = strtoul(p + 1, &after, 10);

      if (bits < 0 || *after)
        return HM_HOST;
      if (bits > dp * 4 && !(finsert >= 0 && bits <= 128))
        return HM_HOST;
      break;
    }
    else
      return HM_HOST;
  }

  d[dp] = d[dp] >> 4 * nyble;

  if (c == 0)
    ++dp;
  if (finsert < 0 && bits == 0)
    bits = dp * 16;

  /* How many words are missing? -A1kmm */
  deficit = bits / 16 + ((bits % 16) ? 1 : 0) - dp;

  /* Now fill in the gaps(from ::) in the copied table... -A1kmm */
  for (dp = 0, nyble = 0; dp < 8; ++dp)
  {
    if (nyble == finsert && deficit)
    {
      dc[dp] = 0;
      deficit--;
    }
    else
      dc[dp] = d[nyble++];
  }

  /* Set unused bits to 0... -A1kmm */
  if (bits < 128 && (bits % 16 != 0))
    dc[bits / 16] &= ~((1 << (15 - bits % 16)) - 1);
  for (dp = bits / 16 + (bits % 16 ? 1 : 0); dp < 8; ++dp)
    dc[dp] = 0;

  /* And assign... -A1kmm */
  if (addr)
  {
    v6->sin6_family = AF_INET6;

    for (dp = 0; dp < 8; ++dp)
      /* The cast is a kludge to make netbsd work. */
      ((unsigned short *)&v6->sin6_addr)[dp] = htons(dc[dp]);
  }

  if (b)
    *b = bits;
  return HM_IPV6;
}

/* int try_parse_v4_netmask(const char *, struct irc_ssaddr *, int *);
 * Input: A possible IPV4 address as a string.
 * Output: An integer describing whether it is an IPV4 or hostmask,
 *         an address(if it is IPV4), a bitlength(if it is IPV4).
 * Side effects: None
 * Comments: Called from parse_netmask
 */
static int
try_parse_v4_netmask(const char *text, struct irc_ssaddr *addr, int *b)
{
  const char *digits[4];
  unsigned char addb[4];
  int n = 0, bits = 0;
  char c;
  struct sockaddr_in *const v4 = (struct sockaddr_in *)addr;

  digits[n++] = text;

  for (const char *p = text; (c = *p); ++p)
  {
    if (c >= '0' && c <= '9')   /* empty */
      ;
    else if (c == '.')
    {
      if (n >= 4)
        return HM_HOST;

      digits[n++] = p + 1;
    }
    else if (c == '*')
    {
      if (*(p + 1) || n == 1 || *(p - 1) != '.')
        return HM_HOST;

      bits = (n - 1) * 8;
      break;
    }
    else if (c == '/')
    {
      char *after;
      bits = strtoul(p + 1, &after, 10);

      if (bits < 0 || *after)
        return HM_HOST;
      if (bits > n * 8)
        return HM_HOST;

      break;
    }
    else
      return HM_HOST;
  }

  if (n < 4 && bits == 0)
    bits = n * 8;
  if (bits)
    while (n < 4)
      digits[n++] = "0";

  for (n = 0; n < 4; ++n)
    addb[n] = strtoul(digits[n], NULL, 10);

  if (bits == 0)
    bits = 32;

  /* Set unused bits to 0... -A1kmm */
  if (bits < 32 && bits % 8)
    addb[bits / 8] &= ~((1 << (8 - bits % 8)) - 1);
  for (n = bits / 8 + (bits % 8 ? 1 : 0); n < 4; ++n)
    addb[n] = 0;
  if (addr)
  {
    v4->sin_family = AF_INET;
    v4->sin_addr.s_addr =
      htonl(addb[0] << 24 | addb[1] << 16 | addb[2] << 8 | addb[3]);
  }

  if (b)
    *b = bits;
  return HM_IPV4;
}

/* int parse_netmask(const char *, struct irc_ssaddr *, int *);
 * Input: A hostmask, or an IPV4/6 address.
 * Output: An integer describing whether it is an IPV4, IPV6 address or a
 *         hostmask, an address(if it is an IP mask),
 *         a bitlength(if it is IP mask).
 * Side effects: None
 */
int
parse_netmask(const char *text, struct irc_ssaddr *addr, int *b)
{
  if (addr)
    memset(addr, 0, sizeof(struct irc_ssaddr));

  if (strchr(text, '.'))
    return try_parse_v4_netmask(text, addr, b);
  if (strchr(text, ':'))
    return try_parse_v6_netmask(text, addr, b);

  return HM_HOST;
}

/* The address matching stuff... */
/* int match_ipv6(struct irc_ssaddr *, struct irc_ssaddr *, int)
 * Input: An IP address, an IP mask, the number of bits in the mask.
 * Output: if match, -1 else 0
 * Side effects: None
 */
int
match_ipv6(const struct irc_ssaddr *addr, const struct irc_ssaddr *mask, int bits)
{
  int i, m, n = bits / 8;
  const struct sockaddr_in6 *const v6 = (const struct sockaddr_in6 *)addr;
  const struct sockaddr_in6 *const v6mask = (const struct sockaddr_in6 *)mask;

  for (i = 0; i < n; ++i)
    if (v6->sin6_addr.s6_addr[i] != v6mask->sin6_addr.s6_addr[i])
      return 0;

  if ((m = bits % 8) == 0)
    return -1;
  if ((v6->sin6_addr.s6_addr[n] & ~((1 << (8 - m)) - 1)) ==
      v6mask->sin6_addr.s6_addr[n])
    return -1;
  return 0;
}

/* int match_ipv4(struct irc_ssaddr *, struct irc_ssaddr *, int)
 * Input: An IP address, an IP mask, the number of bits in the mask.
 * Output: if match, -1 else 0
 * Side Effects: None
 */
int
match_ipv4(const struct irc_ssaddr *addr, const struct irc_ssaddr *mask, int bits)
{
  const struct sockaddr_in *const v4 = (const struct sockaddr_in *)addr;
  const struct sockaddr_in *const v4mask = (const struct sockaddr_in *)mask;

  if ((ntohl(v4->sin_addr.s_addr) & ~((1 << (32 - bits)) - 1)) !=
      ntohl(v4mask->sin_addr.s_addr))
    return 0;
  return -1;
}

/*
 * mask_addr
 *
 * inputs       - pointer to the ip to mask
 *              - bitlen
 * output       - NONE
 * side effects -
 */
void
mask_addr(struct irc_ssaddr *ip, int bits)
{
  int mask;
  struct sockaddr_in6 *v6_base_ip;
  int i, m, n;
  struct sockaddr_in *v4_base_ip;

  if (ip->ss.ss_family == AF_INET)
  {
    uint32_t tmp = 0;
    v4_base_ip = (struct sockaddr_in *)ip;

    mask = ~((1 << (32 - bits)) - 1);
    tmp = ntohl(v4_base_ip->sin_addr.s_addr);
    v4_base_ip->sin_addr.s_addr = htonl(tmp & mask);
  }
  else
  {
    n = bits / 8;
    m = bits % 8;
    v6_base_ip = (struct sockaddr_in6 *)ip;

    mask = ~((1 << (8 - m)) - 1);
    v6_base_ip->sin6_addr.s6_addr[n] = v6_base_ip->sin6_addr.s6_addr[n] & mask;

    for (i = n + 1; i < 16; i++)
      v6_base_ip->sin6_addr.s6_addr[i] = 0;
  }
}

/* unsigned long hash_ipv4(struct irc_ssaddr*)
 * Input: An IP address.
 * Output: A hash value of the IP address.
 * Side effects: None
 */
static uint32_t
hash_ipv4(const struct irc_ssaddr *addr, int bits)
{
  if (bits != 0)
  {
    const struct sockaddr_in *const v4 = (const struct sockaddr_in *)addr;
    uint32_t av = ntohl(v4->sin_addr.s_addr) & ~((1 << (32 - bits)) - 1);

    return (av ^ (av >> 12) ^ (av >> 24)) & (ATABLE_SIZE - 1);
  }

  return 0;
}

/* unsigned long hash_ipv6(struct irc_ssaddr*)
 * Input: An IP address.
 * Output: A hash value of the IP address.
 * Side effects: None
 */
static uint32_t
hash_ipv6(const struct irc_ssaddr *addr, int bits)
{
  uint32_t v = 0, n;
  const struct sockaddr_in6 *const v6 = (const struct sockaddr_in6 *)addr;

  for (n = 0; n < 16; ++n)
  {
    if (bits >= 8)
    {
      v ^= v6->sin6_addr.s6_addr[n];
      bits -= 8;
    }
    else if (bits)
    {
      v ^= v6->sin6_addr.s6_addr[n] & ~((1 << (8 - bits)) - 1);
      return v & (ATABLE_SIZE - 1);
    }
    else
      return v & (ATABLE_SIZE - 1);
  }

  return v & (ATABLE_SIZE - 1);
}

/* int hash_text(const char *start)
 * Input: The start of the text to hash.
 * Output: The hash of the string between 1 and (TH_MAX-1)
 * Side-effects: None.
 */
static uint32_t
hash_text(const char *start)
{
  uint32_t h = 0;

  for (const char *p = start; *p; ++p)
    h = (h << 4) - (h + ToLower(*p));

  return h & (ATABLE_SIZE - 1);
}

/* unsigned long get_hash_mask(const char *)
 * Input: The text to hash.
 * Output: The hash of the string right of the first '.' past the last
 *         wildcard in the string.
 * Side-effects: None.
 */
static uint32_t
get_mask_hash(const char *text)
{
  const char *hp = "", *p;

  for (p = text + strlen(text) - 1; p >= text; --p)
    if (IsMWildChar(*p))
      return hash_text(hp);
    else if (*p == '.')
      hp = p + 1;
  return hash_text(text);
}

/* struct MaskItem *find_conf_by_address(const char *, struct irc_ssaddr *,
 *                                         int type, int fam, const char *username)
 * Input: The hostname, the address, the type of mask to find, the address
 *        family, the username.
 * Output: The matching value with the highest precedence.
 * Side-effects: None
 * Note: Setting bit 0 of the type means that the username is ignored.
 * Warning: IsNeedPassword for everything that is not an auth{} entry
 * should always be true (i.e. conf->flags & CONF_FLAGS_NEED_PASSWORD == 0)
 */
struct MaskItem *
find_conf_by_address(const char *name, const struct irc_ssaddr *addr, unsigned int type,
                     int fam, const char *username, const char *password, int do_match)
{
  unsigned int hprecv = 0;
  dlink_node *node;
  struct MaskItem *hprec = NULL;
  struct AddressRec *arec = NULL;
  int (*cmpfunc)(const char *, const char *) = do_match ? match : irccmp;

  if (addr)
  {
    /* Check for IPV6 matches... */
    if (fam == AF_INET6)
    {
      for (int b = 128; b >= 0; b -= 16)
      {
        DLINK_FOREACH(node, atable[hash_ipv6(addr, b)].head)
        {
          arec = node->data;

          if ((arec->type == type) &&
              arec->precedence > hprecv &&
              arec->masktype == HM_IPV6 &&
              match_ipv6(addr, &arec->Mask.ipa.addr,
                         arec->Mask.ipa.bits) &&
              (!username || !cmpfunc(arec->username, username)) &&
              (IsNeedPassword(arec->conf) || arec->conf->passwd == NULL ||
               match_conf_password(password, arec->conf)))
          {
            hprecv = arec->precedence;
            hprec = arec->conf;
          }
        }
      }
    }
    else if (fam == AF_INET)
    {
      for (int b = 32; b >= 0; b -= 8)
      {
        DLINK_FOREACH(node, atable[hash_ipv4(addr, b)].head)
        {
          arec = node->data;

          if ((arec->type == type) &&
              arec->precedence > hprecv &&
              arec->masktype == HM_IPV4 &&
              match_ipv4(addr, &arec->Mask.ipa.addr,
                         arec->Mask.ipa.bits) &&
              (!username || !cmpfunc(arec->username, username)) &&
              (IsNeedPassword(arec->conf) || arec->conf->passwd == NULL ||
               match_conf_password(password, arec->conf)))
          {
            hprecv = arec->precedence;
            hprec = arec->conf;
          }
        }
      }
    }
  }

  if (name)
  {
    const char *p = name;

    while (1)
    {
        DLINK_FOREACH(node, atable[hash_text(p)].head)
        {
          arec = node->data;
          if ((arec->type == type) &&
            arec->precedence > hprecv &&
            (arec->masktype == HM_HOST) &&
            !cmpfunc(arec->Mask.hostname, name) &&
            (!username || !cmpfunc(arec->username, username)) &&
            (IsNeedPassword(arec->conf) || arec->conf->passwd == NULL ||
             match_conf_password(password, arec->conf)))
        {
          hprecv = arec->precedence;
          hprec = arec->conf;
        }
      }

      if ((p = strchr(p, '.')) == NULL)
        break;
      ++p;
    }

    DLINK_FOREACH(node, atable[0].head)
    {
      arec = node->data;

      if (arec->type == type &&
          arec->precedence > hprecv &&
          arec->masktype == HM_HOST &&
          !cmpfunc(arec->Mask.hostname, name) &&
          (!username || !cmpfunc(arec->username, username)) &&
          (IsNeedPassword(arec->conf) || arec->conf->passwd == NULL ||
           match_conf_password(password, arec->conf)))
      {
        hprecv = arec->precedence;
        hprec = arec->conf;
      }
    }
  }

  return hprec;
}

/* struct MaskItem* find_address_conf(const char*, const char*,
 *                                     struct irc_ssaddr*, int, char *);
 * Input: The hostname, username, address, address family.
 * Output: The applicable MaskItem.
 * Side-effects: None
 */
struct MaskItem *
find_address_conf(const char *host, const char *user, const struct irc_ssaddr *ip,
                  int aftype, const char *password)
{
  struct MaskItem *authcnf = NULL, *killcnf = NULL;

  /* Find the best auth{} block... If none, return NULL -A1kmm */
  if ((authcnf = find_conf_by_address(host, ip, CONF_CLIENT, aftype, user, password, 1)) == NULL)
    return NULL;

  /* If they are exempt from K-lines, return the best auth{} block. -A1kmm */
  if (IsConfExemptKline(authcnf))
    return authcnf;

  /* Find the best K-line... -A1kmm */
  killcnf = find_conf_by_address(host, ip, CONF_KLINE, aftype, user, NULL, 1);

  /*
   * If they are K-lined, return the K-line. Otherwise, return the
   * auth {} block. -A1kmm
   */
  if (killcnf)
    return killcnf;

  return authcnf;
}

/* struct MaskItem* find_dline_conf(struct irc_ssaddr*, int)
 *
 * Input:       An address, an address family.
 * Output:      The best matching D-line or exempt line.
 * Side effects: None.
 */
struct MaskItem *
find_dline_conf(const struct irc_ssaddr *addr, int aftype)
{
  struct MaskItem *eline;

  eline = find_conf_by_address(NULL, addr, CONF_EXEMPT, aftype, NULL, NULL, 1);
  if (eline)
    return eline;

  return find_conf_by_address(NULL, addr, CONF_DLINE, aftype, NULL, NULL, 1);
}

/* void add_conf_by_address(int, struct MaskItem *aconf)
 * Input:
 * Output: None
 * Side-effects: Adds this entry to the hash table.
 */
struct AddressRec *
add_conf_by_address(const unsigned int type, struct MaskItem *conf)
{
  const char *const hostname = conf->host;
  const char *const username = conf->user;
  static unsigned int prec_value = UINT_MAX;
  int bits = 0;

  assert(type && !EmptyString(hostname));

  struct AddressRec *arec = xcalloc(sizeof(struct AddressRec));
  arec->masktype = parse_netmask(hostname, &arec->Mask.ipa.addr, &bits);
  arec->Mask.ipa.bits = bits;
  arec->username = username;
  arec->conf = conf;
  arec->precedence = prec_value--;
  arec->type = type;

  switch (arec->masktype)
  {
    case HM_IPV4:
      /* We have to do this, since we do not re-hash for every bit -A1kmm. */
      bits -= bits % 8;
      dlinkAdd(arec, &arec->node, &atable[hash_ipv4(&arec->Mask.ipa.addr, bits)]);
      break;
    case HM_IPV6:
      /* We have to do this, since we do not re-hash for every bit -A1kmm. */
      bits -= bits % 16;
      dlinkAdd(arec, &arec->node, &atable[hash_ipv6(&arec->Mask.ipa.addr, bits)]);
      break;
    default: /* HM_HOST */
      arec->Mask.hostname = hostname;
      dlinkAdd(arec, &arec->node, &atable[get_mask_hash(hostname)]);
      break;
  }

  return arec;
}

/* void delete_one_address(const char*, struct MaskItem*)
 * Input: An address string, the associated MaskItem.
 * Output: None
 * Side effects: Deletes an address record. Frees the MaskItem if there
 *               is nothing referencing it, sets it as illegal otherwise.
 */
void
delete_one_address_conf(const char *address, struct MaskItem *conf)
{
  int bits = 0;
  uint32_t hv = 0;
  dlink_node *node;
  struct irc_ssaddr addr;

  switch (parse_netmask(address, &addr, &bits))
  {
    case HM_IPV4:
      /* We have to do this, since we do not re-hash for every bit -A1kmm. */
      bits -= bits % 8;
      hv = hash_ipv4(&addr, bits);
      break;
    case HM_IPV6:
      /* We have to do this, since we do not re-hash for every bit -A1kmm. */
      bits -= bits % 16;
      hv = hash_ipv6(&addr, bits);
      break;
    default: /* HM_HOST */
      hv = get_mask_hash(address);
      break;
  }

  DLINK_FOREACH(node, atable[hv].head)
  {
    struct AddressRec *arec = node->data;

    if (arec->conf == conf)
    {
      dlinkDelete(&arec->node, &atable[hv]);

      if (!conf->ref_count)
        conf_free(conf);

      xfree(arec);
      return;
    }
  }
}

/* void clear_out_address_conf(void)
 * Input: None
 * Output: None
 * Side effects: Clears out all address records in the hash table,
 *               frees them, and frees the MaskItems if nothing references
 *               them, otherwise sets them as illegal.
 */
void
clear_out_address_conf(void)
{
  dlink_node *node, *node_next;

  for (unsigned int i = 0; i < ATABLE_SIZE; ++i)
  {
    DLINK_FOREACH_SAFE(node, node_next, atable[i].head)
    {
      struct AddressRec *arec = node->data;

      /*
       * Destroy the ircd.conf items and keep those that are in the databases
       */
      if (IsConfDatabase(arec->conf))
        continue;

      dlinkDelete(&arec->node, &atable[i]);
      arec->conf->active = 0;

      if (!arec->conf->ref_count)
        conf_free(arec->conf);
      xfree(arec);
    }
  }
}

static void
hostmask_send_expiration(const struct AddressRec *const arec)
{
  char ban_type = '?';

  if (!ConfigGeneral.tkline_expire_notices)
    return;

  switch (arec->type)
  {
    case CONF_KLINE:
      ban_type = 'K';
      break;
    case CONF_DLINE:
      ban_type = 'D';
      break;
    default: break;
  }

  sendto_realops_flags(UMODE_SERVNOTICE, L_ALL, SEND_NOTICE,
                       "Temporary %c-line for [%s@%s] expired", ban_type,
                       (arec->conf->user) ? arec->conf->user : "*",
                       (arec->conf->host) ? arec->conf->host : "*");
}

void
hostmask_expire_temporary(void)
{
  dlink_node *node, *node_next;

  for (unsigned int i = 0; i < ATABLE_SIZE; ++i)
  {
    DLINK_FOREACH_SAFE(node, node_next, atable[i].head)
    {
      struct AddressRec *arec = node->data;

      if (!arec->conf->until || arec->conf->until > CurrentTime)
        continue;

      switch (arec->type)
      {
        case CONF_KLINE:
        case CONF_DLINE:
          hostmask_send_expiration(arec);

          dlinkDelete(&arec->node, &atable[i]);
          conf_free(arec->conf);
          xfree(arec);
          break;
        default: break;
      }
    }
  }
}
Revision:	7924
Committed:	Sat Dec 31 13:57:08 2016 UTC (8 years, 7 months ago) by michael
Content type:	text/x-csrc
File size:	20581 byte(s)
Log Message:	- Update copyright years
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 2001-2017 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 hostmask.c
23	* \brief Code to efficiently find IP & hostmask based configs.
24	* \version $Id$
25	*/
26
27	#include "stdinc.h"
28	#include "memory.h"
29	#include "ircd_defs.h"
30	#include "list.h"
31	#include "conf.h"
32	#include "hostmask.h"
33	#include "send.h"
34	#include "irc_string.h"
35	#include "ircd.h"
36
37
38	#define DigitParse(ch) do { \
39	if (ch >= '0' && ch <= '9') \
40	ch = ch - '0'; \
41	else if (ch >= 'A' && ch <= 'F') \
42	ch = ch - 'A' + 10; \
43	else if (ch >= 'a' && ch <= 'f') \
44	ch = ch - 'a' + 10; \
45	} while (0);
46
47	/* Hashtable stuff...now external as it's used in m_stats.c */
48	dlink_list atable[ATABLE_SIZE];
49
50	/* The mask parser/type determination code... */
51
52	/* int try_parse_v6_netmask(const char , struct irc_ssaddr , int *);
53	* Input: A possible IPV6 address as a string.
54	* Output: An integer describing whether it is an IPV6 or hostmask,
55	* an address(if it is IPV6), a bitlength(if it is IPV6).
56	* Side effects: None
57	* Comments: Called from parse_netmask
58	*/
59	static int
60	try_parse_v6_netmask(const char text, struct irc_ssaddr addr, int *b)
61	{
62	char c;
63	int d[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
64	int dp = 0;
65	int nyble = 4;
66	int finsert = -1;
67	int bits = 128;
68	int deficit = 0;
69	short dc[8];
70	struct sockaddr_in6 const v6 = (struct sockaddr_in6 )addr;
71
72	for (const char p = text; (c = p); ++p)
73	{
74	if (IsXDigit(c))
75	{
76	if (nyble == 0)
77	return HM_HOST;
78	DigitParse(c);
79	d[dp] \|= c << (4 * --nyble);
80	}
81	else if (c == ':')
82	{
83	if (p > text && *(p - 1) == ':')
84	{
85	if (finsert >= 0)
86	return HM_HOST;
87	finsert = dp;
88	}
89	else
90	{
91	/*
92	* If there were less than 4 hex digits, e.g. :ABC: shift right
93	* so we don't interpret it as ABC0 -A1kmm
94	*/
95	d[dp] = d[dp] >> 4 * nyble;
96	nyble = 4;
97
98	if (++dp >= 8)
99	return HM_HOST;
100	}
101	}
102	else if (c == '*')
103	{
104	/* * must be last, and * is ambiguous if there is a ::... -A1kmm */
105	if (finsert >= 0 \|\| (p + 1) \|\| dp == 0 \|\| (p - 1) != ':')
106	return HM_HOST;
107	bits = dp * 16;
108	}
109	else if (c == '/')
110	{
111	char *after;
112
113	d[dp] = d[dp] >> 4 * nyble;
114	++dp;
115	bits = strtoul(p + 1, &after, 10);
116
117	if (bits < 0 \|\| *after)
118	return HM_HOST;
119	if (bits > dp * 4 && !(finsert >= 0 && bits <= 128))
120	return HM_HOST;
121	break;
122	}
123	else
124	return HM_HOST;
125	}
126
127	d[dp] = d[dp] >> 4 * nyble;
128
129	if (c == 0)
130	++dp;
131	if (finsert < 0 && bits == 0)
132	bits = dp * 16;
133
134	/* How many words are missing? -A1kmm */
135	deficit = bits / 16 + ((bits % 16) ? 1 : 0) - dp;
136
137	/* Now fill in the gaps(from ::) in the copied table... -A1kmm */
138	for (dp = 0, nyble = 0; dp < 8; ++dp)
139	{
140	if (nyble == finsert && deficit)
141	{
142	dc[dp] = 0;
143	deficit--;
144	}
145	else
146	dc[dp] = d[nyble++];
147	}
148
149	/* Set unused bits to 0... -A1kmm */
150	if (bits < 128 && (bits % 16 != 0))
151	dc[bits / 16] &= ~((1 << (15 - bits % 16)) - 1);
152	for (dp = bits / 16 + (bits % 16 ? 1 : 0); dp < 8; ++dp)
153	dc[dp] = 0;
154
155	/* And assign... -A1kmm */
156	if (addr)
157	{
158	v6->sin6_family = AF_INET6;
159
160	for (dp = 0; dp < 8; ++dp)
161	/* The cast is a kludge to make netbsd work. */
162	((unsigned short *)&v6->sin6_addr)[dp] = htons(dc[dp]);
163	}
164
165	if (b)
166	*b = bits;
167	return HM_IPV6;
168	}
169
170	/* int try_parse_v4_netmask(const char , struct irc_ssaddr , int *);
171	* Input: A possible IPV4 address as a string.
172	* Output: An integer describing whether it is an IPV4 or hostmask,
173	* an address(if it is IPV4), a bitlength(if it is IPV4).
174	* Side effects: None
175	* Comments: Called from parse_netmask
176	*/
177	static int
178	try_parse_v4_netmask(const char text, struct irc_ssaddr addr, int *b)
179	{
180	const char *digits[4];
181	unsigned char addb[4];
182	int n = 0, bits = 0;
183	char c;
184	struct sockaddr_in const v4 = (struct sockaddr_in )addr;
185
186	digits[n++] = text;
187
188	for (const char p = text; (c = p); ++p)
189	{
190	if (c >= '0' && c <= '9') /* empty */
191	;
192	else if (c == '.')
193	{
194	if (n >= 4)
195	return HM_HOST;
196
197	digits[n++] = p + 1;
198	}
199	else if (c == '*')
200	{
201	if ((p + 1) \|\| n == 1 \|\| (p - 1) != '.')
202	return HM_HOST;
203
204	bits = (n - 1) * 8;
205	break;
206	}
207	else if (c == '/')
208	{
209	char *after;
210	bits = strtoul(p + 1, &after, 10);
211
212	if (bits < 0 \|\| *after)
213	return HM_HOST;
214	if (bits > n * 8)
215	return HM_HOST;
216
217	break;
218	}
219	else
220	return HM_HOST;
221	}
222
223	if (n < 4 && bits == 0)
224	bits = n * 8;
225	if (bits)
226	while (n < 4)
227	digits[n++] = "0";
228
229	for (n = 0; n < 4; ++n)
230	addb[n] = strtoul(digits[n], NULL, 10);
231
232	if (bits == 0)
233	bits = 32;
234
235	/* Set unused bits to 0... -A1kmm */
236	if (bits < 32 && bits % 8)
237	addb[bits / 8] &= ~((1 << (8 - bits % 8)) - 1);
238	for (n = bits / 8 + (bits % 8 ? 1 : 0); n < 4; ++n)
239	addb[n] = 0;
240	if (addr)
241	{
242	v4->sin_family = AF_INET;
243	v4->sin_addr.s_addr =
244	htonl(addb[0] << 24 \| addb[1] << 16 \| addb[2] << 8 \| addb[3]);
245	}
246
247	if (b)
248	*b = bits;
249	return HM_IPV4;
250	}
251
252	/* int parse_netmask(const char , struct irc_ssaddr , int *);
253	* Input: A hostmask, or an IPV4/6 address.
254	* Output: An integer describing whether it is an IPV4, IPV6 address or a
255	* hostmask, an address(if it is an IP mask),
256	* a bitlength(if it is IP mask).
257	* Side effects: None
258	*/
259	int
260	parse_netmask(const char text, struct irc_ssaddr addr, int *b)
261	{
262	if (addr)
263	memset(addr, 0, sizeof(struct irc_ssaddr));
264
265	if (strchr(text, '.'))
266	return try_parse_v4_netmask(text, addr, b);
267	if (strchr(text, ':'))
268	return try_parse_v6_netmask(text, addr, b);
269
270	return HM_HOST;
271	}
272
273	/* The address matching stuff... */
274	/* int match_ipv6(struct irc_ssaddr , struct irc_ssaddr , int)
275	* Input: An IP address, an IP mask, the number of bits in the mask.
276	* Output: if match, -1 else 0
277	* Side effects: None
278	*/
279	int
280	match_ipv6(const struct irc_ssaddr addr, const struct irc_ssaddr mask, int bits)
281	{
282	int i, m, n = bits / 8;
283	const struct sockaddr_in6 const v6 = (const struct sockaddr_in6 )addr;
284	const struct sockaddr_in6 const v6mask = (const struct sockaddr_in6 )mask;
285
286	for (i = 0; i < n; ++i)
287	if (v6->sin6_addr.s6_addr[i] != v6mask->sin6_addr.s6_addr[i])
288	return 0;
289
290	if ((m = bits % 8) == 0)
291	return -1;
292	if ((v6->sin6_addr.s6_addr[n] & ~((1 << (8 - m)) - 1)) ==
293	v6mask->sin6_addr.s6_addr[n])
294	return -1;
295	return 0;
296	}
297
298	/* int match_ipv4(struct irc_ssaddr , struct irc_ssaddr , int)
299	* Input: An IP address, an IP mask, the number of bits in the mask.
300	* Output: if match, -1 else 0
301	* Side Effects: None
302	*/
303	int
304	match_ipv4(const struct irc_ssaddr addr, const struct irc_ssaddr mask, int bits)
305	{
306	const struct sockaddr_in const v4 = (const struct sockaddr_in )addr;
307	const struct sockaddr_in const v4mask = (const struct sockaddr_in )mask;
308
309	if ((ntohl(v4->sin_addr.s_addr) & ~((1 << (32 - bits)) - 1)) !=
310	ntohl(v4mask->sin_addr.s_addr))
311	return 0;
312	return -1;
313	}
314
315	/*
316	* mask_addr
317	*
318	* inputs - pointer to the ip to mask
319	* - bitlen
320	* output - NONE
321	* side effects -
322	*/
323	void
324	mask_addr(struct irc_ssaddr *ip, int bits)
325	{
326	int mask;
327	struct sockaddr_in6 *v6_base_ip;
328	int i, m, n;
329	struct sockaddr_in *v4_base_ip;
330
331	if (ip->ss.ss_family == AF_INET)
332	{
333	uint32_t tmp = 0;
334	v4_base_ip = (struct sockaddr_in *)ip;
335
336	mask = ~((1 << (32 - bits)) - 1);
337	tmp = ntohl(v4_base_ip->sin_addr.s_addr);
338	v4_base_ip->sin_addr.s_addr = htonl(tmp & mask);
339	}
340	else
341	{
342	n = bits / 8;
343	m = bits % 8;
344	v6_base_ip = (struct sockaddr_in6 *)ip;
345
346	mask = ~((1 << (8 - m)) - 1);
347	v6_base_ip->sin6_addr.s6_addr[n] = v6_base_ip->sin6_addr.s6_addr[n] & mask;
348
349	for (i = n + 1; i < 16; i++)
350	v6_base_ip->sin6_addr.s6_addr[i] = 0;
351	}
352	}
353
354	/* unsigned long hash_ipv4(struct irc_ssaddr*)
355	* Input: An IP address.
356	* Output: A hash value of the IP address.
357	* Side effects: None
358	*/
359	static uint32_t
360	hash_ipv4(const struct irc_ssaddr *addr, int bits)
361	{
362	if (bits != 0)
363	{
364	const struct sockaddr_in const v4 = (const struct sockaddr_in )addr;
365	uint32_t av = ntohl(v4->sin_addr.s_addr) & ~((1 << (32 - bits)) - 1);
366
367	return (av ^ (av >> 12) ^ (av >> 24)) & (ATABLE_SIZE - 1);
368	}
369
370	return 0;
371	}
372
373	/* unsigned long hash_ipv6(struct irc_ssaddr*)
374	* Input: An IP address.
375	* Output: A hash value of the IP address.
376	* Side effects: None
377	*/
378	static uint32_t
379	hash_ipv6(const struct irc_ssaddr *addr, int bits)
380	{
381	uint32_t v = 0, n;
382	const struct sockaddr_in6 const v6 = (const struct sockaddr_in6 )addr;
383
384	for (n = 0; n < 16; ++n)
385	{
386	if (bits >= 8)
387	{
388	v ^= v6->sin6_addr.s6_addr[n];
389	bits -= 8;
390	}
391	else if (bits)
392	{
393	v ^= v6->sin6_addr.s6_addr[n] & ~((1 << (8 - bits)) - 1);
394	return v & (ATABLE_SIZE - 1);
395	}
396	else
397	return v & (ATABLE_SIZE - 1);
398	}
399
400	return v & (ATABLE_SIZE - 1);
401	}
402
403	/* int hash_text(const char *start)
404	* Input: The start of the text to hash.
405	* Output: The hash of the string between 1 and (TH_MAX-1)
406	* Side-effects: None.
407	*/
408	static uint32_t
409	hash_text(const char *start)
410	{
411	uint32_t h = 0;
412
413	for (const char p = start; p; ++p)
414	h = (h << 4) - (h + ToLower(*p));
415
416	return h & (ATABLE_SIZE - 1);
417	}
418
419	/* unsigned long get_hash_mask(const char *)
420	* Input: The text to hash.
421	* Output: The hash of the string right of the first '.' past the last
422	* wildcard in the string.
423	* Side-effects: None.
424	*/
425	static uint32_t
426	get_mask_hash(const char *text)
427	{
428	const char hp = "", p;
429
430	for (p = text + strlen(text) - 1; p >= text; --p)
431	if (IsMWildChar(*p))
432	return hash_text(hp);
433	else if (*p == '.')
434	hp = p + 1;
435	return hash_text(text);
436	}
437
438	/* struct MaskItem find_conf_by_address(const char , struct irc_ssaddr *,
439	* int type, int fam, const char *username)
440	* Input: The hostname, the address, the type of mask to find, the address
441	* family, the username.
442	* Output: The matching value with the highest precedence.
443	* Side-effects: None
444	* Note: Setting bit 0 of the type means that the username is ignored.
445	* Warning: IsNeedPassword for everything that is not an auth{} entry
446	* should always be true (i.e. conf->flags & CONF_FLAGS_NEED_PASSWORD == 0)
447	*/
448	struct MaskItem *
449	find_conf_by_address(const char name, const struct irc_ssaddr addr, unsigned int type,
450	int fam, const char username, const char password, int do_match)
451	{
452	unsigned int hprecv = 0;
453	dlink_node *node;
454	struct MaskItem *hprec = NULL;
455	struct AddressRec *arec = NULL;
456	int (cmpfunc)(const char , const char *) = do_match ? match : irccmp;
457
458	if (addr)
459	{
460	/* Check for IPV6 matches... */
461	if (fam == AF_INET6)
462	{
463	for (int b = 128; b >= 0; b -= 16)
464	{
465	DLINK_FOREACH(node, atable[hash_ipv6(addr, b)].head)
466	{
467	arec = node->data;
468
469	if ((arec->type == type) &&
470	arec->precedence > hprecv &&
471	arec->masktype == HM_IPV6 &&
472	match_ipv6(addr, &arec->Mask.ipa.addr,
473	arec->Mask.ipa.bits) &&
474	(!username \|\| !cmpfunc(arec->username, username)) &&
475	(IsNeedPassword(arec->conf) \|\| arec->conf->passwd == NULL \|\|
476	match_conf_password(password, arec->conf)))
477	{
478	hprecv = arec->precedence;
479	hprec = arec->conf;
480	}
481	}
482	}
483	}
484	else if (fam == AF_INET)
485	{
486	for (int b = 32; b >= 0; b -= 8)
487	{
488	DLINK_FOREACH(node, atable[hash_ipv4(addr, b)].head)
489	{
490	arec = node->data;
491
492	if ((arec->type == type) &&
493	arec->precedence > hprecv &&
494	arec->masktype == HM_IPV4 &&
495	match_ipv4(addr, &arec->Mask.ipa.addr,
496	arec->Mask.ipa.bits) &&
497	(!username \|\| !cmpfunc(arec->username, username)) &&
498	(IsNeedPassword(arec->conf) \|\| arec->conf->passwd == NULL \|\|
499	match_conf_password(password, arec->conf)))
500	{
501	hprecv = arec->precedence;
502	hprec = arec->conf;
503	}
504	}
505	}
506	}
507	}
508
509	if (name)
510	{
511	const char *p = name;
512
513	while (1)
514	{
515	DLINK_FOREACH(node, atable[hash_text(p)].head)
516	{
517	arec = node->data;
518	if ((arec->type == type) &&
519	arec->precedence > hprecv &&
520	(arec->masktype == HM_HOST) &&
521	!cmpfunc(arec->Mask.hostname, name) &&
522	(!username \|\| !cmpfunc(arec->username, username)) &&
523	(IsNeedPassword(arec->conf) \|\| arec->conf->passwd == NULL \|\|
524	match_conf_password(password, arec->conf)))
525	{
526	hprecv = arec->precedence;
527	hprec = arec->conf;
528	}
529	}
530
531	if ((p = strchr(p, '.')) == NULL)
532	break;
533	++p;
534	}
535
536	DLINK_FOREACH(node, atable[0].head)
537	{
538	arec = node->data;
539
540	if (arec->type == type &&
541	arec->precedence > hprecv &&
542	arec->masktype == HM_HOST &&
543	!cmpfunc(arec->Mask.hostname, name) &&
544	(!username \|\| !cmpfunc(arec->username, username)) &&
545	(IsNeedPassword(arec->conf) \|\| arec->conf->passwd == NULL \|\|
546	match_conf_password(password, arec->conf)))
547	{
548	hprecv = arec->precedence;
549	hprec = arec->conf;
550	}
551	}
552	}
553
554	return hprec;
555	}
556
557	/* struct MaskItem* find_address_conf(const char, const char,
558	* struct irc_ssaddr, int, char );
559	* Input: The hostname, username, address, address family.
560	* Output: The applicable MaskItem.
561	* Side-effects: None
562	*/
563	struct MaskItem *
564	find_address_conf(const char host, const char user, const struct irc_ssaddr *ip,
565	int aftype, const char *password)
566	{
567	struct MaskItem authcnf = NULL, killcnf = NULL;
568
569	/* Find the best auth{} block... If none, return NULL -A1kmm */
570	if ((authcnf = find_conf_by_address(host, ip, CONF_CLIENT, aftype, user, password, 1)) == NULL)
571	return NULL;
572
573	/* If they are exempt from K-lines, return the best auth{} block. -A1kmm */
574	if (IsConfExemptKline(authcnf))
575	return authcnf;
576
577	/* Find the best K-line... -A1kmm */
578	killcnf = find_conf_by_address(host, ip, CONF_KLINE, aftype, user, NULL, 1);
579
580	/*
581	* If they are K-lined, return the K-line. Otherwise, return the
582	* auth {} block. -A1kmm
583	*/
584	if (killcnf)
585	return killcnf;
586
587	return authcnf;
588	}
589
590	/* struct MaskItem* find_dline_conf(struct irc_ssaddr*, int)
591	*
592	* Input: An address, an address family.
593	* Output: The best matching D-line or exempt line.
594	* Side effects: None.
595	*/
596	struct MaskItem *
597	find_dline_conf(const struct irc_ssaddr *addr, int aftype)
598	{
599	struct MaskItem *eline;
600
601	eline = find_conf_by_address(NULL, addr, CONF_EXEMPT, aftype, NULL, NULL, 1);
602	if (eline)
603	return eline;
604
605	return find_conf_by_address(NULL, addr, CONF_DLINE, aftype, NULL, NULL, 1);
606	}
607
608	/* void add_conf_by_address(int, struct MaskItem *aconf)
609	* Input:
610	* Output: None
611	* Side-effects: Adds this entry to the hash table.
612	*/
613	struct AddressRec *
614	add_conf_by_address(const unsigned int type, struct MaskItem *conf)
615	{
616	const char *const hostname = conf->host;
617	const char *const username = conf->user;
618	static unsigned int prec_value = UINT_MAX;
619	int bits = 0;
620
621	assert(type && !EmptyString(hostname));
622
623	struct AddressRec *arec = xcalloc(sizeof(struct AddressRec));
624	arec->masktype = parse_netmask(hostname, &arec->Mask.ipa.addr, &bits);
625	arec->Mask.ipa.bits = bits;
626	arec->username = username;
627	arec->conf = conf;
628	arec->precedence = prec_value--;
629	arec->type = type;
630
631	switch (arec->masktype)
632	{
633	case HM_IPV4:
634	/* We have to do this, since we do not re-hash for every bit -A1kmm. */
635	bits -= bits % 8;
636	dlinkAdd(arec, &arec->node, &atable[hash_ipv4(&arec->Mask.ipa.addr, bits)]);
637	break;
638	case HM_IPV6:
639	/* We have to do this, since we do not re-hash for every bit -A1kmm. */
640	bits -= bits % 16;
641	dlinkAdd(arec, &arec->node, &atable[hash_ipv6(&arec->Mask.ipa.addr, bits)]);
642	break;
643	default: /* HM_HOST */
644	arec->Mask.hostname = hostname;
645	dlinkAdd(arec, &arec->node, &atable[get_mask_hash(hostname)]);
646	break;
647	}
648
649	return arec;
650	}
651
652	/* void delete_one_address(const char, struct MaskItem)
653	* Input: An address string, the associated MaskItem.
654	* Output: None
655	* Side effects: Deletes an address record. Frees the MaskItem if there
656	* is nothing referencing it, sets it as illegal otherwise.
657	*/
658	void
659	delete_one_address_conf(const char address, struct MaskItem conf)
660	{
661	int bits = 0;
662	uint32_t hv = 0;
663	dlink_node *node;
664	struct irc_ssaddr addr;
665
666	switch (parse_netmask(address, &addr, &bits))
667	{
668	case HM_IPV4:
669	/* We have to do this, since we do not re-hash for every bit -A1kmm. */
670	bits -= bits % 8;
671	hv = hash_ipv4(&addr, bits);
672	break;
673	case HM_IPV6:
674	/* We have to do this, since we do not re-hash for every bit -A1kmm. */
675	bits -= bits % 16;
676	hv = hash_ipv6(&addr, bits);
677	break;
678	default: /* HM_HOST */
679	hv = get_mask_hash(address);
680	break;
681	}
682
683	DLINK_FOREACH(node, atable[hv].head)
684	{
685	struct AddressRec *arec = node->data;
686
687	if (arec->conf == conf)
688	{
689	dlinkDelete(&arec->node, &atable[hv]);
690
691	if (!conf->ref_count)
692	conf_free(conf);
693
694	xfree(arec);
695	return;
696	}
697	}
698	}
699
700	/* void clear_out_address_conf(void)
701	* Input: None
702	* Output: None
703	* Side effects: Clears out all address records in the hash table,
704	* frees them, and frees the MaskItems if nothing references
705	* them, otherwise sets them as illegal.
706	*/
707	void
708	clear_out_address_conf(void)
709	{
710	dlink_node node, node_next;
711
712	for (unsigned int i = 0; i < ATABLE_SIZE; ++i)
713	{
714	DLINK_FOREACH_SAFE(node, node_next, atable[i].head)
715	{
716	struct AddressRec *arec = node->data;
717
718	/*
719	* Destroy the ircd.conf items and keep those that are in the databases
720	*/
721	if (IsConfDatabase(arec->conf))
722	continue;
723
724	dlinkDelete(&arec->node, &atable[i]);
725	arec->conf->active = 0;
726
727	if (!arec->conf->ref_count)
728	conf_free(arec->conf);
729	xfree(arec);
730	}
731	}
732	}
733
734	static void
735	hostmask_send_expiration(const struct AddressRec *const arec)
736	{
737	char ban_type = '?';
738
739	if (!ConfigGeneral.tkline_expire_notices)
740	return;
741
742	switch (arec->type)
743	{
744	case CONF_KLINE:
745	ban_type = 'K';
746	break;
747	case CONF_DLINE:
748	ban_type = 'D';
749	break;
750	default: break;
751	}
752
753	sendto_realops_flags(UMODE_SERVNOTICE, L_ALL, SEND_NOTICE,
754	"Temporary %c-line for [%s@%s] expired", ban_type,
755	(arec->conf->user) ? arec->conf->user : "*",
756	(arec->conf->host) ? arec->conf->host : "*");
757	}
758
759	void
760	hostmask_expire_temporary(void)
761	{
762	dlink_node node, node_next;
763
764	for (unsigned int i = 0; i < ATABLE_SIZE; ++i)
765	{
766	DLINK_FOREACH_SAFE(node, node_next, atable[i].head)
767	{
768	struct AddressRec *arec = node->data;
769
770	if (!arec->conf->until \|\| arec->conf->until > CurrentTime)
771	continue;
772
773	switch (arec->type)
774	{
775	case CONF_KLINE:
776	case CONF_DLINE:
777	hostmask_send_expiration(arec);
778
779	dlinkDelete(&arec->node, &atable[i]);
780	conf_free(arec->conf);
781	xfree(arec);
782	break;
783	default: break;
784	}
785	}
786	}
787	}