permissions/hash.c

Go to the documentation of this file.

/*
 * Hash functions for cached trusted and address tables
 *
 * Copyright (C) 2003-2006 Juha Heinanen
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <sys/types.h>
#include <regex.h>
#include "../../mem/shm_mem.h"
#include "../../parser/parse_from.h"
#include "../../ut.h"
#include "../../hash_func.h"
#include "../../usr_avp.h"
#include "../../ip_addr.h"
#include "../../pvar.h"
#include "hash.h"
#include "trusted.h"
#include "address.h"

#define perm_hash(_s)  core_hash( &(_s), 0, PERM_HASH_SIZE)


/* tag AVP specs */
static int     tag_avp_type;
static int_str tag_avp;


/*
 * Parse and set tag AVP specs
 */
int init_tag_avp(str *tag_avp_param)
{
    pv_spec_t avp_spec;
    unsigned short avp_flags;

    if (tag_avp_param->s && tag_avp_param->len > 0) {
   if (pv_parse_spec(tag_avp_param, &avp_spec)==0
       || avp_spec.type != PVT_AVP) {
       LM_ERR("malformed or non "
      "AVP %.*s peer_tag_avp definition\n", tag_avp_param->len, tag_avp_param->s);
       return -1;
   }
   if(pv_get_avp_name(0, &avp_spec.pvp, &tag_avp, &avp_flags)!=0) {
       LM_ERR("[%.*s]- invalid "
      "peer_tag_avp AVP definition\n", tag_avp_param->len, tag_avp_param->s);
       return -1;
   }
   tag_avp_type = avp_flags;
    } else {
   tag_avp.n = 0;
    }
    return 0;
}


/*
 * Gets tag avp specs
 */
void get_tag_avp(int_str *tag_avp_p, int *tag_avp_type_p)
{
   *tag_avp_p = tag_avp;
   *tag_avp_type_p = tag_avp_type;
}


/*
 * Create and initialize a hash table
 */
struct trusted_list** new_hash_table(void)
{
   struct trusted_list** ptr;

   /* Initializing hash tables and hash table variable */
   ptr = (struct trusted_list **)shm_malloc
      (sizeof(struct trusted_list*) * PERM_HASH_SIZE);
   if (!ptr) {
      LM_ERR("no shm memory for hash table\n");
      return 0;
   }

   memset(ptr, 0, sizeof(struct trusted_list*) * PERM_HASH_SIZE);
   return ptr;
}


/*
 * Release all memory allocated for a hash table
 */
void free_hash_table(struct trusted_list** table)
{
   if (!table)
      return;

   empty_hash_table(table);
   shm_free(table);
}


/* 
 * Add <src_ip, proto, pattern, tag> into hash table, where proto is integer
 * representation of string argument proto.
 */
int hash_table_insert(struct trusted_list** table, char* src_ip, 
            char* proto, char* pattern, char* tag)
{
   struct trusted_list *np;
   unsigned int hash_val;

   np = (struct trusted_list *) shm_malloc(sizeof(*np));
   if (np == NULL) {
      LM_ERR("cannot allocate shm memory for table entry\n");
      return -1;
   }

   if (strcasecmp(proto, "any") == 0) {
      np->proto = PROTO_NONE;
   } else if (strcasecmp(proto, "udp") == 0) {
      np->proto = PROTO_UDP;
   } else if (strcasecmp(proto, "tcp") == 0) {
      np->proto = PROTO_TCP;
   } else if (strcasecmp(proto, "tls") == 0) {
      np->proto = PROTO_TLS;
   } else if (strcasecmp(proto, "sctp") == 0) {
      np->proto = PROTO_SCTP;
   } else if (strcasecmp(proto, "none") == 0) {
           shm_free(np);
      return 1;
   } else {
      LM_CRIT("unknown protocol\n");
      shm_free(np);
      return -1;
   }

   np->src_ip.len = strlen(src_ip);
   np->src_ip.s = (char *) shm_malloc(np->src_ip.len);

   if (np->src_ip.s == NULL) {
      LM_CRIT("cannot allocate shm memory for src_ip string\n");
      shm_free(np);
      return -1;
   }

   (void) strncpy(np->src_ip.s, src_ip, np->src_ip.len);

   if (pattern) {
       np->pattern = (char *) shm_malloc(strlen(pattern)+1);
       if (np->pattern == NULL) {
      LM_CRIT("cannot allocate shm memory for pattern string\n");
      shm_free(np->src_ip.s);
      shm_free(np);
      return -1;
       }
       (void) strcpy(np->pattern, pattern);
   } else {
       np->pattern = 0;
   }

   if (tag) {
       np->tag.len = strlen(tag);
       np->tag.s = (char *) shm_malloc((np->tag.len) + 1);
       if (np->tag.s == NULL) {
      LM_CRIT("cannot allocate shm memory for pattern string\n");
      shm_free(np->src_ip.s);
      shm_free(np->pattern);
      shm_free(np);
      return -1;
       }
       (void) strcpy(np->tag.s, tag);
   } else {
       np->tag.len = 0;
       np->tag.s = 0;
   }

   hash_val = perm_hash(np->src_ip);
   np->next = table[hash_val];
   table[hash_val] = np;

   return 1;
}


/* 
 * Check if an entry exists in hash table that has given src_ip and protocol
 * value and pattern that matches to From URI.  If an entry exists and tag_avp
 * has been defined, tag of the entry is added as a value to tag_avp.
 */
int match_hash_table(struct trusted_list** table, struct sip_msg* msg,
           char *src_ip_c_str, int proto)
{
   str uri;
   char uri_string[MAX_URI_SIZE + 1];
   regex_t preg;
   struct trusted_list *np;
   str src_ip;
   int_str val;

   src_ip.s = src_ip_c_str;
   src_ip.len = strlen(src_ip.s);

   if (parse_from_header(msg) < 0) return -1;
   uri = get_from(msg)->uri;
   if (uri.len > MAX_URI_SIZE) {
      LM_ERR("from URI too large\n");
      return -1;
   }
   memcpy(uri_string, uri.s, uri.len);
   uri_string[uri.len] = (char)0;

   for (np = table[perm_hash(src_ip)]; np != NULL; np = np->next) {
       if ((np->src_ip.len == src_ip.len) && 
      (strncmp(np->src_ip.s, src_ip.s, src_ip.len) == 0) &&
      ((np->proto == PROTO_NONE) || (np->proto == proto))) {
      if (!(np->pattern)) goto found;
      if (regcomp(&preg, np->pattern, REG_NOSUB)) {
          LM_ERR("invalid regular expression\n");
          return -1;
      }
      if (regexec(&preg, uri_string, 0, (regmatch_t *)0, 0)) {
          regfree(&preg);
      } else {
          regfree(&preg);
          goto found;
      }
       }
   }
   return -1;
found:
   if (tag_avp.n && np->tag.s) {
       val.s = np->tag;
       if (add_avp(tag_avp_type|AVP_VAL_STR, tag_avp, val) != 0) {
      LM_ERR("setting of tag_avp failed\n");
      return -1;
       }
   }
   return 1;
}


/* 
 * Print trusted entries stored in hash table 
 */
int hash_table_mi_print(struct trusted_list** table, struct mi_node* rpl)
{
    int i;
    struct trusted_list *np;
    
    for (i = 0; i < PERM_HASH_SIZE; i++) {
   np = table[i];
   while (np) {
       if (addf_mi_node_child(rpl, 0, 0, 0,
               "%4d <%.*s, %d, %s, %s>",
               i,
               np->src_ip.len, ZSW(np->src_ip.s),
               np->proto,
               np->pattern?np->pattern:"NULL",
               np->tag.len?np->tag.s:"NULL") == 0) {
      return -1;
       }
       np = np->next;
   }
    }
    return 0;
}


/* 
 * Free contents of hash table, it doesn't destroy the
 * hash table itself
 */
void empty_hash_table(struct trusted_list **table)
{
    int i;
    struct trusted_list *np, *next;
    
    for (i = 0; i < PERM_HASH_SIZE; i++) {
   np = table[i];
   while (np) {
       if (np->src_ip.s) shm_free(np->src_ip.s);
       if (np->pattern) shm_free(np->pattern);
       if (np->tag.s) shm_free(np->tag.s);
       next = np->next;
       shm_free(np);
       np = next;
   }
   table[i] = 0;
    }
}


/*
 * Create and initialize an address hash table
 */
struct addr_list** new_addr_hash_table(void)
{
    struct addr_list** ptr;

    /* Initializing hash tables and hash table variable */
    ptr = (struct addr_list **)shm_malloc
   (sizeof(struct addr_list*) * PERM_HASH_SIZE);
    if (!ptr) {
   LM_ERR("no shm memory for hash table\n");
   return 0;
    }

    memset(ptr, 0, sizeof(struct addr_list*) * PERM_HASH_SIZE);
    return ptr;
}


/*
 * Release all memory allocated for a hash table
 */
void free_addr_hash_table(struct addr_list** table)
{
    if (!table)
   return;

    empty_addr_hash_table(table);
    shm_free(table);
}


/* 
 * Add <grp, ip_addr, port> into hash table
 */
int addr_hash_table_insert(struct addr_list** table, unsigned int grp,
            unsigned int ip_addr, unsigned int port)
{
    struct addr_list *np;
    unsigned int hash_val;
    str addr_str;
   
    np = (struct addr_list *) shm_malloc(sizeof(*np));
    if (np == NULL) {
   LM_ERR("no shm memory for table entry\n");
   return -1;
    }

    np->grp = grp;
    np->ip_addr = ip_addr;
    np->port = port;
    
    addr_str.s = (char *)(&ip_addr);
    addr_str.len = 4;
    hash_val = perm_hash(addr_str);
    np->next = table[hash_val];
    table[hash_val] = np;

    return 1;
}


/* 
 * Check if an entry exists in hash table that has given group, ip_addr, and
 * port.  Port 0 in hash table matches any port.
 */
int match_addr_hash_table(struct addr_list** table, unsigned int group,
           unsigned int ip_addr, unsigned int port)
{
   struct addr_list *np;
   str addr_str;

   addr_str.s = (char *)(&ip_addr);
   addr_str.len = 4;

   for (np = table[perm_hash(addr_str)]; np != NULL; np = np->next) {
       if ((np->ip_addr == ip_addr) && (np->grp == group) &&
      ((np->port == 0) || (np->port == port))) {
      return 1;
       }
   }

   return -1;
}


/* 
 * Check if an ip_addr/port entry exists in hash table in any group.
 * Returns first group in which ip_addr/port is found.
 * Port 0 in hash table matches any port. 
 */
int find_group_in_addr_hash_table(struct addr_list** table,
              unsigned int ip_addr, unsigned int port)
{
   struct addr_list *np;
   str addr_str;

   addr_str.s = (char *)(&ip_addr);
   addr_str.len = 4;

   for (np = table[perm_hash(addr_str)]; np != NULL; np = np->next) {
       if ((np->ip_addr == ip_addr) &&
      ((np->port == 0) || (np->port == port))) {
      return np->grp;
       }
   }

   return -1;
}


/* 
 * Print addresses stored in hash table 
 */
int addr_hash_table_mi_print(struct addr_list** table, struct mi_node* rpl)
{
    int i;
    struct addr_list *np;
    struct ip_addr addr;
    
    for (i = 0; i < PERM_HASH_SIZE; i++) {
   np = table[i];
   while (np) {
       addr.af = AF_INET;
       addr.len = 4;
       addr.u.addr32[0] = np->ip_addr;
       if (addf_mi_node_child(rpl, 0, 0, 0,
               "%4d <%u, %s, %u>",
               i, np->grp, ip_addr2a(&addr),
               np->port) == 0)
      return -1;
       np = np->next;
   }
    }
    return 0;
}


/* 
 * Free contents of hash table, it doesn't destroy the
 * hash table itself
 */
void empty_addr_hash_table(struct addr_list **table)
{
    int i;
    struct addr_list *np, *next;

    for (i = 0; i < PERM_HASH_SIZE; i++) {
   np = table[i];
   while (np) {
       next = np->next;
       shm_free(np);
       np = next;
   }
   table[i] = 0;
    }
}


/*
 * Create and initialize a subnet table
 */
struct subnet* new_subnet_table(void)
{
    struct subnet* ptr;

    /* subnet record [PERM_MAX_SUBNETS] contains in its grp field 
       the number of subnet records in the subnet table */
    ptr = (struct subnet *)shm_malloc
   (sizeof(struct subnet) * (PERM_MAX_SUBNETS + 1));
    if (!ptr) {
   LM_ERR("no shm memory for subnet table\n");
   return 0;
    }
    ptr[PERM_MAX_SUBNETS].grp = 0;
    return ptr;
}

    
/* 
 * Add <grp, subnet, mask, port> into subnet table so that table is
 * kept in increasing ordered according to grp.
 */
int subnet_table_insert(struct subnet* table, unsigned int grp,
         unsigned int subnet, unsigned int mask,
         unsigned int port)
{
    int i;
    unsigned int count;

    count = table[PERM_MAX_SUBNETS].grp;

    if (count == PERM_MAX_SUBNETS) {
   LM_CRIT("subnet table is full\n");
   return 0;
    }

    mask = 32 - mask;
    subnet = htonl(ntohl(subnet) >> mask); //subnet << mask;

    i = count - 1;

    while ((i >= 0) && (table[i].grp > grp)) {
   table[i + 1] = table[i];
   i--;
    }
    
    table[i + 1].grp = grp;
    table[i + 1].subnet = subnet;
    table[i + 1].port = port;
    table[i + 1].mask = mask;

    table[PERM_MAX_SUBNETS].grp = count + 1;

    return 1;
}


/* 
 * Check if an entry exists in subnet table that matches given group, ip_addr,
 * and port.  Port 0 in subnet table matches any port.
 */
int match_subnet_table(struct subnet* table, unsigned int grp,
             unsigned int ip_addr, unsigned int port)
{
    unsigned int count, i, subnet;

    count = table[PERM_MAX_SUBNETS].grp;

    i = 0;
    while ((i < count) && (table[i].grp < grp))
   i++;
    
    if (i == count) return -1;

    while ((i < count) && (table[i].grp == grp)) {
   subnet = htonl(ntohl(ip_addr) >> table[i].mask); //ip_addr << table[i].mask;
   if ((table[i].subnet == subnet) &&
       ((table[i].port == port) || (table[i].port == 0)))
       return 1;
   i++;
    }

    return -1;
}


/* 
 * Check if an entry exists in subnet table that matches given ip_addr,
 * and port.  Port 0 in subnet table matches any port.  Return group of
 * first match or -1 if no match is found.
 */
int find_group_in_subnet_table(struct subnet* table,
                unsigned int ip_addr, unsigned int port)
{
    unsigned int count, i, subnet;

    count = table[PERM_MAX_SUBNETS].grp;

    i = 0;
    while (i < count) {
   subnet = ip_addr << table[i].mask;
   if ((table[i].subnet == subnet) &&
       ((table[i].port == port) || (table[i].port == 0)))
       return table[i].grp;
   i++;
    }

    return -1;
}


/* 
 * Print subnets stored in subnet table 
 */
int subnet_table_mi_print(struct subnet* table, struct mi_node* rpl)
{
    unsigned int count, i;
    struct ip_addr addr;
    
    count = table[PERM_MAX_SUBNETS].grp;

    for (i = 0; i < count; i++) {
   addr.af = AF_INET;
   addr.len = 4;
   addr.u.addr32[0] = htonl(ntohl(table[i].subnet) << table[i].mask); //table[i].subnet >> table[i].mask;
   if (addf_mi_node_child(rpl, 0, 0, 0,
                "%4d <%u, %s, %u, %u>",
                i, table[i].grp, ip_addr2a(&addr),
                32 - table[i].mask, table[i].port) == 0) {
       return -1;
   }
    }
    return 0;
}


/* 
 * Empty contents of subnet table
 */
void empty_subnet_table(struct subnet *table)
{
    table[PERM_MAX_SUBNETS].grp = 0;
}


/*
 * Release memory allocated for a subnet table
 */
void free_subnet_table(struct subnet* table)
{
    if (!table)
   return;

    shm_free(table);
}