lib/ippool.h

   1 /*
   2  * IP address pool functions.
   3  * Copyright (C) 2003, 2004 Mondru AB.
   4  *
   5  * The contents of this file may be used under the terms of the GNU
   6  * General Public License Version 2, provided that the above copyright
   7  * notice and this permission notice is included in all copies or
   8  * substantial portions of the software.
   9  *
  10  */
  11
  12 #ifndef _IPPOOL_H
  13 #define _IPPOOL_H
  14
  15 /* Assuming that the address space is fragmented we need a hash table
  16    in order to return the addresses.
  17
  18    The list pool should provide for both IPv4 and IPv6 addresses.
  19
  20    When initialising a new address pool it should be possible to pass
  21    a string of CIDR format networks: "10.0.0.0/24 10.15.0.0/20" would
  22    translate to 256 addresses starting at 10.0.0.0 and 1024 addresses
  23    starting at 10.15.0.0.
  24
  25    The above also applies to IPv6 which can be specified as described
  26    in RFC2373.
  27 */
  28
  29 #define IPPOOL_NOIP6
  30
  31 #define IPPOOL_NONETWORK   0x01
  32 #define IPPOOL_NOBROADCAST 0x02
  33 #define IPPOOL_NOGATEWAY   0x04
  34
  35 #define IPPOOL_STATSIZE 0x10000
  36
  37 struct ippoolm_t;               /* Forward declaration */
  38
  39 struct ippool_t {
  40         unsigned int listsize;  /* Total number of addresses */
  41         int allowdyn;           /* Allow dynamic IP address allocation */
  42         int allowstat;          /* Allow static IP address allocation */
  43         struct in_addr stataddr;        /* Static address range network address */
  44         struct in_addr statmask;        /* Static address range network mask */
  45         struct ippoolm_t *member;       /* Listsize array of members */
  46         unsigned int hashsize;  /* Size of hash table */
  47         int hashlog;            /* Log2 size of hash table */
  48         int hashmask;           /* Bitmask for calculating hash */
  49         struct ippoolm_t **hash;        /* Hashsize array of pointer to member */
  50         struct ippoolm_t *firstdyn;     /* Pointer to first free dynamic member */
  51         struct ippoolm_t *lastdyn;      /* Pointer to last free dynamic member */
  52         struct ippoolm_t *firststat;    /* Pointer to first free static member */
  53         struct ippoolm_t *laststat;     /* Pointer to last free static member */
  54 };
  55
  56 struct ippoolm_t {
  57 #ifndef IPPOOL_NOIP6
  58         struct in6_addr addr;   /* IP address of this member */
  59 #else
  60         struct in_addr addr;    /* IP address of this member */
  61 #endif
  62         int inuse;              /* 0=available; 1= dynamic; 2 = static */
  63         struct ippoolm_t *nexthash;     /* Linked list part of hash table */
  64         struct ippoolm_t *prev, *next;  /* Linked list of free dynamic or static */
  65         void *peer;             /* Pointer to peer protocol handler */
  66 };
  67
  68 /* The above structures require approximately 20+4 = 24 bytes for
  69    each address (IPv4). For IPv6 the corresponding value is 32+4 = 36
  70    bytes for each address. */
  71
  72 /* Hash an IP address using code based on Bob Jenkins lookupa */
  73 extern unsigned long int ippool_hash4(struct in_addr *addr);
  74
  75 /* Create new address pool */
  76 extern int ippool_new(struct ippool_t **this, char *dyn, char *stat,
  77                       int allowdyn, int allowstat, int flags);
  78
  79 /* Delete existing address pool */
  80 extern int ippool_free(struct ippool_t *this);
  81
  82 /* Find an IP address in the pool */
  83 extern int ippool_getip(struct ippool_t *this, struct ippoolm_t **member,
  84                         struct in_addr *addr);
  85
  86 /* Get an IP address. If addr = 0.0.0.0 get a dynamic IP address. Otherwise
  87    check to see if the given address is available */
  88 extern int ippool_newip(struct ippool_t *this, struct ippoolm_t **member,
  89                         struct in_addr *addr, int statip);
  90
  91 /* Return a previously allocated IP address */
  92 extern int ippool_freeip(struct ippool_t *this, struct ippoolm_t *member);
  93
  94 /* Get net and mask based on ascii string */
  95 extern int ippool_aton(struct in_addr *addr, struct in_addr *mask,
  96                        char *pool, int number);
  97
  98 #ifndef IPPOOL_NOIP6
  99 extern unsigned long int ippool_hash6(struct in6_addr *addr);
 100 extern int ippool_getip6(struct ippool_t *this, struct in6_addr *addr);
 101 extern int ippool_returnip6(struct ippool_t *this, struct in6_addr *addr);
 102 #endif
 103
 104 #endif /* !_IPPOOL_H */