| /* |
| * IP address pool functions. |
| * Copyright (C) 2003 Mondru AB. |
| * |
| * The contents of this file may be used under the terms of the GNU |
| * General Public License Version 2, provided that the above copyright |
| * notice and this permission notice is included in all copies or |
| * substantial portions of the software. |
| * |
| * The initial developer of the original code is |
| * Jens Jakobsen <jj@openggsn.org> |
| * |
| * Contributor(s): |
| * |
| */ |
| |
| #include <netinet/in.h> /* in_addr */ |
| #include <stdlib.h> /* calloc */ |
| #include <stdio.h> /* sscanf */ |
| |
| #include "ippool.h" |
| |
| |
| /* |
| -------------------------------------------------------------------- |
| Public domain by From Bob Jenkins, December 1996. |
| mix -- mix 3 32-bit values reversibly. |
| For every delta with one or two bit set, and the deltas of all three |
| high bits or all three low bits, whether the original value of a,b,c |
| is almost all zero or is uniformly distributed, |
| * If mix() is run forward or backward, at least 32 bits in a,b,c |
| have at least 1/4 probability of changing. |
| * If mix() is run forward, every bit of c will change between 1/3 and |
| 2/3 of the time. (Well, 22/100 and 78/100 for some 2-bit deltas.) |
| mix() was built out of 36 single-cycle latency instructions in a |
| structure that could supported 2x parallelism, like so: |
| a -= b; |
| a -= c; x = (c>>13); |
| b -= c; a ^= x; |
| b -= a; x = (a<<8); |
| c -= a; b ^= x; |
| c -= b; x = (b>>13); |
| ... |
| Unfortunately, superscalar Pentiums and Sparcs can't take advantage |
| of that parallelism. They've also turned some of those single-cycle |
| latency instructions into multi-cycle latency instructions. Still, |
| this is the fastest good hash I could find. There were about 2^^68 |
| to choose from. I only looked at a billion or so. |
| -------------------------------------------------------------------- |
| */ |
| #define mix(a,b,c) \ |
| { \ |
| a -= b; a -= c; a ^= (c>>13); \ |
| b -= c; b -= a; b ^= (a<<8); \ |
| c -= a; c -= b; c ^= (b>>13); \ |
| a -= b; a -= c; a ^= (c>>12); \ |
| b -= c; b -= a; b ^= (a<<16); \ |
| c -= a; c -= b; c ^= (b>>5); \ |
| a -= b; a -= c; a ^= (c>>3); \ |
| b -= c; b -= a; b ^= (a<<10); \ |
| c -= a; c -= b; c ^= (b>>15); \ |
| } |
| /* |
| -------------------------------------------------------------------- |
| lookup() -- hash a variable-length key into a 32-bit value |
| k : the key (the unaligned variable-length array of bytes) |
| len : the length of the key, counting by bytes |
| level : can be any 4-byte value |
| Returns a 32-bit value. Every bit of the key affects every bit of |
| the return value. Every 1-bit and 2-bit delta achieves avalanche. |
| About 6len+35 instructions. |
| |
| The best hash table sizes are powers of 2. There is no need to do |
| mod a prime (mod is sooo slow!). If you need less than 32 bits, |
| use a bitmask. For example, if you need only 10 bits, do |
| h = (h & hashmask(10)); |
| In which case, the hash table should have hashsize(10) elements. |
| |
| If you are hashing n strings (ub1 **)k, do it like this: |
| for (i=0, h=0; i<n; ++i) h = lookup( k[i], len[i], h); |
| |
| By Bob Jenkins, 1996. bob_jenkins@burtleburtle.net. You may use this |
| code any way you wish, private, educational, or commercial. |
| |
| See http://burtleburtle.net/bob/hash/evahash.html |
| Use for hash table lookup, or anything where one collision in 2^32 is |
| acceptable. Do NOT use for cryptographic purposes. |
| -------------------------------------------------------------------- |
| */ |
| |
| unsigned long int lookup( k, length, level) |
| register unsigned char *k; /* the key */ |
| register unsigned long int length; /* the length of the key */ |
| register unsigned long int level; /* the previous hash, or an arbitrary value */ |
| { |
| register unsigned long int a,b,c,len; |
| |
| /* Set up the internal state */ |
| len = length; |
| a = b = 0x9e3779b9; /* the golden ratio; an arbitrary value */ |
| c = level; /* the previous hash value */ |
| |
| /*---------------------------------------- handle most of the key */ |
| while (len >= 12) |
| { |
| a += (k[0] +((ub4)k[1]<<8) +((ub4)k[2]<<16) +((ub4)k[3]<<24)); |
| b += (k[4] +((ub4)k[5]<<8) +((ub4)k[6]<<16) +((ub4)k[7]<<24)); |
| c += (k[8] +((ub4)k[9]<<8) +((ub4)k[10]<<16)+((ub4)k[11]<<24)); |
| mix(a,b,c); |
| k += 12; len -= 12; |
| } |
| |
| /*------------------------------------- handle the last 11 bytes */ |
| c += length; |
| switch(len) /* all the case statements fall through */ |
| { |
| case 11: c+=((ub4)k[10]<<24); |
| case 10: c+=((ub4)k[9]<<16); |
| case 9 : c+=((ub4)k[8]<<8); |
| /* the first byte of c is reserved for the length */ |
| case 8 : b+=((ub4)k[7]<<24); |
| case 7 : b+=((ub4)k[6]<<16); |
| case 6 : b+=((ub4)k[5]<<8); |
| case 5 : b+=k[4]; |
| case 4 : a+=((ub4)k[3]<<24); |
| case 3 : a+=((ub4)k[2]<<16); |
| case 2 : a+=((ub4)k[1]<<8); |
| case 1 : a+=k[0]; |
| /* case 0: nothing left to add */ |
| } |
| mix(a,b,c); |
| /*-------------------------------------------- report the result */ |
| return c; |
| } |
| |
| /* |
| End of public domain code by From Bob Jenkins, December 1996. |
| -------------------------------------------------------------------- |
| */ |
| |
| int ippool_printaddr(struct ippool_t *this) { |
| int n; |
| printf("ippool_printaddr\n"); |
| printf("First %d\n", this->first - this->member); |
| printf("Last %d\n", this->last - this->member); |
| printf("Listsize %d\n", this->listsize); |
| |
| for (n=0; n<this->listsize; n++) { |
| printf("Unit %d inuse %d prev %d next %d addr %x\n", |
| n, |
| this->member[n].inuse, |
| this->member[n].prev - this->member, |
| this->member[n].next - this->member, |
| this->member[n].addr.s_addr |
| ); |
| } |
| return 0; |
| } |
| |
| |
| unsigned long int ippool_hash4(struct in_addr *addr) { |
| return lookup(&addr->s_addr, sizeof(addr->s_addr), 0); |
| } |
| |
| #ifndef IPPOOL_NOIP6 |
| unsigned long int ippool_hash6(struct in6_addr *addr) { |
| return lookup(addr->u6_addr8, sizeof(addr->u6_addr8), 0); |
| } |
| #endif |
| |
| |
| /* Get IP address and mask */ |
| int ippool_aton(struct in_addr *addr, struct in_addr *mask, |
| char *pool, int number) { |
| |
| /* Parse only first instance of network for now */ |
| /* Eventually "number" will indicate the token which we want to parse */ |
| |
| unsigned int a1, a2, a3, a4; |
| unsigned int m1, m2, m3, m4; |
| int c; |
| unsigned int m; |
| int masklog; |
| |
| c = sscanf(pool, "%u.%u.%u.%u/%u.%u.%u.%u", |
| &a1, &a2, &a3, &a4, |
| &m1, &m2, &m3, &m4); |
| switch (c) { |
| case 4: |
| if (a1 == 0 && a2 == 0 && a3 == 0 && a4 == 0) /* Full Internet */ |
| mask->s_addr = 0x00000000; |
| else if (a2 == 0 && a3 == 0 && a4 == 0) /* class A */ |
| mask->s_addr = htonl(0xff000000); |
| else if (a3 == 0 && a4 == 0) /* class B */ |
| mask->s_addr = htonl(0xffff0000); |
| else if (a4 == 0) /* class C */ |
| mask->s_addr = htonl(0xffffff00); |
| else |
| mask->s_addr = 0xffffffff; |
| break; |
| case 5: |
| if (m1 < 0 || m1 > 32) { |
| return -1; /* Invalid mask */ |
| } |
| mask->s_addr = htonl(0xffffffff << (32 - m1)); |
| break; |
| case 8: |
| if (m1 >= 256 || m2 >= 256 || m3 >= 256 || m4 >= 256) |
| return -1; /* Wrong mask format */ |
| m = m1 * 0x1000000 + m2 * 0x10000 + m3 * 0x100 + m4; |
| for (masklog = 0; ((1 << masklog) < ((~m)+1)); masklog++); |
| if (((~m)+1) != (1 << masklog)) |
| return -1; /* Wrong mask format (not all ones followed by all zeros)*/ |
| mask->s_addr = htonl(m); |
| break; |
| default: |
| return -1; /* Invalid mask */ |
| } |
| |
| if (a1 >= 256 || a2 >= 256 || a3 >= 256 || a4 >= 256) |
| return -1; /* Wrong IP address format */ |
| else |
| addr->s_addr = htonl(a1 * 0x1000000 + a2 * 0x10000 + a3 * 0x100 + a4); |
| |
| return 0; |
| } |
| |
| /* Create new address pool */ |
| int ippool_new(struct ippool_t **this, char *pool, int flags) { |
| |
| /* Parse only first instance of network for now */ |
| |
| int i; |
| struct ippoolm_t *p; |
| struct ippoolm_t *p_prev = NULL; |
| uint32_t hash; |
| struct in_addr addr; |
| struct in_addr mask; |
| unsigned int m; |
| unsigned int listsize; |
| |
| if (ippool_aton(&addr, &mask, pool, 0)) |
| return 0; /* Failed to parse pool */ |
| |
| m = ntohl(mask.s_addr); |
| listsize = ((~m)+1); |
| if (flags & IPPOOL_NONETWORK) /* Exclude network address from pool */ |
| listsize--; |
| if (flags & IPPOOL_NOBROADCAST) /* Exclude broadcast address from pool */ |
| listsize--; |
| |
| if (!(*this = calloc(sizeof(struct ippool_t), 1))) { |
| /* Failed to allocate memory for ippool */ |
| return -1; |
| } |
| |
| (*this)->listsize += listsize; |
| if (!((*this)->member = calloc(sizeof(struct ippoolm_t), (*this)->listsize))){ |
| /* Failed to allocate memory for members in ippool */ |
| return -1; |
| } |
| |
| for ((*this)->hashlog = 0; |
| ((1 << (*this)->hashlog) < listsize); |
| (*this)->hashlog++); |
| |
| /* printf ("Hashlog %d %d %d\n", (*this)->hashlog, listsize, (1 << (*this)->hashlog)); */ |
| |
| /* Determine hashsize */ |
| (*this)->hashsize = 1 << (*this)->hashlog; /* Fails if mask=0: All Internet*/ |
| (*this)->hashmask = (*this)->hashsize -1; |
| |
| /* Allocate hash table */ |
| if (!((*this)->hash = calloc(sizeof(struct ippoolm_t), (*this)->hashsize))){ |
| /* Failed to allocate memory for hash members in ippool */ |
| return -1; |
| } |
| |
| (*this)->first = NULL; |
| (*this)->last = NULL; |
| for (i = 0; i<(*this)->listsize; i++) { |
| |
| if (flags & IPPOOL_NONETWORK) |
| (*this)->member[i].addr.s_addr = htonl(ntohl(addr.s_addr) + i + 1); |
| else |
| (*this)->member[i].addr.s_addr = htonl(ntohl(addr.s_addr) + i); |
| |
| (*this)->member[i].inuse = 0; |
| (*this)->member[i].parent = *this; |
| |
| /* Insert into list of unused */ |
| (*this)->member[i].prev = (*this)->last; |
| if ((*this)->last) { |
| (*this)->last->next = &((*this)->member[i]); |
| } |
| else { |
| (*this)->first = &((*this)->member[i]); |
| } |
| (*this)->last = &((*this)->member[i]); |
| (*this)->member[i].next = NULL; /* Redundant */ |
| |
| /* Insert into hash table */ |
| hash = ippool_hash4(&(*this)->member[i].addr) & (*this)->hashmask; |
| for (p = (*this)->hash[hash]; p; p = p->nexthash) |
| p_prev = p; |
| if (!p_prev) |
| (*this)->hash[hash] = &((*this)->member[i]); |
| else |
| p_prev->nexthash = &((*this)->member[i]); |
| } |
| /*ippool_printaddr(*this);*/ |
| return 0; |
| } |
| |
| /* Delete existing address pool */ |
| int ippool_free(struct ippool_t *this) { |
| free(this->hash); |
| free(this->member); |
| free(this); |
| return 0; /* Always OK */ |
| } |
| |
| /* Find an IP address in the pool */ |
| int ippool_getip(struct ippool_t *this, struct ippoolm_t **member, |
| struct in_addr *addr) { |
| struct ippoolm_t *p; |
| uint32_t hash; |
| |
| /* Find in hash table */ |
| hash = ippool_hash4(addr) & this->hashmask; |
| for (p = this->hash[hash]; p; p = p->nexthash) { |
| if ((p->addr.s_addr == addr->s_addr) && (p->inuse)) { |
| *member = p; |
| return 0; |
| } |
| } |
| *member = NULL; |
| return -1; /* Address could not be found */ |
| } |
| |
| |
| /* Get an IP address. If addr = 0.0.0.0 get a dynamic IP address. Otherwise |
| check to see if the given address is available */ |
| int ippool_newip(struct ippool_t *this, struct ippoolm_t **member, |
| struct in_addr *addr) { |
| struct ippoolm_t *p; |
| struct ippoolm_t *p2 = NULL; |
| uint32_t hash; |
| |
| /*ippool_printaddr(this);*/ |
| |
| if ((addr) && (addr->s_addr)) { /* IP address given */ |
| /* Find in hash table */ |
| hash = ippool_hash4(addr) & this->hashmask; |
| for (p = this->hash[hash]; p; p = p->nexthash) { |
| if ((p->addr.s_addr == addr->s_addr)) { |
| p2 = p; |
| break; |
| } |
| } |
| } |
| else { /* No ip address given */ |
| p2 = this -> first; |
| } |
| |
| if (!p2) return -1; /* Not found */ |
| if (p2->inuse) return -1; /* Allready in use / Should not happen */ |
| |
| /* Found new address. Remove from queue */ |
| if (p2->prev) |
| p2->prev->next = p2->next; |
| else |
| this->first = p2->next; |
| if (p2->next) |
| p2->next->prev = p2->prev; |
| else |
| this->last = p2->prev; |
| p2->next = NULL; |
| p2->prev = NULL; |
| p2->inuse = 1; |
| |
| *member = p2; |
| /*ippool_printaddr(this);*/ |
| return 0; /* Success */ |
| } |
| |
| |
| int ippool_freeip(struct ippoolm_t *member) { |
| struct ippool_t *this = member->parent; |
| |
| /*ippool_printaddr(this);*/ |
| |
| if (!member->inuse) return -1; /* Not in use: Should not happen */ |
| |
| /* Insert into list of unused */ |
| member->prev = this->last; |
| if (this->last) { |
| this->last->next = member; |
| } |
| else { |
| this->first = member; |
| } |
| this->last = member; |
| |
| member->inuse = 0; |
| /*ippool_printaddr(this);*/ |
| |
| return 0; /* Success */ |
| } |
| |
| |
| #ifndef IPPOOL_NOIP6 |
| extern unsigned long int ippool_hash6(struct in6_addr *addr); |
| extern int ippool_getip6(struct ippool_t *this, struct in6_addr *addr); |
| extern int ippool_returnip6(struct ippool_t *this, struct in6_addr *addr); |
| #endif |