diff options
author | jjako <jjako> | 2003-04-11 09:40:12 +0000 |
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committer | jjako <jjako> | 2003-04-11 09:40:12 +0000 |
commit | a7cd249501b869ed518746b301eb92230ec50f50 (patch) | |
tree | 685d542efae0d9e14c1bd21ecb64117521f8c5a9 /sgsnemu/ippool.c | |
parent | afb2a970de8bcc78142bf0a40a8481012a6d2f34 (diff) |
added ippool.h and ippool.c
Diffstat (limited to 'sgsnemu/ippool.c')
-rw-r--r-- | sgsnemu/ippool.c | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/sgsnemu/ippool.c b/sgsnemu/ippool.c new file mode 100644 index 0000000..3ad5c04 --- /dev/null +++ b/sgsnemu/ippool.c @@ -0,0 +1,416 @@ +/* + * 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 |