MG Mud User | 88f1247 | 2016-06-24 23:31:02 +0200 | [diff] [blame^] | 1 | // MorgenGrauen MUDlib |
| 2 | /** \file /secure/master/cidr.c |
| 3 | * Funktionen zur Interpretation und Umrechnung von IP-Adressen in CIDR-Notation. |
| 4 | * \author Zesstra |
| 5 | * \date 05.02.2010 |
| 6 | * \version $Id$ |
| 7 | */ |
| 8 | /* Changelog: |
| 9 | */ |
| 10 | |
| 11 | private int IPv4_addr2int(string addr) { |
| 12 | int mask; |
| 13 | |
| 14 | if (!stringp(addr) || !sizeof(addr)) |
| 15 | return 0; |
| 16 | // irgendwelche Zeichen ausser 0-9, . und / drin? |
| 17 | if (sizeof(addr-"0123456789./")) |
| 18 | return 0; |
| 19 | |
| 20 | string *parts = explode(addr, "/") - ({""}); |
| 21 | // Netzmaske gegeben? -> Netzwerkadresse bestimmen |
| 22 | if (sizeof(parts) == 2) { |
| 23 | // a.b.c.d/x oder a.b.c.d/w.x.y.z |
| 24 | int res = IPv4_addr2int(parts[0]); // erstmal Wert von a.b.c.d... |
| 25 | if (strstr(parts[1], ".") > -1 |
| 26 | && sizeof(explode(parts[1],".")) == 4) |
| 27 | // a.b.c.d/w.x.y.z -> Wert von w.x.y.z bestimmen |
| 28 | mask = IPv4_addr2int(parts[1]); |
| 29 | else { |
| 30 | mask = to_int(parts[1]); |
| 31 | // Wert von /x |
| 32 | mask = 0xffffffff - (to_int(pow(2, 32-mask))-1); |
| 33 | } |
| 34 | // verunden und Ende. |
| 35 | return res & mask; |
| 36 | } |
| 37 | |
| 38 | parts = explode(parts[0], "."); |
| 39 | // Abgrekuerzte Adresse a la a.b.? Rest mit 0 ergaenzen. |
| 40 | switch(sizeof(parts - ({""})) ) { |
| 41 | case 1: |
| 42 | parts += ({"0","0","0"}); |
| 43 | case 2: |
| 44 | parts += ({"0","0"}); |
| 45 | case 3: |
| 46 | parts += ({"0"}); |
| 47 | case 4: |
| 48 | break; |
| 49 | default: |
| 50 | return 0; |
| 51 | } |
| 52 | |
| 53 | return( to_int(parts[0]) << 24) |
| 54 | + ( to_int(parts[1]) << 16) |
| 55 | + ( to_int(parts[2]) << 8 ) |
| 56 | + to_int(parts[3]); |
| 57 | } |
| 58 | |
| 59 | private int IPv4_net_size(string addr) { |
| 60 | if (!stringp(addr) || !sizeof(addr)) |
| 61 | return 0; |
| 62 | // irgendwelche Zeichen ausser 0-9, . und / drin? |
| 63 | if (sizeof(addr-"0123456789./")) |
| 64 | return 0; |
| 65 | |
| 66 | string *parts = explode(addr, "/") - ({""}); |
| 67 | // Netzmaske gegeben? -> Netzwerkadresse bestimmen |
| 68 | if (sizeof(parts) == 2) { |
| 69 | // a.b.c.d/x oder a.b.c.d/w.x.y.z |
| 70 | if (strstr(parts[1], ".") > -1 |
| 71 | && sizeof(explode(parts[1],".")) == 4) |
| 72 | // a.b.c.d/w.x.y.z |
| 73 | return 0xffffffff - (IPv4_addr2int(parts[1]) || 1) + 1; |
| 74 | else { |
| 75 | // Einfach 2^(32-mask) Adressen. |
| 76 | return to_int(pow(2, 32 - to_int(parts[1]) ) ); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | parts = explode(parts[0], "."); |
| 81 | switch(sizeof(parts - ({""})) ) { |
| 82 | case 1: // Class A |
| 83 | return 256*256*256; |
| 84 | case 2: // Class B |
| 85 | return 256*256; |
| 86 | case 3: // Class C |
| 87 | return 256; |
| 88 | case 4: // einzelne Adresse |
| 89 | return 1; |
| 90 | default: // ungueltige Adresse |
| 91 | return __INT_MAX__; |
| 92 | } |
| 93 | |
| 94 | // hier sollte man gar nicht ankommen. |
| 95 | return __INT_MAX__; |
| 96 | } |
| 97 | |
| 98 | string IPv4_int2addr(int ip) { |
| 99 | int *parts=allocate(4); |
| 100 | parts[0] = (ip & 0xff000000) >> 24; |
| 101 | parts[1] = (ip & 0x00ff0000) >> 16; |
| 102 | parts[2] = (ip & 0x0000ff00) >> 8; |
| 103 | parts[3] = (ip & 0x000000ff); |
| 104 | // int is signed. Anything > 127 would wrap around to -128 if we are on a |
| 105 | // machine with 32-bit wide ints. |
| 106 | if (parts[0] < 0) |
| 107 | parts[0] = 128 + (128-abs(parts[0])); |
| 108 | |
| 109 | return implode(map(parts,#'to_string), "."); |
| 110 | } |
| 111 | |