/* * BIRD Library -- IP address functions * * (c) 1998--2000 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ /** * DOC: IP addresses * * BIRD uses its own abstraction of IP address in order to share the same * code for both IPv4 and IPv6. IP addresses are represented as entities * of type &ip_addr which are never to be treated as numbers and instead * they must be manipulated using the following functions and macros. */ #include <stdlib.h> #include "nest/bird.h" #include "lib/ip.h" int ip6_compare(ip6_addr a, ip6_addr b) { int i; for (i=0; i<4; i++) if (a.addr[i] > b.addr[i]) return 1; else if (a.addr[i] < b.addr[i]) return -1; return 0; } ip6_addr ip6_mkmask(uint n) { ip6_addr a; int i; for (i=0; i<4; i++) { if (!n) a.addr[i] = 0; else if (n >= 32) { a.addr[i] = ~0; n -= 32; } else { a.addr[i] = u32_mkmask(n); n = 0; } } return a; } int ip6_masklen(ip6_addr *a) { int i, j, n; for (i=0, n=0; i<4; i++, n+=32) if (a->addr[i] != ~0U) { j = u32_masklen(a->addr[i]); if (j < 0) return j; n += j; while (++i < 4) if (a->addr[i]) return -1; break; } return n; } int ip4_classify(ip4_addr ad) { u32 a = _I(ad); u32 b = a >> 24U; if (b && b <= 0xdf) { if (b == 0x7f) return IADDR_HOST | SCOPE_HOST; else if ((b == 0x0a) || ((a & 0xffff0000) == 0xc0a80000) || ((a & 0xfff00000) == 0xac100000)) return IADDR_HOST | SCOPE_SITE; else return IADDR_HOST | SCOPE_UNIVERSE; } if (b >= 0xe0 && b <= 0xef) return IADDR_MULTICAST | SCOPE_UNIVERSE; if (a == 0xffffffff) return IADDR_BROADCAST | SCOPE_LINK; return IADDR_INVALID; } int ip6_classify(ip6_addr *a) { u32 x = a->addr[0]; if ((x & 0xe0000000) == 0x20000000) /* 2000::/3 Aggregatable Global Unicast Address */ return IADDR_HOST | SCOPE_UNIVERSE; if ((x & 0xffc00000) == 0xfe800000) /* fe80::/10 Link-Local Address */ return IADDR_HOST | SCOPE_LINK; if ((x & 0xffc00000) == 0xfec00000) /* fec0::/10 Site-Local Address */ return IADDR_HOST | SCOPE_SITE; if ((x & 0xfe000000) == 0xfc000000) /* fc00::/7 Unique Local Unicast Address (RFC 4193) */ return IADDR_HOST | SCOPE_SITE; if ((x & 0xff000000) == 0xff000000) /* ff00::/8 Multicast Address */ { uint scope = (x >> 16) & 0x0f; switch (scope) { case 1: return IADDR_MULTICAST | SCOPE_HOST; case 2: return IADDR_MULTICAST | SCOPE_LINK; case 5: return IADDR_MULTICAST | SCOPE_SITE; case 8: return IADDR_MULTICAST | SCOPE_ORGANIZATION; case 14: return IADDR_MULTICAST | SCOPE_UNIVERSE; default: return IADDR_MULTICAST | SCOPE_UNDEFINED; } } if (!x && !a->addr[1]) { u32 a2 = a->addr[2]; u32 a3 = a->addr[3]; if (a2 == 0 && a3 == 1) return IADDR_HOST | SCOPE_HOST; /* Loopback address */ if (a2 == 0) return ip4_classify(_MI4(a3)); /* IPv4 compatible addresses */ if (a2 == 0xffff) return ip4_classify(_MI4(a3)); /* IPv4 mapped addresses */ return IADDR_INVALID; } return IADDR_HOST | SCOPE_UNDEFINED; } /* * Conversion of IPv6 address to presentation format and vice versa. * Heavily inspired by routines written by Paul Vixie for the BIND project * and of course by RFC 2373. */ char * ip4_ntop(ip4_addr a, char *b) { u32 x = _I(a); return b + bsprintf(b, "%d.%d.%d.%d", (x >> 24) & 0xff, (x >> 16) & 0xff, (x >> 8) & 0xff, x & 0xff); } char * ip6_ntop(ip6_addr a, char *b) { u16 words[8]; int bestpos, bestlen, curpos, curlen, i; /* First of all, preprocess the address and find the longest run of zeros */ bestlen = bestpos = curpos = curlen = 0; for (i=0; i<8; i++) { u32 x = a.addr[i/2]; words[i] = ((i%2) ? x : (x >> 16)) & 0xffff; if (words[i]) curlen = 0; else { if (!curlen) curpos = i; curlen++; if (curlen > bestlen) { bestpos = curpos; bestlen = curlen; } } } if (bestlen < 2) bestpos = -1; /* Is it an encapsulated IPv4 address? */ if (!bestpos && ((bestlen == 5 && a.addr[2] == 0xffff) || (bestlen == 6))) { u32 x = a.addr[3]; b += bsprintf(b, "::%s%d.%d.%d.%d", a.addr[2] ? "ffff:" : "", (x >> 24) & 0xff, (x >> 16) & 0xff, (x >> 8) & 0xff, x & 0xff); return b; } /* Normal IPv6 formatting, compress the largest sequence of zeros */ for (i=0; i<8; i++) { if (i == bestpos) { i += bestlen - 1; *b++ = ':'; if (i == 7) *b++ = ':'; } else { if (i) *b++ = ':'; b += bsprintf(b, "%x", words[i]); } } *b = 0; return b; } int ip4_pton(char *a, ip4_addr *o) { int i; unsigned long int l; u32 ia = 0; i=4; while (i--) { char *d, *c = strchr(a, '.'); if (!c != !i) return 0; l = strtoul(a, &d, 10); if (((d != c) && *d) || (l > 255)) return 0; ia = (ia << 8) | l; if (c) c++; a = c; } *o = ip4_from_u32(ia); return 1; } int ip6_pton(char *a, ip6_addr *o) { u16 words[8]; int i, j, k, l, hfil; char *start; if (a[0] == ':') /* Leading :: */ { if (a[1] != ':') return 0; a++; } hfil = -1; i = 0; while (*a) { if (*a == ':') /* :: */ { if (hfil >= 0) return 0; hfil = i; a++; continue; } j = 0; l = 0; start = a; for (;;) { if (*a >= '0' && *a <= '9') k = *a++ - '0'; else if (*a >= 'A' && *a <= 'F') k = *a++ - 'A' + 10; else if (*a >= 'a' && *a <= 'f') k = *a++ - 'a' + 10; else break; j = (j << 4) + k; if (j >= 0x10000 || ++l > 4) return 0; } if (*a == ':' && a[1]) a++; else if (*a == '.' && (i == 6 || i < 6 && hfil >= 0)) { /* Embedded IPv4 address */ ip4_addr x; if (!ip4_pton(start, &x)) return 0; words[i++] = _I(x) >> 16; words[i++] = _I(x); break; } else if (*a) return 0; if (i >= 8) return 0; words[i++] = j; } /* Replace :: with an appropriate number of zeros */ if (hfil >= 0) { j = 8 - i; for (i=7; i-j >= hfil; i--) words[i] = words[i-j]; for (; i>=hfil; i--) words[i] = 0; } /* Convert the address to ip6_addr format */ for (i=0; i<4; i++) o->addr[i] = (words[2*i] << 16) | words[2*i+1]; return 1; } /** * ip_scope_text - get textual representation of address scope * @scope: scope (%SCOPE_xxx) * * Returns a pointer to a textual name of the scope given. */ char * ip_scope_text(uint scope) { static char *scope_table[] = { "host", "link", "site", "org", "univ", "undef" }; if (scope > SCOPE_UNDEFINED) return "?"; else return scope_table[scope]; } ip4_addr ip4_class_mask(ip4_addr ad) { u32 m, a = _I(ad); if (a < 0x80000000) m = 0xff000000; else if (a < 0xc0000000) m = 0xffff0000; else m = 0xffffff00; if (a & ~m) m = 0xffffffff; return _MI4(m); } #if 0 /** * ipa_equal - compare two IP addresses for equality * @x: IP address * @y: IP address * * ipa_equal() returns 1 if @x and @y represent the same IP address, else 0. */ int ipa_equal(ip_addr x, ip_addr y) { DUMMY } /** * ipa_nonzero - test if an IP address is defined * @x: IP address * * ipa_nonzero returns 1 if @x is a defined IP address (not all bits are zero), * else 0. * * The undefined all-zero address is reachable as a |IPA_NONE| macro. */ int ipa_nonzero(ip_addr x) { DUMMY } /** * ipa_and - compute bitwise and of two IP addresses * @x: IP address * @y: IP address * * This function returns a bitwise and of @x and @y. It's primarily * used for network masking. */ ip_addr ipa_and(ip_addr x, ip_addr y) { DUMMY } /** * ipa_or - compute bitwise or of two IP addresses * @x: IP address * @y: IP address * * This function returns a bitwise or of @x and @y. */ ip_addr ipa_or(ip_addr x, ip_addr y) { DUMMY } /** * ipa_xor - compute bitwise xor of two IP addresses * @x: IP address * @y: IP address * * This function returns a bitwise xor of @x and @y. */ ip_addr ipa_xor(ip_addr x, ip_addr y) { DUMMY } /** * ipa_not - compute bitwise negation of two IP addresses * @x: IP address * * This function returns a bitwise negation of @x. */ ip_addr ipa_not(ip_addr x) { DUMMY } /** * ipa_mkmask - create a netmask * @x: prefix length * * This function returns an &ip_addr corresponding of a netmask * of an address prefix of size @x. */ ip_addr ipa_mkmask(int x) { DUMMY } /** * ipa_masklen - calculate netmask length * @x: IP address * * This function checks whether @x represents a valid netmask and * returns the size of the associate network prefix or -1 for invalid * mask. */ int ipa_masklen(ip_addr x) { DUMMY } /** * ipa_hash - hash IP addresses * @x: IP address * * ipa_hash() returns a 16-bit hash value of the IP address @x. */ int ipa_hash(ip_addr x) { DUMMY } /** * ipa_hton - convert IP address to network order * @x: IP address * * Converts the IP address @x to the network byte order. * * Beware, this is a macro and it alters the argument! */ void ipa_hton(ip_addr x) { DUMMY } /** * ipa_ntoh - convert IP address to host order * @x: IP address * * Converts the IP address @x from the network byte order. * * Beware, this is a macro and it alters the argument! */ void ipa_ntoh(ip_addr x) { DUMMY } /** * ipa_classify - classify an IP address * @x: IP address * * ipa_classify() returns an address class of @x, that is a bitwise or * of address type (%IADDR_INVALID, %IADDR_HOST, %IADDR_BROADCAST, %IADDR_MULTICAST) * with address scope (%SCOPE_HOST to %SCOPE_UNIVERSE) or -1 (%IADDR_INVALID) * for an invalid address. */ int ipa_classify(ip_addr x) { DUMMY } /** * ip4_class_mask - guess netmask according to address class * @x: IPv4 address * * This function (available in IPv4 version only) returns a * network mask according to the address class of @x. Although * classful addressing is nowadays obsolete, there still live * routing protocols transferring no prefix lengths nor netmasks * and this function could be useful to them. */ ip4_addr ip4_class_mask(ip4_addr x) { DUMMY } /** * ipa_from_u32 - convert IPv4 address to an integer * @x: IP address * * This function takes an IPv4 address and returns its numeric * representation. */ u32 ipa_from_u32(ip_addr x) { DUMMY } /** * ipa_to_u32 - convert integer to IPv4 address * @x: a 32-bit integer * * ipa_to_u32() takes a numeric representation of an IPv4 address * and converts it to the corresponding &ip_addr. */ ip_addr ipa_to_u32(u32 x) { DUMMY } /** * ipa_compare - compare two IP addresses for order * @x: IP address * @y: IP address * * The ipa_compare() function takes two IP addresses and returns * -1 if @x is less than @y in canonical ordering (lexicographical * order of the bit strings), 1 if @x is greater than @y and 0 * if they are the same. */ int ipa_compare(ip_addr x, ip_addr y) { DUMMY } /** * ipa_build6 - build an IPv6 address from parts * @a1: part #1 * @a2: part #2 * @a3: part #3 * @a4: part #4 * * ipa_build() takes @a1 to @a4 and assembles them to a single IPv6 * address. It's used for example when a protocol wants to bind its * socket to a hard-wired multicast address. */ ip_addr ipa_build6(u32 a1, u32 a2, u32 a3, u32 a4) { DUMMY } /** * ip_ntop - convert IP address to textual representation * @a: IP address * @buf: buffer of size at least %STD_ADDRESS_P_LENGTH * * This function takes an IP address and creates its textual * representation for presenting to the user. */ char *ip_ntop(ip_addr a, char *buf) { DUMMY } /** * ip_ntox - convert IP address to hexadecimal representation * @a: IP address * @buf: buffer of size at least %STD_ADDRESS_P_LENGTH * * This function takes an IP address and creates its hexadecimal * textual representation. Primary use: debugging dumps. */ char *ip_ntox(ip_addr a, char *buf) { DUMMY } /** * ip_pton - parse textual representation of IP address * @a: textual representation * @o: where to put the resulting address * * This function parses a textual IP address representation and * stores the decoded address to a variable pointed to by @o. * Returns 0 if a parse error has occurred, else 0. */ int ip_pton(char *a, ip_addr *o) { DUMMY } #endif