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Diffstat (limited to 'src/ip6_bit.c')
| -rw-r--r-- | src/ip6_bit.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/src/ip6_bit.c b/src/ip6_bit.c new file mode 100644 index 0000000..528f0b0 --- /dev/null +++ b/src/ip6_bit.c @@ -0,0 +1,180 @@ +/** + @file ip6_bit.c + @author Li Minh Bui, feh + @funcs bytetohex, ip6_bitstring, bitstring_ip6, ip6_fmt_str +*/ +#include "ip.h" +#include "byte.h" +#include "str.h" +#include "fmt.h" +#include "stralloc.h" +#include "ip_bit.h" + +#define BITSUBSTITUTION + +/*** + /fn bytetohex + /brief Convert a number of max 255 to hex. + /param decimal The decimal number. + /param hex The converted hex value. +*/ + +void bytetohex(unsigned char decimal, char hex[3]) +{ + char* hexdigits = "0123456789ABCDEF"; + int rest, number; + hex[0] = '0'; + hex[1] = '0'; + hex[2] = '\0'; + + number = decimal / 16; + rest = decimal % 16; + + hex[0] = hexdigits[number]; + hex[1] = hexdigits[rest]; +} + +static char strnum[FMT_ULONG]; + +/*** + /fn ip6_bitstring + /brief This function converts a IPv6 address into its binary representation. + /param out: ip6string The destination address. + /param in: ip6addr The source address. + /param in: prefix The net prefix bits (maximum 128 bits for IPv6). + /return -1: lack of memory; 1: non valid IPv6 address; 0: successful converted. +*/ + +int ip6_bitstring(stralloc *ip6string, char *ip6addr, unsigned int prefix) +{ + char ip6[16]; + int bit, octettbitpos, number, shiftedvalue; + int i, slashpos, ip6len; + +#ifdef BITSUBSTITUTION + char subvalueforbitone[1]; + subvalueforbitone[0] = 96; /* substitution starts from token '_' = 96 */ +#endif + + ip6len = str_len(ip6addr); + slashpos = byte_chr(ip6addr,ip6len,'/'); + if (!stralloc_copyb(ip6string,ip6addr,slashpos)) return -1; + ip6addr[slashpos] = '\0'; + + if (!ip6_scan(ip6addr,ip6)) return 1; + if (!stralloc_copys(ip6string,"")) return -1; + + for (i = 0; i < 16; i++) { + number = (unsigned char) ip6[i]; + + for (octettbitpos = 7; octettbitpos >= 0; octettbitpos--) { + shiftedvalue = 1 << octettbitpos; + bit = number / shiftedvalue; + number = number - bit * (shiftedvalue); + + if (bit) { +#ifdef BITSUBSTITUTION + if (!stralloc_catb(ip6string,subvalueforbitone,1)) return -1; + subvalueforbitone[0]++; +#else + if (!stralloc_cats(ip6string,"1")) return -1; +#endif + } else + if (!stralloc_cats(ip6string,"0")) return -1; + + prefix--; + if (prefix == 0) return 0; + } + } + + return 1; +} + +/*** + /fn bitstring_ip6 + /brief This function converts a bit string which is produced by ip6_bitstring() + into an IPv6 address. The string may start with a '^'. + /param in: ip6string Source string which need to be converted. + /param out ip6addr 0-terminated IPv6 destination address with net prefix. + /return -1: No memory could allocated,0: Failure,1: Success. +*/ + +int bitstring_ip6(stralloc *ip6addr ,stralloc *ip6string) +{ + int j = 0; + int i = 0; + int len, prefix, shiftedvalue; + int bitpos = 7; + int decimalnumber = 0; + char ip6[16] = {0}; + char ip6compact[40] = {0}; + + if (!stralloc_copys(ip6addr,"")) return -1; + prefix = ip6string->len - 1; + + if (prefix <= 0) return 1; + if (prefix <= 1 || prefix > 128) return 1; + + if (ip6string->s[0] == '^') j = 1; + + for (i = j, j = 0; i <= prefix; i++) { + if (ip6string->s[i] != '0') { + shiftedvalue = 1 << bitpos; + decimalnumber += shiftedvalue; + } + bitpos--; + if (bitpos == -1) { /* Put each converted byte into the array. */ + if (j < 16) { + ip6[j] = (unsigned char) decimalnumber; + j++; + bitpos = 7; + decimalnumber = 0; + } + } + } + + if (bitpos < 7) { /* Last bit was read,but the number was not converted. */ + ip6[j] = (unsigned char) decimalnumber; + j++; + } + + len = ip6_fmt(ip6compact,ip6); + if (!len) return 1; + + if (!stralloc_copyb(ip6addr,ip6compact,len)) return -1; + if (!stralloc_cats(ip6addr,"/")) return -1; + if (!stralloc_catb(ip6addr,strnum,fmt_ulong(strnum,prefix))) return -1; + if (!stralloc_0(ip6addr)) return -1; + + return 0; +} +/*** + /fn ip6_fmt_str + /brief This function expands any valid IPv6 address into its full format of 16 bytes. + It returns the number of processed tokens on success. + /param src Source IPv6 address. + /param destination Expanded IPv6 address. + /return -1: No memory could allocated; 1: failure, 0: success +*/ + +unsigned int ip6_fmt_str(stralloc *dest, char *src) +{ + stralloc addr = {0}; + char ip6[16]; + char hexvalue[3] = {0, 0, 0}; + int i; + + if (!stralloc_copys(&addr,src)) return -1; + if (!stralloc_0(&addr)) return -1; + + if (ip6_scan(addr.s,ip6) == 0) return 1; + if (!stralloc_copys(dest,"")) return -1; + + for (i = 0; i < 16; i++) { + bytetohex((unsigned char)ip6[i],hexvalue); + stralloc_catb(dest,hexvalue,2); + if (!((i+1) % 2) && (i+1) < 16) + if (!stralloc_cats(dest,":")) return -1; /*Append ':' after every two bytes.*/ + } + return 0; +} |