diff options
Diffstat (limited to 'src/dnsstub/dns_sortip.c')
-rw-r--r-- | src/dnsstub/dns_sortip.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/dnsstub/dns_sortip.c b/src/dnsstub/dns_sortip.c new file mode 100644 index 0000000..56742e0 --- /dev/null +++ b/src/dnsstub/dns_sortip.c @@ -0,0 +1,45 @@ +#include "byte.h" +#include "ip.h" +#include "dnsresolv.h" + +/** + @file dns_sortip.c + @authors djb, fefe, feh + @source ucspi-tcp6 + @brief random sort of DNS servers per IP +*/ + +/* XXX: sort servers by configurable notion of closeness? */ +/* XXX: pay attention to competence of each server? */ +/* XXX: pay attention to qualification (DNSSec, DNSCurve) of each server? */ +/* YYY: we use a randomly sorted list of NS; not depending on answer */ + +void dns_sortip4(char *s,unsigned int n) +{ + unsigned int i; + char tmp[4]; + + n >>= 2; /* 4 byte per IPv4 address */ + while (n > 1) { + i = dns_random(n); + --n; + byte_copy(tmp,4,s + (i << 2)); + byte_copy(s + (i << 2),4,s + (n << 2)); + byte_copy(s + (n << 2),4,tmp); + } +} + +void dns_sortip6(char *s,unsigned int n) +{ + unsigned int i; + char tmp[16]; + + n >>= 4; /* 16 byte per IPv4 address */ + while (n > 1) { + i = dns_random(n); + --n; + byte_copy(tmp,16,s + (i << 4)); + byte_copy(s + (i << 4),16,s + (n << 4)); + byte_copy(s + (n << 4),16,tmp); + } +} |