Ordering IP addresses [Non trivial]
Your atention, please...
At ACLIP.cc there is a function setting up a order relationship given two
IP addresses/networks...
aclIPaddrNetworkCompare()
struct IN_ADDR A = p-addr1;
const struct IN_ADDR B = q-addr1;
const struct IN_ADDR C = q-addr2;
A.s_addr = q-mask.s_addr; /* apply netmask */
if (C.s_addr == 0) {/* single address check */
if (ntohl(A.s_addr) ntohl(B.s_addr))
return 1;
else if (ntohl(A.s_addr) ntohl(B.s_addr))
return -1;
else
return 0;
} else {/* range address check */
if (ntohl(A.s_addr) ntohl(C.s_addr))
return 1;
else if (ntohl(A.s_addr) ntohl(B.s_addr))
return -1;
else
return 0;
}
Bassically they mask the first address, and after that they reuse the
underlying 32 bits integers, referring to integer order relation ship...
NOTES:
--
- Solved the masking on IPv6, I cannot compare 128 bits integers, unless
I define it. (squid128_int_t)
- I can redefine the address ordering to byte-to-byte comparing (memcmp)
on the two memory areas A B , but on IPv4 and i386 boxes§ they would
invert the actual order, since network order inverts the bytes on host order
(ntohl) , so...
- The rest of calling software will not be ready to support this new
ordering (-1,0,1) -- (1,0,-1) Would be very difficult to change it into
this new order ?
- If not answer available in a short time, given the close date to
benchmarking IPv6, were can I order Squid to bypass all the ACLIP
constraints
on squid.conf ?
--
PGP public key: http://www.ngn.euro6ix.org/IPv6/rafael.martinez.gpg
Re: Ordering IP addresses [Non trivial]
- I can redefine the address ordering to byte-to-byte comparing (memcmp) on the two memory areas A B , but on IPv4 and i386 boxes§ they would invert the actual order, since network order inverts the bytes on host order (ntohl) , so... OK. As I see, the only purpose of previous function was to provide a function to short the nodes of balanced tree SplayV ... No other semantics beyond that is intended... typedef Splayacl_ip_data * IPsplay ; - The rest of calling software will not be ready to support this new ordering (-1,0,1) -- (1,0,-1) Would be very difficult to change it into this new order ? Changed the order relationship, the logics for the abstract balanced tree is kept... So, it is not dangerous to redefine the relation in terms of memcmp(...) Cleaner, even. - If not answer available in a short time, given the close date to benchmarking IPv6, were can I order Squid to bypass all the ACLIP constraints on squid.conf ? Brrr It's my second obsessed mistake in terms of IPv6'fied 128 bits numbers... ASN has to do just rigth with BGP4+ , and aclIPAddrNetworkCompare is just a order relationship for the nodes of an abstract balanced tree... Things are easier than thought... I should interpret the meaning of variables, not just is type -- PGP public key: http://www.ngn.euro6ix.org/IPv6/rafael.martinez.gpg
Re: [Squid-cvs] squid3-ipv6 squid3/src ACLIP.cc,1.8.2.4,1.8.2.5
On Wed, 25 May 2005, Rafael Martinez Torres wrote: Index: ACLIP.cc -if (ntohl(A.s_addr) ntohl(C.s_addr)) +if (memcmp(A, C, sizeof(struct IN_ADDR)) 0) Hmm.. this has quite different semantics. The original looks at the addresses in host byte order, while the memcmp looks at the addresses in network byte order... are you sure this change is OK here? Regards Henrik
Re: Ordering IP addresses [Non trivial]
On Wed, 25 May 2005, Rafael Martinez Torres wrote: NOTES: -- - Solved the masking on IPv6, I cannot compare 128 bits integers, unless I define it. (squid128_int_t) - I can redefine the address ordering to byte-to-byte comparing (memcmp) on the two memory areas A B , but on IPv4 and i386 boxes§ they would invert the actual order, since network order inverts the bytes on host order (ntohl) , so... - The rest of calling software will not be ready to support this new ordering (-1,0,1) -- (1,0,-1) Would be very difficult to change it into this new order ? Either should be fine, as long as you are consistent, but if this is the only problem then all you need is to return the negated result. Thinking.. memcmp() will actually compare correctly. memcmp() is the same as comparing ntohl values as integers thanks to network byte order being most significant octet first. So the second point above (and my separate comment) is a non-issue. - If not answer available in a short time, given the close date to benchmarking IPv6, were can I order Squid to bypass all the ACLIP constraints on squid.conf ? It's all there in ACLIP.cc. acl_ip_data::NetworkCompare() but I fail to see why this would be an issue. Regards Henrik
Re: [Squid-cvs] squid3-ipv6 squid3/src ACLIP.cc,1.8.2.4,1.8.2.5
On Thu, 26 May 2005, Henrik Nordstrom wrote: On Wed, 25 May 2005, Rafael Martinez Torres wrote: Index: ACLIP.cc -if (ntohl(A.s_addr) ntohl(C.s_addr)) +if (memcmp(A, C, sizeof(struct IN_ADDR)) 0) Hmm.. this has quite different semantics. The original looks at the addresses in host byte order, while the memcmp looks at the addresses in network byte order... Err.. both methods looks at the addresses in the correct order. It's just my brain trying to compose emails while asleep. Regards Henrik
