---Problem Description---
userspace (setkey) is not able to add aes-ctr algorithm. aes-ctr definition
needs to be added to xfrm_nalgo.c. It is in xfrm_algo.c, but not in xfrm_nalgo.c 
 
---uname output---
2.6.18-88.el5
 
Machine Type = i386
 
---Steps to Reproduce---
 
The problem is on all platforms/architectures.

To reproduce, configure ipsec via setkey with,

spdflush;
flush;

add fc00:0:0:105::35 fc00:0:0:105::64 esp 35590
-m transport
-E aes-ctr "ipv6readylogaescin01"
-A aes-xcbc-mac "ipv6readaesxin01";

add fc00:0:0:105::64 fc00:0:0:105::35 esp 12360
-m transport
-E aes-ctr "ipv6readylogaescin01"
-A aes-xcbc-mac "ipv6readaesxin01";

spdadd ::/0 ::/0 icmp6 135,0 -P in none;
spdadd ::/0 ::/0 icmp6 135,0 -P out none;

spdadd -6 fc00:0:0:105::35 fc00:0:0:105::64 any
-P in ipsec
esp/transport//require;

spdadd -6 fc00:0:0:105::64 fc00:0:0:105::35 any
-P out ipsec
esp/transport//require;

setkey fails to add the SA since ipsec kernel doesn't recognize this algorithm.

I have tested a patch against RHEL5.2 snapshot 3 with the 88 kernel from dzickus and it appears to
work fine.

18 hour stress test completed successfully between i386 and ppc64.
Had aes-ctr and aes-xcbc-mac configured for ipsec via manual keying
between two machines sending tcp and udp packets of varying sizes.