diff options
Diffstat (limited to 'src/plugins/nat/nat_det.h')
| -rw-r--r-- | src/plugins/nat/nat_det.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/src/plugins/nat/nat_det.h b/src/plugins/nat/nat_det.h new file mode 100644 index 00000000000..2ab7f27eece --- /dev/null +++ b/src/plugins/nat/nat_det.h @@ -0,0 +1,196 @@ +/* + * snat_det.h - deterministic NAT definitions + * + * Copyright (c) 2017 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +/** + * @file + * @brief deterministic NAT definitions + */ + +#ifndef __included_nat_det_h__ +#define __included_nat_det_h__ + +#include <vnet/ip/ip.h> +#include <nat/nat.h> +#include <nat/nat_ipfix_logging.h> + + +#define SNAT_DET_SES_PER_USER 1000 + + +int snat_det_add_map (snat_main_t * sm, ip4_address_t * in_addr, u8 in_plen, + ip4_address_t * out_addr, u8 out_plen, int is_add); + +always_inline int +is_addr_in_net (ip4_address_t * addr, ip4_address_t * net, u8 plen) +{ + if (net->as_u32 == (addr->as_u32 & ip4_main.fib_masks[plen])) + return 1; + return 0; +} + +always_inline snat_det_map_t * +snat_det_map_by_user (snat_main_t * sm, ip4_address_t * user_addr) +{ + snat_det_map_t *dm; + + /* *INDENT-OFF* */ + pool_foreach (dm, sm->det_maps, + ({ + if (is_addr_in_net(user_addr, &dm->in_addr, dm->in_plen)) + return dm; + })); + /* *INDENT-ON* */ + return 0; +} + +always_inline snat_det_map_t * +snat_det_map_by_out (snat_main_t * sm, ip4_address_t * out_addr) +{ + snat_det_map_t *dm; + + /* *INDENT-OFF* */ + pool_foreach (dm, sm->det_maps, + ({ + if (is_addr_in_net(out_addr, &dm->out_addr, dm->out_plen)) + return dm; + })); + /* *INDENT-ON* */ + return 0; +} + +always_inline void +snat_det_forward (snat_det_map_t * dm, ip4_address_t * in_addr, + ip4_address_t * out_addr, u16 * lo_port) +{ + u32 in_offset, out_offset; + + in_offset = clib_net_to_host_u32 (in_addr->as_u32) - + clib_net_to_host_u32 (dm->in_addr.as_u32); + out_offset = in_offset / dm->sharing_ratio; + out_addr->as_u32 = + clib_host_to_net_u32 (clib_net_to_host_u32 (dm->out_addr.as_u32) + + out_offset); + *lo_port = 1024 + dm->ports_per_host * (in_offset % dm->sharing_ratio); +} + +always_inline void +snat_det_reverse (snat_det_map_t * dm, ip4_address_t * out_addr, u16 out_port, + ip4_address_t * in_addr) +{ + u32 in_offset1, in_offset2, out_offset; + + out_offset = clib_net_to_host_u32 (out_addr->as_u32) - + clib_net_to_host_u32 (dm->out_addr.as_u32); + in_offset1 = out_offset * dm->sharing_ratio; + in_offset2 = (out_port - 1024) / dm->ports_per_host; + in_addr->as_u32 = + clib_host_to_net_u32 (clib_net_to_host_u32 (dm->in_addr.as_u32) + + in_offset1 + in_offset2); +} + +always_inline u32 +snat_det_user_ses_offset (ip4_address_t * addr, u8 plen) +{ + return (clib_net_to_host_u32 (addr->as_u32) & pow2_mask (32 - plen)) * + SNAT_DET_SES_PER_USER; +} + +always_inline snat_det_session_t * +snat_det_get_ses_by_out (snat_det_map_t * dm, ip4_address_t * in_addr, + u64 out_key) +{ + u32 user_offset; + u16 i; + + user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen); + for (i = 0; i < SNAT_DET_SES_PER_USER; i++) + { + if (dm->sessions[i + user_offset].out.as_u64 == out_key) + return &dm->sessions[i + user_offset]; + } + + return 0; +} + +always_inline snat_det_session_t * +snat_det_find_ses_by_in (snat_det_map_t * dm, ip4_address_t * in_addr, + u16 in_port, snat_det_out_key_t out_key) +{ + snat_det_session_t *ses; + u32 user_offset; + u16 i; + + user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen); + for (i = 0; i < SNAT_DET_SES_PER_USER; i++) + { + ses = &dm->sessions[i + user_offset]; + if (ses->in_port == in_port && + ses->out.ext_host_addr.as_u32 == out_key.ext_host_addr.as_u32 && + ses->out.ext_host_port == out_key.ext_host_port) + return &dm->sessions[i + user_offset]; + } + + return 0; +} + +always_inline snat_det_session_t * +snat_det_ses_create (snat_det_map_t * dm, ip4_address_t * in_addr, + u16 in_port, snat_det_out_key_t * out) +{ + u32 user_offset; + u16 i; + + user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen); + + for (i = 0; i < SNAT_DET_SES_PER_USER; i++) + { + if (!dm->sessions[i + user_offset].in_port) + { + if (__sync_bool_compare_and_swap + (&dm->sessions[i + user_offset].in_port, 0, in_port)) + { + dm->sessions[i + user_offset].out.as_u64 = out->as_u64; + dm->sessions[i + user_offset].state = SNAT_SESSION_UNKNOWN; + dm->sessions[i + user_offset].expire = 0; + __sync_add_and_fetch (&dm->ses_num, 1); + return &dm->sessions[i + user_offset]; + } + } + } + + snat_ipfix_logging_max_entries_per_user (in_addr->as_u32); + return 0; +} + +always_inline void +snat_det_ses_close (snat_det_map_t * dm, snat_det_session_t * ses) +{ + if (__sync_bool_compare_and_swap (&ses->in_port, ses->in_port, 0)) + { + ses->out.as_u64 = 0; + __sync_add_and_fetch (&dm->ses_num, -1); + } +} + +#endif /* __included_nat_det_h__ */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |