/* * Copyright (c) 2020 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. */ /** * @brief FIB Source Address selection * * Use the FIB for source address selection on an interface */ #include <vnet/fib/fib_sas.h> #include <vnet/adj/adj_glean.h> #include <vnet/ip/ip6_link.h> bool fib_sas_get (u32 sw_if_index, ip_address_family_t af, const ip46_address_t *dst, ip46_address_t *src) { switch (af) { case AF_IP4: if (dst) return (fib_sas4_get(sw_if_index, &dst->ip4, &src->ip4)); else return (fib_sas4_get(sw_if_index, NULL, &src->ip4)); case AF_IP6: if (dst) return (fib_sas6_get(sw_if_index, &dst->ip6, &src->ip6)); else return (fib_sas6_get(sw_if_index, NULL, &src->ip6)); } return (false); } bool fib_sas4_get (u32 sw_if_index, const ip4_address_t *dst, ip4_address_t *src) { ip46_address_t d_tmp, *d_tmpp = NULL; const ip46_address_t *s_tmp; vnet_sw_interface_t *swif; if (dst) { d_tmpp = &d_tmp; d_tmp.ip4 = *dst; } if (vnet_sw_interface_is_p2p(vnet_get_main(), sw_if_index)) { ip4_address_t *ip4; ip4 = ip_interface_get_first_ip (sw_if_index, 1); if (ip4) { src->as_u32 = ip4->as_u32; return (true); } else { return (false); } } /* * If the interface is unnumbered then use the IP interface */ swif = vnet_get_sw_interface (vnet_get_main(), sw_if_index); if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) sw_if_index = swif->unnumbered_sw_if_index; /* * get the source address from the glean adjacency */ s_tmp = adj_glean_get_src (FIB_PROTOCOL_IP4, sw_if_index, d_tmpp); if (NULL != s_tmp) { src->as_u32 = s_tmp->ip4.as_u32; return (true); } return (false); } bool fib_sas6_get (u32 sw_if_index, const ip6_address_t *dst, ip6_address_t *src) { ip46_address_t d_tmp, *d_tmpp = NULL; const ip46_address_t *s_tmp; if (dst) { d_tmpp = &d_tmp; d_tmp.ip6 = *dst; } /* * if the dst is v6 and link local, use the source link local */ if (ip6_address_is_link_local_unicast (dst)) { const ip6_address_t *ll = ip6_get_link_local_address (sw_if_index); if (NULL == ll) { return (false); } ip6_address_copy (src, ll); return (true); } if (vnet_sw_interface_is_p2p(vnet_get_main(), sw_if_index)) { ip6_address_t *ip6; ip6 = ip_interface_get_first_ip (sw_if_index, 0); if (ip6) { ip6_address_copy(src, ip6); return (true); } else { return (false); } } /* * get the source address from the glean adjacency */ s_tmp = adj_glean_get_src (FIB_PROTOCOL_IP6, sw_if_index, d_tmpp); if (NULL != s_tmp) { ip6_address_copy(src, &s_tmp->ip6); return (true); } return (false); }