/* * Copyright (c) 2016 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. */ #include <vnet/vnet.h> #include <vnet/mfib/mfib_signal.h> #include <vppinfra/dlist.h> /** * @brief Pool of signals */ static mfib_signal_t *mfib_signal_pool; /** * @brief pool of dlist elements */ static dlist_elt_t *mfib_signal_dlist_pool; /** * the list/set of interfaces with signals pending */ typedef struct mfib_signal_q_t_ { /** * the dlist indext that is the head of the list */ u32 mip_head; /** * Spin lock to protect the list */ int mip_lock; } mfib_signal_q_t; /** * @brief The pending queue of signals to deliver to the control plane */ static mfib_signal_q_t mfib_signal_pending ; static void mfib_signal_list_init (void) { dlist_elt_t *head; u32 hi; pool_get(mfib_signal_dlist_pool, head); hi = head - mfib_signal_dlist_pool; mfib_signal_pending.mip_head = hi; clib_dlist_init(mfib_signal_dlist_pool, hi); } void mfib_signal_module_init (void) { mfib_signal_list_init(); } static inline void mfib_signal_lock_aquire (void) { while (__sync_lock_test_and_set (&mfib_signal_pending.mip_lock, 1)) ; } static inline void mfib_signal_lock_release (void) { mfib_signal_pending.mip_lock = 0; } #define MFIB_SIGNAL_CRITICAL_SECTION(_body) \ { \ mfib_signal_lock_aquire(); \ do { \ _body; \ } while (0); \ mfib_signal_lock_release(); \ } int mfib_signal_send_one (struct _unix_shared_memory_queue *q, u32 context) { u32 li, si; /* * with the lock held, pop a signal from the q. */ MFIB_SIGNAL_CRITICAL_SECTION( ({ li = clib_dlist_remove_head(mfib_signal_dlist_pool, mfib_signal_pending.mip_head); })); if (~0 != li) { mfib_signal_t *mfs; mfib_itf_t *mfi; dlist_elt_t *elt; elt = pool_elt_at_index(mfib_signal_dlist_pool, li); si = elt->value; mfs = pool_elt_at_index(mfib_signal_pool, si); mfi = mfib_itf_get(mfs->mfs_itf); mfi->mfi_si = INDEX_INVALID; __sync_fetch_and_and(&mfi->mfi_flags, ~MFIB_ITF_FLAG_SIGNAL_PRESENT); vl_mfib_signal_send_one(q, context, mfs); /* * with the lock held, return the resoruces of the signals posted */ MFIB_SIGNAL_CRITICAL_SECTION( ({ pool_put_index(mfib_signal_pool, si); pool_put_index(mfib_signal_dlist_pool, li); })); return (1); } return (0); } void mfib_signal_push (const mfib_entry_t *mfe, mfib_itf_t *mfi, vlib_buffer_t *b0) { mfib_signal_t *mfs; dlist_elt_t *elt; u32 si, li; MFIB_SIGNAL_CRITICAL_SECTION( ({ pool_get(mfib_signal_pool, mfs); pool_get(mfib_signal_dlist_pool, elt); si = mfs - mfib_signal_pool; li = elt - mfib_signal_dlist_pool; elt->value = si; mfi->mfi_si = li; clib_dlist_addhead(mfib_signal_dlist_pool, mfib_signal_pending.mip_head, li); })); mfs->mfs_entry = mfib_entry_get_index(mfe); mfs->mfs_itf = mfib_itf_get_index(mfi); if (NULL != b0) { mfs->mfs_buffer_len = b0->current_length; memcpy(mfs->mfs_buffer, vlib_buffer_get_current(b0), (mfs->mfs_buffer_len > MFIB_SIGNAL_BUFFER_SIZE ? MFIB_SIGNAL_BUFFER_SIZE : mfs->mfs_buffer_len)); } else { mfs->mfs_buffer_len = 0; } } void mfib_signal_remove_itf (const mfib_itf_t *mfi) { u32 li; /* * lock the queue to prevent further additions while we fiddle. */ li = mfi->mfi_si; if (INDEX_INVALID != li) { /* * it's in the pending q */ MFIB_SIGNAL_CRITICAL_SECTION( ({ dlist_elt_t *elt; /* * with the lock held; * - remove the signal from the pending list * - free up the signal and list entry obejcts */ clib_dlist_remove(mfib_signal_dlist_pool, li); elt = pool_elt_at_index(mfib_signal_dlist_pool, li); pool_put_index(mfib_signal_pool, elt->value); pool_put(mfib_signal_dlist_pool, elt); })); } }