--- /dev/null
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (C) 2020 Marvell International Ltd.
+ */
+
+#ifndef __OTX2_IPSEC_ANTI_REPLAY_H__
+#define __OTX2_IPSEC_ANTI_REPLAY_H__
+
+#include <rte_mbuf.h>
+
+#include "otx2_ipsec_fp.h"
+
+#define WORD_SHIFT 6
+#define WORD_SIZE (1 << WORD_SHIFT)
+#define WORD_MASK (WORD_SIZE - 1)
+
+#define IPSEC_ANTI_REPLAY_FAILED (-1)
+
+static inline int
+anti_replay_check(uint64_t seq, struct otx2_ipsec_fp_in_sa *sa)
+{
+ struct otx2_ipsec_replay *replay = sa->replay;
+ uint64_t *window = &replay->window[0];
+ uint64_t winsz = sa->replay_win_sz;
+ uint64_t ex_winsz = winsz + WORD_SIZE;
+ uint64_t winwords = ex_winsz >> WORD_SHIFT;
+ uint64_t base = replay->base;
+ uint32_t winb = replay->winb;
+ uint32_t wint = replay->wint;
+ uint64_t seqword, shiftwords;
+ uint64_t bit_pos;
+ uint64_t shift;
+ uint64_t *wptr;
+ uint64_t tmp;
+
+ if (winsz > 64)
+ goto slow_shift;
+ /* Check if the seq is the biggest one yet */
+ if (likely(seq > base)) {
+ shift = seq - base;
+ if (shift < winsz) { /* In window */
+ /*
+ * If more than 64-bit anti-replay window,
+ * use slow shift routine
+ */
+ wptr = window + (shift >> WORD_SHIFT);
+ *wptr <<= shift;
+ *wptr |= 1ull;
+ } else {
+ /* No special handling of window size > 64 */
+ wptr = window + ((winsz - 1) >> WORD_SHIFT);
+ /*
+ * Zero out the whole window (especially for
+ * bigger than 64b window) till the last 64b word
+ * as the incoming sequence number minus
+ * base sequence is more than the window size.
+ */
+ while (window != wptr)
+ *window++ = 0ull;
+ /*
+ * Set the last bit (of the window) to 1
+ * as that corresponds to the base sequence number.
+ * Now any incoming sequence number which is
+ * (base - window size - 1) will pass anti-replay check
+ */
+ *wptr = 1ull;
+ }
+ /*
+ * Set the base to incoming sequence number as
+ * that is the biggest sequence number seen yet
+ */
+ replay->base = seq;
+ return 0;
+ }
+
+ bit_pos = base - seq;
+
+ /* If seq falls behind the window, return failure */
+ if (bit_pos >= winsz)
+ return IPSEC_ANTI_REPLAY_FAILED;
+
+ /* seq is within anti-replay window */
+ wptr = window + ((winsz - bit_pos - 1) >> WORD_SHIFT);
+ bit_pos &= WORD_MASK;
+
+ /* Check if this is a replayed packet */
+ if (*wptr & ((1ull) << bit_pos))
+ return IPSEC_ANTI_REPLAY_FAILED;
+
+ /* mark as seen */
+ *wptr |= ((1ull) << bit_pos);
+ return 0;
+
+slow_shift:
+ if (likely(seq > base)) {
+ uint32_t i;
+
+ shift = seq - base;
+ if (unlikely(shift >= winsz)) {
+ /*
+ * shift is bigger than the window,
+ * so just zero out everything
+ */
+ for (i = 0; i < winwords; i++)
+ window[i] = 0;
+winupdate:
+ /* Find out the word */
+ seqword = ((seq - 1) % ex_winsz) >> WORD_SHIFT;
+
+ /* Find out the bit in the word */
+ bit_pos = (seq - 1) & WORD_MASK;
+
+ /*
+ * Set the bit corresponding to sequence number
+ * in window to mark it as received
+ */
+ window[seqword] |= (1ull << (63 - bit_pos));
+
+ /* wint and winb range from 1 to ex_winsz */
+ replay->wint = ((wint + shift - 1) % ex_winsz) + 1;
+ replay->winb = ((winb + shift - 1) % ex_winsz) + 1;
+
+ replay->base = seq;
+ return 0;
+ }
+
+ /*
+ * New sequence number is bigger than the base but
+ * it's not bigger than base + window size
+ */
+
+ shiftwords = ((wint + shift - 1) >> WORD_SHIFT) -
+ ((wint - 1) >> WORD_SHIFT);
+ if (unlikely(shiftwords)) {
+ tmp = (wint + WORD_SIZE - 1) / WORD_SIZE;
+ for (i = 0; i < shiftwords; i++) {
+ tmp %= winwords;
+ window[tmp++] = 0;
+ }
+ }
+
+ goto winupdate;
+ }
+
+ /* Sequence number is before the window */
+ if (unlikely((seq + winsz) <= base))
+ return IPSEC_ANTI_REPLAY_FAILED;
+
+ /* Sequence number is within the window */
+
+ /* Find out the word */
+ seqword = ((seq - 1) % ex_winsz) >> WORD_SHIFT;
+
+ /* Find out the bit in the word */
+ bit_pos = (seq - 1) & WORD_MASK;
+
+ /* Check if this is a replayed packet */
+ if (window[seqword] & (1ull << (63 - bit_pos)))
+ return IPSEC_ANTI_REPLAY_FAILED;
+
+ /*
+ * Set the bit corresponding to sequence number
+ * in window to mark it as received
+ */
+ window[seqword] |= (1ull << (63 - bit_pos));
+
+ return 0;
+}
+
+static int
+cpt_ipsec_antireplay_check(struct otx2_ipsec_fp_in_sa *sa, char *data)
+{
+ uint64_t seq_in_sa;
+ uint32_t seqh = 0;
+ uint32_t seql;
+ uint64_t seq;
+ uint8_t esn;
+ int ret;
+
+ esn = sa->ctl.esn_en;
+ seql = rte_be_to_cpu_32(*((uint32_t *)(data +
+ OTX2_IPSEC_SEQNO_LO_INDEX)));
+
+ if (!esn)
+ seq = (uint64_t)seql;
+ else {
+ seqh = rte_be_to_cpu_32(*((uint32_t *)(data +
+ OTX2_IPSEC_SEQNO_HI_INDEX)));
+ seq = ((uint64_t)seqh << 32) | seql;
+ }
+
+ if (unlikely(seq == 0))
+ return IPSEC_ANTI_REPLAY_FAILED;
+
+ rte_spinlock_lock(&sa->replay->lock);
+ ret = anti_replay_check(seq, sa);
+ if (esn && (ret == 0)) {
+ seq_in_sa = ((uint64_t)rte_be_to_cpu_32(sa->esn_hi) << 32) |
+ rte_be_to_cpu_32(sa->esn_low);
+ if (seq > seq_in_sa) {
+ sa->esn_low = rte_cpu_to_be_32(seql);
+ sa->esn_hi = rte_cpu_to_be_32(seqh);
+ }
+ }
+ rte_spinlock_unlock(&sa->replay->lock);
+
+ return ret;
+}
+#endif /* __OTX2_IPSEC_ANTI_REPLAY_H__ */