[dpdk-dev] [PATCH 06/10] ipsec: add transmit segmentation offload support

[Radu Nicolau <radu.nicolau@intel.com>]

Add support for transmit segmentation offload to inline crypto processing
mode. This offload is not supported by other offload modes, as at a
minimum it requires inline crypto for IPsec to be supported on the
network interface.

Signed-off-by: Declan Doherty <declan.doherty@intel.com>
Signed-off-by: Radu Nicolau <radu.nicolau@intel.com>
Signed-off-by: Abhijit Sinha <abhijit.sinha@intel.com>
Signed-off-by: Daniel Martin Buckley <daniel.m.buckley@intel.com>
---
 lib/ipsec/esp_inb.c  |   4 +-
 lib/ipsec/esp_outb.c | 115 +++++++++++++++++++++++++++++++++++--------
 lib/ipsec/iph.h      |  10 +++-
 lib/ipsec/sa.c       |   6 +++
 lib/ipsec/sa.h       |   4 ++
 5 files changed, 114 insertions(+), 25 deletions(-)

diff --git a/lib/ipsec/esp_inb.c b/lib/ipsec/esp_inb.c
index d66c88f05d..a6ab8fbdd5 100644
--- a/lib/ipsec/esp_inb.c
+++ b/lib/ipsec/esp_inb.c
@@ -668,8 +668,8 @@ trs_process(const struct rte_ipsec_sa *sa, struct rte_mbuf *mb[],
 			/* modify packet's layout */
 			np = trs_process_step2(mb[i], ml[i], hl[i], cofs,
 				to[i], tl, sqn + k);
-			update_trs_l3hdr(sa, np + l2, mb[i]->pkt_len,
-				l2, hl[i] - l2, espt[i].next_proto);
+			update_trs_l34hdrs(sa, np + l2, mb[i]->pkt_len,
+				l2, hl[i] - l2, espt[i].next_proto, 0);
 
 			/* update mbuf's metadata */
 			trs_process_step3(mb[i]);
diff --git a/lib/ipsec/esp_outb.c b/lib/ipsec/esp_outb.c
index a3f77469c3..9fc7075796 100644
--- a/lib/ipsec/esp_outb.c
+++ b/lib/ipsec/esp_outb.c
@@ -2,6 +2,8 @@
  * Copyright(c) 2018-2020 Intel Corporation
  */
 
+#include <math.h>
+
 #include <rte_ipsec.h>
 #include <rte_esp.h>
 #include <rte_ip.h>
@@ -156,11 +158,20 @@ outb_tun_pkt_prepare(struct rte_ipsec_sa *sa, rte_be64_t sqc,
 
 	/* number of bytes to encrypt */
 	clen = plen + sizeof(*espt);
-	clen = RTE_ALIGN_CEIL(clen, sa->pad_align);
+
+	/* We don't need to pad/ailgn packet when using TSO offload */
+	if (likely(!(mb->ol_flags & (PKT_TX_TCP_SEG | PKT_TX_UDP_SEG))))
+		clen = RTE_ALIGN_CEIL(clen, sa->pad_align);
+
 
 	/* pad length + esp tail */
 	pdlen = clen - plen;
-	tlen = pdlen + sa->icv_len + sqh_len;
+
+	/* We don't append ICV length when using TSO offload */
+	if (likely(!(mb->ol_flags & (PKT_TX_TCP_SEG | PKT_TX_UDP_SEG))))
+		tlen = pdlen + sa->icv_len + sqh_len;
+	else
+		tlen = pdlen + sqh_len;
 
 	/* do append and prepend */
 	ml = rte_pktmbuf_lastseg(mb);
@@ -337,6 +348,7 @@ outb_trs_pkt_prepare(struct rte_ipsec_sa *sa, rte_be64_t sqc,
 	char *ph, *pt;
 	uint64_t *iv;
 	uint32_t l2len, l3len;
+	uint8_t tso = mb->ol_flags & (PKT_TX_TCP_SEG | PKT_TX_UDP_SEG) ? 1 : 0;
 
 	l2len = mb->l2_len;
 	l3len = mb->l3_len;
@@ -349,11 +361,19 @@ outb_trs_pkt_prepare(struct rte_ipsec_sa *sa, rte_be64_t sqc,
 
 	/* number of bytes to encrypt */
 	clen = plen + sizeof(*espt);
-	clen = RTE_ALIGN_CEIL(clen, sa->pad_align);
+
+	/* We don't need to pad/ailgn packet when using TSO offload */
+	if (likely(!tso))
+		clen = RTE_ALIGN_CEIL(clen, sa->pad_align);
 
 	/* pad length + esp tail */
 	pdlen = clen - plen;
-	tlen = pdlen + sa->icv_len + sqh_len;
+
+	/* We don't append ICV length when using TSO offload */
+	if (likely(!tso))
+		tlen = pdlen + sa->icv_len + sqh_len;
+	else
+		tlen = pdlen + sqh_len;
 
 	/* do append and insert */
 	ml = rte_pktmbuf_lastseg(mb);
@@ -375,8 +395,8 @@ outb_trs_pkt_prepare(struct rte_ipsec_sa *sa, rte_be64_t sqc,
 	insert_esph(ph, ph + hlen, uhlen);
 
 	/* update ip  header fields */
-	np = update_trs_l3hdr(sa, ph + l2len, mb->pkt_len - sqh_len, l2len,
-			l3len, IPPROTO_ESP);
+	np = update_trs_l34hdrs(sa, ph + l2len, mb->pkt_len - sqh_len, l2len,
+			l3len, IPPROTO_ESP, tso);
 
 	/* update spi, seqn and iv */
 	esph = (struct rte_esp_hdr *)(ph + uhlen);
@@ -651,6 +671,33 @@ inline_outb_mbuf_prepare(const struct rte_ipsec_session *ss,
 	}
 }
 
+/* check if packet will exceed MSS and segmentation is required */
+static inline int
+esn_outb_nb_segments(const struct rte_ipsec_sa *sa, struct rte_mbuf *m) {
+	uint16_t segments = 1;
+	uint16_t pkt_l3len = m->pkt_len - m->l2_len;
+
+	/* Only support segmentation for UDP/TCP flows */
+	if (!(m->packet_type & (RTE_PTYPE_L4_UDP | RTE_PTYPE_L4_TCP)))
+		return segments;
+
+	if (sa->tso.enabled && pkt_l3len > sa->tso.mss) {
+		segments = ceil((float)pkt_l3len / sa->tso.mss);
+
+		if  (m->packet_type & RTE_PTYPE_L4_TCP) {
+			m->ol_flags |= (PKT_TX_TCP_SEG | PKT_TX_TCP_CKSUM);
+			m->l4_len = sizeof(struct rte_tcp_hdr);
+		} else {
+			m->ol_flags |= (PKT_TX_UDP_SEG | PKT_TX_UDP_CKSUM);
+			m->l4_len = sizeof(struct rte_udp_hdr);
+		}
+
+		m->tso_segsz = sa->tso.mss;
+	}
+
+	return segments;
+}
+
 /*
  * process group of ESP outbound tunnel packets destined for
  * INLINE_CRYPTO type of device.
@@ -660,24 +707,29 @@ inline_outb_tun_pkt_process(const struct rte_ipsec_session *ss,
 	struct rte_mbuf *mb[], uint16_t num)
 {
 	int32_t rc;
-	uint32_t i, k, n;
+	uint32_t i, k, nb_sqn = 0, nb_sqn_alloc;
 	uint64_t sqn;
 	rte_be64_t sqc;
 	struct rte_ipsec_sa *sa;
 	union sym_op_data icv;
 	uint64_t iv[IPSEC_MAX_IV_QWORD];
 	uint32_t dr[num];
+	uint16_t nb_segs[num];
 
 	sa = ss->sa;
 
-	n = num;
-	sqn = esn_outb_update_sqn(sa, &n);
-	if (n != num)
+	for (i = 0; i != num; i++) {
+		nb_segs[i] = esn_outb_nb_segments(sa, mb[i]);
+		nb_sqn += nb_segs[i];
+	}
+
+	nb_sqn_alloc = nb_sqn;
+	sqn = esn_outb_update_sqn(sa, &nb_sqn_alloc);
+	if (nb_sqn_alloc != nb_sqn)
 		rte_errno = EOVERFLOW;
 
 	k = 0;
-	for (i = 0; i != n; i++) {
-
+	for (i = 0; i != num; i++) {
 		sqc = rte_cpu_to_be_64(sqn + i);
 		gen_iv(iv, sqc);
 
@@ -691,11 +743,18 @@ inline_outb_tun_pkt_process(const struct rte_ipsec_session *ss,
 			dr[i - k] = i;
 			rte_errno = -rc;
 		}
+
+		/**
+		 * If packet is using tso, increment sqn by the number of
+		 * segments for	packet
+		 */
+		if  (mb[i]->ol_flags & (PKT_TX_TCP_SEG | PKT_TX_UDP_SEG))
+			sqn += nb_segs[i] - 1;
 	}
 
 	/* copy not processed mbufs beyond good ones */
-	if (k != n && k != 0)
-		move_bad_mbufs(mb, dr, n, n - k);
+	if (k != num && k != 0)
+		move_bad_mbufs(mb, dr, num, num - k);
 
 	inline_outb_mbuf_prepare(ss, mb, k);
 	return k;
@@ -710,23 +769,30 @@ inline_outb_trs_pkt_process(const struct rte_ipsec_session *ss,
 	struct rte_mbuf *mb[], uint16_t num)
 {
 	int32_t rc;
-	uint32_t i, k, n;
+	uint32_t i, k, nb_sqn, nb_sqn_alloc;
 	uint64_t sqn;
 	rte_be64_t sqc;
 	struct rte_ipsec_sa *sa;
 	union sym_op_data icv;
 	uint64_t iv[IPSEC_MAX_IV_QWORD];
 	uint32_t dr[num];
+	uint16_t nb_segs[num];
 
 	sa = ss->sa;
 
-	n = num;
-	sqn = esn_outb_update_sqn(sa, &n);
-	if (n != num)
+	/* Calculate number of sequence numbers required */
+	for (i = 0, nb_sqn = 0; i != num; i++) {
+		nb_segs[i] = esn_outb_nb_segments(sa, mb[i]);
+		nb_sqn += nb_segs[i];
+	}
+
+	nb_sqn_alloc = nb_sqn;
+	sqn = esn_outb_update_sqn(sa, &nb_sqn_alloc);
+	if (nb_sqn_alloc != nb_sqn)
 		rte_errno = EOVERFLOW;
 
 	k = 0;
-	for (i = 0; i != n; i++) {
+	for (i = 0; i != num; i++) {
 
 		sqc = rte_cpu_to_be_64(sqn + i);
 		gen_iv(iv, sqc);
@@ -741,11 +807,18 @@ inline_outb_trs_pkt_process(const struct rte_ipsec_session *ss,
 			dr[i - k] = i;
 			rte_errno = -rc;
 		}
+
+		/**
+		 * If packet is using tso, increment sqn by the number of
+		 * segments for	packet
+		 */
+		if  (mb[i]->ol_flags & (PKT_TX_TCP_SEG | PKT_TX_UDP_SEG))
+			sqn += nb_segs[i] - 1;
 	}
 
 	/* copy not processed mbufs beyond good ones */
-	if (k != n && k != 0)
-		move_bad_mbufs(mb, dr, n, n - k);
+	if (k != num && k != 0)
+		move_bad_mbufs(mb, dr, num, num - k);
 
 	inline_outb_mbuf_prepare(ss, mb, k);
 	return k;
diff --git a/lib/ipsec/iph.h b/lib/ipsec/iph.h
index 861f16905a..2d223199ac 100644
--- a/lib/ipsec/iph.h
+++ b/lib/ipsec/iph.h
@@ -6,6 +6,8 @@
 #define _IPH_H_
 
 #include <rte_ip.h>
+#include <rte_udp.h>
+#include <rte_tcp.h>
 
 /**
  * @file iph.h
@@ -39,8 +41,8 @@ insert_esph(char *np, char *op, uint32_t hlen)
 
 /* update original ip header fields for transport case */
 static inline int
-update_trs_l3hdr(const struct rte_ipsec_sa *sa, void *p, uint32_t plen,
-		uint32_t l2len, uint32_t l3len, uint8_t proto)
+update_trs_l34hdrs(const struct rte_ipsec_sa *sa, void *p, uint32_t plen,
+		uint32_t l2len, uint32_t l3len, uint8_t proto, uint8_t tso)
 {
 	int32_t rc;
 
@@ -51,6 +53,10 @@ update_trs_l3hdr(const struct rte_ipsec_sa *sa, void *p, uint32_t plen,
 		v4h = p;
 		rc = v4h->next_proto_id;
 		v4h->next_proto_id = proto;
+		if (tso) {
+			v4h->hdr_checksum = 0;
+			v4h->total_length = 0;
+		}
 		v4h->total_length = rte_cpu_to_be_16(plen - l2len);
 	/* IPv6 */
 	} else {
diff --git a/lib/ipsec/sa.c b/lib/ipsec/sa.c
index 720e0f365b..2ecbbce0a4 100644
--- a/lib/ipsec/sa.c
+++ b/lib/ipsec/sa.c
@@ -565,6 +565,12 @@ rte_ipsec_sa_init(struct rte_ipsec_sa *sa, const struct rte_ipsec_sa_prm *prm,
 	sa->type = type;
 	sa->size = sz;
 
+
+	if (prm->ipsec_xform.options.tso == 1) {
+		sa->tso.enabled = 1;
+		sa->tso.mss = prm->ipsec_xform.mss;
+	}
+
 	/* check for ESN flag */
 	sa->sqn_mask = (prm->ipsec_xform.options.esn == 0) ?
 		UINT32_MAX : UINT64_MAX;
diff --git a/lib/ipsec/sa.h b/lib/ipsec/sa.h
index 107ebd1519..5e237f3525 100644
--- a/lib/ipsec/sa.h
+++ b/lib/ipsec/sa.h
@@ -113,6 +113,10 @@ struct rte_ipsec_sa {
 	uint8_t iv_len;
 	uint8_t pad_align;
 	uint8_t tos_mask;
+	struct {
+		uint8_t enabled:1;
+		uint16_t mss;
+	} tso;
 
 	/* template for tunnel header */
 	uint8_t hdr[IPSEC_MAX_HDR_SIZE];
-- 
2.25.1