RE: [PATCH v2] ipsec: allow stateless IPsec processing

[Aakash Sasidharan <asasidharan@marvell.com>]

> > Introduce stateless packet preparation API for IPsec processing. The
> > new API would allow preparation of IPsec packets without altering the
> > internal state of an IPsec session.
> >
> > For outbound IPsec processing, the change enables user to provide
> > sequence number to be used for the IPsec operation.
> 
> Few questions/nits below.
> As a generic one - we need to add a use-case/test-case for it.
> Without it I think the patch is incomplete.

Ack. Will add test-case with v3.

> 
> >
> > Signed-off-by: Aakash Sasidharan <asasidharan@marvell.com>
> > ---
> >  lib/ipsec/esp_outb.c  | 85
> > +++++++++++++++++++++++++++++++------------
> >  lib/ipsec/rte_ipsec.h | 68 ++++++++++++++++++++++++++++++++++
> >  lib/ipsec/sa.c        |  4 +-
> >  lib/ipsec/sa.h        |  8 ++++
> >  4 files changed, 140 insertions(+), 25 deletions(-)
> >
> > diff --git a/lib/ipsec/esp_outb.c b/lib/ipsec/esp_outb.c index
> > ec87b1dce2..de28cb166d 100644
> > --- a/lib/ipsec/esp_outb.c
> > +++ b/lib/ipsec/esp_outb.c
> > @@ -288,13 +288,12 @@ outb_pkt_xprepare(const struct rte_ipsec_sa *sa,
> > rte_be64_t sqc,
> >  /*
> >   * setup/update packets and crypto ops for ESP outbound tunnel case.
> >   */
> > -uint16_t
> > -esp_outb_tun_prepare(const struct rte_ipsec_session *ss, struct rte_mbuf
> *mb[],
> > -	struct rte_crypto_op *cop[], uint16_t num)
> > +static inline uint16_t
> > +esp_outb_tun_prepare_helper(const struct rte_ipsec_session *ss, struct
> rte_mbuf *mb[],
> > +	struct rte_crypto_op *cop[], uint16_t num, uint64_t sqn)
> >  {
> >  	int32_t rc;
> > -	uint32_t i, k, n;
> > -	uint64_t sqn;
> > +	uint32_t i, k, n = num;
> 
> You can just do s/num/n/ in function parameter list, then you don't need to
> keep 'num' at all.

This function will be called for normal IPsec processing. The function esn_outb_update_sqn() updates the local variable n passed as parameter in OVERFLOW case. If we remove the local variable n, this error path would be lost and it is not our intention I believe.

> 
> >  	rte_be64_t sqc;
> >  	struct rte_ipsec_sa *sa;
> >  	struct rte_cryptodev_sym_session *cs; @@ -305,11 +304,6 @@
> > esp_outb_tun_prepare(const struct rte_ipsec_session *ss, struct rte_mbuf
> *mb[],
> >  	sa = ss->sa;
> >  	cs = ss->crypto.ses;
> >
> > -	n = num;
> > -	sqn = esn_outb_update_sqn(sa, &n);
> > -	if (n != num)
> > -		rte_errno = EOVERFLOW;
> > -
> >  	k = 0;
> >  	for (i = 0; i != n; i++) {
> >
> > @@ -339,6 +333,30 @@ esp_outb_tun_prepare(const struct
> rte_ipsec_session *ss, struct rte_mbuf *mb[],
> >  	return k;
> >  }
> >
> > +uint16_t
> > +esp_outb_tun_prepare(const struct rte_ipsec_session *ss, struct rte_mbuf
> *mb[],
> > +	struct rte_crypto_op *cop[], uint16_t num) {
> > +	uint64_t sqn;
> > +	uint32_t n;
> > +
> > +	n = num;
> > +	sqn = esn_outb_update_sqn(ss->sa, &n);
> > +	if (n != num)
> > +		rte_errno = EOVERFLOW;
> > +
> > +	return esp_outb_tun_prepare_helper(ss, mb, cop, n, sqn); }
> > +
> > +uint16_t
> > +esp_outb_tun_prepare_stateless(const struct rte_ipsec_session *ss, struct
> rte_mbuf *mb[],
> > +	struct rte_crypto_op *cop[], uint16_t num, struct rte_ipsec_state
> > +*state) {
> > +	uint64_t sqn = state->sqn;
> > +
> > +	return esp_outb_tun_prepare_helper(ss, mb, cop, num, sqn); }
> > +
> >  /*
> >   * setup/update packet data and metadata for ESP outbound transport case.
> >   */
> > @@ -529,16 +547,15 @@ outb_cpu_crypto_prepare(const struct
> rte_ipsec_sa *sa, uint32_t *pofs,
> >  	return clen;
> >  }
> >
> > -static uint16_t
> > -cpu_outb_pkt_prepare(const struct rte_ipsec_session *ss,
> > -		struct rte_mbuf *mb[], uint16_t num,
> > -		esp_outb_prepare_t prepare, uint32_t cofs_mask)
> > +static inline uint16_t
> > +cpu_outb_pkt_prepare_helper(const struct rte_ipsec_session *ss,
> > +		struct rte_mbuf *mb[], uint16_t num, esp_outb_prepare_t
> prepare,
> > +		uint32_t cofs_mask,	uint64_t sqn)
> >  {
> >  	int32_t rc;
> > -	uint64_t sqn;
> >  	rte_be64_t sqc;
> >  	struct rte_ipsec_sa *sa;
> > -	uint32_t i, k, n;
> > +	uint32_t i, k, n = num;
> 
> Same here, you can just use 'n' instead of 'num'.

Same comment as above.

> 
> >  	uint32_t l2, l3;
> >  	union sym_op_data icv;
> >  	struct rte_crypto_va_iova_ptr iv[num]; @@ -551,11 +568,6 @@
> > cpu_outb_pkt_prepare(const struct rte_ipsec_session *ss,
> >
> >  	sa = ss->sa;
> >
> > -	n = num;
> > -	sqn = esn_outb_update_sqn(sa, &n);
> > -	if (n != num)
> > -		rte_errno = EOVERFLOW;
> > -
> >  	for (i = 0, k = 0; i != n; i++) {
> >
> >  		l2 = mb[i]->l2_len;
> > @@ -604,15 +616,40 @@ uint16_t
> >  cpu_outb_tun_pkt_prepare(const struct rte_ipsec_session *ss,
> >  		struct rte_mbuf *mb[], uint16_t num)  {
> > -	return cpu_outb_pkt_prepare(ss, mb, num, outb_tun_pkt_prepare,
> 0);
> > +	uint64_t sqn;
> > +	uint32_t n;
> > +
> > +	n = num;
> > +	sqn = esn_outb_update_sqn(ss->sa, &n);
> > +	if (n != num)
> > +		rte_errno = EOVERFLOW;
> > +
> > +	return cpu_outb_pkt_prepare_helper(ss, mb, n,
> outb_tun_pkt_prepare,
> > +0, sqn); }
> > +
> > +uint16_t
> > +cpu_outb_tun_pkt_prepare_stateless(const struct rte_ipsec_session *ss,
> > +		struct rte_mbuf *mb[], uint16_t num, struct rte_ipsec_state
> *state)
> > +{
> > +	uint64_t sqn = state->sqn;
> > +
> > +	return cpu_outb_pkt_prepare_helper(ss, mb, num,
> > +outb_tun_pkt_prepare, 0, sqn);
> >  }
> >
> >  uint16_t
> >  cpu_outb_trs_pkt_prepare(const struct rte_ipsec_session *ss,
> >  		struct rte_mbuf *mb[], uint16_t num)  {
> > -	return cpu_outb_pkt_prepare(ss, mb, num, outb_trs_pkt_prepare,
> > -		UINT32_MAX);
> > +	uint64_t sqn;
> > +	uint32_t n;
> > +
> > +	n = num;
> > +	sqn = esn_outb_update_sqn(ss->sa, &n);
> > +	if (n != num)
> > +		rte_errno = EOVERFLOW;
> > +
> > +	return cpu_outb_pkt_prepare_helper(ss, mb, n,
> outb_trs_pkt_prepare,
> > +		UINT32_MAX, sqn);
> >  }
> >
> >  /*
> > diff --git a/lib/ipsec/rte_ipsec.h b/lib/ipsec/rte_ipsec.h index
> > f15f6f2966..b462068203 100644
> > --- a/lib/ipsec/rte_ipsec.h
> > +++ b/lib/ipsec/rte_ipsec.h
> > @@ -23,11 +23,26 @@ extern "C" {
> >
> >  struct rte_ipsec_session;
> >
> > +/**
> > + * IPsec state for stateless processing of a batch of IPsec packets.
> > + */
> > +struct rte_ipsec_state {
> > +	union {
> 
> Curious what is the purpose of 'union' here?
> What other mutually exclusive fields you plan to add here?
> 
> > +		/**
> > +		 * 64 bit sequence number to be used for the first packet of
> the
> > +		 * batch of packets.
> > +		 */
> > +		uint64_t sqn;
> > +	};
> > +};
> > +
> >  /**
> >   * IPsec session specific functions that will be used to:
> >   * - prepare - for input mbufs and given IPsec session prepare crypto ops
> >   *   that can be enqueued into the cryptodev associated with given session
> >   *   (see *rte_ipsec_pkt_crypto_prepare* below for more details).
> > + * - prepare_stateless - similar to prepare, but further processing is done
> > + *   based on IPsec state provided by the 'state' parameter.
> >   * - process - finalize processing of packets after crypto-dev finished
> >   *   with them or process packets that are subjects to inline IPsec offload
> >   *   (see rte_ipsec_pkt_process for more details).
> > @@ -42,6 +57,17 @@ struct rte_ipsec_sa_pkt_func {
> >  				struct rte_mbuf *mb[],
> >  				uint16_t num);
> >  	} prepare;
> > +	union {
> > +		uint16_t (*async)(const struct rte_ipsec_session *ss,
> > +				struct rte_mbuf *mb[],
> > +				struct rte_crypto_op *cop[],
> > +				uint16_t num,
> > +				struct rte_ipsec_state *state);
> > +		uint16_t (*sync)(const struct rte_ipsec_session *ss,
> > +				struct rte_mbuf *mb[],
> > +				uint16_t num,
> > +				struct rte_ipsec_state *state);
> > +	} prepare_stateless;
> >  	uint16_t (*process)(const struct rte_ipsec_session *ss,
> >  				struct rte_mbuf *mb[],
> >  				uint16_t num);
> > @@ -128,6 +154,48 @@ rte_ipsec_pkt_cpu_prepare(const struct
> rte_ipsec_session *ss,
> >  	return ss->pkt_func.prepare.sync(ss, mb, num);  }
> >
> > +/**
> > + * Same as rte_ipsec_pkt_crypto_prepare, but processing is done based
> > +on
> > + * IPsec state provided by the 'state' parameter. Internal IPsec
> > +state won't
> > + * be updated when this API is called.
> > + *
> > + * For input mbufs and given IPsec session prepare crypto ops that
> > +can be
> > + * enqueued into the cryptodev associated with given session.
> > + * expects that for each input packet:
> > + *      - l2_len, l3_len are setup correctly
> > + * Note that erroneous mbufs are not freed by the function,
> > + * but are placed beyond last valid mbuf in the *mb* array.
> > + * It is a user responsibility to handle them further.
> > + * @param ss
> > + *   Pointer to the *rte_ipsec_session* object the packets belong to.
> > + * @param mb
> > + *   The address of an array of *num* pointers to *rte_mbuf* structures
> > + *   which contain the input packets.
> > + * @param cop
> > + *   The address of an array of *num* pointers to the output
> *rte_crypto_op*
> > + *   structures.
> > + * @param num
> > + *   The maximum number of packets to process.
> > + * @param state
> > + *   The IPsec state to be used for processing current batch of packets.
> > + * @return
> > + *   Number of successfully processed packets, with error code set in
> rte_errno.
> > + */
> 
> We probably need to mark new API as 'rte_experimental'.

Ack. Will update in v3.

> 
> > +static inline uint16_t
> > +rte_ipsec_pkt_crypto_prepare_stateless(const struct rte_ipsec_session *ss,
> > +	struct rte_mbuf *mb[], struct rte_crypto_op *cop[], uint16_t num,
> > +	struct rte_ipsec_state *state)
> > +{
> > +	return ss->pkt_func.prepare_stateless.async(ss, mb, cop, num,
> > +state); }
> > +
> > +static inline uint16_t
> > +rte_ipsec_pkt_cpu_prepare_stateless(const struct rte_ipsec_session *ss,
> > +	struct rte_mbuf *mb[], uint16_t num, struct rte_ipsec_state *state)
> > +{
> > +	return ss->pkt_func.prepare_stateless.sync(ss, mb, num, state); }
> > +
> >  /**
> >   * Finalise processing of packets after crypto-dev finished with them or
> >   * process packets that are subjects to inline IPsec offload.
> > diff --git a/lib/ipsec/sa.c b/lib/ipsec/sa.c index
> > 2297bd6d72..741e079831 100644
> > --- a/lib/ipsec/sa.c
> > +++ b/lib/ipsec/sa.c
> > @@ -710,6 +710,7 @@ lksd_none_pkt_func_select(const struct
> rte_ipsec_sa *sa,
> >  	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV4):
> >  	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV6):
> >  		pf->prepare.async = esp_outb_tun_prepare;
> > +		pf->prepare_stateless.async =
> esp_outb_tun_prepare_stateless;
> >  		pf->process = (sa->sqh_len != 0) ?
> >  			esp_outb_sqh_process : pkt_flag_process;
> >  		break;
> > @@ -748,6 +749,7 @@ cpu_crypto_pkt_func_select(const struct
> rte_ipsec_sa *sa,
> >  	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV4):
> >  	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV6):
> >  		pf->prepare.sync = cpu_outb_tun_pkt_prepare;
> > +		pf->prepare_stateless.sync =
> cpu_outb_tun_pkt_prepare_stateless;
> >  		pf->process = (sa->sqh_len != 0) ?
> >  			esp_outb_sqh_process : pkt_flag_process;
> >  		break;
> > @@ -810,7 +812,7 @@ ipsec_sa_pkt_func_select(const struct
> rte_ipsec_session *ss,
> >  	int32_t rc;
> >
> >  	rc = 0;
> > -	pf[0] = (struct rte_ipsec_sa_pkt_func) { {NULL}, NULL };
> > +	pf[0] = (struct rte_ipsec_sa_pkt_func) { {NULL}, {NULL}, NULL };
> >
> >  	switch (ss->type) {
> >  	case RTE_SECURITY_ACTION_TYPE_NONE:
> > diff --git a/lib/ipsec/sa.h b/lib/ipsec/sa.h index
> > 719b5c735c..9b53586b2d 100644
> > --- a/lib/ipsec/sa.h
> > +++ b/lib/ipsec/sa.h
> > @@ -179,6 +179,10 @@ uint16_t
> >  esp_outb_tun_prepare(const struct rte_ipsec_session *ss, struct rte_mbuf
> *mb[],
> >  	struct rte_crypto_op *cop[], uint16_t num);
> >
> > +uint16_t
> > +esp_outb_tun_prepare_stateless(const struct rte_ipsec_session *ss, struct
> rte_mbuf *mb[],
> > +	struct rte_crypto_op *cop[], uint16_t num, struct rte_ipsec_state
> > +*state);
> > +
> >  uint16_t
> >  esp_outb_trs_prepare(const struct rte_ipsec_session *ss, struct rte_mbuf
> *mb[],
> >  	struct rte_crypto_op *cop[], uint16_t num); @@ -207,6 +211,10 @@
> > uint16_t  cpu_outb_tun_pkt_prepare(const struct rte_ipsec_session *ss,
> >  		struct rte_mbuf *mb[], uint16_t num);  uint16_t
> > +cpu_outb_tun_pkt_prepare_stateless(const struct rte_ipsec_session *ss,
> > +		struct rte_mbuf *mb[], uint16_t num, struct rte_ipsec_state
> > +*state);
> > +
> > +uint16_t
> >  cpu_outb_trs_pkt_prepare(const struct rte_ipsec_session *ss,
> >  		struct rte_mbuf *mb[], uint16_t num);
> >
> > --
> > 2.25.1