[PATCH rdma-core 04/11] verbs: Add a man page for flow_action_esp

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From: Boris Pismenny <borisp@xxxxxxxxxxxx>

Added man pages for ibv_create_flow_action_esp,
ibv_modify_flow_action_esp and ibv_destroy_flow_action.

Signed-off-by: Boris Pismenny <borisp@xxxxxxxxxxxx>
Signed-off-by: Matan Barak <matanb@xxxxxxxxxxxx>
Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxxxx>
---
 libibverbs/man/CMakeLists.txt              |   3 +
 libibverbs/man/ibv_create_flow_action.3.md | 338 +++++++++++++++++++++++++++++
 2 files changed, 341 insertions(+)
 create mode 100644 libibverbs/man/ibv_create_flow_action.3.md

diff --git a/libibverbs/man/CMakeLists.txt b/libibverbs/man/CMakeLists.txt
index aa245ba..743e57b 100644
--- a/libibverbs/man/CMakeLists.txt
+++ b/libibverbs/man/CMakeLists.txt
@@ -13,6 +13,7 @@ rdma_man_pages(
   ibv_create_cq_ex.3
   ibv_modify_cq.3
   ibv_create_flow.3
+  ibv_create_flow_action.3.md
   ibv_create_qp.3
   ibv_create_qp_ex.3
   ibv_create_rwq_ind_table.3
@@ -72,6 +73,8 @@ rdma_alias_man_pages(
   ibv_create_comp_channel.3 ibv_destroy_comp_channel.3
   ibv_create_cq.3 ibv_destroy_cq.3
   ibv_create_flow.3 ibv_destroy_flow.3
+  ibv_create_flow_action.3 ibv_destroy_flow_action.3
+  ibv_create_flow_action.3 ibv_modify_flow_action.3
   ibv_create_qp.3 ibv_destroy_qp.3
   ibv_create_rwq_ind_table.3 ibv_destroy_rwq_ind_table.3
   ibv_create_srq.3 ibv_destroy_srq.3
diff --git a/libibverbs/man/ibv_create_flow_action.3.md b/libibverbs/man/ibv_create_flow_action.3.md
new file mode 100644
index 0000000..16881c3
--- /dev/null
+++ b/libibverbs/man/ibv_create_flow_action.3.md
@@ -0,0 +1,338 @@
+---
+layout: page
+title: ibv_flow_action_esp(3)
+section: 3
+tagline: Verbs
+---
+
+# NAME
+
+ibv_flow_action_esp(3) -- Flow action esp for verbs(3)
+
+# SYNOPSIS
+
+```c
+#include <infiniband/verbs.h>
+
+struct ibv_flow_action *
+ibv_create_flow_action_esp(struct ibv_context *ctx,
+			   struct ibv_flow_action_esp *esp);
+int
+ibv_modify_flow_action_esp(struct ibv_flow_action *action,
+			   struct ibv_flow_action_esp *esp);
+
+int ibv_destroy_flow_action(struct ibv_flow_action *action);
+```
+
+# DESCRIPTION
+
+An IPSEC ESP flow steering action allows a flow steering rule to decrypt or
+encrypt a packet after matching. Each action contains the necessary
+information for this operation in the *params* argument.
+
+After the crypto operation the packet will continue to be processed by flow
+steering rules until it reaches a final action of discard or delivery.
+
+After the action is created, then it should be associated with a *struct
+ibv_flow_attr* using *struct ibv_flow_spec_action_handle* flow specification.
+Each action can be associated with multiple flows, and *ibv_modify_flow_action_esp*
+will alter all associated flows simultaneously.
+
+# ARGUMENTS
+
+*ctx*
+:	RDMA device context to create the action on.
+
+*esp*
+:	ESP parameters and key material for the action.
+
+*action*
+:	Existing action to modify ESP parameters.
+
+## *action* Argument
+
+```c
+struct ibv_flow_action_esp {
+	struct ibv_flow_action_esp_attr *esp_attr;
+
+	/* See Key Material */
+	uint16_t		keymat_proto;
+	uint16_t		keymat_len;
+	void		   *keymat_ptr;
+
+	/* See Replay Protection */
+	uint16_t        replay_proto;
+	uint16_t        replay_len;
+	void           *replay_ptr;
+
+	struct ibv_flow_action_esp_encap *esp_encap;
+
+	uint32_t		comp_mask;
+	uint32_t		esn;
+};
+```
+
+*comp_mask*
+:	Bitmask specifying what fields in the structure are valid.
+
+*esn*
+:	The starting value of the ESP extended sequence number.
+	Valid only if *IBV_FLOW_ACTION_ESP_MASK_ESN* is set in *comp_mask*.
+
+	The 32 bits of *esn* will be used to compute the full 64 bit ESN
+	required for the AAD construction.
+
+	When in *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_INLINE_CRYPTO* mode, the
+	implementation will automatically track rollover of the lower 32 bits
+	of the ESN. However, an update of the window is required once every
+	2^31 sequences.
+
+	When in *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLOAD* mode this value is
+	automatically incremended and it is also used for anti-replay checks.
+
+*esp_attr*
+:	See *ESP Attributes*. May be NULL on modify.
+
+*keymat_proto*, *keymat_len*, *keymat_ptr*
+:	Describe the key material and encryption standard to use. May be NULL on
+	modify.
+
+*replay_proto*, *replay_len*, *replay_ptr*
+:	Describe the replay protection scheme used to manage sequence numbers and
+	prevent replay attacks. This field is only valid in full offload mode.
+	May be NULL on modify.
+
+*esp_encap*
+:	Describe the encapsulation of ESP packets such as the IP tunnel and/or
+	UDP encapsulation. This field is only valid in full offload mode.
+	May be NULL on modify.
+
+##  ESP attributes
+
+```c
+struct ibv_flow_action_esp_attr {
+	uint32_t   spi;
+	uint32_t   seq;
+	uint32_t   tfc_pad;
+	uint32_t   flags;
+	uint64_t   hard_limit_pkts;
+};
+```
+
+*flags*
+:	A bitwise OR of the various *IB_UVERBS_FLOW_ACTION_ESP_FLAGS* described below.
+
+	*IB_UVERBS_FLOW_ACTION_ESP_FLAGS_DECRYPT*, *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_ENCRYPT*
+	:	The action will decrypt or encrypt a packet using the provided
+		keying material.
+
+		The implementation may require that encrypt is only used with an
+		egress flow steering rule, and that decrypt is only used with an
+		ingress flow steering rule.
+
+## Full Offload Mode
+
+When *esp_attr* flag *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLOAD* is set the
+ESP header and trailer are added and removed automatically during the cipher
+operation.  In this case the *esn* and *spi* are used to populate and check
+the ESP header, and any information from the *keymat* (eg a IV) is placed in
+the headers and otherwise handled automatically.
+
+For decrypt the hardware will perform anti-replay.
+
+Decryption failure will cause the packet to be dropped.
+
+This action must be combined with the flow steering that identifies the
+packets protected by the SA defined in this action.
+
+The following members of the esp_attr are used only in full offload mode:
+
+*spi*
+:	The value for the ESP Security Paremeters Index.
+	It is only used for *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLAOD*.
+
+*seq*
+:	The initial 32 lower bytes of the sequence number.
+	This is the value of the ESP sequence number.
+	It is only used for *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLAOD*.
+
+*tfc_pad*
+:	The length of Traffic Flow Confidentiality Padding as specified by
+	RFC4303. If it is set to zero no additional padding is added.
+	It is only used for *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLAOD*. 
+
+*hard_limit_pkts*
+: 	The hard lifetime of the SA measured in number of packets.
+	As specified by RFC4301.
+	After this limit is reached the action will drop future packets
+	to prevent breaking the crypto.
+	It is only used for *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLAOD*. 
+
+## Inline Crypto Mode
+
+When *esp_attr* flag *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_INLINE_CRYPTO* is set
+the user must providate packets with additional headers.
+
+For encrypt the packet must contain a fully populated IPSEC packet except the
+data payload is left un-encrypted and there is no IPsec trailer.
+If the IV must be unpredictable, then a flag should indicate the transofrmation
+such as *IB_UVERBS_FLOW_ACTION_IV_ALGO_SEQ*.
+
+*IB_UVERBS_FLOW_ACTION_IV_ALGO_SEQ* means that the IV is incremented
+sequentually. If the IV algorithm is supported by HW, then it could provide
+support for LSO offload with ESP inline crypto.
+
+Finally, the IV used to encrypt the packet replaces the IV field provided, the
+payload is encrypted and authenticated, a trailer with padding is added and
+the ICV is added as well.
+
+For decrypt the packet is authenticated and decrypted in-place, resulting in a
+decrypted IPSEC packet with no trailer. The result of decryption and
+authentication can be retrieved from an extended CQ via the
+*ibv_wc_read_XXX(3)* function.
+
+This mode must be combined with the flow steering including
+*IBV_FLOW_SPEC_IPV4* and *IBV_FLOW_SPEC_ESP* to match the outer packet headers
+to ensure that the action is only applied to IPSEC packets with the correct
+identifiers.
+
+For inline crypto, we have some special requirements to maintain a stateless
+ESN while maintaining the same parameters as software. The system supports
+offloading a portion of the IPSEC flow, enabling a single flow to be split
+between multiple NICs.
+
+### Determining the ESN for Ingress Packets
+
+We require a "modify" command once every 2^31 packets. This
+modify command allows the implementation in HW to be stateless, as follows:
+
+```
+           ESN 1                       ESN 2                      ESN 3
+|-------------*-------------|-------------*-------------|-------------*
+^             ^             ^             ^             ^             ^
+```
+
+^ - marks where command invoked to update the SA ESN state machine.  
+| - marks the start of the ESN scope (0-2^32-1). At this point move SA ESN "new_window" bit to zero and increment ESN.  
+* - marks the middle of the ESN scope (2^31). At this point move SA ESN "new_window" bit to one.
+
+For decryption the implementation uses the following state machine to determine ESN:
+
+```c
+if (!overlap) {
+	use esn // regardless of packet.seq
+} else { // new_window
+	if (packet.seq >= 2^31)
+		use esn
+	else // packet.seq < 2^31
+		use esn+1
+}
+```
+
+This mechanism is controled by the *esp_attr* flag:
+
+*IB_UVERBS_FLOW_ACTION_ESP_FLAGS_ESN_NEW_WINDOW*
+: 	This flag is only used to provide stateless ESN support for inline crypto.
+	It is used only for *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_INLINE_CRYPTO* and
+	*IBV_FLOW_ACTION_ESP_MASK_ESN*.
+	
+	Setting this flag indicates that the bottom of the replay window is
+	between 2^31 - 2^32.
+
+## Key Material for AES GCM (*IBV_ACTION_ESP_KEYMAT_AES_GCM*)
+
+The AES GCM crypto algorithm as defined by RFC4106. This struct is to be
+provided in *keymat_ptr* when *keymat_proto* is set to
+*IBV_ACTION_ESP_KEYMAT_AES_GCM*.
+
+```c
+struct ibv_flow_action_esp_aes_keymat_aes_gcm {
+	uint64_t   iv;
+	uint32_t   iv_algo; /* Use enum ib_uverbs_flow_action_esp_aes_gcm_keymat_iv_algo */
+
+	uint32_t   salt;
+	uint32_t   icv_len;
+
+	uint32_t   key_len;
+	uint32_t   aes_key[256 / 32];
+};
+```
+
+*iv*
+:	The starting value for the initialization vector used only with
+	*IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLOAD* encryption as defined in
+	RFC4106. This field is ignored for
+	*IB_UVERBS_FLOW_ACTION_ESP_FLAGS_INLINE_CRYPTO*.
+
+	For a given key, the IV MUST NOT be reused.
+
+*iv_algo*
+:	The algorithm used to transform/generate new IVs with
+	*IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLOAD* encyption.
+
+	The only supported value is *IB_UVERBS_FLOW_ACTION_IV_ALGO_SEQ* to
+	generate sequantial IVs.
+
+*salt*
+:	The salt as defined by RFC4106.
+
+*icv_len*
+:	The length of the Integrity Check Value in bytes as defined by RFC4106.
+
+*aes_key*, *key_len*
+:	The cipher key data. It must be either 16, 24 or 32 bytes as defined by RFC4106.
+
+## Bitmap Replay Protection (*IBV_FLOW_ACTION_ESP_REPLAY_BMP*)
+
+A shifting bitmap is used to identify which packets have already been
+transmitted. Each bit in the bitmap represents a packet, it is set if a packet
+with this ESP sequence number has been received and it passed authentication.
+If a packet with the same sequence is received, then the bit is already set,
+causing replay protection to drop the packet.  The bitmap represents a window
+of *size* sequence numbers. If a newer sequence number is received, then the
+bitmap will shift to represent this as in RFC6479.  The replay window cannot
+shift more than 2^31 sequence numbers forward.
+
+This struct is to be provided in *replay_ptr* when *reply_proto* is set to
+*IBV_FLOW_ACTION_ESP_REPLAY_BMP*. In this mode reply_ptr and reply_len should
+point to a struct ibv_flow_action_esp_replay_bmp containing:
+	*size*
+:	The size of the bitmap.
+
+## ESP Encapsulation
+
+An *esp_encap* specification is required when *eps_attr* flags
+*IB_UVERBS_FLOW_ACTION_ESP_FLAGS_TUNNEL* is set. It is used to provide the fields
+for the encapsulation header that is added/removed to/from packets.
+Tunnel and Transport mode are defined as in RFC4301.
+UDP encapsulation of ESP can be specified by providing the appropriate UDP header.
+
+This setting is only used in *IB_UVERBS_FLOW_ACTION_ESP_FLAGS_FULL_OFFLOAD*
+mode.
+
+```C
+struct ibv_flow_action_esp_encap {
+	void		*val;        /* pointer to struct ibv_flow_xxxx_filter */
+	struct ibv_flow_action_esp_encap   *next_ptr;
+	uint16_t	len;            /* Len of mask and pointer (separately) */
+	uint16_t	type;           /* Use flow_spec enum */
+};
+```
+
+Each link in the list specifies a network header in the same manner as the flow steering API.
+The header should be selected from a supported header in 'enum ibv_flow_spec_type'.
+
+# RETURN VALUE
+
+Upon success *ibv_create_flow_action_esp* will return a new *struct
+ibv_flow_action* object, on error NULL will be returned and errno will be set.
+
+Upon success *ibv_modify_action_esp* will return 0. On error the value of
+errno will be returned. If ibv_modify_flow_action fails, it is guarnteed that
+the last action still holds. If it succeeds, there is a point in the future
+where the old action is applied on all packets until this point and the new
+one is applied on all packets from this point and on.
+
+# SEE ALSO
+
+*ibv_create_flow(3)*,  *ibv_destroy_action(3)*, *RFC 4106*
-- 
1.8.3.1

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