[dpdk-dev] [PATCH v7 3/5] ipsec: add SAD add/delete/lookup implementation

[Vladimir Medvedkin]

Replace rte_ipsec_sad_add(), rte_ipsec_sad_del() and
rte_ipsec_sad_lookup() stubs with actual implementation.

It uses three librte_hash tables each of which contains
an entries for a specific SA type (either it is addressed by SPI only
or SPI+DIP or SPI+DIP+SIP)

Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin at intel.com>
Acked-by: Akhil Goyal <akhil.goyal at nxp.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
Tested-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
 doc/guides/prog_guide/ipsec_lib.rst | 110 ++++++++++++++
 lib/librte_ipsec/ipsec_sad.c        | 278 ++++++++++++++++++++++++++++++++++--
 2 files changed, 376 insertions(+), 12 deletions(-)

diff --git a/doc/guides/prog_guide/ipsec_lib.rst b/doc/guides/prog_guide/ipsec_lib.rst
index b69c153..4487e4c 100644
--- a/doc/guides/prog_guide/ipsec_lib.rst
+++ b/doc/guides/prog_guide/ipsec_lib.rst
@@ -186,6 +186,116 @@ As an example:
 
     for more information please refer to ipsec library API reference
 
+Add/delete rules
+~~~~~~~~~~~~~~~~
+
+Library also provides methods to add or delete key/value pairs from the SAD.
+To add user has to specify key, key type and a value which is an opaque pointer to SA.
+The key type reflects a set of tuple fields that will be used for lookup of the SA.
+As mentioned above there are 3 types of a key and the representation of a key type is:
+
+.. code-block:: c
+
+        RTE_IPSEC_SAD_SPI_ONLY,
+        RTE_IPSEC_SAD_SPI_DIP,
+        RTE_IPSEC_SAD_SPI_DIP_SIP,
+
+As an example, to add new entry into the SAD for IPv4 addresses:
+
+.. code-block:: c
+
+    struct rte_ipsec_sa *sa;
+    union rte_ipsec_sad_key key;
+
+    key.v4.spi = rte_cpu_to_be_32(spi_val);
+    if (key_type >= RTE_IPSEC_SAD_SPI_DIP) /* DIP is optional*/
+        key.v4.dip = rte_cpu_to_be_32(dip_val);
+    if (key_type == RTE_IPSEC_SAD_SPI_DIP_SIP) /* SIP is optional*/
+        key.v4.sip = rte_cpu_to_be_32(sip_val);
+
+    rte_ipsec_sad_add(sad, &key, key_type, sa);
+
+.. note::
+
+    By performance reason it is better to keep spi/dip/sip in net byte order
+    to eliminate byteswap on lookup
+
+To delete user has to specify key and key type.
+
+Delete code would look like:
+
+.. code-block:: c
+
+    union rte_ipsec_sad_key key;
+
+    key.v4.spi = rte_cpu_to_be_32(necessary_spi);
+    if (key_type >= RTE_IPSEC_SAD_SPI_DIP) /* DIP is optional*/
+        key.v4.dip = rte_cpu_to_be_32(necessary_dip);
+    if (key_type == RTE_IPSEC_SAD_SPI_DIP_SIP) /* SIP is optional*/
+        key.v4.sip = rte_cpu_to_be_32(necessary_sip);
+
+    rte_ipsec_sad_del(sad, &key, key_type);
+
+
+Lookup
+~~~~~~
+Library provides lookup by the given {SPI,DIP,SIP} tuple of
+inbound ipsec packet as a key.
+
+The search key is represented by:
+
+.. code-block:: c
+
+    union rte_ipsec_sad_key {
+        struct rte_ipsec_sadv4_key  v4;
+        struct rte_ipsec_sadv6_key  v6;
+    };
+
+where v4 is a tuple for IPv4:
+
+.. code-block:: c
+
+    struct rte_ipsec_sadv4_key {
+        uint32_t spi;
+        uint32_t dip;
+        uint32_t sip;
+    };
+
+and v6 is a tuple for IPv6:
+
+.. code-block:: c
+
+    struct rte_ipsec_sadv6_key {
+        uint32_t spi;
+        uint8_t dip[16];
+        uint8_t sip[16];
+    };
+
+As an example, lookup related code could look like that:
+
+.. code-block:: c
+
+    int i;
+    union rte_ipsec_sad_key keys[BURST_SZ];
+    const union rte_ipsec_sad_key *keys_p[BURST_SZ];
+    void *vals[BURST_SZ];
+
+    for (i = 0; i < BURST_SZ_MAX; i++) {
+        keys[i].v4.spi = esp_hdr[i]->spi;
+        keys[i].v4.dip = ipv4_hdr[i]->dst_addr;
+        keys[i].v4.sip = ipv4_hdr[i]->src_addr;
+        keys_p[i] = &keys[i];
+    }
+    rte_ipsec_sad_lookup(sad, keys_p, vals, BURST_SZ);
+
+    for (i = 0; i < BURST_SZ_MAX; i++) {
+        if (vals[i] == NULL)
+            printf("SA not found for key index %d\n", i);
+        else
+            printf("SA pointer is %p\n", vals[i]);
+    }
+
+
 Supported features
 ------------------
 
diff --git a/lib/librte_ipsec/ipsec_sad.c b/lib/librte_ipsec/ipsec_sad.c
index e16c7d9..db2c44c 100644
--- a/lib/librte_ipsec/ipsec_sad.c
+++ b/lib/librte_ipsec/ipsec_sad.c
@@ -49,20 +49,182 @@ static struct rte_tailq_elem rte_ipsec_sad_tailq = {
 };
 EAL_REGISTER_TAILQ(rte_ipsec_sad_tailq)
 
+#define SET_BIT(ptr, bit)	(void *)((uintptr_t)(ptr) | (uintptr_t)(bit))
+#define CLEAR_BIT(ptr, bit)	(void *)((uintptr_t)(ptr) & ~(uintptr_t)(bit))
+#define GET_BIT(ptr, bit)	(void *)((uintptr_t)(ptr) & (uintptr_t)(bit))
+
+/*
+ * @internal helper function
+ * Add a rule of type SPI_DIP or SPI_DIP_SIP.
+ * Inserts a rule into an appropriate hash table,
+ * updates the value for a given SPI in SPI_ONLY hash table
+ * reflecting presence of more specific rule type in two LSBs.
+ * Updates a counter that reflects the number of rules whith the same SPI.
+ */
+static inline int
+add_specific(struct rte_ipsec_sad *sad, const void *key,
+		int key_type, void *sa)
+{
+	void *tmp_val;
+	int ret, notexist;
+
+	/* Check if the key is present in the table.
+	 * Need for further accaunting in cnt_arr
+	 */
+	ret = rte_hash_lookup(sad->hash[key_type], key);
+	notexist = (ret == -ENOENT);
+
+	/* Add an SA to the corresponding table.*/
+	ret = rte_hash_add_key_data(sad->hash[key_type], key, sa);
+	if (ret != 0)
+		return ret;
+
+	/* Check if there is an entry in SPI only table with the same SPI */
+	ret = rte_hash_lookup_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
+		key, &tmp_val);
+	if (ret < 0)
+		tmp_val = NULL;
+	tmp_val = SET_BIT(tmp_val, key_type);
+
+	/* Add an entry into SPI only table */
+	ret = rte_hash_add_key_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
+		key, tmp_val);
+	if (ret != 0)
+		return ret;
+
+	/* Update a counter for a given SPI */
+	ret = rte_hash_lookup(sad->hash[RTE_IPSEC_SAD_SPI_ONLY], key);
+	if (key_type == RTE_IPSEC_SAD_SPI_DIP)
+		sad->cnt_arr[ret].cnt_dip += notexist;
+	else
+		sad->cnt_arr[ret].cnt_dip_sip += notexist;
+
+	return 0;
+}
+
 int
-rte_ipsec_sad_add(__rte_unused struct rte_ipsec_sad *sad,
-		__rte_unused const union rte_ipsec_sad_key *key,
-		__rte_unused int key_type, __rte_unused void *sa)
+rte_ipsec_sad_add(struct rte_ipsec_sad *sad,
+		const union rte_ipsec_sad_key *key,
+		int key_type, void *sa)
 {
-	return -ENOTSUP;
+	void *tmp_val;
+	int ret;
+
+	if ((sad == NULL) || (key == NULL) || (sa == NULL) ||
+			/* sa must be 4 byte aligned */
+			(GET_BIT(sa, RTE_IPSEC_SAD_KEY_TYPE_MASK) != 0))
+		return -EINVAL;
+
+	/*
+	 * Rules are stored in three hash tables depending on key_type.
+	 * All rules will also have an entry in SPI_ONLY table, with entry
+	 * value's two LSB's also indicating presence of rule with this SPI
+	 * in other tables.
+	 */
+	switch (key_type) {
+	case(RTE_IPSEC_SAD_SPI_ONLY):
+		ret = rte_hash_lookup_data(sad->hash[key_type],
+			key, &tmp_val);
+		if (ret >= 0)
+			tmp_val = SET_BIT(sa, GET_BIT(tmp_val,
+				RTE_IPSEC_SAD_KEY_TYPE_MASK));
+		else
+			tmp_val = sa;
+		ret = rte_hash_add_key_data(sad->hash[key_type],
+			key, tmp_val);
+		return ret;
+	case(RTE_IPSEC_SAD_SPI_DIP):
+	case(RTE_IPSEC_SAD_SPI_DIP_SIP):
+		return add_specific(sad, key, key_type, sa);
+	default:
+		return -EINVAL;
+	}
+}
+
+/*
+ * @internal helper function
+ * Delete a rule of type SPI_DIP or SPI_DIP_SIP.
+ * Deletes an entry from an appropriate hash table and decrements
+ * an entry counter for given SPI.
+ * If entry to remove is the last one with given SPI within the table,
+ * then it will also update related entry in SPI_ONLY table.
+ * Removes an entry from SPI_ONLY hash table if there no rule left
+ * for this SPI in any table.
+ */
+static inline int
+del_specific(struct rte_ipsec_sad *sad, const void *key, int key_type)
+{
+	void *tmp_val;
+	int ret;
+	uint32_t *cnt;
+
+	/* Remove an SA from the corresponding table.*/
+	ret = rte_hash_del_key(sad->hash[key_type], key);
+	if (ret < 0)
+		return ret;
+
+	/* Get an index of cnt_arr entry for a given SPI */
+	ret = rte_hash_lookup_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
+		key, &tmp_val);
+	if (ret < 0)
+		return ret;
+	cnt = (key_type == RTE_IPSEC_SAD_SPI_DIP) ?
+			&sad->cnt_arr[ret].cnt_dip :
+			&sad->cnt_arr[ret].cnt_dip_sip;
+	if (--(*cnt) != 0)
+		return 0;
+
+	/* corresponding counter is 0, clear the bit indicating
+	 * the presence of more specific rule for a given SPI.
+	 */
+	tmp_val = CLEAR_BIT(tmp_val, key_type);
+
+	/* if there are no rules left with same SPI,
+	 * remove an entry from SPI_only table
+	 */
+	if (tmp_val == NULL)
+		ret = rte_hash_del_key(sad->hash[RTE_IPSEC_SAD_SPI_ONLY], key);
+	else
+		ret = rte_hash_add_key_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
+			key, tmp_val);
+	if (ret < 0)
+		return ret;
+	return 0;
 }
 
 int
-rte_ipsec_sad_del(__rte_unused struct rte_ipsec_sad *sad,
-		__rte_unused const union rte_ipsec_sad_key *key,
-		__rte_unused int key_type)
+rte_ipsec_sad_del(struct rte_ipsec_sad *sad,
+		const union rte_ipsec_sad_key *key,
+		int key_type)
 {
-	return -ENOTSUP;
+	void *tmp_val;
+	int ret;
+
+	if ((sad == NULL) || (key == NULL))
+		return -EINVAL;
+	switch (key_type) {
+	case(RTE_IPSEC_SAD_SPI_ONLY):
+		ret = rte_hash_lookup_data(sad->hash[key_type],
+			key, &tmp_val);
+		if (ret < 0)
+			return ret;
+		if (GET_BIT(tmp_val, RTE_IPSEC_SAD_KEY_TYPE_MASK) == 0) {
+			ret = rte_hash_del_key(sad->hash[key_type],
+				key);
+			ret = ret < 0 ? ret : 0;
+		} else {
+			tmp_val = GET_BIT(tmp_val,
+				RTE_IPSEC_SAD_KEY_TYPE_MASK);
+			ret = rte_hash_add_key_data(sad->hash[key_type],
+				key, tmp_val);
+		}
+		return ret;
+	case(RTE_IPSEC_SAD_SPI_DIP):
+	case(RTE_IPSEC_SAD_SPI_DIP_SIP):
+		return del_specific(sad, key, key_type);
+	default:
+		return -EINVAL;
+	}
 }
 
 struct rte_ipsec_sad *
@@ -252,10 +414,102 @@ rte_ipsec_sad_destroy(struct rte_ipsec_sad *sad)
 		rte_free(te);
 }
 
+/*
+ * @internal helper function
+ * Lookup a batch of keys in three hash tables.
+ * First lookup key in SPI_ONLY table.
+ * If there is an entry for the corresponding SPI check its value.
+ * Two least significant bits of the value indicate
+ * the presence of more specific rule in other tables.
+ * Perform additional lookup in corresponding hash tables
+ * and update the value if lookup succeeded.
+ */
+static int
+__ipsec_sad_lookup(const struct rte_ipsec_sad *sad,
+		const union rte_ipsec_sad_key *keys[], void *sa[], uint32_t n)
+{
+	const void *keys_2[RTE_HASH_LOOKUP_BULK_MAX];
+	const void *keys_3[RTE_HASH_LOOKUP_BULK_MAX];
+	void *vals_2[RTE_HASH_LOOKUP_BULK_MAX] = {NULL};
+	void *vals_3[RTE_HASH_LOOKUP_BULK_MAX] = {NULL};
+	uint32_t idx_2[RTE_HASH_LOOKUP_BULK_MAX];
+	uint32_t idx_3[RTE_HASH_LOOKUP_BULK_MAX];
+	uint64_t mask_1, mask_2, mask_3;
+	uint64_t map, map_spec;
+	uint32_t n_2 = 0;
+	uint32_t n_3 = 0;
+	uint32_t i;
+	int found = 0;
+
+	for (i = 0; i < n; i++)
+		sa[i] = NULL;
+
+	/*
+	 * Lookup keys in SPI only hash table first.
+	 */
+	rte_hash_lookup_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
+		(const void **)keys, n, &mask_1, sa);
+	for (map = mask_1; map; map &= (map - 1)) {
+		i = rte_bsf64(map);
+		/*
+		 * if returned value indicates presence of a rule in other
+		 * tables save a key for further lookup.
+		 */
+		if ((uintptr_t)sa[i] & RTE_IPSEC_SAD_SPI_DIP_SIP) {
+			idx_3[n_3] = i;
+			keys_3[n_3++] = keys[i];
+		}
+		if ((uintptr_t)sa[i] & RTE_IPSEC_SAD_SPI_DIP) {
+			idx_2[n_2] = i;
+			keys_2[n_2++] = keys[i];
+		}
+		/* clear 2 LSB's which indicate the presence
+		 * of more specific rules
+		 */
+		sa[i] = CLEAR_BIT(sa[i], RTE_IPSEC_SAD_KEY_TYPE_MASK);
+	}
+
+	/* Lookup for more specific rules in SPI_DIP table */
+	if (n_2 != 0) {
+		rte_hash_lookup_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_DIP],
+			keys_2, n_2, &mask_2, vals_2);
+		for (map_spec = mask_2; map_spec; map_spec &= (map_spec - 1)) {
+			i = rte_bsf64(map_spec);
+			sa[idx_2[i]] = vals_2[i];
+		}
+	}
+	/* Lookup for more specific rules in SPI_DIP_SIP table */
+	if (n_3 != 0) {
+		rte_hash_lookup_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_DIP_SIP],
+			keys_3, n_3, &mask_3, vals_3);
+		for (map_spec = mask_3; map_spec; map_spec &= (map_spec - 1)) {
+			i = rte_bsf64(map_spec);
+			sa[idx_3[i]] = vals_3[i];
+		}
+	}
+
+	for (i = 0; i < n; i++)
+		found += (sa[i] != NULL);
+
+	return found;
+}
+
 int
-rte_ipsec_sad_lookup(__rte_unused const struct rte_ipsec_sad *sad,
-		__rte_unused const union rte_ipsec_sad_key *keys[],
-		__rte_unused void *sa[], __rte_unused uint32_t n)
+rte_ipsec_sad_lookup(const struct rte_ipsec_sad *sad,
+		const union rte_ipsec_sad_key *keys[], void *sa[], uint32_t n)
 {
-	return -ENOTSUP;
+	uint32_t num, i = 0;
+	int found = 0;
+
+	if (unlikely((sad == NULL) || (keys == NULL) || (sa == NULL)))
+		return -EINVAL;
+
+	do {
+		num = RTE_MIN(n - i, (uint32_t)RTE_HASH_LOOKUP_BULK_MAX);
+		found += __ipsec_sad_lookup(sad,
+			&keys[i], &sa[i], num);
+		i += num;
+	} while (i != n);
+
+	return found;
 }
-- 
2.7.4