NXAST_REG_LOAD, /* struct nx_action_reg_load */
NXAST_NOTE, /* struct nx_action_note */
NXAST_SET_TUNNEL64, /* struct nx_action_set_tunnel64 */
+ NXAST_MULTIPATH /* struct nx_action_multipath */
};
/* Header for Nicira-defined actions. */
};
OFP_ASSERT(sizeof(struct nx_action_note) == 16);
+/* Action structure for NXAST_MULTIPATH.
+ *
+ * This action performs the following steps in sequence:
+ *
+ * 1. Hashes the fields designated by 'fields', one of NX_MP_FIELDS_*.
+ * Refer to the definition of "enum nx_mp_fields" for details.
+ *
+ * The 'basis' value is used as a universal hash parameter, that is,
+ * different values of 'basis' yield different hash functions. The
+ * particular universal hash function used is implementation-defined.
+ *
+ * The hashed fields' values are drawn from the current state of the
+ * flow, including all modifications that have been made by actions up to
+ * this point.
+ *
+ * 2. Applies the multipath link choice algorithm specified by 'algorithm',
+ * one of NX_MP_ALG_*. Refer to the definition of "enum nx_mp_algorithm"
+ * for details.
+ *
+ * The output of the algorithm is 'link', an unsigned integer less than
+ * or equal to 'max_link'.
+ *
+ * Some algorithms use 'arg' as an additional argument.
+ *
+ * 3. Stores 'link' in dst[ofs:ofs+n_bits]. The format and semantics of
+ * 'dst' and 'ofs_nbits' are identical to those for the NXAST_REG_LOAD
+ * action; refer to the description of that action for details.
+ *
+ * The switch will reject actions that have an unknown 'fields', or an unknown
+ * 'algorithm', or in which ofs+n_bits is greater than the width of 'dst', or
+ * in which 'max_link' is greater than or equal to 2**n_bits, with error type
+ * OFPET_BAD_ACTION, code OFPBAC_BAD_ARGUMENT.
+ */
+struct nx_action_multipath {
+ ovs_be16 type; /* OFPAT_VENDOR. */
+ ovs_be16 len; /* Length is 32. */
+ ovs_be32 vendor; /* NX_VENDOR_ID. */
+ ovs_be16 subtype; /* NXAST_MULTIPATH. */
+
+ /* What fields to hash and how. */
+ ovs_be16 fields; /* One of NX_MP_FIELDS_*. */
+ ovs_be16 basis; /* Universal hash parameter. */
+ ovs_be16 pad0;
+
+ /* Multipath link choice algorithm to apply to hash value. */
+ ovs_be16 algorithm; /* One of NX_MP_ALG_*. */
+ ovs_be16 max_link; /* Number of output links, minus 1. */
+ ovs_be32 arg; /* Algorithm-specific argument. */
+ ovs_be16 pad1;
+
+ /* Where to store the result. */
+ ovs_be16 ofs_nbits; /* (ofs << 6) | (n_bits - 1). */
+ ovs_be32 dst; /* Destination register. */
+};
+OFP_ASSERT(sizeof(struct nx_action_multipath) == 32);
+
+/* NXAST_MULTIPATH: Fields to hash. */
+enum nx_mp_fields {
+ /* Ethernet source address (NXM_OF_ETH_SRC) only. */
+ NX_MP_FIELDS_ETH_SRC,
+
+ /* L2 through L4, symmetric across src/dst. Specifically, each of the
+ * following fields, if present, is hashed (slashes separate symmetric
+ * pairs):
+ *
+ * - NXM_OF_ETH_DST / NXM_OF_ETH_SRC
+ * - NXM_OF_ETH_TYPE
+ * - The VID bits from NXM_OF_VLAN_TCI, ignoring PCP and CFI.
+ * - NXM_OF_IP_PROTO
+ * - NXM_OF_IP_SRC / NXM_OF_IP_DST
+ * - NXM_OF_TCP_SRC / NXM_OF_TCP_DST
+ * - NXM_OF_UDP_SRC / NXM_OF_UDP_DST
+ */
+ NX_MP_FIELDS_SYMMETRIC_L4
+};
+
+/* NXAST_MULTIPATH: Multipath link choice algorithm to apply.
+ *
+ * In the descriptions below, 'n_links' is max_link + 1. */
+enum nx_mp_algorithm {
+ /* link = hash(flow) % n_links.
+ *
+ * Redistributes all traffic when n_links changes. O(1) performance. See
+ * RFC 2992.
+ *
+ * Use UINT16_MAX for max_link to get a raw hash value. */
+ NX_MP_ALG_MODULO_N,
+
+ /* link = hash(flow) / (MAX_HASH / n_links).
+ *
+ * Redistributes between one-quarter and one-half of traffic when n_links
+ * changes. O(1) performance. See RFC 2992.
+ */
+ NX_MP_ALG_HASH_THRESHOLD,
+
+ /* for i in [0,n_links):
+ * weights[i] = hash(flow, i)
+ * link = { i such that weights[i] >= weights[j] for all j != i }
+ *
+ * Redistributes 1/n_links of traffic when n_links changes. O(n_links)
+ * performance. If n_links is greater than a threshold (currently 64, but
+ * subject to change), Open vSwitch will substitute another algorithm
+ * automatically. See RFC 2992. */
+ NX_MP_ALG_HRW, /* Highest Random Weight. */
+
+ /* i = 0
+ * repeat:
+ * i = i + 1
+ * link = hash(flow, i) % arg
+ * while link > max_link
+ *
+ * Redistributes 1/n_links of traffic when n_links changes. O(1)
+ * performance when arg/max_link is bounded by a constant.
+ *
+ * Redistributes all traffic when arg changes.
+ *
+ * arg must be greater than max_link and for best performance should be no
+ * more than approximately max_link * 2. If arg is outside the acceptable
+ * range, Open vSwitch will automatically substitute the least power of 2
+ * greater than max_link.
+ *
+ * This algorithm is specific to Open vSwitch.
+ */
+ NX_MP_ALG_ITER_HASH /* Iterative Hash. */
+};
+
/* Wildcard for tunnel ID. */
#define NXFW_TUN_ID (1 << 25)
projects / openvswitch / blobdiff