This commit adds a flow graph parsing API. This is a helper API intended to help ethdev drivers implement rte_flow parsers, as common usages map to graph traversal problem very well.
Features provided by the API: - Flow graph, edge, and node definitions - Graph traversal logic - Declarative validation against common flow item types - Per-node validation and state processing callbacks Signed-off-by: Anatoly Burakov <[email protected]> --- Depends-on: series-37663 ("Add common flow attr/action parsing infrastructure to Intel PMD's") Depends-on: series-37585 ("Reduce reliance on global response buffer in IAVF") lib/ethdev/meson.build | 1 + lib/ethdev/rte_flow_graph.h | 414 ++++++++++++++++++++++++++++++++++++ 2 files changed, 415 insertions(+) create mode 100644 lib/ethdev/rte_flow_graph.h diff --git a/lib/ethdev/meson.build b/lib/ethdev/meson.build index 8ba6c708a2..686b64e3c2 100644 --- a/lib/ethdev/meson.build +++ b/lib/ethdev/meson.build @@ -40,6 +40,7 @@ driver_sdk_headers += files( 'ethdev_pci.h', 'ethdev_vdev.h', 'rte_flow_driver.h', + 'rte_flow_graph.h', 'rte_mtr_driver.h', 'rte_tm_driver.h', ) diff --git a/lib/ethdev/rte_flow_graph.h b/lib/ethdev/rte_flow_graph.h new file mode 100644 index 0000000000..07c370b45a --- /dev/null +++ b/lib/ethdev/rte_flow_graph.h @@ -0,0 +1,414 @@ +/* SPDX-License-Identifier: BSD-3-Clause + * Copyright(c) 2025 Intel Corporation + */ + +#ifndef _RTE_FLOW_GRAPH_H_ +#define _RTE_FLOW_GRAPH_H_ + +/** + * @file + * RTE Flow Graph Parser (Internal Driver API) + * + * This file provides a graph-based flow pattern parser for PMD drivers. + * It defines structures and functions to validate and process rte_flow + * patterns using a directed graph representation. + * + * @warning + * This is an internal API for PMD drivers only. Applications must not use it. + */ + +#include <rte_flow.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#define RTE_FLOW_NODE_FIRST (0) +/* Edge array termination sentinel (not a valid node index). */ +#define RTE_FLOW_NODE_EDGE_END ((size_t)~0U) + +/** + * For a lot of nodes, there are multiple common patterns of validation behavior. This enum allows + * marking nodes as implementing one of these common behaviors without need for expressing that in + * validation code. Can be ORed together to express support for multiple node types. These checks + * are not combined (any one of them being satisfied is sufficient). + */ +enum rte_flow_graph_node_expect +{ + RTE_FLOW_NODE_EXPECT_NONE = 0, /**< No special constraints. */ + RTE_FLOW_NODE_EXPECT_EMPTY = (1 << 0), /**< spec, mask, last must be NULL. */ + RTE_FLOW_NODE_EXPECT_SPEC = (1 << 1), /**< spec is required, mask and last must be NULL. */ + RTE_FLOW_NODE_EXPECT_MASK = (1 << 2), /**< mask is required, spec and last must be NULL. */ + RTE_FLOW_NODE_EXPECT_SPEC_MASK = (1 << 3), /**< spec and mask required, last must be NULL. */ + RTE_FLOW_NODE_EXPECT_RANGE = (1 << 4), /**< spec, mask, and last are required. */ + RTE_FLOW_NODE_EXPECT_NOT_RANGE = (1 << 5), /**< last must be NULL. */ +}; + +/** + * Node validation callback. + * + * Called when the graph traversal reaches this node. Validates the + * rte_flow_item (spec, mask, last) against driver-specific constraints. + * + * Drivers are suggested to perform all checks in this callback. + * + * @param ctx + * Opaque driver context for accumulating parsed state. + * @param item + * Pointer to the rte_flow_item being validated. + * @param error + * Pointer to rte_flow_error structure for reporting failures. + * @return + * 0 on success, negative errno on failure. + */ +typedef int (*rte_flow_node_validate_fn)( + const void *ctx, + const struct rte_flow_item *item, + struct rte_flow_error *error); + +/** + * Node processing callback. + * + * Called after validation succeeds. Extracts fields from the rte_flow_item + * and stores them in driver-specific state for later hardware programming. + * + * Drivers are suggested to implement "happy path" in this callback. + * + * @param ctx + * Opaque driver context for accumulating parsed state. + * @param item + * Pointer to the rte_flow_item to process. + * @param error + * Pointer to rte_flow_error structure for reporting failures. + * @return + * 0 on success, negative errno on failure. + */ +typedef int (*rte_flow_node_process_fn)( + void *ctx, + const struct rte_flow_item *item, + struct rte_flow_error *error); + +/** + * Graph node definition. + * + * When all members are NULL, it is assumed that the node is not used. + */ +struct rte_flow_graph_node { + const char *name; /**< Node name. */ + const enum rte_flow_item_type type; /**< Corresponding rte_flow_item_type. */ + const enum rte_flow_graph_node_expect constraints; /**< Common validation constraints (ORed). */ + rte_flow_node_validate_fn validate; /**< Validation callback (NULL if unsupported). */ + rte_flow_node_process_fn process; /**< Processing callback (NULL if no extraction needed). */ +}; + +/** + * Graph edge definition. + * + * Describes allowed transitions from one node to others. The 'next' array + * lists all valid successor node types and is terminated by RTE_FLOW_EDGE_END. + * Drivers define edges to express their supported protocol sequences. + */ +struct rte_flow_graph_edge { + const size_t *next; /**< Array of valid successor nodes, terminated by RTE_FLOW_EDGE_END. */ +}; + +/** + * Flow graph to be implemented by drivers. + */ +struct rte_flow_graph { + struct rte_flow_graph_node *nodes; + struct rte_flow_graph_edge *edges; + const enum rte_flow_item_type *ignore_nodes; /**< Additional node types to ignore, terminated by RTE_FLOW_ITEM_TYPE_END. */ +}; + +static inline bool +__flow_graph_node_check_constraint(enum rte_flow_graph_node_expect c, + bool has_spec, bool has_mask, bool has_last) +{ + bool empty = !has_spec && !has_mask && !has_last; + + if ((c & RTE_FLOW_NODE_EXPECT_EMPTY) && empty) + return true; + if ((c & RTE_FLOW_NODE_EXPECT_NOT_RANGE) && !has_last) + return true; + if ((c & RTE_FLOW_NODE_EXPECT_SPEC) && has_spec && !has_mask && !has_last) + return true; + if ((c & RTE_FLOW_NODE_EXPECT_MASK) && has_mask && !has_spec && !has_last) + return true; + if ((c & RTE_FLOW_NODE_EXPECT_SPEC_MASK) && has_spec && has_mask && !has_last) + return true; + if ((c & RTE_FLOW_NODE_EXPECT_RANGE) && has_mask && has_spec && has_last) + return true; + + return false; +} + +static inline bool +__flow_graph_node_is_expected(const struct rte_flow_graph_node *node, + const struct rte_flow_item *item, struct rte_flow_error *error) +{ + enum rte_flow_graph_node_expect c = node->constraints; + + if (c == RTE_FLOW_NODE_EXPECT_NONE) + return true; + + bool has_spec = (item->spec != NULL); + bool has_mask = (item->mask != NULL); + bool has_last = (item->last != NULL); + + if (__flow_graph_node_check_constraint(c, has_spec, has_mask, has_last)) + return true; + + /* + * In the interest of everyone debugging flow parsing code, we should provide the user with + * meaningful messages about exactly what failed, as no one likes non-descript "node + * constraints not met" errors with no clear indication of where this is even coming from. + * What follows is us building said meaningful error messages. It's a bit ugly, but it is + * for the greater good. + */ + const char *msg; + + /* for empty items, we know exactly what went wrong */ + if (c == RTE_FLOW_NODE_EXPECT_EMPTY) { + if (has_spec) + msg = "Unexpected spec in flow item"; + else if (has_mask) + msg = "Unexpected mask in flow item"; + else /* has_last */ + msg = "Unexpected last in flow item"; + } else { + /* + * for non-empty constraints, we need to figure out the one thing user is missing + * (or has extra) that would've satisfied the constraints. + * We do that by flipping each presence bit in turn and seeing whether that single + * change would have satisfied the node constraints. + */ + + /* check spec first */ + if (!has_spec && __flow_graph_node_check_constraint(c, true, has_mask, has_last)) { + msg = "Missing spec in flow item"; + } else if (has_spec && __flow_graph_node_check_constraint(c, false, has_mask, has_last)) { + msg = "Unexpected spec in flow item"; + } + /* check mask next */ + else if (!has_mask && __flow_graph_node_check_constraint(c, has_spec, true, has_last)) { + msg = "Missing mask in flow item"; + } else if (has_mask && __flow_graph_node_check_constraint(c, has_spec, false, has_last)) { + msg = "Unexpected mask in flow item"; + } + /* finally, check range */ + else if (!has_last && __flow_graph_node_check_constraint(c, has_spec, has_mask, true)) { + msg = "Missing last in flow item"; + } else if (has_last && __flow_graph_node_check_constraint(c, has_spec, has_mask, false)) { + msg = "Unexpected last in flow item"; + /* multiple things are wrong with the constraint, so just output a generic error */ + } else { + msg = "Flow item does not meet node constraints"; + } + } + + rte_flow_error_set(error, EINVAL, RTE_FLOW_ERROR_TYPE_ITEM, item, msg); + + return false; +} + +/** + * @internal + * Check if a graph node is null/unused. + * + * Valid graph nodes must at least define a name. + */ +__rte_internal +static inline bool +__flow_graph_node_is_null(const struct rte_flow_graph_node *node) +{ + return node->name == NULL && node->type == RTE_FLOW_ITEM_TYPE_END && + node->process == NULL && node->validate == NULL; +} + +/** + * @internal + * Check if a flow item type should be ignored by the graph. + * + * Checks if the item type is in the graph's ignore list. + */ +__rte_internal +static inline bool +__flow_graph_node_is_ignored(const struct rte_flow_graph *graph, + enum rte_flow_item_type fi_type) +{ + const enum rte_flow_item_type *ignored; + + /* Always skip VOID items */ + if (fi_type == RTE_FLOW_ITEM_TYPE_VOID) + return true; + + if (graph->ignore_nodes == NULL) + return false; + + for (ignored = graph->ignore_nodes; *ignored != RTE_FLOW_ITEM_TYPE_END; ignored++) { + if (*ignored == fi_type) + return true; + } + + return false; +} + +/** + * @internal + * Get the index of a node within a graph. + */ +__rte_internal +static inline size_t +__flow_graph_get_node_index(const struct rte_flow_graph *graph, const struct rte_flow_graph_node *node) +{ + return (size_t)(node - graph->nodes); +} + +/** + * @internal + * Find the next node in the graph matching the given item type. + */ +__rte_internal +static inline const struct rte_flow_graph_node * +__flow_graph_find_next_node(const struct rte_flow_graph *graph, + const struct rte_flow_graph_node *cur_node, + enum rte_flow_item_type next_type) +{ + const size_t *next_nodes; + size_t cur_idx, edge_idx; + + cur_idx = __flow_graph_get_node_index(graph, cur_node); + next_nodes = graph->edges[cur_idx].next; + if (next_nodes == NULL) + return NULL; + + for (edge_idx = 0; next_nodes[edge_idx] != RTE_FLOW_NODE_EDGE_END; edge_idx++) { + const struct rte_flow_graph_node *tmp = + &graph->nodes[next_nodes[edge_idx]]; + if (__flow_graph_node_is_null(tmp)) + continue; + if (tmp->type == next_type) + return tmp; + } + + return NULL; +} + +/** + * @internal + * Visit (validate and extract) a node's item. + */ +__rte_internal +static inline int +__flow_graph_visit_node(const struct rte_flow_graph_node *node, void *ctx, + const struct rte_flow_item *item, struct rte_flow_error *error) +{ + int ret; + + /* if we expect a certain type of node, check for it */ + if (!__flow_graph_node_is_expected(node, item, error)) + /* error already set */ + return -1; + + /* Does this node fit driver's criteria? */ + if (node->validate != NULL) { + ret = node->validate(ctx, item, error); + if (ret != 0) + return ret; + } + + /* Extract data from this item */ + if (node->process != NULL) { + ret = node->process(ctx, item, error); + if (ret != 0) + return ret; + } + + return 0; +} + +/** + * @internal + * Parse and validate a flow pattern using the flow graph. + * + * Traverses the pattern items and validates them against the driver's graph + * structure. For each item, checks that the transition from the current node + * is allowed, then invokes validation and processing callbacks. + * + * @param graph + * Pointer to the driver's flow graph definition with nodes and edges. + * @param pattern + * Array of rte_flow_item structures to parse, terminated by RTE_FLOW_ITEM_TYPE_END. + * @param error + * Pointer to rte_flow_error structure for reporting failures. + * @param ctx + * Opaque driver context for accumulating parsed state. + * @return + * 0 on success, negative errno on failure (error is set). + */ +__rte_internal +static inline int +rte_flow_graph_parse(const struct rte_flow_graph *graph, const struct rte_flow_item *pattern, + struct rte_flow_error *error, void *ctx) +{ + const struct rte_flow_graph_node *cur_node; + const struct rte_flow_item *item; + int ret; + + if (graph == NULL || graph->nodes == NULL || graph->edges == NULL) { + return rte_flow_error_set(error, ENOTSUP, + RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL, + "Flow graph is not defined"); + } + if (pattern == NULL) { + return rte_flow_error_set(error, EINVAL, + RTE_FLOW_ERROR_TYPE_ITEM, NULL, + "Flow pattern is NULL"); + } + + /* process start node */ + cur_node = &graph->nodes[RTE_FLOW_NODE_FIRST]; + ret = __flow_graph_visit_node(cur_node, ctx, NULL, error); + if (ret != 0) + return ret; + + /* Traverse pattern items */ + for (item = pattern; item->type != RTE_FLOW_ITEM_TYPE_END; item++) { + + /* Skip items in the graph's ignore list */ + if (__flow_graph_node_is_ignored(graph, item->type)) + continue; + + /* Find the next graph node for this item type */ + cur_node = __flow_graph_find_next_node(graph, cur_node, item->type); + if (cur_node == NULL) { + return rte_flow_error_set(error, ENOTSUP, + RTE_FLOW_ERROR_TYPE_ITEM, + item, "Pattern item not supported"); + } + /* Validate and process the current item at this node */ + ret = __flow_graph_visit_node(cur_node, ctx, item, error); + if (ret != 0) + return ret; + } + + /* Pattern items have ended but we still need to process the end */ + cur_node = __flow_graph_find_next_node(graph, cur_node, RTE_FLOW_ITEM_TYPE_END); + if (cur_node == NULL) { + return rte_flow_error_set(error, ENOTSUP, + RTE_FLOW_ERROR_TYPE_ITEM, + item, "Pattern item not supported"); + } + ret = __flow_graph_visit_node(cur_node, ctx, item, error); + if (ret != 0) + return ret; + + return 0; +} + +#ifdef __cplusplus +} +#endif + +#endif /* _RTE_FLOW_GRAPH_H_ */ -- 2.47.3
