lib/command_match.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Input matching routines for CLI backend.
   4  *
   5  * --
   6  * Copyright (C) 2016 Cumulus Networks, Inc.
   7  */
   8
   9 #ifndef _ZEBRA_COMMAND_MATCH_H
  10 #define _ZEBRA_COMMAND_MATCH_H
  11
  12 #include "graph.h"
  13 #include "linklist.h"
  14 #include "command.h"
  15
  16 #ifdef __cplusplus
  17 extern "C" {
  18 #endif
  19
  20 /* These definitions exist in command.c in the current engine but should be
  21  * relocated here in the new engine
  22  */
  23 enum cmd_filter_type { FILTER_RELAXED, FILTER_STRICT };
  24
  25 /* matcher result value */
  26 enum matcher_rv {
  27         MATCHER_NO_MATCH,
  28         MATCHER_INCOMPLETE,
  29         MATCHER_AMBIGUOUS,
  30         MATCHER_OK,
  31 };
  32
  33 /* completion match types */
  34 enum match_type {
  35         trivial_match, // the input is null
  36         no_match,      // the input does not match
  37         partly_match,  // the input matches but is incomplete
  38         exact_match    // the input matches and is complete
  39 };
  40
  41 /* Defines which matcher_rv values constitute an error. Should be used with
  42  * matcher_rv return values to do basic error checking.
  43  */
  44 #define MATCHER_ERROR(matcher_rv)                                              \
  45         ((matcher_rv) == MATCHER_INCOMPLETE                                    \
  46          || (matcher_rv) == MATCHER_NO_MATCH                                   \
  47          || (matcher_rv) == MATCHER_AMBIGUOUS)
  48
  49 /**
  50  * Attempt to find an exact command match for a line of user input.
  51  *
  52  * @param[in] cmdgraph command graph to match against
  53  * @param[in] vline vectorized input string
  54  * @param[out] argv pointer to argument list if successful match, NULL
  55  * otherwise. The elements of this list are pointers to struct cmd_token
  56  * and represent the sequence of tokens matched by the input. The ->arg
  57  * field of each token points to a copy of the input matched on it. These
  58  * may be safely deleted or modified.
  59  * @param[out] element pointer to matched cmd_element if successful match,
  60  * or NULL when MATCHER_ERROR(rv) is true. The cmd_element may *not* be
  61  * safely deleted or modified; it is the instance initialized on startup.
  62  * @return matcher status
  63  */
  64 enum matcher_rv command_match(struct graph *cmdgraph, vector vline,
  65                               struct list **argv,
  66                               const struct cmd_element **element);
  67
  68 /**
  69  * Compiles possible completions for a given line of user input.
  70  *
  71  * @param[in] start the start node of the DFA to match against
  72  * @param[in] vline vectorized input string
  73  * @param[out] completions pointer to list of cmd_token representing
  74  * acceptable next inputs, or NULL when MATCHER_ERROR(rv) is true.
  75  * The elements of this list are pointers to struct cmd_token and take on a
  76  * variety of forms depending on the passed vline. If the last element in vline
  77  * is NULL, all previous elements are considered to be complete words (the case
  78  * when a space is the last token of the line) and completions are generated
  79  * based on what could follow that input. If the last element in vline is not
  80  * NULL and each sequential element matches the corresponding tokens of one or
  81  * more commands exactly (e.g. 'encapv4' and not 'en') the same result is
  82  * generated. If the last element is not NULL and the best possible match is a
  83  * partial match, then the result generated will be all possible continuations
  84  * of that element (e.g. 'encapv4', 'encapv6', etc for input 'en').
  85  * @return matcher status
  86  */
  87 enum matcher_rv command_complete(struct graph *cmdgraph, vector vline,
  88                                  struct list **completions);
  89
  90 #ifdef __cplusplus
  91 }
  92 #endif
  93
  94 #endif /* _ZEBRA_COMMAND_MATCH_H */