lib/command_match.h

   1 /*
   2  * Input matching routines for CLI backend.
   3  *
   4  * --
   5  * Copyright (C) 2016 Cumulus Networks, Inc.
   6  *
   7  * This file is part of GNU Zebra.
   8  *
   9  * GNU Zebra is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the
  11  * Free Software Foundation; either version 2, or (at your option) any
  12  * later version.
  13  *
  14  * GNU Zebra is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  21  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  22  * 02111-1307, USA.
  23  */
  24
  25 #ifndef _ZEBRA_COMMAND_MATCH_H
  26 #define _ZEBRA_COMMAND_MATCH_H
  27
  28 #include "graph.h"
  29 #include "linklist.h"
  30 #include "command.h"
  31
  32 /* These definitions exist in command.c in the current engine but should be
  33  * relocated here in the new engine
  34  */
  35 enum filter_type
  36 {
  37   FILTER_RELAXED,
  38   FILTER_STRICT
  39 };
  40
  41 /* matcher result value */
  42 enum matcher_rv
  43 {
  44   MATCHER_NO_MATCH,
  45   MATCHER_INCOMPLETE,
  46   MATCHER_AMBIGUOUS,
  47   MATCHER_OK,
  48 };
  49
  50 /* completion match types */
  51 enum match_type
  52 {
  53   trivial_match,  // the input is null
  54   no_match,       // the input does not match
  55   partly_match,   // the input matches but is incomplete
  56   exact_match     // the input matches and is complete
  57 };
  58
  59 /* Defines which matcher_rv values constitute an error. Should be used with
  60  * matcher_rv return values to do basic error checking.
  61  */
  62 #define MATCHER_ERROR(matcher_rv) \
  63   (   (matcher_rv) == MATCHER_INCOMPLETE \
  64    || (matcher_rv) == MATCHER_NO_MATCH \
  65    || (matcher_rv) == MATCHER_AMBIGUOUS \
  66   )
  67
  68 /**
  69  * Attempt to find an exact command match for a line of user input.
  70  *
  71  * @param[in] cmdgraph command graph to match against
  72  * @param[in] vline vectorized input string
  73  * @param[out] argv pointer to argument list if successful match, NULL
  74  * otherwise. The elements of this list are pointers to struct cmd_token
  75  * and represent the sequence of tokens matched by the inpu. The ->arg
  76  * field of each token points to a copy of the input matched on it. These
  77  * may be safely deleted or modified.
  78  * @param[out] element pointer to matched cmd_element if successful match,
  79  * or NULL when MATCHER_ERROR(rv) is true. The cmd_element may *not* be
  80  * safely deleted or modified; it is the instance initialized on startup.
  81  * @return matcher status
  82  */
  83 enum matcher_rv
  84 command_match (struct graph *cmdgraph,
  85                vector vline,
  86                struct list **argv,
  87                const struct cmd_element **element);
  88
  89 /**
  90  * Compiles possible completions for a given line of user input.
  91  *
  92  * @param[in] start the start node of the DFA to match against
  93  * @param[in] vline vectorized input string
  94  * @param[out] completions pointer to list of cmd_token representing
  95  * acceptable next inputs, or NULL when MATCHER_ERROR(rv) is true.
  96  * The elements of this list are pointers to struct cmd_token and take on a
  97  * variety of forms depending on the passed vline. If the last element in vline
  98  * is NULL, all previous elements are considered to be complete words (the case
  99  * when a space is the last token of the line) and completions are generated
 100  * based on what could follow that input. If the last element in vline is not
 101  * NULL and each sequential element matches the corresponding tokens of one or
 102  * more commands exactly (e.g. 'encapv4' and not 'en') the same result is
 103  * generated. If the last element is not NULL and the best possible match is a
 104  * partial match, then the result generated will be all possible continuations
 105  * of that element (e.g. 'encapv4', 'encapv6', etc for input 'en').
 106  * @return matcher status
 107  */
 108 enum matcher_rv
 109 command_complete (struct graph *cmdgraph,
 110                   vector vline,
 111                   struct list **completions);
 112
 113 #endif /* _ZEBRA_COMMAND_MATCH_H */