1 /*
2  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
3  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <stdio.h>
19 #include <string.h>
20 
21 #include "ctl_parser.h"
22 #include "kamid.h"
23 
24 enum token_type {
25 	NOTOKEN,
26 	ENDTOKEN,
27 	KEYWORD,
28 };
29 
30 
31 struct token {
32 	enum token_type		 type;
33 	const char		*keyword;
34 	int			 value;
35 	const struct token	*next;
36 };
37 
38 static const struct token t_main[];
39 static const struct token t_log[];
40 
41 static const struct token t_main[] = {
42 	{KEYWORD,	"reload",	RELOAD,		NULL},
43 	{KEYWORD,	"log",		NONE,		t_log},
44 	{ENDTOKEN,	"",		NONE,		NULL},
45 };
46 
47 static const struct token t_log[] = {
48 	{KEYWORD,	"verbose",	LOG_VERBOSE,	NULL},
49 	{KEYWORD,	"brief",	LOG_BRIEF,	NULL},
50 	{ENDTOKEN,	"",		NONE,		NULL},
51 };
52 
53 static const struct token *match_token(const char *, const struct token *,
54     struct parse_result *);
55 static void show_valid_args(const struct token *);
56 
57 struct parse_result *
58 parse(int argc, char **argv)
59 {
60 	static struct parse_result	 res;
61 	const struct token		*table = t_main;
62 	const struct token		*match;
63 
64 	memset(&res, 0, sizeof(res));
65 
66 	while (argc >= 0) {
67 		if ((match = match_token(argv[0], table, &res)) == NULL) {
68 			fprintf(stderr, "valid commands/args:\n");
69 			show_valid_args(table);
70 			return NULL;
71 		}
72 
73 		argc--;
74 		argv++;
75 
76 		if (match->type == NOTOKEN || match->next == NULL)
77 			break;
78 
79 		table = match->next;
80 	}
81 
82 	if (argc > 0) {
83 		fprintf(stderr, "superfluous argument: %s\n", argv[0]);
84 		return NULL;
85 	}
86 
87 	return &res;
88 }
89 
90 static const struct token *
91 match_token(const char *word, const struct token *table,
92     struct parse_result *res)
93 {
94 	size_t			 i, match;
95 	const struct token	*t = NULL;
96 
97 	match = 0;
98 
99 	for (i = 0; table[i].type != ENDTOKEN; i++) {
100 		switch (table[i].type) {
101 		case NOTOKEN:
102 			if (word == NULL || strlen(word) == 0) {
103 				match++;
104 				t = &table[i];
105 			}
106 			break;
107 		case KEYWORD:
108 			if (word != NULL && strncmp(word, table[i].keyword,
109 			    strlen(word)) == 0) {
110 				match++;
111 				t = &table[i];
112 				if (t->value)
113 					res->action = t->value;
114 			}
115 			break;
116 		case ENDTOKEN:
117 			break;
118 		}
119 	}
120 
121 	if (match != 1) {
122 		if (word == NULL)
123 			fprintf(stderr, "missing argument:\n");
124 		else if (match > 1)
125 			fprintf(stderr, "ambiuous argument: %s\n", word);
126 		else if (match < 1)
127 			fprintf(stderr, "unknown argument: %s\n", word);
128 		return NULL;
129 	}
130 
131 	return t;
132 }
133 
134 static void
135 show_valid_args(const struct token *table)
136 {
137 	int i;
138 
139 	for (i = 0; table[i].type != ENDTOKEN; i++) {
140 		switch (table[i].type) {
141 		case NOTOKEN:
142 			fprintf(stderr, "  <cr>\n");
143 			break;
144 		case KEYWORD:
145 			fprintf(stderr, "  %s\n", table[i].keyword);
146 			break;
147 		case ENDTOKEN:
148 			break;
149 		}
150 	}
151 }