xref: /openbsd-src/usr.sbin/unwindctl/parser.c (revision 5e3c7963eb248119b7dfd4b0defad58a7d9cd306)
1 /*	$OpenBSD: parser.c,v 1.2 2019/01/27 12:41:39 florian Exp $	*/
2 
3 /*
4  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
5  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <sys/queue.h>
22 #include <sys/socket.h>
23 #include <netinet/in.h>
24 #include <arpa/inet.h>
25 #include <net/if.h>
26 #include <err.h>
27 #include <errno.h>
28 #include <event.h>
29 #include <imsg.h>
30 #include <limits.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include "unwind.h"
36 #include "parser.h"
37 
38 enum token_type {
39 	NOTOKEN,
40 	ENDTOKEN,
41 	KEYWORD
42 };
43 
44 struct token {
45 	enum token_type		 type;
46 	const char		*keyword;
47 	int			 value;
48 	const struct token	*next;
49 };
50 
51 static const struct token t_main[];
52 static const struct token t_log[];
53 static const struct token t_status[];
54 
55 static const struct token t_main[] = {
56 	{KEYWORD,	"reload",	RELOAD,		NULL},
57 	{KEYWORD,	"status",	STATUS,		t_status},
58 	{KEYWORD,	"log",		NONE,		t_log},
59 	{ENDTOKEN,	"",		NONE,		NULL}
60 };
61 
62 static const struct token t_log[] = {
63 	{KEYWORD,	"debug",	LOG_DEBUG,	NULL},
64 	{KEYWORD,	"verbose",	LOG_VERBOSE,	NULL},
65 	{KEYWORD,	"brief",	LOG_BRIEF,	NULL},
66 	{ENDTOKEN,	"",		NONE,		NULL}
67 };
68 
69 static const struct token t_status[] = {
70 	{NOTOKEN,	"",		NONE,			NULL},
71 	{KEYWORD,	"recursor",	STATUS_RECURSOR,	NULL},
72 	{KEYWORD,	"dhcp",		STATUS_DHCP,		NULL},
73 	{KEYWORD,	"static",	STATUS_STATIC,		NULL},
74 	{KEYWORD,	"DoT",		STATUS_DOT,		NULL},
75 	{ENDTOKEN,	"",		STATUS,			NULL}
76 };
77 
78 static const struct token *match_token(const char *, const struct token *,
79     struct parse_result *);
80 static void show_valid_args(const struct token *);
81 
82 struct parse_result *
83 parse(int argc, char *argv[])
84 {
85 	static struct parse_result	res;
86 	const struct token	*table = t_main;
87 	const struct token	*match;
88 
89 	memset(&res, 0, sizeof(res));
90 
91 	while (argc >= 0) {
92 		if ((match = match_token(argv[0], table, &res)) == NULL) {
93 			fprintf(stderr, "valid commands/args:\n");
94 			show_valid_args(table);
95 			return (NULL);
96 		}
97 
98 		argc--;
99 		argv++;
100 
101 		if (match->type == NOTOKEN || match->next == NULL)
102 			break;
103 
104 		table = match->next;
105 	}
106 
107 	if (argc > 0) {
108 		fprintf(stderr, "superfluous argument: %s\n", argv[0]);
109 		return (NULL);
110 	}
111 
112 	return (&res);
113 }
114 
115 static const struct token *
116 match_token(const char *word, const struct token *table,
117     struct parse_result *res)
118 {
119 	u_int			 i, match;
120 	const struct token	*t = NULL;
121 
122 	match = 0;
123 
124 	for (i = 0; table[i].type != ENDTOKEN; i++) {
125 		switch (table[i].type) {
126 		case NOTOKEN:
127 			if (word == NULL || strlen(word) == 0) {
128 				match++;
129 				t = &table[i];
130 			}
131 			break;
132 		case KEYWORD:
133 			if (word != NULL && strncmp(word, table[i].keyword,
134 			    strlen(word)) == 0) {
135 				match++;
136 				t = &table[i];
137 				if (t->value)
138 					res->action = t->value;
139 			}
140 			break;
141 		case ENDTOKEN:
142 			break;
143 		}
144 	}
145 
146 	if (match != 1) {
147 		if (word == NULL)
148 			fprintf(stderr, "missing argument:\n");
149 		else if (match > 1)
150 			fprintf(stderr, "ambiguous argument: %s\n", word);
151 		else if (match < 1)
152 			fprintf(stderr, "unknown argument: %s\n", word);
153 		return (NULL);
154 	}
155 
156 	return (t);
157 }
158 
159 static void
160 show_valid_args(const struct token *table)
161 {
162 	int	i;
163 
164 	for (i = 0; table[i].type != ENDTOKEN; i++) {
165 		switch (table[i].type) {
166 		case NOTOKEN:
167 			fprintf(stderr, "  <cr>\n");
168 			break;
169 		case KEYWORD:
170 			fprintf(stderr, "  %s\n", table[i].keyword);
171 			break;
172 		case ENDTOKEN:
173 			break;
174 		}
175 	}
176 }
177