cleanups, whitespace fixes, some extra data structures, eol fix
[project/uci.git] / parse.c
1 /*
2 * libuci - Library for the Unified Configuration Interface
3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
4 *
5 * this program is free software; you can redistribute it and/or modify
6 * it under the terms of the gnu lesser general public license version 2.1
7 * as published by the free software foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15 /*
16 * This file contains the code for parsing uci config files
17 */
18
19 #include <ctype.h>
20
21 #define LINEBUF 128
22 #define LINEBUF_MAX 4096
23
24 /*
25 * Fetch a new line from the input stream and resize buffer if necessary
26 */
27 static void uci_getln(struct uci_context *ctx)
28 {
29 struct uci_parse_context *pctx = ctx->pctx;
30 char *p;
31 int ofs;
32
33 if (pctx->buf == NULL) {
34 pctx->buf = uci_malloc(ctx, LINEBUF);
35 pctx->bufsz = LINEBUF;
36 }
37
38 ofs = 0;
39 do {
40 p = &pctx->buf[ofs];
41 p[ofs] = 0;
42
43 p = fgets(p, pctx->bufsz - ofs, pctx->file);
44 if (!p || !p[ofs])
45 return;
46
47 ofs += strlen(p);
48 if (pctx->buf[ofs - 1] == '\n') {
49 pctx->line++;
50 pctx->buf[ofs - 1] = 0;
51 return;
52 }
53
54 if (pctx->bufsz > LINEBUF_MAX/2) {
55 pctx->byte = LINEBUF_MAX;
56 UCI_THROW(ctx, UCI_ERR_PARSE);
57 }
58
59 pctx->bufsz *= 2;
60 pctx->buf = uci_realloc(ctx, pctx->buf, pctx->bufsz);
61 } while (1);
62 }
63
64 /*
65 * Clean up all extra memory used by the parser
66 */
67 static void uci_parse_cleanup(struct uci_context *ctx)
68 {
69 struct uci_parse_context *pctx;
70
71 pctx = ctx->pctx;
72 if (!pctx)
73 return;
74
75 if (pctx->buf)
76 free(pctx->buf);
77 if (pctx->file)
78 fclose(pctx->file);
79
80 free(pctx);
81 }
82
83 /*
84 * move the string pointer forward until a non-whitespace character or
85 * EOL is reached
86 */
87 static void skip_whitespace(char **str)
88 {
89 while (**str && isspace(**str))
90 *str += 1;
91 }
92
93 /*
94 * parse a double quoted string argument from the command line
95 */
96 static char *parse_double_quote(char **str)
97 {
98 char *val;
99
100 *str += 1;
101 val = *str;
102 while (**str) {
103
104 /* skip escaped characters */
105 if (**str == '\\') {
106 *str += 2;
107 continue;
108 }
109
110 /* check for the end of the quoted string */
111 if (**str == '"') {
112 **str = 0;
113 *str += 1;
114 return val;
115 }
116 *str += 1;
117 }
118
119 return NULL;
120 }
121
122 /*
123 * parse a single quoted string argument from the command line
124 */
125 static char *parse_single_quote(char **str)
126 {
127 /* TODO: implement */
128 return NULL;
129 }
130
131 /*
132 * extract the next word from the command line (unquoted argument)
133 */
134 static char *parse_unquoted(char **str)
135 {
136 char *val;
137
138 val = *str;
139
140 while (**str && !isspace(**str))
141 *str += 1;
142
143 if (**str) {
144 **str = 0;
145 *str += 1;
146 }
147
148 return val;
149 }
150
151 /*
152 * extract the next argument from the command line
153 */
154 static char *next_arg(struct uci_context *ctx, char **str, bool required)
155 {
156 char *val;
157
158 skip_whitespace(str);
159 switch (**str) {
160 case '"':
161 val = parse_double_quote(str);
162 case '\'':
163 val = parse_single_quote(str);
164 case 0:
165 val = NULL;
166 default:
167 val = parse_unquoted(str);
168 }
169
170 if (required && !val) {
171 ctx->pctx->byte = *str - ctx->pctx->buf;
172 UCI_THROW(ctx, UCI_ERR_PARSE);
173 }
174
175 return val;
176 }
177
178 /*
179 * verify that the end of the line or command is reached.
180 * throw an error if extra arguments are given on the command line
181 */
182 static void assert_eol(struct uci_context *ctx, char **str)
183 {
184 char *tmp;
185
186 tmp = next_arg(ctx, str, false);
187 if (tmp && *tmp) {
188 ctx->pctx->byte = tmp - ctx->pctx->buf;
189 UCI_THROW(ctx, UCI_ERR_PARSE);
190 }
191 }
192
193 /*
194 * parse the 'config' uci command (open a section)
195 */
196 static void uci_parse_config(struct uci_context *ctx, char **str)
197 {
198 char *type, *name;
199
200 *str += strlen(*str) + 1;
201
202 if (!*str) {
203 ctx->pctx->byte = *str - ctx->pctx->buf;
204 UCI_THROW(ctx, UCI_ERR_PARSE);
205 }
206
207 type = next_arg(ctx, str, true);
208 name = next_arg(ctx, str, false);
209 assert_eol(ctx, str);
210
211 DPRINTF("Section<%s>: %s\n", type, name);
212 }
213
214 /*
215 * parse the 'option' uci command (open a value)
216 */
217 static void uci_parse_option(struct uci_context *ctx, char **str)
218 {
219 char *name, *value;
220
221 *str += strlen(*str) + 1;
222
223 name = next_arg(ctx, str, true);
224 value = next_arg(ctx, str, true);
225 assert_eol(ctx, str);
226
227 DPRINTF("\tOption: %s=\"%s\"\n", name, value);
228 }
229
230 /*
231 * parse a complete input line, split up combined commands by ';'
232 */
233 static void uci_parse_line(struct uci_context *ctx)
234 {
235 struct uci_parse_context *pctx = ctx->pctx;
236 char *word, *brk;
237
238 for (word = strtok_r(pctx->buf, ";", &brk);
239 word;
240 word = strtok_r(NULL, ";", &brk)) {
241
242 char *pbrk;
243 word = strtok_r(word, " \t", &pbrk);
244
245 switch(word[0]) {
246 case 'c':
247 if ((word[1] == 0) || !strcmp(word + 1, "onfig"))
248 uci_parse_config(ctx, &word);
249 break;
250 case 'o':
251 if ((word[1] == 0) || !strcmp(word + 1, "ption"))
252 uci_parse_option(ctx, &word);
253 break;
254 default:
255 pctx->byte = word - pctx->buf;
256 UCI_THROW(ctx, UCI_ERR_PARSE);
257 break;
258 }
259 }
260 }
261
262 int uci_parse(struct uci_context *ctx, const char *name)
263 {
264 struct uci_parse_context *pctx;
265
266 UCI_HANDLE_ERR(ctx);
267 UCI_ASSERT(ctx, name != NULL);
268
269 /* make sure no memory from previous parse attempts is leaked */
270 uci_parse_cleanup(ctx);
271
272 pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
273 ctx->pctx = pctx;
274
275 /* TODO: use /etc/config/ */
276 pctx->file = fopen(name, "r");
277 if (!pctx->file)
278 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
279
280 while (!feof(pctx->file)) {
281 uci_getln(ctx);
282 if (*(pctx->buf))
283 uci_parse_line(ctx);
284 }
285
286 /* if no error happened, we can get rid of the parser context now */
287 uci_parse_cleanup(ctx);
288
289 return 0;
290 }
291
292