lua: always return after calling luaL_error (patch by Stanislav Fomichev)
[project/uci.git] / util.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 Lesser General Public License for more details.
13 */
14
15 /*
16 * This file contains misc utility functions and wrappers to standard
17 * functions, which throw exceptions upon failure.
18 */
19 #define _GNU_SOURCE
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/file.h>
23 #include <stdbool.h>
24 #include <unistd.h>
25 #include <ctype.h>
26 #include <fcntl.h>
27 #include <errno.h>
28 #include <stdlib.h>
29 #include <string.h>
30
31 #include "uci.h"
32 #include "uci_internal.h"
33
34 __plugin void *uci_malloc(struct uci_context *ctx, size_t size)
35 {
36 void *ptr;
37
38 ptr = malloc(size);
39 if (!ptr)
40 UCI_THROW(ctx, UCI_ERR_MEM);
41 memset(ptr, 0, size);
42
43 return ptr;
44 }
45
46 __plugin void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size)
47 {
48 ptr = realloc(ptr, size);
49 if (!ptr)
50 UCI_THROW(ctx, UCI_ERR_MEM);
51
52 return ptr;
53 }
54
55 __plugin char *uci_strdup(struct uci_context *ctx, const char *str)
56 {
57 char *ptr;
58
59 ptr = strdup(str);
60 if (!ptr)
61 UCI_THROW(ctx, UCI_ERR_MEM);
62
63 return ptr;
64 }
65
66 /*
67 * validate strings for names and types, reject special characters
68 * for names, only alphanum and _ is allowed (shell compatibility)
69 * for types, we allow more characters
70 */
71 __plugin bool uci_validate_str(const char *str, bool name)
72 {
73 if (!*str)
74 return false;
75
76 while (*str) {
77 unsigned char c = *str;
78 if (!isalnum(c) && c != '_') {
79 if (name || (c < 33) || (c > 126))
80 return false;
81 }
82 str++;
83 }
84 return true;
85 }
86
87 bool uci_validate_text(const char *str)
88 {
89 while (*str) {
90 unsigned char c = *str;
91 if ((c == '\r') || (c == '\n') ||
92 ((c < 32) && (c != '\t')))
93 return false;
94 str++;
95 }
96 return true;
97 }
98
99 __private void uci_alloc_parse_context(struct uci_context *ctx)
100 {
101 ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
102 }
103
104 int uci_parse_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str)
105 {
106 char *last = NULL;
107 char *tmp;
108
109 UCI_HANDLE_ERR(ctx);
110 UCI_ASSERT(ctx, str);
111 UCI_ASSERT(ctx, ptr);
112
113 memset(ptr, 0, sizeof(struct uci_ptr));
114
115 /* value */
116 last = strchr(str, '=');
117 if (last) {
118 *last = 0;
119 last++;
120 ptr->value = last;
121 }
122
123 ptr->package = strsep(&str, ".");
124 if (!ptr->package)
125 goto error;
126
127 ptr->section = strsep(&str, ".");
128 if (!ptr->section) {
129 ptr->target = UCI_TYPE_PACKAGE;
130 goto lastval;
131 }
132
133 ptr->option = strsep(&str, ".");
134 if (!ptr->option) {
135 ptr->target = UCI_TYPE_SECTION;
136 goto lastval;
137 } else {
138 ptr->target = UCI_TYPE_OPTION;
139 }
140
141 tmp = strsep(&str, ".");
142 if (tmp)
143 goto error;
144
145 lastval:
146 if (ptr->package && !uci_validate_package(ptr->package))
147 goto error;
148 if (ptr->section && !uci_validate_name(ptr->section))
149 ptr->flags |= UCI_LOOKUP_EXTENDED;
150 if (ptr->option && !uci_validate_name(ptr->option))
151 goto error;
152 if (ptr->value && !uci_validate_text(ptr->value))
153 goto error;
154
155 return 0;
156
157 error:
158 memset(ptr, 0, sizeof(struct uci_ptr));
159 UCI_THROW(ctx, UCI_ERR_PARSE);
160 }
161
162
163 __private void uci_parse_error(struct uci_context *ctx, char *pos, char *reason)
164 {
165 struct uci_parse_context *pctx = ctx->pctx;
166
167 pctx->reason = reason;
168 pctx->byte = pos - pctx->buf;
169 UCI_THROW(ctx, UCI_ERR_PARSE);
170 }
171
172
173
174 /*
175 * open a stream and go to the right position
176 *
177 * note: when opening for write and seeking to the beginning of
178 * the stream, truncate the file
179 */
180 __private FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create)
181 {
182 struct stat statbuf;
183 FILE *file = NULL;
184 int fd, ret;
185 int mode = (write ? O_RDWR : O_RDONLY);
186
187 if (create)
188 mode |= O_CREAT;
189
190 if (!write && ((stat(filename, &statbuf) < 0) ||
191 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
192 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
193 }
194
195 fd = open(filename, mode, UCI_FILEMODE);
196 if (fd < 0)
197 goto error;
198
199 ret = flock(fd, (write ? LOCK_EX : LOCK_SH));
200 if ((ret < 0) && (errno != ENOSYS))
201 goto error;
202
203 ret = lseek(fd, 0, pos);
204
205 if (ret < 0)
206 goto error;
207
208 file = fdopen(fd, (write ? "w+" : "r"));
209 if (file)
210 goto done;
211
212 error:
213 UCI_THROW(ctx, UCI_ERR_IO);
214 done:
215 return file;
216 }
217
218 __private void uci_close_stream(FILE *stream)
219 {
220 int fd;
221
222 if (!stream)
223 return;
224
225 fflush(stream);
226 fd = fileno(stream);
227 flock(fd, LOCK_UN);
228 fclose(stream);
229 }
230
231