Fix delta path handling.
[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 #include <libgen.h>
31
32 #include "uci.h"
33 #include "uci_internal.h"
34
35 __private void *uci_malloc(struct uci_context *ctx, size_t size)
36 {
37 void *ptr;
38
39 ptr = malloc(size);
40 if (!ptr)
41 UCI_THROW(ctx, UCI_ERR_MEM);
42 memset(ptr, 0, size);
43
44 return ptr;
45 }
46
47 __private void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size)
48 {
49 ptr = realloc(ptr, size);
50 if (!ptr)
51 UCI_THROW(ctx, UCI_ERR_MEM);
52
53 return ptr;
54 }
55
56 __private char *uci_strdup(struct uci_context *ctx, const char *str)
57 {
58 char *ptr;
59
60 ptr = strdup(str);
61 if (!ptr)
62 UCI_THROW(ctx, UCI_ERR_MEM);
63
64 return ptr;
65 }
66
67 /*
68 * validate strings for names and types, reject special characters
69 * for names, only alphanum and _ is allowed (shell compatibility)
70 * for types, we allow more characters
71 */
72 __private bool uci_validate_str(const char *str, bool name, bool package)
73 {
74 if (!*str)
75 return false;
76
77 for (; *str; str++) {
78 unsigned char c = *str;
79
80 if (isalnum(c) || c == '_')
81 continue;
82
83 if (c == '-' && package)
84 continue;
85
86 if (name || (c < 33) || (c > 126))
87 return false;
88 }
89 return true;
90 }
91
92 bool uci_validate_text(const char *str)
93 {
94 while (*str) {
95 unsigned char c = *str;
96
97 if (c < 32 && c != '\t' && c != '\n' && c != '\r')
98 return false;
99
100 str++;
101 }
102 return true;
103 }
104
105 __private void uci_alloc_parse_context(struct uci_context *ctx)
106 {
107 ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
108 }
109
110 int uci_parse_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str)
111 {
112 char *last = NULL;
113 char *tmp;
114
115 UCI_HANDLE_ERR(ctx);
116 UCI_ASSERT(ctx, str);
117 UCI_ASSERT(ctx, ptr);
118
119 memset(ptr, 0, sizeof(struct uci_ptr));
120
121 /* value */
122 last = strchr(str, '=');
123 if (last) {
124 *last = 0;
125 last++;
126 ptr->value = last;
127 }
128
129 ptr->package = strsep(&str, ".");
130 if (!ptr->package)
131 goto error;
132
133 ptr->section = strsep(&str, ".");
134 if (!ptr->section) {
135 ptr->target = UCI_TYPE_PACKAGE;
136 goto lastval;
137 }
138
139 ptr->option = strsep(&str, ".");
140 if (!ptr->option) {
141 ptr->target = UCI_TYPE_SECTION;
142 goto lastval;
143 } else {
144 ptr->target = UCI_TYPE_OPTION;
145 }
146
147 tmp = strsep(&str, ".");
148 if (tmp)
149 goto error;
150
151 lastval:
152 if (ptr->package && !uci_validate_package(ptr->package))
153 goto error;
154 if (ptr->section && !uci_validate_name(ptr->section))
155 ptr->flags |= UCI_LOOKUP_EXTENDED;
156 if (ptr->option && !uci_validate_name(ptr->option))
157 goto error;
158 if (ptr->value && !uci_validate_text(ptr->value))
159 goto error;
160
161 return 0;
162
163 error:
164 memset(ptr, 0, sizeof(struct uci_ptr));
165 UCI_THROW(ctx, UCI_ERR_PARSE);
166 }
167
168
169 __private void uci_parse_error(struct uci_context *ctx, char *reason)
170 {
171 struct uci_parse_context *pctx = ctx->pctx;
172
173 pctx->reason = reason;
174 pctx->byte = pctx_pos(pctx);
175 UCI_THROW(ctx, UCI_ERR_PARSE);
176 }
177
178
179
180 /*
181 * open a stream and go to the right position
182 *
183 * note: when opening for write and seeking to the beginning of
184 * the stream, truncate the file
185 */
186 __private FILE *uci_open_stream(struct uci_context *ctx, const char *filename, const char *origfilename, int pos, bool write, bool create)
187 {
188 struct stat statbuf;
189 FILE *file = NULL;
190 int fd, ret;
191 int flags = (write ? O_RDWR : O_RDONLY);
192 mode_t mode = UCI_FILEMODE;
193 char *name = NULL;
194 char *filename2 = NULL;
195
196 if (create) {
197 flags |= O_CREAT;
198 if (origfilename) {
199 name = basename((char *) origfilename);
200 } else {
201 name = basename((char *) filename);
202 }
203 if ((asprintf(&filename2, "%s/%s", ctx->confdir, name) < 0) || !filename2) {
204 UCI_THROW(ctx, UCI_ERR_MEM);
205 } else {
206 if (stat(filename2, &statbuf) == 0)
207 mode = statbuf.st_mode;
208
209 free(filename2);
210 }
211 }
212
213 if (!write && ((stat(filename, &statbuf) < 0) ||
214 ((statbuf.st_mode & S_IFMT) != S_IFREG))) {
215 UCI_THROW(ctx, UCI_ERR_NOTFOUND);
216 }
217
218 fd = open(filename, flags, mode);
219 if (fd < 0)
220 goto error;
221
222 ret = flock(fd, (write ? LOCK_EX : LOCK_SH));
223 if ((ret < 0) && (errno != ENOSYS))
224 goto error;
225
226 ret = lseek(fd, 0, pos);
227
228 if (ret < 0)
229 goto error;
230
231 file = fdopen(fd, (write ? "w+" : "r"));
232 if (file)
233 goto done;
234
235 error:
236 UCI_THROW(ctx, UCI_ERR_IO);
237 done:
238 return file;
239 }
240
241 __private void uci_close_stream(FILE *stream)
242 {
243 int fd;
244
245 if (!stream)
246 return;
247
248 fflush(stream);
249 fd = fileno(stream);
250 flock(fd, LOCK_UN);
251 fclose(stream);
252 }
253
254