1 /* flac - Command-line FLAC encoder/decoder
2 * Copyright (C) 2002,2003,2004,2005,2006,2007 Josh Coalson
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
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 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #if HAVE_CONFIG_H
20 # include <config.h>
21 #endif
22
23 #include "vorbiscomment.h"
24 #include "FLAC/assert.h"
25 #include "FLAC/metadata.h"
26 #include "share/grabbag.h" /* for grabbag__file_get_filesize() */
27 #include "share/utf8.h"
28 #include <ctype.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32
33
34 /*
35 * This struct and the following 4 static functions are copied from
36 * ../metaflac/. Maybe someday there will be a convenience
37 * library for Vorbis comment parsing.
38 */
39 typedef struct {
40 char *field; /* the whole field as passed on the command line, i.e. "NAME=VALUE" */
41 char *field_name;
42 /* according to the vorbis spec, field values can contain \0 so simple C strings are not enough here */
43 unsigned field_value_length;
44 char *field_value;
45 FLAC__bool field_value_from_file; /* true if field_value holds a filename for the value, false for plain value */
46 } Argument_VcField;
47
die(const char * message)48 static void die(const char *message)
49 {
50 FLAC__ASSERT(0 != message);
51 fprintf(stderr, "ERROR: %s\n", message);
52 exit(1);
53 }
54
local_strdup(const char * source)55 static char *local_strdup(const char *source)
56 {
57 char *ret;
58 FLAC__ASSERT(0 != source);
59 if(0 == (ret = strdup(source)))
60 die("out of memory during strdup()");
61 return ret;
62 }
63
parse_vorbis_comment_field(const char * field_ref,char ** field,char ** name,char ** value,unsigned * length,const char ** violation)64 static FLAC__bool parse_vorbis_comment_field(const char *field_ref, char **field, char **name, char **value, unsigned *length, const char **violation)
65 {
66 static const char * const violations[] = {
67 "field name contains invalid character",
68 "field contains no '=' character"
69 };
70
71 char *p, *q, *s;
72
73 if(0 != field)
74 *field = local_strdup(field_ref);
75
76 s = local_strdup(field_ref);
77
78 if(0 == (p = strchr(s, '='))) {
79 free(s);
80 *violation = violations[1];
81 return false;
82 }
83 *p++ = '\0';
84
85 for(q = s; *q; q++) {
86 if(*q < 0x20 || *q > 0x7d || *q == 0x3d) {
87 free(s);
88 *violation = violations[0];
89 return false;
90 }
91 }
92
93 *name = local_strdup(s);
94 *value = local_strdup(p);
95 *length = strlen(p);
96
97 free(s);
98 return true;
99 }
100
101 /* slight modification: no 'filename' arg, and errors are passed back in 'violation' instead of printed to stderr */
set_vc_field(FLAC__StreamMetadata * block,const Argument_VcField * field,FLAC__bool * needs_write,FLAC__bool raw,const char ** violation)102 static FLAC__bool set_vc_field(FLAC__StreamMetadata *block, const Argument_VcField *field, FLAC__bool *needs_write, FLAC__bool raw, const char **violation)
103 {
104 FLAC__StreamMetadata_VorbisComment_Entry entry;
105 char *converted;
106
107 FLAC__ASSERT(0 != block);
108 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
109 FLAC__ASSERT(0 != field);
110 FLAC__ASSERT(0 != needs_write);
111
112 if(field->field_value_from_file) {
113 /* read the file into 'data' */
114 FILE *f = 0;
115 char *data = 0;
116 const off_t size = grabbag__file_get_filesize(field->field_value);
117 if(size < 0) {
118 *violation = "can't open file for tag value";
119 return false;
120 }
121 if(size >= 0x100000) { /* magic arbitrary limit, actual format limit is near 16MB */
122 *violation = "file for tag value is too large";
123 return false;
124 }
125 if(0 == (data = malloc(size+1)))
126 die("out of memory allocating tag value");
127 data[size] = '\0';
128 if(0 == (f = fopen(field->field_value, "rb")) || fread(data, 1, size, f) != (size_t)size) {
129 free(data);
130 if(f)
131 fclose(f);
132 *violation = "error while reading file for tag value";
133 return false;
134 }
135 fclose(f);
136 if(strlen(data) != (size_t)size) {
137 free(data);
138 *violation = "file for tag value has embedded NULs";
139 return false;
140 }
141
142 /* move 'data' into 'converted', converting to UTF-8 if necessary */
143 if(raw) {
144 converted = data;
145 }
146 else if(utf8_encode(data, &converted) >= 0) {
147 free(data);
148 }
149 else {
150 free(data);
151 *violation = "error converting file contents to UTF-8 for tag value";
152 return false;
153 }
154
155 /* create and entry and append it */
156 if(!FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair(&entry, field->field_name, converted)) {
157 free(converted);
158 *violation = "file for tag value is not valid UTF-8";
159 return false;
160 }
161 free(converted);
162 if(!FLAC__metadata_object_vorbiscomment_append_comment(block, entry, /*copy=*/false)) {
163 *violation = "memory allocation failure";
164 return false;
165 }
166
167 *needs_write = true;
168 return true;
169 }
170 else {
171 FLAC__bool needs_free = false;
172 if(raw) {
173 entry.entry = (FLAC__byte *)field->field;
174 }
175 else if(utf8_encode(field->field, &converted) >= 0) {
176 entry.entry = (FLAC__byte *)converted;
177 needs_free = true;
178 }
179 else {
180 *violation = "error converting comment to UTF-8";
181 return false;
182 }
183 entry.length = strlen((const char *)entry.entry);
184 if(!FLAC__format_vorbiscomment_entry_is_legal(entry.entry, entry.length)) {
185 if(needs_free)
186 free(converted);
187 /*
188 * our previous parsing has already established that the field
189 * name is OK, so it must be the field value
190 */
191 *violation = "tag value for is not valid UTF-8";
192 return false;
193 }
194
195 if(!FLAC__metadata_object_vorbiscomment_append_comment(block, entry, /*copy=*/true)) {
196 if(needs_free)
197 free(converted);
198 *violation = "memory allocation failure";
199 return false;
200 }
201
202 *needs_write = true;
203 if(needs_free)
204 free(converted);
205 return true;
206 }
207 }
208
209 /*
210 * The rest of the code is novel
211 */
212
free_field(Argument_VcField * obj)213 static void free_field(Argument_VcField *obj)
214 {
215 if(0 != obj->field)
216 free(obj->field);
217 if(0 != obj->field_name)
218 free(obj->field_name);
219 if(0 != obj->field_value)
220 free(obj->field_value);
221 }
222
flac__vorbiscomment_add(FLAC__StreamMetadata * block,const char * comment,FLAC__bool value_from_file,FLAC__bool raw,const char ** violation)223 FLAC__bool flac__vorbiscomment_add(FLAC__StreamMetadata *block, const char *comment, FLAC__bool value_from_file, FLAC__bool raw, const char **violation)
224 {
225 Argument_VcField parsed;
226 FLAC__bool dummy;
227
228 FLAC__ASSERT(0 != block);
229 FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
230 FLAC__ASSERT(0 != comment);
231
232 memset(&parsed, 0, sizeof(parsed));
233
234 parsed.field_value_from_file = value_from_file;
235 if(!parse_vorbis_comment_field(comment, &(parsed.field), &(parsed.field_name), &(parsed.field_value), &(parsed.field_value_length), violation)) {
236 free_field(&parsed);
237 return false;
238 }
239
240 if(!set_vc_field(block, &parsed, &dummy, raw, violation)) {
241 free_field(&parsed);
242 return false;
243 }
244 else {
245 free_field(&parsed);
246 return true;
247 }
248 }
249