1 /*
2 * String parsing visitor
3 *
4 * Copyright Red Hat, Inc. 2012-2016
5 *
6 * Author: Paolo Bonzini <pbonzini@redhat.com>
7 * David Hildenbrand <david@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
10 * See the COPYING.LIB file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qapi/error.h"
15 #include "qapi/string-input-visitor.h"
16 #include "qapi/visitor-impl.h"
17 #include "qapi/qmp/qerror.h"
18 #include "qapi/qmp/qnull.h"
19 #include "qemu/option.h"
20 #include "qemu/cutils.h"
21
22 typedef enum ListMode {
23 /* no list parsing active / no list expected */
24 LM_NONE,
25 /* we have an unparsed string remaining */
26 LM_UNPARSED,
27 /* we have an unfinished int64 range */
28 LM_INT64_RANGE,
29 /* we have an unfinished uint64 range */
30 LM_UINT64_RANGE,
31 /* we have parsed the string completely and no range is remaining */
32 LM_END,
33 } ListMode;
34
35 /* protect against DOS attacks, limit the amount of elements per range */
36 #define RANGE_MAX_ELEMENTS 65536
37
38 typedef union RangeElement {
39 int64_t i64;
40 uint64_t u64;
41 } RangeElement;
42
43 struct StringInputVisitor
44 {
45 Visitor visitor;
46
47 /* List parsing state */
48 ListMode lm;
49 RangeElement rangeNext;
50 RangeElement rangeEnd;
51 const char *unparsed_string;
52 void *list;
53
54 /* The original string to parse */
55 const char *string;
56 };
57
to_siv(Visitor * v)58 static StringInputVisitor *to_siv(Visitor *v)
59 {
60 return container_of(v, StringInputVisitor, visitor);
61 }
62
start_list(Visitor * v,const char * name,GenericList ** list,size_t size,Error ** errp)63 static bool start_list(Visitor *v, const char *name, GenericList **list,
64 size_t size, Error **errp)
65 {
66 StringInputVisitor *siv = to_siv(v);
67
68 assert(siv->lm == LM_NONE);
69 siv->list = list;
70 siv->unparsed_string = siv->string;
71
72 if (!siv->string[0]) {
73 if (list) {
74 *list = NULL;
75 }
76 siv->lm = LM_END;
77 } else {
78 if (list) {
79 *list = g_malloc0(size);
80 }
81 siv->lm = LM_UNPARSED;
82 }
83 return true;
84 }
85
next_list(Visitor * v,GenericList * tail,size_t size)86 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
87 {
88 StringInputVisitor *siv = to_siv(v);
89
90 switch (siv->lm) {
91 case LM_END:
92 return NULL;
93 case LM_INT64_RANGE:
94 case LM_UINT64_RANGE:
95 case LM_UNPARSED:
96 /* we have an unparsed string or something left in a range */
97 break;
98 default:
99 abort();
100 }
101
102 tail->next = g_malloc0(size);
103 return tail->next;
104 }
105
check_list(Visitor * v,Error ** errp)106 static bool check_list(Visitor *v, Error **errp)
107 {
108 const StringInputVisitor *siv = to_siv(v);
109
110 switch (siv->lm) {
111 case LM_INT64_RANGE:
112 case LM_UINT64_RANGE:
113 case LM_UNPARSED:
114 error_setg(errp, "Fewer list elements expected");
115 return false;
116 case LM_END:
117 return true;
118 default:
119 abort();
120 }
121 }
122
end_list(Visitor * v,void ** obj)123 static void end_list(Visitor *v, void **obj)
124 {
125 StringInputVisitor *siv = to_siv(v);
126
127 assert(siv->lm != LM_NONE);
128 assert(siv->list == obj);
129 siv->list = NULL;
130 siv->unparsed_string = NULL;
131 siv->lm = LM_NONE;
132 }
133
try_parse_int64_list_entry(StringInputVisitor * siv,int64_t * obj)134 static int try_parse_int64_list_entry(StringInputVisitor *siv, int64_t *obj)
135 {
136 const char *endptr;
137 int64_t start, end;
138
139 /* parse a simple int64 or range */
140 if (qemu_strtoi64(siv->unparsed_string, &endptr, 0, &start)) {
141 return -EINVAL;
142 }
143 end = start;
144
145 switch (endptr[0]) {
146 case '\0':
147 siv->unparsed_string = endptr;
148 break;
149 case ',':
150 siv->unparsed_string = endptr + 1;
151 break;
152 case '-':
153 /* parse the end of the range */
154 if (qemu_strtoi64(endptr + 1, &endptr, 0, &end)) {
155 return -EINVAL;
156 }
157 if (start > end || end - start >= RANGE_MAX_ELEMENTS) {
158 return -EINVAL;
159 }
160 switch (endptr[0]) {
161 case '\0':
162 siv->unparsed_string = endptr;
163 break;
164 case ',':
165 siv->unparsed_string = endptr + 1;
166 break;
167 default:
168 return -EINVAL;
169 }
170 break;
171 default:
172 return -EINVAL;
173 }
174
175 /* we have a proper range (with maybe only one element) */
176 siv->lm = LM_INT64_RANGE;
177 siv->rangeNext.i64 = start;
178 siv->rangeEnd.i64 = end;
179 return 0;
180 }
181
parse_type_int64(Visitor * v,const char * name,int64_t * obj,Error ** errp)182 static bool parse_type_int64(Visitor *v, const char *name, int64_t *obj,
183 Error **errp)
184 {
185 StringInputVisitor *siv = to_siv(v);
186 int64_t val;
187
188 switch (siv->lm) {
189 case LM_NONE:
190 /* just parse a simple int64, bail out if not completely consumed */
191 if (qemu_strtoi64(siv->string, NULL, 0, &val)) {
192 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
193 name ? name : "null", "int64");
194 return false;
195 }
196 *obj = val;
197 return true;
198 case LM_UNPARSED:
199 if (try_parse_int64_list_entry(siv, obj)) {
200 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
201 "list of int64 values or ranges");
202 return false;
203 }
204 assert(siv->lm == LM_INT64_RANGE);
205 /* fall through */
206 case LM_INT64_RANGE:
207 /* return the next element in the range */
208 assert(siv->rangeNext.i64 <= siv->rangeEnd.i64);
209 *obj = siv->rangeNext.i64++;
210
211 if (siv->rangeNext.i64 > siv->rangeEnd.i64 || *obj == INT64_MAX) {
212 /* end of range, check if there is more to parse */
213 siv->lm = siv->unparsed_string[0] ? LM_UNPARSED : LM_END;
214 }
215 return true;
216 case LM_END:
217 error_setg(errp, "Fewer list elements expected");
218 return false;
219 default:
220 abort();
221 }
222 }
223
try_parse_uint64_list_entry(StringInputVisitor * siv,uint64_t * obj)224 static int try_parse_uint64_list_entry(StringInputVisitor *siv, uint64_t *obj)
225 {
226 const char *endptr;
227 uint64_t start, end;
228
229 /* parse a simple uint64 or range */
230 if (qemu_strtou64(siv->unparsed_string, &endptr, 0, &start)) {
231 return -EINVAL;
232 }
233 end = start;
234
235 switch (endptr[0]) {
236 case '\0':
237 siv->unparsed_string = endptr;
238 break;
239 case ',':
240 siv->unparsed_string = endptr + 1;
241 break;
242 case '-':
243 /* parse the end of the range */
244 if (qemu_strtou64(endptr + 1, &endptr, 0, &end)) {
245 return -EINVAL;
246 }
247 if (start > end || end - start >= RANGE_MAX_ELEMENTS) {
248 return -EINVAL;
249 }
250 switch (endptr[0]) {
251 case '\0':
252 siv->unparsed_string = endptr;
253 break;
254 case ',':
255 siv->unparsed_string = endptr + 1;
256 break;
257 default:
258 return -EINVAL;
259 }
260 break;
261 default:
262 return -EINVAL;
263 }
264
265 /* we have a proper range (with maybe only one element) */
266 siv->lm = LM_UINT64_RANGE;
267 siv->rangeNext.u64 = start;
268 siv->rangeEnd.u64 = end;
269 return 0;
270 }
271
parse_type_uint64(Visitor * v,const char * name,uint64_t * obj,Error ** errp)272 static bool parse_type_uint64(Visitor *v, const char *name, uint64_t *obj,
273 Error **errp)
274 {
275 StringInputVisitor *siv = to_siv(v);
276 uint64_t val;
277
278 switch (siv->lm) {
279 case LM_NONE:
280 /* just parse a simple uint64, bail out if not completely consumed */
281 if (qemu_strtou64(siv->string, NULL, 0, &val)) {
282 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
283 "uint64");
284 return false;
285 }
286 *obj = val;
287 return true;
288 case LM_UNPARSED:
289 if (try_parse_uint64_list_entry(siv, obj)) {
290 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
291 "list of uint64 values or ranges");
292 return false;
293 }
294 assert(siv->lm == LM_UINT64_RANGE);
295 /* fall through */
296 case LM_UINT64_RANGE:
297 /* return the next element in the range */
298 assert(siv->rangeNext.u64 <= siv->rangeEnd.u64);
299 *obj = siv->rangeNext.u64++;
300
301 if (siv->rangeNext.u64 > siv->rangeEnd.u64 || *obj == UINT64_MAX) {
302 /* end of range, check if there is more to parse */
303 siv->lm = siv->unparsed_string[0] ? LM_UNPARSED : LM_END;
304 }
305 return true;
306 case LM_END:
307 error_setg(errp, "Fewer list elements expected");
308 return false;
309 default:
310 abort();
311 }
312 }
313
parse_type_size(Visitor * v,const char * name,uint64_t * obj,Error ** errp)314 static bool parse_type_size(Visitor *v, const char *name, uint64_t *obj,
315 Error **errp)
316 {
317 StringInputVisitor *siv = to_siv(v);
318 uint64_t val;
319
320 assert(siv->lm == LM_NONE);
321 if (!parse_option_size(name, siv->string, &val, errp)) {
322 return false;
323 }
324
325 *obj = val;
326 return true;
327 }
328
parse_type_bool(Visitor * v,const char * name,bool * obj,Error ** errp)329 static bool parse_type_bool(Visitor *v, const char *name, bool *obj,
330 Error **errp)
331 {
332 StringInputVisitor *siv = to_siv(v);
333
334 assert(siv->lm == LM_NONE);
335 return qapi_bool_parse(name ? name : "null", siv->string, obj, errp);
336 }
337
parse_type_str(Visitor * v,const char * name,char ** obj,Error ** errp)338 static bool parse_type_str(Visitor *v, const char *name, char **obj,
339 Error **errp)
340 {
341 StringInputVisitor *siv = to_siv(v);
342
343 assert(siv->lm == LM_NONE);
344 *obj = g_strdup(siv->string);
345 return true;
346 }
347
parse_type_number(Visitor * v,const char * name,double * obj,Error ** errp)348 static bool parse_type_number(Visitor *v, const char *name, double *obj,
349 Error **errp)
350 {
351 StringInputVisitor *siv = to_siv(v);
352 double val;
353
354 assert(siv->lm == LM_NONE);
355 if (qemu_strtod_finite(siv->string, NULL, &val)) {
356 error_setg(errp, "Invalid parameter type for '%s', expected: number",
357 name ? name : "null");
358 return false;
359 }
360
361 *obj = val;
362 return true;
363 }
364
parse_type_null(Visitor * v,const char * name,QNull ** obj,Error ** errp)365 static bool parse_type_null(Visitor *v, const char *name, QNull **obj,
366 Error **errp)
367 {
368 StringInputVisitor *siv = to_siv(v);
369
370 assert(siv->lm == LM_NONE);
371 *obj = NULL;
372
373 if (siv->string[0]) {
374 error_setg(errp, "Invalid parameter type for '%s', expected: null",
375 name ? name : "null");
376 return false;
377 }
378
379 *obj = qnull();
380 return true;
381 }
382
string_input_free(Visitor * v)383 static void string_input_free(Visitor *v)
384 {
385 StringInputVisitor *siv = to_siv(v);
386
387 g_free(siv);
388 }
389
string_input_visitor_new(const char * str)390 Visitor *string_input_visitor_new(const char *str)
391 {
392 StringInputVisitor *v;
393
394 assert(str);
395 v = g_malloc0(sizeof(*v));
396
397 v->visitor.type = VISITOR_INPUT;
398 v->visitor.type_int64 = parse_type_int64;
399 v->visitor.type_uint64 = parse_type_uint64;
400 v->visitor.type_size = parse_type_size;
401 v->visitor.type_bool = parse_type_bool;
402 v->visitor.type_str = parse_type_str;
403 v->visitor.type_number = parse_type_number;
404 v->visitor.type_null = parse_type_null;
405 v->visitor.start_list = start_list;
406 v->visitor.next_list = next_list;
407 v->visitor.check_list = check_list;
408 v->visitor.end_list = end_list;
409 v->visitor.free = string_input_free;
410
411 v->string = str;
412 v->lm = LM_NONE;
413 return &v->visitor;
414 }
415