1/*
  2 * Parse command line, get partition information
  3 *
  4 * Written by Cai Zhiyong <caizhiyong@huawei.com>
  5 *
  6 */
  7#include <linux/export.h>
  8#include <linux/cmdline-parser.h>
  9
 10static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
 11{
 12	int ret = 0;
 13	struct cmdline_subpart *new_subpart;
 14
 15	*subpart = NULL;
 16
 17	new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
 18	if (!new_subpart)
 19		return -ENOMEM;
 20
 21	if (*partdef == '-') {
 22		new_subpart->size = (sector_t)(~0ULL);
 23		partdef++;
 24	} else {
 25		new_subpart->size = (sector_t)memparse(partdef, &partdef);
 26		if (new_subpart->size < (sector_t)PAGE_SIZE) {
 27			pr_warn("cmdline partition size is invalid.");
 28			ret = -EINVAL;
 29			goto fail;
 30		}
 31	}
 32
 33	if (*partdef == '@') {
 34		partdef++;
 35		new_subpart->from = (sector_t)memparse(partdef, &partdef);
 36	} else {
 37		new_subpart->from = (sector_t)(~0ULL);
 38	}
 39
 40	if (*partdef == '(') {
 41		int length;
 42		char *next = strchr(++partdef, ')');
 43
 44		if (!next) {
 45			pr_warn("cmdline partition format is invalid.");
 46			ret = -EINVAL;
 47			goto fail;
 48		}
 49
 50		length = min_t(int, next - partdef,
 51			       sizeof(new_subpart->name) - 1);
 52		strncpy(new_subpart->name, partdef, length);
 53		new_subpart->name[length] = '\0';
 54
 55		partdef = ++next;
 56	} else
 57		new_subpart->name[0] = '\0';
 58
 59	new_subpart->flags = 0;
 60
 61	if (!strncmp(partdef, "ro", 2)) {
 62		new_subpart->flags |= PF_RDONLY;
 63		partdef += 2;
 64	}
 65
 66	if (!strncmp(partdef, "lk", 2)) {
 67		new_subpart->flags |= PF_POWERUP_LOCK;
 68		partdef += 2;
 69	}
 70
 71	*subpart = new_subpart;
 72	return 0;
 73fail:
 74	kfree(new_subpart);
 75	return ret;
 76}
 77
 78static void free_subpart(struct cmdline_parts *parts)
 79{
 80	struct cmdline_subpart *subpart;
 81
 82	while (parts->subpart) {
 83		subpart = parts->subpart;
 84		parts->subpart = subpart->next_subpart;
 85		kfree(subpart);
 86	}
 87}
 88
 89static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
 90{
 91	int ret = -EINVAL;
 92	char *next;
 93	int length;
 94	struct cmdline_subpart **next_subpart;
 95	struct cmdline_parts *newparts;
 96	char buf[BDEVNAME_SIZE + 32 + 4];
 97
 98	*parts = NULL;
 99
100	newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
101	if (!newparts)
102		return -ENOMEM;
103
104	next = strchr(bdevdef, ':');
105	if (!next) {
106		pr_warn("cmdline partition has no block device.");
107		goto fail;
108	}
109
110	length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
111	strncpy(newparts->name, bdevdef, length);
112	newparts->name[length] = '\0';
113	newparts->nr_subparts = 0;
114
115	next_subpart = &newparts->subpart;
116
117	while (next && *(++next)) {
118		bdevdef = next;
119		next = strchr(bdevdef, ',');
120
121		length = (!next) ? (sizeof(buf) - 1) :
122			min_t(int, next - bdevdef, sizeof(buf) - 1);
123
124		strncpy(buf, bdevdef, length);
125		buf[length] = '\0';
126
127		ret = parse_subpart(next_subpart, buf);
128		if (ret)
129			goto fail;
130
131		newparts->nr_subparts++;
132		next_subpart = &(*next_subpart)->next_subpart;
133	}
134
135	if (!newparts->subpart) {
136		pr_warn("cmdline partition has no valid partition.");
137		ret = -EINVAL;
138		goto fail;
139	}
140
141	*parts = newparts;
142
143	return 0;
144fail:
145	free_subpart(newparts);
146	kfree(newparts);
147	return ret;
148}
149
150void cmdline_parts_free(struct cmdline_parts **parts)
151{
152	struct cmdline_parts *next_parts;
153
154	while (*parts) {
155		next_parts = (*parts)->next_parts;
156		free_subpart(*parts);
157		kfree(*parts);
158		*parts = next_parts;
159	}
160}
161EXPORT_SYMBOL(cmdline_parts_free);
162
163int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
164{
165	int ret;
166	char *buf;
167	char *pbuf;
168	char *next;
169	struct cmdline_parts **next_parts;
170
171	*parts = NULL;
172
173	next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
174	if (!buf)
175		return -ENOMEM;
176
177	next_parts = parts;
178
179	while (next && *pbuf) {
180		next = strchr(pbuf, ';');
181		if (next)
182			*next = '\0';
183
184		ret = parse_parts(next_parts, pbuf);
185		if (ret)
186			goto fail;
187
188		if (next)
189			pbuf = ++next;
190
191		next_parts = &(*next_parts)->next_parts;
192	}
193
194	if (!*parts) {
195		pr_warn("cmdline partition has no valid partition.");
196		ret = -EINVAL;
197		goto fail;
198	}
199
200	ret = 0;
201done:
202	kfree(buf);
203	return ret;
204
205fail:
206	cmdline_parts_free(parts);
207	goto done;
208}
209EXPORT_SYMBOL(cmdline_parts_parse);
210
211struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
212					 const char *bdev)
213{
214	while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
215		parts = parts->next_parts;
216	return parts;
217}
218EXPORT_SYMBOL(cmdline_parts_find);
219
220/*
221 *  add_part()
222 *    0 success.
223 *    1 can not add so many partitions.
224 */
225int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
226		      int slot,
227		      int (*add_part)(int, struct cmdline_subpart *, void *),
228		      void *param)
229{
230	sector_t from = 0;
231	struct cmdline_subpart *subpart;
232
233	for (subpart = parts->subpart; subpart;
234	     subpart = subpart->next_subpart, slot++) {
235		if (subpart->from == (sector_t)(~0ULL))
236			subpart->from = from;
237		else
238			from = subpart->from;
239
240		if (from >= disk_size)
241			break;
242
243		if (subpart->size > (disk_size - from))
244			subpart->size = disk_size - from;
245
246		from += subpart->size;
247
248		if (add_part(slot, subpart, param))
249			break;
250	}
251
252	return slot;
253}
254EXPORT_SYMBOL(cmdline_parts_set);