1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Parse command line, get partition information
4 *
5 * Written by Cai Zhiyong <caizhiyong@huawei.com>
6 *
7 */
8#include <linux/export.h>
9#include <linux/cmdline-parser.h>
10
11static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
12{
13	int ret = 0;
14	struct cmdline_subpart *new_subpart;
15
16	*subpart = NULL;
17
18	new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
19	if (!new_subpart)
20		return -ENOMEM;
21
22	if (*partdef == '-') {
23		new_subpart->size = (sector_t)(~0ULL);
24		partdef++;
25	} else {
26		new_subpart->size = (sector_t)memparse(partdef, &partdef);
27		if (new_subpart->size < (sector_t)PAGE_SIZE) {
28			pr_warn("cmdline partition size is invalid.");
29			ret = -EINVAL;
30			goto fail;
31		}
32	}
33
34	if (*partdef == '@') {
35		partdef++;
36		new_subpart->from = (sector_t)memparse(partdef, &partdef);
37	} else {
38		new_subpart->from = (sector_t)(~0ULL);
39	}
40
41	if (*partdef == '(') {
42		int length;
43		char *next = strchr(++partdef, ')');
44
45		if (!next) {
46			pr_warn("cmdline partition format is invalid.");
47			ret = -EINVAL;
48			goto fail;
49		}
50
51		length = min_t(int, next - partdef,
52			       sizeof(new_subpart->name) - 1);
53		strncpy(new_subpart->name, partdef, length);
54		new_subpart->name[length] = '\0';
55
56		partdef = ++next;
57	} else
58		new_subpart->name[0] = '\0';
59
60	new_subpart->flags = 0;
61
62	if (!strncmp(partdef, "ro", 2)) {
63		new_subpart->flags |= PF_RDONLY;
64		partdef += 2;
65	}
66
67	if (!strncmp(partdef, "lk", 2)) {
68		new_subpart->flags |= PF_POWERUP_LOCK;
69		partdef += 2;
70	}
71
72	*subpart = new_subpart;
73	return 0;
74fail:
75	kfree(new_subpart);
76	return ret;
77}
78
79static void free_subpart(struct cmdline_parts *parts)
80{
81	struct cmdline_subpart *subpart;
82
83	while (parts->subpart) {
84		subpart = parts->subpart;
85		parts->subpart = subpart->next_subpart;
86		kfree(subpart);
87	}
88}
89
90static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
91{
92	int ret = -EINVAL;
93	char *next;
94	int length;
95	struct cmdline_subpart **next_subpart;
96	struct cmdline_parts *newparts;
97	char buf[BDEVNAME_SIZE + 32 + 4];
98
99	*parts = NULL;
100
101	newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
102	if (!newparts)
103		return -ENOMEM;
104
105	next = strchr(bdevdef, ':');
106	if (!next) {
107		pr_warn("cmdline partition has no block device.");
108		goto fail;
109	}
110
111	length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
112	strncpy(newparts->name, bdevdef, length);
113	newparts->name[length] = '\0';
114	newparts->nr_subparts = 0;
115
116	next_subpart = &newparts->subpart;
117
118	while (next && *(++next)) {
119		bdevdef = next;
120		next = strchr(bdevdef, ',');
121
122		length = (!next) ? (sizeof(buf) - 1) :
123			min_t(int, next - bdevdef, sizeof(buf) - 1);
124
125		strncpy(buf, bdevdef, length);
126		buf[length] = '\0';
127
128		ret = parse_subpart(next_subpart, buf);
129		if (ret)
130			goto fail;
131
132		newparts->nr_subparts++;
133		next_subpart = &(*next_subpart)->next_subpart;
134	}
135
136	if (!newparts->subpart) {
137		pr_warn("cmdline partition has no valid partition.");
138		ret = -EINVAL;
139		goto fail;
140	}
141
142	*parts = newparts;
143
144	return 0;
145fail:
146	free_subpart(newparts);
147	kfree(newparts);
148	return ret;
149}
150
151void cmdline_parts_free(struct cmdline_parts **parts)
152{
153	struct cmdline_parts *next_parts;
154
155	while (*parts) {
156		next_parts = (*parts)->next_parts;
157		free_subpart(*parts);
158		kfree(*parts);
159		*parts = next_parts;
160	}
161}
162EXPORT_SYMBOL(cmdline_parts_free);
163
164int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
165{
166	int ret;
167	char *buf;
168	char *pbuf;
169	char *next;
170	struct cmdline_parts **next_parts;
171
172	*parts = NULL;
173
174	next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
175	if (!buf)
176		return -ENOMEM;
177
178	next_parts = parts;
179
180	while (next && *pbuf) {
181		next = strchr(pbuf, ';');
182		if (next)
183			*next = '\0';
184
185		ret = parse_parts(next_parts, pbuf);
186		if (ret)
187			goto fail;
188
189		if (next)
190			pbuf = ++next;
191
192		next_parts = &(*next_parts)->next_parts;
193	}
194
195	if (!*parts) {
196		pr_warn("cmdline partition has no valid partition.");
197		ret = -EINVAL;
198		goto fail;
199	}
200
201	ret = 0;
202done:
203	kfree(buf);
204	return ret;
205
206fail:
207	cmdline_parts_free(parts);
208	goto done;
209}
210EXPORT_SYMBOL(cmdline_parts_parse);
211
212struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
213					 const char *bdev)
214{
215	while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
216		parts = parts->next_parts;
217	return parts;
218}
219EXPORT_SYMBOL(cmdline_parts_find);
220
221/*
222 *  add_part()
223 *    0 success.
224 *    1 can not add so many partitions.
225 */
226int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
227		      int slot,
228		      int (*add_part)(int, struct cmdline_subpart *, void *),
229		      void *param)
230{
231	sector_t from = 0;
232	struct cmdline_subpart *subpart;
233
234	for (subpart = parts->subpart; subpart;
235	     subpart = subpart->next_subpart, slot++) {
236		if (subpart->from == (sector_t)(~0ULL))
237			subpart->from = from;
238		else
239			from = subpart->from;
240
241		if (from >= disk_size)
242			break;
243
244		if (subpart->size > (disk_size - from))
245			subpart->size = disk_size - from;
246
247		from += subpart->size;
248
249		if (add_part(slot, subpart, param))
250			break;
251	}
252
253	return slot;
254}
255EXPORT_SYMBOL(cmdline_parts_set);
256