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
parse_subpart(struct cmdline_subpart ** subpart,char * partdef)11 static 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;
74 fail:
75 kfree(new_subpart);
76 return ret;
77 }
78
free_subpart(struct cmdline_parts * parts)79 static 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
parse_parts(struct cmdline_parts ** parts,const char * bdevdef)90 static 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;
145 fail:
146 free_subpart(newparts);
147 kfree(newparts);
148 return ret;
149 }
150
cmdline_parts_free(struct cmdline_parts ** parts)151 void 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 }
162 EXPORT_SYMBOL(cmdline_parts_free);
163
cmdline_parts_parse(struct cmdline_parts ** parts,const char * cmdline)164 int 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;
202 done:
203 kfree(buf);
204 return ret;
205
206 fail:
207 cmdline_parts_free(parts);
208 goto done;
209 }
210 EXPORT_SYMBOL(cmdline_parts_parse);
211
cmdline_parts_find(struct cmdline_parts * parts,const char * bdev)212 struct 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 }
219 EXPORT_SYMBOL(cmdline_parts_find);
220
221 /*
222 * add_part()
223 * 0 success.
224 * 1 can not add so many partitions.
225 */
cmdline_parts_set(struct cmdline_parts * parts,sector_t disk_size,int slot,int (* add_part)(int,struct cmdline_subpart *,void *),void * param)226 int 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 }
255 EXPORT_SYMBOL(cmdline_parts_set);
256