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16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <crypto/hash_info.h>
19
20#include "ima.h"
21#include "ima_template_lib.h"
22
23static struct ima_template_desc defined_templates[] = {
24 {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
25 {.name = "ima-ng", .fmt = "d-ng|n-ng"},
26 {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
27 {.name = "", .fmt = ""},
28};
29
30static struct ima_template_field supported_fields[] = {
31 {.field_id = "d", .field_init = ima_eventdigest_init,
32 .field_show = ima_show_template_digest},
33 {.field_id = "n", .field_init = ima_eventname_init,
34 .field_show = ima_show_template_string},
35 {.field_id = "d-ng", .field_init = ima_eventdigest_ng_init,
36 .field_show = ima_show_template_digest_ng},
37 {.field_id = "n-ng", .field_init = ima_eventname_ng_init,
38 .field_show = ima_show_template_string},
39 {.field_id = "sig", .field_init = ima_eventsig_init,
40 .field_show = ima_show_template_sig},
41};
42
43static struct ima_template_desc *ima_template;
44static struct ima_template_desc *lookup_template_desc(const char *name);
45static int template_desc_init_fields(const char *template_fmt,
46 struct ima_template_field ***fields,
47 int *num_fields);
48
49static int __init ima_template_setup(char *str)
50{
51 struct ima_template_desc *template_desc;
52 int template_len = strlen(str);
53
54 if (ima_template)
55 return 1;
56
57
58
59
60
61 template_desc = lookup_template_desc(str);
62 if (!template_desc) {
63 pr_err("template %s not found, using %s\n",
64 str, CONFIG_IMA_DEFAULT_TEMPLATE);
65 return 1;
66 }
67
68
69
70
71
72 if (template_len == 3 && strcmp(str, IMA_TEMPLATE_IMA_NAME) == 0 &&
73 ima_hash_algo != HASH_ALGO_SHA1 && ima_hash_algo != HASH_ALGO_MD5) {
74 pr_err("template does not support hash alg\n");
75 return 1;
76 }
77
78 ima_template = template_desc;
79 return 1;
80}
81__setup("ima_template=", ima_template_setup);
82
83static int __init ima_template_fmt_setup(char *str)
84{
85 int num_templates = ARRAY_SIZE(defined_templates);
86
87 if (ima_template)
88 return 1;
89
90 if (template_desc_init_fields(str, NULL, NULL) < 0) {
91 pr_err("format string '%s' not valid, using template %s\n",
92 str, CONFIG_IMA_DEFAULT_TEMPLATE);
93 return 1;
94 }
95
96 defined_templates[num_templates - 1].fmt = str;
97 ima_template = defined_templates + num_templates - 1;
98 return 1;
99}
100__setup("ima_template_fmt=", ima_template_fmt_setup);
101
102static struct ima_template_desc *lookup_template_desc(const char *name)
103{
104 int i;
105
106 for (i = 0; i < ARRAY_SIZE(defined_templates); i++) {
107 if (strcmp(defined_templates[i].name, name) == 0)
108 return defined_templates + i;
109 }
110
111 return NULL;
112}
113
114static struct ima_template_field *lookup_template_field(const char *field_id)
115{
116 int i;
117
118 for (i = 0; i < ARRAY_SIZE(supported_fields); i++)
119 if (strncmp(supported_fields[i].field_id, field_id,
120 IMA_TEMPLATE_FIELD_ID_MAX_LEN) == 0)
121 return &supported_fields[i];
122 return NULL;
123}
124
125static int template_fmt_size(const char *template_fmt)
126{
127 char c;
128 int template_fmt_len = strlen(template_fmt);
129 int i = 0, j = 0;
130
131 while (i < template_fmt_len) {
132 c = template_fmt[i];
133 if (c == '|')
134 j++;
135 i++;
136 }
137
138 return j + 1;
139}
140
141static int template_desc_init_fields(const char *template_fmt,
142 struct ima_template_field ***fields,
143 int *num_fields)
144{
145 const char *template_fmt_ptr;
146 struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
147 int template_num_fields = template_fmt_size(template_fmt);
148 int i, len;
149
150 if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) {
151 pr_err("format string '%s' contains too many fields\n",
152 template_fmt);
153 return -EINVAL;
154 }
155
156 for (i = 0, template_fmt_ptr = template_fmt; i < template_num_fields;
157 i++, template_fmt_ptr += len + 1) {
158 char tmp_field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN + 1];
159
160 len = strchrnul(template_fmt_ptr, '|') - template_fmt_ptr;
161 if (len == 0 || len > IMA_TEMPLATE_FIELD_ID_MAX_LEN) {
162 pr_err("Invalid field with length %d\n", len);
163 return -EINVAL;
164 }
165
166 memcpy(tmp_field_id, template_fmt_ptr, len);
167 tmp_field_id[len] = '\0';
168 found_fields[i] = lookup_template_field(tmp_field_id);
169 if (!found_fields[i]) {
170 pr_err("field '%s' not found\n", tmp_field_id);
171 return -ENOENT;
172 }
173 }
174
175 if (fields && num_fields) {
176 *fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL);
177 if (*fields == NULL)
178 return -ENOMEM;
179
180 memcpy(*fields, found_fields, i * sizeof(*fields));
181 *num_fields = i;
182 }
183
184 return 0;
185}
186
187struct ima_template_desc *ima_template_desc_current(void)
188{
189 if (!ima_template)
190 ima_template =
191 lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
192 return ima_template;
193}
194
195int __init ima_init_template(void)
196{
197 struct ima_template_desc *template = ima_template_desc_current();
198 int result;
199
200 result = template_desc_init_fields(template->fmt,
201 &(template->fields),
202 &(template->num_fields));
203 if (result < 0)
204 pr_err("template %s init failed, result: %d\n",
205 (strlen(template->name) ?
206 template->name : template->fmt), result);
207
208 return result;
209}
210
