verified_exec.h revision 1.27 1 /* $NetBSD: verified_exec.h,v 1.27 2005/12/12 16:26:34 elad Exp $ */
2
3 /*-
4 * Copyright 2005 Elad Efrat <elad (at) bsd.org.il>
5 * Copyright 2005 Brett Lymn <blymn (at) netbsd.org>
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Brett Lymn and Elad Efrat
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Neither the name of The NetBSD Foundation nor the names of its
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef _SYS_VERIFIED_EXEC_H_
33 #define _SYS_VERIFIED_EXEC_H_
34
35 #include <sys/cdefs.h>
36 #include <sys/param.h>
37 #include <sys/hash.h>
38 #include <uvm/uvm_extern.h>
39 #include <uvm/uvm_pglist.h>
40 #include <uvm/uvm_page.h>
41
42 /* Max length of the fingerprint type string, including terminating \0 char */
43 #define VERIEXEC_TYPE_MAXLEN 9
44
45 struct veriexec_params {
46 unsigned char type;
47 unsigned char fp_type[VERIEXEC_TYPE_MAXLEN];
48 char file[MAXPATHLEN];
49 unsigned int size; /* number of bytes in the fingerprint */
50 unsigned char *fingerprint;
51 };
52
53 struct veriexec_sizing_params {
54 dev_t dev;
55 size_t hash_size;
56 };
57
58 struct veriexec_delete_params {
59 dev_t dev;
60 ino_t ino;
61 };
62
63 /* Flags for a Veriexec entry. These can be OR'd together. */
64 #define VERIEXEC_DIRECT 0x01 /* Direct execution (exec) */
65 #define VERIEXEC_INDIRECT 0x02 /* Indirect execution (#!) */
66 #define VERIEXEC_FILE 0x04 /* Plain file (open) */
67 #define VERIEXEC_UNTRUSTED 0x10 /* Untrusted storage */
68
69 /* Operations for /dev/veriexec. */
70 #define VERIEXEC_LOAD _IOW('S', 0x1, struct veriexec_params)
71 #define VERIEXEC_TABLESIZE _IOW('S', 0x2, struct veriexec_sizing_params)
72 #define VERIEXEC_DELETE _IOW('S', 0x3, struct veriexec_delete_params)
73
74 /* Verified exec sysctl objects. */
75 #define VERIEXEC_VERBOSE 1 /* Verbosity level. */
76 #define VERIEXEC_STRICT 2 /* Strict mode level. */
77 #define VERIEXEC_ALGORITHMS 3 /* Supported hashing algorithms. */
78 #define VERIEXEC_COUNT 4 /* # of fingerprinted files on device. */
79
80 #ifdef _KERNEL
81 void veriexecattach(struct device *, struct device *, void *);
82 int veriexecopen(dev_t, int, int, struct lwp *);
83 int veriexecclose(dev_t, int, int, struct lwp *);
84 int veriexecioctl(dev_t, u_long, caddr_t, int, struct lwp *);
85
86 /* defined in kern_verifiedexec.c */
87 extern char *veriexec_fp_names;
88 extern int veriexec_verbose;
89 extern int veriexec_strict;
90 /* this one requires sysctl.h to be included before verified_exec.h */
91 #ifdef VERIEXEC_NEED_NODE
92 extern const struct sysctlnode *veriexec_count_node;
93 #endif /* VERIEXEC_NEED_NODE */
94
95 /*
96 * Operations vector for verified exec, this defines the characteristics
97 * for the fingerprint type.
98 * Function types: init, update, final.
99 */
100 typedef void (*VERIEXEC_INIT_FN)(void *);
101 typedef void (*VERIEXEC_UPDATE_FN)(void *, u_char *, u_int);
102 typedef void (*VERIEXEC_FINAL_FN)(u_char *, void *);
103
104 struct veriexec_fp_ops {
105 char type[VERIEXEC_TYPE_MAXLEN];
106 size_t hash_len;
107 size_t context_size;
108 VERIEXEC_INIT_FN init;
109 VERIEXEC_UPDATE_FN update;
110 VERIEXEC_FINAL_FN final;
111 LIST_ENTRY(veriexec_fp_ops) entries;
112 };
113
114 /* An entry in the per-device hash table. */
115 struct veriexec_hash_entry {
116 ino_t inode; /* Inode number. */
117 unsigned char type; /* Entry type. */
118 unsigned char status; /* Evaluation status. */
119 unsigned char page_fp_status; /* Per-page FP status. */
120 unsigned char *fp; /* Fingerprint. */
121 void *page_fp; /* Per-page fingerprints */
122 size_t npages; /* Number of pages. */
123 size_t last_page_size; /* To support < PAGE_SIZE */
124 struct veriexec_fp_ops *ops; /* Fingerprint ops vector*/
125 LIST_ENTRY(veriexec_hash_entry) entries; /* List pointer. */
126 };
127
128 /* Valid status field values. */
129 #define FINGERPRINT_NOTEVAL 0 /* fingerprint has not been evaluated */
130 #define FINGERPRINT_VALID 1 /* fingerprint evaluated and matches list */
131 #define FINGERPRINT_NOMATCH 2 /* fingerprint evaluated but does not match */
132
133 /* Per-page fingerprint status. */
134 #define PAGE_FP_NONE 0 /* no per-page fingerprints. */
135 #define PAGE_FP_READY 1 /* per-page fingerprints ready for use. */
136 #define PAGE_FP_FAIL 2 /* mismatch in per-page fingerprints. */
137
138 LIST_HEAD(veriexec_hashhead, veriexec_hash_entry);
139
140 /* Veriexec hash table information. */
141 struct veriexec_hashtbl {
142 struct veriexec_hashhead *hash_tbl;
143 size_t hash_size; /* Number of slots in the table. */
144 dev_t hash_dev; /* Device ID the hash table refers to. */
145 uint64_t hash_count; /* # of fingerprinted files in table. */
146 LIST_ENTRY(veriexec_hashtbl) hash_list;
147 };
148
149 /* Global list of hash tables, one per device. */
150 LIST_HEAD(, veriexec_hashtbl) veriexec_tables;
151
152 /* Mask to ensure bounded access to elements in the hash table. */
153 #define VERIEXEC_HASH_MASK(tbl) ((tbl)->hash_size - 1)
154
155 /* Readable values for veriexec_report(). */
156 #define REPORT_NOVERBOSE 0 /* Always print */
157 #define REPORT_VERBOSE 1 /* Print when verbose >= 1 */
158 #define REPORT_VERBOSE_HIGH 2 /* Print when verbose >= 2 (debug) */
159 #define REPORT_NOPANIC 0 /* Normal report */
160 #define REPORT_PANIC 1 /* Use panic() */
161 #define REPORT_NOALARM 0 /* Normal report */
162 #define REPORT_ALARM 1 /* Alarm - also print pid/uid/.. */
163
164 /*
165 * Hashing function: Takes an inode number modulus the mask to give back
166 * an index into the hash table.
167 */
168 #define VERIEXEC_HASH(tbl, inode) \
169 (hash32_buf(&(inode), sizeof((inode)), HASH32_BUF_INIT) \
170 & VERIEXEC_HASH_MASK(tbl))
171
172 /* Initialize a fingerprint ops struct. */
173 #define VERIEXEC_OPINIT(ops, fp_type, hashlen, ctx_size, init_fn, \
174 update_fn, final_fn) \
175 do { \
176 (void) strlcpy((ops)->type, fp_type, sizeof((ops)->type)); \
177 (ops)->hash_len = (hashlen); \
178 (ops)->context_size = (ctx_size); \
179 (ops)->init = (VERIEXEC_INIT_FN) (init_fn); \
180 (ops)->update = (VERIEXEC_UPDATE_FN) (update_fn); \
181 (ops)->final = (VERIEXEC_FINAL_FN) (final_fn); \
182 } while (0);
183
184 int veriexec_add_fp_ops(struct veriexec_fp_ops *);
185 void veriexec_init_fp_ops(void);
186 struct veriexec_fp_ops *veriexec_find_ops(u_char *name);
187 int veriexec_fp_calc(struct lwp *, struct vnode *,
188 struct veriexec_hash_entry *, uint64_t, u_char *);
189 int veriexec_fp_cmp(struct veriexec_fp_ops *, u_char *, u_char *);
190 struct veriexec_hashtbl *veriexec_tblfind(dev_t);
191 struct veriexec_hash_entry *veriexec_lookup(dev_t, ino_t);
192 int veriexec_hashadd(struct veriexec_hashtbl *, struct veriexec_hash_entry *);
193 int veriexec_verify(struct lwp *, struct vnode *, struct vattr *,
194 const u_char *, int, struct veriexec_hash_entry **);
195 int veriexec_page_verify(struct veriexec_hash_entry *, struct vattr *,
196 struct vm_page *, size_t, struct lwp *);
197 int veriexec_removechk(struct lwp *, struct vnode *, const char *);
198 int veriexec_renamechk(struct vnode *, const char *, const char *,
199 struct lwp *);
200 void veriexec_init_fp_ops(void);
201 void veriexec_report(const u_char *, const u_char *, struct vattr *,
202 struct lwp *, int, int, int);
203 int veriexec_newtable(struct veriexec_sizing_params *);
204 int veriexec_load(struct veriexec_params *, struct lwp *);
205 int veriexec_delete(struct veriexec_delete_params *);
206
207 #endif /* _KERNEL */
208
209 #endif /* !_SYS_VERIFIED_EXEC_H_ */
210