summaryrefslogtreecommitdiff
path: root/src/audit.c
blob: 1b82c28f6f8b776001b925da70d6a140e9ed9d73 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/* audit.c - Alpine Package Keeper (APK)
 *
 * Copyright (C) 2005-2008 Natanael Copa <n@tanael.org>
 * Copyright (C) 2008-2011 Timo Teräs <timo.teras@iki.fi>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation. See http://www.gnu.org/ for details.
 */

#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <fnmatch.h>
#include <limits.h>
#include <sys/stat.h>
#include "apk_applet.h"
#include "apk_database.h"
#include "apk_print.h"

enum {
	MODE_BACKUP = 0,
	MODE_SYSTEM
};

struct audit_ctx {
	unsigned mode : 1;
	unsigned recursive : 1;
	unsigned check_permissions : 1;
	unsigned packages_only : 1;
};

static int audit_parse(void *ctx, struct apk_db_options *dbopts,
		       int optch, int optindex, const char *optarg)
{
	struct audit_ctx *actx = (struct audit_ctx *) ctx;

	switch (optch) {
	case 0x10000:
		actx->mode = MODE_BACKUP;
		break;
	case 0x10001:
		actx->mode = MODE_SYSTEM;
		break;
	case 0x10002:
		actx->check_permissions = 1;
		break;
	case 0x10003:
		actx->packages_only = 1;
		break;
	case 'r':
		actx->recursive = 1;
		break;
	default:
		return -1;
	}
	return 0;
}

struct audit_tree_ctx {
	struct audit_ctx *actx;
	struct apk_database *db;
	struct apk_db_dir *dir;
	size_t pathlen;
	char path[PATH_MAX];
};

static int audit_file(struct audit_ctx *actx,
		      struct apk_database *db,
		      struct apk_db_file *dbf,
		      int dirfd, const char *name)
{
	struct apk_file_info fi;

	if (dbf == NULL)
		return 'A';

	if (apk_file_get_info(dirfd, name, APK_FI_NOFOLLOW | dbf->csum.type, &fi) != 0)
		return -EPERM;

	if (dbf->csum.type != APK_CHECKSUM_NONE &&
	    apk_checksum_compare(&fi.csum, &dbf->csum) != 0)
		return 'U';

	if (S_ISLNK(fi.mode) && dbf->csum.type == APK_CHECKSUM_NONE)
		return 'U';

	if (actx->check_permissions &&
	    (dbf->mode != 0 || dbf->uid != 0 || dbf->gid != 0)) {
		if ((fi.mode & 07777) != (dbf->mode & 07777))
			return 'M';
		if (fi.uid != dbf->uid || fi.gid != dbf->gid)
			return 'M';
	}

	return 0;
}

static int audit_directory(struct audit_ctx *actx,
			   struct apk_database *db,
			   struct apk_db_dir *dbd,
			   struct apk_file_info *fi)
{
	if (dbd == NULL || dbd->refs == 1)
		return actx->recursive ? 'd' : 'D';

	if (actx->check_permissions &&
	    (dbd->mode != 0 || dbd->uid != 0 || dbd->gid != 0)) {
		if ((fi->mode & 07777) != (dbd->mode & 07777))
			return 'm';
		if (fi->uid != dbd->uid || fi->gid != dbd->gid)
			return 'm';
	}

	return 0;
}

static void report_audit(struct audit_ctx *actx,
			 char reason, apk_blob_t bfull, struct apk_package *pkg)
{
	if (!reason)
		return;

	if (actx->packages_only) {
		if (pkg == NULL || pkg->state_int != 0)
			return;
		pkg->state_int = 1;
		if (apk_verbosity < 1)
			printf("%s\n", pkg->name->name);
		else
			printf(PKG_VER_FMT "\n", PKG_VER_PRINTF(pkg));
	} else if (apk_verbosity < 1) {
		printf(BLOB_FMT "\n", BLOB_PRINTF(bfull));
	} else
		printf("%c " BLOB_FMT "\n", reason, BLOB_PRINTF(bfull));
}

static int audit_directory_tree_item(void *ctx, int dirfd, const char *name)
{
	struct audit_tree_ctx *atctx = (struct audit_tree_ctx *) ctx;
	apk_blob_t bdir = APK_BLOB_PTR_LEN(atctx->path, atctx->pathlen);
	apk_blob_t bent = APK_BLOB_STR(name);
	apk_blob_t bfull;
	struct audit_ctx *actx = atctx->actx;
	struct apk_database *db = atctx->db;
	struct apk_db_dir *dir = atctx->dir, *child = NULL;
	struct apk_file_info fi;
	int reason = 0;

	if (bdir.len + bent.len + 1 >= sizeof(atctx->path))
		return -ENOMEM;

	if (apk_file_get_info(dirfd, name, APK_FI_NOFOLLOW, &fi) < 0)
		return -EPERM;

	memcpy(&atctx->path[atctx->pathlen], bent.ptr, bent.len);
	atctx->pathlen += bent.len;
	bfull = APK_BLOB_PTR_LEN(atctx->path, atctx->pathlen);

	if (S_ISDIR(fi.mode)) {
		int recurse = TRUE;

		if (actx->mode == MODE_BACKUP) {
			child = apk_db_dir_get(db, bfull);
			if (!child->has_protected_children)
				recurse = FALSE;
			if (!child->protected)
				goto recurse_check;
		} else {
			child = apk_db_dir_query(db, bfull);
			if (child == NULL)
				goto done;
			child = apk_db_dir_ref(child);
		}

		reason = audit_directory(actx, db, child, &fi);
		if (reason < 0)
			goto done;

recurse_check:
		atctx->path[atctx->pathlen++] = '/';
		bfull.len++;
		report_audit(actx, reason, bfull, NULL);
		if (reason != 'D' && recurse) {
			atctx->dir = child;
			reason = apk_dir_foreach_file(
				openat(dirfd, name, O_RDONLY|O_CLOEXEC),
				audit_directory_tree_item, atctx);
			atctx->dir = dir;
		}
		bfull.len--;
		atctx->pathlen--;
	} else {
		struct apk_db_file *dbf;
		struct apk_protected_path *ppath;
		int protected = dir->protected, symlinks_only = dir->symlinks_only;

		/* inherit file's protection mask */
		foreach_array_item(ppath, dir->protected_paths) {
			char *slash = strchr(ppath->relative_pattern, '/');
			if (slash == NULL) {
				if (fnmatch(ppath->relative_pattern, name, FNM_PATHNAME) != 0)
					continue;
				protected = ppath->protected;
				symlinks_only = ppath->symlinks_only;
			}
		}

		if (actx->mode == MODE_BACKUP) {
			if (!protected)
				goto done;
			if (symlinks_only && !S_ISLNK(fi.mode))
				goto done;
		} else {
			if (protected)
				goto done;
		}

		dbf = apk_db_file_query(db, bdir, bent);
		reason = audit_file(actx, db, dbf, dirfd, name);
		if (reason < 0)
			goto done;
		if (reason == 'A' && actx->mode == MODE_SYSTEM)
			goto done;
		report_audit(actx, reason, bfull, dbf ? dbf->diri->pkg : NULL);
	}

done:
	if (child)
		apk_db_dir_unref(db, child, FALSE);

	atctx->pathlen -= bent.len;
	return reason < 0 ? reason : 0;
}

static int audit_main(void *ctx, struct apk_database *db, struct apk_string_array *args)
{
	struct audit_tree_ctx atctx;
	char **parg, *arg;
	int r = 0;

	atctx.db = db;
	atctx.actx = (struct audit_ctx *) ctx;
	atctx.pathlen = 0;
	atctx.path[0] = 0;

	if (args->num == 0) {
		atctx.dir = apk_db_dir_get(db, APK_BLOB_PTR_LEN(atctx.path, atctx.pathlen));
		r = apk_dir_foreach_file(dup(db->root_fd), audit_directory_tree_item, &atctx);
		apk_db_dir_unref(db, atctx.dir, FALSE);
		return r;
	}

	foreach_array_item(parg, args) {
		arg = *parg;
		if (arg[0] != '/') {
			apk_warning("%s: relative path skipped.\n", arg);
			continue;
		}
		arg++;
		atctx.pathlen = strlen(arg);
		memcpy(atctx.path, arg, atctx.pathlen);
		if (atctx.path[atctx.pathlen-1] != '/')
			atctx.path[atctx.pathlen++] = '/';

		atctx.dir = apk_db_dir_get(db, APK_BLOB_PTR_LEN(atctx.path, atctx.pathlen));
		r |= apk_dir_foreach_file(openat(db->root_fd, arg, O_RDONLY|O_CLOEXEC),
					  audit_directory_tree_item, &atctx);
		apk_db_dir_unref(db, atctx.dir, FALSE);
	}
	return r;
}

static struct apk_option audit_options[] = {
	{ 0x10000, "backup", "List all modified configuration files (in "
			     "protected_paths.d) that need to be backed up" },
	{ 0x10001, "system", "Verify checksums of all installed non-configuration files " },
	{ 0x10002, "check-permissions", "Check file and directory uid/gid/mode too" },
	{ 'r', "recursive",  "List individually all entries in new directories" },
	{ 0x10003, "packages", "List only the changed packages (or names only with -q)" },
};

static struct apk_applet apk_audit = {
	.name = "audit",
	.help = "Audit the directories for changes",
	.arguments = "[directory to audit]...",
	.open_flags = APK_OPENF_READ|APK_OPENF_NO_SCRIPTS|APK_OPENF_NO_REPOS,
	.context_size = sizeof(struct audit_ctx),
	.num_options = ARRAY_SIZE(audit_options),
	.options = audit_options,
	.parse = audit_parse,
	.main = audit_main,
};

APK_DEFINE_APPLET(apk_audit);