xref: /linux/security/apparmor/net.c (revision bd7bd201ca46c211c3ab251ca9854787d1331a2f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AppArmor security module
4  *
5  * This file contains AppArmor network mediation
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2017 Canonical Ltd.
9  */
10 
11 #include "include/apparmor.h"
12 #include "include/audit.h"
13 #include "include/cred.h"
14 #include "include/label.h"
15 #include "include/net.h"
16 #include "include/policy.h"
17 #include "include/secid.h"
18 
19 #include "net_names.h"
20 
21 
22 struct aa_sfs_entry aa_sfs_entry_network[] = {
23 	AA_SFS_FILE_STRING("af_mask",	AA_SFS_AF_MASK),
24 	{ }
25 };
26 
27 static const char * const net_mask_names[] = {
28 	"unknown",
29 	"send",
30 	"receive",
31 	"unknown",
32 
33 	"create",
34 	"shutdown",
35 	"connect",
36 	"unknown",
37 
38 	"setattr",
39 	"getattr",
40 	"setcred",
41 	"getcred",
42 
43 	"chmod",
44 	"chown",
45 	"chgrp",
46 	"lock",
47 
48 	"mmap",
49 	"mprot",
50 	"unknown",
51 	"unknown",
52 
53 	"accept",
54 	"bind",
55 	"listen",
56 	"unknown",
57 
58 	"setopt",
59 	"getopt",
60 	"unknown",
61 	"unknown",
62 
63 	"unknown",
64 	"unknown",
65 	"unknown",
66 	"unknown",
67 };
68 
69 
70 /* audit callback for net specific fields */
71 void audit_net_cb(struct audit_buffer *ab, void *va)
72 {
73 	struct common_audit_data *sa = va;
74 	struct apparmor_audit_data *ad = aad(sa);
75 
76 	if (address_family_names[sa->u.net->family])
77 		audit_log_format(ab, " family=\"%s\"",
78 				 address_family_names[sa->u.net->family]);
79 	else
80 		audit_log_format(ab, " family=\"unknown(%d)\"",
81 				 sa->u.net->family);
82 	if (sock_type_names[ad->net.type])
83 		audit_log_format(ab, " sock_type=\"%s\"",
84 				 sock_type_names[ad->net.type]);
85 	else
86 		audit_log_format(ab, " sock_type=\"unknown(%d)\"",
87 				 ad->net.type);
88 	audit_log_format(ab, " protocol=%d", ad->net.protocol);
89 
90 	if (ad->request & NET_PERMS_MASK) {
91 		audit_log_format(ab, " requested_mask=");
92 		aa_audit_perm_mask(ab, ad->request, NULL, 0,
93 				   net_mask_names, NET_PERMS_MASK);
94 
95 		if (ad->denied & NET_PERMS_MASK) {
96 			audit_log_format(ab, " denied_mask=");
97 			aa_audit_perm_mask(ab, ad->denied, NULL, 0,
98 					   net_mask_names, NET_PERMS_MASK);
99 		}
100 	}
101 	if (ad->peer) {
102 		audit_log_format(ab, " peer=");
103 		aa_label_xaudit(ab, labels_ns(ad->label), ad->peer,
104 				FLAGS_NONE, GFP_ATOMIC);
105 	}
106 }
107 
108 /* Generic af perm */
109 int aa_profile_af_perm(struct aa_profile *profile,
110 		       struct apparmor_audit_data *ad, u32 request, u16 family,
111 		       int type)
112 {
113 	struct aa_ruleset *rules = list_first_entry(&profile->rules,
114 						    typeof(*rules), list);
115 	struct aa_perms perms = { };
116 	aa_state_t state;
117 	__be16 buffer[2];
118 
119 	AA_BUG(family >= AF_MAX);
120 	AA_BUG(type < 0 || type >= SOCK_MAX);
121 
122 	if (profile_unconfined(profile))
123 		return 0;
124 	state = RULE_MEDIATES(rules, AA_CLASS_NET);
125 	if (!state)
126 		return 0;
127 
128 	buffer[0] = cpu_to_be16(family);
129 	buffer[1] = cpu_to_be16((u16) type);
130 	state = aa_dfa_match_len(rules->policy.dfa, state, (char *) &buffer,
131 				 4);
132 	perms = *aa_lookup_perms(&rules->policy, state);
133 	aa_apply_modes_to_perms(profile, &perms);
134 
135 	return aa_check_perms(profile, &perms, request, ad, audit_net_cb);
136 }
137 
138 int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family,
139 	       int type, int protocol)
140 {
141 	struct aa_profile *profile;
142 	DEFINE_AUDIT_NET(ad, op, NULL, family, type, protocol);
143 
144 	return fn_for_each_confined(label, profile,
145 			aa_profile_af_perm(profile, &ad, request, family,
146 					   type));
147 }
148 
149 static int aa_label_sk_perm(struct aa_label *label, const char *op, u32 request,
150 			    struct sock *sk)
151 {
152 	struct aa_sk_ctx *ctx = SK_CTX(sk);
153 	int error = 0;
154 
155 	AA_BUG(!label);
156 	AA_BUG(!sk);
157 
158 	if (ctx->label != kernel_t && !unconfined(label)) {
159 		struct aa_profile *profile;
160 		DEFINE_AUDIT_SK(ad, op, sk);
161 
162 		error = fn_for_each_confined(label, profile,
163 			    aa_profile_af_sk_perm(profile, &ad, request, sk));
164 	}
165 
166 	return error;
167 }
168 
169 int aa_sk_perm(const char *op, u32 request, struct sock *sk)
170 {
171 	struct aa_label *label;
172 	int error;
173 
174 	AA_BUG(!sk);
175 	AA_BUG(in_interrupt());
176 
177 	/* TODO: switch to begin_current_label ???? */
178 	label = begin_current_label_crit_section();
179 	error = aa_label_sk_perm(label, op, request, sk);
180 	end_current_label_crit_section(label);
181 
182 	return error;
183 }
184 
185 
186 int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request,
187 		      struct socket *sock)
188 {
189 	AA_BUG(!label);
190 	AA_BUG(!sock);
191 	AA_BUG(!sock->sk);
192 
193 	return aa_label_sk_perm(label, op, request, sock->sk);
194 }
195 
196 #ifdef CONFIG_NETWORK_SECMARK
197 static int apparmor_secmark_init(struct aa_secmark *secmark)
198 {
199 	struct aa_label *label;
200 
201 	if (secmark->label[0] == '*') {
202 		secmark->secid = AA_SECID_WILDCARD;
203 		return 0;
204 	}
205 
206 	label = aa_label_strn_parse(&root_ns->unconfined->label,
207 				    secmark->label, strlen(secmark->label),
208 				    GFP_ATOMIC, false, false);
209 
210 	if (IS_ERR(label))
211 		return PTR_ERR(label);
212 
213 	secmark->secid = label->secid;
214 
215 	return 0;
216 }
217 
218 static int aa_secmark_perm(struct aa_profile *profile, u32 request, u32 secid,
219 			   struct apparmor_audit_data *ad)
220 {
221 	int i, ret;
222 	struct aa_perms perms = { };
223 	struct aa_ruleset *rules = list_first_entry(&profile->rules,
224 						    typeof(*rules), list);
225 
226 	if (rules->secmark_count == 0)
227 		return 0;
228 
229 	for (i = 0; i < rules->secmark_count; i++) {
230 		if (!rules->secmark[i].secid) {
231 			ret = apparmor_secmark_init(&rules->secmark[i]);
232 			if (ret)
233 				return ret;
234 		}
235 
236 		if (rules->secmark[i].secid == secid ||
237 		    rules->secmark[i].secid == AA_SECID_WILDCARD) {
238 			if (rules->secmark[i].deny)
239 				perms.deny = ALL_PERMS_MASK;
240 			else
241 				perms.allow = ALL_PERMS_MASK;
242 
243 			if (rules->secmark[i].audit)
244 				perms.audit = ALL_PERMS_MASK;
245 		}
246 	}
247 
248 	aa_apply_modes_to_perms(profile, &perms);
249 
250 	return aa_check_perms(profile, &perms, request, ad, audit_net_cb);
251 }
252 
253 int apparmor_secmark_check(struct aa_label *label, char *op, u32 request,
254 			   u32 secid, const struct sock *sk)
255 {
256 	struct aa_profile *profile;
257 	DEFINE_AUDIT_SK(ad, op, sk);
258 
259 	return fn_for_each_confined(label, profile,
260 				    aa_secmark_perm(profile, request, secid,
261 						    &ad));
262 }
263 #endif
264