xref: /linux/security/apparmor/net.c (revision b58b13f156c00c2457035b7071eaaac105fe6836)
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->subj_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(const struct cred *subj_cred, struct aa_label *label,
139 	       const char *op, u32 request, u16 family, 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(const struct cred *subj_cred,
150 			    struct aa_label *label,
151 			    const char *op, u32 request,
152 			    struct sock *sk)
153 {
154 	struct aa_sk_ctx *ctx = SK_CTX(sk);
155 	int error = 0;
156 
157 	AA_BUG(!label);
158 	AA_BUG(!sk);
159 
160 	if (ctx->label != kernel_t && !unconfined(label)) {
161 		struct aa_profile *profile;
162 		DEFINE_AUDIT_SK(ad, op, sk);
163 
164 		ad.subj_cred = subj_cred;
165 		error = fn_for_each_confined(label, profile,
166 			    aa_profile_af_sk_perm(profile, &ad, request, sk));
167 	}
168 
169 	return error;
170 }
171 
172 int aa_sk_perm(const char *op, u32 request, struct sock *sk)
173 {
174 	struct aa_label *label;
175 	int error;
176 
177 	AA_BUG(!sk);
178 	AA_BUG(in_interrupt());
179 
180 	/* TODO: switch to begin_current_label ???? */
181 	label = begin_current_label_crit_section();
182 	error = aa_label_sk_perm(current_cred(), label, op, request, sk);
183 	end_current_label_crit_section(label);
184 
185 	return error;
186 }
187 
188 
189 int aa_sock_file_perm(const struct cred *subj_cred, struct aa_label *label,
190 		      const char *op, u32 request, struct socket *sock)
191 {
192 	AA_BUG(!label);
193 	AA_BUG(!sock);
194 	AA_BUG(!sock->sk);
195 
196 	return aa_label_sk_perm(subj_cred, label, op, request, sock->sk);
197 }
198 
199 #ifdef CONFIG_NETWORK_SECMARK
200 static int apparmor_secmark_init(struct aa_secmark *secmark)
201 {
202 	struct aa_label *label;
203 
204 	if (secmark->label[0] == '*') {
205 		secmark->secid = AA_SECID_WILDCARD;
206 		return 0;
207 	}
208 
209 	label = aa_label_strn_parse(&root_ns->unconfined->label,
210 				    secmark->label, strlen(secmark->label),
211 				    GFP_ATOMIC, false, false);
212 
213 	if (IS_ERR(label))
214 		return PTR_ERR(label);
215 
216 	secmark->secid = label->secid;
217 
218 	return 0;
219 }
220 
221 static int aa_secmark_perm(struct aa_profile *profile, u32 request, u32 secid,
222 			   struct apparmor_audit_data *ad)
223 {
224 	int i, ret;
225 	struct aa_perms perms = { };
226 	struct aa_ruleset *rules = list_first_entry(&profile->rules,
227 						    typeof(*rules), list);
228 
229 	if (rules->secmark_count == 0)
230 		return 0;
231 
232 	for (i = 0; i < rules->secmark_count; i++) {
233 		if (!rules->secmark[i].secid) {
234 			ret = apparmor_secmark_init(&rules->secmark[i]);
235 			if (ret)
236 				return ret;
237 		}
238 
239 		if (rules->secmark[i].secid == secid ||
240 		    rules->secmark[i].secid == AA_SECID_WILDCARD) {
241 			if (rules->secmark[i].deny)
242 				perms.deny = ALL_PERMS_MASK;
243 			else
244 				perms.allow = ALL_PERMS_MASK;
245 
246 			if (rules->secmark[i].audit)
247 				perms.audit = ALL_PERMS_MASK;
248 		}
249 	}
250 
251 	aa_apply_modes_to_perms(profile, &perms);
252 
253 	return aa_check_perms(profile, &perms, request, ad, audit_net_cb);
254 }
255 
256 int apparmor_secmark_check(struct aa_label *label, char *op, u32 request,
257 			   u32 secid, const struct sock *sk)
258 {
259 	struct aa_profile *profile;
260 	DEFINE_AUDIT_SK(ad, op, sk);
261 
262 	return fn_for_each_confined(label, profile,
263 				    aa_secmark_perm(profile, request, secid,
264 						    &ad));
265 }
266 #endif
267