xref: /linux/security/apparmor/net.c (revision 31354121bf03dac6498a4236928a38490745d601)
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 
75 	if (address_family_names[sa->u.net->family])
76 		audit_log_format(ab, " family=\"%s\"",
77 				 address_family_names[sa->u.net->family]);
78 	else
79 		audit_log_format(ab, " family=\"unknown(%d)\"",
80 				 sa->u.net->family);
81 	if (sock_type_names[aad(sa)->net.type])
82 		audit_log_format(ab, " sock_type=\"%s\"",
83 				 sock_type_names[aad(sa)->net.type]);
84 	else
85 		audit_log_format(ab, " sock_type=\"unknown(%d)\"",
86 				 aad(sa)->net.type);
87 	audit_log_format(ab, " protocol=%d", aad(sa)->net.protocol);
88 
89 	if (aad(sa)->request & NET_PERMS_MASK) {
90 		audit_log_format(ab, " requested_mask=");
91 		aa_audit_perm_mask(ab, aad(sa)->request, NULL, 0,
92 				   net_mask_names, NET_PERMS_MASK);
93 
94 		if (aad(sa)->denied & NET_PERMS_MASK) {
95 			audit_log_format(ab, " denied_mask=");
96 			aa_audit_perm_mask(ab, aad(sa)->denied, NULL, 0,
97 					   net_mask_names, NET_PERMS_MASK);
98 		}
99 	}
100 	if (aad(sa)->peer) {
101 		audit_log_format(ab, " peer=");
102 		aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
103 				FLAGS_NONE, GFP_ATOMIC);
104 	}
105 }
106 
107 /* Generic af perm */
108 int aa_profile_af_perm(struct aa_profile *profile, struct common_audit_data *sa,
109 		       u32 request, u16 family, int type)
110 {
111 	struct aa_perms perms = { };
112 	unsigned int state;
113 	__be16 buffer[2];
114 
115 	AA_BUG(family >= AF_MAX);
116 	AA_BUG(type < 0 || type >= SOCK_MAX);
117 
118 	if (profile_unconfined(profile))
119 		return 0;
120 	state = PROFILE_MEDIATES(profile, AA_CLASS_NET);
121 	if (!state)
122 		return 0;
123 
124 	buffer[0] = cpu_to_be16(family);
125 	buffer[1] = cpu_to_be16((u16) type);
126 	state = aa_dfa_match_len(profile->policy.dfa, state, (char *) &buffer,
127 				 4);
128 	aa_compute_perms(profile->policy.dfa, state, &perms);
129 	aa_apply_modes_to_perms(profile, &perms);
130 
131 	return aa_check_perms(profile, &perms, request, sa, audit_net_cb);
132 }
133 
134 int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family,
135 	       int type, int protocol)
136 {
137 	struct aa_profile *profile;
138 	DEFINE_AUDIT_NET(sa, op, NULL, family, type, protocol);
139 
140 	return fn_for_each_confined(label, profile,
141 			aa_profile_af_perm(profile, &sa, request, family,
142 					   type));
143 }
144 
145 static int aa_label_sk_perm(struct aa_label *label, const char *op, u32 request,
146 			    struct sock *sk)
147 {
148 	struct aa_sk_ctx *ctx = SK_CTX(sk);
149 	int error = 0;
150 
151 	AA_BUG(!label);
152 	AA_BUG(!sk);
153 
154 	if (ctx->label != kernel_t && !unconfined(label)) {
155 		struct aa_profile *profile;
156 		DEFINE_AUDIT_SK(sa, op, sk);
157 
158 		error = fn_for_each_confined(label, profile,
159 			    aa_profile_af_sk_perm(profile, &sa, request, sk));
160 	}
161 
162 	return error;
163 }
164 
165 int aa_sk_perm(const char *op, u32 request, struct sock *sk)
166 {
167 	struct aa_label *label;
168 	int error;
169 
170 	AA_BUG(!sk);
171 	AA_BUG(in_interrupt());
172 
173 	/* TODO: switch to begin_current_label ???? */
174 	label = begin_current_label_crit_section();
175 	error = aa_label_sk_perm(label, op, request, sk);
176 	end_current_label_crit_section(label);
177 
178 	return error;
179 }
180 
181 
182 int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request,
183 		      struct socket *sock)
184 {
185 	AA_BUG(!label);
186 	AA_BUG(!sock);
187 	AA_BUG(!sock->sk);
188 
189 	return aa_label_sk_perm(label, op, request, sock->sk);
190 }
191 
192 #ifdef CONFIG_NETWORK_SECMARK
193 static int apparmor_secmark_init(struct aa_secmark *secmark)
194 {
195 	struct aa_label *label;
196 
197 	if (secmark->label[0] == '*') {
198 		secmark->secid = AA_SECID_WILDCARD;
199 		return 0;
200 	}
201 
202 	label = aa_label_strn_parse(&root_ns->unconfined->label,
203 				    secmark->label, strlen(secmark->label),
204 				    GFP_ATOMIC, false, false);
205 
206 	if (IS_ERR(label))
207 		return PTR_ERR(label);
208 
209 	secmark->secid = label->secid;
210 
211 	return 0;
212 }
213 
214 static int aa_secmark_perm(struct aa_profile *profile, u32 request, u32 secid,
215 			   struct common_audit_data *sa)
216 {
217 	int i, ret;
218 	struct aa_perms perms = { };
219 
220 	if (profile->secmark_count == 0)
221 		return 0;
222 
223 	for (i = 0; i < profile->secmark_count; i++) {
224 		if (!profile->secmark[i].secid) {
225 			ret = apparmor_secmark_init(&profile->secmark[i]);
226 			if (ret)
227 				return ret;
228 		}
229 
230 		if (profile->secmark[i].secid == secid ||
231 		    profile->secmark[i].secid == AA_SECID_WILDCARD) {
232 			if (profile->secmark[i].deny)
233 				perms.deny = ALL_PERMS_MASK;
234 			else
235 				perms.allow = ALL_PERMS_MASK;
236 
237 			if (profile->secmark[i].audit)
238 				perms.audit = ALL_PERMS_MASK;
239 		}
240 	}
241 
242 	aa_apply_modes_to_perms(profile, &perms);
243 
244 	return aa_check_perms(profile, &perms, request, sa, audit_net_cb);
245 }
246 
247 int apparmor_secmark_check(struct aa_label *label, char *op, u32 request,
248 			   u32 secid, const struct sock *sk)
249 {
250 	struct aa_profile *profile;
251 	DEFINE_AUDIT_SK(sa, op, sk);
252 
253 	return fn_for_each_confined(label, profile,
254 				    aa_secmark_perm(profile, request, secid,
255 						    &sa));
256 }
257 #endif
258