xref: /linux/security/apparmor/net.c (revision fbf46565c67c626849c7ce2a326972d3008d2a91)
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_ruleset *rules = list_first_entry(&profile->rules,
112 						    typeof(*rules), list);
113 	struct aa_perms perms = { };
114 	aa_state_t state;
115 	__be16 buffer[2];
116 
117 	AA_BUG(family >= AF_MAX);
118 	AA_BUG(type < 0 || type >= SOCK_MAX);
119 
120 	if (profile_unconfined(profile))
121 		return 0;
122 	state = RULE_MEDIATES(rules, AA_CLASS_NET);
123 	if (!state)
124 		return 0;
125 
126 	buffer[0] = cpu_to_be16(family);
127 	buffer[1] = cpu_to_be16((u16) type);
128 	state = aa_dfa_match_len(rules->policy.dfa, state, (char *) &buffer,
129 				 4);
130 	perms = *aa_lookup_perms(&rules->policy, state);
131 	aa_apply_modes_to_perms(profile, &perms);
132 
133 	return aa_check_perms(profile, &perms, request, sa, audit_net_cb);
134 }
135 
136 int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family,
137 	       int type, int protocol)
138 {
139 	struct aa_profile *profile;
140 	DEFINE_AUDIT_NET(sa, op, NULL, family, type, protocol);
141 
142 	return fn_for_each_confined(label, profile,
143 			aa_profile_af_perm(profile, &sa, request, family,
144 					   type));
145 }
146 
147 static int aa_label_sk_perm(struct aa_label *label, const char *op, u32 request,
148 			    struct sock *sk)
149 {
150 	struct aa_sk_ctx *ctx = SK_CTX(sk);
151 	int error = 0;
152 
153 	AA_BUG(!label);
154 	AA_BUG(!sk);
155 
156 	if (ctx->label != kernel_t && !unconfined(label)) {
157 		struct aa_profile *profile;
158 		DEFINE_AUDIT_SK(sa, op, sk);
159 
160 		error = fn_for_each_confined(label, profile,
161 			    aa_profile_af_sk_perm(profile, &sa, request, sk));
162 	}
163 
164 	return error;
165 }
166 
167 int aa_sk_perm(const char *op, u32 request, struct sock *sk)
168 {
169 	struct aa_label *label;
170 	int error;
171 
172 	AA_BUG(!sk);
173 	AA_BUG(in_interrupt());
174 
175 	/* TODO: switch to begin_current_label ???? */
176 	label = begin_current_label_crit_section();
177 	error = aa_label_sk_perm(label, op, request, sk);
178 	end_current_label_crit_section(label);
179 
180 	return error;
181 }
182 
183 
184 int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request,
185 		      struct socket *sock)
186 {
187 	AA_BUG(!label);
188 	AA_BUG(!sock);
189 	AA_BUG(!sock->sk);
190 
191 	return aa_label_sk_perm(label, op, request, sock->sk);
192 }
193 
194 #ifdef CONFIG_NETWORK_SECMARK
195 static int apparmor_secmark_init(struct aa_secmark *secmark)
196 {
197 	struct aa_label *label;
198 
199 	if (secmark->label[0] == '*') {
200 		secmark->secid = AA_SECID_WILDCARD;
201 		return 0;
202 	}
203 
204 	label = aa_label_strn_parse(&root_ns->unconfined->label,
205 				    secmark->label, strlen(secmark->label),
206 				    GFP_ATOMIC, false, false);
207 
208 	if (IS_ERR(label))
209 		return PTR_ERR(label);
210 
211 	secmark->secid = label->secid;
212 
213 	return 0;
214 }
215 
216 static int aa_secmark_perm(struct aa_profile *profile, u32 request, u32 secid,
217 			   struct common_audit_data *sa)
218 {
219 	int i, ret;
220 	struct aa_perms perms = { };
221 	struct aa_ruleset *rules = list_first_entry(&profile->rules,
222 						    typeof(*rules), list);
223 
224 	if (rules->secmark_count == 0)
225 		return 0;
226 
227 	for (i = 0; i < rules->secmark_count; i++) {
228 		if (!rules->secmark[i].secid) {
229 			ret = apparmor_secmark_init(&rules->secmark[i]);
230 			if (ret)
231 				return ret;
232 		}
233 
234 		if (rules->secmark[i].secid == secid ||
235 		    rules->secmark[i].secid == AA_SECID_WILDCARD) {
236 			if (rules->secmark[i].deny)
237 				perms.deny = ALL_PERMS_MASK;
238 			else
239 				perms.allow = ALL_PERMS_MASK;
240 
241 			if (rules->secmark[i].audit)
242 				perms.audit = ALL_PERMS_MASK;
243 		}
244 	}
245 
246 	aa_apply_modes_to_perms(profile, &perms);
247 
248 	return aa_check_perms(profile, &perms, request, sa, audit_net_cb);
249 }
250 
251 int apparmor_secmark_check(struct aa_label *label, char *op, u32 request,
252 			   u32 secid, const struct sock *sk)
253 {
254 	struct aa_profile *profile;
255 	DEFINE_AUDIT_SK(sa, op, sk);
256 
257 	return fn_for_each_confined(label, profile,
258 				    aa_secmark_perm(profile, request, secid,
259 						    &sa));
260 }
261 #endif
262