xref: /xnu-8796.101.5/bsd/netinet6/nd6_send.c (revision aca3beaa3dfbd42498b42c5e5ce20a938e6554e5) !
1 /*
2  * Copyright (c) 2013-2021 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 #include <sys/types.h>
30 #include <sys/malloc.h>
31 #include <sys/proc.h>
32 #include <sys/sysctl.h>
33 #include <sys/syslog.h>
34 
35 #include <libkern/crypto/sha1.h>
36 
37 #include <net/if.h>
38 
39 #include <netinet/in.h>
40 #include <netinet6/in6_var.h>
41 #include <netinet/ip6.h>
42 #include <netinet6/ip6_var.h>
43 #include <netinet6/nd6.h>
44 
45 #if CONFIG_MACF
46 #include <sys/kauth.h>
47 #include <security/mac_framework.h>
48 #endif
49 
50 SYSCTL_DECL(_net_inet6);        /* Note: Not in any common header. */
51 
52 SYSCTL_NODE(_net_inet6, OID_AUTO, send, CTLFLAG_RW | CTLFLAG_LOCKED, 0,
53     "IPv6 Secure Neighbor Discovery");
54 
55 static int nd6_send_opmode = ND6_SEND_OPMODE_CGA_QUIET;
56 SYSCTL_INT(_net_inet6_send, OID_AUTO, opmode, CTLFLAG_RW | CTLFLAG_LOCKED,
57     &nd6_send_opmode, 0, "configured SEND operating mode");
58 
59 int nd6_send_opstate = ND6_SEND_OPMODE_DISABLED;
60 SYSCTL_INT(_net_inet6_send, OID_AUTO, opstate, CTLFLAG_RD | CTLFLAG_LOCKED,
61     &nd6_send_opstate, 0, "current SEND operating state");
62 
63 static int sysctl_cga_parameters SYSCTL_HANDLER_ARGS;
64 
65 SYSCTL_PROC(_net_inet6_send, OID_AUTO, cga_parameters,
66     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_LOCKED, 0, 0,
67     sysctl_cga_parameters, "S,nd6_send_nodecfg", "");
68 
69 /*
70  * The size of the buffer is sufficient to contain a public key, its size in
71  * machine binary type for the kernel, and the CGA precalc for the global
72  * scope. This interface is not a public API, so we don't anticipate that the
73  * userland and the kernel will be mismatched between ILP32 and LP64.
74  */
75 #define SYSCTL_CGA_PARAMETERS_BUFFER_SIZE \
76 	(2 * (sizeof (u_int16_t) + IN6_CGA_KEY_MAXSIZE) + \
77 	sizeof (struct in6_cga_prepare))
78 
79 static int
80 sysctl_cga_parameters SYSCTL_HANDLER_ARGS
81 {
82 #pragma unused(oidp, arg1)
83 	u_int namelen;
84 	char *oldp, *newp;
85 	const char *fin;
86 	struct in6_cga_nodecfg cfg;
87 	struct iovec *iov;
88 	int error;
89 	char *buffer;
90 	u_int16_t u16;
91 #if CONFIG_MACF
92 	kauth_cred_t cred;
93 #endif
94 
95 	namelen = arg2;
96 	if (namelen != 0) {
97 		log(LOG_ERR, "%s: name length err [len=%u]\n", __func__,
98 		    namelen);
99 		return EINVAL;
100 	}
101 
102 	if (req->newlen > SYSCTL_CGA_PARAMETERS_BUFFER_SIZE) {
103 		log(LOG_ERR, "%s: input buffer size error [len=%zu]\n",
104 		    __func__, req->newlen);
105 		return EINVAL;
106 	}
107 
108 #if CONFIG_MACF
109 	cred = kauth_cred_proc_ref(current_proc());
110 	error = mac_system_check_info(cred, "net.inet6.send.cga_parameters");
111 	kauth_cred_unref(&cred);
112 	if (error != 0) {
113 		log(LOG_ERR, "%s: mac_system_check_info denied.\n", __func__);
114 		return EPERM;
115 	}
116 #endif
117 
118 	buffer = (char *)kalloc_data(SYSCTL_CGA_PARAMETERS_BUFFER_SIZE,
119 	    Z_WAITOK | Z_ZERO);
120 	if (buffer == NULL) {
121 		log(LOG_ERR, "%s: could not allocate marshaling buffer.\n",
122 		    __func__);
123 		return ENOMEM;
124 	}
125 
126 	in6_cga_node_lock();
127 
128 	if (req->oldptr != USER_ADDR_NULL && req->oldlen > 0) {
129 		oldp = buffer;
130 		fin = &buffer[SYSCTL_CGA_PARAMETERS_BUFFER_SIZE];
131 		if (req->oldlen < SYSCTL_CGA_PARAMETERS_BUFFER_SIZE) {
132 			fin = &buffer[req->oldlen];
133 		}
134 
135 		in6_cga_query(&cfg);
136 		iov = &cfg.cga_pubkey;
137 		if (iov->iov_len > 0) {
138 			VERIFY(iov->iov_len < UINT16_MAX);
139 
140 			if (&oldp[sizeof(cfg.cga_prepare)] <= fin) {
141 				bcopy(&cfg.cga_prepare, oldp,
142 				    sizeof(cfg.cga_prepare));
143 			}
144 			oldp += sizeof(cfg.cga_prepare);
145 
146 			if (&oldp[sizeof(u16)] < fin) {
147 				u16 = (u_int16_t) iov->iov_len;
148 				bcopy(&u16, oldp, sizeof(u16));
149 			}
150 			oldp += sizeof(u16);
151 
152 			if (&oldp[iov->iov_len] < fin) {
153 				bcopy(iov->iov_base, oldp, iov->iov_len);
154 			}
155 			oldp += iov->iov_len;
156 
157 			if (oldp > fin) {
158 				req->oldlen = oldp - buffer;
159 				log(LOG_ERR, "%s: marshalled data too large.\n",
160 				    __func__);
161 				error = ENOMEM;
162 				goto done;
163 			}
164 		}
165 
166 		error = SYSCTL_OUT(req, buffer, oldp - buffer);
167 		if (error) {
168 			goto done;
169 		}
170 	}
171 
172 	if (req->newptr == USER_ADDR_NULL) {
173 		goto done;
174 	}
175 
176 	error = proc_suser(current_proc());
177 	if (error) {
178 		goto done;
179 	}
180 
181 	if (req->newlen == 0) {
182 		in6_cga_stop();
183 		nd6_send_opstate = ND6_SEND_OPMODE_DISABLED;
184 		goto done;
185 	}
186 
187 	error = SYSCTL_IN(req, buffer, req->newlen);
188 	if (error) {
189 		goto done;
190 	}
191 
192 	newp = buffer;
193 	fin = &buffer[req->newlen];
194 
195 	bzero(&cfg, sizeof cfg);
196 
197 	if (&newp[sizeof(cfg.cga_prepare)] <= fin) {
198 		bcopy(newp, &cfg.cga_prepare, sizeof(cfg.cga_prepare));
199 	}
200 	newp += sizeof(cfg.cga_prepare);
201 
202 	iov = &cfg.cga_privkey;
203 	if (&newp[sizeof(u16)] < fin) {
204 		bcopy(newp, &u16, sizeof(u16));
205 		iov->iov_len = u16;
206 
207 		if (iov->iov_len > IN6_CGA_KEY_MAXSIZE) {
208 			error = EINVAL;
209 			goto done;
210 		}
211 	}
212 	newp += sizeof(u16);
213 
214 	iov->iov_base = newp;
215 	newp += iov->iov_len;
216 
217 	iov = &cfg.cga_pubkey;
218 	if (&newp[sizeof(u16)] < fin) {
219 		bcopy(newp, &u16, sizeof(u16));
220 		iov->iov_len = u16;
221 
222 		if (iov->iov_len > IN6_CGA_KEY_MAXSIZE) {
223 			error = EINVAL;
224 			goto done;
225 		}
226 	}
227 	newp += sizeof(u16);
228 
229 	iov->iov_base = newp;
230 	newp += iov->iov_len;
231 
232 	if (newp > fin) {
233 		log(LOG_ERR, "%s: input too large [octets=%ld].\n", __func__,
234 		    newp - fin);
235 		error = ENOMEM;
236 		goto done;
237 	}
238 
239 	error = in6_cga_start(&cfg);
240 	if (!error) {
241 		nd6_send_opstate = nd6_send_opmode;
242 	} else {
243 		log(LOG_ERR, "%s: in6_cga_start error=%d.\n", __func__,
244 		    error);
245 	}
246 
247 done:
248 	in6_cga_node_unlock();
249 	kfree_data(buffer, SYSCTL_CGA_PARAMETERS_BUFFER_SIZE);
250 	return error;
251 }
252 
253 /* End of file */
254