xref: /xnu-12377.41.6/bsd/netinet6/nd6_send.c (revision bbb1b6f9e71b8cdde6e5cd6f4841f207dee3d828)
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 <net/if.h>
36 
37 #include <netinet/in.h>
38 #include <netinet6/in6_var.h>
39 #include <netinet/ip6.h>
40 #include <netinet6/ip6_var.h>
41 #include <netinet6/nd6.h>
42 
43 #if CONFIG_MACF
44 #include <sys/kauth.h>
45 #include <security/mac_framework.h>
46 #endif
47 
48 SYSCTL_DECL(_net_inet6);        /* Note: Not in any common header. */
49 
50 SYSCTL_NODE(_net_inet6, OID_AUTO, send, CTLFLAG_RW | CTLFLAG_LOCKED, 0,
51     "IPv6 Secure Neighbor Discovery");
52 
53 static int nd6_send_opmode = ND6_SEND_OPMODE_CGA_QUIET;
54 SYSCTL_INT(_net_inet6_send, OID_AUTO, opmode, CTLFLAG_RW | CTLFLAG_LOCKED,
55     &nd6_send_opmode, 0, "configured SEND operating mode");
56 
57 int nd6_send_opstate = ND6_SEND_OPMODE_DISABLED;
58 SYSCTL_INT(_net_inet6_send, OID_AUTO, opstate, CTLFLAG_RD | CTLFLAG_LOCKED,
59     &nd6_send_opstate, 0, "current SEND operating state");
60 
61 static int sysctl_cga_parameters SYSCTL_HANDLER_ARGS;
62 
63 SYSCTL_PROC(_net_inet6_send, OID_AUTO, cga_parameters,
64     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_LOCKED, 0, 0,
65     sysctl_cga_parameters, "S,nd6_send_nodecfg", "");
66 
67 /*
68  * The size of the buffer is sufficient to contain a public key, its size in
69  * machine binary type for the kernel, and the CGA precalc for the global
70  * scope. This interface is not a public API, so we don't anticipate that the
71  * userland and the kernel will be mismatched between ILP32 and LP64.
72  */
73 #define SYSCTL_CGA_PARAMETERS_BUFFER_SIZE \
74 	(2 * (sizeof (u_int16_t) + IN6_CGA_KEY_MAXSIZE) + \
75 	sizeof (struct in6_cga_prepare))
76 
77 static int
78 sysctl_cga_parameters SYSCTL_HANDLER_ARGS
79 {
80 #pragma unused(oidp, arg1)
81 	u_int namelen;
82 	char *oldp, *newp;
83 	const char *fin;
84 	struct in6_cga_nodecfg cfg;
85 	struct iovec *__single iov;
86 	int error;
87 	char *buffer;
88 	u_int16_t u16;
89 
90 	namelen = arg2;
91 	if (namelen != 0) {
92 		log(LOG_ERR, "%s: name length err [len=%u]\n", __func__,
93 		    namelen);
94 		return EINVAL;
95 	}
96 
97 	if (req->newlen > SYSCTL_CGA_PARAMETERS_BUFFER_SIZE) {
98 		log(LOG_ERR, "%s: input buffer size error [len=%zu]\n",
99 		    __func__, req->newlen);
100 		return EINVAL;
101 	}
102 
103 #if CONFIG_MACF
104 	error = mac_system_check_info(current_cached_proc_cred(req->p),
105 	    "net.inet6.send.cga_parameters");
106 	if (error != 0) {
107 		log(LOG_ERR, "%s: mac_system_check_info denied.\n", __func__);
108 		return EPERM;
109 	}
110 #endif
111 
112 	buffer = (char *)kalloc_data(SYSCTL_CGA_PARAMETERS_BUFFER_SIZE,
113 	    Z_WAITOK | Z_ZERO);
114 	if (buffer == NULL) {
115 		log(LOG_ERR, "%s: could not allocate marshaling buffer.\n",
116 		    __func__);
117 		return ENOMEM;
118 	}
119 
120 	in6_cga_node_lock();
121 
122 	if (req->oldptr != USER_ADDR_NULL && req->oldlen > 0) {
123 		oldp = buffer;
124 		fin = &buffer[SYSCTL_CGA_PARAMETERS_BUFFER_SIZE];
125 		if (req->oldlen < SYSCTL_CGA_PARAMETERS_BUFFER_SIZE) {
126 			fin = &buffer[req->oldlen];
127 		}
128 
129 		in6_cga_query(&cfg);
130 		iov = &cfg.cga_pubkey;
131 		if (iov->iov_len > 0) {
132 			VERIFY(iov->iov_len < UINT16_MAX);
133 
134 			if (&oldp[sizeof(cfg.cga_prepare)] <= fin) {
135 				bcopy(&cfg.cga_prepare, oldp,
136 				    sizeof(cfg.cga_prepare));
137 			}
138 			oldp += sizeof(cfg.cga_prepare);
139 
140 			if (&oldp[sizeof(u16)] < fin) {
141 				u16 = (u_int16_t) iov->iov_len;
142 				bcopy(&u16, oldp, sizeof(u16));
143 			}
144 			oldp += sizeof(u16);
145 
146 			if (&oldp[iov->iov_len] < fin) {
147 				bcopy(__unsafe_forge_bidi_indexable(void *, iov->iov_base, iov->iov_len), oldp, iov->iov_len);
148 			}
149 			oldp += iov->iov_len;
150 
151 			if (oldp > fin) {
152 				req->oldlen = oldp - buffer;
153 				log(LOG_ERR, "%s: marshalled data too large.\n",
154 				    __func__);
155 				error = ENOMEM;
156 				goto done;
157 			}
158 		}
159 
160 		error = SYSCTL_OUT(req, buffer, oldp - buffer);
161 		if (error) {
162 			goto done;
163 		}
164 	}
165 
166 	if (req->newptr == USER_ADDR_NULL) {
167 		goto done;
168 	}
169 
170 	error = proc_suser(current_proc());
171 	if (error) {
172 		goto done;
173 	}
174 
175 	if (req->newlen == 0) {
176 		in6_cga_stop();
177 		nd6_send_opstate = ND6_SEND_OPMODE_DISABLED;
178 		goto done;
179 	}
180 
181 	error = SYSCTL_IN(req, buffer, req->newlen);
182 	if (error) {
183 		goto done;
184 	}
185 
186 	newp = buffer;
187 	fin = &buffer[req->newlen];
188 
189 	bzero(&cfg, sizeof cfg);
190 
191 	if (&newp[sizeof(cfg.cga_prepare)] <= fin) {
192 		bcopy(newp, &cfg.cga_prepare, sizeof(cfg.cga_prepare));
193 	}
194 	newp += sizeof(cfg.cga_prepare);
195 
196 	iov = &cfg.cga_privkey;
197 	if (&newp[sizeof(u16)] < fin) {
198 		bcopy(newp, &u16, sizeof(u16));
199 		iov->iov_len = u16;
200 
201 		if (iov->iov_len > IN6_CGA_KEY_MAXSIZE) {
202 			error = EINVAL;
203 			goto done;
204 		}
205 	}
206 	newp += sizeof(u16);
207 
208 	iov->iov_base = newp;
209 	newp += iov->iov_len;
210 
211 	iov = &cfg.cga_pubkey;
212 	if (&newp[sizeof(u16)] < fin) {
213 		bcopy(newp, &u16, sizeof(u16));
214 		iov->iov_len = u16;
215 
216 		if (iov->iov_len > IN6_CGA_KEY_MAXSIZE) {
217 			error = EINVAL;
218 			goto done;
219 		}
220 	}
221 	newp += sizeof(u16);
222 
223 	iov->iov_base = newp;
224 	newp += iov->iov_len;
225 
226 	if (newp > fin) {
227 		log(LOG_ERR, "%s: input too large [octets=%ld].\n", __func__,
228 		    newp - fin);
229 		error = ENOMEM;
230 		goto done;
231 	}
232 
233 	error = in6_cga_start(&cfg);
234 	if (!error) {
235 		nd6_send_opstate = nd6_send_opmode;
236 	} else {
237 		log(LOG_ERR, "%s: in6_cga_start error=%d.\n", __func__,
238 		    error);
239 	}
240 
241 done:
242 	in6_cga_node_unlock();
243 	kfree_data(buffer, SYSCTL_CGA_PARAMETERS_BUFFER_SIZE);
244 	return error;
245 }
246 
247 /* End of file */
248