1 /*
2  * dhcpcd - DHCP client daemon
3  * Copyright (c) 2006-2015 Roy Marples <roy@marples.name>
4  * All rights reserved
5 
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #ifndef IPV6_H
29 #define IPV6_H
30 
31 #include <sys/uio.h>
32 #include <netinet/in.h>
33 
34 #include "config.h"
35 #include "dhcpcd.h"
36 
37 #define ALLROUTERS "ff02::2"
38 
39 #define ROUNDUP8(a)  (1 + (((a) - 1) |  7))
40 #define ROUNDUP16(a) (1 + (((a) - 1) | 16))
41 
42 #define EUI64_GBIT		0x01
43 #define EUI64_UBIT		0x02
44 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
45 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
46 
47 #ifndef ND6_INFINITE_LIFETIME
48 #  define ND6_INFINITE_LIFETIME		((uint32_t)~0)
49 #endif
50 
51 /* RFC4941 constants */
52 #define TEMP_VALID_LIFETIME	604800	/* 1 week */
53 #define TEMP_PREFERRED_LIFETIME	86400	/* 1 day */
54 #define REGEN_ADVANCE		5	/* seconds */
55 #define MAX_DESYNC_FACTOR	600	/* 10 minutes */
56 
57 #define TEMP_IDGEN_RETRIES	3
58 #define GEN_TEMPID_RETRY_MAX	5
59 
60 /* RFC7217 constants */
61 #define IDGEN_RETRIES	3
62 #define IDGEN_DELAY	1 /* second */
63 
64 /*
65  * BSD kernels don't inform userland of DAD results.
66  * See the discussion here:
67  *    http://mail-index.netbsd.org/tech-net/2013/03/15/msg004019.html
68  */
69 #ifndef __linux__
70 /* We guard here to avoid breaking a compile on linux ppc-64 headers */
71 #  include <sys/param.h>
72 #endif
73 #ifdef BSD
74 #  define IPV6_POLLADDRFLAG
75 #endif
76 
77 /* This was fixed in NetBSD */
78 #if defined(__NetBSD_Version__) && __NetBSD_Version__ >= 699002000
79 #  undef IPV6_POLLADDRFLAG
80 #endif
81 
82 /* Linux-3.18 can manage temporary addresses even with RA
83  * processing disabled. */
84 //#undef IFA_F_MANAGETEMPADDR
85 #if defined(__linux__) && defined(IFA_F_MANAGETEMPADDR)
86 #define IPV6_MANAGETEMPADDR
87 #endif
88 
89 /* Some BSDs do not allow userland to set temporary addresses. */
90 #if defined(BSD) && defined(IN6_IFF_TEMPORARY)
91 #define IPV6_MANAGETEMPADDR
92 #endif
93 
94 struct ipv6_addr {
95 	TAILQ_ENTRY(ipv6_addr) next;
96 	struct interface *iface;
97 	struct in6_addr prefix;
98 	uint8_t prefix_len;
99 	uint32_t prefix_vltime;
100 	uint32_t prefix_pltime;
101 	struct timespec created;
102 	struct timespec acquired;
103 	struct in6_addr addr;
104 	int addr_flags;
105 	short flags;
106 	char saddr[INET6_ADDRSTRLEN];
107 	uint8_t iaid[4];
108 	uint16_t ia_type;
109 	struct interface *delegating_iface;
110 	uint8_t prefix_exclude_len;
111 	struct in6_addr prefix_exclude;
112 
113 	void (*dadcallback)(void *);
114 	int dadcounter;
115 	uint8_t *ns;
116 	size_t nslen;
117 	int nsprobes;
118 };
119 TAILQ_HEAD(ipv6_addrhead, ipv6_addr);
120 
121 #define IPV6_AF_ONLINK		0x0001
122 #define	IPV6_AF_NEW		0x0002
123 #define IPV6_AF_STALE		0x0004
124 #define IPV6_AF_ADDED		0x0008
125 #define IPV6_AF_AUTOCONF	0x0010
126 #define IPV6_AF_DUPLICATED	0x0020
127 #define IPV6_AF_DADCOMPLETED	0x0040
128 #define IPV6_AF_DELEGATED	0x0080
129 #define IPV6_AF_DELEGATEDPFX	0x0100
130 #define IPV6_AF_DELEGATEDZERO	0x0200
131 #define IPV6_AF_REQUEST		0x0400
132 #ifdef IPV6_MANAGETEMPADDR
133 #define IPV6_AF_TEMPORARY	0X0800
134 #endif
135 
136 struct rt6 {
137 	TAILQ_ENTRY(rt6) next;
138 	struct in6_addr dest;
139 	struct in6_addr net;
140 	struct in6_addr gate;
141 	const struct interface *iface;
142 	unsigned int flags;
143 #ifdef HAVE_ROUTE_METRIC
144 	unsigned int metric;
145 #endif
146 	unsigned int mtu;
147 };
148 TAILQ_HEAD(rt6_head, rt6);
149 
150 struct ll_callback {
151 	TAILQ_ENTRY(ll_callback) next;
152 	void (*callback)(void *);
153 	void *arg;
154 };
155 TAILQ_HEAD(ll_callback_head, ll_callback);
156 
157 struct ipv6_state {
158 	struct ipv6_addrhead addrs;
159 	struct ll_callback_head ll_callbacks;
160 
161 #ifdef IPV6_MANAGETEMPADDR
162 	time_t desync_factor;
163 	uint8_t randomseed0[8]; /* upper 64 bits of MD5 digest */
164 	uint8_t randomseed1[8]; /* lower 64 bits */
165 	uint8_t randomid[8];
166 #endif
167 };
168 
169 #define IPV6_STATE(ifp)							       \
170 	((struct ipv6_state *)(ifp)->if_data[IF_DATA_IPV6])
171 #define IPV6_CSTATE(ifp)						       \
172 	((const struct ipv6_state *)(ifp)->if_data[IF_DATA_IPV6])
173 
174 /* dhcpcd requires CMSG_SPACE to evaluate to a compile time constant. */
175 #ifdef __QNX__
176 #undef CMSG_SPACE
177 #endif
178 
179 #ifndef ALIGNBYTES
180 #define ALIGNBYTES (sizeof(int) - 1)
181 #endif
182 #ifndef ALIGN
183 #define	ALIGN(p) (((unsigned int)(p) + ALIGNBYTES) & ~ALIGNBYTES)
184 #endif
185 #ifndef CMSG_SPACE
186 #define	CMSG_SPACE(len)	(ALIGN(sizeof(struct cmsghdr)) + ALIGN(len))
187 #endif
188 
189 #define IP6BUFLEN	(CMSG_SPACE(sizeof(struct in6_pktinfo)) + \
190 			CMSG_SPACE(sizeof(int)))
191 
192 
193 #ifdef INET6
194 struct ipv6_ctx {
195 	struct sockaddr_in6 from;
196 	struct msghdr sndhdr;
197 	struct iovec sndiov[2];
198 	unsigned char sndbuf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
199 	struct msghdr rcvhdr;
200 	struct iovec rcviov[2];
201 	unsigned char rcvbuf[IP6BUFLEN];
202 	unsigned char ansbuf[1500];
203 	char ntopbuf[INET6_ADDRSTRLEN];
204 	const char *sfrom;
205 
206 	int nd_fd;
207 	struct ra_head *ra_routers;
208 	struct rt6_head *routes;
209 
210 	struct rt6_head kroutes;
211 
212 	int dhcp_fd;
213 };
214 
215 struct ipv6_ctx *ipv6_init(struct dhcpcd_ctx *);
216 ssize_t ipv6_printaddr(char *, size_t, const uint8_t *, const char *);
217 int ipv6_makestableprivate(struct in6_addr *addr,
218     const struct in6_addr *prefix, int prefix_len,
219     const struct interface *ifp, int *dad_counter);
220 int ipv6_makeaddr(struct in6_addr *, const struct interface *,
221     const struct in6_addr *, int);
222 int ipv6_makeprefix(struct in6_addr *, const struct in6_addr *, int);
223 int ipv6_mask(struct in6_addr *, int);
224 uint8_t ipv6_prefixlen(const struct in6_addr *);
225 int ipv6_userprefix( const struct in6_addr *, short prefix_len,
226     uint64_t user_number, struct in6_addr *result, short result_len);
227 void ipv6_checkaddrflags(void *);
228 int ipv6_addaddr(struct ipv6_addr *, const struct timespec *);
229 ssize_t ipv6_addaddrs(struct ipv6_addrhead *addrs);
230 void ipv6_freedrop_addrs(struct ipv6_addrhead *, int,
231     const struct interface *);
232 void ipv6_handleifa(struct dhcpcd_ctx *ctx, int, struct if_head *,
233     const char *, const struct in6_addr *, uint8_t, int);
234 int ipv6_handleifa_addrs(int, struct ipv6_addrhead *,
235     const struct in6_addr *, int);
236 int ipv6_publicaddr(const struct ipv6_addr *);
237 const struct ipv6_addr *ipv6_iffindaddr(const struct interface *,
238     const struct in6_addr *);
239 struct ipv6_addr *ipv6_findaddr(struct dhcpcd_ctx *,
240     const struct in6_addr *, short);
241 #define ipv6_linklocal(ifp) ipv6_iffindaddr((ifp), NULL)
242 int ipv6_addlinklocalcallback(struct interface *, void (*)(void *), void *);
243 void ipv6_freeaddr(struct ipv6_addr *);
244 void ipv6_freedrop(struct interface *, int);
245 #define ipv6_free(ifp) ipv6_freedrop((ifp), 0)
246 #define ipv6_drop(ifp) ipv6_freedrop((ifp), 2)
247 
248 #ifdef IPV6_MANAGETEMPADDR
249 void ipv6_gentempifid(struct interface *);
250 void ipv6_settempstale(struct interface *);
251 struct ipv6_addr *ipv6_createtempaddr(struct ipv6_addr *,
252     const struct timespec *);
253 struct ipv6_addr *ipv6_settemptime(struct ipv6_addr *, int);
254 void ipv6_addtempaddrs(struct interface *, const struct timespec *);
255 #else
256 #define ipv6_gentempifid(a) {}
257 #define ipv6_settempstale(a) {}
258 #endif
259 
260 int ipv6_start(struct interface *);
261 void ipv6_ctxfree(struct dhcpcd_ctx *);
262 int ipv6_handlert(struct dhcpcd_ctx *, int cmd, struct rt6 *);
263 void ipv6_freerts(struct rt6_head *);
264 void ipv6_buildroutes(struct dhcpcd_ctx *);
265 
266 #else
267 #define ipv6_init(a) (NULL)
268 #define ipv6_start(a) (-1)
269 #define ipv6_free_ll_callbacks(a) {}
270 #define ipv6_free(a) {}
271 #define ipv6_drop(a) {}
272 #define ipv6_ctxfree(a) {}
273 #define ipv6_gentempifid(a) {}
274 #endif
275 
276 #endif
277