1 /*
2  * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA.
18  *
19  * You can also choose to distribute this program under the terms of
20  * the Unmodified Binary Distribution Licence (as given in the file
21  * COPYING.UBDL), provided that you have satisfied its requirements.
22  */
23 
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25 
26 #include <string.h>
27 #include <errno.h>
28 #include <byteswap.h>
29 #include <ipxe/in.h>
30 #include <ipxe/iobuf.h>
31 #include <ipxe/tcpip.h>
32 #include <ipxe/ping.h>
33 #include <ipxe/icmpv6.h>
34 
35 /** @file
36  *
37  * ICMPv6 protocol
38  *
39  */
40 
41 /* Disambiguate the various error causes */
42 #define EHOSTUNREACH_ROUTE						\
43 	__einfo_error ( EINFO_EHOSTUNREACH_ROUTE )
44 #define EINFO_EHOSTUNREACH_ROUTE					\
45 	__einfo_uniqify ( EINFO_EHOSTUNREACH, 0,			\
46 			  "No route to destination" )
47 #define EHOSTUNREACH_PROHIBITED						\
48 	__einfo_error ( EINFO_EHOSTUNREACH_PROHIBITED )
49 #define EINFO_EHOSTUNREACH_PROHIBITED					\
50 	__einfo_uniqify ( EINFO_EHOSTUNREACH, 1,			\
51 			  "Communication administratively prohibited" )
52 #define EHOSTUNREACH_ADDRESS						\
53 	__einfo_error ( EINFO_EHOSTUNREACH_ADDRESS )
54 #define EINFO_EHOSTUNREACH_ADDRESS					\
55 	__einfo_uniqify ( EINFO_EHOSTUNREACH, 3,			\
56 			  "Address unreachable" )
57 #define EHOSTUNREACH_PORT						\
58 	__einfo_error ( EINFO_EHOSTUNREACH_PORT )
59 #define EINFO_EHOSTUNREACH_PORT						\
60 	__einfo_uniqify ( EINFO_EHOSTUNREACH, 4,			\
61 			  "Port unreachable" )
62 #define EHOSTUNREACH_CODE( code )					\
63 	EUNIQ ( EINFO_EHOSTUNREACH, ( (code) & 0x1f ),			\
64 		EHOSTUNREACH_ROUTE, EHOSTUNREACH_PROHIBITED,		\
65 		EHOSTUNREACH_ADDRESS, EHOSTUNREACH_PORT )
66 
67 #define ETIMEDOUT_HOP							\
68 	__einfo_error ( EINFO_ETIMEDOUT_HOP )
69 #define EINFO_ETIMEDOUT_HOP						\
70 	__einfo_uniqify ( EINFO_ETIMEDOUT, 0,				\
71 			  "Hop limit exceeded in transit" )
72 #define ETIMEDOUT_REASSEMBLY						\
73 	__einfo_error ( EINFO_ETIMEDOUT_REASSEMBLY )
74 #define EINFO_ETIMEDOUT_REASSEMBLY					\
75 	__einfo_uniqify ( EINFO_ETIMEDOUT, 1,				\
76 			  "Fragment reassembly time exceeded" )
77 #define ETIMEDOUT_CODE( code )						\
78 	EUNIQ ( EINFO_ETIMEDOUT, ( (code) & 0x1f ),			\
79 		ETIMEDOUT_HOP, ETIMEDOUT_REASSEMBLY )
80 
81 #define EPROTO_BAD_HEADER						\
82 	__einfo_error ( EINFO_EPROTO_BAD_HEADER )
83 #define EINFO_EPROTO_BAD_HEADER						\
84 	__einfo_uniqify ( EINFO_EPROTO, 0,				\
85 			  "Erroneous header field" )
86 #define EPROTO_NEXT_HEADER						\
87 	__einfo_error ( EINFO_EPROTO_NEXT_HEADER )
88 #define EINFO_EPROTO_NEXT_HEADER					\
89 	__einfo_uniqify ( EINFO_EPROTO, 1,				\
90 			  "Unrecognised next header type" )
91 #define EPROTO_OPTION							\
92 	__einfo_error ( EINFO_EPROTO_OPTION )
93 #define EINFO_EPROTO_OPTION						\
94 	__einfo_uniqify ( EINFO_EPROTO, 2,				\
95 			  "Unrecognised IPv6 option" )
96 #define EPROTO_CODE( code )						\
97 	EUNIQ ( EINFO_EPROTO, ( (code) & 0x1f ),			\
98 		EPROTO_BAD_HEADER, EPROTO_NEXT_HEADER, EPROTO_OPTION )
99 
100 struct icmp_echo_protocol icmpv6_echo_protocol __icmp_echo_protocol;
101 
102 /**
103  * Process received ICMPv6 echo request packet
104  *
105  * @v iobuf		I/O buffer
106  * @v netdev		Network device
107  * @v sin6_src		Source socket address
108  * @v sin6_dest		Destination socket address
109  * @ret rc		Return status code
110  */
icmpv6_rx_echo_request(struct io_buffer * iobuf,struct net_device * netdev __unused,struct sockaddr_in6 * sin6_src,struct sockaddr_in6 * sin6_dest __unused)111 static int icmpv6_rx_echo_request ( struct io_buffer *iobuf,
112 				    struct net_device *netdev __unused,
113 				    struct sockaddr_in6 *sin6_src,
114 				    struct sockaddr_in6 *sin6_dest __unused ) {
115 	struct sockaddr_tcpip *st_src =
116 		( ( struct sockaddr_tcpip * ) sin6_src );
117 
118 	return icmp_rx_echo_request ( iobuf, st_src, &icmpv6_echo_protocol );
119 }
120 
121 /** ICMPv6 echo request handler */
122 struct icmpv6_handler icmpv6_echo_request_handler __icmpv6_handler = {
123 	.type = ICMPV6_ECHO_REQUEST,
124 	.rx = icmpv6_rx_echo_request,
125 };
126 
127 /**
128  * Process received ICMPv6 echo reply packet
129  *
130  * @v iobuf		I/O buffer
131  * @v netdev		Network device
132  * @v sin6_src		Source socket address
133  * @v sin6_dest		Destination socket address
134  * @ret rc		Return status code
135  */
icmpv6_rx_echo_reply(struct io_buffer * iobuf,struct net_device * netdev __unused,struct sockaddr_in6 * sin6_src,struct sockaddr_in6 * sin6_dest __unused)136 static int icmpv6_rx_echo_reply ( struct io_buffer *iobuf,
137 				  struct net_device *netdev __unused,
138 				  struct sockaddr_in6 *sin6_src,
139 				  struct sockaddr_in6 *sin6_dest __unused ) {
140 	struct sockaddr_tcpip *st_src =
141 		( ( struct sockaddr_tcpip * ) sin6_src );
142 
143 	return icmp_rx_echo_reply ( iobuf, st_src );
144 }
145 
146 /** ICMPv6 echo reply handler */
147 struct icmpv6_handler icmpv6_echo_reply_handler __icmpv6_handler = {
148 	.type = ICMPV6_ECHO_REPLY,
149 	.rx = icmpv6_rx_echo_reply,
150 };
151 
152 /**
153  * Identify ICMPv6 handler
154  *
155  * @v type		ICMPv6 type
156  * @ret handler		ICMPv6 handler, or NULL if not found
157  */
icmpv6_handler(unsigned int type)158 static struct icmpv6_handler * icmpv6_handler ( unsigned int type ) {
159 	struct icmpv6_handler *handler;
160 
161 	for_each_table_entry ( handler, ICMPV6_HANDLERS ) {
162 		if ( handler->type == type )
163 			return handler;
164 	}
165 	return NULL;
166 }
167 
168 /**
169  * Process a received packet
170  *
171  * @v iobuf		I/O buffer
172  * @v netdev		Network device
173  * @v st_src		Partially-filled source address
174  * @v st_dest		Partially-filled destination address
175  * @v pshdr_csum	Pseudo-header checksum
176  * @ret rc		Return status code
177  */
icmpv6_rx(struct io_buffer * iobuf,struct net_device * netdev,struct sockaddr_tcpip * st_src,struct sockaddr_tcpip * st_dest,uint16_t pshdr_csum)178 static int icmpv6_rx ( struct io_buffer *iobuf, struct net_device *netdev,
179 		       struct sockaddr_tcpip *st_src,
180 		       struct sockaddr_tcpip *st_dest, uint16_t pshdr_csum ) {
181 	struct sockaddr_in6 *sin6_src = ( ( struct sockaddr_in6 * ) st_src );
182 	struct sockaddr_in6 *sin6_dest = ( ( struct sockaddr_in6 * ) st_dest );
183 	struct icmp_header *icmp = iobuf->data;
184 	size_t len = iob_len ( iobuf );
185 	struct icmpv6_handler *handler;
186 	unsigned int csum;
187 	int rc;
188 
189 	/* Sanity check */
190 	if ( len < sizeof ( *icmp ) ) {
191 		DBGC ( netdev, "ICMPv6 packet too short at %zd bytes (min %zd "
192 		       "bytes)\n", len, sizeof ( *icmp ) );
193 		rc = -EINVAL;
194 		goto done;
195 	}
196 
197 	/* Verify checksum */
198 	csum = tcpip_continue_chksum ( pshdr_csum, icmp, len );
199 	if ( csum != 0 ) {
200 		DBGC ( netdev, "ICMPv6 checksum incorrect (is %04x, should be "
201 		       "0000)\n", csum );
202 		DBGC_HDA ( netdev, 0, icmp, len );
203 		rc = -EINVAL;
204 		goto done;
205 	}
206 
207 	/* Identify handler */
208 	handler = icmpv6_handler ( icmp->type );
209 	if ( ! handler ) {
210 		switch ( icmp->type ) {
211 		case ICMPV6_DESTINATION_UNREACHABLE:
212 			rc = -EHOSTUNREACH_CODE ( icmp->code );
213 			break;
214 		case ICMPV6_PACKET_TOO_BIG:
215 			rc = -ERANGE;
216 			break;
217 		case ICMPV6_TIME_EXCEEDED:
218 			rc = -ETIMEDOUT_CODE ( icmp->code );
219 			break;
220 		case ICMPV6_PARAMETER_PROBLEM:
221 			rc = -EPROTO_CODE ( icmp->code );
222 			break;
223 		default:
224 			DBGC ( netdev, "ICMPv6 unrecognised type %d code %d\n",
225 			       icmp->type, icmp->code );
226 			rc = -ENOTSUP;
227 			break;
228 		};
229 		goto done;
230 	}
231 
232 	/* Pass to handler */
233 	if ( ( rc = handler->rx ( iob_disown ( iobuf ), netdev, sin6_src,
234 				  sin6_dest ) ) != 0 ) {
235 		DBGC ( netdev, "ICMPv6 could not handle type %d: %s\n",
236 		       icmp->type, strerror ( rc ) );
237 		goto done;
238 	}
239 
240  done:
241 	free_iob ( iobuf );
242 	return rc;
243 }
244 
245 /** ICMPv6 TCP/IP protocol */
246 struct tcpip_protocol icmpv6_protocol __tcpip_protocol = {
247 	.name = "ICMPv6",
248 	.rx = icmpv6_rx,
249 	.tcpip_proto = IP_ICMP6,
250 };
251 
252 /** ICMPv6 echo protocol */
253 struct icmp_echo_protocol icmpv6_echo_protocol __icmp_echo_protocol = {
254 	.family = AF_INET6,
255 	.request = ICMPV6_ECHO_REQUEST,
256 	.reply = ICMPV6_ECHO_REPLY,
257 	.tcpip_protocol = &icmpv6_protocol,
258 	.net_checksum = 1,
259 };
260