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 <stdlib.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <byteswap.h>
30 #include <ipxe/refcnt.h>
31 #include <ipxe/list.h>
32 #include <ipxe/iobuf.h>
33 #include <ipxe/tcpip.h>
34 #include <ipxe/icmp.h>
35 #include <ipxe/interface.h>
36 #include <ipxe/xfer.h>
37 #include <ipxe/open.h>
38 #include <ipxe/netdevice.h>
39 #include <ipxe/ping.h>
40
41 /** @file
42 *
43 * ICMP ping protocol
44 *
45 */
46
47 /**
48 * A ping connection
49 *
50 */
51 struct ping_connection {
52 /** Reference counter */
53 struct refcnt refcnt;
54 /** List of ping connections */
55 struct list_head list;
56
57 /** Remote socket address */
58 struct sockaddr_tcpip peer;
59 /** Local port number */
60 uint16_t port;
61
62 /** Data transfer interface */
63 struct interface xfer;
64 };
65
66 /** List of registered ping connections */
67 static LIST_HEAD ( ping_conns );
68
69 /**
70 * Identify ping connection by local port number
71 *
72 * @v port Local port number
73 * @ret ping Ping connection, or NULL
74 */
ping_demux(unsigned int port)75 static struct ping_connection * ping_demux ( unsigned int port ) {
76 struct ping_connection *ping;
77
78 list_for_each_entry ( ping, &ping_conns, list ) {
79 if ( ping->port == port )
80 return ping;
81 }
82 return NULL;
83 }
84
85 /**
86 * Check if local port number is available
87 *
88 * @v port Local port number
89 * @ret port Local port number, or negative error
90 */
ping_port_available(int port)91 static int ping_port_available ( int port ) {
92
93 return ( ping_demux ( port ) ? -EADDRINUSE : port );
94 }
95
96 /**
97 * Process ICMP ping reply
98 *
99 * @v iobuf I/O buffer
100 * @v st_src Source address
101 * @ret rc Return status code
102 */
ping_rx(struct io_buffer * iobuf,struct sockaddr_tcpip * st_src)103 int ping_rx ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src ) {
104 struct icmp_echo *echo = iobuf->data;
105 struct ping_connection *ping;
106 struct xfer_metadata meta;
107 int rc;
108
109 /* Sanity check: should already have been checked by ICMP layer */
110 assert ( iob_len ( iobuf ) >= sizeof ( *echo ) );
111
112 /* Identify connection */
113 ping = ping_demux ( ntohs ( echo->ident ) );
114 DBGC ( ping, "PING %p reply id %#04x seq %#04x\n",
115 ping, ntohs ( echo->ident ), ntohs ( echo->sequence ) );
116 if ( ! ping ) {
117 rc = -ENOTCONN;
118 goto discard;
119 }
120
121 /* Strip header, construct metadata, and pass data to upper layer */
122 iob_pull ( iobuf, sizeof ( *echo ) );
123 memset ( &meta, 0, sizeof ( meta ) );
124 meta.src = ( ( struct sockaddr * ) st_src );
125 meta.flags = XFER_FL_ABS_OFFSET;
126 meta.offset = ntohs ( echo->sequence );
127 return xfer_deliver ( &ping->xfer, iob_disown ( iobuf ), &meta );
128
129 discard:
130 free_iob ( iobuf );
131 return rc;
132 }
133
134 /**
135 * Allocate I/O buffer for ping
136 *
137 * @v ping Ping connection
138 * @v len Payload size
139 * @ret iobuf I/O buffer, or NULL
140 */
141 static struct io_buffer *
ping_alloc_iob(struct ping_connection * ping __unused,size_t len)142 ping_alloc_iob ( struct ping_connection *ping __unused, size_t len ) {
143 size_t header_len;
144 struct io_buffer *iobuf;
145
146 header_len = ( MAX_LL_NET_HEADER_LEN + sizeof ( struct icmp_echo ) );
147 iobuf = alloc_iob ( header_len + len );
148 if ( iobuf )
149 iob_reserve ( iobuf, header_len );
150 return iobuf;
151 }
152
153 /**
154 * Deliver datagram as I/O buffer
155 *
156 * @v ping Ping connection
157 * @v iobuf I/O buffer
158 * @v meta Data transfer metadata
159 * @ret rc Return status code
160 */
ping_deliver(struct ping_connection * ping,struct io_buffer * iobuf,struct xfer_metadata * meta)161 static int ping_deliver ( struct ping_connection *ping, struct io_buffer *iobuf,
162 struct xfer_metadata *meta ) {
163 struct icmp_echo *echo = iob_push ( iobuf, sizeof ( *echo ) );
164 int rc;
165
166 /* Construct header */
167 memset ( echo, 0, sizeof ( *echo ) );
168 echo->ident = htons ( ping->port );
169 echo->sequence = htons ( meta->offset );
170
171 /* Transmit echo request */
172 if ( ( rc = icmp_tx_echo_request ( iob_disown ( iobuf ),
173 &ping->peer ) ) != 0 ) {
174 DBGC ( ping, "PING %p could not transmit: %s\n",
175 ping, strerror ( rc ) );
176 return rc;
177 }
178
179 return 0;
180 }
181
182 /**
183 * Close ping connection
184 *
185 * @v ping Ping connection
186 * @v rc Reason for close
187 */
ping_close(struct ping_connection * ping,int rc)188 static void ping_close ( struct ping_connection *ping, int rc ) {
189
190 /* Close data transfer interface */
191 intf_shutdown ( &ping->xfer, rc );
192
193 /* Remove from list of connections and drop list's reference */
194 list_del ( &ping->list );
195 ref_put ( &ping->refcnt );
196
197 DBGC ( ping, "PING %p closed\n", ping );
198 }
199
200 /** Ping data transfer interface operations */
201 static struct interface_operation ping_xfer_operations[] = {
202 INTF_OP ( xfer_deliver, struct ping_connection *, ping_deliver ),
203 INTF_OP ( xfer_alloc_iob, struct ping_connection *, ping_alloc_iob ),
204 INTF_OP ( intf_close, struct ping_connection *, ping_close ),
205 };
206
207 /** Ping data transfer interface descriptor */
208 static struct interface_descriptor ping_xfer_desc =
209 INTF_DESC ( struct ping_connection, xfer, ping_xfer_operations );
210
211 /**
212 * Open a ping connection
213 *
214 * @v xfer Data transfer interface
215 * @v peer Peer socket address
216 * @v local Local socket address, or NULL
217 * @ret rc Return status code
218 */
ping_open(struct interface * xfer,struct sockaddr * peer,struct sockaddr * local)219 static int ping_open ( struct interface *xfer, struct sockaddr *peer,
220 struct sockaddr *local ) {
221 struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
222 struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
223 struct ping_connection *ping;
224 int port;
225 int rc;
226
227 /* Allocate and initialise structure */
228 ping = zalloc ( sizeof ( *ping ) );
229 if ( ! ping ) {
230 rc = -ENOMEM;
231 goto err_alloc;
232 }
233 DBGC ( ping, "PING %p allocated\n", ping );
234 ref_init ( &ping->refcnt, NULL );
235 intf_init ( &ping->xfer, &ping_xfer_desc, &ping->refcnt );
236 memcpy ( &ping->peer, st_peer, sizeof ( ping->peer ) );
237
238 /* Bind to local port */
239 port = tcpip_bind ( st_local, ping_port_available );
240 if ( port < 0 ) {
241 rc = port;
242 DBGC ( ping, "PING %p could not bind: %s\n",
243 ping, strerror ( rc ) );
244 goto err_bind;
245 }
246 ping->port = port;
247 DBGC ( ping, "PING %p bound to id %#04x\n", ping, port );
248
249 /* Attach parent interface, transfer reference to connection
250 * list, and return
251 */
252 intf_plug_plug ( &ping->xfer, xfer );
253 list_add ( &ping->list, &ping_conns );
254 return 0;
255
256 err_bind:
257 ref_put ( &ping->refcnt );
258 err_alloc:
259 return rc;
260 }
261
262 /** Ping socket opener */
263 struct socket_opener ping_socket_opener __socket_opener = {
264 .semantics = PING_SOCK_ECHO,
265 .open = ping_open,
266 };
267
268 /** Linkage hack */
269 int ping_sock_echo = PING_SOCK_ECHO;
270