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 <ipxe/refcnt.h>
30 #include <ipxe/interface.h>
31 #include <ipxe/job.h>
32 #include <ipxe/xfer.h>
33 #include <ipxe/iobuf.h>
34 #include <ipxe/open.h>
35 #include <ipxe/socket.h>
36 #include <ipxe/retry.h>
37 #include <ipxe/pinger.h>
38
39 /** @file
40 *
41 * ICMP ping sender
42 *
43 */
44
45 /* Disambiguate the various error causes */
46 #define EPROTO_LEN __einfo_error ( EINFO_EPROTO_LEN )
47 #define EINFO_EPROTO_LEN __einfo_uniqify ( EINFO_EPROTO, 0x01, \
48 "Incorrect reply length" )
49 #define EPROTO_DATA __einfo_error ( EINFO_EPROTO_DATA )
50 #define EINFO_EPROTO_DATA __einfo_uniqify ( EINFO_EPROTO, 0x02, \
51 "Incorrect reply data" )
52 #define EPROTO_SEQ __einfo_error ( EINFO_EPROTO_SEQ )
53 #define EINFO_EPROTO_SEQ __einfo_uniqify ( EINFO_EPROTO, 0x03, \
54 "Delayed or out-of-sequence reply" )
55
56 /** A pinger */
57 struct pinger {
58 /** Reference count */
59 struct refcnt refcnt;
60
61 /** Job control interface */
62 struct interface job;
63 /** Data transfer interface */
64 struct interface xfer;
65
66 /** Timer */
67 struct retry_timer timer;
68 /** Timeout */
69 unsigned long timeout;
70
71 /** Payload length */
72 size_t len;
73 /** Current sequence number */
74 uint16_t sequence;
75 /** Response for current sequence number is still pending */
76 int pending;
77 /** Number of remaining expiry events (zero to continue indefinitely) */
78 unsigned int remaining;
79 /** Return status */
80 int rc;
81
82 /** Callback function
83 *
84 * @v src Source socket address, or NULL
85 * @v sequence Sequence number
86 * @v len Payload length
87 * @v rc Status code
88 */
89 void ( * callback ) ( struct sockaddr *src, unsigned int sequence,
90 size_t len, int rc );
91 };
92
93 /**
94 * Generate payload
95 *
96 * @v pinger Pinger
97 * @v data Data buffer
98 */
pinger_generate(struct pinger * pinger,void * data)99 static void pinger_generate ( struct pinger *pinger, void *data ) {
100 uint8_t *bytes = data;
101 unsigned int i;
102
103 /* Generate byte sequence */
104 for ( i = 0 ; i < pinger->len ; i++ )
105 bytes[i] = ( i & 0xff );
106 }
107
108 /**
109 * Verify payload
110 *
111 * @v pinger Pinger
112 * @v data Data buffer
113 * @ret rc Return status code
114 */
pinger_verify(struct pinger * pinger,const void * data)115 static int pinger_verify ( struct pinger *pinger, const void *data ) {
116 const uint8_t *bytes = data;
117 unsigned int i;
118
119 /* Check byte sequence */
120 for ( i = 0 ; i < pinger->len ; i++ ) {
121 if ( bytes[i] != ( i & 0xff ) )
122 return -EPROTO_DATA;
123 }
124
125 return 0;
126 }
127
128 /**
129 * Close pinger
130 *
131 * @v pinger Pinger
132 * @v rc Reason for close
133 */
pinger_close(struct pinger * pinger,int rc)134 static void pinger_close ( struct pinger *pinger, int rc ) {
135
136 /* Stop timer */
137 stop_timer ( &pinger->timer );
138
139 /* Shut down interfaces */
140 intf_shutdown ( &pinger->xfer, rc );
141 intf_shutdown ( &pinger->job, rc );
142 }
143
144 /**
145 * Handle data transfer window change
146 *
147 * @v pinger Pinger
148 */
pinger_window_changed(struct pinger * pinger)149 static void pinger_window_changed ( struct pinger *pinger ) {
150
151 /* Do nothing if timer is already running */
152 if ( timer_running ( &pinger->timer ) )
153 return;
154
155 /* Start timer when window opens for the first time */
156 if ( xfer_window ( &pinger->xfer ) )
157 start_timer_nodelay ( &pinger->timer );
158 }
159
160 /**
161 * Handle timer expiry
162 *
163 * @v timer Timer
164 * @v over Failure indicator
165 */
pinger_expired(struct retry_timer * timer,int over __unused)166 static void pinger_expired ( struct retry_timer *timer, int over __unused ) {
167 struct pinger *pinger = container_of ( timer, struct pinger, timer );
168 struct xfer_metadata meta;
169 struct io_buffer *iobuf;
170 int rc;
171
172 /* If no response has been received, notify the callback function */
173 if ( pinger->pending && pinger->callback )
174 pinger->callback ( NULL, pinger->sequence, 0, -ETIMEDOUT );
175
176 /* Check for termination */
177 if ( pinger->remaining && ( --pinger->remaining == 0 ) ) {
178 pinger_close ( pinger, pinger->rc );
179 return;
180 }
181
182 /* Increase sequence number */
183 pinger->sequence++;
184
185 /* Restart timer. Do this before attempting to transmit, in
186 * case the transmission attempt fails.
187 */
188 start_timer_fixed ( &pinger->timer, pinger->timeout );
189 pinger->pending = 1;
190
191 /* Allocate I/O buffer */
192 iobuf = xfer_alloc_iob ( &pinger->xfer, pinger->len );
193 if ( ! iobuf ) {
194 DBGC ( pinger, "PINGER %p could not allocate I/O buffer\n",
195 pinger );
196 return;
197 }
198
199 /* Generate payload */
200 pinger_generate ( pinger, iob_put ( iobuf, pinger->len ) );
201
202 /* Generate metadata */
203 memset ( &meta, 0, sizeof ( meta ) );
204 meta.flags = XFER_FL_ABS_OFFSET;
205 meta.offset = pinger->sequence;
206
207 /* Transmit packet */
208 if ( ( rc = xfer_deliver ( &pinger->xfer, iobuf, &meta ) ) != 0 ) {
209 DBGC ( pinger, "PINGER %p could not transmit: %s\n",
210 pinger, strerror ( rc ) );
211 return;
212 }
213 }
214
215 /**
216 * Handle received data
217 *
218 * @v pinger Pinger
219 * @v iobuf I/O buffer
220 * @v meta Data transfer metadata
221 * @ret rc Return status code
222 */
pinger_deliver(struct pinger * pinger,struct io_buffer * iobuf,struct xfer_metadata * meta)223 static int pinger_deliver ( struct pinger *pinger, struct io_buffer *iobuf,
224 struct xfer_metadata *meta ) {
225 size_t len = iob_len ( iobuf );
226 uint16_t sequence = meta->offset;
227 int terminate = 0;
228 int rc;
229
230 /* Clear response pending flag, if applicable */
231 if ( sequence == pinger->sequence )
232 pinger->pending = 0;
233
234 /* Check for errors */
235 if ( len != pinger->len ) {
236 /* Incorrect length: terminate immediately if we are
237 * not pinging indefinitely.
238 */
239 DBGC ( pinger, "PINGER %p received incorrect length %zd "
240 "(expected %zd)\n", pinger, len, pinger->len );
241 rc = -EPROTO_LEN;
242 terminate = ( pinger->remaining != 0 );
243 } else if ( ( rc = pinger_verify ( pinger, iobuf->data ) ) != 0 ) {
244 /* Incorrect data: terminate immediately if we are not
245 * pinging indefinitely.
246 */
247 DBGC ( pinger, "PINGER %p received incorrect data:\n", pinger );
248 DBGC_HDA ( pinger, 0, iobuf->data, iob_len ( iobuf ) );
249 terminate = ( pinger->remaining != 0 );
250 } else if ( sequence != pinger->sequence ) {
251 /* Incorrect sequence number (probably a delayed response):
252 * report via callback but otherwise ignore.
253 */
254 DBGC ( pinger, "PINGER %p received sequence %d (expected %d)\n",
255 pinger, sequence, pinger->sequence );
256 rc = -EPROTO_SEQ;
257 terminate = 0;
258 } else {
259 /* Success: record that a packet was successfully received,
260 * and terminate if we expect to send no further packets.
261 */
262 rc = 0;
263 pinger->rc = 0;
264 terminate = ( pinger->remaining == 1 );
265 }
266
267 /* Discard I/O buffer */
268 free_iob ( iobuf );
269
270 /* Notify callback function, if applicable */
271 if ( pinger->callback )
272 pinger->callback ( meta->src, sequence, len, rc );
273
274 /* Terminate if applicable */
275 if ( terminate )
276 pinger_close ( pinger, rc );
277
278 return rc;
279 }
280
281 /** Pinger data transfer interface operations */
282 static struct interface_operation pinger_xfer_op[] = {
283 INTF_OP ( xfer_deliver, struct pinger *, pinger_deliver ),
284 INTF_OP ( xfer_window_changed, struct pinger *, pinger_window_changed ),
285 INTF_OP ( intf_close, struct pinger *, pinger_close ),
286 };
287
288 /** Pinger data transfer interface descriptor */
289 static struct interface_descriptor pinger_xfer_desc =
290 INTF_DESC ( struct pinger, xfer, pinger_xfer_op );
291
292 /** Pinger job control interface operations */
293 static struct interface_operation pinger_job_op[] = {
294 INTF_OP ( intf_close, struct pinger *, pinger_close ),
295 };
296
297 /** Pinger job control interface descriptor */
298 static struct interface_descriptor pinger_job_desc =
299 INTF_DESC ( struct pinger, job, pinger_job_op );
300
301 /**
302 * Create pinger
303 *
304 * @v job Job control interface
305 * @v hostname Hostname to ping
306 * @v timeout Timeout (in ticks)
307 * @v len Payload length
308 * @v count Number of packets to send (or zero for no limit)
309 * @v callback Callback function (or NULL)
310 * @ret rc Return status code
311 */
create_pinger(struct interface * job,const char * hostname,unsigned long timeout,size_t len,unsigned int count,void (* callback)(struct sockaddr * src,unsigned int sequence,size_t len,int rc))312 int create_pinger ( struct interface *job, const char *hostname,
313 unsigned long timeout, size_t len, unsigned int count,
314 void ( * callback ) ( struct sockaddr *src,
315 unsigned int sequence, size_t len,
316 int rc ) ) {
317 struct pinger *pinger;
318 int rc;
319
320 /* Sanity check */
321 if ( ! timeout )
322 return -EINVAL;
323
324 /* Allocate and initialise structure */
325 pinger = zalloc ( sizeof ( *pinger ) );
326 if ( ! pinger )
327 return -ENOMEM;
328 ref_init ( &pinger->refcnt, NULL );
329 intf_init ( &pinger->job, &pinger_job_desc, &pinger->refcnt );
330 intf_init ( &pinger->xfer, &pinger_xfer_desc, &pinger->refcnt );
331 timer_init ( &pinger->timer, pinger_expired, &pinger->refcnt );
332 pinger->timeout = timeout;
333 pinger->len = len;
334 pinger->remaining = ( count ? ( count + 1 /* Initial packet */ ) : 0 );
335 pinger->callback = callback;
336 pinger->rc = -ETIMEDOUT;
337
338 /* Open socket */
339 if ( ( rc = xfer_open_named_socket ( &pinger->xfer, SOCK_ECHO, NULL,
340 hostname, NULL ) ) != 0 ) {
341 DBGC ( pinger, "PINGER %p could not open socket: %s\n",
342 pinger, strerror ( rc ) );
343 goto err;
344 }
345
346 /* Attach parent interface, mortalise self, and return */
347 intf_plug_plug ( &pinger->job, job );
348 ref_put ( &pinger->refcnt );
349 return 0;
350
351 err:
352 pinger_close ( pinger, rc );
353 ref_put ( &pinger->refcnt );
354 return rc;
355 }
356