src/core/pinger.c

   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  */
  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  */
 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  */
 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  */
 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  */
 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  */
 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  */
 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 }