src/net/icmp.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 <string.h>
  27 #include <byteswap.h>
  28 #include <errno.h>
  29 #include <ipxe/iobuf.h>
  30 #include <ipxe/in.h>
  31 #include <ipxe/tcpip.h>
  32 #include <ipxe/ping.h>
  33 #include <ipxe/crc32.h>
  34 #include <ipxe/icmp.h>
  35
  36 /** @file
  37  *
  38  * ICMP protocol
  39  *
  40  */
  41
  42 /**
  43  * Identify ICMP echo protocol
  44  *
  45  * @v st_family         Address family
  46  * @ret echo_protocol   ICMP echo protocol, or NULL
  47  */
  48 static struct icmp_echo_protocol * icmp_echo_protocol ( sa_family_t family ) {
  49         struct icmp_echo_protocol *echo_protocol;
  50
  51         for_each_table_entry ( echo_protocol, ICMP_ECHO_PROTOCOLS ) {
  52                 if ( echo_protocol->family == family )
  53                         return echo_protocol;
  54         }
  55         return NULL;
  56 }
  57
  58 /**
  59  *
  60  * Determine debugging colour for ICMP debug messages
  61  *
  62  * @v st_peer           Peer address
  63  * @ret col             Debugging colour (for DBGC())
  64  */
  65 static uint32_t icmpcol ( struct sockaddr_tcpip *st_peer ) {
  66
  67         return crc32_le ( 0, st_peer, sizeof ( *st_peer ) );
  68 }
  69
  70 /**
  71  * Transmit ICMP echo packet
  72  *
  73  * @v iobuf             I/O buffer
  74  * @v st_dest           Destination socket address
  75  * @v echo_protocol     ICMP echo protocol
  76  * @ret rc              Return status code
  77  */
  78 static int icmp_tx_echo ( struct io_buffer *iobuf,
  79                           struct sockaddr_tcpip *st_dest,
  80                           struct icmp_echo_protocol *echo_protocol ) {
  81         struct icmp_echo *echo = iobuf->data;
  82         int rc;
  83
  84         /* Set ICMP type and (re)calculate checksum */
  85         echo->icmp.chksum = 0;
  86         echo->icmp.chksum = tcpip_chksum ( echo, iob_len ( iobuf ) );
  87
  88         /* Transmit packet */
  89         if ( ( rc = tcpip_tx ( iobuf, echo_protocol->tcpip_protocol, NULL,
  90                                st_dest, NULL,
  91                                ( echo_protocol->net_checksum ?
  92                                  &echo->icmp.chksum : NULL ) ) ) != 0 )
  93                 return rc;
  94
  95         return 0;
  96 }
  97
  98 /**
  99  * Transmit ICMP echo request
 100  *
 101  * @v iobuf             I/O buffer
 102  * @v st_dest           Destination socket address
 103  * @ret rc              Return status code
 104  */
 105 int icmp_tx_echo_request ( struct io_buffer *iobuf,
 106                            struct sockaddr_tcpip *st_dest ) {
 107         struct icmp_echo *echo = iobuf->data;
 108         struct icmp_echo_protocol *echo_protocol;
 109         int rc;
 110
 111         /* Identify ICMP echo protocol */
 112         echo_protocol = icmp_echo_protocol ( st_dest->st_family );
 113         if ( ! echo_protocol ) {
 114                 DBGC ( icmpcol ( st_dest ), "ICMP TX echo request unknown "
 115                        "address family %d\n", st_dest->st_family );
 116                 free_iob ( iobuf );
 117                 return -ENOTSUP;
 118         }
 119
 120         /* Set type */
 121         echo->icmp.type = echo_protocol->request;
 122
 123         /* Transmit request */
 124         DBGC ( icmpcol ( st_dest ), "ICMP TX echo request id %04x seq %04x\n",
 125                ntohs ( echo->ident ), ntohs ( echo->sequence ) );
 126         if ( ( rc = icmp_tx_echo ( iobuf, st_dest, echo_protocol ) ) != 0 )
 127                 return rc;
 128
 129         return 0;
 130 }
 131
 132 /**
 133  * Transmit ICMP echo reply
 134  *
 135  * @v iobuf             I/O buffer
 136  * @v st_dest           Destination socket address
 137  * @ret rc              Return status code
 138  */
 139 static int icmp_tx_echo_reply ( struct io_buffer *iobuf,
 140                                 struct sockaddr_tcpip *st_dest,
 141                                 struct icmp_echo_protocol *echo_protocol ) {
 142         struct icmp_echo *echo = iobuf->data;
 143         int rc;
 144
 145         /* Set type */
 146         echo->icmp.type = echo_protocol->reply;
 147
 148         /* Transmit reply */
 149         DBGC ( icmpcol ( st_dest ), "ICMP TX echo reply id %04x seq %04x\n",
 150                ntohs ( echo->ident ), ntohs ( echo->sequence ) );
 151         if ( ( rc = icmp_tx_echo ( iobuf, st_dest, echo_protocol ) ) != 0 )
 152                 return rc;
 153
 154         return 0;
 155 }
 156
 157 /**
 158  * Process a received ICMP echo request
 159  *
 160  * @v iobuf             I/O buffer
 161  * @v st_src            Source socket address
 162  * @v echo_protocol     ICMP echo protocol
 163  * @ret rc              Return status code
 164  */
 165 int icmp_rx_echo_request ( struct io_buffer *iobuf,
 166                            struct sockaddr_tcpip *st_src,
 167                            struct icmp_echo_protocol *echo_protocol ) {
 168         struct icmp_echo *echo = iobuf->data;
 169         int rc;
 170
 171         /* Sanity check */
 172         if ( iob_len ( iobuf ) < sizeof ( *echo ) ) {
 173                 DBGC ( icmpcol ( st_src ), "ICMP RX echo request too short at "
 174                        "%zd bytes (min %zd bytes)\n",
 175                        iob_len ( iobuf ), sizeof ( *echo ) );
 176                 free_iob ( iobuf );
 177                 return -EINVAL;
 178         }
 179         DBGC ( icmpcol ( st_src ), "ICMP RX echo request id %04x seq %04x\n",
 180                ntohs ( echo->ident ), ntohs ( echo->sequence ) );
 181
 182         /* Transmit echo reply */
 183         if ( ( rc = icmp_tx_echo_reply ( iobuf, st_src, echo_protocol ) ) != 0 )
 184                 return rc;
 185
 186         return 0;
 187 }
 188
 189 /**
 190  * Process a received ICMP echo request
 191  *
 192  * @v iobuf             I/O buffer
 193  * @v st_src            Source socket address
 194  * @ret rc              Return status code
 195  */
 196 int icmp_rx_echo_reply ( struct io_buffer *iobuf,
 197                          struct sockaddr_tcpip *st_src ) {
 198         struct icmp_echo *echo = iobuf->data;
 199         int rc;
 200
 201         /* Sanity check */
 202         if ( iob_len ( iobuf ) < sizeof ( *echo ) ) {
 203                 DBGC ( icmpcol ( st_src ), "ICMP RX echo reply too short at "
 204                        "%zd bytes (min %zd bytes)\n",
 205                        iob_len ( iobuf ), sizeof ( *echo ) );
 206                 free_iob ( iobuf );
 207                 return -EINVAL;
 208         }
 209         DBGC ( icmpcol ( st_src ), "ICMP RX echo reply id %04x seq %04x\n",
 210                ntohs ( echo->ident ), ntohs ( echo->sequence ) );
 211
 212         /* Deliver to ping protocol */
 213         if ( ( rc = ping_rx ( iobuf, st_src ) ) != 0 )
 214                 return rc;
 215
 216         return 0;
 217 }
 218
 219 /**
 220  * Receive ping reply (when no ping protocol is present)
 221  *
 222  * @v iobuf             I/O buffer
 223  * @v st_src            Source socket address
 224  * @ret rc              Return status code
 225  */
 226 __weak int ping_rx ( struct io_buffer *iobuf,
 227                      struct sockaddr_tcpip *st_src __unused ) {
 228         free_iob ( iobuf );
 229         return 0;
 230 }