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Annotation of qemu/roms/ipxe/src/net/icmp.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (C) 2009 Michael Brown <[email protected]>.
                      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., 675 Mass Ave, Cambridge, MA 02139, USA.
                     17:  */
                     18: 
                     19: FILE_LICENCE ( GPL2_OR_LATER );
                     20: 
                     21: #include <string.h>
                     22: #include <errno.h>
                     23: #include <ipxe/iobuf.h>
                     24: #include <ipxe/in.h>
                     25: #include <ipxe/tcpip.h>
                     26: #include <ipxe/icmp.h>
                     27: 
                     28: /** @file
                     29:  *
                     30:  * ICMP protocol
                     31:  *
                     32:  */
                     33: 
                     34: struct tcpip_protocol icmp_protocol __tcpip_protocol;
                     35: 
                     36: /**
                     37:  * Process a received packet
                     38:  *
                     39:  * @v iobuf            I/O buffer
                     40:  * @v st_src           Partially-filled source address
                     41:  * @v st_dest          Partially-filled destination address
                     42:  * @v pshdr_csum       Pseudo-header checksum
                     43:  * @ret rc             Return status code
                     44:  */
                     45: static int icmp_rx ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src,
                     46:                     struct sockaddr_tcpip *st_dest,
                     47:                     uint16_t pshdr_csum __unused ) {
                     48:        struct icmp_header *icmp = iobuf->data;
                     49:        size_t len = iob_len ( iobuf );
                     50:        unsigned int csum;
                     51:        int rc;
                     52: 
                     53:        /* Sanity check */
                     54:        if ( len < sizeof ( *icmp ) ) {
                     55:                DBG ( "ICMP packet too short at %zd bytes (min %zd bytes)\n",
                     56:                      len, sizeof ( *icmp ) );
                     57:                rc = -EINVAL;
                     58:                goto done;
                     59:        }
                     60: 
                     61:        /* Verify checksum */
                     62:        csum = tcpip_chksum ( icmp, len );
                     63:        if ( csum != 0 ) {
                     64:                DBG ( "ICMP checksum incorrect (is %04x, should be 0000)\n",
                     65:                      csum );
                     66:                DBG_HD ( icmp, len );
                     67:                rc = -EINVAL;
                     68:                goto done;
                     69:        }
                     70: 
                     71:        /* We respond only to pings */
                     72:        if ( icmp->type != ICMP_ECHO_REQUEST ) {
                     73:                DBG ( "ICMP ignoring type %d\n", icmp->type );
                     74:                rc = 0;
                     75:                goto done;
                     76:        }
                     77: 
                     78:        DBG ( "ICMP responding to ping\n" );
                     79: 
                     80:        /* Change type to response and recalculate checksum */
                     81:        icmp->type = ICMP_ECHO_RESPONSE;
                     82:        icmp->chksum = 0;
                     83:        icmp->chksum = tcpip_chksum ( icmp, len );
                     84: 
                     85:        /* Transmit the response */
                     86:        if ( ( rc = tcpip_tx ( iob_disown ( iobuf ), &icmp_protocol, st_dest,
                     87:                               st_src, NULL, NULL ) ) != 0 ) {
                     88:                DBG ( "ICMP could not transmit ping response: %s\n",
                     89:                      strerror ( rc ) );
                     90:                goto done;
                     91:        }
                     92: 
                     93:  done:
                     94:        free_iob ( iobuf );
                     95:        return rc;
                     96: }
                     97: 
                     98: /** ICMP TCP/IP protocol */
                     99: struct tcpip_protocol icmp_protocol __tcpip_protocol = {
                    100:        .name = "ICMP",
                    101:        .rx = icmp_rx,
                    102:        .tcpip_proto = IP_ICMP,
                    103: };

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