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