[zbin] Fix check for existence of most recent output byte
[ipxe.git] / src / net / icmpv4.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
20 FILE_LICENCE ( GPL2_OR_LATER );
21
22 #include <string.h>
23 #include <errno.h>
24 #include <ipxe/iobuf.h>
25 #include <ipxe/in.h>
26 #include <ipxe/tcpip.h>
27 #include <ipxe/icmp.h>
28
29 /** @file
30 *
31 * ICMPv4 protocol
32 *
33 */
34
35 struct icmp_echo_protocol icmpv4_echo_protocol __icmp_echo_protocol;
36
37 /**
38 * Process a received packet
39 *
40 * @v iobuf I/O buffer
41 * @v netdev Network device
42 * @v st_src Partially-filled source address
43 * @v st_dest Partially-filled destination address
44 * @v pshdr_csum Pseudo-header checksum
45 * @ret rc Return status code
46 */
47 static int icmpv4_rx ( struct io_buffer *iobuf,
48 struct net_device *netdev __unused,
49 struct sockaddr_tcpip *st_src,
50 struct sockaddr_tcpip *st_dest __unused,
51 uint16_t pshdr_csum __unused ) {
52 struct icmp_header *icmp = iobuf->data;
53 size_t len = iob_len ( iobuf );
54 unsigned int csum;
55 unsigned int type;
56 int rc;
57
58 /* Sanity check */
59 if ( len < sizeof ( *icmp ) ) {
60 DBG ( "ICMP packet too short at %zd bytes (min %zd bytes)\n",
61 len, sizeof ( *icmp ) );
62 rc = -EINVAL;
63 goto discard;
64 }
65
66 /* Verify checksum */
67 csum = tcpip_chksum ( icmp, len );
68 if ( csum != 0 ) {
69 DBG ( "ICMP checksum incorrect (is %04x, should be 0000)\n",
70 csum );
71 DBG_HD ( icmp, len );
72 rc = -EINVAL;
73 goto discard;
74 }
75
76 /* Handle ICMP packet */
77 type = icmp->type;
78 switch ( type ) {
79 case ICMP_ECHO_REQUEST:
80 return icmp_rx_echo_request ( iobuf, st_src,
81 &icmpv4_echo_protocol );
82 case ICMP_ECHO_REPLY:
83 return icmp_rx_echo_reply ( iobuf, st_src );
84 default:
85 DBG ( "ICMP ignoring type %d\n", type );
86 rc = 0;
87 break;
88 }
89
90 discard:
91 free_iob ( iobuf );
92 return rc;
93 }
94
95 /** ICMPv4 TCP/IP protocol */
96 struct tcpip_protocol icmpv4_protocol __tcpip_protocol = {
97 .name = "ICMPv4",
98 .rx = icmpv4_rx,
99 .tcpip_proto = IP_ICMP,
100 };
101
102 /** ICMPv4 echo protocol */
103 struct icmp_echo_protocol icmpv4_echo_protocol __icmp_echo_protocol = {
104 .family = AF_INET,
105 .request = ICMP_ECHO_REQUEST,
106 .reply = ICMP_ECHO_REPLY,
107 .tcpip_protocol = &icmpv4_protocol,
108 .net_checksum = 0,
109 };