1 /*
2 * Copyright (C) 2008 Stefan Hajnoczi <stefanha@gmail.com>.
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 #include <stdio.h>
20 #include <string.h>
21 #include <byteswap.h>
22 #include <gpxe/iobuf.h>
23 #include <gpxe/in.h>
24 #include <gpxe/if_arp.h>
25 #include <gpxe/if_ether.h>
26 #include <gpxe/ip.h>
27 #include <gpxe/udp.h>
28 #include <gpxe/netdevice.h>
29 #include <gpxe/nap.h>
30 #include <gpxe/gdbstub.h>
31 #include <gpxe/gdbudp.h>
32
33 /** @file
34 *
35 * GDB over UDP transport
36 *
37 */
38
39 enum {
40 DEFAULT_PORT = 43770, /* UDP listen port */
41 };
42
43 struct gdb_transport udp_gdb_transport __gdb_transport;
44
45 static struct net_device *netdev;
46 static uint8_t dest_eth[ETH_ALEN];
47 static struct sockaddr_in dest_addr;
48 static struct sockaddr_in source_addr;
49
gdbudp_ensure_netdev_open(struct net_device * netdev)50 static void gdbudp_ensure_netdev_open ( struct net_device *netdev ) {
51 /* The device may have been closed between breakpoints */
52 assert ( netdev );
53 netdev_open ( netdev );
54
55 /* Strictly speaking, we may need to close the device when leaving the interrupt handler */
56 }
57
gdbudp_recv(char * buf,size_t len)58 static size_t gdbudp_recv ( char *buf, size_t len ) {
59 struct io_buffer *iob;
60 struct ethhdr *ethhdr;
61 struct arphdr *arphdr;
62 struct iphdr *iphdr;
63 struct udp_header *udphdr;
64 size_t payload_len;
65
66 gdbudp_ensure_netdev_open ( netdev );
67
68 for ( ; ; ) {
69 netdev_poll ( netdev );
70 while ( ( iob = netdev_rx_dequeue ( netdev ) ) != NULL ) {
71 /* Ethernet header */
72 if ( iob_len ( iob ) < sizeof ( *ethhdr ) ) {
73 goto bad_packet;
74 }
75 ethhdr = iob->data;
76 iob_pull ( iob, sizeof ( *ethhdr ) );
77
78 /* Handle ARP requests so the client can find our MAC */
79 if ( ethhdr->h_protocol == htons ( ETH_P_ARP ) ) {
80 arphdr = iob->data;
81 if ( iob_len ( iob ) < sizeof ( *arphdr ) + 2 * ( ETH_ALEN + sizeof ( struct in_addr ) ) ||
82 arphdr->ar_hrd != htons ( ARPHRD_ETHER ) ||
83 arphdr->ar_pro != htons ( ETH_P_IP ) ||
84 arphdr->ar_hln != ETH_ALEN ||
85 arphdr->ar_pln != sizeof ( struct in_addr ) ||
86 arphdr->ar_op != htons ( ARPOP_REQUEST ) ||
87 * ( uint32_t * ) arp_target_pa ( arphdr ) != source_addr.sin_addr.s_addr ) {
88 goto bad_packet;
89 }
90
91 /* Generate an ARP reply */
92 arphdr->ar_op = htons ( ARPOP_REPLY );
93 memswap ( arp_sender_pa ( arphdr ), arp_target_pa ( arphdr ), sizeof ( struct in_addr ) );
94 memcpy ( arp_target_ha ( arphdr ), arp_sender_ha ( arphdr ), ETH_ALEN );
95 memcpy ( arp_sender_ha ( arphdr ), netdev->ll_addr, ETH_ALEN );
96
97 /* Fix up ethernet header */
98 ethhdr = iob_push ( iob, sizeof ( *ethhdr ) );
99 memcpy ( ethhdr->h_dest, ethhdr->h_source, ETH_ALEN );
100 memcpy ( ethhdr->h_source, netdev->ll_addr, ETH_ALEN );
101
102 netdev_tx ( netdev, iob );
103 continue; /* no need to free iob */
104 }
105
106 if ( ethhdr->h_protocol != htons ( ETH_P_IP ) ) {
107 goto bad_packet;
108 }
109
110 /* IP header */
111 if ( iob_len ( iob ) < sizeof ( *iphdr ) ) {
112 goto bad_packet;
113 }
114 iphdr = iob->data;
115 iob_pull ( iob, sizeof ( *iphdr ) );
116 if ( iphdr->protocol != IP_UDP || iphdr->dest.s_addr != source_addr.sin_addr.s_addr ) {
117 goto bad_packet;
118 }
119
120 /* UDP header */
121 if ( iob_len ( iob ) < sizeof ( *udphdr ) ) {
122 goto bad_packet;
123 }
124 udphdr = iob->data;
125 if ( udphdr->dest != source_addr.sin_port ) {
126 goto bad_packet;
127 }
128
129 /* Learn the remote connection details */
130 memcpy ( dest_eth, ethhdr->h_source, ETH_ALEN );
131 dest_addr.sin_addr.s_addr = iphdr->src.s_addr;
132 dest_addr.sin_port = udphdr->src;
133
134 /* Payload */
135 payload_len = ntohs ( udphdr->len );
136 if ( payload_len < sizeof ( *udphdr ) || payload_len > iob_len ( iob ) ) {
137 goto bad_packet;
138 }
139 payload_len -= sizeof ( *udphdr );
140 iob_pull ( iob, sizeof ( *udphdr ) );
141 if ( payload_len > len ) {
142 goto bad_packet;
143 }
144 memcpy ( buf, iob->data, payload_len );
145
146 free_iob ( iob );
147 return payload_len;
148
149 bad_packet:
150 free_iob ( iob );
151 }
152 cpu_nap();
153 }
154 }
155
gdbudp_send(const char * buf,size_t len)156 static void gdbudp_send ( const char *buf, size_t len ) {
157 struct io_buffer *iob;
158 struct ethhdr *ethhdr;
159 struct iphdr *iphdr;
160 struct udp_header *udphdr;
161
162 /* Check that we are connected */
163 if ( dest_addr.sin_port == 0 ) {
164 return;
165 }
166
167 gdbudp_ensure_netdev_open ( netdev );
168
169 iob = alloc_iob ( sizeof ( *ethhdr ) + sizeof ( *iphdr ) + sizeof ( *udphdr ) + len );
170 if ( !iob ) {
171 return;
172 }
173
174 /* Payload */
175 iob_reserve ( iob, sizeof ( *ethhdr ) + sizeof ( *iphdr ) + sizeof ( *udphdr ) );
176 memcpy ( iob_put ( iob, len ), buf, len );
177
178 /* UDP header */
179 udphdr = iob_push ( iob, sizeof ( *udphdr ) );
180 udphdr->src = source_addr.sin_port;
181 udphdr->dest = dest_addr.sin_port;
182 udphdr->len = htons ( iob_len ( iob ) );
183 udphdr->chksum = 0; /* optional and we are not using it */
184
185 /* IP header */
186 iphdr = iob_push ( iob, sizeof ( *iphdr ) );
187 memset ( iphdr, 0, sizeof ( *iphdr ) );
188 iphdr->verhdrlen = ( IP_VER | ( sizeof ( *iphdr ) / 4 ) );
189 iphdr->service = IP_TOS;
190 iphdr->len = htons ( iob_len ( iob ) );
191 iphdr->ttl = IP_TTL;
192 iphdr->protocol = IP_UDP;
193 iphdr->dest.s_addr = dest_addr.sin_addr.s_addr;
194 iphdr->src.s_addr = source_addr.sin_addr.s_addr;
195 iphdr->chksum = tcpip_chksum ( iphdr, sizeof ( *iphdr ) );
196
197 /* Ethernet header */
198 ethhdr = iob_push ( iob, sizeof ( *ethhdr ) );
199 memcpy ( ethhdr->h_dest, dest_eth, ETH_ALEN );
200 memcpy ( ethhdr->h_source, netdev->ll_addr, ETH_ALEN );
201 ethhdr->h_protocol = htons ( ETH_P_IP );
202
203 netdev_tx ( netdev, iob );
204 }
205
gdbudp_configure(const char * name,struct sockaddr_in * addr)206 struct gdb_transport *gdbudp_configure ( const char *name, struct sockaddr_in *addr ) {
207 struct settings *settings;
208
209 /* Release old network device */
210 netdev_put ( netdev );
211
212 netdev = find_netdev ( name );
213 if ( !netdev ) {
214 return NULL;
215 }
216
217 /* Hold network device */
218 netdev_get ( netdev );
219
220 /* Source UDP port */
221 source_addr.sin_port = ( addr && addr->sin_port ) ? addr->sin_port : htons ( DEFAULT_PORT );
222
223 /* Source IP address */
224 if ( addr && addr->sin_addr.s_addr ) {
225 source_addr.sin_addr.s_addr = addr->sin_addr.s_addr;
226 } else {
227 settings = netdev_settings ( netdev );
228 fetch_ipv4_setting ( settings, &ip_setting, &source_addr.sin_addr );
229 if ( source_addr.sin_addr.s_addr == 0 ) {
230 netdev_put ( netdev );
231 netdev = NULL;
232 return NULL;
233 }
234 }
235
236 return &udp_gdb_transport;
237 }
238
gdbudp_init(int argc,char ** argv)239 static int gdbudp_init ( int argc, char **argv ) {
240 if ( argc != 1 ) {
241 printf ( "udp: missing <interface> argument\n" );
242 return 1;
243 }
244
245 if ( !gdbudp_configure ( argv[0], NULL ) ) {
246 printf ( "%s: device does not exist or has no IP address\n", argv[0] );
247 return 1;
248 }
249 return 0;
250 }
251
252 struct gdb_transport udp_gdb_transport __gdb_transport = {
253 .name = "udp",
254 .init = gdbudp_init,
255 .send = gdbudp_send,
256 .recv = gdbudp_recv,
257 };
258