xref: /openbmc/u-boot/drivers/net/sandbox.c (revision e95bb1611043ff1ad5b63602e32bba302e402491)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2015 National Instruments
4  *
5  * (C) Copyright 2015
6  * Joe Hershberger <joe.hershberger@ni.com>
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <malloc.h>
12 #include <net.h>
13 #include <asm/test.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 /**
18  * struct eth_sandbox_priv - memory for sandbox mock driver
19  *
20  * fake_host_hwaddr: MAC address of mocked machine
21  * fake_host_ipaddr: IP address of mocked machine
22  * disabled: Will not respond
23  * recv_packet_buffer: buffer of the packet returned as received
24  * recv_packet_length: length of the packet returned as received
25  */
26 struct eth_sandbox_priv {
27 	uchar fake_host_hwaddr[ARP_HLEN];
28 	struct in_addr fake_host_ipaddr;
29 	bool disabled;
30 	uchar *recv_packet_buffer;
31 	int recv_packet_length;
32 };
33 
34 static bool skip_timeout;
35 
36 /*
37  * sandbox_eth_disable_response()
38  *
39  * index - The alias index (also DM seq number)
40  * disable - If non-zero, ignore sent packets and don't send mock response
41  */
42 void sandbox_eth_disable_response(int index, bool disable)
43 {
44 	struct udevice *dev;
45 	struct eth_sandbox_priv *priv;
46 	int ret;
47 
48 	ret = uclass_get_device(UCLASS_ETH, index, &dev);
49 	if (ret)
50 		return;
51 
52 	priv = dev_get_priv(dev);
53 	priv->disabled = disable;
54 }
55 
56 /*
57  * sandbox_eth_skip_timeout()
58  *
59  * When the first packet read is attempted, fast-forward time
60  */
61 void sandbox_eth_skip_timeout(void)
62 {
63 	skip_timeout = true;
64 }
65 
66 /*
67  * sandbox_eth_arp_req_to_reply()
68  *
69  * Check for an arp request to be sent. If so, inject a reply
70  *
71  * returns 0 if injected, -EAGAIN if not
72  */
73 int sandbox_eth_arp_req_to_reply(struct udevice *dev, void *packet,
74 				 unsigned int len)
75 {
76 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
77 	struct ethernet_hdr *eth = packet;
78 	struct arp_hdr *arp;
79 	struct ethernet_hdr *eth_recv;
80 	struct arp_hdr *arp_recv;
81 
82 	if (ntohs(eth->et_protlen) != PROT_ARP)
83 		return -EAGAIN;
84 
85 	arp = packet + ETHER_HDR_SIZE;
86 
87 	if (ntohs(arp->ar_op) != ARPOP_REQUEST)
88 		return -EAGAIN;
89 
90 	/* store this as the assumed IP of the fake host */
91 	priv->fake_host_ipaddr = net_read_ip(&arp->ar_tpa);
92 
93 	/* Formulate a fake response */
94 	eth_recv = (void *)priv->recv_packet_buffer;
95 	memcpy(eth_recv->et_dest, eth->et_src, ARP_HLEN);
96 	memcpy(eth_recv->et_src, priv->fake_host_hwaddr, ARP_HLEN);
97 	eth_recv->et_protlen = htons(PROT_ARP);
98 
99 	arp_recv = (void *)eth_recv + ETHER_HDR_SIZE;
100 	arp_recv->ar_hrd = htons(ARP_ETHER);
101 	arp_recv->ar_pro = htons(PROT_IP);
102 	arp_recv->ar_hln = ARP_HLEN;
103 	arp_recv->ar_pln = ARP_PLEN;
104 	arp_recv->ar_op = htons(ARPOP_REPLY);
105 	memcpy(&arp_recv->ar_sha, priv->fake_host_hwaddr, ARP_HLEN);
106 	net_write_ip(&arp_recv->ar_spa, priv->fake_host_ipaddr);
107 	memcpy(&arp_recv->ar_tha, &arp->ar_sha, ARP_HLEN);
108 	net_copy_ip(&arp_recv->ar_tpa, &arp->ar_spa);
109 
110 	priv->recv_packet_length = ETHER_HDR_SIZE + ARP_HDR_SIZE;
111 
112 	return 0;
113 }
114 
115 /*
116  * sandbox_eth_ping_req_to_reply()
117  *
118  * Check for a ping request to be sent. If so, inject a reply
119  *
120  * returns 0 if injected, -EAGAIN if not
121  */
122 int sandbox_eth_ping_req_to_reply(struct udevice *dev, void *packet,
123 				  unsigned int len)
124 {
125 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
126 	struct ethernet_hdr *eth = packet;
127 	struct ip_udp_hdr *ip;
128 	struct icmp_hdr *icmp;
129 	struct ethernet_hdr *eth_recv;
130 	struct ip_udp_hdr *ipr;
131 	struct icmp_hdr *icmpr;
132 
133 	if (ntohs(eth->et_protlen) != PROT_IP)
134 		return -EAGAIN;
135 
136 	ip = packet + ETHER_HDR_SIZE;
137 
138 	if (ip->ip_p != IPPROTO_ICMP)
139 		return -EAGAIN;
140 
141 	icmp = (struct icmp_hdr *)&ip->udp_src;
142 
143 	if (icmp->type != ICMP_ECHO_REQUEST)
144 		return -EAGAIN;
145 
146 	/* reply to the ping */
147 	eth_recv = (void *)priv->recv_packet_buffer;
148 	memcpy(eth_recv, packet, len);
149 	ipr = (void *)eth_recv + ETHER_HDR_SIZE;
150 	icmpr = (struct icmp_hdr *)&ipr->udp_src;
151 	memcpy(eth_recv->et_dest, eth->et_src, ARP_HLEN);
152 	memcpy(eth_recv->et_src, priv->fake_host_hwaddr, ARP_HLEN);
153 	ipr->ip_sum = 0;
154 	ipr->ip_off = 0;
155 	net_copy_ip((void *)&ipr->ip_dst, &ip->ip_src);
156 	net_write_ip((void *)&ipr->ip_src, priv->fake_host_ipaddr);
157 	ipr->ip_sum = compute_ip_checksum(ipr, IP_HDR_SIZE);
158 
159 	icmpr->type = ICMP_ECHO_REPLY;
160 	icmpr->checksum = 0;
161 	icmpr->checksum = compute_ip_checksum(icmpr, ICMP_HDR_SIZE);
162 
163 	priv->recv_packet_length = len;
164 
165 	return 0;
166 }
167 
168 static int sb_eth_start(struct udevice *dev)
169 {
170 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
171 
172 	debug("eth_sandbox: Start\n");
173 
174 	priv->recv_packet_buffer = net_rx_packets[0];
175 
176 	return 0;
177 }
178 
179 static int sb_eth_send(struct udevice *dev, void *packet, int length)
180 {
181 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
182 
183 	debug("eth_sandbox: Send packet %d\n", length);
184 
185 	if (priv->disabled)
186 		return 0;
187 
188 	if (!sandbox_eth_arp_req_to_reply(dev, packet, length))
189 		return 0;
190 	if (!sandbox_eth_ping_req_to_reply(dev, packet, length))
191 		return 0;
192 }
193 
194 static int sb_eth_recv(struct udevice *dev, int flags, uchar **packetp)
195 {
196 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
197 
198 	if (skip_timeout) {
199 		sandbox_timer_add_offset(11000UL);
200 		skip_timeout = false;
201 	}
202 
203 	if (priv->recv_packet_length) {
204 		int lcl_recv_packet_length = priv->recv_packet_length;
205 
206 		debug("eth_sandbox: received packet %d\n",
207 		      priv->recv_packet_length);
208 		priv->recv_packet_length = 0;
209 		*packetp = priv->recv_packet_buffer;
210 		return lcl_recv_packet_length;
211 	}
212 	return 0;
213 }
214 
215 static void sb_eth_stop(struct udevice *dev)
216 {
217 	debug("eth_sandbox: Stop\n");
218 }
219 
220 static int sb_eth_write_hwaddr(struct udevice *dev)
221 {
222 	struct eth_pdata *pdata = dev_get_platdata(dev);
223 
224 	debug("eth_sandbox %s: Write HW ADDR - %pM\n", dev->name,
225 	      pdata->enetaddr);
226 	return 0;
227 }
228 
229 static const struct eth_ops sb_eth_ops = {
230 	.start			= sb_eth_start,
231 	.send			= sb_eth_send,
232 	.recv			= sb_eth_recv,
233 	.stop			= sb_eth_stop,
234 	.write_hwaddr		= sb_eth_write_hwaddr,
235 };
236 
237 static int sb_eth_remove(struct udevice *dev)
238 {
239 	return 0;
240 }
241 
242 static int sb_eth_ofdata_to_platdata(struct udevice *dev)
243 {
244 	struct eth_pdata *pdata = dev_get_platdata(dev);
245 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
246 	const u8 *mac;
247 
248 	pdata->iobase = dev_read_addr(dev);
249 
250 	mac = dev_read_u8_array_ptr(dev, "fake-host-hwaddr", ARP_HLEN);
251 	if (!mac) {
252 		printf("'fake-host-hwaddr' is missing from the DT\n");
253 		return -EINVAL;
254 	}
255 	memcpy(priv->fake_host_hwaddr, mac, ARP_HLEN);
256 	priv->disabled = false;
257 
258 	return 0;
259 }
260 
261 static const struct udevice_id sb_eth_ids[] = {
262 	{ .compatible = "sandbox,eth" },
263 	{ }
264 };
265 
266 U_BOOT_DRIVER(eth_sandbox) = {
267 	.name	= "eth_sandbox",
268 	.id	= UCLASS_ETH,
269 	.of_match = sb_eth_ids,
270 	.ofdata_to_platdata = sb_eth_ofdata_to_platdata,
271 	.remove	= sb_eth_remove,
272 	.ops	= &sb_eth_ops,
273 	.priv_auto_alloc_size = sizeof(struct eth_sandbox_priv),
274 	.platdata_auto_alloc_size = sizeof(struct eth_pdata),
275 };
276