xref: /openbmc/u-boot/drivers/net/sandbox.c (revision d30ba231)
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  * recv_packet_buffer: buffer of the packet returned as received
23  * recv_packet_length: length of the packet returned as received
24  */
25 struct eth_sandbox_priv {
26 	uchar fake_host_hwaddr[ARP_HLEN];
27 	struct in_addr fake_host_ipaddr;
28 	uchar *recv_packet_buffer;
29 	int recv_packet_length;
30 };
31 
32 static bool disabled[8] = {false};
33 static bool skip_timeout;
34 
35 /*
36  * sandbox_eth_disable_response()
37  *
38  * index - The alias index (also DM seq number)
39  * disable - If non-zero, ignore sent packets and don't send mock response
40  */
41 void sandbox_eth_disable_response(int index, bool disable)
42 {
43 	disabled[index] = disable;
44 }
45 
46 /*
47  * sandbox_eth_skip_timeout()
48  *
49  * When the first packet read is attempted, fast-forward time
50  */
51 void sandbox_eth_skip_timeout(void)
52 {
53 	skip_timeout = true;
54 }
55 
56 static int sb_eth_start(struct udevice *dev)
57 {
58 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
59 
60 	debug("eth_sandbox: Start\n");
61 
62 	priv->recv_packet_buffer = net_rx_packets[0];
63 
64 	return 0;
65 }
66 
67 static int sb_eth_send(struct udevice *dev, void *packet, int length)
68 {
69 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
70 	struct ethernet_hdr *eth = packet;
71 
72 	debug("eth_sandbox: Send packet %d\n", length);
73 
74 	if (dev->seq >= 0 && dev->seq < ARRAY_SIZE(disabled) &&
75 	    disabled[dev->seq])
76 		return 0;
77 
78 	if (ntohs(eth->et_protlen) == PROT_ARP) {
79 		struct arp_hdr *arp = packet + ETHER_HDR_SIZE;
80 
81 		if (ntohs(arp->ar_op) == ARPOP_REQUEST) {
82 			struct ethernet_hdr *eth_recv;
83 			struct arp_hdr *arp_recv;
84 
85 			/* store this as the assumed IP of the fake host */
86 			priv->fake_host_ipaddr = net_read_ip(&arp->ar_tpa);
87 			/* Formulate a fake response */
88 			eth_recv = (void *)priv->recv_packet_buffer;
89 			memcpy(eth_recv->et_dest, eth->et_src, ARP_HLEN);
90 			memcpy(eth_recv->et_src, priv->fake_host_hwaddr,
91 			       ARP_HLEN);
92 			eth_recv->et_protlen = htons(PROT_ARP);
93 
94 			arp_recv = (void *)priv->recv_packet_buffer +
95 				ETHER_HDR_SIZE;
96 			arp_recv->ar_hrd = htons(ARP_ETHER);
97 			arp_recv->ar_pro = htons(PROT_IP);
98 			arp_recv->ar_hln = ARP_HLEN;
99 			arp_recv->ar_pln = ARP_PLEN;
100 			arp_recv->ar_op = htons(ARPOP_REPLY);
101 			memcpy(&arp_recv->ar_sha, priv->fake_host_hwaddr,
102 			       ARP_HLEN);
103 			net_write_ip(&arp_recv->ar_spa, priv->fake_host_ipaddr);
104 			memcpy(&arp_recv->ar_tha, &arp->ar_sha, ARP_HLEN);
105 			net_copy_ip(&arp_recv->ar_tpa, &arp->ar_spa);
106 
107 			priv->recv_packet_length = ETHER_HDR_SIZE +
108 				ARP_HDR_SIZE;
109 		}
110 	} else if (ntohs(eth->et_protlen) == PROT_IP) {
111 		struct ip_udp_hdr *ip = packet + ETHER_HDR_SIZE;
112 
113 		if (ip->ip_p == IPPROTO_ICMP) {
114 			struct icmp_hdr *icmp = (struct icmp_hdr *)&ip->udp_src;
115 
116 			if (icmp->type == ICMP_ECHO_REQUEST) {
117 				struct ethernet_hdr *eth_recv;
118 				struct ip_udp_hdr *ipr;
119 				struct icmp_hdr *icmpr;
120 
121 				/* reply to the ping */
122 				memcpy(priv->recv_packet_buffer, packet,
123 				       length);
124 				eth_recv = (void *)priv->recv_packet_buffer;
125 				ipr = (void *)priv->recv_packet_buffer +
126 					ETHER_HDR_SIZE;
127 				icmpr = (struct icmp_hdr *)&ipr->udp_src;
128 				memcpy(eth_recv->et_dest, eth->et_src,
129 				       ARP_HLEN);
130 				memcpy(eth_recv->et_src, priv->fake_host_hwaddr,
131 				       ARP_HLEN);
132 				ipr->ip_sum = 0;
133 				ipr->ip_off = 0;
134 				net_copy_ip((void *)&ipr->ip_dst, &ip->ip_src);
135 				net_write_ip((void *)&ipr->ip_src,
136 					     priv->fake_host_ipaddr);
137 				ipr->ip_sum = compute_ip_checksum(ipr,
138 					IP_HDR_SIZE);
139 
140 				icmpr->type = ICMP_ECHO_REPLY;
141 				icmpr->checksum = 0;
142 				icmpr->checksum = compute_ip_checksum(icmpr,
143 					ICMP_HDR_SIZE);
144 
145 				priv->recv_packet_length = length;
146 			}
147 		}
148 	}
149 
150 	return 0;
151 }
152 
153 static int sb_eth_recv(struct udevice *dev, int flags, uchar **packetp)
154 {
155 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
156 
157 	if (skip_timeout) {
158 		sandbox_timer_add_offset(11000UL);
159 		skip_timeout = false;
160 	}
161 
162 	if (priv->recv_packet_length) {
163 		int lcl_recv_packet_length = priv->recv_packet_length;
164 
165 		debug("eth_sandbox: received packet %d\n",
166 		      priv->recv_packet_length);
167 		priv->recv_packet_length = 0;
168 		*packetp = priv->recv_packet_buffer;
169 		return lcl_recv_packet_length;
170 	}
171 	return 0;
172 }
173 
174 static void sb_eth_stop(struct udevice *dev)
175 {
176 	debug("eth_sandbox: Stop\n");
177 }
178 
179 static int sb_eth_write_hwaddr(struct udevice *dev)
180 {
181 	struct eth_pdata *pdata = dev_get_platdata(dev);
182 
183 	debug("eth_sandbox %s: Write HW ADDR - %pM\n", dev->name,
184 	      pdata->enetaddr);
185 	return 0;
186 }
187 
188 static const struct eth_ops sb_eth_ops = {
189 	.start			= sb_eth_start,
190 	.send			= sb_eth_send,
191 	.recv			= sb_eth_recv,
192 	.stop			= sb_eth_stop,
193 	.write_hwaddr		= sb_eth_write_hwaddr,
194 };
195 
196 static int sb_eth_remove(struct udevice *dev)
197 {
198 	return 0;
199 }
200 
201 static int sb_eth_ofdata_to_platdata(struct udevice *dev)
202 {
203 	struct eth_pdata *pdata = dev_get_platdata(dev);
204 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
205 	const u8 *mac;
206 
207 	pdata->iobase = dev_read_addr(dev);
208 
209 	mac = dev_read_u8_array_ptr(dev, "fake-host-hwaddr", ARP_HLEN);
210 	if (!mac) {
211 		printf("'fake-host-hwaddr' is missing from the DT\n");
212 		return -EINVAL;
213 	}
214 	memcpy(priv->fake_host_hwaddr, mac, ARP_HLEN);
215 
216 	return 0;
217 }
218 
219 static const struct udevice_id sb_eth_ids[] = {
220 	{ .compatible = "sandbox,eth" },
221 	{ }
222 };
223 
224 U_BOOT_DRIVER(eth_sandbox) = {
225 	.name	= "eth_sandbox",
226 	.id	= UCLASS_ETH,
227 	.of_match = sb_eth_ids,
228 	.ofdata_to_platdata = sb_eth_ofdata_to_platdata,
229 	.remove	= sb_eth_remove,
230 	.ops	= &sb_eth_ops,
231 	.priv_auto_alloc_size = sizeof(struct eth_sandbox_priv),
232 	.platdata_auto_alloc_size = sizeof(struct eth_pdata),
233 };
234