xref: /openbmc/u-boot/drivers/net/sandbox.c (revision ed09a554)
1 /*
2  * Copyright (c) 2015 National Instruments
3  *
4  * (C) Copyright 2015
5  * Joe Hershberger <joe.hershberger@ni.com>
6  *
7  * SPDX-License-Identifier:	GPL-2.0
8  */
9 
10 #include <common.h>
11 #include <dm.h>
12 #include <malloc.h>
13 #include <net.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 
34 /*
35  * sandbox_eth_disable_response()
36  *
37  * index - The alias index (also DM seq number)
38  * disable - If non-zero, ignore sent packets and don't send mock response
39  */
40 void sandbox_eth_disable_response(int index, bool disable)
41 {
42 	disabled[index] = disable;
43 }
44 
45 static int sb_eth_start(struct udevice *dev)
46 {
47 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
48 
49 	debug("eth_sandbox: Start\n");
50 
51 	fdtdec_get_byte_array(gd->fdt_blob, dev->of_offset, "fake-host-hwaddr",
52 			      priv->fake_host_hwaddr, ARP_HLEN);
53 	priv->recv_packet_buffer = net_rx_packets[0];
54 	return 0;
55 }
56 
57 static int sb_eth_send(struct udevice *dev, void *packet, int length)
58 {
59 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
60 	struct ethernet_hdr *eth = packet;
61 
62 	debug("eth_sandbox: Send packet %d\n", length);
63 
64 	if (dev->seq >= 0 && dev->seq < ARRAY_SIZE(disabled) &&
65 	    disabled[dev->seq])
66 		return 0;
67 
68 	if (ntohs(eth->et_protlen) == PROT_ARP) {
69 		struct arp_hdr *arp = packet + ETHER_HDR_SIZE;
70 
71 		if (ntohs(arp->ar_op) == ARPOP_REQUEST) {
72 			struct ethernet_hdr *eth_recv;
73 			struct arp_hdr *arp_recv;
74 
75 			/* store this as the assumed IP of the fake host */
76 			priv->fake_host_ipaddr = net_read_ip(&arp->ar_tpa);
77 			/* Formulate a fake response */
78 			eth_recv = (void *)priv->recv_packet_buffer;
79 			memcpy(eth_recv->et_dest, eth->et_src, ARP_HLEN);
80 			memcpy(eth_recv->et_src, priv->fake_host_hwaddr,
81 			       ARP_HLEN);
82 			eth_recv->et_protlen = htons(PROT_ARP);
83 
84 			arp_recv = (void *)priv->recv_packet_buffer +
85 				ETHER_HDR_SIZE;
86 			arp_recv->ar_hrd = htons(ARP_ETHER);
87 			arp_recv->ar_pro = htons(PROT_IP);
88 			arp_recv->ar_hln = ARP_HLEN;
89 			arp_recv->ar_pln = ARP_PLEN;
90 			arp_recv->ar_op = htons(ARPOP_REPLY);
91 			memcpy(&arp_recv->ar_sha, priv->fake_host_hwaddr,
92 			       ARP_HLEN);
93 			net_write_ip(&arp_recv->ar_spa, priv->fake_host_ipaddr);
94 			memcpy(&arp_recv->ar_tha, &arp->ar_sha, ARP_HLEN);
95 			net_copy_ip(&arp_recv->ar_tpa, &arp->ar_spa);
96 
97 			priv->recv_packet_length = ETHER_HDR_SIZE +
98 				ARP_HDR_SIZE;
99 		}
100 	} else if (ntohs(eth->et_protlen) == PROT_IP) {
101 		struct ip_udp_hdr *ip = packet + ETHER_HDR_SIZE;
102 
103 		if (ip->ip_p == IPPROTO_ICMP) {
104 			struct icmp_hdr *icmp = (struct icmp_hdr *)&ip->udp_src;
105 
106 			if (icmp->type == ICMP_ECHO_REQUEST) {
107 				struct ethernet_hdr *eth_recv;
108 				struct ip_udp_hdr *ipr;
109 				struct icmp_hdr *icmpr;
110 
111 				/* reply to the ping */
112 				memcpy(priv->recv_packet_buffer, packet,
113 				       length);
114 				eth_recv = (void *)priv->recv_packet_buffer;
115 				ipr = (void *)priv->recv_packet_buffer +
116 					ETHER_HDR_SIZE;
117 				icmpr = (struct icmp_hdr *)&ipr->udp_src;
118 				memcpy(eth_recv->et_dest, eth->et_src,
119 				       ARP_HLEN);
120 				memcpy(eth_recv->et_src, priv->fake_host_hwaddr,
121 				       ARP_HLEN);
122 				ipr->ip_sum = 0;
123 				ipr->ip_off = 0;
124 				net_copy_ip((void *)&ipr->ip_dst, &ip->ip_src);
125 				net_write_ip((void *)&ipr->ip_src,
126 					     priv->fake_host_ipaddr);
127 				ipr->ip_sum = compute_ip_checksum(ipr,
128 					IP_HDR_SIZE);
129 
130 				icmpr->type = ICMP_ECHO_REPLY;
131 				icmpr->checksum = 0;
132 				icmpr->checksum = compute_ip_checksum(icmpr,
133 					ICMP_HDR_SIZE);
134 
135 				priv->recv_packet_length = length;
136 			}
137 		}
138 	}
139 
140 	return 0;
141 }
142 
143 static int sb_eth_recv(struct udevice *dev, uchar **packetp)
144 {
145 	struct eth_sandbox_priv *priv = dev_get_priv(dev);
146 
147 	if (priv->recv_packet_length) {
148 		int lcl_recv_packet_length = priv->recv_packet_length;
149 
150 		debug("eth_sandbox: received packet %d\n",
151 		      priv->recv_packet_length);
152 		priv->recv_packet_length = 0;
153 		*packetp = priv->recv_packet_buffer;
154 		return lcl_recv_packet_length;
155 	}
156 	return 0;
157 }
158 
159 static void sb_eth_stop(struct udevice *dev)
160 {
161 	debug("eth_sandbox: Stop\n");
162 }
163 
164 static int sb_eth_write_hwaddr(struct udevice *dev)
165 {
166 	struct eth_pdata *pdata = dev_get_platdata(dev);
167 
168 	debug("eth_sandbox %s: Write HW ADDR - %pM\n", dev->name,
169 	      pdata->enetaddr);
170 	return 0;
171 }
172 
173 static const struct eth_ops sb_eth_ops = {
174 	.start			= sb_eth_start,
175 	.send			= sb_eth_send,
176 	.recv			= sb_eth_recv,
177 	.stop			= sb_eth_stop,
178 	.write_hwaddr		= sb_eth_write_hwaddr,
179 };
180 
181 static int sb_eth_remove(struct udevice *dev)
182 {
183 	return 0;
184 }
185 
186 static int sb_eth_ofdata_to_platdata(struct udevice *dev)
187 {
188 	struct eth_pdata *pdata = dev_get_platdata(dev);
189 
190 	pdata->iobase = dev_get_addr(dev);
191 	return 0;
192 }
193 
194 static const struct udevice_id sb_eth_ids[] = {
195 	{ .compatible = "sandbox,eth" },
196 	{ }
197 };
198 
199 U_BOOT_DRIVER(eth_sandbox) = {
200 	.name	= "eth_sandbox",
201 	.id	= UCLASS_ETH,
202 	.of_match = sb_eth_ids,
203 	.ofdata_to_platdata = sb_eth_ofdata_to_platdata,
204 	.remove	= sb_eth_remove,
205 	.ops	= &sb_eth_ops,
206 	.priv_auto_alloc_size = sizeof(struct eth_sandbox_priv),
207 	.platdata_auto_alloc_size = sizeof(struct eth_pdata),
208 };
209