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 <log.h>
10 #include <asm/eth-raw-os.h>
11 #include <dm.h>
12 #include <env.h>
13 #include <malloc.h>
14 #include <net.h>
15 #include <asm/global_data.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 static int reply_arp;
20 static struct in_addr arp_ip;
21 
sb_eth_raw_start(struct udevice * dev)22 static int sb_eth_raw_start(struct udevice *dev)
23 {
24 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
25 	struct eth_pdata *pdata = dev_get_plat(dev);
26 	int ret;
27 
28 	debug("eth_sandbox_raw: Start\n");
29 
30 	ret = sandbox_eth_raw_os_start(priv, pdata->enetaddr);
31 	if (priv->local) {
32 		env_set("ipaddr", "127.0.0.1");
33 		env_set("serverip", "127.0.0.1");
34 		net_ip = string_to_ip("127.0.0.1");
35 		net_server_ip = net_ip;
36 	}
37 	return ret;
38 }
39 
sb_eth_raw_send(struct udevice * dev,void * packet,int length)40 static int sb_eth_raw_send(struct udevice *dev, void *packet, int length)
41 {
42 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
43 
44 	debug("eth_sandbox_raw: Send packet %d\n", length);
45 
46 	if (priv->local) {
47 		struct ethernet_hdr *eth = packet;
48 
49 		if (ntohs(eth->et_protlen) == PROT_ARP) {
50 			struct arp_hdr *arp = packet + ETHER_HDR_SIZE;
51 
52 			/**
53 			 * localhost works on a higher-level API in Linux than
54 			 * ARP packets, so fake it
55 			 */
56 			arp_ip = net_read_ip(&arp->ar_tpa);
57 			reply_arp = 1;
58 			return 0;
59 		}
60 		packet += ETHER_HDR_SIZE;
61 		length -= ETHER_HDR_SIZE;
62 	}
63 	return sandbox_eth_raw_os_send(packet, length, priv);
64 }
65 
sb_eth_raw_recv(struct udevice * dev,int flags,uchar ** packetp)66 static int sb_eth_raw_recv(struct udevice *dev, int flags, uchar **packetp)
67 {
68 	struct eth_pdata *pdata = dev_get_plat(dev);
69 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
70 	int retval = 0;
71 	int length;
72 
73 	if (reply_arp) {
74 		struct arp_hdr *arp = (void *)net_rx_packets[0] +
75 			ETHER_HDR_SIZE;
76 
77 		/*
78 		 * Fake an ARP response. The u-boot network stack is sending an
79 		 * ARP request (to find the MAC address to address the actual
80 		 * packet to) and requires an ARP response to continue. Since
81 		 * this is the localhost interface, there is no Etherent level
82 		 * traffic at all, so there is no way to send an ARP request or
83 		 * to get a response. For this reason we fake the response to
84 		 * make the u-boot network stack happy.
85 		 */
86 		arp->ar_hrd = htons(ARP_ETHER);
87 		arp->ar_pro = htons(PROT_IP);
88 		arp->ar_hln = ARP_HLEN;
89 		arp->ar_pln = ARP_PLEN;
90 		arp->ar_op = htons(ARPOP_REPLY);
91 		/* Any non-zero MAC address will work */
92 		memset(&arp->ar_sha, 0x01, ARP_HLEN);
93 		/* Use whatever IP we were looking for (always 127.0.0.1?) */
94 		net_write_ip(&arp->ar_spa, arp_ip);
95 		memcpy(&arp->ar_tha, pdata->enetaddr, ARP_HLEN);
96 		net_write_ip(&arp->ar_tpa, net_ip);
97 		length = ARP_HDR_SIZE;
98 	} else {
99 		/* If local, the Ethernet header won't be included; skip it */
100 		uchar *pktptr = priv->local ?
101 			net_rx_packets[0] + ETHER_HDR_SIZE : net_rx_packets[0];
102 
103 		retval = sandbox_eth_raw_os_recv(pktptr, &length, priv);
104 	}
105 
106 	if (!retval && length) {
107 		if (priv->local) {
108 			struct ethernet_hdr *eth = (void *)net_rx_packets[0];
109 
110 			/* Fill in enough of the missing Ethernet header */
111 			memcpy(eth->et_dest, pdata->enetaddr, ARP_HLEN);
112 			memset(eth->et_src, 0x01, ARP_HLEN);
113 			eth->et_protlen = htons(reply_arp ? PROT_ARP : PROT_IP);
114 			reply_arp = 0;
115 			length += ETHER_HDR_SIZE;
116 		}
117 
118 		debug("eth_sandbox_raw: received packet %d\n",
119 		      length);
120 		*packetp = net_rx_packets[0];
121 		return length;
122 	}
123 	return retval;
124 }
125 
sb_eth_raw_stop(struct udevice * dev)126 static void sb_eth_raw_stop(struct udevice *dev)
127 {
128 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
129 
130 	debug("eth_sandbox_raw: Stop\n");
131 
132 	sandbox_eth_raw_os_stop(priv);
133 }
134 
sb_eth_raw_read_rom_hwaddr(struct udevice * dev)135 static int sb_eth_raw_read_rom_hwaddr(struct udevice *dev)
136 {
137 	struct eth_pdata *pdata = dev_get_plat(dev);
138 
139 	net_random_ethaddr(pdata->enetaddr);
140 
141 	return 0;
142 }
143 
144 static const struct eth_ops sb_eth_raw_ops = {
145 	.start			= sb_eth_raw_start,
146 	.send			= sb_eth_raw_send,
147 	.recv			= sb_eth_raw_recv,
148 	.stop			= sb_eth_raw_stop,
149 	.read_rom_hwaddr	= sb_eth_raw_read_rom_hwaddr,
150 };
151 
sb_eth_raw_of_to_plat(struct udevice * dev)152 static int sb_eth_raw_of_to_plat(struct udevice *dev)
153 {
154 	struct eth_pdata *pdata = dev_get_plat(dev);
155 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
156 	const char *ifname;
157 	int ret;
158 
159 	pdata->iobase = dev_read_addr(dev);
160 
161 	ifname = dev_read_string(dev, "host-raw-interface");
162 	if (ifname) {
163 		strlcpy(priv->host_ifname, ifname, IFNAMSIZ);
164 		printf(": Using %s from DT\n", priv->host_ifname);
165 	}
166 	if (dev_read_u32(dev, "host-raw-interface-idx",
167 			 &priv->host_ifindex) < 0) {
168 		priv->host_ifindex = 0;
169 	} else {
170 		ret = sandbox_eth_raw_os_idx_to_name(priv);
171 		if (ret < 0)
172 			return ret;
173 		printf(": Using interface index %d from DT (%s)\n",
174 		       priv->host_ifindex, priv->host_ifname);
175 	}
176 
177 	ret = sandbox_eth_raw_os_is_local(priv->host_ifname);
178 	if (ret < 0)
179 		return ret;
180 	priv->local = ret;
181 
182 	return 0;
183 }
184 
185 static const struct udevice_id sb_eth_raw_ids[] = {
186 	{ .compatible = "sandbox,eth-raw" },
187 	{ }
188 };
189 
190 U_BOOT_DRIVER(eth_sandbox_raw) = {
191 	.name	= "eth_sandbox_raw",
192 	.id	= UCLASS_ETH,
193 	.of_match = sb_eth_raw_ids,
194 	.of_to_plat = sb_eth_raw_of_to_plat,
195 	.ops	= &sb_eth_raw_ops,
196 	.priv_auto	= sizeof(struct eth_sandbox_raw_priv),
197 	.plat_auto	= sizeof(struct eth_pdata),
198 };
199