xref: /openbmc/u-boot/drivers/net/sandbox-raw.c (revision c9e2caff)
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 <asm/eth-raw-os.h>
10 #include <common.h>
11 #include <dm.h>
12 #include <malloc.h>
13 #include <net.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 static int reply_arp;
18 static struct in_addr arp_ip;
19 
20 static int sb_eth_raw_start(struct udevice *dev)
21 {
22 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
23 	struct eth_pdata *pdata = dev_get_platdata(dev);
24 	int ret;
25 
26 	debug("eth_sandbox_raw: Start\n");
27 
28 	ret = sandbox_eth_raw_os_start(priv, pdata->enetaddr);
29 	if (priv->local) {
30 		env_set("ipaddr", "127.0.0.1");
31 		env_set("serverip", "127.0.0.1");
32 		net_ip = string_to_ip("127.0.0.1");
33 		net_server_ip = net_ip;
34 	}
35 	return ret;
36 }
37 
38 static int sb_eth_raw_send(struct udevice *dev, void *packet, int length)
39 {
40 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
41 
42 	debug("eth_sandbox_raw: Send packet %d\n", length);
43 
44 	if (priv->local) {
45 		struct ethernet_hdr *eth = packet;
46 
47 		if (ntohs(eth->et_protlen) == PROT_ARP) {
48 			struct arp_hdr *arp = packet + ETHER_HDR_SIZE;
49 
50 			/**
51 			 * localhost works on a higher-level API in Linux than
52 			 * ARP packets, so fake it
53 			 */
54 			arp_ip = net_read_ip(&arp->ar_tpa);
55 			reply_arp = 1;
56 			return 0;
57 		}
58 		packet += ETHER_HDR_SIZE;
59 		length -= ETHER_HDR_SIZE;
60 	}
61 	return sandbox_eth_raw_os_send(packet, length, priv);
62 }
63 
64 static int sb_eth_raw_recv(struct udevice *dev, int flags, uchar **packetp)
65 {
66 	struct eth_pdata *pdata = dev_get_platdata(dev);
67 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
68 	int retval = 0;
69 	int length;
70 
71 	if (reply_arp) {
72 		struct arp_hdr *arp = (void *)net_rx_packets[0] +
73 			ETHER_HDR_SIZE;
74 
75 		/*
76 		 * Fake an ARP response. The u-boot network stack is sending an
77 		 * ARP request (to find the MAC address to address the actual
78 		 * packet to) and requires an ARP response to continue. Since
79 		 * this is the localhost interface, there is no Etherent level
80 		 * traffic at all, so there is no way to send an ARP request or
81 		 * to get a response. For this reason we fake the response to
82 		 * make the u-boot network stack happy.
83 		 */
84 		arp->ar_hrd = htons(ARP_ETHER);
85 		arp->ar_pro = htons(PROT_IP);
86 		arp->ar_hln = ARP_HLEN;
87 		arp->ar_pln = ARP_PLEN;
88 		arp->ar_op = htons(ARPOP_REPLY);
89 		/* Any non-zero MAC address will work */
90 		memset(&arp->ar_sha, 0x01, ARP_HLEN);
91 		/* Use whatever IP we were looking for (always 127.0.0.1?) */
92 		net_write_ip(&arp->ar_spa, arp_ip);
93 		memcpy(&arp->ar_tha, pdata->enetaddr, ARP_HLEN);
94 		net_write_ip(&arp->ar_tpa, net_ip);
95 		length = ARP_HDR_SIZE;
96 	} else {
97 		/* If local, the Ethernet header won't be included; skip it */
98 		uchar *pktptr = priv->local ?
99 			net_rx_packets[0] + ETHER_HDR_SIZE : net_rx_packets[0];
100 
101 		retval = sandbox_eth_raw_os_recv(pktptr, &length, priv);
102 	}
103 
104 	if (!retval && length) {
105 		if (priv->local) {
106 			struct ethernet_hdr *eth = (void *)net_rx_packets[0];
107 
108 			/* Fill in enough of the missing Ethernet header */
109 			memcpy(eth->et_dest, pdata->enetaddr, ARP_HLEN);
110 			memset(eth->et_src, 0x01, ARP_HLEN);
111 			eth->et_protlen = htons(reply_arp ? PROT_ARP : PROT_IP);
112 			reply_arp = 0;
113 			length += ETHER_HDR_SIZE;
114 		}
115 
116 		debug("eth_sandbox_raw: received packet %d\n",
117 		      length);
118 		*packetp = net_rx_packets[0];
119 		return length;
120 	}
121 	return retval;
122 }
123 
124 static void sb_eth_raw_stop(struct udevice *dev)
125 {
126 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
127 
128 	debug("eth_sandbox_raw: Stop\n");
129 
130 	sandbox_eth_raw_os_stop(priv);
131 }
132 
133 static const struct eth_ops sb_eth_raw_ops = {
134 	.start			= sb_eth_raw_start,
135 	.send			= sb_eth_raw_send,
136 	.recv			= sb_eth_raw_recv,
137 	.stop			= sb_eth_raw_stop,
138 };
139 
140 static int sb_eth_raw_ofdata_to_platdata(struct udevice *dev)
141 {
142 	struct eth_pdata *pdata = dev_get_platdata(dev);
143 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
144 	const char *ifname;
145 	u32 local;
146 	int ret;
147 
148 	pdata->iobase = dev_read_addr(dev);
149 
150 	ifname = dev_read_string(dev, "host-raw-interface");
151 	if (ifname) {
152 		strncpy(priv->host_ifname, ifname, IFNAMSIZ);
153 		printf(": Using %s from DT\n", priv->host_ifname);
154 	}
155 	if (dev_read_u32(dev, "host-raw-interface-idx",
156 			 &priv->host_ifindex) < 0) {
157 		priv->host_ifindex = 0;
158 	} else {
159 		ret = sandbox_eth_raw_os_idx_to_name(priv);
160 		if (ret < 0)
161 			return ret;
162 		printf(": Using interface index %d from DT (%s)\n",
163 		       priv->host_ifindex, priv->host_ifname);
164 	}
165 
166 	local = sandbox_eth_raw_os_is_local(priv->host_ifname);
167 	if (local < 0)
168 		return local;
169 	priv->local = local;
170 
171 	return 0;
172 }
173 
174 static const struct udevice_id sb_eth_raw_ids[] = {
175 	{ .compatible = "sandbox,eth-raw" },
176 	{ }
177 };
178 
179 U_BOOT_DRIVER(eth_sandbox_raw) = {
180 	.name	= "eth_sandbox_raw",
181 	.id	= UCLASS_ETH,
182 	.of_match = sb_eth_raw_ids,
183 	.ofdata_to_platdata = sb_eth_raw_ofdata_to_platdata,
184 	.ops	= &sb_eth_raw_ops,
185 	.priv_auto_alloc_size = sizeof(struct eth_sandbox_raw_priv),
186 	.platdata_auto_alloc_size = sizeof(struct eth_pdata),
187 };
188