xref: /openbmc/u-boot/drivers/net/sandbox-raw.c (revision 12308b12)
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 	const char *interface;
25 
26 	debug("eth_sandbox_raw: Start\n");
27 
28 	interface = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
29 					    "host-raw-interface", NULL);
30 	if (interface == NULL)
31 		return -EINVAL;
32 
33 	if (strcmp(interface, "lo") == 0) {
34 		priv->local = 1;
35 		env_set("ipaddr", "127.0.0.1");
36 		env_set("serverip", "127.0.0.1");
37 	}
38 	return sandbox_eth_raw_os_start(interface, pdata->enetaddr, priv);
39 }
40 
41 static int sb_eth_raw_send(struct udevice *dev, void *packet, int length)
42 {
43 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
44 
45 	debug("eth_sandbox_raw: Send packet %d\n", length);
46 
47 	if (priv->local) {
48 		struct ethernet_hdr *eth = packet;
49 
50 		if (ntohs(eth->et_protlen) == PROT_ARP) {
51 			struct arp_hdr *arp = packet + ETHER_HDR_SIZE;
52 
53 			/**
54 			 * localhost works on a higher-level API in Linux than
55 			 * ARP packets, so fake it
56 			 */
57 			arp_ip = net_read_ip(&arp->ar_tpa);
58 			reply_arp = 1;
59 			return 0;
60 		}
61 		packet += ETHER_HDR_SIZE;
62 		length -= ETHER_HDR_SIZE;
63 	}
64 	return sandbox_eth_raw_os_send(packet, length, priv);
65 }
66 
67 static int sb_eth_raw_recv(struct udevice *dev, int flags, uchar **packetp)
68 {
69 	struct eth_pdata *pdata = dev_get_platdata(dev);
70 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
71 	int retval = 0;
72 	int length;
73 
74 	if (reply_arp) {
75 		struct arp_hdr *arp = (void *)net_rx_packets[0] +
76 			ETHER_HDR_SIZE;
77 
78 		/*
79 		 * Fake an ARP response. The u-boot network stack is sending an
80 		 * ARP request (to find the MAC address to address the actual
81 		 * packet to) and requires an ARP response to continue. Since
82 		 * this is the localhost interface, there is no Etherent level
83 		 * traffic at all, so there is no way to send an ARP request or
84 		 * to get a response. For this reason we fake the response to
85 		 * make the u-boot network stack happy.
86 		 */
87 		arp->ar_hrd = htons(ARP_ETHER);
88 		arp->ar_pro = htons(PROT_IP);
89 		arp->ar_hln = ARP_HLEN;
90 		arp->ar_pln = ARP_PLEN;
91 		arp->ar_op = htons(ARPOP_REPLY);
92 		/* Any non-zero MAC address will work */
93 		memset(&arp->ar_sha, 0x01, ARP_HLEN);
94 		/* Use whatever IP we were looking for (always 127.0.0.1?) */
95 		net_write_ip(&arp->ar_spa, arp_ip);
96 		memcpy(&arp->ar_tha, pdata->enetaddr, ARP_HLEN);
97 		net_write_ip(&arp->ar_tpa, net_ip);
98 		length = ARP_HDR_SIZE;
99 	} else {
100 		/* If local, the Ethernet header won't be included; skip it */
101 		uchar *pktptr = priv->local ?
102 			net_rx_packets[0] + ETHER_HDR_SIZE : net_rx_packets[0];
103 
104 		retval = sandbox_eth_raw_os_recv(pktptr, &length, priv);
105 	}
106 
107 	if (!retval && length) {
108 		if (priv->local) {
109 			struct ethernet_hdr *eth = (void *)net_rx_packets[0];
110 
111 			/* Fill in enough of the missing Ethernet header */
112 			memcpy(eth->et_dest, pdata->enetaddr, ARP_HLEN);
113 			memset(eth->et_src, 0x01, ARP_HLEN);
114 			eth->et_protlen = htons(reply_arp ? PROT_ARP : PROT_IP);
115 			reply_arp = 0;
116 			length += ETHER_HDR_SIZE;
117 		}
118 
119 		debug("eth_sandbox_raw: received packet %d\n",
120 		      length);
121 		*packetp = net_rx_packets[0];
122 		return length;
123 	}
124 	return retval;
125 }
126 
127 static void sb_eth_raw_stop(struct udevice *dev)
128 {
129 	struct eth_sandbox_raw_priv *priv = dev_get_priv(dev);
130 
131 	debug("eth_sandbox_raw: Stop\n");
132 
133 	sandbox_eth_raw_os_stop(priv);
134 }
135 
136 static const struct eth_ops sb_eth_raw_ops = {
137 	.start			= sb_eth_raw_start,
138 	.send			= sb_eth_raw_send,
139 	.recv			= sb_eth_raw_recv,
140 	.stop			= sb_eth_raw_stop,
141 };
142 
143 static int sb_eth_raw_ofdata_to_platdata(struct udevice *dev)
144 {
145 	struct eth_pdata *pdata = dev_get_platdata(dev);
146 
147 	pdata->iobase = devfdt_get_addr(dev);
148 	return 0;
149 }
150 
151 static const struct udevice_id sb_eth_raw_ids[] = {
152 	{ .compatible = "sandbox,eth-raw" },
153 	{ }
154 };
155 
156 U_BOOT_DRIVER(eth_sandbox_raw) = {
157 	.name	= "eth_sandbox_raw",
158 	.id	= UCLASS_ETH,
159 	.of_match = sb_eth_raw_ids,
160 	.ofdata_to_platdata = sb_eth_raw_ofdata_to_platdata,
161 	.ops	= &sb_eth_raw_ops,
162 	.priv_auto_alloc_size = sizeof(struct eth_sandbox_raw_priv),
163 	.platdata_auto_alloc_size = sizeof(struct eth_pdata),
164 };
165