1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2004
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  */
6 
7 #include <command.h>
8 #include <env.h>
9 #include <log.h>
10 #include <stdio_dev.h>
11 #include <net.h>
12 #include <vsprintf.h>
13 
14 #ifndef CFG_NETCONSOLE_BUFFER_SIZE
15 #define CFG_NETCONSOLE_BUFFER_SIZE 512
16 #endif
17 
18 static char input_buffer[CFG_NETCONSOLE_BUFFER_SIZE];
19 static int input_size; /* char count in input buffer */
20 static int input_offset; /* offset to valid chars in input buffer */
21 static int input_recursion;
22 static int output_recursion;
23 static int net_timeout;
24 static uchar nc_ether[6]; /* server enet address */
25 static struct in_addr nc_ip; /* server ip */
26 static short nc_out_port; /* target output port */
27 static short nc_in_port; /* source input port */
28 static const char *output_packet; /* used by first send udp */
29 static int output_packet_len;
30 /*
31  * Start with a default last protocol.
32  * We are only interested in NETCONS or not.
33  */
34 enum proto_t net_loop_last_protocol = BOOTP;
35 
nc_wait_arp_handler(uchar * pkt,unsigned dest,struct in_addr sip,unsigned src,unsigned len)36 static void nc_wait_arp_handler(uchar *pkt, unsigned dest,
37 				 struct in_addr sip, unsigned src,
38 				 unsigned len)
39 {
40 	net_set_state(NETLOOP_SUCCESS); /* got arp reply - quit net loop */
41 }
42 
nc_handler(uchar * pkt,unsigned dest,struct in_addr sip,unsigned src,unsigned len)43 static void nc_handler(uchar *pkt, unsigned dest, struct in_addr sip,
44 		       unsigned src, unsigned len)
45 {
46 	if (input_size)
47 		net_set_state(NETLOOP_SUCCESS); /* got input - quit net loop */
48 }
49 
nc_timeout_handler(void)50 static void nc_timeout_handler(void)
51 {
52 	net_set_state(NETLOOP_SUCCESS);
53 }
54 
is_broadcast(struct in_addr ip)55 static int is_broadcast(struct in_addr ip)
56 {
57 	static struct in_addr netmask;
58 	static struct in_addr our_ip;
59 	static int env_changed_id;
60 	int env_id = env_get_id();
61 
62 	/* update only when the environment has changed */
63 	if (env_changed_id != env_id) {
64 		netmask = string_to_ip(env_get("netmask"));
65 		our_ip = string_to_ip(env_get("ipaddr"));
66 
67 		env_changed_id = env_id;
68 	}
69 
70 	return (ip.s_addr == ~0 || /* 255.255.255.255 (global bcast) */
71 		((netmask.s_addr & our_ip.s_addr) ==
72 		 (netmask.s_addr & ip.s_addr) && /* on the same net and */
73 		 (netmask.s_addr | ip.s_addr) == ~0)); /* bcast to our net */
74 }
75 
refresh_settings_from_env(void)76 static int refresh_settings_from_env(void)
77 {
78 	const char *p;
79 	static int env_changed_id;
80 	int env_id = env_get_id();
81 
82 	/* update only when the environment has changed */
83 	if (env_changed_id != env_id) {
84 		char *tmp = env_get("ncip");
85 		if (tmp) {
86 			nc_ip = string_to_ip(tmp);
87 			if (!nc_ip.s_addr)
88 				return -1;	/* ncip is 0.0.0.0 */
89 			p = strchr(tmp, ':');
90 			if (p != NULL) {
91 				nc_out_port = dectoul(p + 1, NULL);
92 				nc_in_port = nc_out_port;
93 			}
94 		} else {
95 			nc_ip.s_addr = ~0; /* ncip is not set, so broadcast */
96 		}
97 
98 		p = env_get("ncoutport");
99 		if (p != NULL)
100 			nc_out_port = dectoul(p, NULL);
101 		p = env_get("ncinport");
102 		if (p != NULL)
103 			nc_in_port = dectoul(p, NULL);
104 
105 		if (is_broadcast(nc_ip))
106 			/* broadcast MAC address */
107 			memset(nc_ether, 0xff, sizeof(nc_ether));
108 		else
109 			/* force arp request */
110 			memset(nc_ether, 0, sizeof(nc_ether));
111 	}
112 	return 0;
113 }
114 
115 /**
116  * Called from net_loop in net/net.c before each packet
117  */
nc_start(void)118 void nc_start(void)
119 {
120 	refresh_settings_from_env();
121 	if (!output_packet_len || memcmp(nc_ether, net_null_ethaddr, 6)) {
122 		/* going to check for input packet */
123 		net_set_udp_handler(nc_handler);
124 		net_set_timeout_handler(net_timeout, nc_timeout_handler);
125 	} else {
126 		/* send arp request */
127 		uchar *pkt;
128 		net_set_arp_handler(nc_wait_arp_handler);
129 		pkt = (uchar *)net_tx_packet + net_eth_hdr_size() +
130 			IP_UDP_HDR_SIZE;
131 		memcpy(pkt, output_packet, output_packet_len);
132 		net_send_udp_packet(nc_ether, nc_ip, nc_out_port, nc_in_port,
133 				    output_packet_len);
134 	}
135 }
136 
nc_input_packet(uchar * pkt,struct in_addr src_ip,unsigned dest_port,unsigned src_port,unsigned len)137 int nc_input_packet(uchar *pkt, struct in_addr src_ip, unsigned dest_port,
138 	unsigned src_port, unsigned len)
139 {
140 	int end, chunk;
141 
142 	if (dest_port != nc_in_port || !len)
143 		return 0; /* not for us */
144 
145 	if (src_ip.s_addr != nc_ip.s_addr && !is_broadcast(nc_ip))
146 		return 0; /* not from our client */
147 
148 	debug_cond(DEBUG_DEV_PKT, "input: \"%*.*s\"\n", len, len, pkt);
149 
150 	if (input_size == sizeof(input_buffer))
151 		return 1; /* no space */
152 	if (len > sizeof(input_buffer) - input_size)
153 		len = sizeof(input_buffer) - input_size;
154 
155 	end = input_offset + input_size;
156 	if (end >= sizeof(input_buffer))
157 		end -= sizeof(input_buffer);
158 
159 	chunk = len;
160 	/* Check if packet will wrap in input_buffer */
161 	if (end + len >= sizeof(input_buffer)) {
162 		chunk = sizeof(input_buffer) - end;
163 		/* Copy the second part of the pkt to start of input_buffer */
164 		memcpy(input_buffer, pkt + chunk, len - chunk);
165 	}
166 	/* Copy first (or only) part of pkt after end of current valid input*/
167 	memcpy(input_buffer + end, pkt, chunk);
168 
169 	input_size += len;
170 
171 	return 1;
172 }
173 
nc_send_packet(const char * buf,int len)174 static void nc_send_packet(const char *buf, int len)
175 {
176 	struct udevice *eth;
177 	int inited = 0;
178 	uchar *pkt;
179 	uchar *ether;
180 	struct in_addr ip;
181 
182 	debug_cond(DEBUG_DEV_PKT, "output: \"%*.*s\"\n", len, len, buf);
183 
184 	eth = eth_get_dev();
185 	if (eth == NULL)
186 		return;
187 
188 	if (!memcmp(nc_ether, net_null_ethaddr, 6)) {
189 		if (eth_is_active(eth))
190 			return;	/* inside net loop */
191 		output_packet = buf;
192 		output_packet_len = len;
193 		input_recursion = 1;
194 		net_loop(NETCONS); /* wait for arp reply and send packet */
195 		input_recursion = 0;
196 		output_packet_len = 0;
197 		return;
198 	}
199 
200 	if (!eth_is_active(eth)) {
201 		if (eth_is_on_demand_init()) {
202 			if (eth_init() < 0)
203 				return;
204 			eth_set_last_protocol(NETCONS);
205 		} else {
206 			eth_init_state_only();
207 		}
208 
209 		inited = 1;
210 	}
211 	pkt = (uchar *)net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE;
212 	memcpy(pkt, buf, len);
213 	ether = nc_ether;
214 	ip = nc_ip;
215 	net_send_udp_packet(ether, ip, nc_out_port, nc_in_port, len);
216 
217 	if (inited) {
218 		if (eth_is_on_demand_init())
219 			eth_halt();
220 		else
221 			eth_halt_state_only();
222 	}
223 }
224 
nc_stdio_start(struct stdio_dev * dev)225 static int nc_stdio_start(struct stdio_dev *dev)
226 {
227 	int retval;
228 
229 	nc_out_port = 6666; /* default port */
230 	nc_in_port = nc_out_port;
231 
232 	retval = refresh_settings_from_env();
233 	if (retval != 0)
234 		return retval;
235 
236 	/*
237 	 * Initialize the static IP settings and buffer pointers
238 	 * incase we call net_send_udp_packet before net_loop
239 	 */
240 	net_init();
241 
242 	return 0;
243 }
244 
nc_stdio_putc(struct stdio_dev * dev,char c)245 static void nc_stdio_putc(struct stdio_dev *dev, char c)
246 {
247 	if (output_recursion)
248 		return;
249 	output_recursion = 1;
250 
251 	nc_send_packet(&c, 1);
252 
253 	output_recursion = 0;
254 }
255 
nc_stdio_puts(struct stdio_dev * dev,const char * s)256 static void nc_stdio_puts(struct stdio_dev *dev, const char *s)
257 {
258 	int len;
259 
260 	if (output_recursion)
261 		return;
262 	output_recursion = 1;
263 
264 	len = strlen(s);
265 	while (len) {
266 		int send_len = min(len, (int)sizeof(input_buffer));
267 		nc_send_packet(s, send_len);
268 		len -= send_len;
269 		s += send_len;
270 	}
271 
272 	output_recursion = 0;
273 }
274 
nc_stdio_getc(struct stdio_dev * dev)275 static int nc_stdio_getc(struct stdio_dev *dev)
276 {
277 	uchar c;
278 
279 	input_recursion = 1;
280 
281 	net_timeout = 0;	/* no timeout */
282 	while (!input_size)
283 		net_loop(NETCONS);
284 
285 	input_recursion = 0;
286 
287 	c = input_buffer[input_offset++];
288 
289 	if (input_offset >= sizeof(input_buffer))
290 		input_offset -= sizeof(input_buffer);
291 	input_size--;
292 
293 	return c;
294 }
295 
nc_stdio_tstc(struct stdio_dev * dev)296 static int nc_stdio_tstc(struct stdio_dev *dev)
297 {
298 	struct udevice *eth;
299 
300 	if (input_recursion)
301 		return 0;
302 
303 	if (input_size)
304 		return 1;
305 
306 	eth = eth_get_dev();
307 	if (eth_is_active(eth))
308 		return 0;	/* inside net loop */
309 
310 	input_recursion = 1;
311 
312 	net_timeout = 1;
313 	net_loop(NETCONS);	/* kind of poll */
314 
315 	input_recursion = 0;
316 
317 	return input_size != 0;
318 }
319 
drv_nc_init(void)320 int drv_nc_init(void)
321 {
322 	struct stdio_dev dev;
323 	int rc;
324 
325 	memset(&dev, 0, sizeof(dev));
326 
327 	strcpy(dev.name, "nc");
328 	dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
329 	dev.start = nc_stdio_start;
330 	dev.putc = nc_stdio_putc;
331 	dev.puts = nc_stdio_puts;
332 	dev.getc = nc_stdio_getc;
333 	dev.tstc = nc_stdio_tstc;
334 
335 	rc = stdio_register(&dev);
336 
337 	return (rc == 0) ? 1 : rc;
338 }
339