xref: /openbmc/linux/arch/um/drivers/net_user.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include <stddef.h>
7 #include <stdarg.h>
8 #include <unistd.h>
9 #include <stdio.h>
10 #include <errno.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <sys/socket.h>
14 #include <sys/wait.h>
15 #include "user.h"
16 #include "user_util.h"
17 #include "kern_util.h"
18 #include "net_user.h"
19 #include "helper.h"
20 #include "os.h"
21 
22 int tap_open_common(void *dev, char *gate_addr)
23 {
24 	int tap_addr[4];
25 
26 	if(gate_addr == NULL) return(0);
27 	if(sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
28 		  &tap_addr[1], &tap_addr[2], &tap_addr[3]) != 4){
29 		printk("Invalid tap IP address - '%s'\n", gate_addr);
30 		return(-EINVAL);
31 	}
32 	return(0);
33 }
34 
35 void tap_check_ips(char *gate_addr, char *eth_addr)
36 {
37 	int tap_addr[4];
38 
39 	if((gate_addr != NULL) &&
40 	   (sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
41 		   &tap_addr[1], &tap_addr[2], &tap_addr[3]) == 4) &&
42 	   (eth_addr[0] == tap_addr[0]) &&
43 	   (eth_addr[1] == tap_addr[1]) &&
44 	   (eth_addr[2] == tap_addr[2]) &&
45 	   (eth_addr[3] == tap_addr[3])){
46 		printk("The tap IP address and the UML eth IP address"
47 		       " must be different\n");
48 	}
49 }
50 
51 void read_output(int fd, char *output, int len)
52 {
53 	int remain, n, actual;
54 	char c;
55 
56 	if(output == NULL){
57 		output = &c;
58 		len = sizeof(c);
59 	}
60 
61 	*output = '\0';
62 	n = os_read_file(fd, &remain, sizeof(remain));
63 	if(n != sizeof(remain)){
64 		printk("read_output - read of length failed, err = %d\n", -n);
65 		return;
66 	}
67 
68 	while(remain != 0){
69 		n = (remain < len) ? remain : len;
70 		actual = os_read_file(fd, output, n);
71 		if(actual != n){
72 			printk("read_output - read of data failed, "
73 			       "err = %d\n", -actual);
74 			return;
75 		}
76 		remain -= actual;
77 	}
78 	return;
79 }
80 
81 int net_read(int fd, void *buf, int len)
82 {
83 	int n;
84 
85 	n = os_read_file(fd,  buf,  len);
86 
87 	if(n == -EAGAIN)
88 		return(0);
89 	else if(n == 0)
90 		return(-ENOTCONN);
91 	return(n);
92 }
93 
94 int net_recvfrom(int fd, void *buf, int len)
95 {
96 	int n;
97 
98 	while(((n = recvfrom(fd,  buf,  len, 0, NULL, NULL)) < 0) &&
99 	      (errno == EINTR)) ;
100 
101 	if(n < 0){
102 		if(errno == EAGAIN) return(0);
103 		return(-errno);
104 	}
105 	else if(n == 0) return(-ENOTCONN);
106 	return(n);
107 }
108 
109 int net_write(int fd, void *buf, int len)
110 {
111 	int n;
112 
113 	n = os_write_file(fd, buf, len);
114 
115 	if(n == -EAGAIN)
116 		return(0);
117 	else if(n == 0)
118 		return(-ENOTCONN);
119 	return(n);
120 }
121 
122 int net_send(int fd, void *buf, int len)
123 {
124 	int n;
125 
126 	while(((n = send(fd, buf, len, 0)) < 0) && (errno == EINTR)) ;
127 	if(n < 0){
128 		if(errno == EAGAIN) return(0);
129 		return(-errno);
130 	}
131 	else if(n == 0) return(-ENOTCONN);
132 	return(n);
133 }
134 
135 int net_sendto(int fd, void *buf, int len, void *to, int sock_len)
136 {
137 	int n;
138 
139 	while(((n = sendto(fd, buf, len, 0, (struct sockaddr *) to,
140 			   sock_len)) < 0) && (errno == EINTR)) ;
141 	if(n < 0){
142 		if(errno == EAGAIN) return(0);
143 		return(-errno);
144 	}
145 	else if(n == 0) return(-ENOTCONN);
146 	return(n);
147 }
148 
149 struct change_pre_exec_data {
150 	int close_me;
151 	int stdout;
152 };
153 
154 static void change_pre_exec(void *arg)
155 {
156 	struct change_pre_exec_data *data = arg;
157 
158 	os_close_file(data->close_me);
159 	dup2(data->stdout, 1);
160 }
161 
162 static int change_tramp(char **argv, char *output, int output_len)
163 {
164 	int pid, fds[2], err;
165 	struct change_pre_exec_data pe_data;
166 
167 	err = os_pipe(fds, 1, 0);
168 	if(err < 0){
169 		printk("change_tramp - pipe failed, err = %d\n", -err);
170 		return(err);
171 	}
172 	pe_data.close_me = fds[0];
173 	pe_data.stdout = fds[1];
174 	pid = run_helper(change_pre_exec, &pe_data, argv, NULL);
175 
176 	read_output(fds[0], output, output_len);
177 	os_close_file(fds[0]);
178 	os_close_file(fds[1]);
179 
180 	if (pid > 0)
181 		CATCH_EINTR(err = waitpid(pid, NULL, 0));
182 	return(pid);
183 }
184 
185 static void change(char *dev, char *what, unsigned char *addr,
186 		   unsigned char *netmask)
187 {
188 	char addr_buf[sizeof("255.255.255.255\0")];
189 	char netmask_buf[sizeof("255.255.255.255\0")];
190 	char version[sizeof("nnnnn\0")];
191 	char *argv[] = { "uml_net", version, what, dev, addr_buf,
192 			 netmask_buf, NULL };
193 	char *output;
194 	int output_len, pid;
195 
196 	sprintf(version, "%d", UML_NET_VERSION);
197 	sprintf(addr_buf, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
198 	sprintf(netmask_buf, "%d.%d.%d.%d", netmask[0], netmask[1],
199 		netmask[2], netmask[3]);
200 
201 	output_len = page_size();
202 	output = um_kmalloc(output_len);
203 	if(output == NULL)
204 		printk("change : failed to allocate output buffer\n");
205 
206 	pid = change_tramp(argv, output, output_len);
207 	if(pid < 0) return;
208 
209 	if(output != NULL){
210 		printk("%s", output);
211 		kfree(output);
212 	}
213 }
214 
215 void open_addr(unsigned char *addr, unsigned char *netmask, void *arg)
216 {
217 	change(arg, "add", addr, netmask);
218 }
219 
220 void close_addr(unsigned char *addr, unsigned char *netmask, void *arg)
221 {
222 	change(arg, "del", addr, netmask);
223 }
224 
225 char *split_if_spec(char *str, ...)
226 {
227 	char **arg, *end;
228 	va_list ap;
229 
230 	va_start(ap, str);
231 	while((arg = va_arg(ap, char **)) != NULL){
232 		if(*str == '\0')
233 			return(NULL);
234 		end = strchr(str, ',');
235 		if(end != str)
236 			*arg = str;
237 		if(end == NULL)
238 			return(NULL);
239 		*end++ = '\0';
240 		str = end;
241 	}
242 	va_end(ap);
243 	return(str);
244 }
245 
246 /*
247  * Overrides for Emacs so that we follow Linus's tabbing style.
248  * Emacs will notice this stuff at the end of the file and automatically
249  * adjust the settings for this buffer only.  This must remain at the end
250  * of the file.
251  * ---------------------------------------------------------------------------
252  * Local variables:
253  * c-file-style: "linux"
254  * End:
255  */
256