xref: /openbmc/linux/arch/um/drivers/net_user.c (revision 87c2ce3b)
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 "os.h"
20 
21 int tap_open_common(void *dev, char *gate_addr)
22 {
23 	int tap_addr[4];
24 
25 	if(gate_addr == NULL) return(0);
26 	if(sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
27 		  &tap_addr[1], &tap_addr[2], &tap_addr[3]) != 4){
28 		printk("Invalid tap IP address - '%s'\n", gate_addr);
29 		return(-EINVAL);
30 	}
31 	return(0);
32 }
33 
34 void tap_check_ips(char *gate_addr, unsigned char *eth_addr)
35 {
36 	int tap_addr[4];
37 
38 	if((gate_addr != NULL) &&
39 	   (sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
40 		   &tap_addr[1], &tap_addr[2], &tap_addr[3]) == 4) &&
41 	   (eth_addr[0] == tap_addr[0]) &&
42 	   (eth_addr[1] == tap_addr[1]) &&
43 	   (eth_addr[2] == tap_addr[2]) &&
44 	   (eth_addr[3] == tap_addr[3])){
45 		printk("The tap IP address and the UML eth IP address"
46 		       " must be different\n");
47 	}
48 }
49 
50 void read_output(int fd, char *output, int len)
51 {
52 	int remain, n, actual;
53 	char c;
54 
55 	if(output == NULL){
56 		output = &c;
57 		len = sizeof(c);
58 	}
59 
60 	*output = '\0';
61 	n = os_read_file(fd, &remain, sizeof(remain));
62 	if(n != sizeof(remain)){
63 		printk("read_output - read of length failed, err = %d\n", -n);
64 		return;
65 	}
66 
67 	while(remain != 0){
68 		n = (remain < len) ? remain : len;
69 		actual = os_read_file(fd, output, n);
70 		if(actual != n){
71 			printk("read_output - read of data failed, "
72 			       "err = %d\n", -actual);
73 			return;
74 		}
75 		remain -= actual;
76 	}
77 	return;
78 }
79 
80 int net_read(int fd, void *buf, int len)
81 {
82 	int n;
83 
84 	n = os_read_file(fd,  buf,  len);
85 
86 	if(n == -EAGAIN)
87 		return(0);
88 	else if(n == 0)
89 		return(-ENOTCONN);
90 	return(n);
91 }
92 
93 int net_recvfrom(int fd, void *buf, int len)
94 {
95 	int n;
96 
97 	while(((n = recvfrom(fd,  buf,  len, 0, NULL, NULL)) < 0) &&
98 	      (errno == EINTR)) ;
99 
100 	if(n < 0){
101 		if(errno == EAGAIN) return(0);
102 		return(-errno);
103 	}
104 	else if(n == 0) return(-ENOTCONN);
105 	return(n);
106 }
107 
108 int net_write(int fd, void *buf, int len)
109 {
110 	int n;
111 
112 	n = os_write_file(fd, buf, len);
113 
114 	if(n == -EAGAIN)
115 		return(0);
116 	else if(n == 0)
117 		return(-ENOTCONN);
118 	return(n);
119 }
120 
121 int net_send(int fd, void *buf, int len)
122 {
123 	int n;
124 
125 	while(((n = send(fd, buf, len, 0)) < 0) && (errno == EINTR)) ;
126 	if(n < 0){
127 		if(errno == EAGAIN) return(0);
128 		return(-errno);
129 	}
130 	else if(n == 0) return(-ENOTCONN);
131 	return(n);
132 }
133 
134 int net_sendto(int fd, void *buf, int len, void *to, int sock_len)
135 {
136 	int n;
137 
138 	while(((n = sendto(fd, buf, len, 0, (struct sockaddr *) to,
139 			   sock_len)) < 0) && (errno == EINTR)) ;
140 	if(n < 0){
141 		if(errno == EAGAIN) return(0);
142 		return(-errno);
143 	}
144 	else if(n == 0) return(-ENOTCONN);
145 	return(n);
146 }
147 
148 struct change_pre_exec_data {
149 	int close_me;
150 	int stdout;
151 };
152 
153 static void change_pre_exec(void *arg)
154 {
155 	struct change_pre_exec_data *data = arg;
156 
157 	os_close_file(data->close_me);
158 	dup2(data->stdout, 1);
159 }
160 
161 static int change_tramp(char **argv, char *output, int output_len)
162 {
163 	int pid, fds[2], err;
164 	struct change_pre_exec_data pe_data;
165 
166 	err = os_pipe(fds, 1, 0);
167 	if(err < 0){
168 		printk("change_tramp - pipe failed, err = %d\n", -err);
169 		return(err);
170 	}
171 	pe_data.close_me = fds[0];
172 	pe_data.stdout = fds[1];
173 	pid = run_helper(change_pre_exec, &pe_data, argv, NULL);
174 
175 	read_output(fds[0], output, output_len);
176 	os_close_file(fds[0]);
177 	os_close_file(fds[1]);
178 
179 	if (pid > 0)
180 		CATCH_EINTR(err = waitpid(pid, NULL, 0));
181 	return(pid);
182 }
183 
184 static void change(char *dev, char *what, unsigned char *addr,
185 		   unsigned char *netmask)
186 {
187 	char addr_buf[sizeof("255.255.255.255\0")];
188 	char netmask_buf[sizeof("255.255.255.255\0")];
189 	char version[sizeof("nnnnn\0")];
190 	char *argv[] = { "uml_net", version, what, dev, addr_buf,
191 			 netmask_buf, NULL };
192 	char *output;
193 	int output_len, pid;
194 
195 	sprintf(version, "%d", UML_NET_VERSION);
196 	sprintf(addr_buf, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
197 	sprintf(netmask_buf, "%d.%d.%d.%d", netmask[0], netmask[1],
198 		netmask[2], netmask[3]);
199 
200 	output_len = page_size();
201 	output = um_kmalloc(output_len);
202 	if(output == NULL)
203 		printk("change : failed to allocate output buffer\n");
204 
205 	pid = change_tramp(argv, output, output_len);
206 	if(pid < 0) return;
207 
208 	if(output != NULL){
209 		printk("%s", output);
210 		kfree(output);
211 	}
212 }
213 
214 void open_addr(unsigned char *addr, unsigned char *netmask, void *arg)
215 {
216 	change(arg, "add", addr, netmask);
217 }
218 
219 void close_addr(unsigned char *addr, unsigned char *netmask, void *arg)
220 {
221 	change(arg, "del", addr, netmask);
222 }
223 
224 char *split_if_spec(char *str, ...)
225 {
226 	char **arg, *end;
227 	va_list ap;
228 
229 	va_start(ap, str);
230 	while((arg = va_arg(ap, char **)) != NULL){
231 		if(*str == '\0')
232 			return(NULL);
233 		end = strchr(str, ',');
234 		if(end != str)
235 			*arg = str;
236 		if(end == NULL)
237 			return(NULL);
238 		*end++ = '\0';
239 		str = end;
240 	}
241 	va_end(ap);
242 	return(str);
243 }
244 
245 /*
246  * Overrides for Emacs so that we follow Linus's tabbing style.
247  * Emacs will notice this stuff at the end of the file and automatically
248  * adjust the settings for this buffer only.  This must remain at the end
249  * of the file.
250  * ---------------------------------------------------------------------------
251  * Local variables:
252  * c-file-style: "linux"
253  * End:
254  */
255