arch/um/drivers/net_user.c

   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 <sys/time.h>
  16 #include "user.h"
  17 #include "kern_util.h"
  18 #include "net_user.h"
  19 #include "os.h"
  20 #include "um_malloc.h"
  21 #include "kern_constants.h"
  22
  23 int tap_open_common(void *dev, char *gate_addr)
  24 {
  25         int tap_addr[4];
  26
  27         if(gate_addr == NULL)
  28                 return 0;
  29         if(sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
  30                   &tap_addr[1], &tap_addr[2], &tap_addr[3]) != 4){
  31                 printk("Invalid tap IP address - '%s'\n", gate_addr);
  32                 return -EINVAL;
  33         }
  34         return 0;
  35 }
  36
  37 void tap_check_ips(char *gate_addr, unsigned char *eth_addr)
  38 {
  39         int tap_addr[4];
  40
  41         if((gate_addr != NULL) &&
  42            (sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
  43                    &tap_addr[1], &tap_addr[2], &tap_addr[3]) == 4) &&
  44            (eth_addr[0] == tap_addr[0]) &&
  45            (eth_addr[1] == tap_addr[1]) &&
  46            (eth_addr[2] == tap_addr[2]) &&
  47            (eth_addr[3] == tap_addr[3])){
  48                 printk("The tap IP address and the UML eth IP address"
  49                        " must be different\n");
  50         }
  51 }
  52
  53 /* Do reliable error handling as this fails frequently enough. */
  54 void read_output(int fd, char *output, int len)
  55 {
  56         int remain, ret, expected;
  57         char c;
  58         char *str;
  59
  60         if(output == NULL){
  61                 output = &c;
  62                 len = sizeof(c);
  63         }
  64
  65         *output = '\0';
  66         ret = os_read_file(fd, &remain, sizeof(remain));
  67
  68         if (ret != sizeof(remain)) {
  69                 expected = sizeof(remain);
  70                 str = "length";
  71                 goto err;
  72         }
  73
  74         while(remain != 0){
  75                 expected = (remain < len) ? remain : len;
  76                 ret = os_read_file(fd, output, expected);
  77                 if (ret != expected) {
  78                         str = "data";
  79                         goto err;
  80                 }
  81                 remain -= ret;
  82         }
  83
  84         return;
  85
  86 err:
  87         if (ret < 0)
  88                 printk("read_output - read of %s failed, errno = %d\n", str, -ret);
  89         else
  90                 printk("read_output - read of %s failed, read only %d of %d bytes\n", str, ret, expected);
  91 }
  92
  93 int net_read(int fd, void *buf, int len)
  94 {
  95         int n;
  96
  97         n = os_read_file(fd,  buf,  len);
  98
  99         if(n == -EAGAIN)
 100                 return 0;
 101         else if(n == 0)
 102                 return -ENOTCONN;
 103         return n;
 104 }
 105
 106 int net_recvfrom(int fd, void *buf, int len)
 107 {
 108         int n;
 109
 110         CATCH_EINTR(n = recvfrom(fd,  buf,  len, 0, NULL, NULL));
 111         if(n < 0){
 112                 if(errno == EAGAIN)
 113                         return 0;
 114                 return -errno;
 115         }
 116         else if(n == 0)
 117                 return -ENOTCONN;
 118         return n;
 119 }
 120
 121 int net_write(int fd, void *buf, int len)
 122 {
 123         int n;
 124
 125         n = os_write_file(fd, buf, len);
 126
 127         if(n == -EAGAIN)
 128                 return 0;
 129         else if(n == 0)
 130                 return -ENOTCONN;
 131         return n;
 132 }
 133
 134 int net_send(int fd, void *buf, int len)
 135 {
 136         int n;
 137
 138         CATCH_EINTR(n = send(fd, buf, len, 0));
 139         if(n < 0){
 140                 if(errno == EAGAIN)
 141                         return 0;
 142                 return -errno;
 143         }
 144         else if(n == 0)
 145                 return -ENOTCONN;
 146         return n;
 147 }
 148
 149 int net_sendto(int fd, void *buf, int len, void *to, int sock_len)
 150 {
 151         int n;
 152
 153         CATCH_EINTR(n = sendto(fd, buf, len, 0, (struct sockaddr *) to,
 154                                sock_len));
 155         if(n < 0){
 156                 if(errno == EAGAIN)
 157                         return 0;
 158                 return -errno;
 159         }
 160         else if(n == 0)
 161                 return -ENOTCONN;
 162         return n;
 163 }
 164
 165 struct change_pre_exec_data {
 166         int close_me;
 167         int stdout;
 168 };
 169
 170 static void change_pre_exec(void *arg)
 171 {
 172         struct change_pre_exec_data *data = arg;
 173
 174         os_close_file(data->close_me);
 175         dup2(data->stdout, 1);
 176 }
 177
 178 static int change_tramp(char **argv, char *output, int output_len)
 179 {
 180         int pid, fds[2], err;
 181         struct change_pre_exec_data pe_data;
 182
 183         err = os_pipe(fds, 1, 0);
 184         if(err < 0){
 185                 printk("change_tramp - pipe failed, err = %d\n", -err);
 186                 return err;
 187         }
 188         pe_data.close_me = fds[0];
 189         pe_data.stdout = fds[1];
 190         pid = run_helper(change_pre_exec, &pe_data, argv, NULL);
 191
 192         if (pid > 0)    /* Avoid hang as we won't get data in failure case. */
 193                 read_output(fds[0], output, output_len);
 194
 195         os_close_file(fds[0]);
 196         os_close_file(fds[1]);
 197
 198         if (pid > 0)
 199                 CATCH_EINTR(err = waitpid(pid, NULL, 0));
 200         return pid;
 201 }
 202
 203 static void change(char *dev, char *what, unsigned char *addr,
 204                    unsigned char *netmask)
 205 {
 206         char addr_buf[sizeof("255.255.255.255\0")];
 207         char netmask_buf[sizeof("255.255.255.255\0")];
 208         char version[sizeof("nnnnn\0")];
 209         char *argv[] = { "uml_net", version, what, dev, addr_buf,
 210                          netmask_buf, NULL };
 211         char *output;
 212         int output_len, pid;
 213
 214         sprintf(version, "%d", UML_NET_VERSION);
 215         sprintf(addr_buf, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
 216         sprintf(netmask_buf, "%d.%d.%d.%d", netmask[0], netmask[1],
 217                 netmask[2], netmask[3]);
 218
 219         output_len = UM_KERN_PAGE_SIZE;
 220         output = um_kmalloc(output_len);
 221         if(output == NULL)
 222                 printk("change : failed to allocate output buffer\n");
 223
 224         pid = change_tramp(argv, output, output_len);
 225         if(pid < 0) return;
 226
 227         if(output != NULL){
 228                 printk("%s", output);
 229                 kfree(output);
 230         }
 231 }
 232
 233 void open_addr(unsigned char *addr, unsigned char *netmask, void *arg)
 234 {
 235         change(arg, "add", addr, netmask);
 236 }
 237
 238 void close_addr(unsigned char *addr, unsigned char *netmask, void *arg)
 239 {
 240         change(arg, "del", addr, netmask);
 241 }
 242
 243 char *split_if_spec(char *str, ...)
 244 {
 245         char **arg, *end;
 246         va_list ap;
 247
 248         va_start(ap, str);
 249         while((arg = va_arg(ap, char **)) != NULL){
 250                 if(*str == '\0')
 251                         return NULL;
 252                 end = strchr(str, ',');
 253                 if(end != str)
 254                         *arg = str;
 255                 if(end == NULL)
 256                         return NULL;
 257                 *end++ = '\0';
 258                 str = end;
 259         }
 260         va_end(ap);
 261         return str;
 262 }