1 /* 2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include <stdio.h> 7 #include <unistd.h> 8 #include <stdarg.h> 9 #include <errno.h> 10 #include <stddef.h> 11 #include <string.h> 12 #include <sys/socket.h> 13 #include <sys/wait.h> 14 #include "net_user.h" 15 #include "kern_constants.h" 16 #include "os.h" 17 #include "um_malloc.h" 18 #include "user.h" 19 20 int tap_open_common(void *dev, char *gate_addr) 21 { 22 int tap_addr[4]; 23 24 if (gate_addr == NULL) 25 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(UM_KERN_ERR "Invalid tap IP address - '%s'\n", 29 gate_addr); 30 return -EINVAL; 31 } 32 return 0; 33 } 34 35 void tap_check_ips(char *gate_addr, unsigned 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(UM_KERN_ERR "The tap IP address and the UML eth IP " 47 "address must be different\n"); 48 } 49 } 50 51 /* Do reliable error handling as this fails frequently enough. */ 52 void read_output(int fd, char *output, int len) 53 { 54 int remain, ret, expected; 55 char c; 56 char *str; 57 58 if (output == NULL) { 59 output = &c; 60 len = sizeof(c); 61 } 62 63 *output = '\0'; 64 ret = read(fd, &remain, sizeof(remain)); 65 66 if (ret != sizeof(remain)) { 67 if (ret < 0) 68 ret = -errno; 69 expected = sizeof(remain); 70 str = "length"; 71 goto err; 72 } 73 74 while (remain != 0) { 75 expected = (remain < len) ? remain : len; 76 ret = read(fd, output, expected); 77 if (ret != expected) { 78 if (ret < 0) 79 ret = -errno; 80 str = "data"; 81 goto err; 82 } 83 remain -= ret; 84 } 85 86 return; 87 88 err: 89 if (ret < 0) 90 printk(UM_KERN_ERR "read_output - read of %s failed, " 91 "errno = %d\n", str, -ret); 92 else 93 printk(UM_KERN_ERR "read_output - read of %s failed, read only " 94 "%d of %d bytes\n", str, ret, expected); 95 } 96 97 int net_read(int fd, void *buf, int len) 98 { 99 int n; 100 101 n = read(fd, buf, len); 102 103 if ((n < 0) && (errno == EAGAIN)) 104 return 0; 105 else if (n == 0) 106 return -ENOTCONN; 107 return n; 108 } 109 110 int net_recvfrom(int fd, void *buf, int len) 111 { 112 int n; 113 114 CATCH_EINTR(n = recvfrom(fd, buf, len, 0, NULL, NULL)); 115 if (n < 0) { 116 if (errno == EAGAIN) 117 return 0; 118 return -errno; 119 } 120 else if (n == 0) 121 return -ENOTCONN; 122 return n; 123 } 124 125 int net_write(int fd, void *buf, int len) 126 { 127 int n; 128 129 n = write(fd, buf, len); 130 131 if ((n < 0) && (errno == EAGAIN)) 132 return 0; 133 else if (n == 0) 134 return -ENOTCONN; 135 return n; 136 } 137 138 int net_send(int fd, void *buf, int len) 139 { 140 int n; 141 142 CATCH_EINTR(n = send(fd, buf, len, 0)); 143 if (n < 0) { 144 if (errno == EAGAIN) 145 return 0; 146 return -errno; 147 } 148 else if (n == 0) 149 return -ENOTCONN; 150 return n; 151 } 152 153 int net_sendto(int fd, void *buf, int len, void *to, int sock_len) 154 { 155 int n; 156 157 CATCH_EINTR(n = sendto(fd, buf, len, 0, (struct sockaddr *) to, 158 sock_len)); 159 if (n < 0) { 160 if (errno == EAGAIN) 161 return 0; 162 return -errno; 163 } 164 else if (n == 0) 165 return -ENOTCONN; 166 return n; 167 } 168 169 struct change_pre_exec_data { 170 int close_me; 171 int stdout; 172 }; 173 174 static void change_pre_exec(void *arg) 175 { 176 struct change_pre_exec_data *data = arg; 177 178 close(data->close_me); 179 dup2(data->stdout, 1); 180 } 181 182 static int change_tramp(char **argv, char *output, int output_len) 183 { 184 int pid, fds[2], err; 185 struct change_pre_exec_data pe_data; 186 187 err = os_pipe(fds, 1, 0); 188 if (err < 0) { 189 printk(UM_KERN_ERR "change_tramp - pipe failed, err = %d\n", 190 -err); 191 return err; 192 } 193 pe_data.close_me = fds[0]; 194 pe_data.stdout = fds[1]; 195 pid = run_helper(change_pre_exec, &pe_data, argv); 196 197 if (pid > 0) /* Avoid hang as we won't get data in failure case. */ 198 read_output(fds[0], output, output_len); 199 200 close(fds[0]); 201 close(fds[1]); 202 203 if (pid > 0) 204 helper_wait(pid); 205 return pid; 206 } 207 208 static void change(char *dev, char *what, unsigned char *addr, 209 unsigned char *netmask) 210 { 211 char addr_buf[sizeof("255.255.255.255\0")]; 212 char netmask_buf[sizeof("255.255.255.255\0")]; 213 char version[sizeof("nnnnn\0")]; 214 char *argv[] = { "uml_net", version, what, dev, addr_buf, 215 netmask_buf, NULL }; 216 char *output; 217 int output_len, pid; 218 219 sprintf(version, "%d", UML_NET_VERSION); 220 sprintf(addr_buf, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]); 221 sprintf(netmask_buf, "%d.%d.%d.%d", netmask[0], netmask[1], 222 netmask[2], netmask[3]); 223 224 output_len = UM_KERN_PAGE_SIZE; 225 output = uml_kmalloc(output_len, UM_GFP_KERNEL); 226 if (output == NULL) 227 printk(UM_KERN_ERR "change : failed to allocate output " 228 "buffer\n"); 229 230 pid = change_tramp(argv, output, output_len); 231 if (pid < 0) return; 232 233 if (output != NULL) { 234 printk("%s", output); 235 kfree(output); 236 } 237 } 238 239 void open_addr(unsigned char *addr, unsigned char *netmask, void *arg) 240 { 241 change(arg, "add", addr, netmask); 242 } 243 244 void close_addr(unsigned char *addr, unsigned char *netmask, void *arg) 245 { 246 change(arg, "del", addr, netmask); 247 } 248 249 char *split_if_spec(char *str, ...) 250 { 251 char **arg, *end; 252 va_list ap; 253 254 va_start(ap, str); 255 while ((arg = va_arg(ap, char **)) != NULL) { 256 if (*str == '\0') 257 return NULL; 258 end = strchr(str, ','); 259 if (end != str) 260 *arg = str; 261 if (end == NULL) 262 return NULL; 263 *end++ = '\0'; 264 str = end; 265 } 266 va_end(ap); 267 return str; 268 } 269