1 /* 2 * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com) 3 * Licensed under the GPL 4 */ 5 6 #include <stdio.h> 7 #include <unistd.h> 8 #include <errno.h> 9 #include <string.h> 10 #include <stdlib.h> 11 #include <dirent.h> 12 #include <signal.h> 13 #include <sys/stat.h> 14 #include <sys/param.h> 15 #include "user.h" 16 #include "umid.h" 17 #include "init.h" 18 #include "os.h" 19 #include "user_util.h" 20 #include "choose-mode.h" 21 22 #define UMID_LEN 64 23 #define UML_DIR "~/.uml/" 24 25 /* Changed by set_umid and make_umid, which are run early in boot */ 26 static char umid[UMID_LEN] = { 0 }; 27 28 /* Changed by set_uml_dir and make_uml_dir, which are run early in boot */ 29 static char *uml_dir = UML_DIR; 30 31 /* Changed by set_umid */ 32 static int umid_is_random = 1; 33 static int umid_inited = 0; 34 35 static int make_umid(int (*printer)(const char *fmt, ...)); 36 37 static int __init set_umid(char *name, int is_random, 38 int (*printer)(const char *fmt, ...)) 39 { 40 if(umid_inited){ 41 (*printer)("Unique machine name can't be set twice\n"); 42 return(-1); 43 } 44 45 if(strlen(name) > UMID_LEN - 1) 46 (*printer)("Unique machine name is being truncated to %d " 47 "characters\n", UMID_LEN); 48 strlcpy(umid, name, sizeof(umid)); 49 50 umid_is_random = is_random; 51 umid_inited = 1; 52 return 0; 53 } 54 55 static int __init set_umid_arg(char *name, int *add) 56 { 57 *add = 0; 58 return(set_umid(name, 0, printf)); 59 } 60 61 __uml_setup("umid=", set_umid_arg, 62 "umid=<name>\n" 63 " This is used to assign a unique identity to this UML machine and\n" 64 " is used for naming the pid file and management console socket.\n\n" 65 ); 66 67 int __init umid_file_name(char *name, char *buf, int len) 68 { 69 int n; 70 71 if(!umid_inited && make_umid(printk)) return(-1); 72 73 n = strlen(uml_dir) + strlen(umid) + strlen(name) + 1; 74 if(n > len){ 75 printk("umid_file_name : buffer too short\n"); 76 return(-1); 77 } 78 79 sprintf(buf, "%s%s/%s", uml_dir, umid, name); 80 return(0); 81 } 82 83 extern int tracing_pid; 84 85 static int __init create_pid_file(void) 86 { 87 char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; 88 char pid[sizeof("nnnnn\0")]; 89 int fd, n; 90 91 if(umid_file_name("pid", file, sizeof(file))) return 0; 92 93 fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))), 94 0644); 95 if(fd < 0){ 96 printf("Open of machine pid file \"%s\" failed: %s\n", 97 file, strerror(-fd)); 98 return 0; 99 } 100 101 sprintf(pid, "%d\n", os_getpid()); 102 n = os_write_file(fd, pid, strlen(pid)); 103 if(n != strlen(pid)) 104 printf("Write of pid file failed - err = %d\n", -n); 105 os_close_file(fd); 106 return 0; 107 } 108 109 static int actually_do_remove(char *dir) 110 { 111 DIR *directory; 112 struct dirent *ent; 113 int len; 114 char file[256]; 115 116 directory = opendir(dir); 117 if(directory == NULL){ 118 printk("actually_do_remove : couldn't open directory '%s', " 119 "errno = %d\n", dir, errno); 120 return(1); 121 } 122 while((ent = readdir(directory)) != NULL){ 123 if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, "..")) 124 continue; 125 len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1; 126 if(len > sizeof(file)){ 127 printk("Not deleting '%s' from '%s' - name too long\n", 128 ent->d_name, dir); 129 continue; 130 } 131 sprintf(file, "%s/%s", dir, ent->d_name); 132 if(unlink(file) < 0){ 133 printk("actually_do_remove : couldn't remove '%s' " 134 "from '%s', errno = %d\n", ent->d_name, dir, 135 errno); 136 return(1); 137 } 138 } 139 if(rmdir(dir) < 0){ 140 printk("actually_do_remove : couldn't rmdir '%s', " 141 "errno = %d\n", dir, errno); 142 return(1); 143 } 144 return(0); 145 } 146 147 void remove_umid_dir(void) 148 { 149 char dir[strlen(uml_dir) + UMID_LEN + 1]; 150 if(!umid_inited) return; 151 152 sprintf(dir, "%s%s", uml_dir, umid); 153 actually_do_remove(dir); 154 } 155 156 char *get_umid(int only_if_set) 157 { 158 if(only_if_set && umid_is_random) return(NULL); 159 return(umid); 160 } 161 162 int not_dead_yet(char *dir) 163 { 164 char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; 165 char pid[sizeof("nnnnn\0")], *end; 166 int dead, fd, p, n; 167 168 sprintf(file, "%s/pid", dir); 169 dead = 0; 170 fd = os_open_file(file, of_read(OPENFLAGS()), 0); 171 if(fd < 0){ 172 if(fd != -ENOENT){ 173 printk("not_dead_yet : couldn't open pid file '%s', " 174 "err = %d\n", file, -fd); 175 return(1); 176 } 177 dead = 1; 178 } 179 if(fd > 0){ 180 n = os_read_file(fd, pid, sizeof(pid)); 181 if(n < 0){ 182 printk("not_dead_yet : couldn't read pid file '%s', " 183 "err = %d\n", file, -n); 184 return(1); 185 } 186 p = strtoul(pid, &end, 0); 187 if(end == pid){ 188 printk("not_dead_yet : couldn't parse pid file '%s', " 189 "errno = %d\n", file, errno); 190 dead = 1; 191 } 192 if(((kill(p, 0) < 0) && (errno == ESRCH)) || 193 (p == CHOOSE_MODE(tracing_pid, os_getpid()))) 194 dead = 1; 195 } 196 if(!dead) return(1); 197 return(actually_do_remove(dir)); 198 } 199 200 static int __init set_uml_dir(char *name, int *add) 201 { 202 if((strlen(name) > 0) && (name[strlen(name) - 1] != '/')){ 203 uml_dir = malloc(strlen(name) + 2); 204 if(uml_dir == NULL){ 205 printf("Failed to malloc uml_dir - error = %d\n", 206 errno); 207 uml_dir = name; 208 /* Return 0 here because do_initcalls doesn't look at 209 * the return value. 210 */ 211 return(0); 212 } 213 sprintf(uml_dir, "%s/", name); 214 } 215 else uml_dir = name; 216 return(0); 217 } 218 219 static int __init make_uml_dir(void) 220 { 221 char dir[MAXPATHLEN + 1] = { '\0' }; 222 int len; 223 224 if(*uml_dir == '~'){ 225 char *home = getenv("HOME"); 226 227 if(home == NULL){ 228 printf("make_uml_dir : no value in environment for " 229 "$HOME\n"); 230 exit(1); 231 } 232 strlcpy(dir, home, sizeof(dir)); 233 uml_dir++; 234 } 235 len = strlen(dir); 236 strncat(dir, uml_dir, sizeof(dir) - len); 237 len = strlen(dir); 238 if((len > 0) && (len < sizeof(dir) - 1) && (dir[len - 1] != '/')){ 239 dir[len] = '/'; 240 dir[len + 1] = '\0'; 241 } 242 243 uml_dir = malloc(strlen(dir) + 1); 244 if(uml_dir == NULL){ 245 printf("make_uml_dir : malloc failed, errno = %d\n", errno); 246 exit(1); 247 } 248 strcpy(uml_dir, dir); 249 250 if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){ 251 printf("Failed to mkdir %s: %s\n", uml_dir, strerror(errno)); 252 return(-1); 253 } 254 return 0; 255 } 256 257 static int __init make_umid(int (*printer)(const char *fmt, ...)) 258 { 259 int fd, err; 260 char tmp[strlen(uml_dir) + UMID_LEN + 1]; 261 262 strlcpy(tmp, uml_dir, sizeof(tmp)); 263 264 if(!umid_inited){ 265 strcat(tmp, "XXXXXX"); 266 fd = mkstemp(tmp); 267 if(fd < 0){ 268 (*printer)("make_umid - mkstemp(%s) failed: %s\n", 269 tmp,strerror(errno)); 270 return(1); 271 } 272 273 os_close_file(fd); 274 /* There's a nice tiny little race between this unlink and 275 * the mkdir below. It'd be nice if there were a mkstemp 276 * for directories. 277 */ 278 unlink(tmp); 279 set_umid(&tmp[strlen(uml_dir)], 1, printer); 280 } 281 282 sprintf(tmp, "%s%s", uml_dir, umid); 283 284 err = mkdir(tmp, 0777); 285 if(err < 0){ 286 if(errno == EEXIST){ 287 if(not_dead_yet(tmp)){ 288 (*printer)("umid '%s' is in use\n", umid); 289 return(-1); 290 } 291 err = mkdir(tmp, 0777); 292 } 293 } 294 if(err < 0){ 295 (*printer)("Failed to create %s - errno = %d\n", umid, errno); 296 return(-1); 297 } 298 299 return(0); 300 } 301 302 __uml_setup("uml_dir=", set_uml_dir, 303 "uml_dir=<directory>\n" 304 " The location to place the pid and umid files.\n\n" 305 ); 306 307 static int __init make_umid_setup(void) 308 { 309 /* one function with the ordering we need ... */ 310 make_uml_dir(); 311 make_umid(printf); 312 return create_pid_file(); 313 } 314 __uml_postsetup(make_umid_setup); 315 316 /* 317 * Overrides for Emacs so that we follow Linus's tabbing style. 318 * Emacs will notice this stuff at the end of the file and automatically 319 * adjust the settings for this buffer only. This must remain at the end 320 * of the file. 321 * --------------------------------------------------------------------------- 322 * Local variables: 323 * c-file-style: "linux" 324 * End: 325 */ 326