1/* vi: set sw=4 ts=4: */ 2/* 3 * Utility routines. 4 * 5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> 6 * 7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. 8 */ 9 10#include "libbb.h" 11 12 13/* Do not reallocate all this stuff on each recursion */ 14enum { DEVNAME_MAX = 256 }; 15struct arena { 16 struct stat st; 17 dev_t dev; 18 /* Was PATH_MAX, but we recurse _/dev_. We can assume 19 * people are not crazy enough to have mega-deep tree there */ 20 char devpath[DEVNAME_MAX]; 21}; 22 23static char *find_block_device_in_dir(struct arena *ap) 24{ 25 DIR *dir; 26 struct dirent *entry; 27 char *retpath = NULL; 28 int len, rem; 29 30 dir = opendir(ap->devpath); 31 if (!dir) 32 return NULL; 33 34 len = strlen(ap->devpath); 35 rem = DEVNAME_MAX-2 - len; 36 if (rem <= 0) 37 return NULL; 38 ap->devpath[len++] = '/'; 39 40 while ((entry = readdir(dir)) != NULL) { 41 safe_strncpy(ap->devpath + len, entry->d_name, rem); 42 /* lstat: do not follow links */ 43 if (lstat(ap->devpath, &ap->st) != 0) 44 continue; 45 if (S_ISBLK(ap->st.st_mode) && ap->st.st_rdev == ap->dev) { 46 retpath = xstrdup(ap->devpath); 47 break; 48 } 49 if (S_ISDIR(ap->st.st_mode)) { 50 /* Do not recurse for '.' and '..' */ 51 if (DOT_OR_DOTDOT(entry->d_name)) 52 continue; 53 retpath = find_block_device_in_dir(ap); 54 if (retpath) 55 break; 56 } 57 } 58 closedir(dir); 59 60 return retpath; 61} 62 63char *find_block_device(const char *path) 64{ 65 struct arena a; 66 67 if (stat(path, &a.st) != 0) 68 return NULL; 69 a.dev = S_ISBLK(a.st.st_mode) ? a.st.st_rdev : a.st.st_dev; 70 strcpy(a.devpath, "/dev"); 71 return find_block_device_in_dir(&a); 72} 73