/* getroot.c - Get root device */ /* * PUPA -- Preliminary Universal Programming Architecture for GRUB * Copyright (C) 1999,2000,2001,2002 Free Software Foundation, Inc. * Copyright (C) 2002 Yoshinori K. Okuji * Copyright (C) 2003 Marco Gerards * * PUPA is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with PUPA; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include static void strip_extra_slashes (char *dir) { char *p = dir; while ((p = strchr (p, '/')) != 0) { if (p[1] == '/') { memmove (p, p + 1, strlen (p)); continue; } else if (p[1] == '\0') { p[0] = '\0'; break; } p++; } } static char * xgetcwd (void) { size_t size = 10; char *path; path = xmalloc (size); while (! getcwd (path, size)) { size <<= 1; path = xrealloc (path, size); } return path; } char * pupa_get_prefix (const char *dir) { char *saved_cwd; char *abs_dir, *prev_dir; char *prefix; struct stat st, prev_st; /* Save the current directory. */ saved_cwd = xgetcwd (); if (chdir (dir) < 0) pupa_util_error ("Cannot change directory to `%s'", dir); abs_dir = xgetcwd (); strip_extra_slashes (abs_dir); prev_dir = xstrdup (abs_dir); if (stat (".", &prev_st) < 0) pupa_util_error ("Cannot stat `%s'", dir); if (! S_ISDIR (prev_st.st_mode)) pupa_util_error ("`%s' is not a directory", dir); while (1) { if (chdir ("..") < 0) pupa_util_error ("Cannot change directory to the parent"); if (stat (".", &st) < 0) pupa_util_error ("Cannot stat current directory"); if (! S_ISDIR (st.st_mode)) pupa_util_error ("Current directory is not a directory???"); if (prev_st.st_dev != st.st_dev || prev_st.st_ino == st.st_ino) break; free (prev_dir); prev_dir = xgetcwd (); prev_st = st; } strip_extra_slashes (prev_dir); prefix = xmalloc (strlen (abs_dir) - strlen (prev_dir) + 2); prefix[0] = '/'; strcpy (prefix + 1, abs_dir + strlen (prev_dir)); strip_extra_slashes (prefix); if (chdir (saved_cwd) < 0) pupa_util_error ("Cannot change directory to `%s'", dir); free (saved_cwd); free (abs_dir); free (prev_dir); pupa_util_info ("prefix = %s", prefix); return prefix; } static char * find_root_device (const char *dir, dev_t dev) { DIR *dp; char *saved_cwd; struct dirent *ent; dp = opendir (dir); if (! dp) return 0; saved_cwd = xgetcwd (); pupa_util_info ("changing current directory to %s", dir); if (chdir (dir) < 0) { free (saved_cwd); closedir (dp); return 0; } while ((ent = readdir (dp)) != 0) { struct stat st; if (strcmp (ent->d_name, ".") == 0 || strcmp (ent->d_name, "..") == 0) continue; if (lstat (ent->d_name, &st) < 0) /* Ignore any error. */ continue; if (S_ISLNK (st.st_mode)) /* Don't follow symbolic links. */ continue; if (S_ISDIR (st.st_mode)) { /* Find it recursively. */ char *res; res = find_root_device (ent->d_name, dev); if (res) { if (chdir (saved_cwd) < 0) pupa_util_error ("Cannot restore the original directory"); free (saved_cwd); closedir (dp); return res; } } if (S_ISBLK (st.st_mode) && st.st_rdev == dev) { /* Found! */ char *res; char *cwd; cwd = xgetcwd (); res = xmalloc (strlen (cwd) + strlen (ent->d_name) + 2); sprintf (res, "%s/%s", cwd, ent->d_name); strip_extra_slashes (res); free (cwd); if (chdir (saved_cwd) < 0) pupa_util_error ("Cannot restore the original directory"); free (saved_cwd); closedir (dp); return res; } } if (chdir (saved_cwd) < 0) pupa_util_error ("Cannot restore the original directory"); free (saved_cwd); closedir (dp); return 0; } char * pupa_guess_root_device (const char *dir) { struct stat st; char *os_dev; if (stat (dir, &st) < 0) pupa_util_error ("Cannot stat `%s'", dir); /* This might be truly slow, but is there any better way? */ os_dev = find_root_device ("/dev", st.st_dev); if (! os_dev) return 0; return pupa_util_biosdisk_get_pupa_dev (os_dev); }