ali@416: /*
ali@444:  * Copyright (C) 2012, 2014  J. Ali Harlow <ali@juiblex.co.uk>
ali@416:  *
ali@416:  * This program is free software; you can redistribute it and/or modify
ali@416:  * it under the terms of the GNU General Public License as published by
ali@416:  * the Free Software Foundation; either version 2 of the License, or
ali@416:  * (at your option) any later version.
ali@416:  *
ali@416:  * This program is distributed in the hope that it will be useful,
ali@416:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
ali@416:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
ali@416:  * GNU General Public License for more details.
ali@416:  *
ali@416:  * You should have received a copy of the GNU General Public License along
ali@416:  * with this program; if not, write to the Free Software Foundation, Inc.,
ali@416:  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
ali@416:  */
ali@416: 
ali@416: #include "config.h"
ali@416: 
ali@416: #if ENABLE_ATOMIC && !HAVE_WINDOWS_KTM
ali@416: 
ali@416: #include <stdlib.h>
ali@423: #include <stdio.h>
ali@416: #include <string.h>
ali@416: #include <unistd.h>
ali@416: #include <sys/types.h>
ali@416: #include <sys/stat.h>
ali@416: #include <fcntl.h>
ali@416: #include <dirent.h>
ali@416: #include <errno.h>
ali@444: #include <unistd.h>
ali@416: #include "razor-internal.h"
ali@416: 
ali@416: /*
ali@416:  * Emulated atomic support
ali@416:  *
ali@416:  * This implementation is better than nothing, but is certainly not atomic.
ali@416:  * It does have a couple of advantages over atomic-none:
ali@416:  *	- If a file operation fails while a package is being installed we
ali@416:  *	  have a good chance of being able to rollback the transaction to
ali@416:  *	  a well-known state.
ali@416:  *	- We behave similarly to atomic-ktm in that changes are not visible
ali@416:  *	  on disk to non-atomic operations (eg., scripts) until the atomic
ali@416:  *	  is committed. This makes the testsuite more likely to pick up
ali@416:  *	  problems that would otherwise only be found when using razor on
ali@416:  *	  an MS-Windows system which supports KTM.
ali@416:  */
ali@416: 
ali@416: #ifndef O_BINARY
ali@416: #define O_BINARY	0
ali@416: #endif
ali@416: 
ali@416: static void recursive_remove(const char *directory)
ali@416: {
ali@416: 	DIR *dp;
ali@416: 	struct dirent *dirp;
ali@416: 	char *buf;
ali@416: 
ali@416: 	dp = opendir(directory);
ali@416: 	while((dirp = readdir(dp))) {
ali@416: 		if (strcmp(dirp->d_name, ".") && strcmp(dirp->d_name, "..")) {
ali@416: 			buf = malloc(strlen(directory) + strlen(dirp->d_name)
ali@416: 				     + 2);
ali@416: 			sprintf(buf, "%s/%s", directory, dirp->d_name);
ali@416: 			if (remove(buf) < 0)
ali@416: 				recursive_remove(buf);
ali@416: 			free(buf);
ali@416: 		}
ali@416: 	}
ali@416: 
ali@416: 	rmdir(directory);
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT struct razor_atomic *razor_atomic_open(const char *description)
ali@416: {
ali@416: 	struct razor_atomic *atomic;
ali@416: 
ali@416: 	atomic = zalloc(sizeof *atomic);
ali@416: 
ali@416: 	atomic->description = strdup(description);
ali@416: 
ali@416: 	return atomic;
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT int razor_atomic_commit(struct razor_atomic *atomic)
ali@416: {
ali@416: 	struct atomic_action *actions;
ali@416: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: 	if (atomic->actions) {
ali@416: 		actions = atomic_action_list_reverse(atomic->actions);
ali@416: 		atomic->actions = NULL;
ali@416: 		actions = atomic_action_do(atomic, actions);
ali@416: 		atomic_action_free(actions);
ali@416: 	}
ali@416: 
ali@416: 	if (atomic->toplevel) {
ali@416: 		recursive_remove(atomic->toplevel);
ali@416: 		free(atomic->toplevel);
ali@416: 		atomic->toplevel = NULL;
ali@416: 	}
ali@416: 
ali@423: 	return razor_atomic_in_error_state(atomic);
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT void razor_atomic_destroy(struct razor_atomic *atomic)
ali@416: {
ali@416: 	if (atomic->toplevel) {
ali@416: 		recursive_remove(atomic->toplevel);
ali@416: 		free(atomic->toplevel);
ali@416: 		atomic->toplevel = NULL;
ali@416: 	}
ali@416: 
ali@423: 	if (atomic->error)
ali@423: 		razor_error_free(atomic->error);
ali@423: 
ali@416: 	free(atomic);
ali@416: }
ali@416: 
ali@444: #ifndef MSWIN_API
ali@444: static char *absolute_path(const char *path)
ali@444: {
ali@444: 	int len;
ali@444: 	char *result, *subpath, *p, *s, *t;
ali@444: 
ali@444: 	result = realpath(path, NULL);
ali@444: 
ali@444: 	if (!result && errno == ENOENT) {
ali@444: 		p = strdup(path);
ali@444: 		s = strrchr(p, '/');
ali@444: 
ali@444: 		while (s) {
ali@444: 			if (s == p) {
ali@444: 				result = strdup("/");
ali@444: 				break;
ali@444: 			}
ali@444: 
ali@444: 			*s = '\0';
ali@444: 			subpath = realpath(p, NULL);
ali@444: 
ali@444: 			if (subpath) {
ali@444: 				*s = '/';
ali@444: 				len = strlen(subpath);
ali@444: 				result = malloc(len + strlen(s) + 1);
ali@444: 				memcpy(result, subpath, len);
ali@444: 				strcpy(result + len, s);
ali@444: 				break;
ali@444: 			} else if (errno != ENOENT)
ali@444: 				break;
ali@444: 
ali@444: 			t = strrchr(p, '/');
ali@444: 			*s = '/';
ali@444: 			s = t;
ali@444: 		}
ali@444: 
ali@444: 		if (!s)
ali@444: 			result = realpath(".", NULL);
ali@444: 
ali@444: 		free(p);
ali@444: 	}
ali@444: 
ali@444: 	return result;
ali@444: }
ali@444: #endif
ali@444: 
ali@435: /*
ali@435:  * We need a toplevel directory in which to hold temporary files
ali@435:  * before they are committed. Since we can generally assume that
ali@444:  * we have write permissions anywhere on the filesystem in
ali@444:  * question, the best location is at the relevant mount point.
ali@444:  * The most common case where this assumption fails is when
ali@444:  * testing, when the current directory is a good choice.
ali@435:  */
ali@435: 
ali@435: static int
ali@435: razor_atomic_set_toplevel_from_path(struct razor_atomic *atomic,
ali@435: 				    const char *path)
ali@435: {
ali@444: #ifndef MSWIN_API
ali@444: 	dev_t filesystem;
ali@444: 	struct stat buf;
ali@444: #endif
ali@444: 
ali@435: 	if (razor_atomic_in_error_state(atomic))
ali@435: 		return -1;
ali@435: 
ali@435: 	if (atomic->toplevel)
ali@435: 		return 0;
ali@435: 
ali@435: #ifdef MSWIN_API
ali@435: 	if (path[0]=='\\' && path[1]=='\\' && path[2] && path[2]!='\\'
ali@435: 	    && strchr(path+3,'\\')) {
ali@435: 		/* We have a UNC path: \\servername\sharename... */
ali@435: 		const char *sharename, *root;
ali@435: 		int disklen;
ali@435: 
ali@435: 		sharename = strchr(path+3,'\\')+1;
ali@435: 		root = strchr(sharename,'\\');
ali@435: 		if (root)
ali@435: 		    disklen = root - path;
ali@435: 		else
ali@435: 		    disklen = strlen(path);
ali@435: 
ali@435: 		atomic->toplevel =
ali@435: 		  malloc(disklen + strlen("\\atomic-XXXXXX") + 1);
ali@435: 		memcpy(atomic->toplevel, path, disklen);
ali@435: 		strcpy(atomic->toplevel + disklen, "\\atomic-XXXXXX");
ali@435: 	} else if ((*path>='A' && *path<='Z' || *path>='a' && *path<='z') &&
ali@435: 		    path[1]==':') {
ali@435: 		atomic->toplevel = strdup("X:\\atomic-XXXXXX");
ali@435: 		*atomic->toplevel = *path;
ali@435: 	} else {
ali@435: 		DWORD n;
ali@435: 		wchar_t *buf;
ali@435: 		char *dir;
ali@435: 
ali@435: 		n = GetCurrentDirectoryW(0, NULL);
ali@435: 		buf = malloc(n * sizeof(wchar_t));
ali@435: 
ali@435: 		if (GetCurrentDirectoryW(n, buf)) {
ali@435: 			dir = razor_utf16_to_utf8(buf, n - 1);
ali@435: 			razor_atomic_set_toplevel_from_path(atomic, dir);
ali@435: 
ali@435: 			free(dir);
ali@435: 			free(buf);
ali@435: 			return;
ali@435: 		} else
ali@435: 			atomic->toplevel = strdup("C:\\atomic-XXXXXX");
ali@435: 
ali@435: 		free(buf);
ali@435: 	}
ali@435: #else
ali@444: 	{
ali@444: 		/*
ali@444: 		 * Find the mount point (assuming we can write to the
ali@444: 		 * whole filesystem). Otherwise stop at the first
ali@444: 		 * unwritable directory and take one step back.
ali@444: 		 */
ali@444: 		char *s, *abspath, saved;
ali@444: 		int len;
ali@444: 
ali@444: 		abspath = absolute_path(path);
ali@444: 		if (!abspath) {
ali@444: 			atomic->error = razor_error_new_str(path,
ali@444: 							    strerror(errno));
ali@444: 			return -1;
ali@444: 		}
ali@444: 
ali@444: 		if (stat(abspath, &buf) < 0) {
ali@444: 			atomic->error = razor_error_new_str(abspath,
ali@444: 							    strerror(errno));
ali@444: 			free(abspath);
ali@444: 			return -1;
ali@444: 		}
ali@444: 		filesystem = buf.st_dev;
ali@444: 
ali@444: 		len = strlen(abspath);
ali@444: 		while(len > 1 && (s = strrchr(abspath, '/'))) {
ali@444: 			if (s == abspath) {
ali@444: 				saved = s[1];
ali@444: 				s[1] = '\0';
ali@444: 				len = s + 1 - abspath;
ali@444: 			} else {
ali@444: 				s[0] = '\0';
ali@444: 				len = s - abspath;
ali@444: 			}
ali@444: 
ali@444: 			if (stat(abspath, &buf) < 0) {
ali@444: 				atomic->error =
ali@444: 				  razor_error_new_str(abspath, strerror(errno));
ali@444: 				free(abspath);
ali@444: 				return -1;
ali@444: 			}
ali@444: 
ali@444: 			if (buf.st_dev != filesystem || access(abspath, W_OK)) {
ali@444: 				if (s == abspath)
ali@444: 					s[1] = saved;
ali@444: 				else
ali@444: 					s[0] = '/';
ali@444: 				len = strlen(abspath);
ali@444: 				break;
ali@444: 			}
ali@444: 		}
ali@444: 
ali@444: 		if (len == 1)
ali@444: 			len = 0;	/* Avoid an unslightly double slash. */
ali@444: 		atomic->toplevel = malloc(len + strlen("/.atomic-XXXXXX") + 1);
ali@444: 		memcpy(atomic->toplevel, abspath, len);
ali@444: 		strcpy(atomic->toplevel + len, "/.atomic-XXXXXX");
ali@444: 
ali@444: 		free(abspath);
ali@444: 	}
ali@435: #endif
ali@435: 
ali@435: 	if (!mkdtemp(atomic->toplevel)) {
ali@435: 		int err = errno;
ali@435: 
ali@435: #ifdef EACCES
ali@435: 		if (err == EACCES) {
ali@435: 			char *s = strdup("atomic-XXXXXX");
ali@435: 
ali@444: #ifndef MSWIN_API
ali@444: 			if (stat(".", &buf) < 0) {
ali@444: 				atomic->error =
ali@444: 				  razor_error_new_str(".", strerror(errno));
ali@444: 				free(s);
ali@444: 				free(atomic->toplevel);
ali@444: 				atomic->toplevel = NULL;
ali@444: 				return -1;
ali@444: 			}
ali@444: 			if (buf.st_dev != filesystem)
ali@444: 				/*
ali@444: 				 * Don't use a different filesystem. It will
ali@444: 				 * only fail later on (in rename) and cause
ali@444: 				 * an unhelpful error message (EXDEV).
ali@444: 				 */
ali@444: 				free(s);
ali@444: 			else
ali@444: #endif
ali@435: 			if (mkdtemp(s)) {
ali@435: 				free(atomic->toplevel);
ali@435: 				atomic->toplevel = s;
ali@435: 				return 0;
ali@435: 			} else
ali@435: 				free(s);
ali@435: 		}
ali@435: #endif
ali@435: 
ali@435: 		atomic->error = razor_error_new_str(atomic->toplevel,
ali@435: 						    strerror(err));
ali@435: 
ali@435: 		free(atomic->toplevel);
ali@435: 		atomic->toplevel = NULL;
ali@435: 	}
ali@435: 
ali@435: 	return !atomic->toplevel;
ali@435: }
ali@435: 
ali@416: RAZOR_EXPORT int
ali@416: razor_atomic_make_dirs(struct razor_atomic *atomic, const char *root,
ali@416: 		       const char *path)
ali@416: {
ali@416: 	struct atomic_action *a;
ali@416: 
ali@435: 	razor_atomic_set_toplevel_from_path(atomic, *root ? root : path);
ali@435: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: 	a = atomic_action_new(ACTION_MAKE_DIRS);
ali@416: 	a->args.path = strdup(path);
ali@416: 	a->args.u.make_dirs.root = strdup(root);
ali@416: 	atomic->actions = atomic_action_list_prepend(atomic->actions, a);
ali@416: 
ali@416: 	return 0;
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT int
ali@416: razor_atomic_remove(struct razor_atomic *atomic, const char *path)
ali@416: {
ali@416: 	struct atomic_action *a;
ali@416: 
ali@435: 	razor_atomic_set_toplevel_from_path(atomic, path);
ali@435: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: 	a = atomic_action_new(ACTION_REMOVE);
ali@416: 	a->args.path = strdup(path);
ali@416: 	atomic->actions = atomic_action_list_prepend(atomic->actions, a);
ali@416: 
ali@416: 	return 0;
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT int
ali@416: razor_atomic_rename_file(struct razor_atomic *atomic, const char *oldpath,
ali@416: 			 const char *newpath)
ali@416: {
ali@416: 	struct atomic_action *a;
ali@416: 
ali@435: 	razor_atomic_set_toplevel_from_path(atomic, newpath);
ali@435: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: 	a = atomic_action_new(ACTION_MOVE);
ali@416: 	a->args.path = strdup(oldpath);
ali@416: 	a->args.u.move.dest = strdup(newpath);
ali@416: 	atomic->actions = atomic_action_list_prepend(atomic->actions, a);
ali@416: 
ali@416: 	return 0;
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT int
ali@416: razor_atomic_create_dir(struct razor_atomic *atomic, const char *dirname,
ali@416: 			mode_t mode)
ali@416: {
ali@416: 	struct atomic_action *a;
ali@416: 
ali@435: 	razor_atomic_set_toplevel_from_path(atomic, dirname);
ali@435: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: 	a = atomic_action_new(ACTION_CREATE_DIR);
ali@416: 	a->args.path = strdup(dirname);
ali@416: 	a->args.u.create_dir.mode = mode;
ali@416: 	atomic->actions = atomic_action_list_prepend(atomic->actions, a);
ali@416: 
ali@416: 	return 0;
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT int
ali@416: razor_atomic_create_symlink(struct razor_atomic *atomic, const char *target,
ali@416: 			    const char *path)
ali@416: {
ali@416: #if HAVE_SYMLINK
ali@416: 	struct atomic_action *a;
ali@435: 
ali@435: 	razor_atomic_set_toplevel_from_path(atomic, path);
ali@416: #endif
ali@416: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: #if HAVE_SYMLINK
ali@416: 	a = atomic_action_new(ACTION_CREATE_SYMLINK);
ali@416: 	a->args.path = strdup(path);
ali@416: 	a->args.u.create_symlink.target = strdup(target);
ali@416: 	atomic->actions = atomic_action_list_prepend(atomic->actions, a);
ali@416: 
ali@416: 	return 0;
ali@416: #else
ali@423: 	atomic->error = razor_error_new_str(NULL,
ali@423: 					    "Symbolic links not supported "
ali@423: 					    "on this platform");
ali@416: 
ali@416: 	return -1;
ali@416: #endif
ali@416: }
ali@416: 
ali@416: RAZOR_EXPORT int
ali@416: razor_atomic_create_file(struct razor_atomic *atomic, const char *filename,
ali@416:                          mode_t mode)
ali@416: {
ali@416: 	int fd;
ali@416: 	struct atomic_action *a;
ali@416: 	char *tmpnam;
ali@416: 
ali@435: 	razor_atomic_set_toplevel_from_path(atomic, filename);
ali@435: 
ali@416: 	if (razor_atomic_in_error_state(atomic))
ali@416: 		return -1;
ali@416: 
ali@416: 	tmpnam = atomic_action_attic_tmpnam(atomic);
ali@416: 	fd = open(tmpnam, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
ali@416: 		  mode & (S_IRWXU | S_IRWXG | S_IRWXO));
ali@416: 
ali@416: 	if (fd == -1)
ali@423: 		atomic->error = razor_error_new_str(filename, strerror(errno));
ali@416: 	else {
ali@416: 		a = atomic_action_new(ACTION_MOVE);
ali@416: 		a->args.path = tmpnam;
ali@416: 		a->args.u.move.dest = strdup(filename);
ali@416: 		atomic->actions = atomic_action_list_prepend(atomic->actions,
ali@416: 							     a);
ali@416: 	}
ali@416: 
ali@416: 	return fd;
ali@416: }
ali@416: 
ali@416: #endif	/* ENABLE_ATOMIC && !HAVE_WINDOWS_KTM */