/*
- $Id: unix.c,v 1.3 2010-01-26 08:05:17 didg Exp $
Copyright (c) 2010 Frank Lahm <franklahm@gmail.com>
This program is free software; you can redistribute it and/or modify
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
+#include <sys/time.h>
+#include <time.h>
#include <atalk/adouble.h>
#include <atalk/ea.h>
#include <atalk/afp.h>
#include <atalk/logger.h>
-#include <atalk/volume.h>
#include <atalk/vfs.h>
#include <atalk/util.h>
#include <atalk/unix.h>
+/* close all FDs >= a specified value */
+static void closeall(int fd)
+{
+ int fdlimit = sysconf(_SC_OPEN_MAX);
+
+ while (fd < fdlimit)
+ close(fd++);
+}
+
+/*!
+ * Daemonize
+ *
+ * Fork, exit parent, setsid(), optionally chdir("/"), optionally close all fds
+ *
+ * returns -1 on failure, but you can't do much except exit in that case
+ * since we may already have forked
+ */
+int daemonize(int nochdir, int noclose)
+{
+ switch (fork()) {
+ case 0:
+ break;
+ case -1:
+ return -1;
+ default:
+ _exit(0);
+ }
+
+ if (setsid() < 0)
+ return -1;
+
+ switch (fork()) {
+ case 0:
+ break;
+ case -1:
+ return -1;
+ default:
+ _exit(0);
+ }
+
+ if (!nochdir)
+ chdir("/");
+
+ if (!noclose) {
+ closeall(0);
+ open("/dev/null",O_RDWR);
+ dup(0);
+ dup(0);
+ }
+
+ return 0;
+}
+
+static uid_t saved_uid = -1;
+
+void become_root(void)
+{
+ saved_uid = geteuid();
+ if (seteuid(0) != 0)
+ AFP_PANIC("Can't seteuid(0)");
+}
+
+void unbecome_root(void)
+{
+ if (saved_uid == -1 || seteuid(saved_uid) < 0)
+ AFP_PANIC("Can't seteuid back");
+ saved_uid = -1;
+}
+
/*!
* @brief get cwd in static buffer
*
* @returns pointer to path or pointer to error messages on error
*/
-extern const char *getcwdpath(void)
+const char *getcwdpath(void)
{
static char cwd[MAXPATHLEN + 1];
char *p;
else
return strerror(errno);
}
+
+/*!
+ * @brief Request absolute path
+ *
+ * @returns Absolute filesystem path to object
+ */
+const char *fullpathname(const char *name)
+{
+ static char wd[MAXPATHLEN + 1];
+
+ if (name[0] == '/')
+ return name;
+
+ if (getcwd(wd , MAXPATHLEN)) {
+ strlcat(wd, "/", MAXPATHLEN);
+ strlcat(wd, name, MAXPATHLEN);
+ } else {
+ strlcpy(wd, name, MAXPATHLEN);
+ }
+
+ return wd;
+}
+
+/*!
+ * Takes a buffer with a path, strips slashs, returns basename
+ *
+ * @param p (rw) path
+ * path may be
+ * "[/][dir/[...]]file"
+ * or
+ * "[/][dir/[...]]dir/[/]"
+ * Result is "file" or "dir"
+ *
+ * @returns pointer to basename in path buffer, buffer is possibly modified
+ */
+char *stripped_slashes_basename(char *p)
+{
+ int i = strlen(p) - 1;
+ while (i > 0 && p[i] == '/')
+ p[i--] = 0;
+ return (strrchr(p, '/') ? strrchr(p, '/') + 1 : p);
+}
+
+/*********************************************************************************
+ * chdir(), chmod(), chown(), stat() wrappers taking an additional option.
+ * Currently the only used options are O_NOFOLLOW, used to switch between symlink
+ * behaviour, and O_NETATALK_ACL for ochmod() indicating chmod_acl() shall be
+ * called which does special ACL handling depending on the filesytem
+ *********************************************************************************/
+
+int ostat(const char *path, struct stat *buf, int options)
+{
+ if (options & O_NOFOLLOW)
+ return lstat(path, buf);
+ else
+ return stat(path, buf);
+}
+
+int ochown(const char *path, uid_t owner, gid_t group, int options)
+{
+ if (options & O_NOFOLLOW)
+ return lchown(path, owner, group);
+ else
+ return chown(path, owner, group);
+}
+
+/*!
+ * chmod() wrapper for symlink and ACL handling
+ *
+ * @param path (r) path
+ * @param mode (r) requested mode
+ * @param sb (r) stat() of path or NULL
+ * @param option (r) O_NOFOLLOW | O_NETATALK_ACL
+ *
+ * Options description:
+ * O_NOFOLLOW: don't chmod() symlinks, do nothing, return 0
+ * O_NETATALK_ACL: call chmod_acl() instead of chmod()
+ */
+int ochmod(const char *path, mode_t mode, const struct stat *st, int options)
+{
+ struct stat sb;
+
+ if (!st) {
+ if (lstat(path, &sb) != 0)
+ return -1;
+ st = &sb;
+ }
+
+ if (options & O_NOFOLLOW)
+ if (S_ISLNK(st->st_mode))
+ return 0;
+
+ if (options & O_NETATALK_ACL) {
+ return chmod_acl(path, mode);
+ } else {
+ return chmod(path, mode);
+ }
+}
+
+/*
+ * @brief ostat/fsstatat multiplexer
+ *
+ * ostatat mulitplexes ostat and fstatat. If we dont HAVE_ATFUNCS, dirfd is ignored.
+ *
+ * @param dirfd (r) Only used if HAVE_ATFUNCS, ignored else, -1 gives AT_FDCWD
+ * @param path (r) pathname
+ * @param st (rw) pointer to struct stat
+ */
+int ostatat(int dirfd, const char *path, struct stat *st, int options)
+{
+#ifdef HAVE_ATFUNCS
+ if (dirfd == -1)
+ dirfd = AT_FDCWD;
+ return fstatat(dirfd, path, st, (options & O_NOFOLLOW) ? AT_SYMLINK_NOFOLLOW : 0);
+#else
+ return ostat(path, st, options);
+#endif
+
+ /* DEADC0DE */
+ return -1;
+}
+
+/*!
+ * @brief symlink safe chdir replacement
+ *
+ * Only chdirs to dir if it doesn't contain symlinks or if symlink checking
+ * is disabled
+ *
+ * @returns 1 if a path element is a symlink, 0 otherwise, -1 on syserror
+ */
+int ochdir(const char *dir, int options)
+{
+ char buf[MAXPATHLEN+1];
+ char cwd[MAXPATHLEN+1];
+ char *test;
+ int i;
+
+ if (!(options & O_NOFOLLOW))
+ return chdir(dir);
+
+ /*
+ dir is a canonical path (without "../" "./" "//" )
+ but may end with a /
+ */
+ *cwd = 0;
+ if (*dir != '/') {
+ if (getcwd(cwd, MAXPATHLEN) == NULL)
+ return -1;
+ }
+ if (chdir(dir) != 0)
+ return -1;
+
+ /*
+ * Cases:
+ * chdir request | realpath result | ret
+ * (after getwcwd) | |
+ * =======================================
+ * /a/b/. | /a/b | 0
+ * /a/b/. | /c | 1
+ * /a/b/. | /c/d/e/f | 1
+ */
+ if (getcwd(buf, MAXPATHLEN) == NULL)
+ return 1;
+
+ i = 0;
+ if (*cwd) {
+ /* relative path requested,
+ * Same directory?
+ */
+ for (; cwd[i]; i++) {
+ if (buf[i] != cwd[i])
+ return 1;
+ }
+ if (buf[i]) {
+ if (buf[i] != '/')
+ return 1;
+ i++;
+ }
+ }
+
+ test = &buf[i];
+ for (i = 0; test[i]; i++) {
+ if (test[i] != dir[i]) {
+ return 1;
+ }
+ }
+ /* trailing '/' ? */
+ if (!dir[i])
+ return 0;
+
+ if (dir[i] != '/')
+ return 1;
+
+ i++;
+ if (dir[i])
+ return 1;
+
+ return 0;
+}
+
+/*!
+ * Store n random bytes an buf
+ */
+void randombytes(void *buf, int n)
+{
+ char *p = (char *)buf;
+ int fd, i;
+ struct timeval tv;
+
+ if ((fd = open("/dev/urandom", O_RDONLY)) != -1) {
+ /* generate from /dev/urandom */
+ if (read(fd, buf, n) != n) {
+ close(fd);
+ fd = -1;
+ } else {
+ close(fd);
+ /* fd now != -1, so srandom wont be called below */
+ }
+ }
+
+ if (fd == -1) {
+ gettimeofday(&tv, NULL);
+ srandom((unsigned int)tv.tv_usec);
+ for (i=0 ; i < n ; i++)
+ p[i] = random() & 0xFF;
+ }
+
+ return;
+}
projects / netatalk.git / blobdiff