950 lines
20 KiB
C
950 lines
20 KiB
C
/*
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* Copyright (c) 1998-2000 Sendmail, Inc. and its suppliers.
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* All rights reserved.
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* Copyright (c) 1983, 1995-1997 Eric P. Allman. All rights reserved.
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* Copyright (c) 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* By using this file, you agree to the terms and conditions set
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* forth in the LICENSE file which can be found at the top level of
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* the sendmail distribution.
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*
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*/
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#ifndef lint
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static char id[] = "@(#)$Id: safefile.c,v 8.81.4.7 2000/09/01 21:09:23 ca Exp $";
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#endif /* ! lint */
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#include <sendmail.h>
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/*
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** SAFEFILE -- return 0 if a file exists and is safe for a user.
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**
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** Parameters:
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** fn -- filename to check.
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** uid -- user id to compare against.
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** gid -- group id to compare against.
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** user -- user name to compare against (used for group
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** sets).
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** flags -- modifiers:
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** SFF_MUSTOWN -- "uid" must own this file.
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** SFF_NOSLINK -- file cannot be a symbolic link.
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** mode -- mode bits that must match.
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** st -- if set, points to a stat structure that will
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** get the stat info for the file.
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**
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** Returns:
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** 0 if fn exists, is owned by uid, and matches mode.
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** An errno otherwise. The actual errno is cleared.
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**
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** Side Effects:
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** none.
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*/
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int
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safefile(fn, uid, gid, user, flags, mode, st)
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char *fn;
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UID_T uid;
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GID_T gid;
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char *user;
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long flags;
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int mode;
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struct stat *st;
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{
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register char *p;
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register struct group *gr = NULL;
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int file_errno = 0;
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bool checkpath;
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struct stat stbuf;
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struct stat fstbuf;
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char fbuf[MAXPATHLEN + 1];
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if (tTd(44, 4))
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dprintf("safefile(%s, uid=%d, gid=%d, flags=%lx, mode=%o):\n",
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fn, (int) uid, (int) gid, flags, mode);
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errno = 0;
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if (st == NULL)
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st = &fstbuf;
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if (strlcpy(fbuf, fn, sizeof fbuf) >= sizeof fbuf)
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{
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if (tTd(44, 4))
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dprintf("\tpathname too long\n");
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return ENAMETOOLONG;
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}
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fn = fbuf;
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/* ignore SFF_SAFEDIRPATH if we are debugging */
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if (RealUid != 0 && RunAsUid == RealUid)
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flags &= ~SFF_SAFEDIRPATH;
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/* first check to see if the file exists at all */
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# if HASLSTAT
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if ((bitset(SFF_NOSLINK, flags) ? lstat(fn, st)
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: stat(fn, st)) < 0)
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# else /* HASLSTAT */
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if (stat(fn, st) < 0)
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# endif /* HASLSTAT */
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{
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file_errno = errno;
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}
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else if (bitset(SFF_SETUIDOK, flags) &&
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!bitset(S_IXUSR|S_IXGRP|S_IXOTH, st->st_mode) &&
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S_ISREG(st->st_mode))
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{
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/*
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** If final file is setuid, run as the owner of that
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** file. Gotta be careful not to reveal anything too
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** soon here!
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*/
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# ifdef SUID_ROOT_FILES_OK
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if (bitset(S_ISUID, st->st_mode))
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# else /* SUID_ROOT_FILES_OK */
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if (bitset(S_ISUID, st->st_mode) && st->st_uid != 0 &&
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st->st_uid != TrustedUid)
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# endif /* SUID_ROOT_FILES_OK */
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{
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uid = st->st_uid;
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user = NULL;
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}
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# ifdef SUID_ROOT_FILES_OK
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if (bitset(S_ISGID, st->st_mode))
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# else /* SUID_ROOT_FILES_OK */
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if (bitset(S_ISGID, st->st_mode) && st->st_gid != 0)
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# endif /* SUID_ROOT_FILES_OK */
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gid = st->st_gid;
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}
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checkpath = !bitset(SFF_NOPATHCHECK, flags) ||
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(uid == 0 && !bitset(SFF_ROOTOK|SFF_OPENASROOT, flags));
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if (bitset(SFF_NOWLINK, flags) && !bitset(SFF_SAFEDIRPATH, flags))
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{
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int ret;
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/* check the directory */
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p = strrchr(fn, '/');
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if (p == NULL)
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{
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ret = safedirpath(".", uid, gid, user,
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flags|SFF_SAFEDIRPATH, 0, 0);
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}
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else
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{
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*p = '\0';
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ret = safedirpath(fn, uid, gid, user,
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flags|SFF_SAFEDIRPATH, 0, 0);
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*p = '/';
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}
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if (ret == 0)
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{
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/* directory is safe */
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checkpath = FALSE;
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}
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else
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{
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# if HASLSTAT
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/* Need lstat() information if called stat() before */
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if (!bitset(SFF_NOSLINK, flags) && lstat(fn, st) < 0)
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{
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ret = errno;
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if (tTd(44, 4))
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dprintf("\t%s\n", errstring(ret));
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return ret;
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}
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# endif /* HASLSTAT */
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/* directory is writable: disallow links */
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flags |= SFF_NOLINK;
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}
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}
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if (checkpath)
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{
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int ret;
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p = strrchr(fn, '/');
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if (p == NULL)
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{
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ret = safedirpath(".", uid, gid, user, flags, 0, 0);
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}
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else
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{
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*p = '\0';
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ret = safedirpath(fn, uid, gid, user, flags, 0, 0);
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*p = '/';
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}
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if (ret != 0)
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return ret;
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}
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/*
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** If the target file doesn't exist, check the directory to
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** ensure that it is writable by this user.
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*/
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if (file_errno != 0)
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{
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int ret = file_errno;
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char *dir = fn;
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if (tTd(44, 4))
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dprintf("\t%s\n", errstring(ret));
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errno = 0;
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if (!bitset(SFF_CREAT, flags) || file_errno != ENOENT)
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return ret;
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/* check to see if legal to create the file */
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p = strrchr(dir, '/');
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if (p == NULL)
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dir = ".";
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else if (p == dir)
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dir = "/";
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else
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*p = '\0';
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if (stat(dir, &stbuf) >= 0)
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{
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int md = S_IWRITE|S_IEXEC;
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if (stbuf.st_uid == uid)
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/* EMPTY */
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;
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else if (uid == 0 && stbuf.st_uid == TrustedUid)
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/* EMPTY */
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;
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else
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{
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md >>= 3;
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if (stbuf.st_gid == gid)
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/* EMPTY */
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;
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# ifndef NO_GROUP_SET
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else if (user != NULL && !DontInitGroups &&
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((gr != NULL &&
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gr->gr_gid == stbuf.st_gid) ||
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(gr = getgrgid(stbuf.st_gid)) != NULL))
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{
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register char **gp;
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for (gp = gr->gr_mem; *gp != NULL; gp++)
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if (strcmp(*gp, user) == 0)
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break;
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if (*gp == NULL)
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md >>= 3;
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}
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# endif /* ! NO_GROUP_SET */
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else
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md >>= 3;
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}
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if ((stbuf.st_mode & md) != md)
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errno = EACCES;
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}
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ret = errno;
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if (tTd(44, 4))
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dprintf("\t[final dir %s uid %d mode %lo] %s\n",
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dir, (int) stbuf.st_uid, (u_long) stbuf.st_mode,
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errstring(ret));
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if (p != NULL)
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*p = '/';
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st->st_mode = ST_MODE_NOFILE;
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return ret;
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}
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# ifdef S_ISLNK
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if (bitset(SFF_NOSLINK, flags) && S_ISLNK(st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[slink mode %lo]\tE_SM_NOSLINK\n",
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(u_long) st->st_mode);
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return E_SM_NOSLINK;
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}
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# endif /* S_ISLNK */
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if (bitset(SFF_REGONLY, flags) && !S_ISREG(st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[non-reg mode %lo]\tE_SM_REGONLY\n",
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(u_long) st->st_mode);
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return E_SM_REGONLY;
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}
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if (bitset(SFF_NOGWFILES, flags) &&
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bitset(S_IWGRP, st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[write bits %lo]\tE_SM_GWFILE\n",
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(u_long) st->st_mode);
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return E_SM_GWFILE;
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}
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if (bitset(SFF_NOWWFILES, flags) &&
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bitset(S_IWOTH, st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[write bits %lo]\tE_SM_WWFILE\n",
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(u_long) st->st_mode);
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return E_SM_WWFILE;
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}
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if (bitset(SFF_NOGRFILES, flags) && bitset(S_IRGRP, st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[read bits %lo]\tE_SM_GRFILE\n",
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(u_long) st->st_mode);
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return E_SM_GRFILE;
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}
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if (bitset(SFF_NOWRFILES, flags) && bitset(S_IROTH, st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[read bits %lo]\tE_SM_WRFILE\n",
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(u_long) st->st_mode);
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return E_SM_WRFILE;
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}
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if (!bitset(SFF_EXECOK, flags) &&
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bitset(S_IWUSR|S_IWGRP|S_IWOTH, mode) &&
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bitset(S_IXUSR|S_IXGRP|S_IXOTH, st->st_mode))
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{
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if (tTd(44, 4))
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dprintf("\t[exec bits %lo]\tE_SM_ISEXEC]\n",
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(u_long) st->st_mode);
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return E_SM_ISEXEC;
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}
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if (bitset(SFF_NOHLINK, flags) && st->st_nlink != 1)
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{
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if (tTd(44, 4))
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dprintf("\t[link count %d]\tE_SM_NOHLINK\n",
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(int) st->st_nlink);
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return E_SM_NOHLINK;
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}
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if (uid == 0 && bitset(SFF_OPENASROOT, flags))
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/* EMPTY */
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;
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else if (uid == 0 && !bitset(SFF_ROOTOK, flags))
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mode >>= 6;
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else if (st->st_uid == uid)
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/* EMPTY */
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;
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else if (uid == 0 && st->st_uid == TrustedUid)
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/* EMPTY */
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;
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else
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{
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mode >>= 3;
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if (st->st_gid == gid)
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/* EMPTY */
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;
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# ifndef NO_GROUP_SET
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else if (user != NULL && !DontInitGroups &&
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((gr != NULL && gr->gr_gid == st->st_gid) ||
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(gr = getgrgid(st->st_gid)) != NULL))
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{
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register char **gp;
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for (gp = gr->gr_mem; *gp != NULL; gp++)
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if (strcmp(*gp, user) == 0)
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break;
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if (*gp == NULL)
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mode >>= 3;
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}
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# endif /* ! NO_GROUP_SET */
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else
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mode >>= 3;
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}
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if (tTd(44, 4))
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dprintf("\t[uid %d, nlink %d, stat %lo, mode %lo] ",
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(int) st->st_uid, (int) st->st_nlink,
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(u_long) st->st_mode, (u_long) mode);
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if ((st->st_uid == uid || st->st_uid == 0 ||
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st->st_uid == TrustedUid ||
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!bitset(SFF_MUSTOWN, flags)) &&
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(st->st_mode & mode) == mode)
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{
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if (tTd(44, 4))
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dprintf("\tOK\n");
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return 0;
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}
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if (tTd(44, 4))
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dprintf("\tEACCES\n");
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return EACCES;
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}
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/*
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** SAFEDIRPATH -- check to make sure a path to a directory is safe
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**
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** Safe means not writable and owned by the right folks.
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**
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** Parameters:
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** fn -- filename to check.
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** uid -- user id to compare against.
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** gid -- group id to compare against.
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** user -- user name to compare against (used for group
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** sets).
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** flags -- modifiers:
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** SFF_ROOTOK -- ok to use root permissions to open.
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** SFF_SAFEDIRPATH -- writable directories are considered
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** to be fatal errors.
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** level -- symlink recursive level.
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** offset -- offset into fn to start checking from.
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**
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** Returns:
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** 0 -- if the directory path is "safe".
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** else -- an error number associated with the path.
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*/
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int
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safedirpath(fn, uid, gid, user, flags, level, offset)
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char *fn;
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UID_T uid;
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GID_T gid;
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char *user;
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long flags;
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int level;
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int offset;
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{
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int ret = 0;
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int mode = S_IWOTH;
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char save = '\0';
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char *saveptr = NULL;
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char *p, *enddir;
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register struct group *gr = NULL;
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char s[MAXLINKPATHLEN + 1];
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struct stat stbuf;
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/* make sure we aren't in a symlink loop */
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if (level > MAXSYMLINKS)
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return ELOOP;
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/* special case root directory */
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if (*fn == '\0')
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fn = "/";
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if (tTd(44, 4))
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dprintf("safedirpath(%s, uid=%ld, gid=%ld, flags=%lx, level=%d, offset=%d):\n",
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fn, (long) uid, (long) gid, flags, level, offset);
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if (!bitnset(DBS_GROUPWRITABLEDIRPATHSAFE, DontBlameSendmail))
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mode |= S_IWGRP;
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/* Make a modifiable copy of the filename */
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if (strlcpy(s, fn, sizeof s) >= sizeof s)
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return EINVAL;
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p = s + offset;
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while (p != NULL)
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{
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/* put back character */
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if (saveptr != NULL)
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{
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*saveptr = save;
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saveptr = NULL;
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p++;
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}
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if (*p == '\0')
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break;
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p = strchr(p, '/');
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/* Special case for root directory */
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if (p == s)
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{
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save = *(p + 1);
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saveptr = p + 1;
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*(p + 1) = '\0';
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}
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else if (p != NULL)
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{
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save = *p;
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saveptr = p;
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*p = '\0';
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}
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/* Heuristic: . and .. have already been checked */
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enddir = strrchr(s, '/');
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if (enddir != NULL &&
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(strcmp(enddir, "/..") == 0 ||
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strcmp(enddir, "/.") == 0))
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continue;
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if (tTd(44, 20))
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dprintf("\t[dir %s]\n", s);
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# if HASLSTAT
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ret = lstat(s, &stbuf);
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# else /* HASLSTAT */
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ret = stat(s, &stbuf);
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# endif /* HASLSTAT */
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if (ret < 0)
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{
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ret = errno;
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break;
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}
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# ifdef S_ISLNK
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/* Follow symlinks */
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if (S_ISLNK(stbuf.st_mode))
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{
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char *target;
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char buf[MAXPATHLEN + 1];
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memset(buf, '\0', sizeof buf);
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if (readlink(s, buf, sizeof buf) < 0)
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{
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ret = errno;
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break;
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}
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offset = 0;
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if (*buf == '/')
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{
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target = buf;
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/* If path is the same, avoid rechecks */
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while (s[offset] == buf[offset] &&
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s[offset] != '\0')
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offset++;
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if (s[offset] == '\0' && buf[offset] == '\0')
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{
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/* strings match, symlink loop */
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return ELOOP;
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}
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/* back off from the mismatch */
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if (offset > 0)
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offset--;
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/* Make sure we are at a directory break */
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if (offset > 0 &&
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s[offset] != '/' &&
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s[offset] != '\0')
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{
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while (buf[offset] != '/' &&
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offset > 0)
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offset--;
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}
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if (offset > 0 &&
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s[offset] == '/' &&
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buf[offset] == '/')
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{
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/* Include the trailing slash */
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offset++;
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}
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}
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else
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{
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char *sptr;
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char fullbuf[MAXLINKPATHLEN + 1];
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sptr = strrchr(s, '/');
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if (sptr != NULL)
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{
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*sptr = '\0';
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offset = sptr + 1 - s;
|
||
if ((strlen(s) + 1 +
|
||
strlen(buf) + 1) > sizeof fullbuf)
|
||
{
|
||
ret = EINVAL;
|
||
break;
|
||
}
|
||
snprintf(fullbuf, sizeof fullbuf,
|
||
"%s/%s", s, buf);
|
||
*sptr = '/';
|
||
}
|
||
else
|
||
{
|
||
if (strlen(buf) + 1 > sizeof fullbuf)
|
||
{
|
||
ret = EINVAL;
|
||
break;
|
||
}
|
||
(void) strlcpy(fullbuf, buf,
|
||
sizeof fullbuf);
|
||
}
|
||
target = fullbuf;
|
||
}
|
||
ret = safedirpath(target, uid, gid, user, flags,
|
||
level + 1, offset);
|
||
if (ret != 0)
|
||
break;
|
||
|
||
/* Don't check permissions on the link file itself */
|
||
continue;
|
||
}
|
||
#endif /* S_ISLNK */
|
||
|
||
if ((uid == 0 || bitset(SFF_SAFEDIRPATH, flags)) &&
|
||
#ifdef S_ISVTX
|
||
!(bitnset(DBS_TRUSTSTICKYBIT, DontBlameSendmail) &&
|
||
bitset(S_ISVTX, stbuf.st_mode)) &&
|
||
#endif /* S_ISVTX */
|
||
bitset(mode, stbuf.st_mode))
|
||
{
|
||
if (tTd(44, 4))
|
||
dprintf("\t[dir %s] mode %lo ",
|
||
s, (u_long) stbuf.st_mode);
|
||
if (bitset(SFF_SAFEDIRPATH, flags))
|
||
{
|
||
if (bitset(S_IWOTH, stbuf.st_mode))
|
||
ret = E_SM_WWDIR;
|
||
else
|
||
ret = E_SM_GWDIR;
|
||
if (tTd(44, 4))
|
||
dprintf("FATAL\n");
|
||
break;
|
||
}
|
||
if (tTd(44, 4))
|
||
dprintf("WARNING\n");
|
||
if (Verbose > 1)
|
||
message("051 WARNING: %s writable directory %s",
|
||
bitset(S_IWOTH, stbuf.st_mode)
|
||
? "World"
|
||
: "Group",
|
||
s);
|
||
}
|
||
if (uid == 0 && !bitset(SFF_ROOTOK|SFF_OPENASROOT, flags))
|
||
{
|
||
if (bitset(S_IXOTH, stbuf.st_mode))
|
||
continue;
|
||
ret = EACCES;
|
||
break;
|
||
}
|
||
|
||
/*
|
||
** Let OS determine access to file if we are not
|
||
** running as a privileged user. This allows ACLs
|
||
** to work. Also, if opening as root, assume we can
|
||
** scan the directory.
|
||
*/
|
||
if (geteuid() != 0 || bitset(SFF_OPENASROOT, flags))
|
||
continue;
|
||
|
||
if (stbuf.st_uid == uid &&
|
||
bitset(S_IXUSR, stbuf.st_mode))
|
||
continue;
|
||
if (stbuf.st_gid == gid &&
|
||
bitset(S_IXGRP, stbuf.st_mode))
|
||
continue;
|
||
# ifndef NO_GROUP_SET
|
||
if (user != NULL && !DontInitGroups &&
|
||
((gr != NULL && gr->gr_gid == stbuf.st_gid) ||
|
||
(gr = getgrgid(stbuf.st_gid)) != NULL))
|
||
{
|
||
register char **gp;
|
||
|
||
for (gp = gr->gr_mem; gp != NULL && *gp != NULL; gp++)
|
||
if (strcmp(*gp, user) == 0)
|
||
break;
|
||
if (gp != NULL && *gp != NULL &&
|
||
bitset(S_IXGRP, stbuf.st_mode))
|
||
continue;
|
||
}
|
||
# endif /* ! NO_GROUP_SET */
|
||
if (!bitset(S_IXOTH, stbuf.st_mode))
|
||
{
|
||
ret = EACCES;
|
||
break;
|
||
}
|
||
}
|
||
if (tTd(44, 4))
|
||
dprintf("\t[dir %s] %s\n", fn,
|
||
ret == 0 ? "OK" : errstring(ret));
|
||
return ret;
|
||
}
|
||
/*
|
||
** SAFEOPEN -- do a file open with extra checking
|
||
**
|
||
** Parameters:
|
||
** fn -- the file name to open.
|
||
** omode -- the open-style mode flags.
|
||
** cmode -- the create-style mode flags.
|
||
** sff -- safefile flags.
|
||
**
|
||
** Returns:
|
||
** Same as open.
|
||
*/
|
||
|
||
#ifndef O_ACCMODE
|
||
# define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR)
|
||
#endif /* ! O_ACCMODE */
|
||
|
||
int
|
||
safeopen(fn, omode, cmode, sff)
|
||
char *fn;
|
||
int omode;
|
||
int cmode;
|
||
long sff;
|
||
{
|
||
int rval;
|
||
int fd;
|
||
int smode;
|
||
struct stat stb;
|
||
|
||
if (tTd(44, 10))
|
||
printf("safeopen: fn=%s, omode=%x, cmode=%x, sff=%lx\n",
|
||
fn, omode, cmode, sff);
|
||
|
||
if (bitset(O_CREAT, omode))
|
||
sff |= SFF_CREAT;
|
||
omode &= ~O_CREAT;
|
||
smode = 0;
|
||
switch (omode & O_ACCMODE)
|
||
{
|
||
case O_RDONLY:
|
||
smode = S_IREAD;
|
||
break;
|
||
|
||
case O_WRONLY:
|
||
smode = S_IWRITE;
|
||
break;
|
||
|
||
case O_RDWR:
|
||
smode = S_IREAD|S_IWRITE;
|
||
break;
|
||
|
||
default:
|
||
smode = 0;
|
||
break;
|
||
}
|
||
if (bitset(SFF_OPENASROOT, sff))
|
||
rval = safefile(fn, RunAsUid, RunAsGid, RunAsUserName,
|
||
sff, smode, &stb);
|
||
else
|
||
rval = safefile(fn, RealUid, RealGid, RealUserName,
|
||
sff, smode, &stb);
|
||
if (rval != 0)
|
||
{
|
||
errno = rval;
|
||
return -1;
|
||
}
|
||
if (stb.st_mode == ST_MODE_NOFILE && bitset(SFF_CREAT, sff))
|
||
omode |= O_CREAT | (bitset(SFF_NOTEXCL, sff) ? 0 : O_EXCL);
|
||
else if (bitset(SFF_CREAT, sff) && bitset(O_EXCL, omode))
|
||
{
|
||
/* The file exists so an exclusive create would fail */
|
||
errno = EEXIST;
|
||
return -1;
|
||
}
|
||
|
||
fd = dfopen(fn, omode, cmode, sff);
|
||
if (fd < 0)
|
||
return fd;
|
||
if (filechanged(fn, fd, &stb))
|
||
{
|
||
syserr("554 5.3.0 cannot open: file %s changed after open", fn);
|
||
(void) close(fd);
|
||
errno = E_SM_FILECHANGE;
|
||
return -1;
|
||
}
|
||
return fd;
|
||
}
|
||
/*
|
||
** SAFEFOPEN -- do a file open with extra checking
|
||
**
|
||
** Parameters:
|
||
** fn -- the file name to open.
|
||
** omode -- the open-style mode flags.
|
||
** cmode -- the create-style mode flags.
|
||
** sff -- safefile flags.
|
||
**
|
||
** Returns:
|
||
** Same as fopen.
|
||
*/
|
||
|
||
FILE *
|
||
safefopen(fn, omode, cmode, sff)
|
||
char *fn;
|
||
int omode;
|
||
int cmode;
|
||
long sff;
|
||
{
|
||
int fd;
|
||
int save_errno;
|
||
FILE *fp;
|
||
char *fmode;
|
||
|
||
switch (omode & O_ACCMODE)
|
||
{
|
||
case O_RDONLY:
|
||
fmode = "r";
|
||
break;
|
||
|
||
case O_WRONLY:
|
||
if (bitset(O_APPEND, omode))
|
||
fmode = "a";
|
||
else
|
||
fmode = "w";
|
||
break;
|
||
|
||
case O_RDWR:
|
||
if (bitset(O_TRUNC, omode))
|
||
fmode = "w+";
|
||
else if (bitset(O_APPEND, omode))
|
||
fmode = "a+";
|
||
else
|
||
fmode = "r+";
|
||
break;
|
||
|
||
default:
|
||
syserr("554 5.3.5 safefopen: unknown omode %o", omode);
|
||
fmode = "x";
|
||
}
|
||
fd = safeopen(fn, omode, cmode, sff);
|
||
if (fd < 0)
|
||
{
|
||
save_errno = errno;
|
||
if (tTd(44, 10))
|
||
dprintf("safefopen: safeopen failed: %s\n",
|
||
errstring(errno));
|
||
errno = save_errno;
|
||
return NULL;
|
||
}
|
||
fp = fdopen(fd, fmode);
|
||
if (fp != NULL)
|
||
return fp;
|
||
|
||
save_errno = errno;
|
||
if (tTd(44, 10))
|
||
{
|
||
dprintf("safefopen: fdopen(%s, %s) failed: omode=%x, sff=%lx, err=%s\n",
|
||
fn, fmode, omode, sff, errstring(errno));
|
||
}
|
||
(void) close(fd);
|
||
errno = save_errno;
|
||
return NULL;
|
||
}
|
||
/*
|
||
** FILECHANGED -- check to see if file changed after being opened
|
||
**
|
||
** Parameters:
|
||
** fn -- pathname of file to check.
|
||
** fd -- file descriptor to check.
|
||
** stb -- stat structure from before open.
|
||
**
|
||
** Returns:
|
||
** TRUE -- if a problem was detected.
|
||
** FALSE -- if this file is still the same.
|
||
*/
|
||
|
||
bool
|
||
filechanged(fn, fd, stb)
|
||
char *fn;
|
||
int fd;
|
||
struct stat *stb;
|
||
{
|
||
struct stat sta;
|
||
|
||
if (stb->st_mode == ST_MODE_NOFILE)
|
||
{
|
||
# if HASLSTAT && BOGUS_O_EXCL
|
||
/* only necessary if exclusive open follows symbolic links */
|
||
if (lstat(fn, stb) < 0 || stb->st_nlink != 1)
|
||
return TRUE;
|
||
# else /* HASLSTAT && BOGUS_O_EXCL */
|
||
return FALSE;
|
||
# endif /* HASLSTAT && BOGUS_O_EXCL */
|
||
}
|
||
if (fstat(fd, &sta) < 0)
|
||
return TRUE;
|
||
|
||
if (sta.st_nlink != stb->st_nlink ||
|
||
sta.st_dev != stb->st_dev ||
|
||
sta.st_ino != stb->st_ino ||
|
||
# if HAS_ST_GEN && 0 /* AFS returns garbage in st_gen */
|
||
sta.st_gen != stb->st_gen ||
|
||
# endif /* HAS_ST_GEN && 0 */
|
||
sta.st_uid != stb->st_uid ||
|
||
sta.st_gid != stb->st_gid)
|
||
{
|
||
if (tTd(44, 8))
|
||
{
|
||
dprintf("File changed after opening:\n");
|
||
dprintf(" nlink = %ld/%ld\n",
|
||
(long) stb->st_nlink, (long) sta.st_nlink);
|
||
dprintf(" dev = %ld/%ld\n",
|
||
(long) stb->st_dev, (long) sta.st_dev);
|
||
if (sizeof sta.st_ino > sizeof (long))
|
||
{
|
||
dprintf(" ino = %s/",
|
||
quad_to_string(stb->st_ino));
|
||
dprintf("%s\n",
|
||
quad_to_string(sta.st_ino));
|
||
}
|
||
else
|
||
dprintf(" ino = %lu/%lu\n",
|
||
(unsigned long) stb->st_ino,
|
||
(unsigned long) sta.st_ino);
|
||
# if HAS_ST_GEN
|
||
dprintf(" gen = %ld/%ld\n",
|
||
(long) stb->st_gen, (long) sta.st_gen);
|
||
# endif /* HAS_ST_GEN */
|
||
dprintf(" uid = %ld/%ld\n",
|
||
(long) stb->st_uid, (long) sta.st_uid);
|
||
dprintf(" gid = %ld/%ld\n",
|
||
(long) stb->st_gid, (long) sta.st_gid);
|
||
}
|
||
return TRUE;
|
||
}
|
||
|
||
return FALSE;
|
||
}
|
||
/*
|
||
** DFOPEN -- determined file open
|
||
**
|
||
** This routine has the semantics of open, except that it will
|
||
** keep trying a few times to make this happen. The idea is that
|
||
** on very loaded systems, we may run out of resources (inodes,
|
||
** whatever), so this tries to get around it.
|
||
*/
|
||
|
||
int
|
||
dfopen(filename, omode, cmode, sff)
|
||
char *filename;
|
||
int omode;
|
||
int cmode;
|
||
long sff;
|
||
{
|
||
register int tries;
|
||
int fd = -1;
|
||
struct stat st;
|
||
|
||
for (tries = 0; tries < 10; tries++)
|
||
{
|
||
(void) sleep((unsigned) (10 * tries));
|
||
errno = 0;
|
||
fd = open(filename, omode, cmode);
|
||
if (fd >= 0)
|
||
break;
|
||
switch (errno)
|
||
{
|
||
case ENFILE: /* system file table full */
|
||
case EINTR: /* interrupted syscall */
|
||
#ifdef ETXTBSY
|
||
case ETXTBSY: /* Apollo: net file locked */
|
||
#endif /* ETXTBSY */
|
||
continue;
|
||
}
|
||
break;
|
||
}
|
||
if (!bitset(SFF_NOLOCK, sff) &&
|
||
fd >= 0 &&
|
||
fstat(fd, &st) >= 0 &&
|
||
S_ISREG(st.st_mode))
|
||
{
|
||
int locktype;
|
||
|
||
/* lock the file to avoid accidental conflicts */
|
||
if ((omode & O_ACCMODE) != O_RDONLY)
|
||
locktype = LOCK_EX;
|
||
else
|
||
locktype = LOCK_SH;
|
||
if (!lockfile(fd, filename, NULL, locktype))
|
||
{
|
||
int save_errno = errno;
|
||
|
||
(void) close(fd);
|
||
fd = -1;
|
||
errno = save_errno;
|
||
}
|
||
else
|
||
errno = 0;
|
||
}
|
||
return fd;
|
||
}
|