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author | Jelmer Vernooij <jelmer@samba.org> | 2008-10-21 14:51:13 +0200 |
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committer | Jelmer Vernooij <jelmer@samba.org> | 2008-10-21 14:51:13 +0200 |
commit | 5209a846a9157e649fcdcb561f7eaf19c8c0e465 (patch) | |
tree | b0a7e52b5646c8eec182dbc391e7934b6804488c /lib/util/unix_privs.c | |
parent | 625359b2e266105022309df8985720108ecd6f67 (diff) | |
parent | 2ee8d29d22bcb1c350ab59d71b0aee548489bc9c (diff) | |
download | samba-5209a846a9157e649fcdcb561f7eaf19c8c0e465.tar.gz samba-5209a846a9157e649fcdcb561f7eaf19c8c0e465.tar.bz2 samba-5209a846a9157e649fcdcb561f7eaf19c8c0e465.zip |
Merge branch 'master' of ssh://git.samba.org/data/git/samba into regsrv
Conflicts:
source4/lib/registry/ldb.c
source4/rpc_server/winreg/rpc_winreg.c
Diffstat (limited to 'lib/util/unix_privs.c')
-rw-r--r-- | lib/util/unix_privs.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/lib/util/unix_privs.c b/lib/util/unix_privs.c new file mode 100644 index 0000000000..f55e739a9b --- /dev/null +++ b/lib/util/unix_privs.c @@ -0,0 +1,78 @@ +/* + Unix SMB/CIFS implementation. + + gain/lose root privileges + + Copyright (C) Andrew Tridgell 2004 + + This program 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 3 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 this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "system/filesys.h" +#include "../lib/util/unix_privs.h" + +/** + * @file + * @brief Gaining/losing root privileges + */ + +/* + there are times when smbd needs to temporarily gain root privileges + to do some operation. To do this you call root_privileges(), which + returns a talloc handle. To restore your previous privileges + talloc_free() this pointer. + + Note that this call is considered successful even if it does not + manage to gain root privileges, but it will call smb_abort() if it + fails to restore the privileges afterwards. The logic is that + failing to gain root access can be caught by whatever operation + needs to be run as root failing, but failing to lose the root + privileges is dangerous. + + This also means that this code is safe to be called from completely + unprivileged processes. +*/ + +struct saved_state { + uid_t uid; +}; + +static int privileges_destructor(struct saved_state *s) +{ + if (geteuid() != s->uid && + seteuid(s->uid) != 0) { + smb_panic("Failed to restore privileges"); + } + return 0; +} + +/** + * Obtain root privileges for the current process. + * + * The privileges can be dropped by talloc_free()-ing the + * token returned by this function + */ +void *root_privileges(void) +{ + struct saved_state *s; + s = talloc(NULL, struct saved_state); + if (!s) return NULL; + s->uid = geteuid(); + if (s->uid != 0) { + seteuid(0); + } + talloc_set_destructor(s, privileges_destructor); + return s; +} |