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      1 /* $OpenBSD: sandbox-rlimit.c,v 1.3 2011/06/23 09:34:13 djm Exp $ */
      2 /*
      3  * Copyright (c) 2011 Damien Miller <djm (at) mindrot.org>
      4  *
      5  * Permission to use, copy, modify, and distribute this software for any
      6  * purpose with or without fee is hereby granted, provided that the above
      7  * copyright notice and this permission notice appear in all copies.
      8  *
      9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     16  */
     17 
     18 #include "includes.h"
     19 
     20 #ifdef SANDBOX_RLIMIT
     21 
     22 #include <sys/types.h>
     23 #include <sys/param.h>
     24 #include <sys/time.h>
     25 #include <sys/resource.h>
     26 
     27 #include <errno.h>
     28 #include <stdarg.h>
     29 #include <stdio.h>
     30 #include <stdlib.h>
     31 #include <string.h>
     32 #include <unistd.h>
     33 
     34 #include "log.h"
     35 #include "ssh-sandbox.h"
     36 #include "xmalloc.h"
     37 
     38 /* Minimal sandbox that sets zero nfiles, nprocs and filesize rlimits */
     39 
     40 struct ssh_sandbox {
     41 	pid_t child_pid;
     42 };
     43 
     44 struct ssh_sandbox *
     45 ssh_sandbox_init(struct monitor *monitor)
     46 {
     47 	struct ssh_sandbox *box;
     48 
     49 	/*
     50 	 * Strictly, we don't need to maintain any state here but we need
     51 	 * to return non-NULL to satisfy the API.
     52 	 */
     53 	debug3("%s: preparing rlimit sandbox", __func__);
     54 	box = xcalloc(1, sizeof(*box));
     55 	box->child_pid = 0;
     56 
     57 	return box;
     58 }
     59 
     60 void
     61 ssh_sandbox_child(struct ssh_sandbox *box)
     62 {
     63 	struct rlimit rl_zero;
     64 
     65 	rl_zero.rlim_cur = rl_zero.rlim_max = 0;
     66 
     67 #ifndef SANDBOX_SKIP_RLIMIT_FSIZE
     68 	if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1)
     69 		fatal("%s: setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s",
     70 			__func__, strerror(errno));
     71 #endif
     72 #ifndef SANDBOX_SKIP_RLIMIT_NOFILE
     73 	if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1)
     74 		fatal("%s: setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s",
     75 			__func__, strerror(errno));
     76 #endif
     77 #ifdef HAVE_RLIMIT_NPROC
     78 	if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1)
     79 		fatal("%s: setrlimit(RLIMIT_NPROC, { 0, 0 }): %s",
     80 			__func__, strerror(errno));
     81 #endif
     82 }
     83 
     84 void
     85 ssh_sandbox_parent_finish(struct ssh_sandbox *box)
     86 {
     87 	free(box);
     88 	debug3("%s: finished", __func__);
     89 }
     90 
     91 void
     92 ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid)
     93 {
     94 	box->child_pid = child_pid;
     95 }
     96 
     97 #endif /* SANDBOX_RLIMIT */
     98