1 /* $OpenBSD: sandbox-rlimit.c,v 1.5 2020/10/18 11:32:01 djm Exp $ */ 2 /* 3 * Copyright (c) 2011 Damien Miller <djm@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/time.h> 24 #include <sys/resource.h> 25 26 #include <errno.h> 27 #include <stdarg.h> 28 #include <stdio.h> 29 #include <stdlib.h> 30 #include <string.h> 31 #include <unistd.h> 32 33 #include "log.h" 34 #include "ssh-sandbox.h" 35 #include "xmalloc.h" 36 37 /* Minimal sandbox that sets zero nfiles, nprocs and filesize rlimits */ 38 39 struct ssh_sandbox { 40 pid_t child_pid; 41 }; 42 43 struct ssh_sandbox * 44 ssh_sandbox_init(struct monitor *monitor) 45 { 46 struct ssh_sandbox *box; 47 48 /* 49 * Strictly, we don't need to maintain any state here but we need 50 * to return non-NULL to satisfy the API. 51 */ 52 debug3_f("preparing rlimit sandbox"); 53 box = xcalloc(1, sizeof(*box)); 54 box->child_pid = 0; 55 56 return box; 57 } 58 59 void 60 ssh_sandbox_child(struct ssh_sandbox *box) 61 { 62 struct rlimit rl_zero; 63 64 rl_zero.rlim_cur = rl_zero.rlim_max = 0; 65 66 #ifndef SANDBOX_SKIP_RLIMIT_FSIZE 67 if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1) 68 fatal_f("setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s", 69 strerror(errno)); 70 #endif 71 #ifndef SANDBOX_SKIP_RLIMIT_NOFILE 72 if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1) 73 fatal_f("setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s", 74 strerror(errno)); 75 #endif 76 #ifdef HAVE_RLIMIT_NPROC 77 if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1) 78 fatal_f("setrlimit(RLIMIT_NPROC, { 0, 0 }): %s", 79 strerror(errno)); 80 #endif 81 } 82 83 void 84 ssh_sandbox_parent_finish(struct ssh_sandbox *box) 85 { 86 free(box); 87 debug3_f("finished"); 88 } 89 90 void 91 ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid) 92 { 93 box->child_pid = child_pid; 94 } 95 96 #endif /* SANDBOX_RLIMIT */ 97