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 <sys/types.h> 19 #include <sys/time.h> 20 #include <sys/resource.h> 21 22 #include <errno.h> 23 #include <stdarg.h> 24 #include <stdio.h> 25 #include <stdlib.h> 26 #include <string.h> 27 #include <unistd.h> 28 29 #include "log.h" 30 #include "ssh-sandbox.h" 31 #include "xmalloc.h" 32 33 /* Minimal sandbox that sets zero nfiles, nprocs and filesize rlimits */ 34 35 struct ssh_sandbox { 36 pid_t child_pid; 37 }; 38 39 struct ssh_sandbox * 40 ssh_sandbox_init(void) 41 { 42 struct ssh_sandbox *box; 43 44 /* 45 * Strictly, we don't need to maintain any state here but we need 46 * to return non-NULL to satisfy the API. 47 */ 48 debug3_f("preparing rlimit sandbox"); 49 box = xcalloc(1, sizeof(*box)); 50 box->child_pid = 0; 51 52 return box; 53 } 54 55 void 56 ssh_sandbox_child(struct ssh_sandbox *box) 57 { 58 struct rlimit rl_zero; 59 60 rl_zero.rlim_cur = rl_zero.rlim_max = 0; 61 62 if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1) 63 fatal_f("setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s", 64 strerror(errno)); 65 if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1) 66 fatal_f("setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s", 67 strerror(errno)); 68 if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1) 69 fatal_f("setrlimit(RLIMIT_NPROC, { 0, 0 }): %s", 70 strerror(errno)); 71 } 72 73 void 74 ssh_sandbox_parent_finish(struct ssh_sandbox *box) 75 { 76 free(box); 77 debug3_f("finished"); 78 } 79 80 void 81 ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid) 82 { 83 box->child_pid = child_pid; 84 /* Nothing to do here */ 85 } 86 87