1 /*- 2 * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/socket.h> 31 #include <sys/un.h> 32 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <stdio.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <sys/wait.h> 39 #include <sys/uio.h> 40 #include <termios.h> 41 #include <unistd.h> 42 43 #include "layer.h" 44 #include "defs.h" 45 #include "mbuf.h" 46 #include "log.h" 47 #include "timer.h" 48 #include "lqr.h" 49 #include "hdlc.h" 50 #include "throughput.h" 51 #include "fsm.h" 52 #include "lcp.h" 53 #include "ccp.h" 54 #include "link.h" 55 #include "async.h" 56 #include "descriptor.h" 57 #include "physical.h" 58 #include "mp.h" 59 #include "chat.h" 60 #include "command.h" 61 #include "auth.h" 62 #include "chap.h" 63 #include "cbcp.h" 64 #include "datalink.h" 65 #include "exec.h" 66 67 static struct device execdevice = { 68 EXEC_DEVICE, 69 "exec", 70 NULL, 71 NULL, 72 NULL, 73 NULL, 74 NULL, 75 NULL, 76 NULL, 77 NULL, 78 NULL, 79 NULL, 80 NULL 81 }; 82 83 struct device * 84 exec_iov2device(int type, struct physical *p, struct iovec *iov, 85 int *niov, int maxiov) 86 { 87 if (type == EXEC_DEVICE) { 88 free(iov[(*niov)++].iov_base); 89 physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC); 90 return &execdevice; 91 } 92 93 return NULL; 94 } 95 96 struct device * 97 exec_Create(struct physical *p) 98 { 99 if (p->fd < 0 && *p->name.full == '!') { 100 int fids[2]; 101 102 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, fids) < 0) 103 log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n", 104 strerror(errno)); 105 else { 106 int stat, argc, i; 107 pid_t pid, realpid; 108 char *argv[MAXARGS]; 109 110 stat = fcntl(fids[0], F_GETFL, 0); 111 if (stat > 0) { 112 stat |= O_NONBLOCK; 113 fcntl(fids[0], F_SETFL, stat); 114 } 115 realpid = getpid(); 116 switch ((pid = fork())) { 117 case -1: 118 log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n", 119 strerror(errno)); 120 break; 121 122 case 0: 123 close(fids[0]); 124 timer_TermService(); 125 setuid(geteuid()); 126 127 switch (fork()) { 128 case 0: 129 break; 130 131 case -1: 132 log_Printf(LogPHASE, "Unable to fork to drop parent: %s\n", 133 strerror(errno)); 134 default: 135 _exit(127); 136 } 137 138 log_Printf(LogDEBUG, "Exec'ing ``%s''\n", p->name.base); 139 140 dup2(fids[1], STDIN_FILENO); 141 dup2(fids[1], STDOUT_FILENO); 142 dup2(fids[1], STDERR_FILENO); 143 for (i = getdtablesize(); i > STDERR_FILENO; i--) 144 fcntl(i, F_SETFD, 1); 145 146 argc = MakeArgs(p->name.base, argv, VECSIZE(argv)); 147 command_Expand(argv, argc, (char const *const *)argv, 148 p->dl->bundle, 0, realpid); 149 execvp(*argv, argv); 150 printf("execvp failed: %s: %s\r\n", *argv, strerror(errno)); 151 _exit(127); 152 break; 153 154 default: 155 close(fids[1]); 156 p->fd = fids[0]; 157 waitpid(pid, &stat, 0); 158 log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd); 159 physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC); 160 return &execdevice; 161 } 162 } 163 } 164 165 return NULL; 166 } 167