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 NULL 82 }; 83 84 struct device * 85 exec_iov2device(int type, struct physical *p, struct iovec *iov, 86 int *niov, int maxiov, int *auxfd, int *nauxfd) 87 { 88 if (type == EXEC_DEVICE) { 89 free(iov[(*niov)++].iov_base); 90 physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC); 91 return &execdevice; 92 } 93 94 return NULL; 95 } 96 97 struct device * 98 exec_Create(struct physical *p) 99 { 100 if (p->fd < 0 && *p->name.full == '!') { 101 int fids[2]; 102 103 p->fd--; /* We own the device but maybe can't use it - change fd */ 104 105 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, fids) < 0) 106 log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n", 107 strerror(errno)); 108 else { 109 int stat, argc, i; 110 pid_t pid, realpid; 111 char *argv[MAXARGS]; 112 113 stat = fcntl(fids[0], F_GETFL, 0); 114 if (stat > 0) { 115 stat |= O_NONBLOCK; 116 fcntl(fids[0], F_SETFL, stat); 117 } 118 realpid = getpid(); 119 switch ((pid = fork())) { 120 case -1: 121 log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n", 122 strerror(errno)); 123 break; 124 125 case 0: 126 close(fids[0]); 127 timer_TermService(); 128 setuid(geteuid()); 129 130 switch (fork()) { 131 case 0: 132 break; 133 134 case -1: 135 log_Printf(LogPHASE, "Unable to fork to drop parent: %s\n", 136 strerror(errno)); 137 default: 138 _exit(127); 139 } 140 141 log_Printf(LogDEBUG, "Exec'ing ``%s''\n", p->name.base); 142 143 dup2(fids[1], STDIN_FILENO); 144 dup2(fids[1], STDOUT_FILENO); 145 dup2(fids[1], STDERR_FILENO); 146 for (i = getdtablesize(); i > STDERR_FILENO; i--) 147 fcntl(i, F_SETFD, 1); 148 149 argc = MakeArgs(p->name.base, argv, VECSIZE(argv)); 150 command_Expand(argv, argc, (char const *const *)argv, 151 p->dl->bundle, 0, realpid); 152 execvp(*argv, argv); 153 printf("execvp failed: %s: %s\r\n", *argv, strerror(errno)); 154 _exit(127); 155 break; 156 157 default: 158 close(fids[1]); 159 p->fd = fids[0]; 160 waitpid(pid, &stat, 0); 161 log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd); 162 physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC); 163 return &execdevice; 164 } 165 } 166 } 167 168 return NULL; 169 } 170