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: src/usr.sbin/ppp/exec.c,v 1.18.2.6 2002/09/01 02:12:26 brian Exp $ 27 * $DragonFly: src/usr.sbin/ppp/exec.c,v 1.2 2003/06/17 04:30:00 dillon Exp $ 28 */ 29 30 #include <sys/param.h> 31 #include <sys/socket.h> 32 #include <sys/un.h> 33 34 #include <errno.h> 35 #include <fcntl.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <sys/wait.h> 40 #include <sys/uio.h> 41 #include <termios.h> 42 #include <unistd.h> 43 44 #include "layer.h" 45 #include "defs.h" 46 #include "mbuf.h" 47 #include "log.h" 48 #include "timer.h" 49 #include "lqr.h" 50 #include "hdlc.h" 51 #include "throughput.h" 52 #include "fsm.h" 53 #include "lcp.h" 54 #include "ccp.h" 55 #include "link.h" 56 #include "async.h" 57 #include "descriptor.h" 58 #include "physical.h" 59 #include "mp.h" 60 #include "chat.h" 61 #include "command.h" 62 #include "auth.h" 63 #include "chap.h" 64 #include "cbcp.h" 65 #include "datalink.h" 66 #include "id.h" 67 #include "exec.h" 68 69 static struct device execdevice = { 70 EXEC_DEVICE, 71 "exec", 72 0, 73 { CD_NOTREQUIRED, 0 }, 74 NULL, 75 NULL, 76 NULL, 77 NULL, 78 NULL, 79 NULL, 80 NULL, 81 NULL, 82 NULL, 83 NULL, 84 NULL, 85 NULL, 86 NULL, 87 NULL 88 }; 89 90 struct device * 91 exec_iov2device(int type, struct physical *p, struct iovec *iov, 92 int *niov, int maxiov __unused, int *auxfd __unused, 93 int *nauxfd __unused) 94 { 95 if (type == EXEC_DEVICE) { 96 free(iov[(*niov)++].iov_base); 97 physical_SetupStack(p, execdevice.name, PHYSICAL_NOFORCE); 98 return &execdevice; 99 } 100 101 return NULL; 102 } 103 104 struct device * 105 exec_Create(struct physical *p) 106 { 107 if (p->fd < 0 && *p->name.full == '!') { 108 int fids[2], type; 109 110 p->fd--; /* We own the device but maybe can't use it - change fd */ 111 type = physical_IsSync(p) ? SOCK_DGRAM : SOCK_STREAM; 112 113 if (socketpair(AF_UNIX, type, PF_UNSPEC, fids) < 0) 114 log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n", 115 strerror(errno)); 116 else { 117 static int child_status; /* This variable is abused ! */ 118 int stat, argc, i, ret, wret, pidpipe[2]; 119 pid_t pid, realpid; 120 char *argv[MAXARGS]; 121 122 stat = fcntl(fids[0], F_GETFL, 0); 123 if (stat > 0) { 124 stat |= O_NONBLOCK; 125 fcntl(fids[0], F_SETFL, stat); 126 } 127 realpid = getpid(); 128 if (pipe(pidpipe) == -1) { 129 log_Printf(LogPHASE, "Unable to pipe for line exec: %s\n", 130 strerror(errno)); 131 close(fids[1]); 132 } else switch ((pid = fork())) { 133 case -1: 134 log_Printf(LogPHASE, "Unable to fork for line exec: %s\n", 135 strerror(errno)); 136 close(pidpipe[0]); 137 close(pidpipe[1]); 138 close(fids[1]); 139 break; 140 141 case 0: 142 close(pidpipe[0]); 143 close(fids[0]); 144 timer_TermService(); 145 #ifndef NOSUID 146 setuid(ID0realuid()); 147 #endif 148 149 child_status = 0; 150 switch ((pid = vfork())) { 151 case 0: 152 close(pidpipe[1]); 153 break; 154 155 case -1: 156 ret = errno; 157 log_Printf(LogPHASE, "Unable to vfork to drop parent: %s\n", 158 strerror(errno)); 159 close(pidpipe[1]); 160 _exit(ret); 161 162 default: 163 write(pidpipe[1], &pid, sizeof pid); 164 close(pidpipe[1]); 165 _exit(child_status); /* The error from exec() ! */ 166 } 167 168 log_Printf(LogDEBUG, "Exec'ing ``%s''\n", p->name.base); 169 170 if ((argc = MakeArgs(p->name.base, argv, VECSIZE(argv), 171 PARSE_REDUCE|PARSE_NOHASH)) < 0) { 172 log_Printf(LogWARN, "Syntax error in exec command\n"); 173 _exit(ESRCH); 174 } 175 176 command_Expand(argv, argc, (char const *const *)argv, 177 p->dl->bundle, 0, realpid); 178 179 dup2(fids[1], STDIN_FILENO); 180 dup2(fids[1], STDOUT_FILENO); 181 dup2(fids[1], STDERR_FILENO); 182 for (i = getdtablesize(); i > STDERR_FILENO; i--) 183 fcntl(i, F_SETFD, 1); 184 185 execvp(*argv, argv); 186 child_status = errno; /* Only works for vfork() */ 187 printf("execvp failed: %s: %s\r\n", *argv, strerror(child_status)); 188 _exit(child_status); 189 break; 190 191 default: 192 close(pidpipe[1]); 193 close(fids[1]); 194 if (read(pidpipe[0], &p->session_owner, sizeof p->session_owner) != 195 sizeof p->session_owner) 196 p->session_owner = (pid_t)-1; 197 close(pidpipe[0]); 198 while ((wret = waitpid(pid, &stat, 0)) == -1 && errno == EINTR) 199 ; 200 if (wret == -1) { 201 log_Printf(LogWARN, "Waiting for child process: %s\n", 202 strerror(errno)); 203 close(fids[0]); 204 p->session_owner = (pid_t)-1; 205 break; 206 } else if (WIFSIGNALED(stat)) { 207 log_Printf(LogWARN, "Child process received sig %d !\n", 208 WTERMSIG(stat)); 209 close(fids[0]); 210 p->session_owner = (pid_t)-1; 211 break; 212 } else if (WIFSTOPPED(stat)) { 213 log_Printf(LogWARN, "Child process received stop sig %d !\n", 214 WSTOPSIG(stat)); 215 /* I guess that's ok.... */ 216 } else if ((ret = WEXITSTATUS(stat))) { 217 log_Printf(LogWARN, "Cannot exec \"%s\": %s\n", p->name.base, 218 strerror(ret)); 219 close(fids[0]); 220 p->session_owner = (pid_t)-1; 221 break; 222 } 223 p->fd = fids[0]; 224 log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd); 225 physical_SetupStack(p, execdevice.name, PHYSICAL_NOFORCE); 226 if (p->cfg.cd.necessity != CD_DEFAULT) 227 log_Printf(LogWARN, "Carrier settings ignored\n"); 228 return &execdevice; 229 } 230 close(fids[0]); 231 } 232 } 233 234 return NULL; 235 } 236