exec.c revision 46686 
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 *	$Id:$
27 */
28
29#include <sys/param.h>
30#include <sys/socket.h>
31#include <netinet/in.h>
32#include <arpa/inet.h>
33#include <netdb.h>
34#include <netinet/in_systm.h>
35#include <netinet/ip.h>
36#include <sys/un.h>
37
38#include <errno.h>
39#include <fcntl.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <sys/wait.h>
44#include <termios.h>
45#include <unistd.h>
46
47#include "layer.h"
48#include "defs.h"
49#include "mbuf.h"
50#include "log.h"
51#include "sync.h"
52#include "timer.h"
53#include "lqr.h"
54#include "hdlc.h"
55#include "throughput.h"
56#include "fsm.h"
57#include "lcp.h"
58#include "ccp.h"
59#include "link.h"
60#include "async.h"
61#include "slcompress.h"
62#include "iplist.h"
63#include "ipcp.h"
64#include "filter.h"
65#include "descriptor.h"
66#include "physical.h"
67#include "mp.h"
68#ifndef NORADIUS
69#include "radius.h"
70#endif
71#include "chat.h"
72#include "command.h"
73#include "bundle.h"
74#include "prompt.h"
75#include "auth.h"
76#include "chap.h"
77#include "cbcp.h"
78#include "datalink.h"
79#include "exec.h"
80
81static int
82exec_Open(struct physical *p)
83{
84  if (*p->name.full == '!') {
85    int fids[2];
86
87    if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, fids) < 0)
88      log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
89	         strerror(errno));
90    else {
91      int stat, argc;
92      pid_t pid;
93      char *argv[MAXARGS];
94
95      stat = fcntl(fids[0], F_GETFL, 0);
96      if (stat > 0) {
97        stat |= O_NONBLOCK;
98        fcntl(fids[0], F_SETFL, stat);
99      }
100      switch ((pid = fork())) {
101        case -1:
102          log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
103	             strerror(errno));
104          break;
105
106        case  0:
107          close(fids[0]);
108          timer_TermService();
109          setuid(geteuid());
110
111          switch (fork()) {
112            case 0:
113              break;
114
115            case -1:
116              log_Printf(LogPHASE, "Unable to fork to drop parent: %s\n",
117	                 strerror(errno));
118            default:
119              _exit(127);
120          }
121
122          fids[1] = fcntl(fids[1], F_DUPFD, 3);
123          dup2(fids[1], STDIN_FILENO);
124          dup2(fids[1], STDOUT_FILENO);
125          dup2(fids[1], STDERR_FILENO);
126
127          argc = MakeArgs(p->name.base, argv, VECSIZE(argv));
128          command_Expand(argv, argc, (char const *const *)argv,
129                         p->dl->bundle, 0);
130          execvp(*argv, argv);
131          fprintf(stderr, "execvp failed: %s: %s\r\n", *argv, strerror(errno));
132          _exit(127);
133          break;
134
135        default:
136          close(fids[1]);
137          p->fd = fids[0];
138          waitpid(pid, &stat, 0);
139          log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd);
140          physical_SetupStack(p, 1);
141          return 1;
142      }
143    }
144  }
145
146  return 0;
147}
148
149const struct device execdevice = {
150  EXEC_DEVICE,
151  "exec",
152  exec_Open,
153  NULL,
154  NULL,
155  NULL,
156  NULL,
157  NULL,
158  NULL,
159  NULL
160};
161