exec.c revision 47461 
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: exec.c,v 1.2 1999/05/12 09:48:49 brian Exp $
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 struct device execdevice = {
82  EXEC_DEVICE,
83  "exec",
84  NULL,
85  NULL,
86  NULL,
87  NULL,
88  NULL,
89  NULL,
90  NULL,
91  NULL,
92  NULL,
93  NULL
94};
95
96struct device *
97exec_iov2device(int type, struct physical *p, struct iovec *iov,
98                int *niov, int maxiov)
99{
100  if (type == EXEC_DEVICE) {
101    physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC);
102    return &execdevice;
103  }
104
105  return NULL;
106}
107
108struct device *
109exec_Create(struct physical *p)
110{
111  if (p->fd < 0 && *p->name.full == '!') {
112    int fids[2];
113
114    if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, fids) < 0)
115      log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
116	         strerror(errno));
117    else {
118      int stat, argc;
119      pid_t pid;
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      switch ((pid = fork())) {
128        case -1:
129          log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
130	             strerror(errno));
131          break;
132
133        case  0:
134          close(fids[0]);
135          timer_TermService();
136          setuid(geteuid());
137
138          switch (fork()) {
139            case 0:
140              break;
141
142            case -1:
143              log_Printf(LogPHASE, "Unable to fork to drop parent: %s\n",
144	                 strerror(errno));
145            default:
146              _exit(127);
147          }
148
149          fids[1] = fcntl(fids[1], F_DUPFD, 3);
150          dup2(fids[1], STDIN_FILENO);
151          dup2(fids[1], STDOUT_FILENO);
152          dup2(fids[1], STDERR_FILENO);
153
154          argc = MakeArgs(p->name.base, argv, VECSIZE(argv));
155          command_Expand(argv, argc, (char const *const *)argv,
156                         p->dl->bundle, 0);
157          execvp(*argv, argv);
158          fprintf(stderr, "execvp failed: %s: %s\r\n", *argv, strerror(errno));
159          _exit(127);
160          break;
161
162        default:
163          close(fids[1]);
164          p->fd = fids[0];
165          waitpid(pid, &stat, 0);
166          log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd);
167          physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC);
168          return &execdevice;
169      }
170    }
171  }
172
173  return NULL;
174}
175