exec.c revision 47769 
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 1.4 1999/06/01 19:08:57 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 <sys/uio.h>
45#include <termios.h>
46#include <unistd.h>
47
48#include "layer.h"
49#include "defs.h"
50#include "mbuf.h"
51#include "log.h"
52#include "sync.h"
53#include "timer.h"
54#include "lqr.h"
55#include "hdlc.h"
56#include "throughput.h"
57#include "fsm.h"
58#include "lcp.h"
59#include "ccp.h"
60#include "link.h"
61#include "async.h"
62#include "slcompress.h"
63#include "iplist.h"
64#include "ipcp.h"
65#include "filter.h"
66#include "descriptor.h"
67#include "physical.h"
68#include "mp.h"
69#ifndef NORADIUS
70#include "radius.h"
71#endif
72#include "chat.h"
73#include "command.h"
74#include "bundle.h"
75#include "prompt.h"
76#include "auth.h"
77#include "chap.h"
78#include "cbcp.h"
79#include "datalink.h"
80#include "exec.h"
81
82static struct device execdevice = {
83  EXEC_DEVICE,
84  "exec",
85  NULL,
86  NULL,
87  NULL,
88  NULL,
89  NULL,
90  NULL,
91  NULL,
92  NULL,
93  NULL,
94  NULL
95};
96
97struct device *
98exec_iov2device(int type, struct physical *p, struct iovec *iov,
99                int *niov, int maxiov)
100{
101  if (type == EXEC_DEVICE) {
102    free(iov[(*niov)++].iov_base);
103    physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC);
104    return &execdevice;
105  }
106
107  return NULL;
108}
109
110struct device *
111exec_Create(struct physical *p)
112{
113  if (p->fd < 0 && *p->name.full == '!') {
114    int fids[2];
115
116    if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, fids) < 0)
117      log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
118	         strerror(errno));
119    else {
120      int stat, argc;
121      pid_t pid;
122      char *argv[MAXARGS];
123
124      stat = fcntl(fids[0], F_GETFL, 0);
125      if (stat > 0) {
126        stat |= O_NONBLOCK;
127        fcntl(fids[0], F_SETFL, stat);
128      }
129      switch ((pid = fork())) {
130        case -1:
131          log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
132	             strerror(errno));
133          break;
134
135        case  0:
136          close(fids[0]);
137          timer_TermService();
138          setuid(geteuid());
139
140          switch (fork()) {
141            case 0:
142              break;
143
144            case -1:
145              log_Printf(LogPHASE, "Unable to fork to drop parent: %s\n",
146	                 strerror(errno));
147            default:
148              _exit(127);
149          }
150
151          fids[1] = fcntl(fids[1], F_DUPFD, 3);
152          dup2(fids[1], STDIN_FILENO);
153          dup2(fids[1], STDOUT_FILENO);
154          dup2(fids[1], STDERR_FILENO);
155
156          log_Printf(LogDEBUG, "Exec'ing ``%s''\n", p->name.base);
157          argc = MakeArgs(p->name.base, argv, VECSIZE(argv));
158          command_Expand(argv, argc, (char const *const *)argv,
159                         p->dl->bundle, 0);
160          execvp(*argv, argv);
161          fprintf(stderr, "execvp failed: %s: %s\r\n", *argv, strerror(errno));
162          _exit(127);
163          break;
164
165        default:
166          close(fids[1]);
167          p->fd = fids[0];
168          waitpid(pid, &stat, 0);
169          log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd);
170          physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC);
171          return &execdevice;
172      }
173    }
174  }
175
176  return NULL;
177}
178