exec.c revision 50479 
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: head/usr.sbin/ppp/exec.c 50479 1999-08-28 01:35:59Z peter $
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
67static 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};
82
83struct device *
84exec_iov2device(int type, struct physical *p, struct iovec *iov,
85                int *niov, int maxiov)
86{
87  if (type == EXEC_DEVICE) {
88    free(iov[(*niov)++].iov_base);
89    physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC);
90    return &execdevice;
91  }
92
93  return NULL;
94}
95
96struct device *
97exec_Create(struct physical *p)
98{
99  if (p->fd < 0 && *p->name.full == '!') {
100    int fids[2];
101
102    if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, fids) < 0)
103      log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
104	         strerror(errno));
105    else {
106      int stat, argc, i;
107      pid_t pid, realpid;
108      char *argv[MAXARGS];
109
110      stat = fcntl(fids[0], F_GETFL, 0);
111      if (stat > 0) {
112        stat |= O_NONBLOCK;
113        fcntl(fids[0], F_SETFL, stat);
114      }
115      realpid = getpid();
116      switch ((pid = fork())) {
117        case -1:
118          log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n",
119	             strerror(errno));
120          break;
121
122        case  0:
123          close(fids[0]);
124          timer_TermService();
125          setuid(geteuid());
126
127          switch (fork()) {
128            case 0:
129              break;
130
131            case -1:
132              log_Printf(LogPHASE, "Unable to fork to drop parent: %s\n",
133	                 strerror(errno));
134            default:
135              _exit(127);
136          }
137
138          log_Printf(LogDEBUG, "Exec'ing ``%s''\n", p->name.base);
139
140          dup2(fids[1], STDIN_FILENO);
141          dup2(fids[1], STDOUT_FILENO);
142          dup2(fids[1], STDERR_FILENO);
143          for (i = getdtablesize(); i > STDERR_FILENO; i--)
144            fcntl(i, F_SETFD, 1);
145
146          argc = MakeArgs(p->name.base, argv, VECSIZE(argv));
147          command_Expand(argv, argc, (char const *const *)argv,
148                         p->dl->bundle, 0, realpid);
149          execvp(*argv, argv);
150          printf("execvp failed: %s: %s\r\n", *argv, strerror(errno));
151          _exit(127);
152          break;
153
154        default:
155          close(fids[1]);
156          p->fd = fids[0];
157          waitpid(pid, &stat, 0);
158          log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd);
159          physical_SetupStack(p, execdevice.name, PHYSICAL_FORCE_ASYNC);
160          return &execdevice;
161      }
162    }
163  }
164
165  return NULL;
166}
167