1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
Unix SMB/Netbios implementation.
Version 1.9.
run a command as a specified user
Copyright (C) Andrew Tridgell 1992-1998
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/* need to move this from here!! need some sleep ... */
struct current_user current_user;
/****************************************************************************
This is a utility function of smbrun().
****************************************************************************/
static int setup_out_fd(void)
{
int fd;
pstring path;
slprintf(path, sizeof(path)-1, "%s/smb.XXXXXX", tmpdir());
/* now create the file */
fd = smb_mkstemp(path);
if (fd == -1) {
DEBUG(0,("setup_out_fd: Failed to create file %s. (%s)\n",
path, strerror(errno) ));
return -1;
}
DEBUG(10,("setup_out_fd: Created tmp file %s\n", path ));
/* Ensure file only kept around by open fd. */
unlink(path);
return fd;
}
/****************************************************************************
run a command being careful about uid/gid handling and putting the output in
outfd (or discard it if outfd is NULL).
****************************************************************************/
int smbrun(char *cmd, int *outfd)
{
pid_t pid;
uid_t uid = current_user.uid;
gid_t gid = current_user.gid;
/*
* Lose any kernel oplock capabilities we may have.
*/
oplock_set_capability(False, False);
/* point our stdout at the file we want output to go into */
if (outfd && ((*outfd = setup_out_fd()) == -1)) {
return -1;
}
/* in this method we will exec /bin/sh with the correct
arguments, after first setting stdout to point at the file */
/*
* We need to temporarily stop CatchChild from eating
* SIGCLD signals as it also eats the exit status code. JRA.
*/
CatchChildLeaveStatus();
if ((pid=sys_fork()) < 0) {
DEBUG(0,("smbrun: fork failed with error %s\n", strerror(errno) ));
CatchChild();
if (outfd) {
close(*outfd);
*outfd = -1;
}
return errno;
}
if (pid) {
/*
* Parent.
*/
int status=0;
pid_t wpid;
/* the parent just waits for the child to exit */
while((wpid = sys_waitpid(pid,&status,0)) < 0) {
if(errno == EINTR) {
errno = 0;
continue;
}
break;
}
CatchChild();
if (wpid != pid) {
DEBUG(2,("waitpid(%d) : %s\n",(int)pid,strerror(errno)));
if (outfd) {
close(*outfd);
*outfd = -1;
}
return -1;
}
/* Reset the seek pointer. */
if (outfd) {
sys_lseek(*outfd, 0, SEEK_SET);
}
#if defined(WIFEXITED) && defined(WEXITSTATUS)
if (WIFEXITED(status)) {
return WEXITSTATUS(status);
}
#endif
return status;
}
CatchChild();
/* we are in the child. we exec /bin/sh to do the work for us. we
don't directly exec the command we want because it may be a
pipeline or anything else the config file specifies */
/* point our stdout at the file we want output to go into */
if (outfd) {
close(1);
if (dup2(*outfd,1) != 1) {
DEBUG(2,("Failed to create stdout file descriptor\n"));
close(*outfd);
exit(80);
}
}
/* now completely lose our privileges. This is a fairly paranoid
way of doing it, but it does work on all systems that I know of */
become_user_permanently(uid, gid);
if (getuid() != uid || geteuid() != uid ||
getgid() != gid || getegid() != gid) {
/* we failed to lose our privileges - do not execute
the command */
exit(81); /* we can't print stuff at this stage,
instead use exit codes for debugging */
}
#ifndef __INSURE__
/* close all other file descriptors, leaving only 0, 1 and 2. 0 and
2 point to /dev/null from the startup code */
{
int fd;
for (fd=3;fd<256;fd++) close(fd);
}
#endif
execl("/bin/sh","sh","-c",cmd,NULL);
/* not reached */
exit(82);
return 1;
}
|
