2 Unix SMB/CIFS implementation.
3 run a command as a specified user
4 Copyright (C) Andrew Tridgell 1992-1998
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 /* need to move this from here!! need some sleep ... */
24 struct current_user current_user;
26 /****************************************************************************
27 This is a utility function of smbrun().
28 ****************************************************************************/
30 static int setup_out_fd(void)
35 slprintf(path, sizeof(path)-1, "%s/smb.XXXXXX", tmpdir());
37 /* now create the file */
38 fd = smb_mkstemp(path);
41 DEBUG(0,("setup_out_fd: Failed to create file %s. (%s)\n",
42 path, strerror(errno) ));
46 DEBUG(10,("setup_out_fd: Created tmp file %s\n", path ));
48 /* Ensure file only kept around by open fd. */
53 /****************************************************************************
54 run a command being careful about uid/gid handling and putting the output in
55 outfd (or discard it if outfd is NULL).
56 ****************************************************************************/
58 int smbrun(const char *cmd, int *outfd)
61 uid_t uid = current_user.ut.uid;
62 gid_t gid = current_user.ut.gid;
65 * Lose any kernel oplock capabilities we may have.
67 drop_effective_capability(KERNEL_OPLOCK_CAPABILITY);
69 /* point our stdout at the file we want output to go into */
71 if (outfd && ((*outfd = setup_out_fd()) == -1)) {
75 /* in this method we will exec /bin/sh with the correct
76 arguments, after first setting stdout to point at the file */
79 * We need to temporarily stop CatchChild from eating
80 * SIGCLD signals as it also eats the exit status code. JRA.
83 CatchChildLeaveStatus();
85 if ((pid=sys_fork()) < 0) {
86 DEBUG(0,("smbrun: fork failed with error %s\n", strerror(errno) ));
103 /* the parent just waits for the child to exit */
104 while((wpid = sys_waitpid(pid,&status,0)) < 0) {
115 DEBUG(2,("waitpid(%d) : %s\n",(int)pid,strerror(errno)));
123 /* Reset the seek pointer. */
125 sys_lseek(*outfd, 0, SEEK_SET);
128 #if defined(WIFEXITED) && defined(WEXITSTATUS)
129 if (WIFEXITED(status)) {
130 return WEXITSTATUS(status);
139 /* we are in the child. we exec /bin/sh to do the work for us. we
140 don't directly exec the command we want because it may be a
141 pipeline or anything else the config file specifies */
143 /* point our stdout at the file we want output to go into */
146 if (sys_dup2(*outfd,1) != 1) {
147 DEBUG(2,("Failed to create stdout file descriptor\n"));
153 /* now completely lose our privileges. This is a fairly paranoid
154 way of doing it, but it does work on all systems that I know of */
156 become_user_permanently(uid, gid);
158 if (getuid() != uid || geteuid() != uid ||
159 getgid() != gid || getegid() != gid) {
160 /* we failed to lose our privileges - do not execute
162 exit(81); /* we can't print stuff at this stage,
163 instead use exit codes for debugging */
167 /* close all other file descriptors, leaving only 0, 1 and 2. 0 and
168 2 point to /dev/null from the startup code */
171 for (fd=3;fd<256;fd++) close(fd);
175 execl("/bin/sh","sh","-c",cmd,NULL);
183 /****************************************************************************
184 run a command being careful about uid/gid handling and putting the output in
185 outfd (or discard it if outfd is NULL).
186 sends the provided secret to the child stdin.
187 ****************************************************************************/
189 int smbrunsecret(const char *cmd, const char *secret)
192 uid_t uid = current_user.ut.uid;
193 gid_t gid = current_user.ut.gid;
197 * Lose any kernel oplock capabilities we may have.
199 drop_effective_capability(KERNEL_OPLOCK_CAPABILITY);
201 /* build up an input pipe */
206 /* in this method we will exec /bin/sh with the correct
207 arguments, after first setting stdout to point at the file */
210 * We need to temporarily stop CatchChild from eating
211 * SIGCLD signals as it also eats the exit status code. JRA.
214 CatchChildLeaveStatus();
216 if ((pid=sys_fork()) < 0) {
217 DEBUG(0, ("smbrunsecret: fork failed with error %s\n", strerror(errno)));
232 /* send the secret */
233 towrite = strlen(secret);
234 wrote = write(ifd[1], secret, towrite);
235 if ( wrote != towrite ) {
236 DEBUG(0,("smbrunsecret: wrote %ld of %lu bytes\n",(long)wrote,(unsigned long)towrite));
241 /* the parent just waits for the child to exit */
242 while((wpid = sys_waitpid(pid, &status, 0)) < 0) {
253 DEBUG(2, ("waitpid(%d) : %s\n", (int)pid, strerror(errno)));
257 #if defined(WIFEXITED) && defined(WEXITSTATUS)
258 if (WIFEXITED(status)) {
259 return WEXITSTATUS(status);
268 /* we are in the child. we exec /bin/sh to do the work for us. we
269 don't directly exec the command we want because it may be a
270 pipeline or anything else the config file specifies */
274 if (sys_dup2(ifd[0], 0) != 0) {
275 DEBUG(2,("Failed to create stdin file descriptor\n"));
280 /* now completely lose our privileges. This is a fairly paranoid
281 way of doing it, but it does work on all systems that I know of */
283 become_user_permanently(uid, gid);
285 if (getuid() != uid || geteuid() != uid ||
286 getgid() != gid || getegid() != gid) {
287 /* we failed to lose our privileges - do not execute
289 exit(81); /* we can't print stuff at this stage,
290 instead use exit codes for debugging */
294 /* close all other file descriptors, leaving only 0, 1 and 2. 0 and
295 2 point to /dev/null from the startup code */
298 for (fd = 3; fd < 256; fd++) close(fd);
302 execl("/bin/sh", "sh", "-c", cmd, NULL);