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-rw-r--r--source3/lib/smbrun.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/source3/lib/smbrun.c b/source3/lib/smbrun.c
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+++ b/source3/lib/smbrun.c
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+/*
+ Unix SMB/CIFS implementation.
+ 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;
+}