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Diffstat (limited to 'source/lib/smbrun.c')
| -rw-r--r-- | source/lib/smbrun.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/source/lib/smbrun.c b/source/lib/smbrun.c new file mode 100644 index 00000000000..1ace6e3a991 --- /dev/null +++ b/source/lib/smbrun.c @@ -0,0 +1,181 @@ +/* + 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; +} |