diff options
Diffstat (limited to 'source3/lib/pidfile.c')
| -rw-r--r-- | source3/lib/pidfile.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/source3/lib/pidfile.c b/source3/lib/pidfile.c new file mode 100644 index 0000000000..f49f8afbb6 --- /dev/null +++ b/source3/lib/pidfile.c @@ -0,0 +1,147 @@ +/* this code is broken - there is a race condition with the unlink (tridge) */ + +/* + Unix SMB/CIFS implementation. + pidfile handling + Copyright (C) Andrew Tridgell 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 3 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, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" + +#ifndef O_NONBLOCK +#define O_NONBLOCK +#endif + +/* return the pid in a pidfile. return 0 if the process (or pidfile) + does not exist */ +pid_t pidfile_pid(const char *name) +{ + int fd; + char pidstr[20]; + pid_t pid; + unsigned int ret; + char * pidFile; + + if (asprintf(&pidFile, "%s/%s.pid", lp_piddir(), name) == -1) { + return 0; + } + + fd = sys_open(pidFile, O_NONBLOCK | O_RDONLY, 0644); + if (fd == -1) { + SAFE_FREE(pidFile); + return 0; + } + + ZERO_ARRAY(pidstr); + + if (read(fd, pidstr, sizeof(pidstr)-1) <= 0) { + goto noproc; + } + + ret = atoi(pidstr); + + if (ret == 0) { + /* Obviously we had some garbage in the pidfile... */ + DEBUG(1, ("Could not parse contents of pidfile %s\n", + pidFile)); + goto noproc; + } + + pid = (pid_t)ret; + if (!process_exists_by_pid(pid)) { + goto noproc; + } + + if (fcntl_lock(fd,SMB_F_SETLK,0,1,F_RDLCK)) { + /* we could get the lock - it can't be a Samba process */ + goto noproc; + } + + SAFE_FREE(pidFile); + close(fd); + return (pid_t)ret; + + noproc: + close(fd); + unlink(pidFile); + SAFE_FREE(pidFile); + return 0; +} + +/* create a pid file in the pid directory. open it and leave it locked */ +void pidfile_create(const char *program_name) +{ + int fd; + char buf[20]; + const char *short_configfile; + char *name; + char *pidFile; + pid_t pid; + + /* Add a suffix to the program name if this is a process with a + * none default configuration file name. */ + if (strcmp( CONFIGFILE, get_dyn_CONFIGFILE()) == 0) { + name = SMB_STRDUP(program_name); + } else { + short_configfile = strrchr( get_dyn_CONFIGFILE(), '/'); + if (short_configfile == NULL) { + /* conf file in current directory */ + short_configfile = get_dyn_CONFIGFILE(); + } else { + /* full/relative path provided */ + short_configfile++; + } + if (asprintf(&name, "%s-%s", program_name, + short_configfile) == -1) { + smb_panic("asprintf failed"); + } + } + + if (asprintf(&pidFile, "%s/%s.pid", lp_piddir(), name) == -1) { + smb_panic("asprintf failed"); + } + + pid = pidfile_pid(name); + if (pid != 0) { + DEBUG(0,("ERROR: %s is already running. File %s exists and process id %d is running.\n", + name, pidFile, (int)pid)); + exit(1); + } + + fd = sys_open(pidFile, O_NONBLOCK | O_CREAT | O_WRONLY | O_EXCL, 0644); + if (fd == -1) { + DEBUG(0,("ERROR: can't open %s: Error was %s\n", pidFile, + strerror(errno))); + exit(1); + } + + if (fcntl_lock(fd,SMB_F_SETLK,0,1,F_WRLCK)==False) { + DEBUG(0,("ERROR: %s : fcntl lock of file %s failed. Error was %s\n", + name, pidFile, strerror(errno))); + exit(1); + } + + memset(buf, 0, sizeof(buf)); + slprintf(buf, sizeof(buf) - 1, "%u\n", (unsigned int) sys_getpid()); + if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) { + DEBUG(0,("ERROR: can't write to file %s: %s\n", + pidFile, strerror(errno))); + exit(1); + } + /* Leave pid file open & locked for the duration... */ + SAFE_FREE(name); + SAFE_FREE(pidFile); +} |