diff options
Diffstat (limited to 'nslcd/daemonize.c')
| -rw-r--r-- | nslcd/daemonize.c | 221 |
1 files changed, 0 insertions, 221 deletions
diff --git a/nslcd/daemonize.c b/nslcd/daemonize.c deleted file mode 100644 index 0d96f73..0000000 --- a/nslcd/daemonize.c +++ /dev/null @@ -1,221 +0,0 @@ -/* - daemoninze.c - functions for properly daemonising an application - - Copyright (C) 2014 Arthur de Jong - - This library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - This library 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with this library; if not, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - 02110-1301 USA -*/ - -#include "config.h" - -#include <unistd.h> -#include <sys/types.h> -#include <sys/stat.h> -#include <fcntl.h> -#include <string.h> -#include <errno.h> -#include <stdio.h> -#include <stdlib.h> -#ifdef HAVE_PTHREAD_H -#include <pthread.h> -#endif /* HAVE_PTHREAD_H */ - -#include "daemonize.h" -#include "log.h" - -/* the write end of a pipe that is used to signal the fact that the child - process has finished initialising (see daemonize_daemon() and - daemonize_ready() for details) */ -static int daemonizefd = -1; - -void daemonize_closefds(void) -{ - int i; - /* close all file descriptors (except stdin/out/err) */ - i = sysconf(_SC_OPEN_MAX) - 1; - /* if the system does not have OPEN_MAX just close the first 32 and - hope we closed enough */ - if (i < 0) - i = 32; - for (; i > 3; i--) - close(i); -} - -void daemonize_redirect_stdio(void) -{ - /* close stdin, stdout and stderr */ - close(0); /* stdin */ - close(1); /* stdout */ - close(2); /* stderr */ - /* reconnect to /dev/null */ - open("/dev/null", O_RDWR); /* stdin, fd=0 */ - dup(0); /* stdout, fd=1 */ - dup(0); /* stderr, fd=2 */ -} - -/* try to fill the buffer until EOF or error */ -static int read_response(int fd, char *buffer, size_t bufsz) -{ - int rc; - size_t r = 0; - while (r < bufsz) - { - rc = read(fd, buffer + r, bufsz - r); - if (rc == 0) - break; - else if (rc > 0) - r += rc; - else if ((errno == EINTR) || (errno == EAGAIN)) - continue; /* ignore these errors and try again */ - else - { - log_log(LOG_ERR, "read_response(): read() failed: %s", strerror(errno)); - return -1; - } - } - return r; -} - -/* ihe process calling daemonize_daemon() will end up here on success */ -static int wait_for_response(int fd) -{ - int i, l, rc; - char buffer[1024]; - /* read return code */ - i = read_response(fd, (void *)&rc, sizeof(int)); - if (i != sizeof(int)) - return -1; - /* read string length */ - i = read_response(fd, (void *)&l, sizeof(int)); - if ((i != sizeof(int)) || (l <= 0)) - _exit(rc); - /* read string */ - if ((size_t)l > (sizeof(buffer) - 1)) - l = sizeof(buffer) - 1; - i = read_response(fd, buffer, l); - buffer[sizeof(buffer) - 1] = '\0'; - if (i == l) - fprintf(stderr, "%s", buffer); - _exit(rc); -} - -static void closefd(void) -{ - if (daemonizefd >= 0) - { - close(daemonizefd); - daemonizefd = -1; - } -} - -int daemonize_daemon(void) -{ - int pipefds[2]; - int i; - /* set up a pipe for communication */ - if (pipe(pipefds) < 0) - { - log_log(LOG_ERR, "pipe() failed: %s", strerror(errno)); - return -1; - } - /* set O_NONBLOCK on the write end to ensure that a call to - daemonize_ready() will not lock the application */ - if ((i = fcntl(pipefds[1], F_GETFL, 0)) < 0) - { - log_log(LOG_ERR, "fcntl() failed: %s", strerror(errno)); - close(pipefds[0]); - close(pipefds[1]); - return -1; - } - if (fcntl(pipefds[1], F_SETFL, i | O_NONBLOCK) < 0) - { - log_log(LOG_ERR, "fcntl() failed: %s", strerror(errno)); - close(pipefds[0]); - close(pipefds[1]); - return -1; - } - /* fork() and exit() to detach from the parent process */ - switch (fork()) - { - case 0: - /* we are the child, close read end of pipe */ - close(pipefds[0]); - break; - case -1: - /* we are the parent, but have an error */ - log_log(LOG_ERR, "fork() failed: %s", strerror(errno)); - close(pipefds[0]); - close(pipefds[1]); - return -1; - default: - /* we are the parent, close write end and wait for information */ - close(pipefds[1]); - return wait_for_response(pipefds[0]); - } - /* become process leader */ - if (setsid() < 0) - { - log_log(LOG_ERR, "setsid() failed: %s", strerror(errno)); - close(pipefds[1]); - _exit(EXIT_FAILURE); - } - /* fork again so we cannot allocate a pty */ - switch (fork()) - { - case 0: - /* we are the child */ - break; - case -1: - /* we are the parent, but have an error */ - log_log(LOG_ERR, "fork() failed: %s", strerror(errno)); - close(pipefds[1]); - _exit(EXIT_FAILURE); - default: - /* we are the parent and we're done */ - close(pipefds[1]); - _exit(EXIT_SUCCESS); - } - daemonizefd = pipefds[1]; - /* close the file descriptor on exec (ignore errors) */ - fcntl(daemonizefd, F_SETFD, FD_CLOEXEC); -#ifdef HAVE_PTHREAD_ATFORK - /* handle any other forks by closing daemonizefd first */ - (void)pthread_atfork(NULL, NULL, closefd); -#endif /* HAVE_PTHREAD_ATFORK */ - return 0; -} - -void daemonize_ready(int status, const char *message) -{ - if (daemonizefd >= 0) - { - /* we ignore any errors writing */ - write(daemonizefd, &status, sizeof(int)); - if ((message == NULL) || (message[0] == '\0')) - { - status = 0; - write(daemonizefd, &status, sizeof(int)); - } - else - { - status = strlen(message); - write(daemonizefd, &status, sizeof(int)); - write(daemonizefd, message, status); - } - close(daemonizefd); - daemonizefd = -1; - } -} |