+/******************************************************************************/
+/* pfixtools: a collection of postfix related tools */
+/* ~~~~~~~~~ */
+/* ________________________________________________________________________ */
+/* */
+/* Redistribution and use in source and binary forms, with or without */
+/* modification, are permitted provided that the following conditions */
+/* are met: */
+/* */
+/* 1. Redistributions of source code must retain the above copyright */
+/* notice, this list of conditions and the following disclaimer. */
+/* 2. Redistributions in binary form must reproduce the above copyright */
+/* notice, this list of conditions and the following disclaimer in the */
+/* documentation and/or other materials provided with the distribution. */
+/* 3. The names of its contributors may not be used to endorse or promote */
+/* products derived from this software without specific prior written */
+/* permission. */
+/* */
+/* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND */
+/* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE */
+/* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
+/* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS */
+/* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR */
+/* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF */
+/* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS */
+/* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */
+/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) */
+/* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF */
+/* THE POSSIBILITY OF SUCH DAMAGE. */
+/******************************************************************************/
+
+/*
+ * Copyright © 2007 Pierre Habouzit
+ * Copyright © 2008 Florent Bruneau
+ */
+
+#include <fcntl.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sys/un.h>
+
+#include "common.h"
+
+sig_atomic_t sigint = false;
+sig_atomic_t sighup = false;
+
+static FILE *pidfile = NULL;
+
+void common_sighandler(int sig)
+{
+ switch (sig) {
+ case SIGINT:
+ sigint = true;
+ return;
+
+ case SIGHUP:
+ sighup = true;
+ return;
+
+ default:
+ syslog(LOG_ERR, "Killed (got signal %d)...", sig);
+ exit(-1);
+ }
+}
+
+static int setnonblock(int sock)
+{
+ int res = fcntl(sock, F_GETFL);
+
+ if (res < 0) {
+ UNIXERR("fcntl");
+ return -1;
+ }
+
+ if (fcntl(sock, F_SETFL, res | O_NONBLOCK) < 0) {
+ UNIXERR("fcntl");
+ return -1;
+ }
+
+ return 0;
+}
+
+int tcp_bind(const struct sockaddr *addr, socklen_t len)
+{
+ int sock;
+
+ switch (addr->sa_family) {
+ case AF_UNIX:
+ unlink(((struct sockaddr_un *)addr)->sun_path);
+ sock = socket(PF_UNIX, SOCK_STREAM, 0);
+ break;
+ case AF_INET:
+ sock = socket(PF_INET, SOCK_STREAM, 0);
+ break;
+ case AF_INET6:
+ sock = socket(PF_INET6, SOCK_STREAM, 0);
+ break;
+ default:
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (sock < 0) {
+ UNIXERR("socket");
+ return -1;
+ }
+
+ if (addr->sa_family != AF_UNIX) {
+ int v = 1;
+ if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) < 0) {
+ UNIXERR("setsockopt(SO_REUSEADDR)");
+ close(sock);
+ return -1;
+ }
+ }
+
+ if (bind(sock, addr, len) < 0) {
+ UNIXERR("bind");
+ close(sock);
+ return -1;
+ }
+
+ return sock;
+}
+
+int tcp_listen(const struct sockaddr *addr, socklen_t len)
+{
+ int sock = tcp_bind(addr, len);
+ if (listen(sock, 0) < 0) {
+ UNIXERR("bind");
+ close(sock);
+ return -1;
+ }
+ return sock;
+}
+
+int tcp_listen_nonblock(const struct sockaddr *addr, socklen_t len)
+{
+ int sock = tcp_bind(addr, len);
+ if (setnonblock(sock)) {
+ close(sock);
+ return -1;
+ }
+ if (listen(sock, 0) < 0) {
+ UNIXERR("bind");
+ close(sock);
+ return -1;
+ }
+ return sock;
+}
+
+int accept_nonblock(int fd)
+{
+ int sock = accept(fd, NULL, 0);
+
+ if (sock < 0) {
+ UNIXERR("accept");
+ return -1;
+ }
+
+ if (setnonblock(sock)) {
+ close(sock);
+ return -1;
+ }
+
+ return sock;
+}
+
+int xwrite(int fd, const char *s, size_t l)
+{
+ while (l > 0) {
+ int nb = write(fd, s, l);
+ if (nb < 0) {
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ return -1;
+ }
+ l -= nb;
+ }
+ return 0;
+}
+
+int daemon_detach(void)
+{
+ pid_t pid;
+
+ close(STDIN_FILENO);
+ close(STDOUT_FILENO);
+ close(STDERR_FILENO);
+
+ open("/dev/null", O_RDWR);
+ open("/dev/null", O_RDWR);
+ open("/dev/null", O_RDWR);
+
+ pid = fork();
+ if (pid < 0)
+ return -1;
+ if (pid)
+ exit(0);
+
+ setsid();
+ return 0;
+}
+
+int drop_privileges(const char *user, const char *group)
+{
+ if (!geteuid()) {
+ struct passwd *pw;
+ struct group *gr;
+
+ if (group) {
+ gr = getgrnam(group);
+ if (!gr)
+ return -1;
+ setgid(gr->gr_gid);
+ }
+
+ pw = getpwnam(user);
+ if (!pw)
+ return -1;
+ if (!group) {
+ setgid(pw->pw_gid);
+ }
+ setuid(pw->pw_uid);
+ }
+
+ return 0;
+}
+
+int pidfile_open(const char *name)
+{
+ if (name) {
+ pidfile = fopen(name, "w");
+ if (!pidfile)
+ return -1;
+ fprintf(pidfile, "%d\n", getpid());
+ return fflush(pidfile);
+ }
+ return 0;
+}
+
+int pidfile_refresh(void)
+{
+ if (pidfile) {
+ rewind(pidfile);
+ ftruncate(fileno(pidfile), 0);
+ fprintf(pidfile, "%d\n", getpid());
+ return fflush(pidfile);
+ }
+ return 0;
+}
+
+static void pidfile_close(void)
+{
+ if (pidfile) {
+ rewind(pidfile);
+ ftruncate(fileno(pidfile), 0);
+ fclose(pidfile);
+ pidfile = NULL;
+ }
+}
+
+int common_setup(const char* pidfilename, bool unsafe, const char* runas_user,
+ const char* runas_group, bool daemonize)
+{
+ if (pidfile_open(pidfilename) < 0) {
+ syslog(LOG_CRIT, "unable to write pidfile %s", pidfilename);
+ return EXIT_FAILURE;
+ }
+
+ if (!unsafe && drop_privileges(runas_user, runas_group) < 0) {
+ syslog(LOG_CRIT, "unable to drop privileges");
+ return EXIT_FAILURE;
+ }
+
+ if (daemonize && daemon_detach() < 0) {
+ syslog(LOG_CRIT, "unable to fork");
+ return EXIT_FAILURE;
+ }
+
+ pidfile_refresh();
+ return EXIT_SUCCESS;
+}
+
+extern initcall_t __madinit[];
+extern exitcall_t __madexit[];
+
+static void common_shutdown(void)
+{
+ syslog(LOG_INFO, "Stopping...");
+ pidfile_close();
+
+ for (int i = -1; __madexit[i]; i--) {
+ (*__madexit[i])();
+ }
+}
+
+static void __attribute__((__constructor__,__used__))
+common_initialize(void)
+{
+ if (atexit(common_shutdown)) {
+ fputs("Cannot hook my atexit function, quitting !\n", stderr);
+ abort();
+ }
+
+ for (int i = 0; __madinit[i]; i++) {
+ if ((*__madinit[i])()) {
+ exit(EXIT_FAILURE);
+ }
+ }
+}
+