Merge remote-tracking branch 'origin/master'

[libucw.git] / ucw / daemon.c

diff --git a/ucw/daemon.c b/ucw/daemon.c
index 0c83bdeb5aba8f89106a89a027a121f2a8d2a39c..9b136d8ac2c171434d6d2d893dc4d824b73068f7 100644 (file)
--- a/ucw/daemon.c
+++ b/ucw/daemon.c
@@ -1,7 +1,7 @@
 /*
  *     UCW Library -- Daemonization
  *
 /*
  *     UCW Library -- Daemonization
  *

- *     (c) 2012 Martin Mares <mj@ucw.cz>
+ *     (c) 2012--2014 Martin Mares <mj@ucw.cz>

  *
  *     This software may be freely distributed and used according to the terms
  *     of the GNU Lesser General Public License.
  *
  *     This software may be freely distributed and used according to the terms
  *     of the GNU Lesser General Public License.


@@ -18,8 +18,12 @@
 #include <pwd.h>
 #include <grp.h>
 #include <errno.h>
 #include <pwd.h>
 #include <grp.h>
 #include <errno.h>

+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>

 
 

-static void daemon_resolve_ugid(struct daemon_params *dp)
+void
+daemon_resolve_ugid(struct daemon_params *dp)

 {
   // Resolve user name
   const char *u = dp->run_as_user;
 {
   // Resolve user name
   const char *u = dp->run_as_user;


@@ -28,8 +32,8 @@ static void daemon_resolve_ugid(struct daemon_params *dp)
     {
       if (u[0] == '#')
        {
     {
       if (u[0] == '#')
        {

-         uns id;
-         const char *err = str_to_uns(&id, u, NULL, 10 | STN_WHOLE);
+         uint id;
+         const char *err = str_to_uint(&id, u, NULL, 10 | STN_WHOLE);

          if (err)
            die("Cannot parse user `%s': %s", u, err);
          dp->run_as_uid = id;
          if (err)
            die("Cannot parse user `%s': %s", u, err);
          dp->run_as_uid = id;


@@ -52,8 +56,8 @@ static void daemon_resolve_ugid(struct daemon_params *dp)
     {
       if (g[0] == '#')
        {
     {
       if (g[0] == '#')
        {

-         uns id;
-         const char *err = str_to_uns(&id, g, NULL, 10 | STN_WHOLE);
+         uint id;
+         const char *err = str_to_uint(&id, g, NULL, 10 | STN_WHOLE);

          if (err)
            die("Cannot parse group `%s': %s", g, err);
          dp->run_as_gid = id;
          if (err)
            die("Cannot parse group `%s': %s", g, err);
          dp->run_as_gid = id;


@@ -75,10 +79,24 @@ static void daemon_resolve_ugid(struct daemon_params *dp)
     }
 }
 
     }
 }
 

-void daemon_init(struct daemon_params *dp)
+void daemon_switch_ugid(struct daemon_params *dp)
+{
+  if (dp->want_setgid && setresgid(dp->run_as_gid, dp->run_as_gid, dp->run_as_gid) < 0)
+    die("Cannot set GID to %d: %m", (int) dp->run_as_gid);
+  if (dp->want_setgid > 1 && initgroups(dp->run_as_user, dp->run_as_gid) < 0)
+    die("Cannot initialize groups: %m");
+  if (dp->want_setuid && setresuid(dp->run_as_uid, dp->run_as_uid, dp->run_as_uid) < 0)
+    die("Cannot set UID to %d: %m", (int) dp->run_as_uid);
+}
+
+void
+daemon_init(struct daemon_params *dp)

 {
   daemon_resolve_ugid(dp);
 
 {
   daemon_resolve_ugid(dp);
 

+  if (dp->flags & DAEMON_FLAG_SIMULATE)
+    return;
+

   if (dp->pid_file)
     {
       // Check that PID file path is absolute
   if (dp->pid_file)
     {
       // Check that PID file path is absolute


@@ -89,12 +107,14 @@ void daemon_init(struct daemon_params *dp)
       dp->pid_fd = open(dp->pid_file, O_RDWR | O_CREAT, 0666);
       if (dp->pid_fd < 0)
        die("Cannot open `%s': %m", dp->pid_file);
       dp->pid_fd = open(dp->pid_file, O_RDWR | O_CREAT, 0666);
       if (dp->pid_fd < 0)
        die("Cannot open `%s': %m", dp->pid_file);

+      int fl = fcntl(dp->pid_fd, F_GETFD);
+      if (fl < 0 || fcntl(dp->pid_fd, F_SETFD, fl | FD_CLOEXEC))
+       die("Cannot set FD_CLOEXEC: %m");

 
       // Try to lock it with an exclusive lock
 
       // Try to lock it with an exclusive lock

-      struct flock fl = { .l_type = F_WRLCK, .l_whence = SEEK_SET };
-      if (fcntl(dp->pid_fd, F_SETLK, &fl) < 0)
+      if (flock(dp->pid_fd, LOCK_EX | LOCK_NB) < 0)

        {
        {

-         if (errno == EAGAIN || errno == EACCES)
+         if (errno == EINTR || errno == EWOULDBLOCK)

            die("Daemon is already running (`%s' locked)", dp->pid_file);
          else
            die("Cannot lock `%s': %m", dp->pid_file);
            die("Daemon is already running (`%s' locked)", dp->pid_file);
          else
            die("Cannot lock `%s': %m", dp->pid_file);


@@ -107,15 +127,17 @@ void daemon_init(struct daemon_params *dp)
     }
 }
 
     }
 }
 

-void daemon_run(struct daemon_params *dp, void (*body)(struct daemon_params *dp))
+void
+daemon_run(struct daemon_params *dp, void (*body)(struct daemon_params *dp))

 {
 {

+  if (dp->flags & DAEMON_FLAG_SIMULATE)
+    {
+      body(dp);
+      return;
+    }
+

   // Switch GID and UID
   // Switch GID and UID

-  if (dp->want_setgid && setresgid(dp->run_as_gid, dp->run_as_gid, dp->run_as_gid) < 0)
-    die("Cannot set GID to %d: %m", (int) dp->run_as_gid);
-  if (dp->want_setgid > 1 && initgroups(dp->run_as_user, dp->run_as_gid) < 0)
-    die("Cannot initialize groups: %m");
-  if (dp->want_setuid && setresuid(dp->run_as_uid, dp->run_as_uid, dp->run_as_uid) < 0)
-    die("Cannot set UID to %d: %m", (int) dp->run_as_uid);
+  daemon_switch_ugid(dp);

 
   // Create a new session and close stdio
   setsid();
 
   // Create a new session and close stdio
   setsid();


@@ -140,13 +162,12 @@ void daemon_run(struct daemon_params *dp, void (*body)(struct daemon_params *dp)
     die("Cannot fork: %m");
   if (!pid)
     {
     die("Cannot fork: %m");
   if (!pid)
     {

-      // The PID file is left open, so that it is kept locked
-      // FIXME: Downgrade the lock to shared
+      // We still keep the PID file open and thus locked

       body(dp);
       exit(0);
     }
       body(dp);
       exit(0);
     }

-  
-  // Write PID and release the PID file
+
+  // Write PID

   if (dp->pid_file)
     {
       char buf[32];
   if (dp->pid_file)
     {
       char buf[32];


@@ -154,14 +175,18 @@ void daemon_run(struct daemon_params *dp, void (*body)(struct daemon_params *dp)
       ASSERT(c <= (int) sizeof(buf));
       if (lseek(dp->pid_fd, 0, SEEK_SET) < 0 ||
          write(dp->pid_fd, buf, c) != c ||
       ASSERT(c <= (int) sizeof(buf));
       if (lseek(dp->pid_fd, 0, SEEK_SET) < 0 ||
          write(dp->pid_fd, buf, c) != c ||

-         ftruncate(dp->pid_fd, c) < 0 ||
+         ftruncate(dp->pid_fd, c) ||

          close(dp->pid_fd) < 0)
        die("Cannot write PID to `%s': %m", dp->pid_file);
     }
 }
 
          close(dp->pid_fd) < 0)
        die("Cannot write PID to `%s': %m", dp->pid_file);
     }
 }
 

-void daemon_exit(struct daemon_params *dp)
+void
+daemon_exit(struct daemon_params *dp)

 {
 {

+  if (dp->flags & DAEMON_FLAG_SIMULATE)
+    return;
+

   if (dp->pid_file)
     {
       if (unlink(dp->pid_file) < 0)
   if (dp->pid_file)
     {
       if (unlink(dp->pid_file) < 0)


@@ -172,21 +197,70 @@ void daemon_exit(struct daemon_params *dp)
 
 #ifdef TEST
 
 
 #ifdef TEST
 

+#include <signal.h>
+
+static volatile sig_atomic_t terminate;
+
+static void term_handler(int sig UNUSED)
+{
+  msg(L_INFO | L_SIGHANDLER, "SIGTERM received, terminating in a while");
+  terminate = 1;
+}
+
+static void hup_handler(int sig UNUSED)
+{
+  msg(L_INFO | L_SIGHANDLER, "SIGHUP received");
+}
+

 static void body(struct daemon_params *dp)
 {
   log_fork();
   msg(L_INFO, "Daemon is running");
 static void body(struct daemon_params *dp)
 {
   log_fork();
   msg(L_INFO, "Daemon is running");

-  sleep(60);
+  msg(L_INFO, "uid=%d/%d gid=%d/%d", (int) getuid(), (int) geteuid(), (int) getgid(), (int) getegid());
+
+  struct sigaction sa_term = { .sa_handler = term_handler };
+  struct sigaction sa_hup = { .sa_handler = hup_handler };
+  if (sigaction(SIGTERM, &sa_term, NULL) < 0 ||
+      sigaction(SIGHUP, &sa_hup, NULL) < 0)
+    ASSERT(0);
+
+  while (!terminate)
+    {
+      if (!sleep(60))
+       {
+         msg(L_INFO, "Timeout elapsed, terminating in a while");
+         break;
+       }
+    }
+
+  sleep(2);

   msg(L_INFO, "Daemon is shutting down");
   daemon_exit(dp);
 }
 
   msg(L_INFO, "Daemon is shutting down");
   daemon_exit(dp);
 }
 

-int main(void)
+int main(int argc, char **argv)

 {
   struct daemon_params dp = {
     .pid_file = "/tmp/123",
   };
 
 {
   struct daemon_params dp = {
     .pid_file = "/tmp/123",
   };
 

+  int opt;
+  while ((opt = getopt(argc, argv, "p:u:g:")) >= 0)
+    switch (opt)
+      {
+      case 'p':
+       dp.pid_file = optarg;
+       break;
+      case 'u':
+       dp.run_as_user = optarg;
+       break;
+      case 'g':
+       dp.run_as_group = optarg;
+       break;
+      default:
+       die("Invalid arguments");
+      }
+

   daemon_init(&dp);
   daemon_run(&dp, body);
   msg(L_INFO, "Main program has ended");
   daemon_init(&dp);
   daemon_run(&dp, body);
   msg(L_INFO, "Main program has ended");