From 569e7078244470ac0fcc2af3947c2735338555ec Mon Sep 17 00:00:00 2001
From: Martin Sehnoutka <msehnout@redhat.com>
Date: Wed, 7 Sep 2016 11:29:29 +0200
Subject: [PATCH 10/33] Improve daemonizing

Init script gets correct return code if binding fails.
---
 standalone.c | 38 +++++++++++++++++++++++++++++++++++++-
 sysutil.c    | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 sysutil.h    |  7 ++++++-
 3 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/standalone.c b/standalone.c
index e0f2d5b..3b65ea2 100644
--- a/standalone.c
+++ b/standalone.c
@@ -26,6 +26,8 @@ static unsigned int s_ipaddr_size;
 
 static void handle_sigchld(void*  duff);
 static void handle_sighup(void*  duff);
+static void handle_sigusr1(int sig);
+static void handle_sigalrm(int sig);
 static void prepare_child(int sockfd);
 static unsigned int handle_ip_count(void* p_raw_addr);
 static void drop_ip_count(void* p_raw_addr);
@@ -46,11 +48,23 @@ vsf_standalone_main(void)
   }
   if (tunable_background)
   {
+    vsf_sysutil_sigaction(kVSFSysUtilSigALRM, handle_sigalrm);
+    vsf_sysutil_sigaction(kVSFSysUtilSigUSR1, handle_sigusr1);
+
     int forkret = vsf_sysutil_fork();
     if (forkret > 0)
     {
       /* Parent, just exit */
-      vsf_sysutil_exit(0);
+      vsf_sysutil_set_alarm(3);
+      vsf_sysutil_pause();
+
+      vsf_sysutil_exit(1);
+    }
+    else if (forkret == 0)
+    {
+      // Son, restore original signal handler
+      vsf_sysutil_sigaction(kVSFSysUtilSigALRM, 0L);
+      vsf_sysutil_sigaction(kVSFSysUtilSigUSR1, 0L);
     }
     /* Son, close standard FDs to avoid SSH hang-on-exit */
     vsf_sysutil_reopen_standard_fds();
@@ -99,6 +113,10 @@ vsf_standalone_main(void)
     {
       die("could not bind listening IPv4 socket");
     }
+    if (tunable_background)
+    {
+      vsf_sysutil_kill(vsf_sysutil_getppid(), kVSFSysUtilSigUSR1);
+    }
   }
   else
   {
@@ -129,6 +147,10 @@ vsf_standalone_main(void)
     {
       die("could not bind listening IPv6 socket");
     }
+    if (tunable_background)
+    {
+      vsf_sysutil_kill(vsf_sysutil_getppid(), kVSFSysUtilSigUSR1);
+    }
   }
   vsf_sysutil_close(0);
   vsf_sysutil_close(1);
@@ -268,6 +290,20 @@ handle_sighup(void* duff)
   vsf_parseconf_load_file(0, 0);
 }
 
+static void
+handle_sigalrm(int sig)
+{
+  (void)sig; // avoid unused parameter error
+  vsf_sysutil_exit(1);
+}
+
+static void
+handle_sigusr1(int sig)
+{
+  (void)sig; // avoid unused parameter error
+  vsf_sysutil_exit(0);
+}
+
 static unsigned int
 hash_ip(unsigned int buckets, void* p_key)
 {
diff --git a/sysutil.c b/sysutil.c
index 428a34a..c848356 100644
--- a/sysutil.c
+++ b/sysutil.c
@@ -201,6 +201,9 @@ vsf_sysutil_translate_sig(const enum EVSFSysUtilSignal sig)
     case kVSFSysUtilSigHUP:
       realsig = SIGHUP;
       break;
+    case kVSFSysUtilSigUSR1:
+      realsig = SIGUSR1;
+      break;
     default:
       bug("unknown signal in vsf_sysutil_translate_sig");
       break;
@@ -549,6 +552,12 @@ vsf_sysutil_getpid(void)
   return (unsigned int) s_current_pid;
 }
 
+unsigned int
+vsf_sysutil_getppid(void)
+{
+  return (unsigned int)getppid();
+}
+
 int
 vsf_sysutil_fork(void)
 {
@@ -2871,3 +2880,53 @@ vsf_sysutil_post_fork()
     s_sig_details[i].pending = 0;
   }
 }
+
+static struct sigaction sigalr, sigusr1;
+
+void
+vsf_sysutil_sigaction(const enum EVSFSysUtilSignal sig, void (*p_handlefunc)(int))
+{
+  int realsig = vsf_sysutil_translate_sig(sig);
+  int retval;
+  struct sigaction sigact, *origsigact=NULL;
+  if (realsig==SIGALRM)
+  {
+    origsigact = &sigalr;
+  }
+  else if (realsig==SIGUSR1)
+  {
+    origsigact = &sigusr1;
+  }
+  vsf_sysutil_memclr(&sigact, sizeof(sigact));
+  if (p_handlefunc != NULL)
+  {
+    sigact.sa_handler = p_handlefunc;
+    retval = sigfillset(&sigact.sa_mask);
+    if (retval != 0)
+    {
+      die("sigfillset");
+    }
+    retval = sigaction(realsig, &sigact, origsigact);
+  }
+  else
+  {
+    retval = sigaction(realsig, origsigact, NULL);
+  }
+  if (retval != 0)
+  {
+    die("sigaction");
+  }
+}
+
+int
+vsf_sysutil_kill(int pid, int sig)
+{
+  int realsig = vsf_sysutil_translate_sig(sig);
+  return kill(pid, realsig);
+}
+
+int
+vsf_sysutil_pause()
+{
+  return pause();
+}
diff --git a/sysutil.h b/sysutil.h
index c2ddd15..bfc92cb 100644
--- a/sysutil.h
+++ b/sysutil.h
@@ -30,7 +30,8 @@ enum EVSFSysUtilSignal
   kVSFSysUtilSigCHLD,
   kVSFSysUtilSigPIPE,
   kVSFSysUtilSigURG,
-  kVSFSysUtilSigHUP
+  kVSFSysUtilSigHUP,
+  kVSFSysUtilSigUSR1
 };
 enum EVSFSysUtilInterruptContext
 {
@@ -165,6 +166,7 @@ void vsf_sysutil_free(void* p_ptr);
 
 /* Process creation/exit/process handling */
 unsigned int vsf_sysutil_getpid(void);
+unsigned int vsf_sysutil_getppid(void);
 void vsf_sysutil_post_fork(void);
 int vsf_sysutil_fork(void);
 int vsf_sysutil_fork_failok(void);
@@ -182,6 +184,9 @@ int vsf_sysutil_wait_exited_normally(
   const struct vsf_sysutil_wait_retval* p_waitret);
 int vsf_sysutil_wait_get_exitcode(
   const struct vsf_sysutil_wait_retval* p_waitret);
+void vsf_sysutil_sigaction(const enum EVSFSysUtilSignal sig, void (*p_handlefunc)(int));
+int vsf_sysutil_kill(int pid, int sig);
+int vsf_sysutil_pause();
 
 /* Various string functions */
 unsigned int vsf_sysutil_strlen(const char* p_text);
-- 
2.7.4