From 72a240776fcd8f299dc55809a1ec183749e57e61 Mon Sep 17 00:00:00 2001
From: Alaa Eddine Elamri <alaeddine.elamri@bareos.com>
Date: Mon, 25 Oct 2021 12:57:50 +0200
Subject: [PATCH] daemons: lib: locking and unlocking pidfile in main program
 before fork

s
---
 core/src/dird/dird.cc     |  2 +-
 core/src/filed/filed.cc   |  4 ++--
 core/src/lib/bsys.cc      | 24 ++++++++++++++++++++++--
 core/src/lib/bsys.h       |  3 ++-
 core/src/lib/daemon.cc    |  2 ++
 core/src/stored/stored.cc |  4 ++--
 6 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/core/src/dird/dird.cc b/core/src/dird/dird.cc
index 9e4ba77e7d4..74ea20aa8cb 100644
--- a/core/src/dird/dird.cc
+++ b/core/src/dird/dird.cc
@@ -339,7 +339,7 @@ int main(int argc, char* argv[])
 
   int pidfile_fd = -1;
   if (!test_config && background && pidfile_path) {
-    pidfile_fd = CreatePidFile(pidfile_path);
+    pidfile_fd = CreatePidFile("bareos-dir", pidfile_path);
   }
 
   // See if we want to drop privs.
diff --git a/core/src/filed/filed.cc b/core/src/filed/filed.cc
index 033a66964f2..b5fbb3cf8cc 100644
--- a/core/src/filed/filed.cc
+++ b/core/src/filed/filed.cc
@@ -221,9 +221,9 @@ int main(int argc, char* argv[])
     Emsg0(M_ERROR_TERM, 0, _("-k option has no meaning without -u option.\n"));
   }
 
-  int pidfile_fd = 0;
+  int pidfile_fd = -1;
   if (!foreground && !test_config && pidfile_path) {
-    pidfile_fd = CreatePidFile(pidfile_path);
+    pidfile_fd = CreatePidFile("bareos-fd", pidfile_path);
   }
 
   // See if we want to drop privs.
diff --git a/core/src/lib/bsys.cc b/core/src/lib/bsys.cc
index 90bb2aaa770..1e385b315d8 100644
--- a/core/src/lib/bsys.cc
+++ b/core/src/lib/bsys.cc
@@ -417,7 +417,6 @@ int b_strerror(int errnum, char* buf, size_t bufsiz)
   return status;
 }
 
-
 static void LockPidFile(const char* progname,
                         int pidfile_fd,
                         const char* pidfile_path)
@@ -446,6 +445,24 @@ static void LockPidFile(const char* progname,
   }
 #endif
 }
+
+void UnlockPidFile(int pidfile_fd, const char* pidfile_path)
+{
+#if !defined(HAVE_WIN32)
+  struct flock fl;
+
+  fl.l_type = F_UNLCK;
+  fl.l_whence = SEEK_SET;
+  fl.l_start = 0;
+  fl.l_len = 0;
+
+  if (fcntl(pidfile_fd, F_SETLK, &fl)) {
+    BErrNo be;
+    Emsg2(M_ERROR_TERM, 0, _("Unable to unlock PID file '%s'. ERR=%s\n"),
+          pidfile_path, be.bstrerror());
+  }
+#endif
+}
 /*
    The content of this function (CreatePidFile) was inspired and modified to fit
    current needs from filelock/create_pid_file.c (Listing 55-4, page 1143), an
@@ -458,7 +475,7 @@ static void LockPidFile(const char* progname,
 
 #define CPF_CLOEXEC 1
 
-int CreatePidFile(const char* pidfile_path)
+int CreatePidFile(const char* progname, const char* pidfile_path)
 {
 #if !defined(HAVE_WIN32)
   int pidfd;
@@ -494,6 +511,9 @@ int CreatePidFile(const char* pidfile_path)
             pidfile_path, be.bstrerror());
     }
   }
+
+  LockPidFile(progname, pidfd, pidfile_path);
+
   return pidfd;
 #endif
 }
diff --git a/core/src/lib/bsys.h b/core/src/lib/bsys.h
index 21a23432fab..bbf4ddac9d0 100644
--- a/core/src/lib/bsys.h
+++ b/core/src/lib/bsys.h
@@ -36,11 +36,12 @@ int cstrlen(const char* str);
 int Bsnprintf(char* str, int32_t size, const char* format, ...);
 int Bvsnprintf(char* str, int32_t size, const char* format, va_list ap);
 int PoolSprintf(char* pool_buf, const char* fmt, ...);
-int CreatePidFile(const char* pidfile_path);
+int CreatePidFile(const char* progname, const char* pidfile_path);
 void WritePidFile(const int& pidfile_fd,
                   const char* pidfile_path,
                   const pid_t& forkpid,
                   const char* progname);
+void UnlockPidFile(int pidfile_fd, const char* pidfile_path);
 int DeletePidFile(const char* pidfile_path);
 void drop(char* uid, char* gid, bool keep_readall_caps);
 int Bmicrosleep(int32_t sec, int32_t usec);
diff --git a/core/src/lib/daemon.cc b/core/src/lib/daemon.cc
index b2d593d423b..2369e4c30d3 100644
--- a/core/src/lib/daemon.cc
+++ b/core/src/lib/daemon.cc
@@ -68,6 +68,8 @@ void daemon_start(const char* progname, int pidfile_fd, char* pidfile_path)
 {
   Dmsg0(900, "Enter daemon_start\n");
 
+  if (pidfile_path) { UnlockPidFile(pidfile_fd, pidfile_path); }
+
   pid_t forkpid = fork();
 
   switch (forkpid) {
diff --git a/core/src/stored/stored.cc b/core/src/stored/stored.cc
index f9b250f6ceb..ca136e6ec1c 100644
--- a/core/src/stored/stored.cc
+++ b/core/src/stored/stored.cc
@@ -252,9 +252,9 @@ int main(int argc, char* argv[])
   }
   if (argc) { usage(); }
 
-  int pidfile_fd = 0;
+  int pidfile_fd = -1;
   if (!foreground && !test_config && pidfile_path) {
-    pidfile_fd = CreatePidFile(pidfile_path);
+    pidfile_fd = CreatePidFile("bareos-sd", pidfile_path);
   }
 
   // See if we want to drop privs.