From 958f694b6f4527ac8220a3a2b46f9ec383c708d2 Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Tue, 14 Jun 2016 21:36:08 -0700
Subject: [PATCH] dll: fuse: Cygwin signal handling support

---
 inc/fuse/fuse_common.h   |  3 ++-
 inc/fuse/winfsp_fuse.h   | 36 +++++++++++++++++++++++++++---------
 src/dll/fuse/fuse.c      | 15 +++++++++++++++
 src/dll/fuse/fuse_main.c |  4 ++--
 4 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/inc/fuse/fuse_common.h b/inc/fuse/fuse_common.h
index c14e1c14..32a0040d 100644
--- a/inc/fuse/fuse_common.h
+++ b/inc/fuse/fuse_common.h
@@ -126,7 +126,8 @@ static inline int fuse_set_signal_handlers(struct fuse_session *se)
 
 static inline void fuse_remove_signal_handlers(struct fuse_session *se)
 {
-    fsp_fuse_remove_signal_handlers(se);
+    (void)se;
+    fsp_fuse_set_signal_handlers(0);
 }
 
 #ifdef __cplusplus
diff --git a/inc/fuse/winfsp_fuse.h b/inc/fuse/winfsp_fuse.h
index 75d4a614..80392aa5 100644
--- a/inc/fuse/winfsp_fuse.h
+++ b/inc/fuse/winfsp_fuse.h
@@ -19,6 +19,7 @@
 #ifndef FUSE_WINFSP_FUSE_H_INCLUDED
 #define FUSE_WINFSP_FUSE_H_INCLUDED
 
+#include <errno.h>
 #include <stdint.h>
 #if !defined(WINFSP_DLL_INTERNAL)
 #include <stdlib.h>
@@ -158,7 +159,6 @@ struct fuse_flock
         MemAlloc, MemFree,              \
         fsp_fuse_daemonize,             \
         fsp_fuse_set_signal_handlers,   \
-        fsp_fuse_remove_signal_handlers,\
     }
 #else
 #define FSP_FUSE_ENV_INIT               \
@@ -167,13 +167,12 @@ struct fuse_flock
         malloc, free,                   \
         fsp_fuse_daemonize,             \
         fsp_fuse_set_signal_handlers,   \
-        fsp_fuse_remove_signal_handlers,\
     }
 #endif
 
 #elif defined(__CYGWIN__)
 
-#include <errno.h>
+#include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/statvfs.h>
 #include <sys/types.h>
@@ -207,7 +206,6 @@ struct fuse_flock
         malloc, free,                   \
         fsp_fuse_daemonize,             \
         fsp_fuse_set_signal_handlers,   \
-        fsp_fuse_remove_signal_handlers,\
     }
 
 /*
@@ -226,9 +224,11 @@ struct fsp_fuse_env
     void (*memfree)(void *);
     int (*daemonize)(int);
     int (*set_signal_handlers)(void *);
-    void (*remove_signal_handlers)(void *);
 };
 
+FSP_FUSE_API void fsp_fuse_signal_handler(int sig);
+FSP_FUSE_API void fsp_fuse_set_signal_arg(void *se);
+
 static inline int fsp_fuse_daemonize(int foreground)
 {
 #if defined(_WIN64) || defined(_WIN32)
@@ -250,13 +250,31 @@ static inline int fsp_fuse_daemonize(int foreground)
 
 static inline int fsp_fuse_set_signal_handlers(void *se)
 {
+#if defined(_WIN64) || defined(_WIN32)
     (void)se;
     return 0;
-}
+#elif defined(__CYGWIN__)
 
-static inline void fsp_fuse_remove_signal_handlers(void *se)
-{
-    (void)se;
+#define FSP_FUSE_SET_SIGNAL_HANDLER(sig, newha)\
+    newsa.sa_handler = se ? (newha) : SIG_DFL;\
+    if (-1 == sigaction((sig), 0, &oldsa) ||\
+        (oldsa.sa_handler == (se ? SIG_DFL : (newha)) && -1 == sigaction((sig), &newsa, 0)))\
+        return -1;
+
+    struct sigaction oldsa, newsa = { 0 };
+
+    FSP_FUSE_SET_SIGNAL_HANDLER(SIGHUP, fsp_fuse_signal_handler);
+    FSP_FUSE_SET_SIGNAL_HANDLER(SIGINT, fsp_fuse_signal_handler);
+    FSP_FUSE_SET_SIGNAL_HANDLER(SIGTERM, fsp_fuse_signal_handler);
+    FSP_FUSE_SET_SIGNAL_HANDLER(SIGTERM, SIG_IGN);
+
+    fsp_fuse_set_signal_arg(se);
+
+    return 0;
+
+#undef FSP_FUSE_SET_SIGNAL_HANDLER
+
+#endif
 }
 
 static inline struct fsp_fuse_env *fsp_fuse_env(void)
diff --git a/src/dll/fuse/fuse.c b/src/dll/fuse/fuse.c
index afcc9168..ede7894d 100644
--- a/src/dll/fuse/fuse.c
+++ b/src/dll/fuse/fuse.c
@@ -661,3 +661,18 @@ FSP_FUSE_API int32_t fsp_fuse_ntstatus_from_errno(struct fsp_fuse_env *env,
             return STATUS_ACCESS_DENIED;
         }
 }
+
+/* Cygwin signal support */
+
+static struct fuse *fsp_fuse_signal_arg;
+
+FSP_FUSE_API void fsp_fuse_signal_handler(int sig)
+{
+    if (0 != fsp_fuse_signal_arg && 0 != fsp_fuse_signal_arg->Service)
+        FspServiceStop(fsp_fuse_signal_arg->Service);
+}
+
+FSP_FUSE_API void fsp_fuse_set_signal_arg(void *se)
+{
+    fsp_fuse_signal_arg = se;
+}
diff --git a/src/dll/fuse/fuse_main.c b/src/dll/fuse/fuse_main.c
index a53ae446..b72f0f00 100644
--- a/src/dll/fuse/fuse_main.c
+++ b/src/dll/fuse/fuse_main.c
@@ -153,7 +153,7 @@ FSP_FUSE_API int fsp_fuse_main_real(struct fsp_fuse_env *env,
     if (-1 == result)
         goto exit;
 
-    result = env->set_signal_handlers(f/* !!!: REVISIT */);
+    result = env->set_signal_handlers(f);
     if (-1 == result)
         goto exit;
     signal_handlers = 1;
@@ -162,7 +162,7 @@ FSP_FUSE_API int fsp_fuse_main_real(struct fsp_fuse_env *env,
 
 exit:
     if (signal_handlers)
-        env->remove_signal_handlers(f/* !!!: REVISIT */);
+        env->set_signal_handlers(0);
 
     if (0 != f)
         fsp_fuse_destroy(env, f);