1 files changed, 199 insertions, 0 deletions
diff --git a/compat/shm.cpp b/compat/shm.cpp
new file mode 100644
index 00000000..83a3260c
--- /dev/null
+++ b/compat/shm.cpp
@@ -0,0 +1,199 @@
+/* Copyright (c) 2013 Stanislaw Halik <sthalik@misaki.pl>
+
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#include "shm.h"
+
+#if defined(_WIN32)
+
+#include <cstring>
+#include <stdio.h>
+
+#include <accctrl.h>
+#include <aclapi.h>
+
+struct secattr
+{
+    bool success;
+    SECURITY_DESCRIPTOR* pSD;
+    SECURITY_ATTRIBUTES attrs;
+    PSID pEveryoneSID;
+    PACL pACL;
+
+    void cleanup()
+    {
+        if (pEveryoneSID)
+            FreeSid(pEveryoneSID);
+        if (pACL)
+            LocalFree(pACL);
+        if (pSD)
+            LocalFree(pSD);
+        success = false;
+        pSD = nullptr;
+        pEveryoneSID = nullptr;
+        pACL = nullptr;
+    }
+
+    secattr(DWORD perms) : success(true), pSD(nullptr), pEveryoneSID(nullptr), pACL(nullptr)
+    {
+        SID_IDENTIFIER_AUTHORITY SIDAuthWorld = SECURITY_WORLD_SID_AUTHORITY;
+        EXPLICIT_ACCESS ea;
+
+        if(!AllocateAndInitializeSid(&SIDAuthWorld, 1,
+                         SECURITY_WORLD_RID,
+                         0, 0, 0, 0, 0, 0, 0,
+                         &pEveryoneSID))
+        {
+            fprintf(stderr, "AllocateAndInitializeSid: %d\n", (int) GetLastError());
+            goto cleanup;
+        }
+
+        memset(&ea, 0, sizeof(ea));
+
+        ea.grfAccessPermissions = perms;
+        ea.grfAccessMode = SET_ACCESS;
+        ea.grfInheritance = NO_INHERITANCE;
+        ea.Trustee.TrusteeForm = TRUSTEE_IS_SID;
+        ea.Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
+        ea.Trustee.ptstrName  = (LPTSTR) pEveryoneSID;
+
+        if (SetEntriesInAcl(1, &ea, NULL, &pACL) != ERROR_SUCCESS)
+        {
+            fprintf(stderr, "SetEntriesInAcl: %d\n", (int) GetLastError());
+            goto cleanup;
+        }
+
+        pSD = (SECURITY_DESCRIPTOR*) LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH);
+        if (pSD == nullptr)
+        {
+            fprintf(stderr, "LocalAlloc: %d\n", (int) GetLastError());
+            goto cleanup;
+        }
+
+        if (!InitializeSecurityDescriptor(pSD,
+                    SECURITY_DESCRIPTOR_REVISION))
+        {
+            fprintf(stderr, "InitializeSecurityDescriptor: %d\n", (int) GetLastError());
+            goto cleanup;
+        }
+
+        if (!SetSecurityDescriptorDacl(pSD,
+                                       TRUE,
+                                       pACL,
+                                       FALSE))
+        {
+            fprintf(stderr, "SetSecurityDescriptorDacl: %d\n", (int) GetLastError());
+            goto cleanup;
+        }
+
+        attrs.bInheritHandle = false;
+        attrs.lpSecurityDescriptor = pSD;
+        attrs.nLength = sizeof(SECURITY_ATTRIBUTES);
+
+        fflush(stderr);
+
+        return;
+cleanup:
+        fflush(stderr);
+        cleanup();
+    }
+
+    ~secattr()
+    {
+        cleanup();
+    }
+};
+
+PortableLockedShm::PortableLockedShm(const char* shmName, const char* mutexName, int mapSize)
+{
+    secattr sa(GENERIC_ALL|SYNCHRONIZE);
+
+    hMutex = CreateMutexA(sa.success ? &sa.attrs : nullptr, false, mutexName);
+    if (!hMutex)
+    {
+        fprintf(stderr, "CreateMutexA: %d\n", (int) GetLastError());
+        fflush(stderr);
+    }
+    hMapFile = CreateFileMappingA(
+                 INVALID_HANDLE_VALUE,
+                 sa.success ? &sa.attrs : nullptr,
+                 PAGE_READWRITE,
+                 0,
+                 mapSize,
+                 shmName);
+    if (!hMapFile)
+    {
+        fprintf(stderr, "CreateFileMappingA: %d\n", (int) GetLastError());
+        fflush(stderr);
+    }
+    mem = MapViewOfFile(hMapFile,
+                        FILE_MAP_WRITE,
+                        0,
+                        0,
+                        mapSize);
+    if (!mem)
+    {
+        fprintf(stderr, "MapViewOfFile: %d\n", (int) GetLastError());
+        fflush(stderr);
+    }
+}
+
+PortableLockedShm::~PortableLockedShm()
+{
+    UnmapViewOfFile(mem);
+    CloseHandle(hMapFile);
+    CloseHandle(hMutex);
+}
+
+void PortableLockedShm::lock()
+{
+    (void) WaitForSingleObject(hMutex, INFINITE);
+}
+
+void PortableLockedShm::unlock()
+{
+    (void) ReleaseMutex(hMutex);
+}
+#else
+
+#include <limits.h>
+
+#pragma GCC diagnostic ignored "-Wunused-result"
+PortableLockedShm::PortableLockedShm(const char *shmName, const char* /*mutexName*/, int mapSize) : size(mapSize)
+{
+    char filename[PATH_MAX+2] = {0};
+    strcpy(filename, "/");
+    strcat(filename, shmName);
+    fd = shm_open(filename, O_RDWR | O_CREAT, 0600);
+    (void) ftruncate(fd, mapSize);
+    mem = mmap(NULL, mapSize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, (off_t)0);
+}
+
+PortableLockedShm::~PortableLockedShm()
+{
+    (void) munmap(mem, size);
+    (void) close(fd);
+}
+
+void PortableLockedShm::lock()
+{
+    flock(fd, LOCK_EX);
+}
+
+void PortableLockedShm::unlock()
+{
+    flock(fd, LOCK_UN);
+}
+#endif
+
+bool PortableLockedShm::success()
+{
+#ifndef _WIN32
+    return mem != (void*) -1;
+#else
+    return mem != NULL;
+#endif
+}