[Feature] Add utility to map shared memory segments

2 files changed, 51 insertions, 0 deletions

diff --git a/src/libutil/util.c b/src/libutil/util.c
index cf6101e4d..f3effe5cf 100644
--- a/src/libutil/util.c
+++ b/src/libutil/util.c
@@ -2276,3 +2276,44 @@ rspamd_file_xmap (const char *fname, guint mode,
 
 	return map;
 }
+
+
+gpointer
+rspamd_shmem_xmap (const char *fname, guint mode,
+		gsize *size)
+{
+	gint fd;
+	struct stat sb;
+	gpointer map;
+
+	g_assert (fname != NULL);
+	g_assert (size != NULL);
+
+	if (mode & PROT_WRITE) {
+		fd = shm_open (fname, O_RDWR, 0);
+	}
+	else {
+		fd = shm_open (fname, O_RDONLY, 0);
+	}
+
+	if (fd == -1) {
+		return NULL;
+	}
+
+	if (fstat (fd, &sb) == -1) {
+		close (fd);
+
+		return NULL;
+	}
+
+	map = mmap (NULL, sb.st_size, mode, MAP_SHARED, fd, 0);
+	close (fd);
+
+	if (map == MAP_FAILED) {
+		return NULL;
+	}
+
+	*size = sb.st_size;
+
+	return map;
+}
diff --git a/src/libutil/util.h b/src/libutil/util.h
index 0c293ccbe..2497d538f 100644
--- a/src/libutil/util.h
+++ b/src/libutil/util.h
@@ -463,4 +463,14 @@ int rspamd_file_xopen (const char *fname, int oflags, guint mode);
 gpointer rspamd_file_xmap (const char *fname, guint mode,
 		gsize *size);
 
+/**
+ * Map named shared memory segment
+ * @param fname filename
+ * @param mode mode to open
+ * @param size target size (must NOT be NULL)
+ * @return pointer to memory (should be freed using munmap) or NULL in case of error
+ */
+gpointer rspamd_shmem_xmap (const char *fname, guint mode,
+		gsize *size);
+
 #endif