1 files changed, 91 insertions, 0 deletions
diff --git a/libelf/elf_begin.c b/libelf/elf_begin.c
new file mode 100644
index 0000000000000..9f4f237aa9293
--- /dev/null
+++ b/libelf/elf_begin.c
@@ -0,0 +1,91 @@
+/*-
+ * Copyright (c) 2006,2008-2011 Joseph Koshy
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <libelf.h>
+
+#include "_libelf.h"
+
+ELFTC_VCSID("$Id: elf_begin.c 2364 2011-12-28 17:55:25Z jkoshy $");
+
+Elf *
+elf_begin(int fd, Elf_Cmd c, Elf *a)
+{
+	Elf *e;
+
+	e = NULL;
+
+	if (LIBELF_PRIVATE(version) == EV_NONE) {
+		LIBELF_SET_ERROR(SEQUENCE, 0);
+		return (NULL);
+	}
+
+	switch (c) {
+	case ELF_C_NULL:
+		return (NULL);
+
+	case ELF_C_WRITE:
+		/*
+		 * The ELF_C_WRITE command is required to ignore the
+		 * descriptor passed in.
+		 */
+		a = NULL;
+		break;
+
+	case ELF_C_RDWR:
+		if (a != NULL) { /* not allowed for ar(1) archives. */
+			LIBELF_SET_ERROR(ARGUMENT, 0);
+			return (NULL);
+		}
+		/*FALLTHROUGH*/
+	case ELF_C_READ:
+		/*
+		 * Descriptor `a' could be for a regular ELF file, or
+		 * for an ar(1) archive.  If descriptor `a' was opened
+		 * using a valid file descriptor, we need to check if
+		 * the passed in `fd' value matches the original one.
+		 */
+		if (a &&
+		    ((a->e_fd != -1 && a->e_fd != fd) || c != a->e_cmd)) {
+			LIBELF_SET_ERROR(ARGUMENT, 0);
+			return (NULL);
+		}
+		break;
+
+	default:
+		LIBELF_SET_ERROR(ARGUMENT, 0);
+		return (NULL);
+
+	}
+
+	if (a == NULL)
+		e = _libelf_open_object(fd, c, 1);
+	else if (a->e_kind == ELF_K_AR)
+		e = _libelf_ar_open_member(a->e_fd, c, a);
+	else
+		(e = a)->e_activations++;
+
+	return (e);
+}