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-rw-r--r--ext/libelf/elf_begin.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/ext/libelf/elf_begin.c b/ext/libelf/elf_begin.c
new file mode 100644
index 000000000..1ffd26651
--- /dev/null
+++ b/ext/libelf/elf_begin.c
@@ -0,0 +1,154 @@
+/*-
+ * Copyright (c) 2006 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 <sys/types.h>
+#include <sys/errno.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <ar.h>
+#include <ctype.h>
+#include "libelf.h"
+
+#include "_libelf.h"
+
+static Elf *
+_libelf_open_object(int fd, Elf_Cmd c)
+{
+ Elf *e;
+ void *m;
+ struct stat sb;
+
+ /*
+ * 'Raw' files are always mapped with 'PROT_READ'. At
+ * elf_update(3) time for files opened with ELF_C_RDWR the
+ * mapping is unmapped, file data is written to using write(2)
+ * and then the raw data is immediately mapped back in.
+ */
+ if (fstat(fd, &sb) < 0) {
+ LIBELF_SET_ERROR(IO, errno);
+ return (NULL);
+ }
+
+ m = NULL;
+ if ((m = mmap(NULL, (size_t) sb.st_size, PROT_READ, MAP_PRIVATE, fd,
+ (off_t) 0)) == MAP_FAILED) {
+ LIBELF_SET_ERROR(IO, errno);
+ return (NULL);
+ }
+
+ if ((e = elf_memory(m, (size_t) sb.st_size)) == NULL) {
+ (void) munmap(m, (size_t) sb.st_size);
+ return (NULL);
+ }
+
+ e->e_flags |= LIBELF_F_MMAP;
+ e->e_fd = fd;
+ e->e_cmd = c;
+
+ if (c == ELF_C_RDWR && e->e_kind == ELF_K_AR) {
+ (void) elf_end(e);
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return (NULL);
+ }
+
+ return (e);
+}
+
+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:
+
+ if (a != NULL) { /* not allowed for ar(1) archives. */
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return (NULL);
+ }
+
+ /*
+ * Check writeability of `fd' immediately and fail if
+ * not writeable.
+ */
+ if (ftruncate(fd, (off_t) 0) < 0) {
+ LIBELF_SET_ERROR(IO, errno);
+ return (NULL);
+ }
+
+ if ((e = _libelf_allocate_elf()) != NULL) {
+ _libelf_init_elf(e, ELF_K_ELF);
+ e->e_byteorder = LIBELF_PRIVATE(byteorder);
+ e->e_fd = fd;
+ e->e_cmd = c;
+ }
+ return (e);
+
+ 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 (a && (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);
+ else if (a->e_kind == ELF_K_AR)
+ e = _libelf_ar_open_member(fd, c, a);
+ else
+ (e = a)->e_activations++;
+
+ return (e);
+}