1 files changed, 272 insertions, 0 deletions
diff --git a/lib/libelf/libelf_ar.c b/lib/libelf/libelf_ar.c
new file mode 100644
index 0000000..7322617
--- /dev/null
+++ b/lib/libelf/libelf_ar.c
@@ -0,0 +1,272 @@
+/*-
+ * 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/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <ar.h>
+#include <assert.h>
+#include <ctype.h>
+#include <libelf.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "_libelf.h"
+
+#define	LIBELF_NALLOC_SIZE	16
+
+/*
+ * `ar' archive handling.
+ *
+ * `ar' archives start with signature `ARMAG'.  Each archive member is
+ * preceded by a header containing meta-data for the member.  This
+ * header is described in <ar.h> (struct ar_hdr).  The header always
+ * starts on an even address.  File data is padded with "\n"
+ * characters to keep this invariant.
+ *
+ * Special considerations for `ar' archives:
+ *
+ * The `ar' header only has space for a 16 character file name.  File
+ * names are terminated with a '/', so this effectively leaves 15
+ * characters for the actual file name.  In order to accomodate longer
+ * file names, names may be stored in a separate 'string table' and
+ * referenced indirectly by a member header.  The string table itself
+ * appears as an archive member with name "// ".  An indirect file name
+ * in an `ar' header matches the pattern "/[0-9]*". The digits form a
+ * decimal number that corresponds to a byte offset into the string
+ * table where the actual file name of the object starts.  Strings in
+ * the string table are padded to start on even addresses.
+ *
+ * Archives may also have a symbol table (see ranlib(1)), mapping
+ * program symbols to object files inside the archive.  A symbol table
+ * uses a file name of "/ " in its archive header.  The symbol table
+ * is structured as:
+ *  - a 4-byte count of entries stored as a binary value, MSB first
+ *  - 'n' 4-byte offsets, stored as binary values, MSB first
+ *  - 'n' NUL-terminated strings, for ELF symbol names, stored unpadded.
+ *
+ * If the symbol table and string table are is present in an archive
+ * they must be the very first objects and in that order.
+ */
+
+
+
+Elf_Arhdr *
+_libelf_ar_gethdr(Elf *e)
+{
+	Elf *parent;
+	struct ar_hdr *arh;
+	Elf_Arhdr *eh;
+	size_t n;
+
+	if ((parent = e->e_parent) == NULL) {
+		LIBELF_SET_ERROR(ARGUMENT, 0);
+		return (NULL);
+	}
+
+	arh = (struct ar_hdr *) ((uintptr_t) e->e_rawfile - sizeof(struct ar_hdr));
+
+	assert((uintptr_t) arh >= (uintptr_t) parent->e_rawfile + SARMAG);
+	assert((uintptr_t) arh <= (uintptr_t) parent->e_rawfile + parent->e_rawsize -
+	    sizeof(struct ar_hdr));
+
+	if ((eh = malloc(sizeof(Elf_Arhdr))) == NULL) {
+		LIBELF_SET_ERROR(RESOURCE, 0);
+		return (NULL);
+	}
+
+	e->e_arhdr = eh;
+	eh->ar_name = eh->ar_rawname = NULL;
+
+	if ((eh->ar_name = _libelf_ar_get_name(arh->ar_name, sizeof(arh->ar_name),
+		 parent)) == NULL)
+		goto error;
+
+	if (_libelf_ar_get_number(arh->ar_uid, sizeof(arh->ar_uid), 10, &n) == 0)
+		goto error;
+	eh->ar_uid = (uid_t) n;
+
+	if (_libelf_ar_get_number(arh->ar_gid, sizeof(arh->ar_gid), 10, &n) == 0)
+		goto error;
+	eh->ar_gid = (gid_t) n;
+
+	if (_libelf_ar_get_number(arh->ar_mode, sizeof(arh->ar_mode), 8, &n) == 0)
+		goto error;
+	eh->ar_mode = (mode_t) n;
+
+	if (_libelf_ar_get_number(arh->ar_size, sizeof(arh->ar_size), 10, &n) == 0)
+		goto error;
+	eh->ar_size = n;
+
+	if ((eh->ar_rawname = _libelf_ar_get_string(arh->ar_name,
+		 sizeof(arh->ar_name), 1)) == NULL)
+		goto error;
+
+	return (eh);
+
+ error:
+	if (eh) {
+		if (eh->ar_name)
+			free(eh->ar_name);
+		if (eh->ar_rawname)
+			free(eh->ar_rawname);
+		free(eh);
+	}
+	e->e_arhdr = NULL;
+
+	return (NULL);
+}
+
+Elf *
+_libelf_ar_open_member(int fd, Elf_Cmd c, Elf *elf)
+{
+	Elf *e;
+	off_t next;
+	struct ar_hdr *arh;
+	size_t sz;
+
+	assert(elf->e_kind == ELF_K_AR);
+
+	next = elf->e_u.e_ar.e_next;
+
+	/*
+	 * `next' is only set to zero by elf_next() when the last
+	 * member of an archive is processed.
+	 */
+	if (next == (off_t) 0)
+		return (NULL);
+
+	assert((next & 1) == 0);
+
+	arh = (struct ar_hdr *) (elf->e_rawfile + next);
+
+	if (_libelf_ar_get_number(arh->ar_size, sizeof(arh->ar_size), 10, &sz) == 0) {
+		LIBELF_SET_ERROR(ARCHIVE, 0);
+		return (NULL);
+	}
+
+	assert(sz > 0);
+
+	arh++;	/* skip over archive member header */
+
+	if ((e = elf_memory((char *) arh, sz)) == NULL)
+		return (NULL);
+
+	e->e_fd = fd;
+	e->e_cmd = c;
+
+	elf->e_u.e_ar.e_nchildren++;
+	e->e_parent = elf;
+
+	return (e);
+}
+
+/*
+ * An ar(1) symbol table has the following layout:
+ *
+ * The first 4 bytes are a binary count of the number of entries in the
+ * symbol table, stored MSB-first.
+ *
+ * Then there are 'n' 4-byte binary offsets, also stored MSB first.
+ *
+ * Following this, there are 'n' null-terminated strings.
+ */
+
+#define	GET_WORD(P, V) do {			\
+		(V) = 0;			\
+		(V) = (P)[0]; (V) <<= 8;	\
+		(V) += (P)[1]; (V) <<= 8;	\
+		(V) += (P)[2]; (V) <<= 8;	\
+		(V) += (P)[3];			\
+	} while (0)
+
+#define	INTSZ	4
+
+Elf_Arsym *
+_libelf_ar_process_symtab(Elf *e, size_t *count)
+{
+	size_t n, nentries, off;
+	Elf_Arsym *symtab, *sym;
+	unsigned char  *p, *s, *end;
+
+	assert(e != NULL);
+	assert(count != NULL);
+
+	if (e->e_u.e_ar.e_rawsymtabsz < INTSZ) {
+		LIBELF_SET_ERROR(ARCHIVE, 0);
+		return (NULL);
+	}
+
+	p = (unsigned char *) e->e_u.e_ar.e_rawsymtab;
+	end = p + e->e_u.e_ar.e_rawsymtabsz;
+
+	GET_WORD(p, nentries);
+	p += INTSZ;
+
+	if (nentries == 0 || p + nentries * INTSZ >= end) {
+		LIBELF_SET_ERROR(ARCHIVE, 0);
+		return (NULL);
+	}
+
+	/* Allocate space for a nentries + a sentinel. */
+	if ((symtab = malloc(sizeof(Elf_Arsym) * (nentries+1))) == NULL) {
+		LIBELF_SET_ERROR(RESOURCE, 0);
+		return (NULL);
+	}
+
+	s = p + (nentries * INTSZ); /* start of the string table. */
+
+	for (n = nentries, sym = symtab; n > 0; n--) {
+		off = 0;
+
+		GET_WORD(p, off);
+
+		sym->as_off = off;
+		sym->as_hash = elf_hash(s);
+		sym->as_name = s;
+
+		p += INTSZ;
+		sym++;
+
+		for (; s < end && *s++ != '\0';) /* skip to next string */
+			;
+		if (s > end) {
+			LIBELF_SET_ERROR(ARCHIVE, 0);
+			free(symtab);
+			return (NULL);
+		}
+	}
+
+	/* Fill up the sentinel entry. */
+	sym->as_name = NULL;
+	sym->as_hash = ~0UL;
+	sym->as_off = (off_t) 0;
+
+	*count = e->e_u.e_ar.e_symtabsz = nentries + 1;
+	e->e_u.e_ar.e_symtab = symtab;
+
+	return (symtab);
+}