Imported Upstream version 0.8.13upstream

1 files changed, 429 insertions, 0 deletions

diff --git a/lib/begin.c b/lib/begin.c
new file mode 100644
index 0000000..1a7a229
--- /dev/null
+++ b/lib/begin.c
@@ -0,0 +1,429 @@
+/*
+ * begin.c - implementation of the elf_begin(3) and elf_memory(3) functions.
+ * Copyright (C) 1995 - 2004 Michael Riepe
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <private.h>
+
+#ifndef lint
+static const char rcsid[] = "@(#) $Id: begin.c,v 1.22 2009/11/01 13:04:19 michael Exp $";
+#endif /* lint */
+
+static const Elf _elf_init = INIT_ELF;
+static const char fmag[] = ARFMAG;
+
+static unsigned long
+getnum(const char *str, size_t len, int base, size_t *err) {
+    unsigned long result = 0;
+
+    while (len && *str == ' ') {
+	str++; len--;
+    }
+    while (len && *str >= '0' && (*str - '0') < base) {
+	result = base * result + *str++ - '0'; len--;
+    }
+    while (len && *str == ' ') {
+	str++; len--;
+    }
+    if (len) {
+	*err = len;
+    }
+    return result;
+}
+
+static void
+_elf_init_ar(Elf *elf) {
+    struct ar_hdr *hdr;
+    size_t offset;
+    size_t size;
+    size_t err = 0;
+
+    elf->e_kind = ELF_K_AR;
+    elf->e_idlen = SARMAG;
+    elf->e_off = SARMAG;
+
+    /* process special members */
+    offset = SARMAG;
+    while (!elf->e_strtab && offset + sizeof(*hdr) <= elf->e_size) {
+	hdr = (struct ar_hdr*)(elf->e_data + offset);
+	if (memcmp(hdr->ar_fmag, fmag, sizeof(fmag) - 1)) {
+	    break;
+	}
+	if (hdr->ar_name[0] != '/') {
+	    break;
+	}
+	size = getnum(hdr->ar_size, sizeof(hdr->ar_size), 10, &err);
+	if (err || !size) {
+	    break;
+	}
+	offset += sizeof(*hdr);
+	if (offset + size > elf->e_size) {
+	    break;
+	}
+	if (hdr->ar_name[1] == '/' && hdr->ar_name[2] == ' ') {
+	    elf->e_strtab = elf->e_data + offset;
+	    elf->e_strlen = size;
+	    break;
+	}
+	if (hdr->ar_name[1] != ' ') {
+	    break;
+	}
+	/*
+	 * Windows (.lib) archives provide two symbol tables
+	 * The first one is the one we want.
+	 */
+	if (!elf->e_symtab) {
+	    elf->e_symtab = elf->e_data + offset;
+	    elf->e_symlen = size;
+	}
+	offset += size + (size & 1);
+    }
+}
+
+static Elf_Arhdr*
+_elf_arhdr(Elf *arf) {
+    struct ar_hdr *hdr;
+    Elf_Arhdr *arhdr;
+    size_t namelen;
+    size_t tmp;
+    char *name;
+    size_t err = 0;
+
+    if (arf->e_off == arf->e_size) {
+	/* no error! */
+	return NULL;
+    }
+    if (arf->e_off < 0 || arf->e_off > arf->e_size) {
+	seterr(ERROR_OUTSIDE);
+	return NULL;
+    }
+    if (arf->e_off + sizeof(*hdr) > arf->e_size) {
+	seterr(ERROR_TRUNC_ARHDR);
+	return NULL;
+    }
+    elf_assert(arf->e_data != NULL);
+    hdr = (struct ar_hdr*)(arf->e_data + arf->e_off);
+    if (memcmp(hdr->ar_fmag, fmag, sizeof(fmag) - 1)) {
+	seterr(ERROR_ARFMAG);
+	return NULL;
+    }
+
+    name = hdr->ar_name;
+    for (namelen = sizeof(hdr->ar_name); namelen > 0; namelen--) {
+	if (name[namelen - 1] != ' ') {
+	    break;
+	}
+    }
+    if (name[0] == '/') {
+	if (name[1] >= '0' && name[1] <= '9') {
+	    if (!arf->e_strtab) {
+		seterr(ERROR_ARSTRTAB);
+		return NULL;
+	    }
+	    tmp = getnum(&name[1], namelen - 1, 10, &err);
+	    if (err) {
+		seterr(ERROR_ARSPECIAL);
+		return NULL;
+	    }
+	    if (tmp < 0 || tmp >= arf->e_strlen) {
+		seterr(ERROR_ARSTRTAB);
+		return NULL;
+	    }
+	    for (namelen = tmp; namelen < arf->e_strlen; namelen++) {
+		if (arf->e_strtab[namelen] == '/') {
+		    break;
+		}
+	    }
+	    if (namelen == arf->e_strlen) {
+		seterr(ERROR_ARSTRTAB);
+		return NULL;
+	    }
+	    name = arf->e_strtab + tmp;
+	    namelen -= tmp;
+	}
+	else if (namelen != 1 && !(namelen == 2 && name[1] == '/')) {
+	    seterr(ERROR_ARSPECIAL);
+	    return NULL;
+	}
+    }
+    else if (namelen > 0 && name[namelen - 1] == '/') {
+	namelen--;
+    }
+    /* XXX some broken software omits the trailing slash
+    else {
+	namelen = 0;
+    }
+    */
+
+    if (!(arhdr = (Elf_Arhdr*)malloc(sizeof(*arhdr) +
+		     sizeof(hdr->ar_name) + namelen + 2))) {
+	seterr(ERROR_MEM_ARHDR);
+	return NULL;
+    }
+
+    arhdr->ar_name = NULL;
+    arhdr->ar_rawname = (char*)(arhdr + 1);
+    arhdr->ar_date = getnum(hdr->ar_date, sizeof(hdr->ar_date), 10, &err);
+    arhdr->ar_uid = getnum(hdr->ar_uid, sizeof(hdr->ar_uid), 10, &err);
+    arhdr->ar_gid = getnum(hdr->ar_gid, sizeof(hdr->ar_gid), 10, &err);
+    arhdr->ar_mode = getnum(hdr->ar_mode, sizeof(hdr->ar_mode), 8, &err);
+    arhdr->ar_size = getnum(hdr->ar_size, sizeof(hdr->ar_size), 10, &err);
+    if (err) {
+	free(arhdr);
+	seterr(ERROR_ARHDR);
+	return NULL;
+    }
+    if (arf->e_off + sizeof(struct ar_hdr) + arhdr->ar_size > arf->e_size) {
+	free(arhdr);
+	seterr(ERROR_TRUNC_MEMBER);
+	return NULL;
+    }
+
+    memcpy(arhdr->ar_rawname, hdr->ar_name, sizeof(hdr->ar_name));
+    arhdr->ar_rawname[sizeof(hdr->ar_name)] = '\0';
+
+    if (namelen) {
+	arhdr->ar_name = arhdr->ar_rawname + sizeof(hdr->ar_name) + 1;
+	memcpy(arhdr->ar_name, name, namelen);
+	arhdr->ar_name[namelen] = '\0';
+    }
+
+    return arhdr;
+}
+
+static void
+_elf_check_type(Elf *elf, size_t size) {
+    elf->e_idlen = size;
+    if (size >= EI_NIDENT && !memcmp(elf->e_data, ELFMAG, SELFMAG)) {
+	elf->e_kind = ELF_K_ELF;
+	elf->e_idlen = EI_NIDENT;
+	elf->e_class = elf->e_data[EI_CLASS];
+	elf->e_encoding = elf->e_data[EI_DATA];
+	elf->e_version = elf->e_data[EI_VERSION];
+    }
+    else if (size >= SARMAG && !memcmp(elf->e_data, ARMAG, SARMAG)) {
+	_elf_init_ar(elf);
+    }
+}
+
+Elf*
+elf_begin(int fd, Elf_Cmd cmd, Elf *ref) {
+    Elf_Arhdr *arhdr = NULL;
+    size_t size = 0;
+    off_t off;
+    Elf *elf;
+
+    elf_assert(_elf_init.e_magic == ELF_MAGIC);
+    if (_elf_version == EV_NONE) {
+	seterr(ERROR_VERSION_UNSET);
+	return NULL;
+    }
+    else if (cmd == ELF_C_NULL) {
+	return NULL;
+    }
+    else if (cmd == ELF_C_WRITE) {
+	ref = NULL;
+    }
+    else if (cmd != ELF_C_READ && cmd != ELF_C_RDWR) {
+	seterr(ERROR_INVALID_CMD);
+	return NULL;
+    }
+    else if (ref) {
+	elf_assert(ref->e_magic == ELF_MAGIC);
+	if (!ref->e_readable || (cmd == ELF_C_RDWR && !ref->e_writable)) {
+	    seterr(ERROR_CMDMISMATCH);
+	    return NULL;
+	}
+	if (ref->e_kind != ELF_K_AR) {
+	    ref->e_count++;
+	    return ref;
+	}
+	if (cmd == ELF_C_RDWR) {
+	    seterr(ERROR_MEMBERWRITE);
+	    return NULL;
+	}
+	if (ref->e_memory) {
+	    fd = ref->e_fd;
+	}
+	else if (fd != ref->e_fd) {
+	    seterr(ERROR_FDMISMATCH);
+	    return NULL;
+	}
+	if (!(arhdr = _elf_arhdr(ref))) {
+	    return NULL;
+	}
+	size = arhdr->ar_size;
+    }
+    else if ((off = lseek(fd, (off_t)0, SEEK_END)) == (off_t)-1
+	  || (off_t)(size = off) != off) {
+	seterr(ERROR_IO_GETSIZE);
+	return NULL;
+    }
+
+    if (!(elf = (Elf*)malloc(sizeof(Elf)))) {
+	seterr(ERROR_MEM_ELF);
+	return NULL;
+    }
+    *elf = _elf_init;
+    elf->e_fd = fd;
+    elf->e_parent = ref;
+    elf->e_size = elf->e_dsize = size;
+
+    if (cmd != ELF_C_READ) {
+	elf->e_writable = 1;
+    }
+    if (cmd != ELF_C_WRITE) {
+	elf->e_readable = 1;
+    }
+    else {
+	return elf;
+    }
+
+    if (ref) {
+	size_t offset = ref->e_off + sizeof(struct ar_hdr);
+	Elf *xelf;
+
+	elf_assert(arhdr);
+	elf->e_arhdr = arhdr;
+	elf->e_base = ref->e_base + offset;
+	/*
+	 * Share the archive's memory image. To avoid
+	 * multiple independent elf descriptors if the
+	 * same member is requested twice, scan the list
+	 * of open members for duplicates.
+	 *
+	 * I don't know how SVR4 handles this case. Don't rely on it.
+	 */
+	for (xelf = ref->e_members; xelf; xelf = xelf->e_link) {
+	    elf_assert(xelf->e_parent == ref);
+	    if (xelf->e_base == elf->e_base) {
+		free(arhdr);
+		free(elf);
+		xelf->e_count++;
+		return xelf;
+	    }
+	}
+	if (size == 0) {
+	    elf->e_data = NULL;
+	}
+#if 1
+	else {
+	    /*
+	     * Archive members may be misaligned.  Freezing them will
+	     * cause libelf to allocate buffers for translated data,
+	     * which should be properly aligned in all cases.
+	     */
+	    elf_assert(!ref->e_cooked);
+	    elf->e_data = elf->e_rawdata = ref->e_data + offset;
+	}
+#else
+	else if (ref->e_data == ref->e_rawdata) {
+	    elf_assert(!ref->e_cooked);
+	    /*
+	     * archive is frozen - freeze member, too
+	     */
+	    elf->e_data = elf->e_rawdata = ref->e_data + offset;
+	}
+	else {
+	    elf_assert(!ref->e_memory);
+	    elf->e_data = ref->e_data + offset;
+	    /*
+	     * The member's memory image may have been modified if
+	     * the member has been processed before. Since we need the
+	     * original image, we have to re-read the archive file.
+	     * Will fail if the archive's file descriptor is disabled.
+	     */
+	    if (!ref->e_cooked) {
+		ref->e_cooked = 1;
+	    }
+	    else if (!_elf_read(ref, elf->e_data, offset, size)) {
+		free(arhdr);
+		free(elf);
+		return NULL;
+	    }
+	}
+#endif
+	elf->e_next = offset + size + (size & 1);
+	elf->e_disabled = ref->e_disabled;
+	elf->e_memory = ref->e_memory;
+	/* parent/child linking */
+	elf->e_link = ref->e_members;
+	ref->e_members = elf;
+	ref->e_count++;
+	/* Slowaris compatibility - do not rely on this! */
+	ref->e_off = elf->e_next;
+    }
+    else if (size) {
+#if HAVE_MMAP
+	/*
+	 * Using mmap on writable files will interfere with elf_update
+	 */
+	if (!elf->e_writable && (elf->e_data = _elf_mmap(elf))) {
+	    elf->e_unmap_data = 1;
+	}
+	else
+#endif /* HAVE_MMAP */
+	if (!(elf->e_data = _elf_read(elf, NULL, 0, size))) {
+	    free(elf);
+	    return NULL;
+	}
+    }
+
+    _elf_check_type(elf, size);
+    return elf;
+}
+
+Elf*
+elf_memory(char *image, size_t size) {
+    Elf *elf;
+
+    elf_assert(_elf_init.e_magic == ELF_MAGIC);
+    if (_elf_version == EV_NONE) {
+	seterr(ERROR_VERSION_UNSET);
+	return NULL;
+    }
+    else if (size == 0 || image == NULL) {
+	/* TODO: set error code? */
+	return NULL;
+    }
+
+    if (!(elf = (Elf*)malloc(sizeof(Elf)))) {
+	seterr(ERROR_MEM_ELF);
+	return NULL;
+    }
+    *elf = _elf_init;
+    elf->e_size = elf->e_dsize = size;
+    elf->e_data = elf->e_rawdata = image;
+    elf->e_readable = 1;
+    elf->e_disabled = 1;
+    elf->e_memory = 1;
+
+    _elf_check_type(elf, size);
+    return elf;
+}
+
+#if __LIBELF64
+
+int
+gelf_getclass(Elf *elf) {
+    if (elf && elf->e_kind == ELF_K_ELF && valid_class(elf->e_class)) {
+	return elf->e_class;
+    }
+    return ELFCLASSNONE;
+}
+
+#endif /* __LIBELF64 */