ext/libelf/libelf_allocate.c

/*-
 * 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.
 */

/*
 * Internal APIs
 */

#include <errno.h>

#include <assert.h>
#include "libelf.h"
#include <stdlib.h>
#include <string.h>

#include "_libelf.h"

Elf *
_libelf_allocate_elf(void)
{
        Elf *e;

        if ((e = malloc(sizeof(*e))) == NULL) {
                LIBELF_SET_ERROR(RESOURCE, errno);
                return NULL;
        }

        e->e_activations = 1;
        e->e_arhdr	 = NULL;
        e->e_byteorder   = ELFDATANONE;
        e->e_class       = ELFCLASSNONE;
        e->e_cmd         = ELF_C_NULL;
        e->e_fd          = -1;
        e->e_flags	 = 0;
        e->e_kind        = ELF_K_NONE;
        e->e_parent      = NULL;
        e->e_rawfile     = NULL;
        e->e_rawsize     = 0;
        e->e_version     = LIBELF_PRIVATE(version);

        (void) memset(&e->e_u, 0, sizeof(e->e_u));

        return (e);
}

void
_libelf_init_elf(Elf *e, Elf_Kind kind)
{
        assert(e != NULL);
        assert(e->e_kind == ELF_K_NONE);

        e->e_kind = kind;

        switch (kind) {
        case ELF_K_ELF:
                STAILQ_INIT(&e->e_u.e_elf.e_scn);
                break;
        default:
                break;
        }
}

#define	FREE(P)		do {				\
                if (P)					\
                        free(P);			\
        } while (0)


Elf *
_libelf_release_elf(Elf *e)
{
        switch (e->e_kind) {
        case ELF_K_AR:
                FREE(e->e_u.e_ar.e_symtab);
                break;

        case ELF_K_ELF:
                switch (e->e_class) {
                case ELFCLASS32:
                        FREE(e->e_u.e_elf.e_ehdr.e_ehdr32);
                        FREE(e->e_u.e_elf.e_phdr.e_phdr32);
                        break;
                case ELFCLASS64:
                        FREE(e->e_u.e_elf.e_ehdr.e_ehdr64);
                        FREE(e->e_u.e_elf.e_phdr.e_phdr64);
                        break;
                }

                assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn));

                if (e->e_arhdr) {
                        FREE(e->e_arhdr->ar_name);
                        FREE(e->e_arhdr->ar_rawname);
                        free(e->e_arhdr);
                }

                break;

        default:
                break;
        }

        free(e);

        return (NULL);
}

Elf_Data *
_libelf_allocate_data(Elf_Scn *s)
{
        Elf_Data *d;

        if ((d = calloc((size_t) 1, sizeof(Elf_Data))) == NULL) {
                LIBELF_SET_ERROR(RESOURCE, 0);
                return (NULL);
        }

        d->d_scn = s;

        return (d);
}

Elf_Data *
_libelf_release_data(Elf_Data *d)
{

        if (d->d_flags & LIBELF_F_MALLOCED)
                free(d->d_buf);

        free(d);

        return (NULL);
}

Elf_Scn *
_libelf_allocate_scn(Elf *e, size_t ndx)
{
        Elf_Scn *s;

        if ((s = calloc((size_t) 1, sizeof(Elf_Scn))) == NULL) {
                LIBELF_SET_ERROR(RESOURCE, errno);
                return (NULL);
        }

        s->s_elf = e;
        s->s_ndx = ndx;

        STAILQ_INIT(&s->s_data);
        STAILQ_INIT(&s->s_rawdata);

        STAILQ_INSERT_TAIL(&e->e_u.e_elf.e_scn, s, s_next);

        return (s);
}

Elf_Scn *
_libelf_release_scn(Elf_Scn *s)
{
        Elf *e;
        Elf_Data *d, *td;

        assert(s != NULL);

        STAILQ_FOREACH_SAFE(d, &s->s_data, d_next, td) {
                STAILQ_REMOVE(&s->s_data, d, _Elf_Data, d_next);
                d = _libelf_release_data(d);
        }

        STAILQ_FOREACH_SAFE(d, &s->s_rawdata, d_next, td) {
                assert((d->d_flags & LIBELF_F_MALLOCED) == 0);
                STAILQ_REMOVE(&s->s_rawdata, d, _Elf_Data, d_next);
                d = _libelf_release_data(d);
        }

        e = s->s_elf;

        assert(e != NULL);

        STAILQ_REMOVE(&e->e_u.e_elf.e_scn, s, _Elf_Scn, s_next);

        free(s);

        return (NULL);
}