freebsd-skq/usr.sbin/kgzip/kgzcmp.c

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/*
* Copyright (c) 1999 Global Technology Associates, Inc.
* 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.
*
* $Id:$
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <a.out.h>
#include <elf.h>
#include "elfhdr.h"
#include "kgzip.h"
#define KGZOFF (sizeof(struct kgz_elfhdr) + sizeof(struct kgz_hdr))
#define F_AOUT 1 /* Input format: a.out */
#define F_ELF 2 /* Input format: ELF32 */
static void mk_data(const struct iodesc *i, const struct iodesc *,
struct kgz_hdr *);
static int ld_elf(const struct iodesc *, const struct iodesc *,
struct kgz_hdr *, const Elf32_Ehdr *);
static int ld_aout(const struct iodesc *, const struct iodesc *,
struct kgz_hdr *, const struct exec *);
/*
* Compress executable and output it in relocatable object format.
*/
void
kgzcmp(struct kgz_hdr *kh, const char *f1, const char *f2)
{
struct iodesc idi, ido;
struct kgz_elfhdr ehdr;
if ((idi.fd = open(idi.fname = f1, O_RDONLY)) == -1)
err(1, "%s", idi.fname);
if ((ido.fd = open(ido.fname = f2, O_CREAT | O_TRUNC | O_WRONLY,
0666)) == -1)
err(1, "%s", ido.fname);
kh->ident[0] = KGZ_ID0;
kh->ident[1] = KGZ_ID1;
kh->ident[2] = KGZ_ID2;
kh->ident[3] = KGZ_ID3;
xseek(&ido, KGZOFF);
mk_data(&idi, &ido, kh);
kh->dload &= 0xffffff;
kh->entry &= 0xffffff;
xseek(&ido, 0);
ehdr = elfhdr;
ehdr.st[KGZ_ST_KGZ_NDATA].st_size = kh->nsize;
ehdr.sh[KGZ_SH_DATA].sh_size += kh->nsize;
xwrite(&ido, &ehdr, sizeof(ehdr));
xwrite(&ido, kh, sizeof(*kh));
xclose(&ido);
xclose(&idi);
}
/*
* Make encoded (compressed) data.
*/
static void
mk_data(const struct iodesc * idi, const struct iodesc * ido,
struct kgz_hdr * kh)
{
union {
struct exec ex;
Elf32_Ehdr ee;
} hdr;
struct stat sb;
struct iodesc idp;
int fd[2];
pid_t pid;
size_t n;
int fmt, status, e;
n = xread(idi, &hdr, sizeof(hdr), 0);
fmt = 0;
if (n >= sizeof(hdr.ee) && IS_ELF(hdr.ee))
fmt = F_ELF;
else if (n >= sizeof(hdr.ex) && N_GETMAGIC(hdr.ex) == ZMAGIC)
fmt = F_AOUT;
if (!fmt)
errx(1, "%s: Format not supported", idi->fname);
if (pipe(fd))
err(1, NULL);
switch (pid = fork()) {
case -1:
err(1, NULL);
case 0:
close(fd[1]);
dup2(fd[0], STDIN_FILENO);
close(fd[0]);
close(idi->fd);
dup2(ido->fd, STDOUT_FILENO);
close(ido->fd);
execlp("gzip", "gzip", "-9", NULL);
warn(NULL);
_exit(1);
default:
close(fd[0]);
idp.fname = "(pipe)";
idp.fd = fd[1];
e = fmt == F_ELF ? ld_elf(idi, &idp, kh, &hdr.ee) :
fmt == F_AOUT ? ld_aout(idi, &idp, kh, &hdr.ex) : -1;
close(fd[1]);
if ((pid = waitpid(pid, &status, 0)) == -1)
err(1, NULL);
if (WIFSIGNALED(status) || WEXITSTATUS(status))
exit(1);
}
if (e)
errx(1, "%s: Invalid format", idi->fname);
if (fstat(ido->fd, &sb))
err(1, ido->fname);
kh->nsize = sb.st_size - KGZOFF;
}
/*
* "Load" an ELF-format executable.
*/
static int
ld_elf(const struct iodesc * idi, const struct iodesc * ido,
struct kgz_hdr * kh, const Elf32_Ehdr * e)
{
Elf32_Phdr p;
size_t load, addr, n;
unsigned x, i;
load = addr = n = 0;
for (x = i = 0; i < e->e_phnum; i++) {
if (xread(idi, &p, sizeof(p),
e->e_phoff + i * e->e_phentsize) != e->e_phentsize)
return -1;
if (p.p_type != PT_LOAD)
continue;
if (!x)
load = addr = p.p_vaddr;
else {
if (p.p_vaddr < addr)
return -1;
n = p.p_vaddr - addr;
if (n) {
xzero(ido, n);
addr += n;
}
}
if (p.p_memsz < p.p_filesz)
return -1;
n = p.p_memsz - p.p_filesz;
xcopy(idi, ido, p.p_filesz, p.p_offset);
addr += p.p_filesz;
x++;
}
if (!x)
return -1;
kh->dload = load;
kh->dsize = addr - load;
kh->isize = kh->dsize + n;
kh->entry = e->e_entry;
return 0;
}
/*
* "Load" an a.out-format executable.
*/
static int
ld_aout(const struct iodesc * idi, const struct iodesc * ido,
struct kgz_hdr * kh, const struct exec * a)
{
size_t load, addr;
load = addr = N_TXTADDR(*a);
xcopy(idi, ido, a->a_text, N_TXTOFF(*a));
addr += a->a_text;
if (N_DATADDR(*a) != addr)
return -1;
xcopy(idi, ido, a->a_data, N_DATOFF(*a));
addr += a->a_data;
kh->dload = load;
kh->dsize = addr - load;
kh->isize = kh->dsize + a->a_bss;
kh->entry = a->a_entry;
return 0;
}