/* archive.c - Alpine Package Keeper (APK)
*
* Copyright (C) 2005-2008 Natanael Copa <n@tanael.org>
* Copyright (C) 2008 Timo Teräs <timo.teras@iki.fi>
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation. See http://www.gnu.org/ for details.
*/
#include <stdio.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <malloc.h>
#include <string.h>
#include <unistd.h>
#include <sysexits.h>
#include <sys/wait.h>
#include "apk_defines.h"
#include "apk_archive.h"
#ifndef GUNZIP_BINARY
#define GUNZIP_BINARY "/bin/gunzip"
#endif
struct tar_header {
/* ustar header, Posix 1003.1 */
char name[100]; /* 0-99 */
char mode[8]; /* 100-107 */
char uid[8]; /* 108-115 */
char gid[8]; /* 116-123 */
char size[12]; /* 124-135 */
char mtime[12]; /* 136-147 */
char chksum[8]; /* 148-155 */
char typeflag; /* 156-156 */
char linkname[100]; /* 157-256 */
char magic[8]; /* 257-264 */
char uname[32]; /* 265-296 */
char gname[32]; /* 297-328 */
char devmajor[8]; /* 329-336 */
char devminor[8]; /* 337-344 */
char prefix[155]; /* 345-499 */
char padding[12]; /* 500-512 */
};
static int get_dev_null(void)
{
static int fd_null = 0;
if (fd_null == 0) {
fd_null = open("/dev/null", O_WRONLY);
if (fd_null < 0)
err(EX_OSFILE, "/dev/null");
}
return fd_null;
}
pid_t apk_open_gz(int *fd)
{
int pipe_fd[2];
pid_t child_pid;
if (pipe(pipe_fd) < 0)
err(EX_OSERR, "pipe");
child_pid = fork();
if (child_pid < 0)
err(EX_OSERR, "fork");
if (child_pid == 0) {
close(pipe_fd[0]);
dup2(pipe_fd[1], STDOUT_FILENO);
dup2(*fd, STDIN_FILENO);
dup2(get_dev_null(), STDERR_FILENO);
close(pipe_fd[1]);
execl(GUNZIP_BINARY, "gunzip", "-c", NULL);
err(EX_UNAVAILABLE, GUNZIP_BINARY);
}
close(pipe_fd[1]);
*fd = pipe_fd[0];
return child_pid;
}
#define GET_OCTAL(s) apk_blob_uint(APK_BLOB_PTR_LEN(s, sizeof(s)), 8)
static int do_splice(int from_fd, int to_fd, int len)
{
int i = 0, r;
while (i != len) {
r = splice(from_fd, NULL, to_fd, NULL, len - i, SPLICE_F_MOVE);
if (r == -1)
return i;
i += r;
}
return i;
}
int apk_parse_tar(int fd, apk_archive_entry_parser parser, void *ctx)
{
struct apk_archive_entry entry;
struct tar_header buf;
unsigned long offset = 0;
int end = 0, r;
memset(&entry, 0, sizeof(entry));
while (read(fd, &buf, 512) == 512) {
offset += 512;
if (buf.name[0] == '\0') {
if (end)
break;
end++;
continue;
}
entry = (struct apk_archive_entry){
.size = GET_OCTAL(buf.size),
.uid = GET_OCTAL(buf.uid),
.gid = GET_OCTAL(buf.gid),
.mode = GET_OCTAL(buf.mode) & 0777,
.mtime = GET_OCTAL(buf.mtime),
.name = entry.name,
.uname = buf.uname,
.gname = buf.gname,
.device = makedev(GET_OCTAL(buf.devmajor),
GET_OCTAL(buf.devminor)),
.read_fd = fd,
};
switch (buf.typeflag) {
case 'L':
if (entry.name != NULL)
free(entry.name);
entry.name = malloc(entry.size+1);
read(fd, entry.name, entry.size);
offset += entry.size;
entry.size = 0;
break;
case '0':
case '7': /* regular file */
entry.mode |= S_IFREG;
break;
case '1': /* hard link */
entry.mode |= S_IFREG;
entry.link_target = buf.linkname;
break;
case '2': /* symbolic link */
entry.mode |= S_IFLNK;
entry.link_target = buf.linkname;
break;
case '3': /* char device */
entry.mode |= S_IFCHR;
break;
case '4': /* block devicek */
entry.mode |= S_IFBLK;
break;
case '5': /* directory */
entry.mode |= S_IFDIR;
break;
default:
break;
}
if (entry.mode & S_IFMT) {
if (entry.name == NULL)
entry.name = strdup(buf.name);
/* callback parser function */
offset += entry.size;
r = parser(&entry, ctx);
if (r != 0)
return r;
offset -= entry.size;
free(entry.name);
entry.name = NULL;
}
if (entry.size)
offset += do_splice(fd, get_dev_null(), entry.size);
/* align to next 512 block */
if (offset & 511)
offset += do_splice(fd, get_dev_null(),
512 - (offset & 511));
}
return 0;
}
int apk_parse_tar_gz(int fd, apk_archive_entry_parser parser, void *ctx)
{
pid_t pid;
int r, status;
pid = apk_open_gz(&fd);
if (pid < 0)
return pid;
r = apk_parse_tar(fd, parser, ctx);
close(fd);
waitpid(pid, &status, 0);
return r;
}
apk_blob_t apk_archive_entry_read(struct apk_archive_entry *ae)
{
char *str;
int pos = 0;
ssize_t r;
str = malloc(ae->size + 1);
pos = 0;
while (ae->size) {
r = read(ae->read_fd, &str[pos], ae->size);
if (r < 0) {
free(str);
return APK_BLOB_NULL;
}
pos += r;
ae->size -= r;
}
str[pos] = 0;
return APK_BLOB_PTR_LEN(str, pos+1);
}
int apk_archive_entry_extract(struct apk_archive_entry *ae, const char *fn)
{
int r = -1;
if (fn == NULL)
fn = ae->name;
/* BIG HONKING FIXME */
unlink(fn);
switch (ae->mode & S_IFMT) {
case S_IFDIR:
r = mkdir(fn, ae->mode & 0777);
if (r < 0 && errno == EEXIST)
r = 0;
break;
case S_IFREG:
if (ae->link_target == NULL) {
r = open(fn, O_WRONLY | O_CREAT, ae->mode & 0777);
if (r < 0)
break;
ae->size -= do_splice(ae->read_fd, r, ae->size);
close(r);
r = ae->size ? -1 : 0;
} else {
r = link(ae->link_target, fn);
}
break;
case S_IFLNK:
r = symlink(ae->link_target, fn);
break;
case S_IFSOCK:
case S_IFBLK:
case S_IFCHR:
case S_IFIFO:
r = mknod(fn, ae->mode, ae->device);
break;
}
if (r != 0)
apk_error("Failed to extract %s\n", ae->name);
return r;
}
struct checksum_and_tee {
int in_fd, tee_fd;
void *ptr;
};
static void *__apk_checksum_and_tee(void *arg)
{
struct checksum_and_tee *args = (struct checksum_and_tee *) arg;
char buf[2*1024];
int r, w, wt;
__off64_t offset;
csum_ctx_t ctx;
int dosplice = 1;
offset = lseek(args->in_fd, 0, SEEK_CUR);
csum_init(&ctx);
do {
r = read(args->in_fd, buf, sizeof(buf));
if (r <= 0)
break;
wt = 0;
do {
if (dosplice) {
w = splice(args->in_fd, &offset, args->tee_fd, NULL,
r - wt, SPLICE_F_MOVE);
if (w < 0) {
dosplice = 0;
continue;
}
} else {
w = write(args->tee_fd, &buf[wt], r - wt);
if (w < 0)
break;
}
wt += w;
} while (wt != r);
csum_process(&ctx, buf, r);
} while (r == sizeof(buf));
csum_finish(&ctx, args->ptr);
close(args->tee_fd);
close(args->in_fd);
free(args);
return NULL;
}
pthread_t apk_checksum_and_tee(int *fd, void *ptr)
{
struct checksum_and_tee *args;
int fds[2];
pthread_t tid;
if (pipe(fds) < 0)
return -1;
fcntl(fds[0], F_SETFD, FD_CLOEXEC);
fcntl(fds[1], F_SETFD, FD_CLOEXEC);
args = malloc(sizeof(*args));
*args = (struct checksum_and_tee){ *fd, fds[1], ptr };
if (pthread_create(&tid, NULL, __apk_checksum_and_tee, args) < 0)
return -1;
*fd = fds[0];
return tid;
}
