/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/blocksigs.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/cmpxchg.h"
#include "libc/intrin/directmap.internal.h"
#include "libc/intrin/extend.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/nexgen32e/crc32.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/memtrack.internal.h"
#include "libc/sysv/consts/f.h"
#include "libc/sysv/consts/fd.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/thread.h"
#include "libc/zip.h"
#include "libc/zipos/zipos.internal.h"
static char *mapend;
static size_t maptotal;
static void *__zipos_mmap_space(size_t mapsize) {
char *start;
size_t offset;
_unassert(mapsize);
offset = maptotal;
maptotal += mapsize;
start = (char *)kMemtrackZiposStart;
if (!mapend) mapend = start;
mapend = _extend(start, maptotal, mapend, MAP_PRIVATE,
kMemtrackZiposStart + kMemtrackZiposSize);
return start + offset;
}
static struct ZiposHandle *__zipos_alloc(struct Zipos *zipos, size_t size) {
size_t mapsize;
struct ZiposHandle *h, **ph;
__zipos_lock();
mapsize = sizeof(struct ZiposHandle) + size;
mapsize = ROUNDUP(mapsize, 4096);
StartOver:
ph = &zipos->freelist;
while ((h = *ph)) {
if (h->mapsize >= mapsize) {
if (!_cmpxchg(ph, h, h->next)) goto StartOver;
h->next = 0;
break;
}
ph = &h->next;
}
if (!h) {
h = __zipos_mmap_space(mapsize);
}
__zipos_unlock();
if (IsAsan()) {
__asan_unpoison((char *)h, sizeof(struct ZiposHandle) + size);
__asan_poison((char *)h + sizeof(struct ZiposHandle) + size,
mapsize - (sizeof(struct ZiposHandle) + size),
kAsanHeapOverrun);
}
if (h) {
h->size = size;
h->mapsize = mapsize;
pthread_mutex_init(&h->lock, 0);
}
return h;
}
static int __zipos_mkfd(int minfd) {
int e, fd;
static bool demodernize;
if (!demodernize) {
e = errno;
if ((fd = __sys_fcntl(2, F_DUPFD_CLOEXEC, minfd)) != -1) {
return fd;
} else if (errno == EINVAL) {
demodernize = true;
errno = e;
} else {
return fd;
}
}
if ((fd = __sys_fcntl(2, F_DUPFD, minfd)) != -1) {
__sys_fcntl(fd, F_SETFD, FD_CLOEXEC);
}
return fd;
}
static int __zipos_setfd(int fd, struct ZiposHandle *h, unsigned flags,
int mode) {
int want = fd;
atomic_compare_exchange_strong_explicit(
&g_fds.f, &want, fd + 1, memory_order_release, memory_order_relaxed);
g_fds.p[fd].kind = kFdZip;
g_fds.p[fd].handle = (intptr_t)h;
g_fds.p[fd].flags = flags | O_CLOEXEC;
g_fds.p[fd].mode = mode;
g_fds.p[fd].extra = 0;
__fds_unlock();
return fd;
}
static int __zipos_load(struct Zipos *zipos, size_t cf, unsigned flags,
int mode) {
size_t lf;
size_t size;
int rc, fd, minfd;
struct ZiposHandle *h;
lf = GetZipCfileOffset(zipos->map + cf);
_npassert((ZIP_LFILE_MAGIC(zipos->map + lf) == kZipLfileHdrMagic));
size = GetZipLfileUncompressedSize(zipos->map + lf);
switch (ZIP_LFILE_COMPRESSIONMETHOD(zipos->map + lf)) {
case kZipCompressionNone:
if (!(h = __zipos_alloc(zipos, 0))) return -1;
h->mem = ZIP_LFILE_CONTENT(zipos->map + lf);
break;
case kZipCompressionDeflate:
if (!(h = __zipos_alloc(zipos, size))) return -1;
if (!__inflate(h->data, size, ZIP_LFILE_CONTENT(zipos->map + lf),
GetZipLfileCompressedSize(zipos->map + lf))) {
h->mem = h->data;
} else {
h->mem = 0;
eio();
}
break;
default:
return eio();
}
h->pos = 0;
h->cfile = cf;
h->size = size;
if (!IsTiny() && h->mem &&
crc32_z(0, h->mem, h->size) != ZIP_LFILE_CRC32(zipos->map + lf)) {
h->mem = 0;
eio();
}
if (h->mem) {
minfd = 3;
__fds_lock();
TryAgain:
if (IsWindows() || IsMetal()) {
if ((fd = __reservefd_unlocked(-1)) != -1) {
return __zipos_setfd(fd, h, flags, mode);
}
} else if ((fd = __zipos_mkfd(minfd)) != -1) {
if (__ensurefds_unlocked(fd) != -1) {
if (g_fds.p[fd].kind) {
sys_close(fd);
minfd = fd + 1;
goto TryAgain;
}
return __zipos_setfd(fd, h, flags, mode);
}
sys_close(fd);
}
__fds_unlock();
}
__zipos_free(zipos, h);
return -1;
}
/**
* Loads compressed file from αcτµαlly pδrταblε εxεcµταblε object store.
*
* @param uri is obtained via __zipos_parseuri()
* @asyncsignalsafe
* @threadsafe
*/
int __zipos_open(const struct ZiposUri *name, unsigned flags, int mode) {
int rc;
ssize_t cf;
struct Zipos *zipos;
if (_weaken(pthread_testcancel_np) &&
(rc = _weaken(pthread_testcancel_np)())) {
errno = rc;
return -1;
}
BLOCK_SIGNALS;
if ((flags & O_ACCMODE) == O_RDONLY) {
if ((zipos = __zipos_get())) {
if ((cf = __zipos_find(zipos, name)) != -1) {
rc = __zipos_load(zipos, cf, flags, mode);
} else {
rc = enoent();
}
} else {
rc = enoexec();
}
} else {
rc = einval();
}
ALLOW_SIGNALS;
return rc;
}