cosmopolitan/libc/calls/execve-sysv.c
Justine Tunney f7ff77d865
Make fixes and improvements
- Invent iso8601us() for faster timestamps
- Improve --strace descriptions of sigset_t
- Rebuild the Landlock Make bootstrap binary
- Introduce MODE=sysv for non-Windows builds
- Permit OFD fcntl() locks under pledge(flock)
- redbean can now protect your kernel from ddos
- Have vfork() fallback to sys_fork() not fork()
- Change kmalloc() to not die when out of memory
- Improve documentation for some termios functions
- Rewrite putenv() and friends to conform to POSIX
- Fix linenoise + strace verbosity issue on Windows
- Fix regressions in our ability to show backtraces
- Change redbean SetHeader() to no-op if value is nil
- Improve fcntl() so SQLite locks work in non-WAL mode
- Remove some unnecessary work during fork() on Windows
- Create redbean-based SSL reverse proxy for IPv4 TurfWar
- Fix ape/apeinstall.sh warning when using non-bash shells
- Add ProgramTrustedIp(), and IsTrustedIp() APIs to redbean
- Support $PWD, $UID, $GID, and $EUID in command interpreter
- Introduce experimental JTqFpD APE prefix for non-Windows builds
- Invent blackhole daemon for firewalling IP addresses via UNIX named socket
- Add ProgramTokenBucket(), AcquireToken(), and CountTokens() APIs to redbean
2022-10-19 07:19:19 -07:00

104 lines
4.1 KiB
C

/*-*- 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 2021 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/calls/blocksigs.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/bits.h"
#include "libc/intrin/safemacros.internal.h"
#include "libc/mem/alloca.h"
#include "libc/paths.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/at.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/ok.h"
#include "libc/sysv/errfuns.h"
static bool CanExecute(const char *path) {
return !sys_faccessat(AT_FDCWD, path, X_OK, 0);
}
static bool IsApeBinary(const char *path) {
int fd;
char buf[8];
bool res = false;
if ((fd = sys_open(path, O_RDONLY, 0)) != -1) {
if (sys_read(fd, buf, 8) == 8 && //
(READ64LE(buf) == READ64LE("MZqFpD='") ||
READ64LE(buf) == READ64LE("JTqFpD='"))) {
res = true;
}
sys_close(fd);
}
return res;
}
static const char *Join(const char *a, const char *b, char buf[PATH_MAX]) {
size_t n, m;
n = strlen(a);
m = strlen(b);
if (n + 1 + m + 1 < PATH_MAX) {
stpcpy(stpcpy(stpcpy(buf, a), "/"), b);
return buf;
} else {
return "";
}
}
int sys_execve(const char *prog, char *const argv[], char *const envp[]) {
size_t i;
int e, rc;
char *buf;
char **shargs;
const char *ape;
e = errno;
__sys_execve(prog, argv, envp);
if (errno == ENOEXEC) {
for (i = 0; argv[i];) ++i;
buf = alloca(PATH_MAX);
shargs = alloca((i + 4) * sizeof(char *));
if (IsApeBinary(prog) &&
(CanExecute((ape = "/usr/bin/ape")) ||
CanExecute((ape = Join(firstnonnull(getenv("TMPDIR"),
firstnonnull(getenv("HOME"), ".")),
".ape", buf))) ||
CanExecute(
(ape = Join(firstnonnull(getenv("HOME"), "."), ".ape", buf))))) {
shargs[0] = ape;
shargs[1] = "-";
shargs[2] = prog;
memcpy(shargs + 3, argv, (i + 1) * sizeof(char *));
errno = e;
rc = __sys_execve(shargs[0], shargs, envp);
} else if (CanExecute(prog)) {
shargs[0] = _PATH_BSHELL;
shargs[1] = prog;
memcpy(shargs + 2, argv + 1, i * sizeof(char *));
errno = e;
rc = __sys_execve(shargs[0], shargs, envp);
} else {
rc = enoexec();
}
} else {
rc = -1;
}
return rc;
}