2 files changed, 709 insertions, 0 deletions
diff --git a/libexec/flua/modules/lposix.c b/libexec/flua/modules/lposix.c
new file mode 100644
index 000000000000..75cdd345aeaa
--- /dev/null
+++ b/libexec/flua/modules/lposix.c
@@ -0,0 +1,699 @@
+/*-
+ * Copyright (c) 2019, 2023 Kyle Evans <kevans@FreeBSD.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <sys/stat.h>
+#include <sys/utsname.h>
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <fnmatch.h>
+#include <grp.h>
+#include <libgen.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <lua.h>
+#include "lauxlib.h"
+#include "lposix.h"
+
+static void
+enforce_max_args(lua_State *L, int max)
+{
+	int narg;
+
+	narg = lua_gettop(L);
+	luaL_argcheck(L, narg <= max, max + 1, "too many arguments");
+}
+
+/*
+ * Minimal implementation of luaposix needed for internal FreeBSD bits.
+ */
+static int
+lua__exit(lua_State *L)
+{
+	int code;
+
+	enforce_max_args(L, 1);
+	code = luaL_checkinteger(L, 1);
+
+	_exit(code);
+}
+
+static int
+lua_basename(lua_State *L)
+{
+	char *inpath, *outpath;
+
+	enforce_max_args(L, 1);
+	inpath = strdup(luaL_checkstring(L, 1));
+	if (inpath == NULL) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(ENOMEM));
+		lua_pushinteger(L, ENOMEM);
+		return (3);
+	}
+
+	outpath = basename(inpath);
+	lua_pushstring(L, outpath);
+	free(inpath);
+	return (1);
+}
+
+static int
+lua_chmod(lua_State *L)
+{
+	const char *path;
+	mode_t mode;
+
+	enforce_max_args(L, 2);
+	path = luaL_checkstring(L, 1);
+	mode = (mode_t)luaL_checkinteger(L, 2);
+
+	if (chmod(path, mode) == -1) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+	lua_pushinteger(L, 0);
+	return (1);
+}
+
+static int
+lua_chown(lua_State *L)
+{
+	const char *path;
+	uid_t owner = (uid_t)-1;
+	gid_t group = (gid_t)-1;
+	int error;
+
+	enforce_max_args(L, 3);
+
+	path = luaL_checkstring(L, 1);
+	if (lua_isinteger(L, 2))
+		owner = (uid_t)lua_tointeger(L, 2);
+	else if (lua_isstring(L, 2)) {
+		char buf[4096];
+		struct passwd passwd, *pwd;
+
+		error = getpwnam_r(lua_tostring(L, 2), &passwd,
+		    buf, sizeof(buf), &pwd);
+		if (error == 0)
+			owner = pwd->pw_uid;
+		else
+			return (luaL_argerror(L, 2,
+			    lua_pushfstring(L, "unknown user %s",
+			    lua_tostring(L, 2))));
+	} else if (!lua_isnoneornil(L, 2)) {
+		const char *type = luaL_typename(L, 2);
+		return (luaL_argerror(L, 2,
+		    lua_pushfstring(L, "integer or string expected, got %s",
+		    type)));
+	}
+
+	if (lua_isinteger(L, 3))
+		group = (gid_t)lua_tointeger(L, 3);
+	else if (lua_isstring(L, 3)) {
+		char buf[4096];
+		struct group gr, *grp;
+
+		error = getgrnam_r(lua_tostring(L, 3), &gr, buf, sizeof(buf),
+		    &grp);
+		if (error == 0)
+			group = grp->gr_gid;
+		else
+			return (luaL_argerror(L, 3,
+			    lua_pushfstring(L, "unknown group %s",
+			    lua_tostring(L, 3))));
+	} else if (!lua_isnoneornil(L, 3)) {
+		const char *type = luaL_typename(L, 3);
+		return (luaL_argerror(L, 3,
+		    lua_pushfstring(L, "integer or string expected, got %s",
+		    type)));
+	}
+
+	if (chown(path, owner, group) == -1) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+	lua_pushinteger(L, 0);
+	return (1);
+}
+
+static int
+lua_pclose(lua_State *L)
+{
+	int error, fd;
+
+	enforce_max_args(L, 1);
+
+	fd = luaL_checkinteger(L, 1);
+	if (fd < 0) {
+		error = EBADF;
+		goto err;
+	}
+
+	if (close(fd) == 0) {
+		lua_pushinteger(L, 0);
+		return (1);
+	}
+
+	error = errno;
+err:
+	lua_pushnil(L);
+	lua_pushstring(L, strerror(error));
+	lua_pushinteger(L, error);
+	return (3);
+
+}
+
+static int
+lua_dup2(lua_State *L)
+{
+	int error, oldd, newd;
+
+	enforce_max_args(L, 2);
+
+	oldd = luaL_checkinteger(L, 1);
+	if (oldd < 0) {
+		error = EBADF;
+		goto err;
+	}
+
+	newd = luaL_checkinteger(L, 2);
+	if (newd < 0) {
+		error = EBADF;
+		goto err;
+	}
+
+	error = dup2(oldd, newd);
+	if (error >= 0) {
+		lua_pushinteger(L, error);
+		return (1);
+	}
+
+	error = errno;
+err:
+	lua_pushnil(L);
+	lua_pushstring(L, strerror(error));
+	lua_pushinteger(L, error);
+	return (3);
+}
+
+static int
+lua_execp(lua_State *L)
+{
+	int argc, error;
+	const char *file;
+	const char **argv;
+
+	enforce_max_args(L, 2);
+
+	file = luaL_checkstring(L, 1);
+	luaL_checktype(L, 2, LUA_TTABLE);
+
+	lua_len(L, 2);
+	argc = lua_tointeger(L, -1);
+
+	/*
+	 * Use lua_newuserdatauv() to allocate a scratch buffer that is tracked
+	 * and freed by lua's GC. This avoid any chance of a leak if a lua error
+	 * is raised later in this function (e.g. by luaL_argerror()).
+	 * The (argc + 2) size gives enough space in the buffer for argv[0] and
+	 * the terminating NULL.
+	 */
+	argv = lua_newuserdatauv(L, (argc + 2) * sizeof(char *), 0);
+
+	/*
+	 * Sequential tables in lua start at index 1 by convention.
+	 * If there happens to be a string at index 0, use that to
+	 * override the default argv[0]. This matches the lposix API.
+	 */
+	lua_pushinteger(L, 0);
+	lua_gettable(L, 2);
+	argv[0] = lua_tostring(L, -1);
+	if (argv[0] == NULL) {
+		argv[0] = file;
+	}
+
+	for (int i = 1; i <= argc; i++) {
+		lua_pushinteger(L, i);
+		lua_gettable(L, 2);
+		argv[i] = lua_tostring(L, -1);
+		if (argv[i] == NULL) {
+			luaL_argerror(L, 2,
+			    "argv table must contain only strings");
+		}
+	}
+	argv[argc + 1] = NULL;
+
+	execvp(file, (char **)argv);
+	error = errno;
+
+	lua_pushnil(L);
+	lua_pushstring(L, strerror(error));
+	lua_pushinteger(L, error);
+	return (3);
+}
+
+static int
+lua_fnmatch(lua_State *L)
+{
+	const char *pattern, *string;
+	int flags;
+
+	enforce_max_args(L, 3);
+	pattern = luaL_checkstring(L, 1);
+	string = luaL_checkstring(L, 2);
+	flags = luaL_optinteger(L, 3, 0);
+
+	lua_pushinteger(L, fnmatch(pattern, string, flags));
+
+	return (1);
+}
+
+static int
+lua_uname(lua_State *L)
+{
+	struct utsname name;
+	int error;
+
+	enforce_max_args(L, 0);
+
+	error = uname(&name);
+	if (error != 0) {
+		error = errno;
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(error));
+		lua_pushinteger(L, error);
+		return (3);
+	}
+
+	lua_newtable(L);
+#define	setkv(f) do {			\
+	lua_pushstring(L, name.f);	\
+	lua_setfield(L, -2, #f);	\
+} while (0)
+	setkv(sysname);
+	setkv(nodename);
+	setkv(release);
+	setkv(version);
+	setkv(machine);
+#undef setkv
+
+	return (1);
+}
+
+static int
+lua_dirname(lua_State *L)
+{
+	char *inpath, *outpath;
+
+	enforce_max_args(L, 1);
+
+	inpath = strdup(luaL_checkstring(L, 1));
+	if (inpath == NULL) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(ENOMEM));
+		lua_pushinteger(L, ENOMEM);
+		return (3);
+	}
+
+	outpath = dirname(inpath);
+	lua_pushstring(L, outpath);
+	free(inpath);
+	return (1);
+}
+
+static int
+lua_fork(lua_State *L)
+{
+	pid_t pid;
+
+	enforce_max_args(L, 0);
+
+	pid = fork();
+	if (pid < 0) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+
+	lua_pushinteger(L, pid);
+	return (1);
+}
+
+static int
+lua_getpid(lua_State *L)
+{
+	enforce_max_args(L, 0);
+
+	lua_pushinteger(L, getpid());
+	return (1);
+}
+
+static int
+lua_pipe(lua_State *L)
+{
+	int error, fd[2];
+
+	enforce_max_args(L, 0);
+
+	error = pipe(fd);
+	if (error != 0) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (1);
+	}
+
+	lua_pushinteger(L, fd[0]);
+	lua_pushinteger(L, fd[1]);
+	return (2);
+}
+
+static int
+lua_read(lua_State *L)
+{
+	char *buf;
+	ssize_t ret;
+	size_t sz;
+	int error, fd;
+
+	enforce_max_args(L, 2);
+	fd = luaL_checkinteger(L, 1);
+	sz = luaL_checkinteger(L, 2);
+
+	if (fd < 0) {
+		error = EBADF;
+		goto err;
+	}
+
+	buf = malloc(sz);
+	if (buf == NULL)
+		goto err;
+
+	/*
+	 * For 0-byte reads, we'll still push the empty string and let the
+	 * caller deal with EOF to match lposix semantics.
+	 */
+	ret = read(fd, buf, sz);
+	if (ret >= 0)
+		lua_pushlstring(L, buf, ret);
+	else if (ret < 0)
+		error = errno; /* Save to avoid clobber by free() */
+
+	free(buf);
+	if (error != 0)
+		goto err;
+
+	/* Just the string pushed. */
+	return (1);
+err:
+	lua_pushnil(L);
+	lua_pushstring(L, strerror(error));
+	lua_pushinteger(L, error);
+	return (3);
+}
+
+static int
+lua_realpath(lua_State *L)
+{
+	const char *inpath;
+	char *outpath;
+
+	enforce_max_args(L, 1);
+	inpath = luaL_checkstring(L, 1);
+
+	outpath = realpath(inpath, NULL);
+	if (outpath == NULL) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+
+	lua_pushstring(L, outpath);
+	free(outpath);
+	return (1);
+}
+
+static int
+lua_wait(lua_State *L)
+{
+	pid_t pid;
+	int options, status;
+
+	enforce_max_args(L, 2);
+	pid = luaL_optinteger(L, 1, -1);
+	options = luaL_optinteger(L, 2, 0);
+
+	status = 0;
+	pid = waitpid(pid, &status, options);
+	if (pid < 0) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+
+	lua_pushinteger(L, pid);
+	if (pid == 0) {
+		lua_pushliteral(L, "running");
+		return (2);
+	}
+
+	if (WIFCONTINUED(status)) {
+		lua_pushliteral(L, "continued");
+		return (2);
+	} else if(WIFSTOPPED(status)) {
+		lua_pushliteral(L, "stopped");
+		lua_pushinteger(L, WSTOPSIG(status));
+		return (3);
+	} else if (WIFEXITED(status)) {
+		lua_pushliteral(L, "exited");
+		lua_pushinteger(L, WEXITSTATUS(status));
+		return (3);
+	} else if (WIFSIGNALED(status)) {
+		lua_pushliteral(L, "killed");
+		lua_pushinteger(L, WTERMSIG(status));
+		return (3);
+	}
+
+	return (1);
+}
+
+static int
+lua_write(lua_State *L)
+{
+	const char *buf;
+	size_t bufsz, sz;
+	ssize_t ret;
+	off_t offset;
+	int error, fd;
+
+	enforce_max_args(L, 4);
+
+	fd = luaL_checkinteger(L, 1);
+	if (fd < 0) {
+		error = EBADF;
+		goto err;
+	}
+
+	buf = luaL_checkstring(L, 2);
+
+	bufsz = lua_rawlen(L, 2);
+	sz = luaL_optinteger(L, 3, bufsz);
+
+	offset = luaL_optinteger(L, 4, 0);
+
+
+	if ((size_t)offset > bufsz || offset + sz > bufsz) {
+		lua_pushnil(L);
+		lua_pushfstring(L,
+		    "write: invalid access offset %zu, size %zu in a buffer size %zu",
+		    offset, sz, bufsz);
+		lua_pushinteger(L, EINVAL);
+		return (3);
+	}
+
+	ret = write(fd, buf + offset, sz);
+	if (ret < 0) {
+		error = errno;
+		goto err;
+	}
+
+	lua_pushinteger(L, ret);
+	return (1);
+err:
+	lua_pushnil(L);
+	lua_pushstring(L, strerror(error));
+	lua_pushinteger(L, error);
+	return (3);
+}
+
+#define	REG_DEF(n, func)	{ #n, func }
+#define REG_SIMPLE(n)		REG_DEF(n, lua_ ## n)
+static const struct luaL_Reg libgenlib[] = {
+	REG_SIMPLE(basename),
+	REG_SIMPLE(dirname),
+	{ NULL, NULL },
+};
+
+static const struct luaL_Reg stdliblib[] = {
+	REG_SIMPLE(realpath),
+	{ NULL, NULL },
+};
+
+static const struct luaL_Reg fnmatchlib[] = {
+	REG_SIMPLE(fnmatch),
+	{ NULL, NULL },
+};
+
+static const struct luaL_Reg sys_statlib[] = {
+	REG_SIMPLE(chmod),
+	{ NULL, NULL },
+};
+
+static const struct luaL_Reg sys_utsnamelib[] = {
+	REG_SIMPLE(uname),
+	{ NULL, NULL },
+};
+
+static const struct luaL_Reg sys_waitlib[] = {
+	REG_SIMPLE(wait),
+	{NULL, NULL},
+};
+
+static const struct luaL_Reg unistdlib[] = {
+	REG_SIMPLE(_exit),
+	REG_SIMPLE(chown),
+	REG_DEF(close, lua_pclose),
+	REG_SIMPLE(dup2),
+	REG_SIMPLE(execp),
+	REG_SIMPLE(fork),
+	REG_SIMPLE(getpid),
+	REG_SIMPLE(pipe),
+	REG_SIMPLE(read),
+	REG_SIMPLE(write),
+	{ NULL, NULL },
+};
+
+#undef REG_SIMPLE
+#undef REG_DEF
+
+static int
+luaopen_posix_libgen(lua_State *L)
+{
+	luaL_newlib(L, libgenlib);
+	return (1);
+}
+
+static int
+luaopen_posix_stdlib(lua_State *L)
+{
+	luaL_newlib(L, stdliblib);
+	return (1);
+}
+
+static int
+luaopen_posix_fnmatch(lua_State *L)
+{
+	luaL_newlib(L, fnmatchlib);
+
+#define	setkv(f) do {			\
+	lua_pushinteger(L, f);		\
+	lua_setfield(L, -2, #f);	\
+} while (0)
+	setkv(FNM_PATHNAME);
+	setkv(FNM_NOESCAPE);
+	setkv(FNM_NOMATCH);
+	setkv(FNM_PERIOD);
+#undef setkv
+
+	return 1;
+}
+
+static int
+luaopen_posix_sys_stat(lua_State *L)
+{
+	luaL_newlib(L, sys_statlib);
+	return (1);
+}
+
+static int
+luaopen_posix_sys_utsname(lua_State *L)
+{
+	luaL_newlib(L, sys_utsnamelib);
+	return 1;
+}
+
+static int
+luaopen_posix_sys_wait(lua_State *L)
+{
+	luaL_newlib(L, sys_waitlib);
+
+#define	lua_pushflag(L, flag) do {	\
+	lua_pushinteger(L, flag);	\
+	lua_setfield(L, -2, #flag);	\
+} while(0)
+
+	/* Only these two exported by lposix */
+	lua_pushflag(L, WNOHANG);
+	lua_pushflag(L, WUNTRACED);
+
+	lua_pushflag(L, WCONTINUED);
+	lua_pushflag(L, WSTOPPED);
+#ifdef WTRAPPED
+	lua_pushflag(L, WTRAPPED);
+#endif
+	lua_pushflag(L, WEXITED);
+	lua_pushflag(L, WNOWAIT);
+#undef lua_pushflag
+
+	return (1);
+}
+
+static int
+luaopen_posix_unistd(lua_State *L)
+{
+	luaL_newlib(L, unistdlib);
+	return (1);
+}
+
+int
+luaopen_posix(lua_State *L)
+{
+	lua_newtable(L); /* posix */
+
+	luaL_requiref(L, "posix.fnmatch", luaopen_posix_fnmatch, 0);
+	lua_setfield(L, -2, "fnmatch");
+
+	luaL_requiref(L, "posix.libgen", luaopen_posix_libgen, 0);
+	lua_setfield(L, -2, "libgen");
+
+	luaL_requiref(L, "posix.stdlib", luaopen_posix_stdlib, 0);
+	lua_setfield(L, -2, "stdlib");
+
+	lua_newtable(L); /* posix.sys */
+	luaL_requiref(L, "posix.sys.stat", luaopen_posix_sys_stat, 0);
+	lua_setfield(L, -2, "stat");
+	luaL_requiref(L, "posix.sys.utsname", luaopen_posix_sys_utsname, 0);
+	lua_setfield(L, -2, "utsname");
+	luaL_requiref(L, "posix.sys.wait", luaopen_posix_sys_wait, 0);
+	lua_setfield(L, -2, "wait");
+	lua_setfield(L, -2, "sys");
+
+	luaL_requiref(L, "posix.unistd", luaopen_posix_unistd, 0);
+	lua_setfield(L, -2, "unistd");
+
+	return (1);
+}
diff --git a/libexec/flua/modules/lposix.h b/libexec/flua/modules/lposix.h
new file mode 100644
index 000000000000..1aa33f042571
--- /dev/null
+++ b/libexec/flua/modules/lposix.h
@@ -0,0 +1,10 @@
+/*-
+ *
+ * This file is in the public domain.
+ */
+
+#pragma once
+
+#include <lua.h>
+
+int luaopen_posix(lua_State *L);