feat(process): allow commands and envs on proces_start (#1477)

* feat(process): allow commands and envs on proces_start

* refactor(process): copy process arguments once whenever possible

Refactors the code to use an arglist type which is just lpCmdline on Windows
and a list in Linux.
The function automatically escapes the command when it is needed, avoiding
a second copy.

This also allows UTF-8 commands btw.

* fix(process): fix invalid dereference

* refactor(process): mark xstrdup as potentially unused

* feat(process): add parent process environment when launching process

* fix(process): fix operator precedence with array operators

* fix(process): fix segfault when freeing random memory

* fix(process): fix wrong check for setenv()

* fix(process): fix accidentally initializing an array by assignment

* fix(process): clear return value if success
This commit is contained in:
Takase 2023-11-30 23:33:24 +08:00 committed by takase1121
parent 8e2928aeb8
commit 311651333a
No known key found for this signature in database
GPG Key ID: 60EEFFC68EB3031B
1 changed files with 328 additions and 94 deletions

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@ -31,6 +31,8 @@
typedef DWORD process_error_t;
typedef HANDLE process_stream_t;
typedef HANDLE process_handle_t;
typedef wchar_t process_arglist_t[32767];
typedef wchar_t *process_env_t;
#define HANDLE_INVALID (INVALID_HANDLE_VALUE)
#define PROCESS_GET_HANDLE(P) ((P)->process_information.hProcess)
@ -42,12 +44,20 @@ static volatile long PipeSerialNumber;
typedef int process_error_t;
typedef int process_stream_t;
typedef pid_t process_handle_t;
typedef char **process_arglist_t;
typedef char **process_env_t;
#define HANDLE_INVALID (0)
#define PROCESS_GET_HANDLE(P) ((P)->pid)
#endif
#ifdef __GNUC__
#define UNUSED __attribute__((__unused__))
#else
#define UNUSED
#endif
typedef struct {
bool running, detached;
int returncode, deadline;
@ -339,14 +349,248 @@ static bool signal_process(process_t* proc, signal_e sig) {
return true;
}
static UNUSED char *xstrdup(const char *str) {
char *result = str ? malloc(strlen(str) + 1) : NULL;
if (result) strcpy(result, str);
return result;
}
static int process_arglist_init(process_arglist_t *list, size_t *list_len, size_t nargs) {
*list_len = 0;
#ifdef _WIN32
memset(*list, 0, sizeof(process_arglist_t));
#else
*list = calloc(sizeof(char *), nargs + 1);
if (!*list) return ENOMEM;
#endif
return 0;
}
static int process_arglist_add(process_arglist_t *list, size_t *list_len, const char *arg, bool escape) {
size_t len = *list_len;
#ifdef _WIN32
int arg_len;
wchar_t *cmdline = *list;
wchar_t arg_w[32767];
// this length includes the null terminator!
if (!(arg_len = MultiByteToWideChar(CP_UTF8, 0, arg, -1, arg_w, 32767)))
return GetLastError();
if (arg_len + len > 32767)
return ERROR_NOT_ENOUGH_MEMORY;
if (!escape) {
// replace the current null terminator with a space
if (len > 0) cmdline[len-1] = ' ';
memcpy(cmdline + len, arg_w, arg_len * sizeof(wchar_t));
len += arg_len;
} else {
// if the string contains spaces, then we must quote it
bool quote = wcspbrk(arg_w, L" \t\v\r\n");
int backslash = 0, escaped_len = quote ? 2 : 0;
for (int i = 0; i < arg_len; i++) {
if (arg_w[i] == L'\\') {
backslash++;
} else if (arg_w[i] == L'"') {
escaped_len += backslash + 1;
backslash = 0;
} else {
backslash = 0;
}
escaped_len++;
}
// escape_len contains NUL terminator
if (escaped_len + len > 32767)
return ERROR_NOT_ENOUGH_MEMORY;
// replace our previous NUL terminator with space
if (len > 0) cmdline[len-1] = L' ';
if (quote) cmdline[len++] = L'"';
// we are not going to iterate over NUL terminator
for (int i = 0;arg_w[i]; i++) {
if (arg_w[i] == L'\\') {
backslash++;
} else if (arg_w[i] == L'"') {
// add backslash + 1 backslashes
for (int j = 0; j < backslash; j++)
cmdline[len++] = L'\\';
cmdline[len++] = L'\\';
backslash = 0;
} else {
backslash = 0;
}
cmdline[len++] = arg_w[i];
}
if (quote) cmdline[len++] = L'"';
cmdline[len++] = L'\0';
}
#else
char **cmd = *list;
cmd[len] = xstrdup(arg);
if (!cmd[len]) return ENOMEM;
len++;
#endif
*list_len = len;
return 0;
}
static void process_arglist_free(process_arglist_t *list) {
#ifndef _WIN32
char **cmd = *list;
for (int i = 0; cmd[i]; i++)
free(cmd[i]);
free(cmd);
*list = NULL;
#endif
}
static int process_env_init(process_env_t *env_list, size_t *env_len, size_t nenv) {
*env_len = 0;
#ifdef _WIN32
*env_list = NULL;
#else
*env_list = calloc(sizeof(char *), nenv * 2);
if (!*env_list) return ENOMEM;
#endif
return 0;
}
#ifdef _WIN32
static int cmp_name(wchar_t *a, wchar_t *b) {
wchar_t _A[32767], _B[32767], *A = _A, *B = _B, *a_eq, *b_eq;
int na, nb, r;
a_eq = wcschr(a, L'=');
b_eq = wcschr(b, L'=');
assert(a_eq);
assert(b_eq);
na = a_eq - a;
nb = b_eq - b;
r = LCMapStringW(LOCALE_INVARIANT, LCMAP_UPPERCASE, a, na, A, na);
assert(r == na);
A[na] = L'\0';
r = LCMapStringW(LOCALE_INVARIANT, LCMAP_UPPERCASE, b, nb, B, nb);
assert(r == nb);
B[nb] = L'\0';
for (;;) {
wchar_t AA = *A++, BB = *B++;
if (AA > BB)
return 1;
else if (AA < BB)
return -1;
else if (!AA && !BB)
return 0;
}
}
static int process_env_add_variable(process_env_t *env_list, size_t *env_list_len, wchar_t *var, size_t var_len) {
wchar_t *list, *list_p;
size_t block_var_len, list_len;
list = list_p = *env_list;
list_len = *env_list_len;
if (list_len) {
// check if it is already in the block
while ((block_var_len = wcslen(list_p))) {
if (cmp_name(list_p, var) == 0)
return -1; // already installed
list_p += block_var_len + 1;
}
}
// allocate list + 1 characters for the block terminator
list = realloc(list, (list_len + var_len + 1) * sizeof(wchar_t));
if (!list) return ERROR_NOT_ENOUGH_MEMORY;
// copy the env variable to the block
memcpy(list + list_len, var, var_len * sizeof(wchar_t));
// terminate the block again
list[list_len + var_len] = L'\0';
*env_list = list;
*env_list_len = (list_len + var_len);
return 0;
}
static int process_env_add_system(process_env_t *env_list, size_t *env_list_len) {
int retval = 0;
wchar_t *proc_env_block, *proc_env_block_p;
int proc_env_len;
proc_env_block = proc_env_block_p = GetEnvironmentStringsW();
while ((proc_env_len = wcslen(proc_env_block_p))) {
// try to add it to the list
if ((retval = process_env_add_variable(env_list, env_list_len, proc_env_block_p, proc_env_len + 1)) > 0)
goto cleanup;
proc_env_block_p += proc_env_len + 1;
}
retval = 0;
cleanup:
if (proc_env_block) FreeEnvironmentStringsW(proc_env_block);
return retval;
}
#endif
static int process_env_add(process_env_t *env_list, size_t *env_len, const char *key, const char *value) {
#ifdef _WIN32
wchar_t env_var[32767];
int r, var_len = 0;
if (!(r = MultiByteToWideChar(CP_UTF8, 0, key, -1, env_var, 32767)))
return GetLastError();
var_len += r;
env_var[var_len-1] = L'=';
if (!(r = MultiByteToWideChar(CP_UTF8, 0, value, -1, env_var + var_len, 32767 - var_len)))
return GetLastError();
var_len += r;
return process_env_add_variable(env_list, env_len, env_var, var_len);
#else
(*env_list)[*env_len] = xstrdup(key);
if (!(*env_list)[*env_len])
return ENOMEM;
(*env_list)[*env_len + 1] = xstrdup(value);
if (!(*env_list)[*env_len + 1])
return ENOMEM;
*env_len += 2;
#endif
return 0;
}
static void process_env_free(process_env_t *list) {
if (!*list) return;
#ifdef _WIN32
free(*list);
#else
for (size_t i = 0; (*list)[i]; i++) free((*list)[i]);
free(*list);
#endif
*list = NULL;
}
static int process_start(lua_State* L) {
int retval = 1;
size_t env_len = 0, key_len, val_len;
const char *cmd[256] = { NULL }, *env_names[256] = { NULL }, *env_values[256] = { NULL }, *cwd = NULL;
bool detach = false, literal = false;
int r, retval = 1;
size_t env_len = 0, cmd_len = 0, arglist_len = 0, env_vars_len = 0;
process_arglist_t arglist;
process_env_t env_vars = NULL;
const char *cwd = NULL;
bool detach = false, escape = true;
int deadline = 10, new_fds[3] = { STDIN_FD, STDOUT_FD, STDERR_FD };
size_t arg_len = lua_gettop(L), cmd_len;
if (lua_type(L, 1) == LUA_TTABLE) {
if (lua_isstring(L, 1)) {
escape = false;
// create a table that contains the string as the value
lua_createtable(L, 1, 0);
lua_pushvalue(L, 1);
lua_rawseti(L, -2, 1);
lua_replace(L, 1);
}
luaL_checktype(L, 1, LUA_TTABLE);
#if LUA_VERSION_NUM > 501
lua_len(L, 1);
#else
@ -354,36 +598,15 @@ static int process_start(lua_State* L) {
#endif
cmd_len = luaL_checknumber(L, -1); lua_pop(L, 1);
if (!cmd_len)
// we have not allocated anything here yet, so we can skip cleanup code
// don't do this anywhere else!
return luaL_argerror(L, 1, "table cannot be empty");
// check if each arguments is a string
for (size_t i = 1; i <= cmd_len; ++i) {
lua_pushinteger(L, i);
lua_rawget(L, 1);
cmd[i-1] = luaL_checkstring(L, -1);
}
} else {
literal = true;
cmd[0] = luaL_checkstring(L, 1);
cmd_len = 1;
lua_rawgeti(L, 1, i);
luaL_checkstring(L, -1);
lua_pop(L, 1);
}
if (arg_len > 1) {
lua_getfield(L, 2, "env");
if (!lua_isnil(L, -1)) {
lua_pushnil(L);
while (lua_next(L, -2) != 0) {
const char* key = luaL_checklstring(L, -2, &key_len);
const char* val = luaL_checklstring(L, -1, &val_len);
env_names[env_len] = malloc(key_len+1);
strcpy((char*)env_names[env_len], key);
env_values[env_len] = malloc(val_len+1);
strcpy((char*)env_values[env_len], val);
lua_pop(L, 1);
++env_len;
}
} else
lua_pop(L, 1);
if (lua_istable(L, 2)) {
lua_getfield(L, 2, "detach"); detach = lua_toboolean(L, -1);
lua_getfield(L, 2, "timeout"); deadline = luaL_optnumber(L, -1, deadline);
lua_getfield(L, 2, "cwd"); cwd = luaL_optstring(L, -1, NULL);
@ -391,12 +614,55 @@ static int process_start(lua_State* L) {
lua_getfield(L, 2, "stdout"); new_fds[STDOUT_FD] = luaL_optnumber(L, -1, STDOUT_FD);
lua_getfield(L, 2, "stderr"); new_fds[STDERR_FD] = luaL_optnumber(L, -1, STDERR_FD);
for (int stream = STDIN_FD; stream <= STDERR_FD; ++stream) {
if (new_fds[stream] > STDERR_FD || new_fds[stream] < REDIRECT_PARENT) {
lua_pushfstring(L, "error: redirect to handles, FILE* and paths are not supported");
if (new_fds[stream] > STDERR_FD || new_fds[stream] < REDIRECT_PARENT)
return luaL_error(L, "error: redirect to handles, FILE* and paths are not supported");
}
lua_pop(L, 6); // pop all the values above
luaL_getsubtable(L, 2, "env");
// count environment variobles
lua_pushnil(L);
while (lua_next(L, -2) != 0) {
luaL_checkstring(L, -2);
luaL_checkstring(L, -1);
lua_pop(L, 1);
env_len++;
}
if (env_len) {
if ((r = process_env_init(&env_vars, &env_vars_len, env_len)) != 0) {
retval = -1;
push_error(L, "cannot allocate environment list", r);
goto cleanup;
}
lua_pushnil(L);
while (lua_next(L, -2) != 0) {
if ((r = process_env_add(&env_vars, &env_vars_len, lua_tostring(L, -2), lua_tostring(L, -1))) != 0) {
retval = -1;
push_error(L, "cannot copy environment variable", r);
goto cleanup;
}
lua_pop(L, 1);
env_len++;
}
}
}
// allocate and copy commands
if ((r = process_arglist_init(&arglist, &arglist_len, cmd_len)) != 0) {
retval = -1;
push_error(L, "cannot create argument list", r);
goto cleanup;
}
for (size_t i = 1; i <= cmd_len; i++) {
lua_rawgeti(L, 1, i);
if ((r = process_arglist_add(&arglist, &arglist_len, lua_tostring(L, -1), escape)) != 0) {
retval = -1;
push_error(L, "cannot add argument", r);
goto cleanup;
}
lua_pop(L, 1);
}
process_t* self = lua_newuserdata(L, sizeof(process_t));
@ -405,6 +671,13 @@ static int process_start(lua_State* L) {
self->deadline = deadline;
self->detached = detach;
#if _WIN32
if (env_vars) {
if ((r = process_env_add_system(&env_vars, &env_vars_len)) != 0) {
retval = -1;
push_error(L, "cannot add environment variable", r);
goto cleanup;
}
}
for (int i = 0; i < 3; ++i) {
switch (new_fds[i]) {
case REDIRECT_PARENT:
@ -455,7 +728,7 @@ static int process_start(lua_State* L) {
self->child_pipes[i][1] = self->child_pipes[new_fds[i]][1];
}
}
STARTUPINFO siStartInfo;
STARTUPINFOW siStartInfo;
memset(&self->process_information, 0, sizeof(self->process_information));
memset(&siStartInfo, 0, sizeof(siStartInfo));
siStartInfo.cb = sizeof(siStartInfo);
@ -463,48 +736,10 @@ static int process_start(lua_State* L) {
siStartInfo.hStdInput = self->child_pipes[STDIN_FD][0];
siStartInfo.hStdOutput = self->child_pipes[STDOUT_FD][1];
siStartInfo.hStdError = self->child_pipes[STDERR_FD][1];
char commandLine[32767] = { 0 }, environmentBlock[32767], wideEnvironmentBlock[32767*2];
int offset = 0;
if (!literal) {
for (size_t i = 0; i < cmd_len; ++i) {
size_t len = strlen(cmd[i]);
if (offset + len + 2 >= sizeof(commandLine)) break;
if (i > 0)
commandLine[offset++] = ' ';
commandLine[offset++] = '"';
int backslashCount = 0; // Yes, this is necessary.
for (size_t j = 0; j < len && offset + 2 + backslashCount < sizeof(commandLine); ++j) {
if (cmd[i][j] == '\\')
++backslashCount;
else if (cmd[i][j] == '"') {
for (size_t k = 0; k < backslashCount; ++k)
commandLine[offset++] = '\\';
commandLine[offset++] = '\\';
backslashCount = 0;
} else
backslashCount = 0;
commandLine[offset++] = cmd[i][j];
}
if (offset + 1 + backslashCount >= sizeof(commandLine)) break;
for (size_t k = 0; k < backslashCount; ++k)
commandLine[offset++] = '\\';
commandLine[offset++] = '"';
}
commandLine[offset] = 0;
} else {
strncpy(commandLine, cmd[0], sizeof(commandLine));
}
offset = 0;
for (size_t i = 0; i < env_len; ++i) {
if (offset + strlen(env_values[i]) + strlen(env_names[i]) + 1 >= sizeof(environmentBlock))
break;
offset += snprintf(&environmentBlock[offset], sizeof(environmentBlock) - offset, "%s=%s", env_names[i], env_values[i]);
environmentBlock[offset++] = 0;
}
environmentBlock[offset++] = 0;
if (env_len > 0)
MultiByteToWideChar(CP_UTF8, MB_PRECOMPOSED, environmentBlock, offset, (LPWSTR)wideEnvironmentBlock, sizeof(wideEnvironmentBlock));
if (!CreateProcess(NULL, commandLine, NULL, NULL, true, (detach ? DETACHED_PROCESS : CREATE_NO_WINDOW) | CREATE_UNICODE_ENVIRONMENT, env_len > 0 ? wideEnvironmentBlock : NULL, cwd, &siStartInfo, &self->process_information)) {
wchar_t cwd_w[MAX_PATH];
if (cwd) // TODO: error handling
MultiByteToWideChar(CP_UTF8, 0, cwd, -1, cwd_w, MAX_PATH);
if (!CreateProcessW(NULL, arglist, NULL, NULL, true, (detach ? DETACHED_PROCESS : CREATE_NO_WINDOW) | CREATE_UNICODE_ENVIRONMENT, env_vars, cwd ? cwd_w : NULL, &siStartInfo, &self->process_information)) {
push_error(L, NULL, GetLastError());
retval = -1;
goto cleanup;
@ -552,9 +787,9 @@ static int process_start(lua_State* L) {
close(self->child_pipes[stream][stream == STDIN_FD ? 1 : 0]);
}
size_t set;
for (set = 0; set < env_len && setenv(env_names[set], env_values[set], 1) == 0; ++set);
if (set == env_len && (!detach || setsid() != -1) && (!cwd || chdir(cwd) != -1))
execvp(cmd[0], (char** const)cmd);
for (set = 0; set < env_vars_len && setenv(env_vars[set], env_vars[set+1], 1) == 0; set += 2);
if (set == env_vars_len && (!detach || setsid() != -1) && (!cwd || chdir(cwd) != -1))
execvp(arglist[0], (char** const)arglist);
write(control_pipe[1], &errno, sizeof(errno));
_exit(-1);
}
@ -588,16 +823,15 @@ static int process_start(lua_State* L) {
if (control_pipe[0]) close(control_pipe[0]);
if (control_pipe[1]) close(control_pipe[1]);
#endif
for (size_t i = 0; i < env_len; ++i) {
free((char*)env_names[i]);
free((char*)env_values[i]);
}
for (int stream = 0; stream < 3; ++stream) {
process_stream_t* pipe = &self->child_pipes[stream][stream == STDIN_FD ? 0 : 1];
if (*pipe) {
close_fd(pipe);
}
}
process_arglist_free(&arglist);
process_env_free(&env_vars);
if (retval == -1)
return lua_error(L);