From 7111b8a6c93d14a922458a6b3bd43deff18ed558 Mon Sep 17 00:00:00 2001 From: Takase <20792268+takase1121@users.noreply.github.com> Date: Thu, 30 Nov 2023 23:33:24 +0800 Subject: [PATCH] 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 --- src/api/process.c | 422 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 328 insertions(+), 94 deletions(-) diff --git a/src/api/process.c b/src/api/process.c index d7bfeb72..66f27536 100644 --- a/src/api/process.c +++ b/src/api/process.c @@ -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; @@ -339,51 +349,264 @@ static bool signal_process(process_t* proc, signal_e sig) { return true; } -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 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_VERSION_NUM > 501 - lua_len(L, 1); - #else - lua_pushinteger(L, (int)lua_objlen(L, 1)); - #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"); - for (size_t i = 1; i <= cmd_len; ++i) { - lua_pushinteger(L, i); - lua_rawget(L, 1); - cmd[i-1] = luaL_checkstring(L, -1); - } + +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 { - literal = true; - cmd[0] = luaL_checkstring(L, 1); - cmd_len = 1; + // 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 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 }; + + 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); } - 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); + luaL_checktype(L, 1, LUA_TTABLE); + #if LUA_VERSION_NUM > 501 + lua_len(L, 1); + #else + lua_pushinteger(L, (int)lua_objlen(L, 1)); + #endif + cmd_len = luaL_checknumber(L, -1); lua_pop(L, 1); + if (!cmd_len) + 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_rawgeti(L, 1, i); + luaL_checkstring(L, -1); + 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); @@ -391,20 +614,70 @@ 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)); memset(self, 0, sizeof(process_t)); luaL_setmetatable(L, API_TYPE_PROCESS); 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);