From: Marius Vlad Date: Mon, 19 Sep 2022 19:57:13 +0000 (+0300) Subject: process-util: Move Xwayland fork helpers to shared X-Git-Tag: 17.90.0~69 X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=commitdiff_plain;h=edb6d397a4c6e66aff8227bdd0f7f42ff07203f9;p=src%2Fagl-compositor.git process-util: Move Xwayland fork helpers to shared We'll want to reuse these inside desktop-shell as well as the Weston frontend. (Based on the work from https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/954) Bug-AGL: SPEC-4510 Signed-off-by: Daniel Stone Signed-off-by: Marius Vlad Change-Id: Ife13dce545928cf53e4f49a657b756ed88ee742f --- diff --git a/shared/process-util.c b/shared/process-util.c new file mode 100644 index 0000000..e36c647 --- /dev/null +++ b/shared/process-util.c @@ -0,0 +1,270 @@ +/* + * Copyright 2022 Collabora, Ltd. + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial + * portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "config.h" + +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "helpers.h" +#include "os-compatibility.h" +#include "process-util.h" +#include "string-helpers.h" + +extern char **environ; /* defined by libc */ + +void +fdstr_update_str1(struct fdstr *s) +{ + snprintf(s->str1, sizeof(s->str1), "%d", s->fds[1]); +} + +void +fdstr_set_fd1(struct fdstr *s, int fd) +{ + s->fds[0] = -1; + s->fds[1] = fd; + fdstr_update_str1(s); +} + +bool +fdstr_clear_cloexec_fd1(struct fdstr *s) +{ + return os_fd_clear_cloexec(s->fds[1]) >= 0; +} + +void +fdstr_close_all(struct fdstr *s) +{ + unsigned i; + + for (i = 0; i < ARRAY_LENGTH(s->fds); i++) { + close(s->fds[i]); + s->fds[i] = -1; + } +} + +void +custom_env_init_from_environ(struct custom_env *env) +{ + char **it; + char **ep; + + wl_array_init(&env->envp); + env->env_finalized = false; + wl_array_init(&env->argp); + env->arg_finalized = false; + + for (it = environ; *it; it++) { + ep = wl_array_add(&env->envp, sizeof *ep); + assert(ep); + *ep = strdup(*it); + assert(*ep); + } +} + +void +custom_env_fini(struct custom_env *env) +{ + char **p; + + wl_array_for_each(p, &env->envp) + free(*p); + wl_array_release(&env->envp); + + wl_array_for_each(p, &env->argp) + free(*p); + wl_array_release(&env->argp); +} + +static char ** +custom_env_get_env_var(struct custom_env *env, const char *name) +{ + char **ep; + size_t name_len = strlen(name); + + wl_array_for_each(ep, &env->envp) { + char *entry = *ep; + + if (strncmp(entry, name, name_len) == 0 && + entry[name_len] == '=') { + return ep; + } + } + + return NULL; +} + +void +custom_env_add_arg(struct custom_env *env, const char *arg) +{ + char **ap; + + assert(!env->arg_finalized); + + ap = wl_array_add(&env->argp, sizeof *ap); + assert(ap); + + *ap = strdup(arg); + assert(*ap); +} + +void +custom_env_set_env_var(struct custom_env *env, const char *name, const char *value) +{ + char **ep; + + assert(strchr(name, '=') == NULL); + assert(!env->env_finalized); + + ep = custom_env_get_env_var(env, name); + if (ep) + free(*ep); + else + ep = wl_array_add(&env->envp, sizeof *ep); + assert(ep); + + str_printf(ep, "%s=%s", name, value); + assert(*ep); +} + +/** + * Add information from a parsed exec string to a custom_env + * + * An 'exec string' is a string in the format: + * ENVFOO=bar ENVBAR=baz /path/to/exec --arg anotherarg + * + * This function will parse such a string and add the specified environment + * variables (in the format KEY=value) up until it sees a non-environment + * string, after which point every entry will be interpreted as a new + * argument. + * + * Entries are space-separated; there is no support for quoting. + */ +void +custom_env_add_from_exec_string(struct custom_env *env, const char *exec_str) +{ + char *dup_path = strdup(exec_str); + char *start = dup_path; + + assert(dup_path); + + /* Build the environment array (if any) by handling any number of + * equal-separated key=value at the start of the string, split by + * spaces; uses "foo=bar baz=quux meh argh" as the example, where + * "foo=bar" and "baz=quux" should go into the environment, and + * "meh" should be executed with "argh" as its first argument */ + while (*start) { + char *k = NULL, *v = NULL; + char *p; + + /* Leaves us with "foo\0bar baz=quux meh argh", with k pointing + * to "foo" and v pointing to "bar baz=quux meh argh" */ + for (p = start; *p && !isspace(*p); p++) { + if (*p == '=') { + *p++ = '\0'; + k = start; + v = p; + break; + } + } + + if (!v) + break; + + /* Walk to the next space or NUL, filling any trailing spaces + * with NUL, to give us "foo\0bar\0\0baz=quux meh argh". + * k will point to "foo", v will point to "bar", and + * start will point to "baz=quux meh argh". */ + while (*p && !isspace(*p)) + p++; + while (*p && isspace(*p)) + *p++ = '\0'; + start = p; + + custom_env_set_env_var(env, k, v); + } + + /* Now build the argv array by splitting on spaces */ + while (*start) { + char *p; + bool valid = false; + + for (p = start; *p && !isspace(*p); p++) + valid = true; + + if (!valid) + break; + + while (*p && isspace(*p)) + *p++ = '\0'; + + custom_env_add_arg(env, start); + start = p; + } + + free(dup_path); +} + +char *const * +custom_env_get_envp(struct custom_env *env) +{ + char **ep; + + assert(!env->env_finalized); + + /* add terminating NULL */ + ep = wl_array_add(&env->envp, sizeof *ep); + assert(ep); + *ep = NULL; + + env->env_finalized = true; + + return env->envp.data; +} + +char *const * +custom_env_get_argp(struct custom_env *env) +{ + char **ap; + + assert(!env->arg_finalized); + + /* add terminating NULL */ + ap = wl_array_add(&env->argp, sizeof *ap); + assert(ap); + *ap = NULL; + + env->arg_finalized = true; + + return env->argp.data; +} diff --git a/shared/process-util.h b/shared/process-util.h new file mode 100644 index 0000000..05543f6 --- /dev/null +++ b/shared/process-util.h @@ -0,0 +1,94 @@ +/* + * Copyright 2022 Collabora, Ltd. + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial + * portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include +#include +#include +#include + +#include + +#include "os-compatibility.h" +#include "string-helpers.h" + +/** + * A container for file descriptors and their string representations, designed + * to be used when forking child processes. + * + * fds[0] is generally used as the file descriptor held within the parent + * process to communicate with the child, and fds[1] as the child's counterpart. + * + * str1[] is used as a string representation of fds[1]. + */ +struct fdstr { + char str1[12]; + int fds[2]; +}; + +void +fdstr_update_str1(struct fdstr *s); + +void +fdstr_set_fd1(struct fdstr *s, int fd); + +bool +fdstr_clear_cloexec_fd1(struct fdstr *s); + +void +fdstr_close_all(struct fdstr *s); + + +/** + * A container for environment variables and/or process arguments, designed to + * be used when forking child processes, as setenv() and anything which + * allocates memory cannot be used between fork() and exec(). + */ +struct custom_env { + struct wl_array envp; + bool env_finalized; + struct wl_array argp; + bool arg_finalized; +}; + +void +custom_env_init_from_environ(struct custom_env *env); + +void +custom_env_fini(struct custom_env *env); + +void +custom_env_set_env_var(struct custom_env *env, const char *name, const char *value); + +void +custom_env_add_arg(struct custom_env *env, const char *arg); + +void +custom_env_add_from_exec_string(struct custom_env *env, const char *exec_str); + +char *const * +custom_env_get_envp(struct custom_env *env); + +char *const * +custom_env_get_argp(struct custom_env *env);