weston/shared/process-util.c

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/*
* 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 <assert.h>
#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wayland-util.h>
#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++) {
if (s->fds[i] >= 0)
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;
}