summaryrefslogtreecommitdiff
path: root/shared/process-util.c
blob: e36c64709bb351c98355d2355403b807a7d5c8a2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
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 <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++) {
		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;
}