summaryrefslogtreecommitdiff
path: root/src/proc_open.c
blob: ad2650d20178a5571e789392f3a252f5b0aad678 (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
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include "proc_open.h"

#ifdef WIN32
#include <io.h>
#include <fcntl.h>
#else
#include <sys/wait.h>
#include <unistd.h>
#endif


#ifdef WIN32
/* {{{ win32 stuff */
# define SHELLENV "ComSpec"
# define SECURITY_DC , SECURITY_ATTRIBUTES *security
# define SECURITY_CC , security
# define pipe(pair) (CreatePipe(&pair[0], &pair[1], security, 2048L) ? 0 : -1)
static inline HANDLE dup_handle(HANDLE src, BOOL inherit, BOOL closeorig)
{
	HANDLE copy, self = GetCurrentProcess();

	if (!DuplicateHandle(self, src, self, &copy, 0, inherit, DUPLICATE_SAME_ACCESS |
				(closeorig ? DUPLICATE_CLOSE_SOURCE : 0)))
		return NULL;
	return copy;
}
# define close_descriptor(fd) CloseHandle(fd)
static void pipe_close_parent(pipe_t *p) {
	/* don't let the child inherit the parent side of the pipe */
	p->parent = dup_handle(p->parent, FALSE, TRUE);
}
static void pipe_close_child(pipe_t *p) {
	close_descriptor(p->child);
	p->fd = _open_osfhandle((long)p->parent,
			(p->fd == 0 ? O_RDONLY : O_WRONLY)|O_BINARY);
}
/* }}} */
#else /* WIN32 */
/* {{{ unix way */
# define SHELLENV "SHELL"
# define SECURITY_DC
# define SECURITY_CC
# define close_descriptor(fd) close(fd)
static void pipe_close_parent(pipe_t *p) {
	/* don't close stdin */
	close_descriptor(p->parent);
	if (dup2(p->child, p->fd) != p->fd) {
		perror("pipe_child dup2");
	} else {
		close_descriptor(p->child);
		p->child = p->fd;
	}
}
static void pipe_close_child(pipe_t *p) {
	close_descriptor(p->child);
	p->fd = p->parent;
}
/* }}} */
#endif /* WIN32 */

/* {{{ pipe_close */
static void pipe_close(pipe_t *p) {
	close_descriptor(p->parent);
	close_descriptor(p->child);
#ifdef WIN32
	close(p->fd);
#endif
}
/* }}} */
/* {{{ pipe_open */
static int pipe_open(pipe_t *p, int fd SECURITY_DC) {
	descriptor_t newpipe[2];

	if (0 != pipe(newpipe)) {
		fprintf(stderr, "can't open pipe");
		return -1;
	}
	if (0 == fd) {
		p->parent = newpipe[1]; /* write */
		p->child  = newpipe[0]; /* read */
	} else {
		p->parent = newpipe[0]; /* read */
		p->child  = newpipe[1]; /* write */
	}
	p->fd = fd;

	return 0;
}
/* }}} */

/* {{{ proc_open_pipes */
static int proc_open_pipes(proc_handler_t *proc SECURITY_DC) {
	if (pipe_open(&(proc->in), 0 SECURITY_CC) != 0) {
		return -1;
	}
	if (pipe_open(&(proc->out), 1 SECURITY_CC) != 0) {
		return -1;
	}
	if (pipe_open(&(proc->err), 2 SECURITY_CC) != 0) {
		return -1;
	}
	return 0;
}
/* }}} */
/* {{{ proc_close_pipes */
static void proc_close_pipes(proc_handler_t *proc) {
	pipe_close(&proc->in);
	pipe_close(&proc->out);
	pipe_close(&proc->err);
}
/* }}} */
/* {{{ proc_close_parents */
static void proc_close_parents(proc_handler_t *proc) {
	pipe_close_parent(&proc->in);
	pipe_close_parent(&proc->out);
	pipe_close_parent(&proc->err);
}
/* }}} */
/* {{{ proc_close_childs */
static void proc_close_childs(proc_handler_t *proc) {
	pipe_close_child(&proc->in);
	pipe_close_child(&proc->out);
	pipe_close_child(&proc->err);
}
/* }}} */

#ifdef WIN32
/* {{{ proc_close */
int proc_close(proc_handler_t *proc) {
	proc_pid_t child = proc->child;
	DWORD wstatus;

	proc_close_pipes(proc);
	WaitForSingleObject(child, INFINITE);
	GetExitCodeProcess(child, &wstatus);
	CloseHandle(child);

	return wstatus;
}
/* }}} */
/* {{{ proc_open */
int proc_open(proc_handler_t *proc, const char *command) {
	PROCESS_INFORMATION pi;
	STARTUPINFO si;
	BOOL procok;
	SECURITY_ATTRIBUTES security;
	const char *shell = NULL;
	const char *windir = NULL;
	buffer *cmdline;

	if (NULL == (shell = getenv(SHELLENV)) &&
			NULL == (windir = getenv("SystemRoot")) &&
			NULL == (windir = getenv("windir"))) {
		fprintf(stderr, "One of %s,%%SystemRoot,%%windir is required", SHELLENV);
		return -1;
	}

	/* we use this to allow the child to inherit handles */
	memset(&security, 0, sizeof(security));
	security.nLength = sizeof(security);
	security.bInheritHandle = TRUE;
	security.lpSecurityDescriptor = NULL;

	if (proc_open_pipes(proc, &security) != 0) {
		return -1;
	}
	proc_close_parents(proc);

	memset(&si, 0, sizeof(si));
	si.cb = sizeof(si);
	si.dwFlags = STARTF_USESTDHANDLES;
	si.hStdInput = proc->in.child;
	si.hStdOutput = proc->out.child;
	si.hStdError = proc->err.child;

	memset(&pi, 0, sizeof(pi));

	cmdline = buffer_init();
	if (shell) {
		buffer_append_string(cmdline, shell);
	} else {
		buffer_append_string(cmdline, windir);
		buffer_append_string(cmdline, "\\system32\\cmd.exe");
	}
	buffer_append_string_len(cmdline, CONST_STR_LEN(" /c "));
	buffer_append_string(cmdline, command);
	procok = CreateProcess(NULL, cmdline->ptr, &security, &security, TRUE,
			NORMAL_PRIORITY_CLASS, NULL, NULL, &si, &pi);

	if (FALSE == procok) {
		fprintf(stderr, "failed to CreateProcess: %s", cmdline->ptr);
		buffer_free(cmdline);
		return -1;
	}
	buffer_free(cmdline);

	proc->child = pi.hProcess;
	CloseHandle(pi.hThread);

	proc_close_childs(proc);

	return 0;
}
/* }}} */
#else /* WIN32 */
/* {{{ proc_close */
int proc_close(proc_handler_t *proc) {
	pid_t child = proc->child;
	int wstatus;
	pid_t wait_pid;

	proc_close_pipes(proc);

	do {
		wait_pid = waitpid(child, &wstatus, 0);
	} while (wait_pid == -1 && errno == EINTR);

	if (wait_pid == -1) {
		return -1;
	} else {
		if (WIFEXITED(wstatus))
			wstatus = WEXITSTATUS(wstatus);
	}

	return wstatus;
}
/* }}} */
/* {{{ proc_open */
int proc_open(proc_handler_t *proc, const char *command) {
	pid_t child;
	const char *shell;

	if (NULL == (shell = getenv(SHELLENV))) {
		shell = "/bin/sh";
	}

	if (proc_open_pipes(proc) != 0) {
		return -1;
	}

	/* the unix way */

	child = fork();

	if (child == 0) {
		/* this is the child process */

		/* close those descriptors that we just opened for the parent stuff,
		 * dup new descriptors into required descriptors and close the original
		 * cruft
		 */
		proc_close_parents(proc);

		execl(shell, shell, "-c", command, NULL);
		_exit(127);

	} else if (child < 0) {
		fprintf(stderr, "failed to forking");
		proc_close(proc);
		return -1;

	} else {
		proc->child = child;
		proc_close_childs(proc);
		return 0;
	}
}
/* }}} */
#endif /* WIN32 */

/* {{{ proc_read_fd_to_buffer */
static void proc_read_fd_to_buffer(int fd, buffer *b) {
	ssize_t s;

	for (;;) {
		buffer_prepare_append(b, 512);
		if ((s = read(fd, (void *)(b->ptr + b->used), 512 - 1)) <= 0) {
			break;
		}
		b->used += s;
	}
	b->ptr[b->used] = '\0';
}
/* }}} */
/* {{{ proc_open_buffer */
int proc_open_buffer(proc_handler_t *proc, const char *command, buffer *in, buffer *out, buffer *err) {

	UNUSED(err);

	if (proc_open(proc, command) != 0) {
		return -1;
	}

	if (in) {
		if (write(proc->in.fd, (void *)in->ptr, in->used) < 0) {
			perror("error writing pipe");
			return -1;
		}
	}
	pipe_close(&proc->in);

	if (out) {
		proc_read_fd_to_buffer(proc->out.fd, out);
	}
	pipe_close(&proc->out);

	if (err) {
		proc_read_fd_to_buffer(proc->err.fd, err);
	}
	pipe_close(&proc->err);

	return 0;
}
/* }}} */

/* {{{ test */
#ifdef DEBUG_PROC_OPEN
int main() {
	proc_handler_t proc;
	buffer *in = buffer_init(), *out = buffer_init(), *err = buffer_init();
	int wstatus;

#define FREE() do { \
	buffer_free(in); \
	buffer_free(out); \
	buffer_free(err); \
} while (0)

#define RESET() do { \
	buffer_reset(in); \
	buffer_reset(out); \
	buffer_reset(err); \
	wstatus = proc_close(&proc); \
	if (0&&wstatus != 0) { \
		fprintf(stdout, "exitstatus %d\n", wstatus); \
		return __LINE__ - 200; \
	} \
} while (0)

#define ERROR_OUT() do { \
	fprintf(stdout, "failed opening proc\n"); \
	wstatus = proc_close(&proc); \
	fprintf(stdout, "exitstatus %d\n", wstatus); \
	FREE(); \
	return __LINE__ - 300; \
} while (0)

#ifdef WIN32
#define CMD_CAT "pause"
#else
#define CMD_CAT "cat"
#endif

	do {
		fprintf(stdout, "test: echo 123 without read\n");
		if (proc_open(&proc, "echo 321") != 0) {
			ERROR_OUT();
		}
		close_descriptor(proc.in.parent);
		close_descriptor(proc.out.parent);
		close_descriptor(proc.err.parent);
		RESET();

		fprintf(stdout, "test: echo 321 with read\n"); fflush(stdout);
		if (proc_open_buffer(&proc, "echo 321", NULL, out, err) != 0) {
			ERROR_OUT();
		}
		fprintf(stdout, "result: ->%s<-\n\n", out->ptr); fflush(stdout);
		RESET();

		fprintf(stdout, "test: echo 123 | " CMD_CAT "\n"); fflush(stdout);
		buffer_copy_string_len(in, CONST_STR_LEN("123\n"));
		if (proc_open_buffer(&proc, CMD_CAT, in, out, err) != 0) {
			ERROR_OUT();
		}
		fprintf(stdout, "result: ->%s<-\n\n", out->ptr); fflush(stdout);
		RESET();
	} while (0);

#undef RESET
#undef ERROR_OUT

	fprintf(stdout, "ok\n");

	FREE();
	return 0;
}
#endif /* DEBUG_PROC_OPEN */
/* }}} */