xref: /openbsd/usr.bin/tmux/file.c (revision 09467b48)
1 /* $OpenBSD: file.c,v 1.7 2020/05/26 08:41:47 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/uio.h>
22 
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <imsg.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 
31 #include "tmux.h"
32 
33 static int	file_next_stream = 3;
34 
35 RB_GENERATE(client_files, client_file, entry, file_cmp);
36 
37 static char *
38 file_get_path(struct client *c, const char *file)
39 {
40 	char	*path;
41 
42 	if (*file == '/')
43 		path = xstrdup(file);
44 	else
45 		xasprintf(&path, "%s/%s", server_client_get_cwd(c, NULL), file);
46 	return (path);
47 }
48 
49 int
50 file_cmp(struct client_file *cf1, struct client_file *cf2)
51 {
52 	if (cf1->stream < cf2->stream)
53 		return (-1);
54 	if (cf1->stream > cf2->stream)
55 		return (1);
56 	return (0);
57 }
58 
59 struct client_file *
60 file_create(struct client *c, int stream, client_file_cb cb, void *cbdata)
61 {
62 	struct client_file	*cf;
63 
64 	cf = xcalloc(1, sizeof *cf);
65 	cf->c = c;
66 	cf->references = 1;
67 	cf->stream = stream;
68 
69 	cf->buffer = evbuffer_new();
70 	if (cf->buffer == NULL)
71 		fatalx("out of memory");
72 
73 	cf->cb = cb;
74 	cf->data = cbdata;
75 
76 	if (cf->c != NULL) {
77 		RB_INSERT(client_files, &cf->c->files, cf);
78 		cf->c->references++;
79 	}
80 
81 	return (cf);
82 }
83 
84 void
85 file_free(struct client_file *cf)
86 {
87 	if (--cf->references != 0)
88 		return;
89 
90 	evbuffer_free(cf->buffer);
91 	free(cf->path);
92 
93 	if (cf->c != NULL) {
94 		RB_REMOVE(client_files, &cf->c->files, cf);
95 		server_client_unref(cf->c);
96 	}
97 	free(cf);
98 }
99 
100 static void
101 file_fire_done_cb(__unused int fd, __unused short events, void *arg)
102 {
103 	struct client_file	*cf = arg;
104 	struct client		*c = cf->c;
105 
106 	if (cf->cb != NULL && (c == NULL || (~c->flags & CLIENT_DEAD)))
107 		cf->cb(c, cf->path, cf->error, 1, cf->buffer, cf->data);
108 	file_free(cf);
109 }
110 
111 void
112 file_fire_done(struct client_file *cf)
113 {
114 	event_once(-1, EV_TIMEOUT, file_fire_done_cb, cf, NULL);
115 }
116 
117 void
118 file_fire_read(struct client_file *cf)
119 {
120 	struct client	*c = cf->c;
121 
122 	if (cf->cb != NULL)
123 		cf->cb(c, cf->path, cf->error, 0, cf->buffer, cf->data);
124 }
125 
126 int
127 file_can_print(struct client *c)
128 {
129 	if (c == NULL)
130 		return (0);
131 	if (c->session != NULL && (~c->flags & CLIENT_CONTROL))
132 		return (0);
133 	return (1);
134 }
135 
136 void
137 file_print(struct client *c, const char *fmt, ...)
138 {
139 	va_list	ap;
140 
141 	va_start(ap, fmt);
142 	file_vprint(c, fmt, ap);
143 	va_end(ap);
144 }
145 
146 void
147 file_vprint(struct client *c, const char *fmt, va_list ap)
148 {
149 	struct client_file	 find, *cf;
150 	struct msg_write_open	 msg;
151 
152 	if (!file_can_print(c))
153 		return;
154 
155 	find.stream = 1;
156 	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) {
157 		cf = file_create(c, 1, NULL, NULL);
158 		cf->path = xstrdup("-");
159 
160 		evbuffer_add_vprintf(cf->buffer, fmt, ap);
161 
162 		msg.stream = 1;
163 		msg.fd = STDOUT_FILENO;
164 		msg.flags = 0;
165 		proc_send(c->peer, MSG_WRITE_OPEN, -1, &msg, sizeof msg);
166 	} else {
167 		evbuffer_add_vprintf(cf->buffer, fmt, ap);
168 		file_push(cf);
169 	}
170 }
171 
172 void
173 file_print_buffer(struct client *c, void *data, size_t size)
174 {
175 	struct client_file	 find, *cf;
176 	struct msg_write_open	 msg;
177 
178 	if (!file_can_print(c))
179 		return;
180 
181 	find.stream = 1;
182 	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) {
183 		cf = file_create(c, 1, NULL, NULL);
184 		cf->path = xstrdup("-");
185 
186 		evbuffer_add(cf->buffer, data, size);
187 
188 		msg.stream = 1;
189 		msg.fd = STDOUT_FILENO;
190 		msg.flags = 0;
191 		proc_send(c->peer, MSG_WRITE_OPEN, -1, &msg, sizeof msg);
192 	} else {
193 		evbuffer_add(cf->buffer, data, size);
194 		file_push(cf);
195 	}
196 }
197 
198 void
199 file_error(struct client *c, const char *fmt, ...)
200 {
201 	struct client_file	 find, *cf;
202 	struct msg_write_open	 msg;
203 	va_list			 ap;
204 
205 	if (!file_can_print(c))
206 		return;
207 
208 	va_start(ap, fmt);
209 
210 	find.stream = 2;
211 	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) {
212 		cf = file_create(c, 2, NULL, NULL);
213 		cf->path = xstrdup("-");
214 
215 		evbuffer_add_vprintf(cf->buffer, fmt, ap);
216 
217 		msg.stream = 2;
218 		msg.fd = STDERR_FILENO;
219 		msg.flags = 0;
220 		proc_send(c->peer, MSG_WRITE_OPEN, -1, &msg, sizeof msg);
221 	} else {
222 		evbuffer_add_vprintf(cf->buffer, fmt, ap);
223 		file_push(cf);
224 	}
225 
226 	va_end(ap);
227 }
228 
229 void
230 file_write(struct client *c, const char *path, int flags, const void *bdata,
231     size_t bsize, client_file_cb cb, void *cbdata)
232 {
233 	struct client_file	*cf;
234 	FILE			*f;
235 	struct msg_write_open	*msg;
236 	size_t			 msglen;
237 	int			 fd = -1;
238 	const char		*mode;
239 
240 	if (strcmp(path, "-") == 0) {
241 		cf = file_create(c, file_next_stream++, cb, cbdata);
242 		cf->path = xstrdup("-");
243 
244 		fd = STDOUT_FILENO;
245 		if (c == NULL ||
246 		    (c->flags & CLIENT_ATTACHED) ||
247 		    (c->flags & CLIENT_CONTROL)) {
248 			cf->error = EBADF;
249 			goto done;
250 		}
251 		goto skip;
252 	}
253 
254 	cf = file_create(c, file_next_stream++, cb, cbdata);
255 	cf->path = file_get_path(c, path);
256 
257 	if (c == NULL || c->flags & CLIENT_ATTACHED) {
258 		if (flags & O_APPEND)
259 			mode = "ab";
260 		else
261 			mode = "wb";
262 		f = fopen(cf->path, mode);
263 		if (f == NULL) {
264 			cf->error = errno;
265 			goto done;
266 		}
267 		if (fwrite(bdata, 1, bsize, f) != bsize) {
268 			fclose(f);
269 			cf->error = EIO;
270 			goto done;
271 		}
272 		fclose(f);
273 		goto done;
274 	}
275 
276 skip:
277 	evbuffer_add(cf->buffer, bdata, bsize);
278 
279 	msglen = strlen(cf->path) + 1 + sizeof *msg;
280 	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
281 		cf->error = E2BIG;
282 		goto done;
283 	}
284 	msg = xmalloc(msglen);
285 	msg->stream = cf->stream;
286 	msg->fd = fd;
287 	msg->flags = flags;
288 	memcpy(msg + 1, cf->path, msglen - sizeof *msg);
289 	if (proc_send(c->peer, MSG_WRITE_OPEN, -1, msg, msglen) != 0) {
290 		free(msg);
291 		cf->error = EINVAL;
292 		goto done;
293 	}
294 	free(msg);
295 	return;
296 
297 done:
298 	file_fire_done(cf);
299 }
300 
301 void
302 file_read(struct client *c, const char *path, client_file_cb cb, void *cbdata)
303 {
304 	struct client_file	*cf;
305 	FILE			*f;
306 	struct msg_read_open	*msg;
307 	size_t			 msglen, size;
308 	int			 fd = -1;
309 	char			 buffer[BUFSIZ];
310 
311 	if (strcmp(path, "-") == 0) {
312 		cf = file_create(c, file_next_stream++, cb, cbdata);
313 		cf->path = xstrdup("-");
314 
315 		fd = STDIN_FILENO;
316 		if (c == NULL ||
317 		    (c->flags & CLIENT_ATTACHED) ||
318 		    (c->flags & CLIENT_CONTROL)) {
319 			cf->error = EBADF;
320 			goto done;
321 		}
322 		goto skip;
323 	}
324 
325 	cf = file_create(c, file_next_stream++, cb, cbdata);
326 	cf->path = file_get_path(c, path);
327 
328 	if (c == NULL || c->flags & CLIENT_ATTACHED) {
329 		f = fopen(cf->path, "rb");
330 		if (f == NULL) {
331 			cf->error = errno;
332 			goto done;
333 		}
334 		for (;;) {
335 			size = fread(buffer, 1, sizeof buffer, f);
336 			if (evbuffer_add(cf->buffer, buffer, size) != 0) {
337 				cf->error = ENOMEM;
338 				goto done;
339 			}
340 			if (size != sizeof buffer)
341 				break;
342 		}
343 		if (ferror(f)) {
344 			cf->error = EIO;
345 			goto done;
346 		}
347 		fclose(f);
348 		goto done;
349 	}
350 
351 skip:
352 	msglen = strlen(cf->path) + 1 + sizeof *msg;
353 	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
354 		cf->error = E2BIG;
355 		goto done;
356 	}
357 	msg = xmalloc(msglen);
358 	msg->stream = cf->stream;
359 	msg->fd = fd;
360 	memcpy(msg + 1, cf->path, msglen - sizeof *msg);
361 	if (proc_send(c->peer, MSG_READ_OPEN, -1, msg, msglen) != 0) {
362 		free(msg);
363 		cf->error = EINVAL;
364 		goto done;
365 	}
366 	free(msg);
367 	return;
368 
369 done:
370 	file_fire_done(cf);
371 }
372 
373 static void
374 file_push_cb(__unused int fd, __unused short events, void *arg)
375 {
376 	struct client_file	*cf = arg;
377 	struct client		*c = cf->c;
378 
379 	if (~c->flags & CLIENT_DEAD)
380 		file_push(cf);
381 	file_free(cf);
382 }
383 
384 void
385 file_push(struct client_file *cf)
386 {
387 	struct client		*c = cf->c;
388 	struct msg_write_data	*msg;
389 	size_t			 msglen, sent, left;
390 	struct msg_write_close	 close;
391 
392 	msg = xmalloc(sizeof *msg);
393 	left = EVBUFFER_LENGTH(cf->buffer);
394 	while (left != 0) {
395 		sent = left;
396 		if (sent > MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg)
397 			sent = MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg;
398 
399 		msglen = (sizeof *msg) + sent;
400 		msg = xrealloc(msg, msglen);
401 		msg->stream = cf->stream;
402 		memcpy(msg + 1, EVBUFFER_DATA(cf->buffer), sent);
403 		if (proc_send(c->peer, MSG_WRITE, -1, msg, msglen) != 0)
404 			break;
405 		evbuffer_drain(cf->buffer, sent);
406 
407 		left = EVBUFFER_LENGTH(cf->buffer);
408 		log_debug("%s: file %d sent %zu, left %zu", c->name, cf->stream,
409 		    sent, left);
410 	}
411 	if (left != 0) {
412 		cf->references++;
413 		event_once(-1, EV_TIMEOUT, file_push_cb, cf, NULL);
414 	} else if (cf->stream > 2) {
415 		close.stream = cf->stream;
416 		proc_send(c->peer, MSG_WRITE_CLOSE, -1, &close, sizeof close);
417 		file_fire_done(cf);
418 	}
419 	free(msg);
420 }
421