Blob


1 /*
2 * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
17 #include "compat.h"
19 #include <sys/types.h>
20 #include <sys/socket.h>
22 #include <netinet/in.h>
24 #include <assert.h>
25 #include <ctype.h>
26 #include <errno.h>
27 #include <netdb.h>
28 #include <stdarg.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <tls.h>
33 #include <unistd.h>
35 #if HAVE_ASR_RUN
36 # include <asr.h>
37 #endif
39 #include "telescope.h"
40 #include "utils.h"
42 static struct imsgev *iev_ui;
44 /* a pending request */
45 struct req {
46 struct phos_uri url;
47 uint32_t id;
48 int proto;
49 int fd;
50 struct tls *ctx;
51 char req[1024];
52 size_t len;
53 int done_header;
54 struct bufferevent *bev;
56 struct addrinfo *servinfo, *p;
57 #if HAVE_ASR_RUN
58 struct addrinfo hints;
59 struct event_asr *asrev;
60 #endif
62 TAILQ_ENTRY(req) reqs;
63 };
65 static struct req *req_by_id(uint32_t);
67 static void die(void) __attribute__((__noreturn__));
69 static void try_to_connect(int, short, void*);
71 #if HAVE_ASR_RUN
72 static void query_done(struct asr_result*, void*);
73 static void async_conn_towards(struct req*);
74 #else
75 static void blocking_conn_towards(struct req*);
76 #endif
78 static void close_with_err(struct req*, const char*);
79 static void close_with_errf(struct req*, const char*, ...)
80 __attribute__((format(printf, 2, 3)));
82 static void net_tls_handshake(int, short, void *);
83 static void net_tls_readcb(int, short, void *);
84 static void net_tls_writecb(int, short, void *);
86 static int gemini_parse_reply(struct req *, const char *, size_t);
88 static void net_ready(struct req *req);
89 static void net_read(struct bufferevent *, void *);
90 static void net_write(struct bufferevent *, void *);
91 static void net_error(struct bufferevent *, short, void *);
93 static void handle_get_raw(struct imsg *, size_t);
94 static void handle_cert_status(struct imsg*, size_t);
95 static void handle_proceed(struct imsg*, size_t);
96 static void handle_stop(struct imsg*, size_t);
97 static void handle_quit(struct imsg*, size_t);
98 static void handle_dispatch_imsg(int, short, void*);
100 static int net_send_ui(int, uint32_t, const void *, uint16_t);
102 /* TODO: making this customizable */
103 struct timeval timeout_for_handshake = { 5, 0 };
105 static imsg_handlerfn *handlers[] = {
106 [IMSG_GET_RAW] = handle_get_raw,
107 [IMSG_CERT_STATUS] = handle_cert_status,
108 [IMSG_PROCEED] = handle_proceed,
109 [IMSG_STOP] = handle_stop,
110 [IMSG_QUIT] = handle_quit,
111 };
113 typedef void (*statefn)(int, short, void*);
115 TAILQ_HEAD(, req) reqhead;
117 static inline void
118 yield_r(struct req *req, statefn fn, struct timeval *tv)
120 event_once(req->fd, EV_READ, fn, req, tv);
123 static inline void
124 yield_w(struct req *req, statefn fn, struct timeval *tv)
126 event_once(req->fd, EV_WRITE, fn, req, tv);
129 static struct req *
130 req_by_id(uint32_t id)
132 struct req *r;
134 TAILQ_FOREACH(r, &reqhead, reqs) {
135 if (r->id == id)
136 return r;
139 return NULL;
142 static void __attribute__((__noreturn__))
143 die(void)
145 abort(); /* TODO */
148 static void
149 try_to_connect(int fd, short ev, void *d)
151 struct req *req = d;
152 int error = 0;
153 socklen_t len = sizeof(error);
155 again:
156 if (req->p == NULL)
157 goto err;
159 if (req->fd != -1) {
160 if (getsockopt(req->fd, SOL_SOCKET, SO_ERROR, &error,
161 &len) == -1)
162 goto err;
163 if (error != 0) {
164 errno = error;
165 goto err;
167 goto done;
170 req->fd = socket(req->p->ai_family, req->p->ai_socktype,
171 req->p->ai_protocol);
172 if (req->fd == -1) {
173 req->p = req->p->ai_next;
174 goto again;
175 } else {
176 mark_nonblock(req->fd);
177 if (connect(req->fd, req->p->ai_addr, req->p->ai_addrlen) == 0)
178 goto done;
179 yield_w(req, try_to_connect, NULL);
181 return;
183 err:
184 freeaddrinfo(req->servinfo);
185 close_with_errf(req, "failed to connect to %s",
186 req->url.host);
187 return;
189 done:
190 freeaddrinfo(req->servinfo);
192 switch (req->proto) {
193 case PROTO_FINGER:
194 case PROTO_GOPHER:
195 /* finger and gopher don't have a header nor TLS */
196 req->done_header = 1;
197 net_ready(req);
198 break;
200 case PROTO_GEMINI: {
201 struct tls_config *conf;
203 if ((conf = tls_config_new()) == NULL)
204 die();
206 tls_config_insecure_noverifycert(conf);
207 tls_config_insecure_noverifyname(conf);
209 /* prepare tls */
210 if ((req->ctx = tls_client()) == NULL) {
211 close_with_errf(req, "tls_client: %s",
212 strerror(errno));
213 return;
216 if (tls_configure(req->ctx, conf) == -1) {
217 close_with_errf(req, "tls_configure: %s",
218 tls_error(req->ctx));
219 return;
221 tls_config_free(conf);
223 if (tls_connect_socket(req->ctx, req->fd, req->url.host)
224 == -1) {
225 close_with_errf(req, "tls_connect_socket: %s",
226 tls_error(req->ctx));
227 return;
229 yield_w(req, net_tls_handshake, &timeout_for_handshake);
230 break;
233 default:
234 die();
238 #if HAVE_ASR_RUN
239 static void
240 query_done(struct asr_result *res, void *d)
242 struct req *req = d;
244 req->asrev = NULL;
245 if (res->ar_gai_errno != 0) {
246 close_with_errf(req, "failed to resolve %s: %s",
247 req->url.host, gai_strerror(res->ar_gai_errno));
248 return;
251 req->fd = -1;
252 req->servinfo = res->ar_addrinfo;
253 req->p = res->ar_addrinfo;
254 try_to_connect(0, 0, req);
257 static void
258 async_conn_towards(struct req *req)
260 struct asr_query *q;
261 const char *proto = "1965";
263 if (*req->url.port != '\0')
264 proto = req->url.port;
266 req->hints.ai_family = AF_UNSPEC;
267 req->hints.ai_socktype = SOCK_STREAM;
268 q = getaddrinfo_async(req->url.host, proto, &req->hints, NULL);
269 req->asrev = event_asr_run(q, query_done, req);
271 #else
272 static void
273 blocking_conn_towards(struct req *req)
275 struct addrinfo hints;
276 struct phos_uri *url = &req->url;
277 int status;
278 const char *proto = "1965";
280 if (*url->port != '\0')
281 proto = url->port;
283 memset(&hints, 0, sizeof(hints));
284 hints.ai_family = AF_UNSPEC;
285 hints.ai_socktype = SOCK_STREAM;
287 if ((status = getaddrinfo(url->host, proto, &hints, &req->servinfo))) {
288 close_with_errf(req, "failed to resolve %s: %s",
289 url->host, gai_strerror(status));
290 return;
293 req->fd = -1;
294 req->p = req->servinfo;
295 try_to_connect(0, 0, req);
297 #endif
299 static void
300 close_conn(int fd, short ev, void *d)
302 struct req *req = d;
304 #if HAVE_ASR_RUN
305 if (req->asrev != NULL)
306 event_asr_abort(req->asrev);
307 #endif
309 if (req->bev != NULL) {
310 bufferevent_free(req->bev);
311 req->bev = NULL;
314 if (req->ctx != NULL) {
315 switch (tls_close(req->ctx)) {
316 case TLS_WANT_POLLIN:
317 yield_r(req, close_conn, NULL);
318 return;
319 case TLS_WANT_POLLOUT:
320 yield_w(req, close_conn, NULL);
321 return;
324 tls_free(req->ctx);
325 req->ctx = NULL;
328 TAILQ_REMOVE(&reqhead, req, reqs);
329 if (req->fd != -1)
330 close(req->fd);
331 free(req);
334 static void
335 close_with_err(struct req *req, const char *err)
337 net_send_ui(IMSG_ERR, req->id, err, strlen(err)+1);
338 close_conn(0, 0, req);
341 static void
342 close_with_errf(struct req *req, const char *fmt, ...)
344 va_list ap;
345 char *s;
347 va_start(ap, fmt);
348 if (vasprintf(&s, fmt, ap) == -1)
349 abort();
350 va_end(ap);
352 close_with_err(req, s);
353 free(s);
356 static void
357 net_tls_handshake(int fd, short event, void *d)
359 struct req *req = d;
360 const char *hash;
362 if (event == EV_TIMEOUT) {
363 close_with_err(req, "Timeout loading page");
364 return;
367 switch (tls_handshake(req->ctx)) {
368 case TLS_WANT_POLLIN:
369 yield_r(req, net_tls_handshake, NULL);
370 return;
371 case TLS_WANT_POLLOUT:
372 yield_w(req, net_tls_handshake, NULL);
373 return;
376 hash = tls_peer_cert_hash(req->ctx);
377 if (hash == NULL) {
378 close_with_errf(req, "handshake failed: %s",
379 tls_error(req->ctx));
380 return;
382 net_send_ui(IMSG_CHECK_CERT, req->id, hash, strlen(hash)+1);
385 static void
386 net_tls_readcb(int fd, short event, void *d)
388 struct bufferevent *bufev = d;
389 struct req *req = bufev->cbarg;
390 char buf[IBUF_READ_SIZE];
391 int what = EVBUFFER_READ;
392 int howmuch = IBUF_READ_SIZE;
393 int res;
394 ssize_t ret;
395 size_t len;
397 if (event == EV_TIMEOUT) {
398 what |= EVBUFFER_TIMEOUT;
399 goto err;
402 if (bufev->wm_read.high != 0)
403 howmuch = MIN(sizeof(buf), bufev->wm_read.high);
405 switch (ret = tls_read(req->ctx, buf, howmuch)) {
406 case TLS_WANT_POLLIN:
407 case TLS_WANT_POLLOUT:
408 goto retry;
409 case -1:
410 what |= EVBUFFER_ERROR;
411 goto err;
413 len = ret;
415 if (len == 0) {
416 what |= EVBUFFER_EOF;
417 goto err;
420 res = evbuffer_add(bufev->input, buf, len);
421 if (res == -1) {
422 what |= EVBUFFER_ERROR;
423 goto err;
426 event_add(&bufev->ev_read, NULL);
428 len = EVBUFFER_LENGTH(bufev->input);
429 if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
430 return;
432 if (bufev->readcb != NULL)
433 (*bufev->readcb)(bufev, bufev->cbarg);
434 return;
436 retry:
437 event_add(&bufev->ev_read, NULL);
438 return;
440 err:
441 (*bufev->errorcb)(bufev, what, bufev->cbarg);
444 static void
445 net_tls_writecb(int fd, short event, void *d)
447 struct bufferevent *bufev = d;
448 struct req *req = bufev->cbarg;
449 ssize_t ret;
450 size_t len;
451 short what = EVBUFFER_WRITE;
453 if (event & EV_TIMEOUT) {
454 what |= EVBUFFER_TIMEOUT;
455 goto err;
458 if (EVBUFFER_LENGTH(bufev->output) != 0) {
459 ret = tls_write(req->ctx, EVBUFFER_DATA(bufev->output),
460 EVBUFFER_LENGTH(bufev->output));
461 switch (ret) {
462 case TLS_WANT_POLLIN:
463 case TLS_WANT_POLLOUT:
464 goto retry;
465 case -1:
466 what |= EVBUFFER_ERROR;
467 goto err;
469 len = ret;
471 evbuffer_drain(bufev->output, len);
474 if (EVBUFFER_LENGTH(bufev->output) != 0)
475 event_add(&bufev->ev_write, NULL);
477 if (bufev->writecb != NULL &&
478 EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
479 (*bufev->writecb)(bufev, bufev->cbarg);
480 return;
482 retry:
483 event_add(&bufev->ev_write, NULL);
484 return;
486 err:
487 (*bufev->errorcb)(bufev, what, bufev->cbarg);
490 static int
491 gemini_parse_reply(struct req *req, const char *header, size_t len)
493 int code;
494 const char *t;
496 if (len < 4)
497 return 0;
499 if (!isdigit(header[0]) || !isdigit(header[1]))
500 return 0;
502 code = (header[0] - '0')*10 + (header[1] - '0');
503 if (header[2] != ' ')
504 return 0;
506 t = header + 3;
508 net_send_ui(IMSG_GOT_CODE, req->id, &code, sizeof(code));
509 net_send_ui(IMSG_GOT_META, req->id, t, strlen(t)+1);
511 bufferevent_disable(req->bev, EV_READ|EV_WRITE);
513 return code;
516 /* called when we're ready to read/write */
517 static void
518 net_ready(struct req *req)
520 req->bev = bufferevent_new(req->fd, net_read, net_write, net_error,
521 req);
522 if (req->bev == NULL)
523 die();
525 #if HAVE_EVENT2
526 evbuffer_unfreeze(req->bev->input, 0);
527 evbuffer_unfreeze(req->bev->output, 1);
528 #endif
530 /* setup tls i/o layer */
531 if (req->ctx != NULL) {
532 event_set(&req->bev->ev_read, req->fd, EV_READ,
533 net_tls_readcb, req->bev);
534 event_set(&req->bev->ev_write, req->fd, EV_WRITE,
535 net_tls_writecb, req->bev);
538 /* TODO: adjust watermarks */
539 bufferevent_setwatermark(req->bev, EV_WRITE, 1, 0);
540 bufferevent_setwatermark(req->bev, EV_READ, 1, 0);
542 bufferevent_enable(req->bev, EV_READ|EV_WRITE);
544 bufferevent_write(req->bev, req->req, req->len);
547 /* called after a read has been done */
548 static void
549 net_read(struct bufferevent *bev, void *d)
551 struct req *req = d;
552 struct evbuffer *src = EVBUFFER_INPUT(bev);
553 uint8_t *data;
554 size_t len, chunk;
555 int r;
556 char *header;
558 if (!req->done_header) {
559 header = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);
560 if (header == NULL && EVBUFFER_LENGTH(src) >= 1024)
561 goto err;
562 if (header == NULL)
563 return;
564 r = gemini_parse_reply(req, header, len);
565 free(header);
566 req->done_header = 1;
567 if (r == 0)
568 goto err;
569 else if (r < 20 || r >= 30)
570 close_conn(0, 0, req);
571 return;
574 if ((len = EVBUFFER_LENGTH(src)) == 0)
575 return;
576 data = EVBUFFER_DATA(src);
578 /*
579 * Split data into chunks before sending. imsg can't handle
580 * message that are "too big".
581 */
582 while (len != 0) {
583 chunk = MIN(len, 4096);
584 net_send_ui(IMSG_BUF, req->id, data, chunk);
585 data += chunk;
586 len -= chunk;
589 evbuffer_drain(src, EVBUFFER_LENGTH(src));
590 return;
592 err:
593 (*bev->errorcb)(bev, EVBUFFER_READ, bev->cbarg);
596 /* called after a write has been done */
597 static void
598 net_write(struct bufferevent *bev, void *d)
600 struct evbuffer *dst = EVBUFFER_OUTPUT(bev);
602 if (EVBUFFER_LENGTH(dst) == 0)
603 (*bev->errorcb)(bev, EVBUFFER_WRITE, bev->cbarg);
606 static void
607 net_error(struct bufferevent *bev, short error, void *d)
609 struct req *req = d;
610 struct evbuffer *src;
612 if (error & EVBUFFER_TIMEOUT) {
613 close_with_err(req, "Timeout loading page");
614 return;
617 if (error & EVBUFFER_ERROR) {
618 close_with_err(req, "buffer event error");
619 return;
622 if (error & EVBUFFER_EOF) {
623 /* EOF and no header */
624 if (!req->done_header) {
625 close_with_err(req, "protocol error");
626 return;
629 src = EVBUFFER_INPUT(req->bev);
630 if (EVBUFFER_LENGTH(src) != 0)
631 net_send_ui(IMSG_BUF, req->id, EVBUFFER_DATA(src),
632 EVBUFFER_LENGTH(src));
633 net_send_ui(IMSG_EOF, req->id, NULL, 0);
634 close_conn(0, 0, req);
635 return;
638 if (error & EVBUFFER_WRITE) {
639 /* finished sending request */
640 bufferevent_disable(bev, EV_WRITE);
641 return;
644 if (error & EVBUFFER_READ) {
645 close_with_err(req, "protocol error");
646 return;
649 close_with_errf(req, "unknown event error %x", error);
652 static void
653 handle_get_raw(struct imsg *imsg, size_t datalen)
655 struct req *req;
656 struct get_req *r;
658 r = imsg->data;
660 if (datalen != sizeof(*r))
661 die();
663 if ((req = calloc(1, sizeof(*req))) == NULL)
664 die();
666 req->id = imsg->hdr.peerid;
667 TAILQ_INSERT_HEAD(&reqhead, req, reqs);
669 strlcpy(req->url.host, r->host, sizeof(req->url.host));
670 strlcpy(req->url.port, r->port, sizeof(req->url.port));
672 strlcpy(req->req, r->req, sizeof(req->req));
673 req->len = strlen(r->req);
675 req->proto = r->proto;
677 #if HAVE_ASR_RUN
678 async_conn_towards(req);
679 #else
680 blocking_conn_towards(req);
681 #endif
684 static void
685 handle_cert_status(struct imsg *imsg, size_t datalen)
687 struct req *req;
688 int is_ok;
690 req = req_by_id(imsg->hdr.peerid);
692 if (datalen < sizeof(is_ok))
693 die();
694 memcpy(&is_ok, imsg->data, sizeof(is_ok));
696 if (is_ok)
697 net_ready(req);
698 else
699 close_conn(0, 0, req);
702 static void
703 handle_proceed(struct imsg *imsg, size_t datalen)
705 struct req *req;
707 if ((req = req_by_id(imsg->hdr.peerid)) == NULL)
708 return;
710 bufferevent_enable(req->bev, EV_READ);
713 static void
714 handle_stop(struct imsg *imsg, size_t datalen)
716 struct req *req;
718 if ((req = req_by_id(imsg->hdr.peerid)) == NULL)
719 return;
720 close_conn(0, 0, req);
723 static void
724 handle_quit(struct imsg *imsg, size_t datalen)
726 event_loopbreak();
729 static void
730 handle_dispatch_imsg(int fd, short ev, void *d)
732 struct imsgev *iev = d;
734 if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
735 err(1, "connection closed");
738 static int
739 net_send_ui(int type, uint32_t peerid, const void *data,
740 uint16_t datalen)
742 return imsg_compose_event(iev_ui, type, peerid, 0, -1,
743 data, datalen);
746 int
747 net_main(void)
749 setproctitle("net");
751 TAILQ_INIT(&reqhead);
753 event_init();
755 /* Setup pipe and event handler to the main process */
756 if ((iev_ui = malloc(sizeof(*iev_ui))) == NULL)
757 die();
758 imsg_init(&iev_ui->ibuf, 3);
759 iev_ui->handler = handle_dispatch_imsg;
760 iev_ui->events = EV_READ;
761 event_set(&iev_ui->ev, iev_ui->ibuf.fd, iev_ui->events,
762 iev_ui->handler, iev_ui);
763 event_add(&iev_ui->ev, NULL);
765 sandbox_net_process();
767 event_dispatch();
769 msgbuf_clear(&iev_ui->ibuf.w);
770 close(iev_ui->ibuf.fd);
771 free(iev_ui);
773 return 0;