xref: /plan9/sys/src/cmd/hget.c (revision f9e1cf08d3be51592e03e639fc848a68dc31a55e)
1 #include <u.h>
2 #include <libc.h>
3 #include <ctype.h>
4 #include <bio.h>
5 #include <ip.h>
6 #include <libsec.h>
7 #include <auth.h>
8 
9 typedef struct URL URL;
10 struct URL
11 {
12 	int	method;
13 	char	*host;
14 	char	*port;
15 	char	*page;
16 	char	*etag;
17 	char	*redirect;
18 	char	*postbody;
19 	char	*cred;
20 	long	mtime;
21 };
22 
23 typedef struct Range Range;
24 struct Range
25 {
26 	long	start;	/* only 2 gig supported, tdb */
27 	long	end;
28 };
29 
30 typedef struct Out Out;
31 struct Out
32 {
33 	int fd;
34 	int offset;				/* notional current offset in output */
35 	int written;			/* number of bytes successfully transferred to output */
36 	DigestState *curr;		/* digest state up to offset (if known) */
37 	DigestState *hiwat;		/* digest state of all bytes written */
38 };
39 
40 enum
41 {
42 	Other,
43 	Http,
44 	Https,
45 	Ftp,
46 };
47 
48 enum
49 {
50 	Eof = 0,
51 	Error = -1,
52 	Server = -2,
53 	Changed = -3,
54 };
55 
56 int debug;
57 char *ofile;
58 
59 
60 int	doftp(URL*, URL*, Range*, Out*, long);
61 int	dohttp(URL*, URL*,  Range*, Out*, long);
62 int	crackurl(URL*, char*);
63 Range*	crackrange(char*);
64 int	getheader(int, char*, int);
65 int	httpheaders(int, int, URL*, Range*);
66 int	httprcode(int);
67 int	cistrncmp(char*, char*, int);
68 int	cistrcmp(char*, char*);
69 void	initibuf(void);
70 int	readline(int, char*, int);
71 int	readibuf(int, char*, int);
72 int	dfprint(int, char*, ...);
73 void	unreadline(char*);
74 int	output(Out*, char*, int);
75 void	setoffset(Out*, int);
76 
77 int	verbose;
78 char	*net;
79 char	tcpdir[NETPATHLEN];
80 int	headerprint;
81 
82 struct {
83 	char	*name;
84 	int	(*f)(URL*, URL*, Range*, Out*, long);
85 } method[] = {
86 	[Http]	{ "http",	dohttp },
87 	[Https]	{ "https",	dohttp },
88 	[Ftp]	{ "ftp",	doftp },
89 	[Other]	{ "_______",	nil },
90 };
91 
92 void
93 usage(void)
94 {
95 	fprint(2, "usage: %s [-dhv] [-o outfile] [-p body] [-x netmtpt] url\n", argv0);
96 	exits("usage");
97 }
98 
99 void
100 main(int argc, char **argv)
101 {
102 	URL u;
103 	Range r;
104 	int errs, n;
105 	ulong mtime;
106 	Dir *d;
107 	char postbody[4096], *p, *e, *t, *hpx;
108 	URL px; // Proxy
109 	Out out;
110 
111 	ofile = nil;
112 	p = postbody;
113 	e = p + sizeof(postbody);
114 	r.start = 0;
115 	r.end = -1;
116 	mtime = 0;
117 	memset(&u, 0, sizeof(u));
118 	memset(&px, 0, sizeof(px));
119 	hpx = getenv("httpproxy");
120 
121 	ARGBEGIN {
122 	case 'o':
123 		ofile = EARGF(usage());
124 		break;
125 	case 'd':
126 		debug = 1;
127 		break;
128 	case 'h':
129 		headerprint = 1;
130 		break;
131 	case 'v':
132 		verbose = 1;
133 		break;
134 	case 'x':
135 		net = EARGF(usage());
136 		break;
137 	case 'p':
138 		t = EARGF(usage());
139 		if(p != postbody)
140 			p = seprint(p, e, "&%s", t);
141 		else
142 			p = seprint(p, e, "%s", t);
143 		u.postbody = postbody;
144 
145 		break;
146 	default:
147 		usage();
148 	} ARGEND;
149 
150 	if(net != nil){
151 		if(strlen(net) > sizeof(tcpdir)-5)
152 			sysfatal("network mount point too long");
153 		snprint(tcpdir, sizeof(tcpdir), "%s/tcp", net);
154 	} else
155 		snprint(tcpdir, sizeof(tcpdir), "tcp");
156 
157 	if(argc != 1)
158 		usage();
159 
160 
161 	out.fd = 1;
162 	out.written = 0;
163 	out.offset = 0;
164 	out.curr = nil;
165 	out.hiwat = nil;
166 	if(ofile != nil){
167 		d = dirstat(ofile);
168 		if(d == nil){
169 			out.fd = create(ofile, OWRITE, 0664);
170 			if(out.fd < 0)
171 				sysfatal("creating %s: %r", ofile);
172 		} else {
173 			out.fd = open(ofile, OWRITE);
174 			if(out.fd < 0)
175 				sysfatal("can't open %s: %r", ofile);
176 			r.start = d->length;
177 			mtime = d->mtime;
178 			free(d);
179 		}
180 	}
181 
182 	errs = 0;
183 
184 	if(crackurl(&u, argv[0]) < 0)
185 		sysfatal("%r");
186 	if(hpx && crackurl(&px, hpx) < 0)
187 		sysfatal("%r");
188 
189 	for(;;){
190 		setoffset(&out, 0);
191 		/* transfer data */
192 		werrstr("");
193 		n = (*method[u.method].f)(&u, &px, &r, &out, mtime);
194 
195 		switch(n){
196 		case Eof:
197 			exits(0);
198 			break;
199 		case Error:
200 			if(errs++ < 10)
201 				continue;
202 			sysfatal("too many errors with no progress %r");
203 			break;
204 		case Server:
205 			sysfatal("server returned: %r");
206 			break;
207 		}
208 
209 		/* forward progress */
210 		errs = 0;
211 		r.start += n;
212 		if(r.start >= r.end)
213 			break;
214 	}
215 
216 	exits(0);
217 }
218 
219 int
220 crackurl(URL *u, char *s)
221 {
222 	char *p;
223 	int i;
224 
225 	if(u->page != nil){
226 		free(u->page);
227 		u->page = nil;
228 	}
229 
230 	/* get type */
231 	for(p = s; *p; p++){
232 		if(*p == '/'){
233 			p = s;
234 			if(u->method == Other){
235 				werrstr("missing method");
236 				return -1;
237 			}
238 			if(u->host == nil){
239 				werrstr("missing host");
240 				return -1;
241 			}
242 			u->page = strdup(p);
243 			return 0;
244 		}
245 		if(*p == ':' && *(p+1)=='/' && *(p+2)=='/'){
246 			*p = 0;
247 			p += 3;
248 			for(i = 0; i < nelem(method); i++){
249 				if(cistrcmp(s, method[i].name) == 0){
250 					u->method = i;
251 					break;
252 				}
253 			}
254 			break;
255 		}
256 	}
257 
258 	if(u->method == Other){
259 		werrstr("unsupported URL type %s", s);
260 		return -1;
261 	}
262 
263 	/* get system */
264 	free(u->host);
265 	s = p;
266 	p = strchr(s, '/');
267 	if(p == nil){
268 		u->host = strdup(s);
269 		u->page = strdup("/");
270 	} else {
271 		u->page = strdup(p);
272 		*p = 0;
273 		u->host = strdup(s);
274 		*p = '/';
275 	}
276 
277 	if(p = strchr(u->host, ':')) {
278 		*p++ = 0;
279 		u->port = p;
280 	} else
281 		u->port = method[u->method].name;
282 
283 	if(*(u->host) == 0){
284 		werrstr("bad url, null host");
285 		return -1;
286 	}
287 
288 	return 0;
289 }
290 
291 char *day[] = {
292 	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
293 };
294 
295 char *month[] = {
296 	"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
297 };
298 
299 struct
300 {
301 	int	fd;
302 	long	mtime;
303 } note;
304 
305 void
306 catch(void*, char*)
307 {
308 	Dir d;
309 
310 	nulldir(&d);
311 	d.mtime = note.mtime;
312 	if(dirfwstat(note.fd, &d) < 0)
313 		sysfatal("catch: can't dirfwstat: %r");
314 	noted(NDFLT);
315 }
316 
317 int
318 dohttp(URL *u, URL *px, Range *r, Out *out, long mtime)
319 {
320 	int fd, cfd;
321 	int redirect, auth, loop;
322 	int n, rv, code;
323 	long tot, vtime;
324 	Tm *tm;
325 	char buf[1024];
326 	char err[ERRMAX];
327 
328 
329 	/*  always move back to a previous 512 byte bound because some
330 	 *  servers can't seem to deal with requests that start at the
331 	 *  end of the file
332 	 */
333 	if(r->start)
334 		r->start = ((r->start-1)/512)*512;
335 
336 	/* loop for redirects, requires reading both response code and headers */
337 	fd = -1;
338 	for(loop = 0; loop < 32; loop++){
339 		if(px->host == nil){
340 			fd = dial(netmkaddr(u->host, tcpdir, u->port), 0, 0, 0);
341 		} else {
342 			fd = dial(netmkaddr(px->host, tcpdir, px->port), 0, 0, 0);
343 		}
344 		if(fd < 0)
345 			return Error;
346 
347 		if(u->method == Https){
348 			int tfd;
349 			TLSconn conn;
350 
351 			memset(&conn, 0, sizeof conn);
352 			tfd = tlsClient(fd, &conn);
353 			if(tfd < 0){
354 				fprint(2, "tlsClient: %r\n");
355 				close(fd);
356 				return Error;
357 			}
358 			/* BUG: check cert here? */
359 			if(conn.cert)
360 				free(conn.cert);
361 			close(fd);
362 			fd = tfd;
363 		}
364 
365 		/* write request, use range if not start of file */
366 		if(u->postbody == nil){
367 			if(px->host == nil){
368 				dfprint(fd,	"GET %s HTTP/1.0\r\n"
369 						"Host: %s\r\n"
370 						"User-agent: Plan9/hget\r\n"
371 						"Cache-Control: no-cache\r\n"
372 						"Pragma: no-cache\r\n",
373 						u->page, u->host);
374 			} else {
375 				dfprint(fd,	"GET http://%s%s HTTP/1.0\r\n"
376 						"Host: %s\r\n"
377 						"User-agent: Plan9/hget\r\n"
378 						"Cache-Control: no-cache\r\n"
379 						"Pragma: no-cache\r\n",
380 						u->host, u->page, u->host);
381 			}
382 			if(u->cred)
383 				dfprint(fd,	"Authorization: Basic %s\r\n",
384 						u->cred);
385 		} else {
386 			dfprint(fd,	"POST %s HTTP/1.0\r\n"
387 					"Host: %s\r\n"
388 					"Content-type: application/x-www-form-urlencoded\r\n"
389 					"Content-length: %d\r\n"
390 					"User-agent: Plan9/hget\r\n",
391 					u->page, u->host, strlen(u->postbody));
392 			if(u->cred)
393 				dfprint(fd, "Authorization: Basic %s\r\n", u->cred);
394 		}
395 		if(r->start != 0){
396 			dfprint(fd, "Range: bytes=%d-\n", r->start);
397 			if(u->etag != nil){
398 				dfprint(fd, "If-range: %s\n", u->etag);
399 			} else {
400 				tm = gmtime(mtime);
401 				dfprint(fd, "If-range: %s, %d %s %d %2d:%2.2d:%2.2d GMT\n",
402 					day[tm->wday], tm->mday, month[tm->mon],
403 					tm->year+1900, tm->hour, tm->min, tm->sec);
404 			}
405 		}
406 		if((cfd = open("/mnt/webcookies/http", ORDWR)) >= 0){
407 			if(fprint(cfd, "http://%s%s", u->host, u->page) > 0){
408 				while((n = read(cfd, buf, sizeof buf)) > 0){
409 					if(debug)
410 						write(2, buf, n);
411 					write(fd, buf, n);
412 				}
413 			}else{
414 				close(cfd);
415 				cfd = -1;
416 			}
417 		}
418 
419 		dfprint(fd, "\r\n", u->host);
420 		if(u->postbody)
421 			dfprint(fd,	"%s", u->postbody);
422 
423 		auth = 0;
424 		redirect = 0;
425 		initibuf();
426 		code = httprcode(fd);
427 		switch(code){
428 		case Error:	/* connection timed out */
429 		case Eof:
430 			close(fd);
431 			close(cfd);
432 			return code;
433 
434 		case 200:	/* OK */
435 		case 201:	/* Created */
436 		case 202:	/* Accepted */
437 			if(ofile == nil && r->start != 0)
438 				sysfatal("page changed underfoot");
439 			break;
440 
441 		case 204:	/* No Content */
442 			sysfatal("No Content");
443 
444 		case 206:	/* Partial Content */
445 			setoffset(out, r->start);
446 			break;
447 
448 		case 301:	/* Moved Permanently */
449 		case 302:	/* Moved Temporarily */
450 			redirect = 1;
451 			u->postbody = nil;
452 			break;
453 
454 		case 304:	/* Not Modified */
455 			break;
456 
457 		case 400:	/* Bad Request */
458 			sysfatal("Bad Request");
459 
460 		case 401:	/* Unauthorized */
461 			if (auth)
462 				sysfatal("Authentication failed");
463 			auth = 1;
464 			break;
465 
466 		case 402:	/* ??? */
467 			sysfatal("Unauthorized");
468 
469 		case 403:	/* Forbidden */
470 			sysfatal("Forbidden by server");
471 
472 		case 404:	/* Not Found */
473 			sysfatal("Not found on server");
474 
475 		case 407:	/* Proxy Authentication */
476 			sysfatal("Proxy authentication required");
477 
478 		case 500:	/* Internal server error */
479 			sysfatal("Server choked");
480 
481 		case 501:	/* Not implemented */
482 			sysfatal("Server can't do it!");
483 
484 		case 502:	/* Bad gateway */
485 			sysfatal("Bad gateway");
486 
487 		case 503:	/* Service unavailable */
488 			sysfatal("Service unavailable");
489 
490 		default:
491 			sysfatal("Unknown response code %d", code);
492 		}
493 
494 		if(u->redirect != nil){
495 			free(u->redirect);
496 			u->redirect = nil;
497 		}
498 
499 		rv = httpheaders(fd, cfd, u, r);
500 		close(cfd);
501 		if(rv != 0){
502 			close(fd);
503 			return rv;
504 		}
505 
506 		if(!redirect && !auth)
507 			break;
508 
509 		if (redirect){
510 			if(u->redirect == nil)
511 				sysfatal("redirect: no URL");
512 			if(crackurl(u, u->redirect) < 0)
513 				sysfatal("redirect: %r");
514 		}
515 	}
516 
517 	/* transfer whatever you get */
518 	if(ofile != nil && u->mtime != 0){
519 		note.fd = out->fd;
520 		note.mtime = u->mtime;
521 		notify(catch);
522 	}
523 
524 	tot = 0;
525 	vtime = 0;
526 	for(;;){
527 		n = readibuf(fd, buf, sizeof(buf));
528 		if(n <= 0)
529 			break;
530 		if(output(out, buf, n) != n)
531 			break;
532 		tot += n;
533 		if(verbose && (vtime != time(0) || r->start == r->end)) {
534 			vtime = time(0);
535 			fprint(2, "%ld %ld\n", r->start+tot, r->end);
536 		}
537 	}
538 	notify(nil);
539 	close(fd);
540 
541 	if(ofile != nil && u->mtime != 0){
542 		Dir d;
543 
544 		rerrstr(err, sizeof err);
545 		nulldir(&d);
546 		d.mtime = u->mtime;
547 		if(dirfwstat(out->fd, &d) < 0)
548 			fprint(2, "couldn't set mtime: %r\n");
549 		errstr(err, sizeof err);
550 	}
551 
552 	return tot;
553 }
554 
555 /* get the http response code */
556 int
557 httprcode(int fd)
558 {
559 	int n;
560 	char *p;
561 	char buf[256];
562 
563 	n = readline(fd, buf, sizeof(buf)-1);
564 	if(n <= 0)
565 		return n;
566 	if(debug)
567 		fprint(2, "%d <- %s\n", fd, buf);
568 	p = strchr(buf, ' ');
569 	if(strncmp(buf, "HTTP/", 5) != 0 || p == nil){
570 		werrstr("bad response from server");
571 		return -1;
572 	}
573 	buf[n] = 0;
574 	return atoi(p+1);
575 }
576 
577 /* read in and crack the http headers, update u and r */
578 void	hhetag(char*, URL*, Range*);
579 void	hhmtime(char*, URL*, Range*);
580 void	hhclen(char*, URL*, Range*);
581 void	hhcrange(char*, URL*, Range*);
582 void	hhuri(char*, URL*, Range*);
583 void	hhlocation(char*, URL*, Range*);
584 void	hhauth(char*, URL*, Range*);
585 
586 struct {
587 	char *name;
588 	void (*f)(char*, URL*, Range*);
589 } headers[] = {
590 	{ "etag:", hhetag },
591 	{ "last-modified:", hhmtime },
592 	{ "content-length:", hhclen },
593 	{ "content-range:", hhcrange },
594 	{ "uri:", hhuri },
595 	{ "location:", hhlocation },
596 	{ "WWW-Authenticate:", hhauth },
597 };
598 int
599 httpheaders(int fd, int cfd, URL *u, Range *r)
600 {
601 	char buf[2048];
602 	char *p;
603 	int i, n;
604 
605 	for(;;){
606 		n = getheader(fd, buf, sizeof(buf));
607 		if(n <= 0)
608 			break;
609 		if(cfd >= 0)
610 			fprint(cfd, "%s\n", buf);
611 		for(i = 0; i < nelem(headers); i++){
612 			n = strlen(headers[i].name);
613 			if(cistrncmp(buf, headers[i].name, n) == 0){
614 				/* skip field name and leading white */
615 				p = buf + n;
616 				while(*p == ' ' || *p == '\t')
617 					p++;
618 
619 				(*headers[i].f)(p, u, r);
620 				break;
621 			}
622 		}
623 	}
624 	return n;
625 }
626 
627 /*
628  *  read a single mime header, collect continuations.
629  *
630  *  this routine assumes that there is a blank line twixt
631  *  the header and the message body, otherwise bytes will
632  *  be lost.
633  */
634 int
635 getheader(int fd, char *buf, int n)
636 {
637 	char *p, *e;
638 	int i;
639 
640 	n--;
641 	p = buf;
642 	for(e = p + n; ; p += i){
643 		i = readline(fd, p, e-p);
644 		if(i < 0)
645 			return i;
646 
647 		if(p == buf){
648 			/* first line */
649 			if(strchr(buf, ':') == nil)
650 				break;		/* end of headers */
651 		} else {
652 			/* continuation line */
653 			if(*p != ' ' && *p != '\t'){
654 				unreadline(p);
655 				*p = 0;
656 				break;		/* end of this header */
657 			}
658 		}
659 	}
660 	if(headerprint)
661 		print("%s\n", buf);
662 
663 	if(debug)
664 		fprint(2, "%d <- %s\n", fd, buf);
665 	return p-buf;
666 }
667 
668 void
669 hhetag(char *p, URL *u, Range*)
670 {
671 	if(u->etag != nil){
672 		if(strcmp(u->etag, p) != 0)
673 			sysfatal("file changed underfoot");
674 	} else
675 		u->etag = strdup(p);
676 }
677 
678 char*	monthchars = "janfebmaraprmayjunjulaugsepoctnovdec";
679 
680 void
681 hhmtime(char *p, URL *u, Range*)
682 {
683 	char *month, *day, *yr, *hms;
684 	char *fields[6];
685 	Tm tm, now;
686 	int i;
687 
688 	i = getfields(p, fields, 6, 1, " \t");
689 	if(i < 5)
690 		return;
691 
692 	day = fields[1];
693 	month = fields[2];
694 	yr = fields[3];
695 	hms = fields[4];
696 
697 	/* default time */
698 	now = *gmtime(time(0));
699 	tm = now;
700 	tm.yday = 0;
701 
702 	/* convert ascii month to a number twixt 1 and 12 */
703 	if(*month >= '0' && *month <= '9'){
704 		tm.mon = atoi(month) - 1;
705 		if(tm.mon < 0 || tm.mon > 11)
706 			tm.mon = 5;
707 	} else {
708 		for(p = month; *p; p++)
709 			*p = tolower(*p);
710 		for(i = 0; i < 12; i++)
711 			if(strncmp(&monthchars[i*3], month, 3) == 0){
712 				tm.mon = i;
713 				break;
714 			}
715 	}
716 
717 	tm.mday = atoi(day);
718 
719 	if(hms) {
720 		tm.hour = strtoul(hms, &p, 10);
721 		if(*p == ':') {
722 			p++;
723 			tm.min = strtoul(p, &p, 10);
724 			if(*p == ':') {
725 				p++;
726 				tm.sec = strtoul(p, &p, 10);
727 			}
728 		}
729 		if(tolower(*p) == 'p')
730 			tm.hour += 12;
731 	}
732 
733 	if(yr) {
734 		tm.year = atoi(yr);
735 		if(tm.year >= 1900)
736 			tm.year -= 1900;
737 	} else {
738 		if(tm.mon > now.mon || (tm.mon == now.mon && tm.mday > now.mday+1))
739 			tm.year--;
740 	}
741 
742 	strcpy(tm.zone, "GMT");
743 	/* convert to epoch seconds */
744 	u->mtime = tm2sec(&tm);
745 }
746 
747 void
748 hhclen(char *p, URL*, Range *r)
749 {
750 	r->end = atoi(p);
751 }
752 
753 void
754 hhcrange(char *p, URL*, Range *r)
755 {
756 	char *x;
757 	vlong l;
758 
759 	l = 0;
760 	x = strchr(p, '/');
761 	if(x)
762 		l = atoll(x+1);
763 	if(l == 0) {
764 		x = strchr(p, '-');
765 		if(x)
766 			l = atoll(x+1);
767 	}
768 	if(l)
769 		r->end = l;
770 }
771 
772 void
773 hhuri(char *p, URL *u, Range*)
774 {
775 	if(*p != '<')
776 		return;
777 	u->redirect = strdup(p+1);
778 	p = strchr(u->redirect, '>');
779 	if(p != nil)
780 		*p = 0;
781 }
782 
783 void
784 hhlocation(char *p, URL *u, Range*)
785 {
786 	u->redirect = strdup(p);
787 }
788 
789 void
790 hhauth(char *p, URL *u, Range*)
791 {
792 	char *f[4];
793 	UserPasswd *up;
794 	char *s, cred[64];
795 
796 	if (cistrncmp(p, "basic ", 6) != 0)
797 		sysfatal("only Basic authentication supported");
798 
799 	if (gettokens(p, f, nelem(f), "\"") < 2)
800 		sysfatal("garbled auth data");
801 
802 	if ((up = auth_getuserpasswd(auth_getkey, "proto=pass service=http server=%q realm=%q",
803 	    	u->host, f[1])) == nil)
804 			sysfatal("cannot authenticate");
805 
806 	s = smprint("%s:%s", up->user, up->passwd);
807 	if(enc64(cred, sizeof(cred), (uchar *)s, strlen(s)) == -1)
808 		sysfatal("enc64");
809   		free(s);
810 
811 	assert(u->cred = strdup(cred));
812 }
813 
814 enum
815 {
816 	/* ftp return codes */
817 	Extra=		1,
818 	Success=	2,
819 	Incomplete=	3,
820 	TempFail=	4,
821 	PermFail=	5,
822 
823 	Nnetdir=	64,	/* max length of network directory paths */
824 	Ndialstr=	64,		/* max length of dial strings */
825 };
826 
827 int ftpcmd(int, char*, ...);
828 int ftprcode(int, char*, int);
829 int hello(int);
830 int logon(int);
831 int xfertype(int, char*);
832 int passive(int, URL*);
833 int active(int, URL*);
834 int ftpxfer(int, Out*, Range*);
835 int terminateftp(int, int);
836 int getaddrport(char*, uchar*, uchar*);
837 int ftprestart(int, Out*, URL*, Range*, long);
838 
839 int
840 doftp(URL *u, URL *px, Range *r, Out *out, long mtime)
841 {
842 	int pid, ctl, data, rv;
843 	Waitmsg *w;
844 	char msg[64];
845 	char conndir[NETPATHLEN];
846 	char *p;
847 
848 	/* untested, proxy doesn't work with ftp (I think) */
849 	if(px->host == nil){
850 		ctl = dial(netmkaddr(u->host, tcpdir, u->port), 0, conndir, 0);
851 	} else {
852 		ctl = dial(netmkaddr(px->host, tcpdir, px->port), 0, conndir, 0);
853 	}
854 
855 	if(ctl < 0)
856 		return Error;
857 	if(net == nil){
858 		p = strrchr(conndir, '/');
859 		*p = 0;
860 		snprint(tcpdir, sizeof(tcpdir), conndir);
861 	}
862 
863 	initibuf();
864 
865 	rv = hello(ctl);
866 	if(rv < 0)
867 		return terminateftp(ctl, rv);
868 
869 	rv = logon(ctl);
870 	if(rv < 0)
871 		return terminateftp(ctl, rv);
872 
873 	rv = xfertype(ctl, "I");
874 	if(rv < 0)
875 		return terminateftp(ctl, rv);
876 
877 	/* if file is up to date and the right size, stop */
878 	if(ftprestart(ctl, out, u, r, mtime) > 0){
879 		close(ctl);
880 		return Eof;
881 	}
882 
883 	/* first try passive mode, then active */
884 	data = passive(ctl, u);
885 	if(data < 0){
886 		data = active(ctl, u);
887 		if(data < 0)
888 			return Error;
889 	}
890 
891 	/* fork */
892 	switch(pid = rfork(RFPROC|RFFDG|RFMEM)){
893 	case -1:
894 		close(data);
895 		return terminateftp(ctl, Error);
896 	case 0:
897 		ftpxfer(data, out, r);
898 		close(data);
899 		_exits(0);
900 	default:
901 		close(data);
902 		break;
903 	}
904 
905 	/* wait for reply message */
906 	rv = ftprcode(ctl, msg, sizeof(msg));
907 	close(ctl);
908 
909 	/* wait for process to terminate */
910 	w = nil;
911 	for(;;){
912 		free(w);
913 		w = wait();
914 		if(w == nil)
915 			return Error;
916 		if(w->pid == pid){
917 			if(w->msg[0] == 0){
918 				free(w);
919 				break;
920 			}
921 			werrstr("xfer: %s", w->msg);
922 			free(w);
923 			return Error;
924 		}
925 	}
926 
927 	switch(rv){
928 	case Success:
929 		return Eof;
930 	case TempFail:
931 		return Server;
932 	default:
933 		return Error;
934 	}
935 }
936 
937 int
938 ftpcmd(int ctl, char *fmt, ...)
939 {
940 	va_list arg;
941 	char buf[2*1024], *s;
942 
943 	va_start(arg, fmt);
944 	s = vseprint(buf, buf + (sizeof(buf)-4) / sizeof(*buf), fmt, arg);
945 	va_end(arg);
946 	if(debug)
947 		fprint(2, "%d -> %s\n", ctl, buf);
948 	*s++ = '\r';
949 	*s++ = '\n';
950 	if(write(ctl, buf, s - buf) != s - buf)
951 		return -1;
952 	return 0;
953 }
954 
955 int
956 ftprcode(int ctl, char *msg, int len)
957 {
958 	int rv;
959 	int i;
960 	char *p;
961 
962 	len--;	/* room for terminating null */
963 	for(;;){
964 		*msg = 0;
965 		i = readline(ctl, msg, len);
966 		if(i < 0)
967 			break;
968 		if(debug)
969 			fprint(2, "%d <- %s\n", ctl, msg);
970 
971 		/* stop if not a continuation */
972 		rv = strtol(msg, &p, 10);
973 		if(rv >= 100 && rv < 600 && p==msg+3 && *p == ' ')
974 			return rv/100;
975 	}
976 	*msg = 0;
977 
978 	return -1;
979 }
980 
981 int
982 hello(int ctl)
983 {
984 	char msg[1024];
985 
986 	/* wait for hello from other side */
987 	if(ftprcode(ctl, msg, sizeof(msg)) != Success){
988 		werrstr("HELLO: %s", msg);
989 		return Server;
990 	}
991 	return 0;
992 }
993 
994 int
995 getdec(char *p, int n)
996 {
997 	int x = 0;
998 	int i;
999 
1000 	for(i = 0; i < n; i++)
1001 		x = x*10 + (*p++ - '0');
1002 	return x;
1003 }
1004 
1005 int
1006 ftprestart(int ctl, Out *out, URL *u, Range *r, long mtime)
1007 {
1008 	Tm tm;
1009 	char msg[1024];
1010 	long x, rmtime;
1011 
1012 	ftpcmd(ctl, "MDTM %s", u->page);
1013 	if(ftprcode(ctl, msg, sizeof(msg)) != Success){
1014 		r->start = 0;
1015 		return 0;		/* need to do something */
1016 	}
1017 
1018 	/* decode modification time */
1019 	if(strlen(msg) < 4 + 4 + 2 + 2 + 2 + 2 + 2){
1020 		r->start = 0;
1021 		return 0;		/* need to do something */
1022 	}
1023 	memset(&tm, 0, sizeof(tm));
1024 	tm.year = getdec(msg+4, 4) - 1900;
1025 	tm.mon = getdec(msg+4+4, 2) - 1;
1026 	tm.mday = getdec(msg+4+4+2, 2);
1027 	tm.hour = getdec(msg+4+4+2+2, 2);
1028 	tm.min = getdec(msg+4+4+2+2+2, 2);
1029 	tm.sec = getdec(msg+4+4+2+2+2+2, 2);
1030 	strcpy(tm.zone, "GMT");
1031 	rmtime = tm2sec(&tm);
1032 	if(rmtime > mtime)
1033 		r->start = 0;
1034 
1035 	/* get size */
1036 	ftpcmd(ctl, "SIZE %s", u->page);
1037 	if(ftprcode(ctl, msg, sizeof(msg)) == Success){
1038 		x = atol(msg+4);
1039 		if(r->start == x)
1040 			return 1;	/* we're up to date */
1041 		r->end = x;
1042 	}
1043 
1044 	/* seek to restart point */
1045 	if(r->start > 0){
1046 		ftpcmd(ctl, "REST %lud", r->start);
1047 		if(ftprcode(ctl, msg, sizeof(msg)) == Incomplete){
1048 			setoffset(out, r->start);
1049 		}else
1050 			r->start = 0;
1051 	}
1052 
1053 	return 0;	/* need to do something */
1054 }
1055 
1056 int
1057 logon(int ctl)
1058 {
1059 	char msg[1024];
1060 
1061 	/* login anonymous */
1062 	ftpcmd(ctl, "USER anonymous");
1063 	switch(ftprcode(ctl, msg, sizeof(msg))){
1064 	case Success:
1065 		return 0;
1066 	case Incomplete:
1067 		break;	/* need password */
1068 	default:
1069 		werrstr("USER: %s", msg);
1070 		return Server;
1071 	}
1072 
1073 	/* send user id as password */
1074 	sprint(msg, "%s@closedmind.org", getuser());
1075 	ftpcmd(ctl, "PASS %s", msg);
1076 	if(ftprcode(ctl, msg, sizeof(msg)) != Success){
1077 		werrstr("PASS: %s", msg);
1078 		return Server;
1079 	}
1080 
1081 	return 0;
1082 }
1083 
1084 int
1085 xfertype(int ctl, char *t)
1086 {
1087 	char msg[1024];
1088 
1089 	ftpcmd(ctl, "TYPE %s", t);
1090 	if(ftprcode(ctl, msg, sizeof(msg)) != Success){
1091 		werrstr("TYPE %s: %s", t, msg);
1092 		return Server;
1093 	}
1094 
1095 	return 0;
1096 }
1097 
1098 int
1099 passive(int ctl, URL *u)
1100 {
1101 	char msg[1024];
1102 	char ipaddr[32];
1103 	char *f[6];
1104 	char *p;
1105 	int fd;
1106 	int port;
1107 	char aport[12];
1108 
1109 	ftpcmd(ctl, "PASV");
1110 	if(ftprcode(ctl, msg, sizeof(msg)) != Success)
1111 		return Error;
1112 
1113 	/* get address and port number from reply, this is AI */
1114 	p = strchr(msg, '(');
1115 	if(p == nil){
1116 		for(p = msg+3; *p; p++)
1117 			if(isdigit(*p))
1118 				break;
1119 	} else
1120 		p++;
1121 	if(getfields(p, f, 6, 0, ",)") < 6){
1122 		werrstr("ftp protocol botch");
1123 		return Server;
1124 	}
1125 	snprint(ipaddr, sizeof(ipaddr), "%s.%s.%s.%s",
1126 		f[0], f[1], f[2], f[3]);
1127 	port = ((atoi(f[4])&0xff)<<8) + (atoi(f[5])&0xff);
1128 	sprint(aport, "%d", port);
1129 
1130 	/* open data connection */
1131 	fd = dial(netmkaddr(ipaddr, tcpdir, aport), 0, 0, 0);
1132 	if(fd < 0){
1133 		werrstr("passive mode failed: %r");
1134 		return Error;
1135 	}
1136 
1137 	/* tell remote to send a file */
1138 	ftpcmd(ctl, "RETR %s", u->page);
1139 	if(ftprcode(ctl, msg, sizeof(msg)) != Extra){
1140 		werrstr("RETR %s: %s", u->page, msg);
1141 		return Error;
1142 	}
1143 	return fd;
1144 }
1145 
1146 int
1147 active(int ctl, URL *u)
1148 {
1149 	char msg[1024];
1150 	char dir[40], ldir[40];
1151 	uchar ipaddr[4];
1152 	uchar port[2];
1153 	int lcfd, dfd, afd;
1154 
1155 	/* announce a port for the call back */
1156 	snprint(msg, sizeof(msg), "%s!*!0", tcpdir);
1157 	afd = announce(msg, dir);
1158 	if(afd < 0)
1159 		return Error;
1160 
1161 	/* get a local address/port of the annoucement */
1162 	if(getaddrport(dir, ipaddr, port) < 0){
1163 		close(afd);
1164 		return Error;
1165 	}
1166 
1167 	/* tell remote side address and port*/
1168 	ftpcmd(ctl, "PORT %d,%d,%d,%d,%d,%d", ipaddr[0], ipaddr[1], ipaddr[2],
1169 		ipaddr[3], port[0], port[1]);
1170 	if(ftprcode(ctl, msg, sizeof(msg)) != Success){
1171 		close(afd);
1172 		werrstr("active: %s", msg);
1173 		return Error;
1174 	}
1175 
1176 	/* tell remote to send a file */
1177 	ftpcmd(ctl, "RETR %s", u->page);
1178 	if(ftprcode(ctl, msg, sizeof(msg)) != Extra){
1179 		close(afd);
1180 		werrstr("RETR: %s", msg);
1181 		return Server;
1182 	}
1183 
1184 	/* wait for a connection */
1185 	lcfd = listen(dir, ldir);
1186 	if(lcfd < 0){
1187 		close(afd);
1188 		return Error;
1189 	}
1190 	dfd = accept(lcfd, ldir);
1191 	if(dfd < 0){
1192 		close(afd);
1193 		close(lcfd);
1194 		return Error;
1195 	}
1196 	close(afd);
1197 	close(lcfd);
1198 
1199 	return dfd;
1200 }
1201 
1202 int
1203 ftpxfer(int in, Out *out, Range *r)
1204 {
1205 	char buf[1024];
1206 	long vtime;
1207 	int i, n;
1208 
1209 	vtime = 0;
1210 	for(n = 0;;n += i){
1211 		i = read(in, buf, sizeof(buf));
1212 		if(i == 0)
1213 			break;
1214 		if(i < 0)
1215 			return Error;
1216 		if(output(out, buf, i) != i)
1217 			return Error;
1218 		r->start += i;
1219 		if(verbose && (vtime != time(0) || r->start == r->end)) {
1220 			vtime = time(0);
1221 			fprint(2, "%ld %ld\n", r->start, r->end);
1222 		}
1223 	}
1224 	return n;
1225 }
1226 
1227 int
1228 terminateftp(int ctl, int rv)
1229 {
1230 	close(ctl);
1231 	return rv;
1232 }
1233 
1234 /*
1235  * case insensitive strcmp (why aren't these in libc?)
1236  */
1237 int
1238 cistrncmp(char *a, char *b, int n)
1239 {
1240 	while(n-- > 0){
1241 		if(tolower(*a++) != tolower(*b++))
1242 			return -1;
1243 	}
1244 	return 0;
1245 }
1246 
1247 int
1248 cistrcmp(char *a, char *b)
1249 {
1250 	while(*a || *b)
1251 		if(tolower(*a++) != tolower(*b++))
1252 			return -1;
1253 
1254 	return 0;
1255 }
1256 
1257 /*
1258  *  buffered io
1259  */
1260 struct
1261 {
1262 	char *rp;
1263 	char *wp;
1264 	char buf[4*1024];
1265 } b;
1266 
1267 void
1268 initibuf(void)
1269 {
1270 	b.rp = b.wp = b.buf;
1271 }
1272 
1273 /*
1274  *  read a possibly buffered line, strip off trailing while
1275  */
1276 int
1277 readline(int fd, char *buf, int len)
1278 {
1279 	int n;
1280 	char *p;
1281 	int eof = 0;
1282 
1283 	len--;
1284 
1285 	for(p = buf;;){
1286 		if(b.rp >= b.wp){
1287 			n = read(fd, b.wp, sizeof(b.buf)/2);
1288 			if(n < 0)
1289 				return -1;
1290 			if(n == 0){
1291 				eof = 1;
1292 				break;
1293 			}
1294 			b.wp += n;
1295 		}
1296 		n = *b.rp++;
1297 		if(len > 0){
1298 			*p++ = n;
1299 			len--;
1300 		}
1301 		if(n == '\n')
1302 			break;
1303 	}
1304 
1305 	/* drop trailing white */
1306 	for(;;){
1307 		if(p <= buf)
1308 			break;
1309 		n = *(p-1);
1310 		if(n != ' ' && n != '\t' && n != '\r' && n != '\n')
1311 			break;
1312 		p--;
1313 	}
1314 	*p = 0;
1315 
1316 	if(eof && p == buf)
1317 		return -1;
1318 
1319 	return p-buf;
1320 }
1321 
1322 void
1323 unreadline(char *line)
1324 {
1325 	int i, n;
1326 
1327 	i = strlen(line);
1328 	n = b.wp-b.rp;
1329 	memmove(&b.buf[i+1], b.rp, n);
1330 	memmove(b.buf, line, i);
1331 	b.buf[i] = '\n';
1332 	b.rp = b.buf;
1333 	b.wp = b.rp + i + 1 + n;
1334 }
1335 
1336 int
1337 readibuf(int fd, char *buf, int len)
1338 {
1339 	int n;
1340 
1341 	n = b.wp-b.rp;
1342 	if(n > 0){
1343 		if(n > len)
1344 			n = len;
1345 		memmove(buf, b.rp, n);
1346 		b.rp += n;
1347 		return n;
1348 	}
1349 	return read(fd, buf, len);
1350 }
1351 
1352 int
1353 dfprint(int fd, char *fmt, ...)
1354 {
1355 	char buf[4*1024];
1356 	va_list arg;
1357 
1358 	va_start(arg, fmt);
1359 	vseprint(buf, buf+sizeof(buf), fmt, arg);
1360 	va_end(arg);
1361 	if(debug)
1362 		fprint(2, "%d -> %s", fd, buf);
1363 	return fprint(fd, "%s", buf);
1364 }
1365 
1366 int
1367 getaddrport(char *dir, uchar *ipaddr, uchar *port)
1368 {
1369 	char buf[256];
1370 	int fd, i;
1371 	char *p;
1372 
1373 	snprint(buf, sizeof(buf), "%s/local", dir);
1374 	fd = open(buf, OREAD);
1375 	if(fd < 0)
1376 		return -1;
1377 	i = read(fd, buf, sizeof(buf)-1);
1378 	close(fd);
1379 	if(i <= 0)
1380 		return -1;
1381 	buf[i] = 0;
1382 	p = strchr(buf, '!');
1383 	if(p != nil)
1384 		*p++ = 0;
1385 	v4parseip(ipaddr, buf);
1386 	i = atoi(p);
1387 	port[0] = i>>8;
1388 	port[1] = i;
1389 	return 0;
1390 }
1391 
1392 void
1393 md5free(DigestState *state)
1394 {
1395 	uchar x[MD5dlen];
1396 	md5(nil, 0, x, state);
1397 }
1398 
1399 DigestState*
1400 md5dup(DigestState *state)
1401 {
1402 	char *p;
1403 
1404 	p = md5pickle(state);
1405 	if(p == nil)
1406 		sysfatal("md5pickle: %r");
1407 	state = md5unpickle(p);
1408 	if(state == nil)
1409 		sysfatal("md5unpickle: %r");
1410 	free(p);
1411 	return state;
1412 }
1413 
1414 void
1415 setoffset(Out *out, int offset)
1416 {
1417 	md5free(out->curr);
1418 	if(offset == 0)
1419 		out->curr = md5(nil, 0, nil, nil);
1420 	else
1421 		out->curr = nil;
1422 	out->offset = offset;
1423 	out->written = offset;
1424 	if(ofile != nil)
1425 		if(seek(out->fd, offset, 0) != offset)
1426 			sysfatal("seek: %r");
1427 }
1428 
1429 /*
1430  * write some output, discarding it (but keeping track)
1431  * if we've already written it. if we've gone backwards,
1432  * verify that everything previously written matches
1433  * that which would have been written from the current
1434  * output.
1435  */
1436 int
1437 output(Out *out, char *buf, int nb)
1438 {
1439 	int n, d;
1440 	uchar m0[MD5dlen], m1[MD5dlen];
1441 
1442 	n = nb;
1443 	d = out->written - out->offset;
1444 	assert(d >= 0);
1445 	if(d > 0){
1446 		if(n < d){
1447 			if(out->curr != nil)
1448 				md5((uchar*)buf, n, nil, out->curr);
1449 			out->offset += n;
1450 			return n;
1451 		}
1452 		if(out->curr != nil){
1453 			md5((uchar*)buf, d, m0, out->curr);
1454 			out->curr = nil;
1455 			md5(nil, 0, m1, md5dup(out->hiwat));
1456 			if(memcmp(m0, m1, MD5dlen) != 0){
1457 				fprint(2, "integrity check failure at offset %d\n", out->written);
1458 				return -1;
1459 			}
1460 		}
1461 		buf += d;
1462 		n -= d;
1463 		out->offset += d;
1464 	}
1465 	if(n > 0){
1466 		out->hiwat = md5((uchar*)buf, n, nil, out->hiwat);
1467 		n = write(out->fd, buf, n);
1468 		if(n > 0){
1469 			out->offset += n;
1470 			out->written += n;
1471 		}
1472 	}
1473 	return n + d;
1474 }
1475 
1476