aboutsummaryrefslogtreecommitdiff
path: root/networking/wget.c
blob: ee5aa63e9d6594e628ee4d5a6c2b2c66c6113761 (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
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
/* vi: set sw=4 ts=4: */
/*
 * wget - retrieve a file using HTTP or FTP
 *
 * Chip Rosenthal Covad Communications <chip@laserlink.net>
 *
 */

/* We want libc to give us xxx64 functions also */
/* http://www.unix.org/version2/whatsnew/lfs20mar.html */
#define _LARGEFILE64_SOURCE 1

#include "busybox.h"
#include <getopt.h>	/* for struct option */

struct host_info {
	// May be used if we ever will want to free() all xstrdup()s...
	/* char *allocated; */
	char *host;
	int port;
	char *path;
	int is_ftp;
	char *user;
};

static void parse_url(char *url, struct host_info *h);
static FILE *open_socket(struct sockaddr_in *s_in);
static char *gethdr(char *buf, size_t bufsiz, FILE *fp, int *istrunc);
static int ftpcmd(char *s1, char *s2, FILE *fp, char *buf);

/* Globals (can be accessed from signal handlers */
static off_t content_len;        /* Content-length of the file */
static off_t beg_range;          /* Range at which continue begins */
#if ENABLE_FEATURE_WGET_STATUSBAR
static off_t transferred;        /* Number of bytes transferred so far */
#endif
static int chunked;                     /* chunked transfer encoding */
#if ENABLE_FEATURE_WGET_STATUSBAR
static void progressmeter(int flag);
static char *curfile;                   /* Name of current file being transferred */
static struct timeval start;            /* Time a transfer started */
enum {
	STALLTIME = 5                   /* Seconds when xfer considered "stalled" */
};
#else
static void progressmeter(int flag) {}
#endif

/* Read NMEMB elements of SIZE bytes into PTR from STREAM.  Returns the
 * number of elements read, and a short count if an eof or non-interrupt
 * error is encountered.  */
static size_t safe_fread(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
	size_t ret = 0;

	do {
		clearerr(stream);
		ret += fread((char *)ptr + (ret * size), size, nmemb - ret, stream);
	} while (ret < nmemb && ferror(stream) && errno == EINTR);

	return ret;
}

/* Read a line or SIZE - 1 bytes into S, whichever is less, from STREAM.
 * Returns S, or NULL if an eof or non-interrupt error is encountered.  */
static char *safe_fgets(char *s, int size, FILE *stream)
{
	char *ret;

	do {
		clearerr(stream);
		ret = fgets(s, size, stream);
	} while (ret == NULL && ferror(stream) && errno == EINTR);

	return ret;
}

#if ENABLE_FEATURE_WGET_AUTHENTICATION
/*
 *  Base64-encode character string and return the string.
 */
static char *base64enc(unsigned char *p, char *buf, int len)
{
	bb_uuencode(p, buf, len, bb_uuenc_tbl_base64);
	return buf;
}
#endif

int wget_main(int argc, char **argv)
{
	char buf[512];
	struct host_info server, target;
	struct sockaddr_in s_in;
	int n, status;
	int port;
	int try = 5;
	unsigned opt;
	char *s;
	char *proxy = 0;
	char *dir_prefix = NULL;
#if ENABLE_FEATURE_WGET_LONG_OPTIONS
	char *extra_headers = NULL;
	llist_t *headers_llist = NULL;
#endif

	/* server.allocated = target.allocated = NULL; */

	FILE *sfp = NULL;               /* socket to web/ftp server         */
	FILE *dfp = NULL;               /* socket to ftp server (data)      */
	char *fname_out = NULL;         /* where to direct output (-O)      */
	int got_clen = 0;               /* got content-length: from server  */
	int output_fd = -1;
	int use_proxy = 1;              /* Use proxies if env vars are set  */
	const char *proxy_flag = "on";  /* Use proxies if env vars are set  */
	const char *user_agent = "Wget";/* Content of the "User-Agent" header field */

	/*
	 * Crack command line.
	 */
	enum {
		WGET_OPT_CONTINUE   = 0x1,
		WGET_OPT_QUIET      = 0x2,
		WGET_OPT_OUTNAME    = 0x4,
		WGET_OPT_PREFIX     = 0x8,
		WGET_OPT_PROXY      = 0x10,
		WGET_OPT_USER_AGENT = 0x20,
		WGET_OPT_PASSIVE    = 0x40,
		WGET_OPT_HEADER     = 0x80,
	};
#if ENABLE_FEATURE_WGET_LONG_OPTIONS
	static const struct option wget_long_options[] = {
		// name, has_arg, flag, val
		{ "continue",         no_argument, NULL, 'c' },
		{ "quiet",            no_argument, NULL, 'q' },
		{ "output-document",  required_argument, NULL, 'O' },
		{ "directory-prefix", required_argument, NULL, 'P' },
		{ "proxy",            required_argument, NULL, 'Y' },
		{ "user-agent",       required_argument, NULL, 'U' },
		{ "passive-ftp",      no_argument, NULL, 0xff },
		{ "header",           required_argument, NULL, 0xfe },
		{ 0, 0, 0, 0 }
	};
	applet_long_options = wget_long_options;
#endif
	opt_complementary = "-1" USE_FEATURE_WGET_LONG_OPTIONS(":\xfe::");
	opt = getopt32(argc, argv, "cqO:P:Y:U:",
				&fname_out, &dir_prefix,
				&proxy_flag, &user_agent
				USE_FEATURE_WGET_LONG_OPTIONS(, &headers_llist)
				);
	if (strcmp(proxy_flag, "off") == 0) {
		/* Use the proxy if necessary. */
		use_proxy = 0;
	}
#if ENABLE_FEATURE_WGET_LONG_OPTIONS
	if (headers_llist) {
		int size = 1;
		char *cp;
		llist_t *ll = headers_llist = rev_llist(headers_llist);
		while (ll) {
			size += strlen(ll->data) + 2;
			ll = ll->link;
		}
		extra_headers = cp = xmalloc(size);
		while (headers_llist) {
			cp += sprintf(cp, "%s\r\n", headers_llist->data);
			headers_llist = headers_llist->link;
		}
	}
#endif

	parse_url(argv[optind], &target);
	server.host = target.host;
	server.port = target.port;

	/*
	 * Use the proxy if necessary.
	 */
	if (use_proxy) {
		proxy = getenv(target.is_ftp ? "ftp_proxy" : "http_proxy");
		if (proxy && *proxy) {
			parse_url(proxy, &server);
		} else {
			use_proxy = 0;
		}
	}

	/* Guess an output filename */
	if (!fname_out) {
		// Dirty hack. Needed because bb_get_last_path_component
		// will destroy trailing / by storing '\0' in last byte!
		if (*target.path && target.path[strlen(target.path)-1] != '/') {
			fname_out =
#if ENABLE_FEATURE_WGET_STATUSBAR
				curfile =
#endif
				bb_get_last_path_component(target.path);
		}
		if (!fname_out || !fname_out[0]) {
			fname_out =
#if ENABLE_FEATURE_WGET_STATUSBAR
				curfile =
#endif
				"index.html";
		}
		if (dir_prefix != NULL)
			fname_out = concat_path_file(dir_prefix, fname_out);
#if ENABLE_FEATURE_WGET_STATUSBAR
	} else {
		curfile = bb_get_last_path_component(fname_out);
#endif
	}
	/* Impossible?
	if ((opt & WGET_OPT_CONTINUE) && !fname_out)
		bb_error_msg_and_die("cannot specify continue (-c) without a filename (-O)"); */

	/*
	 * Determine where to start transfer.
	 */
	if (LONE_DASH(fname_out)) {
		output_fd = 1;
		opt &= ~WGET_OPT_CONTINUE;
	}
	if (opt & WGET_OPT_CONTINUE) {
		output_fd = open(fname_out, O_WRONLY);
		if (output_fd >= 0) {
			beg_range = xlseek(output_fd, 0, SEEK_END);
		}
		/* File doesn't exist. We do not create file here yet.
		   We are not sure it exists on remove side */
	}

	/* We want to do exactly _one_ DNS lookup, since some
	 * sites (i.e. ftp.us.debian.org) use round-robin DNS
	 * and we want to connect to only one IP... */
	bb_lookup_host(&s_in, server.host);
	s_in.sin_port = server.port;
	if (!(opt & WGET_OPT_QUIET)) {
		fprintf(stderr, "Connecting to %s[%s]:%d\n",
				server.host, inet_ntoa(s_in.sin_addr), ntohs(server.port));
	}

	if (use_proxy || !target.is_ftp) {
		/*
		 *  HTTP session
		 */
		do {
			got_clen = chunked = 0;

			if (!--try)
				bb_error_msg_and_die("too many redirections");

			/*
			 * Open socket to http server
			 */
			if (sfp) fclose(sfp);
			sfp = open_socket(&s_in);

			/*
			 * Send HTTP request.
			 */
			if (use_proxy) {
				const char *format = "GET %stp://%s:%d/%s HTTP/1.1\r\n";
#if ENABLE_FEATURE_WGET_IP6_LITERAL
				if (strchr(target.host, ':'))
					format = "GET %stp://[%s]:%d/%s HTTP/1.1\r\n";
#endif
				fprintf(sfp, format,
					target.is_ftp ? "f" : "ht", target.host,
					ntohs(target.port), target.path);
			} else {
				fprintf(sfp, "GET /%s HTTP/1.1\r\n", target.path);
			}

			fprintf(sfp, "Host: %s:%u\r\nUser-Agent: %s\r\n",
				target.host, target.port, user_agent);

#if ENABLE_FEATURE_WGET_AUTHENTICATION
			if (target.user) {
				fprintf(sfp, "Authorization: Basic %s\r\n",
					base64enc((unsigned char*)target.user, buf, sizeof(buf)));
			}
			if (use_proxy && server.user) {
				fprintf(sfp, "Proxy-Authorization: Basic %s\r\n",
					base64enc((unsigned char*)server.user, buf, sizeof(buf)));
			}
#endif

			if (beg_range)
				fprintf(sfp, "Range: bytes=%"OFF_FMT"d-\r\n", beg_range);
#if ENABLE_FEATURE_WGET_LONG_OPTIONS
			if (extra_headers)
				fputs(extra_headers, sfp);
#endif
			fprintf(sfp, "Connection: close\r\n\r\n");

			/*
			* Retrieve HTTP response line and check for "200" status code.
			*/
 read_response:
			if (fgets(buf, sizeof(buf), sfp) == NULL)
				bb_error_msg_and_die("no response from server");

			s = buf;
			while (*s != '\0' && !isspace(*s)) ++s;
			s = skip_whitespace(s);
			// FIXME: no error check
			// xatou wouldn't work: "200 OK"
			status = atoi(s);
			switch (status) {
			case 0:
			case 100:
				while (gethdr(buf, sizeof(buf), sfp, &n) != NULL)
					/* eat all remaining headers */;
				goto read_response;
			case 200:
				break;
			case 300:	/* redirection */
			case 301:
			case 302:
			case 303:
				break;
			case 206:
				if (beg_range)
					break;
				/*FALLTHRU*/
			default:
				/* Show first line only and kill any ESC tricks */
				buf[strcspn(buf, "\n\r\x1b")] = '\0';
				bb_error_msg_and_die("server returned error: %s", buf);
			}

			/*
			 * Retrieve HTTP headers.
			 */
			while ((s = gethdr(buf, sizeof(buf), sfp, &n)) != NULL) {
				if (strcasecmp(buf, "content-length") == 0) {
					content_len = BB_STRTOOFF(s, NULL, 10);
					if (errno || content_len < 0) {
						bb_error_msg_and_die("content-length %s is garbage", s);
					}
					got_clen = 1;
					continue;
				}
				if (strcasecmp(buf, "transfer-encoding") == 0) {
					if (strcasecmp(s, "chunked") != 0)
						bb_error_msg_and_die("server wants to do %s transfer encoding", s);
					chunked = got_clen = 1;
				}
				if (strcasecmp(buf, "location") == 0) {
					if (s[0] == '/')
						/* free(target.allocated); */
						target.path = /* target.allocated = */ xstrdup(s+1);
					else {
						parse_url(s, &target);
						if (use_proxy == 0) {
							server.host = target.host;
							server.port = target.port;
						}
						bb_lookup_host(&s_in, server.host);
						s_in.sin_port = server.port;
						break;
					}
				}
			}
		} while (status >= 300);

		dfp = sfp;

	} else {

		/*
		 *  FTP session
		 */
		if (!target.user)
			target.user = xstrdup("anonymous:busybox@");

		sfp = open_socket(&s_in);
		if (ftpcmd(NULL, NULL, sfp, buf) != 220)
			bb_error_msg_and_die("%s", buf+4);

		/*
		 * Splitting username:password pair,
		 * trying to log in
		 */
		s = strchr(target.user, ':');
		if (s)
			*(s++) = '\0';
		switch (ftpcmd("USER ", target.user, sfp, buf)) {
		case 230:
			break;
		case 331:
			if (ftpcmd("PASS ", s, sfp, buf) == 230)
				break;
			/* FALLTHRU (failed login) */
		default:
			bb_error_msg_and_die("ftp login: %s", buf+4);
		}

		ftpcmd("TYPE I", NULL, sfp, buf);

		/*
		 * Querying file size
		 */
		if (ftpcmd("SIZE ", target.path, sfp, buf) == 213) {
			content_len = BB_STRTOOFF(buf+4, NULL, 10);
			if (errno || content_len < 0) {
				bb_error_msg_and_die("SIZE value is garbage");
			}
			got_clen = 1;
		}

		/*
		 * Entering passive mode
		 */
		if (ftpcmd("PASV", NULL, sfp, buf) != 227) {
 pasv_error:
			bb_error_msg_and_die("bad response to %s: %s", "PASV", buf);
		}
		// Response is "227 garbageN1,N2,N3,N4,P1,P2[)garbage]
		// Server's IP is N1.N2.N3.N4 (we ignore it)
		// Server's port for data connection is P1*256+P2
		s = strrchr(buf, ')');
		if (s) s[0] = '\0';
		s = strrchr(buf, ',');
		if (!s) goto pasv_error;
		port = xatou_range(s+1, 0, 255);
		*s = '\0';
		s = strrchr(buf, ',');
		if (!s) goto pasv_error;
		port += xatou_range(s+1, 0, 255) * 256;
		s_in.sin_port = htons(port);
		dfp = open_socket(&s_in);

		if (beg_range) {
			sprintf(buf, "REST %"OFF_FMT"d", beg_range);
			if (ftpcmd(buf, NULL, sfp, buf) == 350)
				content_len -= beg_range;
		}

		if (ftpcmd("RETR ", target.path, sfp, buf) > 150)
			bb_error_msg_and_die("bad response to RETR: %s", buf);
	}


	/*
	 * Retrieve file
	 */
	if (chunked) {
		fgets(buf, sizeof(buf), dfp);
		content_len = STRTOOFF(buf, NULL, 16);
		/* FIXME: error check?? */
	}

	/* Do it before progressmeter (want to have nice error message) */
	if (output_fd < 0)
		output_fd = xopen(fname_out,
			O_WRONLY|O_CREAT|O_EXCL|O_TRUNC);

	if (!(opt & WGET_OPT_QUIET))
		progressmeter(-1);

	do {
		while (content_len > 0 || !got_clen) {
			unsigned rdsz = sizeof(buf);
			if (content_len < sizeof(buf) && (chunked || got_clen))
				rdsz = (unsigned)content_len;
			n = safe_fread(buf, 1, rdsz, dfp);
			if (n <= 0)
				break;
			if (full_write(output_fd, buf, n) != n) {
				bb_perror_msg_and_die(bb_msg_write_error);
			}
#if ENABLE_FEATURE_WGET_STATUSBAR
			transferred += n;
#endif
			if (got_clen) {
				content_len -= n;
			}
		}

		if (chunked) {
			safe_fgets(buf, sizeof(buf), dfp); /* This is a newline */
			safe_fgets(buf, sizeof(buf), dfp);
			content_len = STRTOOFF(buf, NULL, 16);
			/* FIXME: error check? */
			if (content_len == 0) {
				chunked = 0; /* all done! */
			}
		}

		if (n == 0 && ferror(dfp)) {
			bb_perror_msg_and_die(bb_msg_read_error);
		}
	} while (chunked);

	if (!(opt & WGET_OPT_QUIET))
		progressmeter(1);

	if ((use_proxy == 0) && target.is_ftp) {
		fclose(dfp);
		if (ftpcmd(NULL, NULL, sfp, buf) != 226)
			bb_error_msg_and_die("ftp error: %s", buf+4);
		ftpcmd("QUIT", NULL, sfp, buf);
	}
	exit(EXIT_SUCCESS);
}


static void parse_url(char *src_url, struct host_info *h)
{
	char *url, *p, *sp;

	/* h->allocated = */ url = xstrdup(src_url);

	if (strncmp(url, "http://", 7) == 0) {
		h->port = bb_lookup_port("http", "tcp", 80);
		h->host = url + 7;
		h->is_ftp = 0;
	} else if (strncmp(url, "ftp://", 6) == 0) {
		h->port = bb_lookup_port("ftp", "tcp", 21);
		h->host = url + 6;
		h->is_ftp = 1;
	} else
		bb_error_msg_and_die("not an http or ftp url: %s", url);

	// FYI:
	// "Real" wget 'http://busybox.net?var=a/b' sends this request:
	//   'GET /?var=a/b HTTP 1.0'
	//   and saves 'index.html?var=a%2Fb' (we save 'b')
	// wget 'http://busybox.net?login=john@doe':
	//   request: 'GET /?login=john@doe HTTP/1.0'
	//   saves: 'index.html?login=john@doe' (we save '?login=john@doe')
	// wget 'http://busybox.net#test/test':
	//   request: 'GET / HTTP/1.0'
	//   saves: 'index.html' (we save 'test')
	//
	// We also don't add unique .N suffix if file exists...
	sp = strchr(h->host, '/');
	p = strchr(h->host, '?'); if (!sp || (p && sp > p)) sp = p;
	p = strchr(h->host, '#'); if (!sp || (p && sp > p)) sp = p;
	if (!sp) {
		h->path = "";
	} else if (*sp == '/') {
		*sp = '\0';
		h->path = sp + 1;
	} else { // '#' or '?'
		// http://busybox.net?login=john@doe is a valid URL
		// memmove converts to:
		// http:/busybox.nett?login=john@doe...
		memmove(h->host-1, h->host, sp - h->host);
		h->host--;
		sp[-1] = '\0';
		h->path = sp;
	}

	sp = strrchr(h->host, '@');
	h->user = NULL;
	if (sp != NULL) {
		h->user = h->host;
		*sp = '\0';
		h->host = sp + 1;
	}

	sp = h->host;

#if ENABLE_FEATURE_WGET_IP6_LITERAL
	if (sp[0] == '[') {
		char *ep;

		ep = sp + 1;
		while (*ep == ':' || isxdigit(*ep))
			ep++;
		if (*ep == ']') {
			h->host++;
			*ep = '\0';
			sp = ep + 1;
		}
	}
#endif

	p = strchr(sp, ':');
	if (p != NULL) {
		*p = '\0';
		h->port = htons(xatou16(p + 1));
	}
}


static FILE *open_socket(struct sockaddr_in *s_in)
{
	FILE *fp;

	/* glibc 2.4 seems to try seeking on it - ??! */
	/* hopefully it understands what ESPIPE means... */
	fp = fdopen(xconnect_tcp_v4(s_in), "r+");
	if (fp == NULL)
		bb_perror_msg_and_die("fdopen");

	return fp;
}


static char *gethdr(char *buf, size_t bufsiz, FILE *fp, int *istrunc)
{
	char *s, *hdrval;
	int c;

	*istrunc = 0;

	/* retrieve header line */
	if (fgets(buf, bufsiz, fp) == NULL)
		return NULL;

	/* see if we are at the end of the headers */
	for (s = buf; *s == '\r'; ++s)
		;
	if (s[0] == '\n')
		return NULL;

	/* convert the header name to lower case */
	for (s = buf; isalnum(*s) || *s == '-'; ++s)
		*s = tolower(*s);

	/* verify we are at the end of the header name */
	if (*s != ':')
		bb_error_msg_and_die("bad header line: %s", buf);

	/* locate the start of the header value */
	for (*s++ = '\0'; *s == ' ' || *s == '\t'; ++s)
		;
	hdrval = s;

	/* locate the end of header */
	while (*s != '\0' && *s != '\r' && *s != '\n')
		++s;

	/* end of header found */
	if (*s != '\0') {
		*s = '\0';
		return hdrval;
	}

	/* Rats!  The buffer isn't big enough to hold the entire header value. */
	while (c = getc(fp), c != EOF && c != '\n')
		;
	*istrunc = 1;
	return hdrval;
}

static int ftpcmd(char *s1, char *s2, FILE *fp, char *buf)
{
	int result;
	if (s1) {
		if (!s2) s2 = "";
		fprintf(fp, "%s%s\r\n", s1, s2);
		fflush(fp);
	}

	do {
		char *buf_ptr;

		if (fgets(buf, 510, fp) == NULL) {
			bb_perror_msg_and_die("error getting response");
		}
		buf_ptr = strstr(buf, "\r\n");
		if (buf_ptr) {
			*buf_ptr = '\0';
		}
	} while (!isdigit(buf[0]) || buf[3] != ' ');

	buf[3] = '\0';
	result = xatoi_u(buf);
	buf[3] = ' ';
	return result;
}

#if ENABLE_FEATURE_WGET_STATUSBAR
/* Stuff below is from BSD rcp util.c, as added to openshh.
 * Original copyright notice is retained at the end of this file.
 */
static int
getttywidth(void)
{
	int width;
	get_terminal_width_height(0, &width, NULL);
	return width;
}

static void
updateprogressmeter(int ignore)
{
	int save_errno = errno;

	progressmeter(0);
	errno = save_errno;
}

static void alarmtimer(int iwait)
{
	struct itimerval itv;

	itv.it_value.tv_sec = iwait;
	itv.it_value.tv_usec = 0;
	itv.it_interval = itv.it_value;
	setitimer(ITIMER_REAL, &itv, NULL);
}


static void
progressmeter(int flag)
{
	static struct timeval lastupdate;
	static off_t lastsize, totalsize;

	struct timeval now, td, tvwait;
	off_t abbrevsize;
	int elapsed, ratio, barlength, i;
	char buf[256];

	if (flag == -1) { /* first call to progressmeter */
		gettimeofday(&start, (struct timezone *) 0);
		lastupdate = start;
		lastsize = 0;
		totalsize = content_len + beg_range; /* as content_len changes.. */
	}

	gettimeofday(&now, (struct timezone *) 0);
	ratio = 100;
	if (totalsize != 0 && !chunked) {
		/* long long helps to have working ETA even if !LFS */
		ratio = (int) (100 * (unsigned long long)(transferred+beg_range) / totalsize);
		ratio = MIN(ratio, 100);
	}

	fprintf(stderr, "\r%-20.20s%4d%% ", curfile, ratio);

	barlength = getttywidth() - 51;
	if (barlength > 0 && barlength < sizeof(buf)) {
		i = barlength * ratio / 100;
		memset(buf, '*', i);
		memset(buf + i, ' ', barlength - i);
		buf[barlength] = '\0';
		fprintf(stderr, "|%s|", buf);
	}
	i = 0;
	abbrevsize = transferred + beg_range;
	while (abbrevsize >= 100000) {
		i++;
		abbrevsize >>= 10;
	}
	/* see http://en.wikipedia.org/wiki/Tera */
	fprintf(stderr, "%6d %c%c ", (int)abbrevsize, " KMGTPEZY"[i], i?'B':' ');

	timersub(&now, &lastupdate, &tvwait);
	if (transferred > lastsize) {
		lastupdate = now;
		lastsize = transferred;
		if (tvwait.tv_sec >= STALLTIME)
			timeradd(&start, &tvwait, &start);
		tvwait.tv_sec = 0;
	}
	timersub(&now, &start, &td);
	elapsed = td.tv_sec;

	if (tvwait.tv_sec >= STALLTIME) {
		fprintf(stderr, " - stalled -");
	} else {
		off_t to_download = totalsize - beg_range;
		if (transferred <= 0 || elapsed <= 0 || transferred > to_download || chunked) {
			fprintf(stderr, "--:--:-- ETA");
		} else {
			/* to_download / (transferred/elapsed) - elapsed: */
			int eta = (int) ((unsigned long long)to_download*elapsed/transferred - elapsed);
			/* (long long helps to have working ETA even if !LFS) */
			i = eta % 3600;
			fprintf(stderr, "%02d:%02d:%02d ETA", eta / 3600, i / 60, i % 60);
		}
	}

	if (flag == -1) { /* first call to progressmeter */
		struct sigaction sa;
		sa.sa_handler = updateprogressmeter;
		sigemptyset(&sa.sa_mask);
		sa.sa_flags = SA_RESTART;
		sigaction(SIGALRM, &sa, NULL);
		alarmtimer(1);
	} else if (flag == 1) { /* last call to progressmeter */
		alarmtimer(0);
		transferred = 0;
		putc('\n', stderr);
	}
}
#endif

/* Original copyright notice which applies to the CONFIG_FEATURE_WGET_STATUSBAR stuff,
 * much of which was blatantly stolen from openssh.  */

/*-
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
 *		ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
 *
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	$Id: wget.c,v 1.75 2004/10/08 08:27:40 andersen Exp $
 */