http.c revision 63716 
1/*-
2 * Copyright (c) 2000 Dag-Erling Co�dan Sm�rgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 *      $FreeBSD: head/lib/libfetch/http.c 63716 2000-07-21 11:02:43Z des $
29 */
30
31/*
32 * The following copyright applies to the base64 code:
33 *
34 *-
35 * Copyright 1997 Massachusetts Institute of Technology
36 *
37 * Permission to use, copy, modify, and distribute this software and
38 * its documentation for any purpose and without fee is hereby
39 * granted, provided that both the above copyright notice and this
40 * permission notice appear in all copies, that both the above
41 * copyright notice and this permission notice appear in all
42 * supporting documentation, and that the name of M.I.T. not be used
43 * in advertising or publicity pertaining to distribution of the
44 * software without specific, written prior permission.  M.I.T. makes
45 * no representations about the suitability of this software for any
46 * purpose.  It is provided "as is" without express or implied
47 * warranty.
48 *
49 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
50 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
51 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
52 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
53 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
54 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
55 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
56 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
57 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
58 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
59 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 */
62
63#include <sys/param.h>
64#include <sys/socket.h>
65
66#include <ctype.h>
67#include <err.h>
68#include <errno.h>
69#include <locale.h>
70#include <netdb.h>
71#include <stdarg.h>
72#include <stdio.h>
73#include <stdlib.h>
74#include <string.h>
75#include <time.h>
76#include <unistd.h>
77
78#include "fetch.h"
79#include "common.h"
80#include "httperr.h"
81
82extern char *__progname; /* XXX not portable */
83
84/* Maximum number of redirects to follow */
85#define MAX_REDIRECT 5
86
87/* Symbolic names for reply codes we care about */
88#define HTTP_OK			200
89#define HTTP_PARTIAL		206
90#define HTTP_MOVED_PERM		301
91#define HTTP_MOVED_TEMP		302
92#define HTTP_SEE_OTHER		303
93#define HTTP_NEED_AUTH		401
94#define HTTP_NEED_PROXY_AUTH	403
95#define HTTP_PROTOCOL_ERROR	999
96
97#define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
98                            || (xyz) == HTTP_MOVED_TEMP \
99                            || (xyz) == HTTP_SEE_OTHER)
100
101
102
103/*****************************************************************************
104 * I/O functions for decoding chunked streams
105 */
106
107struct cookie
108{
109    int		 fd;
110    char	*buf;
111    size_t	 b_size;
112    size_t	 b_len;
113    int		 b_pos;
114    int		 eof;
115    int		 error;
116    long	 chunksize;
117#ifndef NDEBUG
118    long	 total;
119#endif
120};
121
122/*
123 * Get next chunk header
124 */
125static int
126_http_new_chunk(struct cookie *c)
127{
128    char *p;
129
130    if (_fetch_getln(c->fd, &c->buf, &c->b_size, &c->b_len) == -1)
131	return -1;
132
133    if (c->b_len < 2 || !ishexnumber(*c->buf))
134	return -1;
135
136    for (p = c->buf; !isspace(*p) && *p != ';' && p < c->buf + c->b_len; ++p)
137	if (!ishexnumber(*p))
138	    return -1;
139	else if (isdigit(*p))
140	    c->chunksize = c->chunksize * 16 + *p - '0';
141	else
142	    c->chunksize = c->chunksize * 16 + 10 + tolower(*p) - 'a';
143
144#ifndef NDEBUG
145    c->total += c->chunksize;
146    if (c->chunksize == 0)
147	fprintf(stderr, "\033[1m_http_fillbuf(): "
148		"end of last chunk\033[m\n");
149    else
150	fprintf(stderr, "\033[1m_http_fillbuf(): "
151		"new chunk: %ld (%ld)\033[m\n", c->chunksize, c->total);
152#endif
153
154    return c->chunksize;
155}
156
157/*
158 * Fill the input buffer, do chunk decoding on the fly
159 */
160static int
161_http_fillbuf(struct cookie *c)
162{
163    if (c->error)
164	return -1;
165    if (c->eof)
166	return 0;
167
168    if (c->chunksize == 0) {
169	switch (_http_new_chunk(c)) {
170	case -1:
171	    c->error = 1;
172	    return -1;
173	case 0:
174	    c->eof = 1;
175	    return 0;
176	}
177    }
178
179    if (c->b_size < c->chunksize) {
180	char *tmp;
181
182	if ((tmp = realloc(c->buf, c->chunksize)) == NULL)
183	    return -1;
184	c->buf = tmp;
185	c->b_size = c->chunksize;
186    }
187
188    if ((c->b_len = read(c->fd, c->buf, c->chunksize)) == -1)
189	return -1;
190    c->chunksize -= c->b_len;
191
192    if (c->chunksize == 0) {
193	char endl[2];
194	read(c->fd, endl, 2);
195    }
196
197    c->b_pos = 0;
198
199    return c->b_len;
200}
201
202/*
203 * Read function
204 */
205static int
206_http_readfn(void *v, char *buf, int len)
207{
208    struct cookie *c = (struct cookie *)v;
209    int l, pos;
210
211    if (c->error)
212	return -1;
213    if (c->eof)
214	return 0;
215
216    for (pos = 0; len > 0; pos += l, len -= l) {
217	/* empty buffer */
218	if (!c->buf || c->b_pos == c->b_len)
219	    if (_http_fillbuf(c) < 1)
220		break;
221	l = c->b_len - c->b_pos;
222	if (len < l)
223	    l = len;
224	bcopy(c->buf + c->b_pos, buf + pos, l);
225	c->b_pos += l;
226    }
227
228    if (!pos && c->error)
229	return -1;
230    return pos;
231}
232
233/*
234 * Write function
235 */
236static int
237_http_writefn(void *v, const char *buf, int len)
238{
239    struct cookie *c = (struct cookie *)v;
240
241    return write(c->fd, buf, len);
242}
243
244/*
245 * Close function
246 */
247static int
248_http_closefn(void *v)
249{
250    struct cookie *c = (struct cookie *)v;
251    int r;
252
253    r = close(c->fd);
254    if (c->buf)
255	free(c->buf);
256    free(c);
257    return r;
258}
259
260/*
261 * Wrap a file descriptor up
262 */
263static FILE *
264_http_funopen(int fd)
265{
266    struct cookie *c;
267    FILE *f;
268
269    if ((c = calloc(1, sizeof *c)) == NULL) {
270	_fetch_syserr();
271	return NULL;
272    }
273    c->fd = fd;
274    if (!(f = funopen(c, _http_readfn, _http_writefn, NULL, _http_closefn))) {
275	_fetch_syserr();
276	free(c);
277	return NULL;
278    }
279    return f;
280}
281
282
283/*****************************************************************************
284 * Helper functions for talking to the server and parsing its replies
285 */
286
287/* Header types */
288typedef enum {
289    hdr_syserror = -2,
290    hdr_error = -1,
291    hdr_end = 0,
292    hdr_unknown = 1,
293    hdr_content_length,
294    hdr_content_range,
295    hdr_last_modified,
296    hdr_location,
297    hdr_transfer_encoding
298} hdr;
299
300/* Names of interesting headers */
301static struct {
302    hdr		 num;
303    char	*name;
304} hdr_names[] = {
305    { hdr_content_length,	"Content-Length" },
306    { hdr_content_range,	"Content-Range" },
307    { hdr_last_modified,	"Last-Modified" },
308    { hdr_location,		"Location" },
309    { hdr_transfer_encoding,	"Transfer-Encoding" },
310    { hdr_unknown,		NULL },
311};
312
313static char	*reply_buf;
314static size_t	 reply_size;
315static size_t	 reply_length;
316
317/*
318 * Send a formatted line; optionally echo to terminal
319 */
320static int
321_http_cmd(int fd, char *fmt, ...)
322{
323    va_list ap;
324    size_t len;
325    char *msg;
326    int r;
327
328    va_start(ap, fmt);
329    len = vasprintf(&msg, fmt, ap);
330    va_end(ap);
331
332    if (msg == NULL) {
333	errno = ENOMEM;
334	_fetch_syserr();
335	return -1;
336    }
337
338    r = _fetch_putln(fd, msg, len);
339    free(msg);
340
341    if (r == -1) {
342	_fetch_syserr();
343	return -1;
344    }
345
346    return 0;
347}
348
349/*
350 * Get and parse status line
351 */
352static int
353_http_get_reply(int fd)
354{
355    if (_fetch_getln(fd, &reply_buf, &reply_size, &reply_length) == -1)
356	return -1;
357    /*
358     * A valid status line looks like "HTTP/m.n xyz reason" where m
359     * and n are the major and minor protocol version numbers and xyz
360     * is the reply code.
361     * We grok HTTP 1.0 and 1.1, so m must be 1 and n must be 0 or 1.
362     * We don't care about the reason phrase.
363     */
364    if (strncmp(reply_buf, "HTTP/1.", 7) != 0
365	|| (reply_buf[7] != '0' && reply_buf[7] != '1') || reply_buf[8] != ' '
366	|| !isdigit(reply_buf[9])
367	|| !isdigit(reply_buf[10])
368	|| !isdigit(reply_buf[11]))
369	return HTTP_PROTOCOL_ERROR;
370
371    return ((reply_buf[9] - '0') * 100
372	    + (reply_buf[10] - '0') * 10
373	    + (reply_buf[11] - '0'));
374}
375
376/*
377 * Check a header; if the type matches the given string, return a
378 * pointer to the beginning of the value.
379 */
380static char *
381_http_match(char *str, char *hdr)
382{
383    while (*str && *hdr && tolower(*str++) == tolower(*hdr++))
384	/* nothing */;
385    if (*str || *hdr != ':')
386	return NULL;
387    while (*hdr && isspace(*++hdr))
388	/* nothing */;
389    return hdr;
390}
391
392/*
393 * Get the next header and return the appropriate symbolic code.
394 */
395static hdr
396_http_next_header(int fd, char **p)
397{
398    int i;
399
400    if (_fetch_getln(fd, &reply_buf, &reply_size, &reply_length) == -1)
401	return hdr_syserror;
402    while (reply_length && isspace(reply_buf[reply_length-1]))
403	reply_length--;
404    reply_buf[reply_length] = 0;
405    if (reply_length == 0)
406	return hdr_end;
407    /*
408     * We could check for malformed headers but we don't really care.
409     * A valid header starts with a token immediately followed by a
410     * colon; a token is any sequence of non-control, non-whitespace
411     * characters except "()<>@,;:\\\"{}".
412     */
413    for (i = 0; hdr_names[i].num != hdr_unknown; i++)
414	if ((*p = _http_match(hdr_names[i].name, reply_buf)) != NULL)
415	    return hdr_names[i].num;
416    return hdr_unknown;
417}
418
419/*
420 * Parse a last-modified header
421 */
422static int
423_http_parse_mtime(char *p, time_t *mtime)
424{
425    char locale[64], *r;
426    struct tm tm;
427
428    strncpy(locale, setlocale(LC_TIME, NULL), sizeof locale);
429    setlocale(LC_TIME, "C");
430    r = strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
431    /* XXX should add support for date-2 and date-3 */
432    setlocale(LC_TIME, locale);
433    if (r == NULL)
434	return -1;
435    DEBUG(fprintf(stderr, "last modified: [\033[1m%04d-%02d-%02d "
436		  "%02d:%02d:%02d\033[m]\n",
437		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
438		  tm.tm_hour, tm.tm_min, tm.tm_sec));
439    *mtime = timegm(&tm);
440    return 0;
441}
442
443/*
444 * Parse a content-length header
445 */
446static int
447_http_parse_length(char *p, size_t *length)
448{
449    size_t len;
450
451    for (len = 0; *p && isdigit(*p); ++p)
452	len = len * 10 + (*p - '0');
453    DEBUG(fprintf(stderr, "content length: [\033[1m%d\033[m]\n", len));
454    *length = len;
455    return 0;
456}
457
458/*
459 * Parse a content-range header
460 */
461static int
462_http_parse_range(char *p, off_t *offset, size_t *length, size_t *size)
463{
464    int first, last, len;
465
466    if (strncasecmp(p, "bytes ", 6) != 0)
467	return -1;
468    for (first = 0, p += 6; *p && isdigit(*p); ++p)
469	first = first * 10 + *p - '0';
470    if (*p != '-')
471	return -1;
472    for (last = 0, ++p; *p && isdigit(*p); ++p)
473	last = last * 10 + *p - '0';
474    if (first > last || *p != '/')
475	return -1;
476    for (len = 0, ++p; *p && isdigit(*p); ++p)
477	len = len * 10 + *p - '0';
478    if (len < last - first + 1)
479	return -1;
480    DEBUG(fprintf(stderr, "content range: [\033[1m%d-%d/%d\033[m]\n",
481		  first, last, len));
482    *offset = first;
483    *length = last - first + 1;
484    *size = len;
485    return 0;
486}
487
488
489/*****************************************************************************
490 * Helper functions for authorization
491 */
492
493/*
494 * Base64 encoding
495 */
496static char *
497_http_base64(char *src)
498{
499    static const char base64[] =
500	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
501	"abcdefghijklmnopqrstuvwxyz"
502	"0123456789+/";
503    char *str, *dst;
504    size_t l;
505    int t, r;
506
507    l = strlen(src);
508    if ((str = malloc(((l + 2) / 3) * 4)) == NULL)
509	return NULL;
510    dst = str;
511    r = 0;
512
513    while (l >= 3) {
514	t = (src[0] << 16) | (src[1] << 8) | src[2];
515	dst[0] = base64[(t >> 18) & 0x3f];
516	dst[1] = base64[(t >> 12) & 0x3f];
517	dst[2] = base64[(t >> 6) & 0x3f];
518	dst[3] = base64[(t >> 0) & 0x3f];
519	src += 3; l -= 3;
520	dst += 4; r += 4;
521    }
522
523    switch (l) {
524    case 2:
525	t = (src[0] << 16) | (src[1] << 8);
526	dst[0] = base64[(t >> 18) & 0x3f];
527	dst[1] = base64[(t >> 12) & 0x3f];
528	dst[2] = base64[(t >> 6) & 0x3f];
529	dst[3] = '=';
530	dst += 4;
531	r += 4;
532	break;
533    case 1:
534	t = src[0] << 16;
535	dst[0] = base64[(t >> 18) & 0x3f];
536	dst[1] = base64[(t >> 12) & 0x3f];
537	dst[2] = dst[3] = '=';
538	dst += 4;
539	r += 4;
540	break;
541    case 0:
542	break;
543    }
544
545    *dst = 0;
546    return str;
547}
548
549/*
550 * Encode username and password
551 */
552static int
553_http_basic_auth(int fd, char *hdr, char *usr, char *pwd)
554{
555    char *upw, *auth;
556    int r;
557
558    if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
559	return -1;
560    auth = _http_base64(upw);
561    free(upw);
562    if (auth == NULL)
563	return -1;
564    r = _http_cmd(fd, "%s: Basic %s", hdr, auth);
565    free(auth);
566    return r;
567}
568
569/*
570 * Send an authorization header
571 */
572static int
573_http_authorize(int fd, char *hdr, char *p)
574{
575    /* basic authorization */
576    if (strncasecmp(p, "basic:", 6) == 0) {
577	char *user, *pwd, *str;
578	int r;
579
580	/* skip realm */
581	for (p += 6; *p && *p != ':'; ++p)
582	    /* nothing */ ;
583	if (!*p || strchr(++p, ':') == NULL)
584	    return -1;
585	if ((str = strdup(p)) == NULL)
586	    return -1; /* XXX */
587	user = str;
588	pwd = strchr(str, ':');
589	*pwd++ = '\0';
590	r = _http_basic_auth(fd, hdr, user, pwd);
591	free(str);
592	return r;
593    }
594    return -1;
595}
596
597
598/*****************************************************************************
599 * Helper functions for connecting to a server or proxy
600 */
601
602/*
603 * Connect to the specified HTTP proxy server.
604 */
605static int
606_http_proxy_connect(char *proxy, int af, int verbose)
607{
608    char *hostname, *p;
609    int fd, port;
610
611    /* get hostname */
612    hostname = NULL;
613#ifdef INET6
614    /* host part can be an IPv6 address enclosed in square brackets */
615    if (*proxy == '[') {
616	if ((p = strchr(proxy, ']')) == NULL) {
617	    /* no terminating bracket */
618	    /* XXX should set an error code */
619	    goto ouch;
620	}
621	if (p[1] != '\0' && p[1] != ':') {
622	    /* garbage after address */
623	    /* XXX should set an error code */
624	    goto ouch;
625	}
626	if ((hostname = malloc(p - proxy)) == NULL) {
627	    errno = ENOMEM;
628	    _fetch_syserr();
629	    goto ouch;
630	}
631	strncpy(hostname, proxy + 1, p - proxy - 1);
632	hostname[p - proxy - 1] = '\0';
633	++p;
634    } else {
635#endif /* INET6 */
636	if ((p = strchr(proxy, ':')) == NULL)
637	    p = strchr(proxy, '\0');
638	if ((hostname = malloc(p - proxy + 1)) == NULL) {
639	    errno = ENOMEM;
640	    _fetch_syserr();
641	    goto ouch;
642	}
643	strncpy(hostname, proxy, p - proxy);
644	hostname[p - proxy] = '\0';
645#ifdef INET6
646    }
647#endif /* INET6 */
648    DEBUG(fprintf(stderr, "proxy name: [%s]\n", hostname));
649
650    /* get port number */
651    port = 0;
652    if (*p == ':') {
653	++p;
654	if (strspn(p, "0123456789") != strlen(p) || strlen(p) > 5) {
655	    /* port number is non-numeric or too long */
656	    /* XXX should set an error code */
657	    goto ouch;
658	}
659	port = atoi(p);
660	if (port < 1 || port > 65535) {
661	    /* port number is out of range */
662	    /* XXX should set an error code */
663	    goto ouch;
664	}
665    }
666
667    if (!port) {
668#if 0
669	/*
670	 * commented out, since there is currently no service name
671	 * for HTTP proxies
672	 */
673	struct servent *se;
674
675	if ((se = getservbyname("xxxx", "tcp")) != NULL)
676	    port = ntohs(se->s_port);
677	else
678#endif
679	    port = 3128;
680    }
681    DEBUG(fprintf(stderr, "proxy port: %d\n", port));
682
683    /* connect */
684    if ((fd = _fetch_connect(hostname, port, af, verbose)) == -1)
685	_fetch_syserr();
686    return fd;
687
688 ouch:
689    if (hostname)
690	free(hostname);
691    return -1;
692}
693
694/*
695 * Connect to the correct HTTP server or proxy.
696 */
697static int
698_http_connect(struct url *URL, int *proxy, char *flags)
699{
700    int direct, verbose;
701    int af, fd;
702    char *p;
703
704#ifdef INET6
705    af = AF_UNSPEC;
706#else
707    af = AF_INET;
708#endif
709
710    direct = (flags && strchr(flags, 'd'));
711    verbose = (flags && strchr(flags, 'v'));
712    if (flags && strchr(flags, '4'))
713	af = AF_INET;
714    else if (flags && strchr(flags, '6'))
715	af = AF_INET6;
716
717    /* check port */
718    if (!URL->port) {
719	struct servent *se;
720
721	/* Scheme can be ftp if we're using a proxy */
722	if (strcasecmp(URL->scheme, "ftp") == 0)
723	    if ((se = getservbyname("ftp", "tcp")) != NULL)
724		URL->port = ntohs(se->s_port);
725	    else
726		URL->port = 21;
727	else
728	    if ((se = getservbyname("http", "tcp")) != NULL)
729		URL->port = ntohs(se->s_port);
730	    else
731		URL->port = 80;
732    }
733
734    if (!direct && (p = getenv("HTTP_PROXY")) != NULL && *p != '\0') {
735	/* attempt to connect to proxy server */
736	if ((fd = _http_proxy_connect(p, af, verbose)) == -1)
737	    return -1;
738	*proxy = 1;
739    } else {
740	/* if no proxy is configured, try direct */
741	if (strcasecmp(URL->scheme, "ftp") == 0) {
742	    /* can't talk http to an ftp server */
743	    /* XXX should set an error code */
744	    return -1;
745	}
746	if ((fd = _fetch_connect(URL->host, URL->port, af, verbose)) == -1)
747	    /* _fetch_connect() has already set an error code */
748	    return -1;
749	*proxy = 0;
750    }
751
752    return fd;
753}
754
755
756/*****************************************************************************
757 * Core
758 */
759
760/*
761 * Send a request and process the reply
762 */
763static FILE *
764_http_request(struct url *URL, char *op, struct url_stat *us, char *flags)
765{
766    struct url *url, *new;
767    int chunked, need_auth, noredirect, proxy, verbose;
768    int code, fd, i, n;
769    off_t offset;
770    size_t clength, length, size;
771    time_t mtime;
772    char *p;
773    FILE *f;
774    hdr h;
775    char *host;
776#ifdef INET6
777    char hbuf[MAXHOSTNAMELEN + 1];
778#endif
779
780    noredirect = (flags && strchr(flags, 'A'));
781    verbose = (flags && strchr(flags, 'v'));
782
783    /* try the provided URL first */
784    url = URL;
785
786    /* if the A flag is set, we only get one try */
787    n = noredirect ? 1 : MAX_REDIRECT;
788    i = 0;
789
790    do {
791	new = NULL;
792	chunked = 0;
793	need_auth = 0;
794	offset = 0;
795	clength = -1;
796	length = -1;
797	size = -1;
798	mtime = 0;
799    retry:
800	/* connect to server or proxy */
801	if ((fd = _http_connect(url, &proxy, flags)) == -1)
802	    goto ouch;
803
804	host = url->host;
805#ifdef INET6
806	if (strchr(url->host, ':')) {
807	    snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
808	    host = hbuf;
809	}
810#endif
811
812	/* send request */
813	if (verbose)
814	    _fetch_info("requesting %s://%s:%d%s",
815			url->scheme, host, url->port, url->doc);
816	if (proxy) {
817	    _http_cmd(fd, "%s %s://%s:%d%s HTTP/1.1",
818		      op, url->scheme, host, url->port, url->doc);
819	} else {
820	    _http_cmd(fd, "%s %s HTTP/1.1",
821		      op, url->doc);
822	}
823
824	/* proxy authorization */
825	if (proxy && (p = getenv("HTTP_PROXY_AUTH")) != NULL && *p != '\0')
826	    _http_authorize(fd, "Proxy-Authorization", p);
827
828	/* server authorization */
829	if (need_auth) {
830	    if (*url->user || *url->pwd)
831		_http_basic_auth(fd, "Authorization",
832				 url->user ? url->user : "",
833				 url->pwd ? url->pwd : "");
834	    else if ((p = getenv("HTTP_AUTH")) != NULL && *p != '\0')
835		_http_authorize(fd, "Authorization", p);
836	    else {
837		_http_seterr(HTTP_NEED_AUTH);
838		goto ouch;
839	    }
840	}
841
842	/* other headers */
843	_http_cmd(fd, "Host: %s:%d", host, url->port);
844	_http_cmd(fd, "User-Agent: %s " _LIBFETCH_VER, __progname);
845	if (url->offset)
846	    _http_cmd(fd, "Range: bytes=%lld-", url->offset);
847	_http_cmd(fd, "Connection: close");
848	_http_cmd(fd, "");
849
850	/* get reply */
851	switch ((code = _http_get_reply(fd))) {
852	case HTTP_OK:
853	case HTTP_PARTIAL:
854	    /* fine */
855	    break;
856	case HTTP_MOVED_PERM:
857	case HTTP_MOVED_TEMP:
858	    /*
859	     * Not so fine, but we still have to read the headers to
860	     * get the new location.
861	     */
862	    break;
863	case HTTP_NEED_AUTH:
864	    if (need_auth) {
865		/*
866		 * We already sent out authorization code, so there's
867		 * nothing more we can do.
868		 */
869		_http_seterr(code);
870		goto ouch;
871	    }
872	    /* try again, but send the password this time */
873	    if (verbose)
874		_fetch_info("server requires authorization");
875	    need_auth = 1;
876	    close(fd);
877	    goto retry;
878	case HTTP_NEED_PROXY_AUTH:
879	    /*
880	     * If we're talking to a proxy, we already sent our proxy
881	     * authorization code, so there's nothing more we can do.
882	     */
883	    _http_seterr(code);
884	    goto ouch;
885	case HTTP_PROTOCOL_ERROR:
886	    /* fall through */
887	case -1:
888	    _fetch_syserr();
889	    goto ouch;
890	default:
891	    _http_seterr(code);
892	    goto ouch;
893	}
894
895	/* get headers */
896	do {
897	    switch ((h = _http_next_header(fd, &p))) {
898	    case hdr_syserror:
899		_fetch_syserr();
900		goto ouch;
901	    case hdr_error:
902		_http_seterr(HTTP_PROTOCOL_ERROR);
903		goto ouch;
904	    case hdr_content_length:
905		_http_parse_length(p, &clength);
906		break;
907	    case hdr_content_range:
908		_http_parse_range(p, &offset, &length, &size);
909		break;
910	    case hdr_last_modified:
911		_http_parse_mtime(p, &mtime);
912		break;
913	    case hdr_location:
914		if (!HTTP_REDIRECT(code))
915		    break;
916		if (new)
917		    free(new);
918		if (verbose)
919		    _fetch_info("%d redirect to %s", code, p);
920		if (*p == '/')
921		    /* absolute path */
922		    new = fetchMakeURL(url->scheme, url->host, url->port, p,
923				       url->user, url->pwd);
924		else
925		    new = fetchParseURL(p);
926		if (new == NULL) {
927		    /* XXX should set an error code */
928		    DEBUG(fprintf(stderr, "failed to parse new URL\n"));
929		    goto ouch;
930		}
931		if (!*new->user && !*new->pwd) {
932		    strcpy(new->user, url->user);
933		    strcpy(new->pwd, url->pwd);
934		}
935		new->offset = url->offset;
936		new->length = url->length;
937		break;
938	    case hdr_transfer_encoding:
939		/* XXX weak test*/
940		chunked = (strcasecmp(p, "chunked") == 0);
941		break;
942	    case hdr_end:
943		/* fall through */
944	    case hdr_unknown:
945		/* ignore */
946		break;
947	    }
948	} while (h > hdr_end);
949
950	/* we either have a hit, or a redirect with no Location: header */
951	if (code == HTTP_OK || code == HTTP_PARTIAL || !new)
952	    break;
953
954	/* we have a redirect */
955	close(fd);
956	fd = -1;
957	if (url != URL)
958	    fetchFreeURL(url);
959	url = new;
960    } while (++i < n);
961
962    /* no success */
963    if (fd == -1) {
964	_http_seterr(code);
965	goto ouch;
966    }
967
968    DEBUG(fprintf(stderr, "offset: %lld, length: %d, size: %d, clength: %d\n",
969		  offset, length, size, clength));
970
971    /* check for inconsistencies */
972    if (clength != -1 && length != -1 && clength != length) {
973	_http_seterr(HTTP_PROTOCOL_ERROR);
974	goto ouch;
975    }
976    if (clength == -1)
977	clength = length;
978    if (clength != -1)
979	length = offset + clength;
980    if (length != -1 && size != -1 && length != size) {
981	_http_seterr(HTTP_PROTOCOL_ERROR);
982	goto ouch;
983    }
984    if (size == -1)
985	size = length;
986
987    /* fill in stats */
988    if (us) {
989	us->size = size;
990	us->atime = us->mtime = mtime;
991    }
992
993    /* too far? */
994    if (offset > URL->offset) {
995	_http_seterr(HTTP_PROTOCOL_ERROR);
996	goto ouch;
997    }
998
999    /* report back real offset and size */
1000    URL->offset = offset;
1001    URL->length = clength;
1002
1003    /* wrap it up in a FILE */
1004    if ((f = chunked ? _http_funopen(fd) : fdopen(fd, "r")) == NULL) {
1005	_fetch_syserr();
1006	goto ouch;
1007    }
1008
1009    if (url != URL)
1010	fetchFreeURL(url);
1011
1012    return f;
1013
1014 ouch:
1015    if (url != URL)
1016	fetchFreeURL(url);
1017    if (fd != -1)
1018	close(fd);
1019    return NULL;
1020}
1021
1022
1023/*****************************************************************************
1024 * Entry points
1025 */
1026
1027/*
1028 * Retrieve and stat a file by HTTP
1029 */
1030FILE *
1031fetchXGetHTTP(struct url *URL, struct url_stat *us, char *flags)
1032{
1033    return _http_request(URL, "GET", us, flags);
1034}
1035
1036/*
1037 * Retrieve a file by HTTP
1038 */
1039FILE *
1040fetchGetHTTP(struct url *URL, char *flags)
1041{
1042    return fetchXGetHTTP(URL, NULL, flags);
1043}
1044
1045/*
1046 * Store a file by HTTP
1047 */
1048FILE *
1049fetchPutHTTP(struct url *URL, char *flags)
1050{
1051    warnx("fetchPutHTTP(): not implemented");
1052    return NULL;
1053}
1054
1055/*
1056 * Get an HTTP document's metadata
1057 */
1058int
1059fetchStatHTTP(struct url *URL, struct url_stat *us, char *flags)
1060{
1061    FILE *f;
1062
1063    if ((f = _http_request(URL, "HEAD", us, flags)) == NULL)
1064	return -1;
1065    fclose(f);
1066    return 0;
1067}
1068
1069/*
1070 * List a directory
1071 */
1072struct url_ent *
1073fetchListHTTP(struct url *url, char *flags)
1074{
1075    warnx("fetchListHTTP(): not implemented");
1076    return NULL;
1077}
1078