fetch.c 13.5 KB
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/*	$NetBSD: fetch.c,v 1.19 2009/08/11 20:48:06 joerg Exp $	*/
/*-
 * Copyright (c) 1998-2004 Dag-Erling Codan Smrgrav
 * Copyright (c) 2008 Joerg Sonnenberger <joerg@NetBSD.org>
 * 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
 *    in this position and unchanged.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * $FreeBSD: fetch.c,v 1.41 2007/12/19 00:26:36 des Exp $
 */

#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "fetch.h"
#include "common.h"

auth_t	 fetchAuthMethod;
int	 fetchLastErrCode;
char	 fetchLastErrString[MAXERRSTRING];
int	 fetchTimeout;
volatile int	 fetchRestartCalls = 1;
int	 fetchDebug;


/*** Local data **************************************************************/

/*
 * Error messages for parser errors
 */
#define URL_MALFORMED		1
#define URL_BAD_SCHEME		2
#define URL_BAD_PORT		3
static struct fetcherr url_errlist[] = {
	{ URL_MALFORMED,	FETCH_URL,	"Malformed URL" },
	{ URL_BAD_SCHEME,	FETCH_URL,	"Invalid URL scheme" },
	{ URL_BAD_PORT,		FETCH_URL,	"Invalid server port" },
	{ -1,			FETCH_UNKNOWN,	"Unknown parser error" }
};


/*** Public API **************************************************************/

/*
 * Select the appropriate protocol for the URL scheme, and return a
 * read-only stream connected to the document referenced by the URL.
 * Also fill out the struct url_stat.
 */
fetchIO *
fetchXGet(struct url *URL, struct url_stat *us, const char *flags)
{

	if (us != NULL) {
		us->size = -1;
		us->atime = us->mtime = 0;
	}
	if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
		return (fetchXGetFile(URL, us, flags));
	else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
		return (fetchXGetFTP(URL, us, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
		return (fetchXGetHTTP(URL, us, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
		return (fetchXGetHTTP(URL, us, flags));
	url_seterr(URL_BAD_SCHEME);
	return (NULL);
}

/*
 * Select the appropriate protocol for the URL scheme, and return a
 * read-only stream connected to the document referenced by the URL.
 */
fetchIO *
fetchGet(struct url *URL, const char *flags)
{
	return (fetchXGet(URL, NULL, flags));
}

/*
 * Select the appropriate protocol for the URL scheme, and return a
 * write-only stream connected to the document referenced by the URL.
 */
fetchIO *
fetchPut(struct url *URL, const char *flags)
{

	if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
		return (fetchPutFile(URL, flags));
	else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
		return (fetchPutFTP(URL, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
		return (fetchPutHTTP(URL, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
		return (fetchPutHTTP(URL, flags));
	url_seterr(URL_BAD_SCHEME);
	return (NULL);
}

/*
 * Select the appropriate protocol for the URL scheme, and return the
 * size of the document referenced by the URL if it exists.
 */
int
fetchStat(struct url *URL, struct url_stat *us, const char *flags)
{

	if (us != NULL) {
		us->size = -1;
		us->atime = us->mtime = 0;
	}
	if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
		return (fetchStatFile(URL, us, flags));
	else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
		return (fetchStatFTP(URL, us, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
		return (fetchStatHTTP(URL, us, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
		return (fetchStatHTTP(URL, us, flags));
	url_seterr(URL_BAD_SCHEME);
	return (-1);
}

/*
 * Select the appropriate protocol for the URL scheme, and return a
 * list of files in the directory pointed to by the URL.
 */
int
fetchList(struct url_list *ue, struct url *URL, const char *pattern,
    const char *flags)
{

	if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
		return (fetchListFile(ue, URL, pattern, flags));
	else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
		return (fetchListFTP(ue, URL, pattern, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
		return (fetchListHTTP(ue, URL, pattern, flags));
	else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
		return (fetchListHTTP(ue, URL, pattern, flags));
	url_seterr(URL_BAD_SCHEME);
	return -1;
}

/*
 * Attempt to parse the given URL; if successful, call fetchXGet().
 */
fetchIO *
fetchXGetURL(const char *URL, struct url_stat *us, const char *flags)
{
	struct url *u;
	fetchIO *f;

	if ((u = fetchParseURL(URL)) == NULL)
		return (NULL);

	f = fetchXGet(u, us, flags);

	fetchFreeURL(u);
	return (f);
}

/*
 * Attempt to parse the given URL; if successful, call fetchGet().
 */
fetchIO *
fetchGetURL(const char *URL, const char *flags)
{
	return (fetchXGetURL(URL, NULL, flags));
}

/*
 * Attempt to parse the given URL; if successful, call fetchPut().
 */
fetchIO *
fetchPutURL(const char *URL, const char *flags)
{
	struct url *u;
	fetchIO *f;

	if ((u = fetchParseURL(URL)) == NULL)
		return (NULL);

	f = fetchPut(u, flags);

	fetchFreeURL(u);
	return (f);
}

/*
 * Attempt to parse the given URL; if successful, call fetchStat().
 */
int
fetchStatURL(const char *URL, struct url_stat *us, const char *flags)
{
	struct url *u;
	int s;

	if ((u = fetchParseURL(URL)) == NULL)
		return (-1);

	s = fetchStat(u, us, flags);

	fetchFreeURL(u);
	return (s);
}

/*
 * Attempt to parse the given URL; if successful, call fetchList().
 */
int
fetchListURL(struct url_list *ue, const char *URL, const char *pattern,
    const char *flags)
{
	struct url *u;
	int rv;

	if ((u = fetchParseURL(URL)) == NULL)
		return -1;

	rv = fetchList(ue, u, pattern, flags);

	fetchFreeURL(u);
	return rv;
}

/*
 * Make a URL
 */
struct url *
fetchMakeURL(const char *scheme, const char *host, int port, const char *doc,
    const char *user, const char *pwd)
{
	struct url *u;

	if (!scheme || (!host && !doc)) {
		url_seterr(URL_MALFORMED);
		return (NULL);
	}

	if (port < 0 || port > 65535) {
		url_seterr(URL_BAD_PORT);
		return (NULL);
	}

	/* allocate struct url */
	if ((u = calloc(1, sizeof(*u))) == NULL) {
		fetch_syserr();
		return (NULL);
	}

	if ((u->doc = strdup(doc ? doc : "/")) == NULL) {
		fetch_syserr();
		free(u);
		return (NULL);
	}

#define seturl(x) snprintf(u->x, sizeof(u->x), "%s", x)
	seturl(scheme);
	seturl(host);
	seturl(user);
	seturl(pwd);
#undef seturl
	u->port = port;

	return (u);
}

int
fetch_urlpath_safe(char x)
{
	if ((x >= '0' && x <= '9') || (x >= 'A' && x <= 'Z') ||
	    (x >= 'a' && x <= 'z'))
		return 1;

	switch (x) {
	case '$':
	case '-':
	case '_':
	case '.':
	case '+':
	case '!':
	case '*':
	case '\'':
	case '(':
	case ')':
	case ',':
	/* The following are allowed in segment and path components: */
	case '?':
	case ':':
	case '@':
	case '&':
	case '=':
	case '/':
	case ';':
	/* If something is already quoted... */
	case '%':
		return 1;
	default:
		return 0;
	}
}

/*
 * Copy an existing URL.
 */
struct url *
fetchCopyURL(const struct url *src)
{
	struct url *dst;
	char *doc;

	/* allocate struct url */
	if ((dst = malloc(sizeof(*dst))) == NULL) {
		fetch_syserr();
		return (NULL);
	}
	if ((doc = strdup(src->doc)) == NULL) {
		fetch_syserr();
		free(dst);
		return (NULL);
	}
	*dst = *src;
	dst->doc = doc;

	return dst;
}

/*
 * Split an URL into components. URL syntax is:
 * [method:/][/[user[:pwd]@]host[:port]/][document]
 * This almost, but not quite, RFC1738 URL syntax.
 */
struct url *
fetchParseURL(const char *URL)
{
	const char *p, *q;
	struct url *u;
	size_t i, count;
	int pre_quoted;

	/* allocate struct url */
	if ((u = calloc(1, sizeof(*u))) == NULL) {
		fetch_syserr();
		return (NULL);
	}

	if (*URL == '/') {
		pre_quoted = 0;
		strcpy(u->scheme, SCHEME_FILE);
		p = URL;
		goto quote_doc;
	}
	if (strncmp(URL, "file:", 5) == 0) {
		pre_quoted = 1;
		strcpy(u->scheme, SCHEME_FILE);
		URL += 5;
		if (URL[0] != '/' || URL[1] != '/' || URL[2] != '/') {
			url_seterr(URL_MALFORMED);
			goto ouch;
		}
		p = URL + 2;
		goto quote_doc;
	}
	if (strncmp(URL, "http:", 5) == 0 ||
	    strncmp(URL, "https:", 6) == 0) {
		pre_quoted = 1;
		if (URL[4] == ':') {
			strcpy(u->scheme, SCHEME_HTTP);
			URL += 5;
		} else {
			strcpy(u->scheme, SCHEME_HTTPS);
			URL += 6;
		}

		if (URL[0] != '/' || URL[1] != '/') {
			url_seterr(URL_MALFORMED);
			goto ouch;
		}
		URL += 2;
		p = URL;
		goto find_user;
	}
	if (strncmp(URL, "ftp:", 4) == 0) {
		pre_quoted = 1;
		strcpy(u->scheme, SCHEME_FTP);
		URL += 4;
		if (URL[0] != '/' || URL[1] != '/') {
			url_seterr(URL_MALFORMED);
			goto ouch;
		}
		URL += 2;
		p = URL;
		goto find_user;			
	}

	url_seterr(URL_BAD_SCHEME);
	goto ouch;

find_user:
	p = strpbrk(URL, "/@");
	if (p != NULL && *p == '@') {
		/* username */
		for (q = URL, i = 0; (*q != ':') && (*q != '@'); q++) {
			if (i < URL_USERLEN)
				u->user[i++] = *q;
		}

		/* password */
		if (*q == ':') {
			for (q++, i = 0; (*q != '@'); q++)
				if (i < URL_PWDLEN)
					u->pwd[i++] = *q;
		}

		p++;
	} else {
		p = URL;
	}

	/* hostname */
	if (*p == '[' && (q = strchr(p + 1, ']')) != NULL &&
	    (*++q == '\0' || *q == '/' || *q == ':')) {
		if ((i = q - p - 2) > URL_HOSTLEN)
			i = URL_HOSTLEN;
		strncpy(u->host, ++p, i);
		p = q;
451
	} else {
452 453 454
		for (i = 0; *p && (*p != '/') && (*p != ':'); p++)
			if (i < URL_HOSTLEN)
				u->host[i++] = *p;
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

	/* port */
	if (*p == ':') {
		for (q = ++p; *q && (*q != '/'); q++)
			if (isdigit((unsigned char)*q))
				u->port = u->port * 10 + (*q - '0');
			else {
				/* invalid port */
				url_seterr(URL_BAD_PORT);
				goto ouch;
			}
		p = q;
	}

	/* document */
	if (!*p)
		p = "/";

quote_doc:
	count = 1;
	for (i = 0; p[i] != '\0'; ++i) {
		if ((!pre_quoted && p[i] == '%') ||
		    !fetch_urlpath_safe(p[i]))
			count += 3;
		else
			++count;
	}

	if ((u->doc = malloc(count)) == NULL) {
		fetch_syserr();
		goto ouch;
	}
	for (i = 0; *p != '\0'; ++p) {
		if ((!pre_quoted && *p == '%') ||
		    !fetch_urlpath_safe(*p)) {
			u->doc[i++] = '%';
			if ((unsigned char)*p < 160)
				u->doc[i++] = '0' + ((unsigned char)*p) / 16;
			else
				u->doc[i++] = 'a' - 10 + ((unsigned char)*p) / 16;
			if ((unsigned char)*p % 16 < 10)
				u->doc[i++] = '0' + ((unsigned char)*p) % 16;
			else
				u->doc[i++] = 'a' - 10 + ((unsigned char)*p) % 16;
		} else
			u->doc[i++] = *p;
	}
	u->doc[i] = '\0';

	return (u);

ouch:
	free(u);
	return (NULL);
}

/*
 * Free a URL
 */
void
fetchFreeURL(struct url *u)
{
	free(u->doc);
	free(u);
}

static char
xdigit2digit(char digit)
{
	digit = tolower((unsigned char)digit);
	if (digit >= 'a' && digit <= 'f')
		digit = digit - 'a' + 10;
	else
		digit = digit - '0';

	return digit;
}

/*
 * Unquote whole URL.
 * Skips optional parts like query or fragment identifier.
 */ 
char *
fetchUnquotePath(struct url *url)
{
	char *unquoted;
	const char *iter;
	size_t i;

	if ((unquoted = malloc(strlen(url->doc) + 1)) == NULL)
		return NULL;

	for (i = 0, iter = url->doc; *iter != '\0'; ++iter) {
		if (*iter == '#' || *iter == '?')
			break;
		if (iter[0] != '%' ||
		    !isxdigit((unsigned char)iter[1]) ||
		    !isxdigit((unsigned char)iter[2])) {
			unquoted[i++] = *iter;
			continue;
		}
		unquoted[i++] = xdigit2digit(iter[1]) * 16 +
		    xdigit2digit(iter[2]);
		iter += 2;
	}
	unquoted[i] = '\0';
	return unquoted;
}


/*
 * Extract the file name component of a URL.
 */
char *
fetchUnquoteFilename(struct url *url)
{
	char *unquoted, *filename;
	const char *last_slash;

	if ((unquoted = fetchUnquotePath(url)) == NULL)
		return NULL;

	if ((last_slash = strrchr(unquoted, '/')) == NULL)
		return unquoted;
	filename = strdup(last_slash + 1);
	free(unquoted);
	return filename;
}

char *
fetchStringifyURL(const struct url *url)
{
	size_t total;
	char *doc;

	/* scheme :// user : pwd @ host :port doc */
	total = strlen(url->scheme) + 3 + strlen(url->user) + 1 +
	    strlen(url->pwd) + 1 + strlen(url->host) + 6 + strlen(url->doc) + 1;
	if ((doc = malloc(total)) == NULL)
		return NULL;
	if (url->port != 0)
		snprintf(doc, total, "%s%s%s%s%s%s%s:%d%s",
		    url->scheme,
		    url->scheme[0] != '\0' ? "://" : "",
		    url->user,
		    url->pwd[0] != '\0' ? ":" : "",
		    url->pwd,
		    url->user[0] != '\0' || url->pwd[0] != '\0' ? "@" : "",
		    url->host,
		    (int)url->port,
		    url->doc);
	else {
		snprintf(doc, total, "%s%s%s%s%s%s%s%s",
		    url->scheme,
		    url->scheme[0] != '\0' ? "://" : "",
		    url->user,
		    url->pwd[0] != '\0' ? ":" : "",
		    url->pwd,
		    url->user[0] != '\0' || url->pwd[0] != '\0' ? "@" : "",
		    url->host,
		    url->doc);
	}
	return doc;
}