Added libfetch linux port + misc changes

1 files changed, 1225 insertions, 0 deletions

diff --git a/lib/libfetch/http.c b/lib/libfetch/http.c
new file mode 100644
index 00000000..c173b5d5
--- /dev/null
+++ b/lib/libfetch/http.c
@@ -0,0 +1,1225 @@
+/*-
+ * Copyright (c) 2000-2004 Dag-Erling Coïdan Smørgrav
+ * 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.
+ */
+
+#define _GNU_SOURCE
+
+#include <sys/cdefs.h>
+
+/*
+ * The following copyright applies to the base64 code:
+ *
+ *-
+ * Copyright 1997 Massachusetts Institute of Technology
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose and without fee is hereby
+ * granted, provided that both the above copyright notice and this
+ * permission notice appear in all copies, that both the above
+ * copyright notice and this permission notice appear in all
+ * supporting documentation, and that the name of M.I.T. not be used
+ * in advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.  M.I.T. makes
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
+ * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
+ * SHALL M.I.T. 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.
+ */
+
+#include <sys/param.h>
+#include <sys/socket.h>
+
+#include <ctype.h>
+#include <libio.h>
+#include <err.h>
+#include <errno.h>
+#include <locale.h>
+#include <netdb.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+
+#include "fetch.h"
+#include "common.h"
+#include "httperr.h"
+
+/* Maximum number of redirects to follow */
+#define MAX_REDIRECT 5
+
+/* Symbolic names for reply codes we care about */
+#define HTTP_OK			200
+#define HTTP_PARTIAL		206
+#define HTTP_MOVED_PERM		301
+#define HTTP_MOVED_TEMP		302
+#define HTTP_SEE_OTHER		303
+#define HTTP_NEED_AUTH		401
+#define HTTP_NEED_PROXY_AUTH	407
+#define HTTP_BAD_RANGE		416
+#define HTTP_PROTOCOL_ERROR	999
+
+#define HTTP_REDIRECT(xyz) ((xyz) == HTTP_MOVED_PERM \
+			    || (xyz) == HTTP_MOVED_TEMP \
+			    || (xyz) == HTTP_SEE_OTHER)
+
+#define HTTP_ERROR(xyz) ((xyz) > 400 && (xyz) < 599)
+
+
+/*****************************************************************************
+ * I/O functions for decoding chunked streams
+ */
+
+struct httpio
+{
+	conn_t		*conn;		/* connection */
+	int		 chunked;	/* chunked mode */
+	char		*buf;		/* chunk buffer */
+	size_t		 bufsize;	/* size of chunk buffer */
+	ssize_t		 buflen;	/* amount of data currently in buffer */
+	int		 bufpos;	/* current read offset in buffer */
+	int		 eof;		/* end-of-file flag */
+	int		 error;		/* error flag */
+	size_t		 chunksize;	/* remaining size of current chunk */
+#ifndef NDEBUG
+	size_t		 total;
+#endif
+};
+
+/*
+ * Get next chunk header
+ */
+static int
+_http_new_chunk(struct httpio *io)
+{
+    char hexdigits[23] = "0123456789abcdefABCDEF\0";
+	char *p = NULL;
+
+	if (_fetch_getln(io->conn) == -1)
+		return (-1);
+
+	if (io->conn->buflen < 2 || !strchr(hexdigits, *p))
+		return (-1);
+
+	for (p = io->conn->buf; *p && !isspace(*p); ++p) {
+		if (*p == ';')
+			break;
+		if (!strchr(hexdigits, *p))
+			return (-1);
+		if (isdigit(*p)) {
+			io->chunksize = io->chunksize * 16 +
+			    *p - '0';
+		} else {
+			io->chunksize = io->chunksize * 16 +
+			    10 + tolower(*p) - 'a';
+		}
+	}
+
+#ifndef NDEBUG
+	if (fetchDebug) {
+		io->total += io->chunksize;
+		if (io->chunksize == 0)
+			fprintf(stderr, "%s(): end of last chunk\n", __func__);
+		else
+			fprintf(stderr, "%s(): new chunk: %lu (%lu)\n",
+			    __func__, (unsigned long)io->chunksize,
+			    (unsigned long)io->total);
+	}
+#endif
+
+	return (io->chunksize);
+}
+
+/*
+ * Grow the input buffer to at least len bytes
+ */
+static inline int
+_http_growbuf(struct httpio *io, size_t len)
+{
+	char *tmp;
+
+	if (io->bufsize >= len)
+		return (0);
+
+	if ((tmp = realloc(io->buf, len)) == NULL)
+		return (-1);
+	io->buf = tmp;
+	io->bufsize = len;
+	return (0);
+}
+
+/*
+ * Fill the input buffer, do chunk decoding on the fly
+ */
+static int
+_http_fillbuf(struct httpio *io, size_t len)
+{
+	if (io->error)
+		return (-1);
+	if (io->eof)
+		return (0);
+
+	if (io->chunked == 0) {
+		if (_http_growbuf(io, len) == -1)
+			return (-1);
+		if ((io->buflen = _fetch_read(io->conn, io->buf, len)) == -1) {
+			io->error = 1;
+			return (-1);
+		}
+		io->bufpos = 0;
+		return (io->buflen);
+	}
+
+	if (io->chunksize == 0) {
+		switch (_http_new_chunk(io)) {
+		case -1:
+			io->error = 1;
+			return (-1);
+		case 0:
+			io->eof = 1;
+			return (0);
+		}
+	}
+
+	if (len > io->chunksize)
+		len = io->chunksize;
+	if (_http_growbuf(io, len) == -1)
+		return (-1);
+	if ((io->buflen = _fetch_read(io->conn, io->buf, len)) == -1) {
+		io->error = 1;
+		return (-1);
+	}
+	io->chunksize -= io->buflen;
+
+	if (io->chunksize == 0) {
+		char endl[2];
+
+		if (_fetch_read(io->conn, endl, 2) != 2 ||
+		    endl[0] != '\r' || endl[1] != '\n')
+			return (-1);
+	}
+
+	io->bufpos = 0;
+
+	return (io->buflen);
+}
+
+/*
+ * Read function
+ */
+static int
+_http_readfn(void *v, char *buf, int len)
+{
+	struct httpio *io = (struct httpio *)v;
+	int l, pos;
+
+	if (io->error)
+		return (-1);
+	if (io->eof)
+		return (0);
+
+	for (pos = 0; len > 0; pos += l, len -= l) {
+		/* empty buffer */
+		if (!io->buf || io->bufpos == io->buflen)
+			if (_http_fillbuf(io, len) < 1)
+				break;
+		l = io->buflen - io->bufpos;
+		if (len < l)
+			l = len;
+		bcopy(io->buf + io->bufpos, buf + pos, l);
+		io->bufpos += l;
+	}
+
+	if (!pos && io->error)
+		return (-1);
+	return (pos);
+}
+
+/*
+ * Write function
+ */
+static int
+_http_writefn(void *v, const char *buf, int len)
+{
+	struct httpio *io = (struct httpio *)v;
+
+	return (_fetch_write(io->conn, buf, len));
+}
+
+/*
+ * Close function
+ */
+static int
+_http_closefn(void *v)
+{
+	struct httpio *io = (struct httpio *)v;
+	int r;
+
+	r = _fetch_close(io->conn);
+	if (io->buf)
+		free(io->buf);
+	free(io);
+	return (r);
+}
+
+/*
+ * Wrap a file descriptor up
+ */
+static FILE *
+_http_funopen(conn_t *conn, int chunked)
+{
+	struct httpio *io;
+	FILE *f;
+
+	if ((io = calloc(1, sizeof(*io))) == NULL) {
+		_fetch_syserr();
+		return (NULL);
+	}
+	io->conn = conn;
+	io->chunked = chunked;
+    cookie_io_functions_t cookie;
+    cookie.read = (cookie_read_function_t *)_http_readfn;
+    cookie.write = (cookie_write_function_t *)_http_writefn;
+    cookie.seek = (cookie_seek_function_t *)NULL;
+    cookie.close = (cookie_close_function_t *)_http_closefn;
+    f = fopencookie(io, "rw", cookie);
+	if (f == NULL) {
+		_fetch_syserr();
+		free(io);
+		return (NULL);
+	}
+	return (f);
+}
+
+
+/*****************************************************************************
+ * Helper functions for talking to the server and parsing its replies
+ */
+
+/* Header types */
+typedef enum {
+	hdr_syserror = -2,
+	hdr_error = -1,
+	hdr_end = 0,
+	hdr_unknown = 1,
+	hdr_content_length,
+	hdr_content_range,
+	hdr_last_modified,
+	hdr_location,
+	hdr_transfer_encoding,
+	hdr_www_authenticate
+} hdr_t;
+
+/* Names of interesting headers */
+static struct {
+	hdr_t		 num;
+	const char	*name;
+} hdr_names[] = {
+    { hdr_content_length,		"Content-Length" },
+    { hdr_content_range,		"Content-Range" },
+    { hdr_last_modified,		"Last-Modified" },
+    { hdr_location,			    "Location" },
+    { hdr_transfer_encoding,	"Transfer-Encoding" },
+    { hdr_www_authenticate,		"WWW-Authenticate" },
+    { hdr_unknown,			    NULL },
+};
+
+/*
+ * Send a formatted line; optionally echo to terminal
+ */
+static int
+_http_cmd(conn_t *conn, const char *fmt, ...)
+{
+	va_list ap;
+	size_t len;
+	char *msg;
+	int r;
+
+	va_start(ap, fmt);
+	len = vasprintf(&msg, fmt, ap);
+	va_end(ap);
+
+	if (msg == NULL) {
+		errno = ENOMEM;
+		_fetch_syserr();
+		return (-1);
+	}
+
+	r = _fetch_putln(conn, msg, len);
+	free(msg);
+
+	if (r == -1) {
+		_fetch_syserr();
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Get and parse status line
+ */
+static int
+_http_get_reply(conn_t *conn)
+{
+	char *p;
+
+	if (_fetch_getln(conn) == -1)
+		return (-1);
+	/*
+	 * A valid status line looks like "HTTP/m.n xyz reason" where m
+	 * and n are the major and minor protocol version numbers and xyz
+	 * is the reply code.
+	 * Unfortunately, there are servers out there (NCSA 1.5.1, to name
+	 * just one) that do not send a version number, so we can't rely
+	 * on finding one, but if we do, insist on it being 1.0 or 1.1.
+	 * We don't care about the reason phrase.
+	 */
+	if (strncmp(conn->buf, "HTTP", 4) != 0)
+		return (HTTP_PROTOCOL_ERROR);
+	p = conn->buf + 4;
+	if (*p == '/') {
+		if (p[1] != '1' || p[2] != '.' || (p[3] != '0' && p[3] != '1'))
+			return (HTTP_PROTOCOL_ERROR);
+		p += 4;
+	}
+	if (*p != ' ' || !isdigit(p[1]) || !isdigit(p[2]) || !isdigit(p[3]))
+		return (HTTP_PROTOCOL_ERROR);
+
+	conn->err = (p[1] - '0') * 100 + (p[2] - '0') * 10 + (p[3] - '0');
+	return (conn->err);
+}
+
+/*
+ * Check a header; if the type matches the given string, return a pointer
+ * to the beginning of the value.
+ */
+static const char *
+_http_match(const char *str, const char *hdr)
+{
+	while (*str && *hdr && tolower(*str++) == tolower(*hdr++))
+		/* nothing */;
+	if (*str || *hdr != ':')
+		return (NULL);
+	while (*hdr && isspace(*++hdr))
+		/* nothing */;
+	return (hdr);
+}
+
+/*
+ * Get the next header and return the appropriate symbolic code.
+ */
+static hdr_t
+_http_next_header(conn_t *conn, const char **p)
+{
+	int i;
+
+	if (_fetch_getln(conn) == -1)
+		return (hdr_syserror);
+	while (conn->buflen && isspace(conn->buf[conn->buflen - 1]))
+		conn->buflen--;
+	conn->buf[conn->buflen] = '\0';
+	if (conn->buflen == 0)
+		return (hdr_end);
+	/*
+	 * We could check for malformed headers but we don't really care.
+	 * A valid header starts with a token immediately followed by a
+	 * colon; a token is any sequence of non-control, non-whitespace
+	 * characters except "()<>@,;:\\\"{}".
+	 */
+	for (i = 0; hdr_names[i].num != hdr_unknown; i++)
+		if ((*p = _http_match(hdr_names[i].name, conn->buf)) != NULL)
+			return (hdr_names[i].num);
+	return (hdr_unknown);
+}
+
+/*
+ * Parse a last-modified header
+ */
+static int
+_http_parse_mtime(const char *p, time_t *mtime)
+{
+	char locale[64], *r;
+	struct tm tm;
+
+	strncpy(locale, setlocale(LC_TIME, NULL), sizeof(locale));
+	setlocale(LC_TIME, "C");
+	r = (char *)strptime(p, "%a, %d %b %Y %H:%M:%S GMT", &tm);
+	/* XXX should add support for date-2 and date-3 */
+	setlocale(LC_TIME, locale);
+	if (r == NULL)
+		return (-1);
+	DEBUG(fprintf(stderr, "last modified: [%04d-%02d-%02d "
+		  "%02d:%02d:%02d]\n",
+		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+		  tm.tm_hour, tm.tm_min, tm.tm_sec));
+	*mtime = timegm(&tm);
+	return (0);
+}
+
+/*
+ * Parse a content-length header
+ */
+static int
+_http_parse_length(const char *p, off_t *length)
+{
+	off_t len;
+
+	for (len = 0; *p && isdigit(*p); ++p)
+		len = len * 10 + (*p - '0');
+	if (*p)
+		return (-1);
+	DEBUG(fprintf(stderr, "content length: [%lld]\n",
+	    (long long)len));
+	*length = len;
+	return (0);
+}
+
+/*
+ * Parse a content-range header
+ */
+static int
+_http_parse_range(const char *p, off_t *offset, off_t *length, off_t *size)
+{
+	off_t first, last, len;
+
+	if (strncasecmp(p, "bytes ", 6) != 0)
+		return (-1);
+	p += 6;
+	if (*p == '*') {
+		first = last = -1;
+		++p;
+	} else {
+		for (first = 0; *p && isdigit(*p); ++p)
+			first = first * 10 + *p - '0';
+		if (*p != '-')
+			return (-1);
+		for (last = 0, ++p; *p && isdigit(*p); ++p)
+			last = last * 10 + *p - '0';
+	}
+	if (first > last || *p != '/')
+		return (-1);
+	for (len = 0, ++p; *p && isdigit(*p); ++p)
+		len = len * 10 + *p - '0';
+	if (*p || len < last - first + 1)
+		return (-1);
+	if (first == -1) {
+		DEBUG(fprintf(stderr, "content range: [*/%lld]\n",
+		    (long long)len));
+		*length = 0;
+	} else {
+		DEBUG(fprintf(stderr, "content range: [%lld-%lld/%lld]\n",
+		    (long long)first, (long long)last, (long long)len));
+		*length = last - first + 1;
+	}
+	*offset = first;
+	*size = len;
+	return (0);
+}
+
+
+/*****************************************************************************
+ * Helper functions for authorization
+ */
+
+/*
+ * Base64 encoding
+ */
+static char *
+_http_base64(const char *src)
+{
+	static const char base64[] =
+	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	    "abcdefghijklmnopqrstuvwxyz"
+	    "0123456789+/";
+	char *str, *dst;
+	size_t l;
+	int t, r;
+
+	l = strlen(src);
+	if ((str = malloc(((l + 2) / 3) * 4 + 1)) == NULL)
+		return (NULL);
+	dst = str;
+	r = 0;
+
+	while (l >= 3) {
+		t = (src[0] << 16) | (src[1] << 8) | src[2];
+		dst[0] = base64[(t >> 18) & 0x3f];
+		dst[1] = base64[(t >> 12) & 0x3f];
+		dst[2] = base64[(t >> 6) & 0x3f];
+		dst[3] = base64[(t >> 0) & 0x3f];
+		src += 3; l -= 3;
+		dst += 4; r += 4;
+	}
+
+	switch (l) {
+	case 2:
+		t = (src[0] << 16) | (src[1] << 8);
+		dst[0] = base64[(t >> 18) & 0x3f];
+		dst[1] = base64[(t >> 12) & 0x3f];
+		dst[2] = base64[(t >> 6) & 0x3f];
+		dst[3] = '=';
+		dst += 4;
+		r += 4;
+		break;
+	case 1:
+		t = src[0] << 16;
+		dst[0] = base64[(t >> 18) & 0x3f];
+		dst[1] = base64[(t >> 12) & 0x3f];
+		dst[2] = dst[3] = '=';
+		dst += 4;
+		r += 4;
+		break;
+	case 0:
+		break;
+	}
+
+	*dst = 0;
+	return (str);
+}
+
+/*
+ * Encode username and password
+ */
+static int
+_http_basic_auth(conn_t *conn, const char *hdr, const char *usr, const char *pwd)
+{
+	char *upw, *auth;
+	int r;
+
+	DEBUG(fprintf(stderr, "usr: [%s]\n", usr));
+	DEBUG(fprintf(stderr, "pwd: [%s]\n", pwd));
+	if (asprintf(&upw, "%s:%s", usr, pwd) == -1)
+		return (-1);
+	auth = _http_base64(upw);
+	free(upw);
+	if (auth == NULL)
+		return (-1);
+	r = _http_cmd(conn, "%s: Basic %s", hdr, auth);
+	free(auth);
+	return (r);
+}
+
+/*
+ * Send an authorization header
+ */
+static int
+_http_authorize(conn_t *conn, const char *hdr, const char *p)
+{
+	/* basic authorization */
+	if (strncasecmp(p, "basic:", 6) == 0) {
+		char *user, *pwd, *str;
+		int r;
+
+		/* skip realm */
+		for (p += 6; *p && *p != ':'; ++p)
+			/* nothing */ ;
+		if (!*p || strchr(++p, ':') == NULL)
+			return (-1);
+		if ((str = strdup(p)) == NULL)
+			return (-1); /* XXX */
+		user = str;
+		pwd = strchr(str, ':');
+		*pwd++ = '\0';
+		r = _http_basic_auth(conn, hdr, user, pwd);
+		free(str);
+		return (r);
+	}
+	return (-1);
+}
+
+
+/*****************************************************************************
+ * Helper functions for connecting to a server or proxy
+ */
+
+/*
+ * Connect to the correct HTTP server or proxy.
+ */
+static conn_t *
+_http_connect(struct url *URL, struct url *purl, const char *flags)
+{
+	conn_t *conn;
+	int verbose;
+	int af;
+
+#ifdef INET6
+	af = AF_UNSPEC;
+#else
+	af = AF_INET;
+#endif
+
+	verbose = CHECK_FLAG('v');
+	if (CHECK_FLAG('4'))
+		af = AF_INET;
+#ifdef INET6
+	else if (CHECK_FLAG('6'))
+		af = AF_INET6;
+#endif
+
+	if (purl && strcasecmp(URL->scheme, SCHEME_HTTPS) != 0) {
+		URL = purl;
+	} else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0) {
+		/* can't talk http to an ftp server */
+		/* XXX should set an error code */
+		return (NULL);
+	}
+
+	if ((conn = _fetch_connect(URL->host, URL->port, af, verbose)) == NULL)
+		/* _fetch_connect() has already set an error code */
+		return (NULL);
+	if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0 &&
+	    _fetch_ssl(conn, verbose) == -1) {
+		_fetch_close(conn);
+		/* grrr */
+		_fetch_syserr();
+		return (NULL);
+	}
+
+#ifdef TCP_NOPUSH
+	int val = 1;
+	setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val, sizeof(val));
+#endif
+
+	return (conn);
+}
+
+static struct url *
+_http_get_proxy(const char *flags)
+{
+	struct url *purl;
+	char *p;
+
+	if (flags != NULL && strchr(flags, 'd') != NULL)
+		return (NULL);
+	if (((p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
+	    *p && (purl = fetchParseURL(p))) {
+		if (!*purl->scheme)
+			strcpy(purl->scheme, SCHEME_HTTP);
+		if (!purl->port)
+			purl->port = _fetch_default_proxy_port(purl->scheme);
+		if (strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
+			return (purl);
+		fetchFreeURL(purl);
+	}
+	return (NULL);
+}
+
+static void
+_http_print_html(FILE *out, FILE *in)
+{
+	size_t len;
+    unsigned int sz = 1024;
+	char *line, *p, *q;
+	int comment, tag;
+
+    line = (char *)calloc(1024, sizeof(char));
+	comment = tag = 0;
+	while ((len = getline(&line, &sz, in)) > 0) {
+		while (len && isspace(line[len - 1]))
+			--len;
+		for (p = q = line; q < line + len; ++q) {
+			if (comment && *q == '-') {
+				if (q + 2 < line + len &&
+				    strcmp(q, "-->") == 0) {
+					tag = comment = 0;
+					q += 2;
+				}
+			} else if (tag && !comment && *q == '>') {
+				p = q + 1;
+				tag = 0;
+			} else if (!tag && *q == '<') {
+				if (q > p)
+					fwrite(p, q - p, 1, out);
+				tag = 1;
+				if (q + 3 < line + len &&
+				    strcmp(q, "<!--") == 0) {
+					comment = 1;
+					q += 3;
+				}
+			}
+		}
+		if (!tag && q > p)
+			fwrite(p, q - p, 1, out);
+		fputc('\n', out);
+	}
+}
+
+
+/*****************************************************************************
+ * Core
+ */
+
+/*
+ * Send a request and process the reply
+ *
+ * XXX This function is way too long, the do..while loop should be split
+ * XXX off into a separate function.
+ */
+FILE *
+_http_request(struct url *URL, const char *op, struct url_stat *us,
+    struct url *purl, const char *flags)
+{
+	conn_t *conn;
+	struct url *url, *new;
+	int chunked, direct, need_auth, noredirect, verbose;
+	int e, i, n, val;
+	off_t offset, clength, length, size;
+	time_t mtime;
+	const char *p;
+	FILE *f;
+	hdr_t h;
+	char hbuf[MAXHOSTNAMELEN + 7], *host;
+
+	direct = CHECK_FLAG('d');
+	noredirect = CHECK_FLAG('A');
+	verbose = CHECK_FLAG('v');
+
+	if (direct && purl) {
+		fetchFreeURL(purl);
+		purl = NULL;
+	}
+
+	/* try the provided URL first */
+	url = URL;
+
+	/* if the A flag is set, we only get one try */
+	n = noredirect ? 1 : MAX_REDIRECT;
+	i = 0;
+
+	e = HTTP_PROTOCOL_ERROR;
+	need_auth = 0;
+	do {
+		new = NULL;
+		chunked = 0;
+		offset = 0;
+		clength = -1;
+		length = -1;
+		size = -1;
+		mtime = 0;
+
+		/* check port */
+		if (!url->port)
+			url->port = _fetch_default_port(url->scheme);
+
+		/* were we redirected to an FTP URL? */
+		if (purl == NULL && strcmp(url->scheme, SCHEME_FTP) == 0) {
+			if (strcmp(op, "GET") == 0)
+				return (_ftp_request(url, "RETR", us, purl, flags));
+			else if (strcmp(op, "HEAD") == 0)
+				return (_ftp_request(url, "STAT", us, purl, flags));
+		}
+
+		/* connect to server or proxy */
+		if ((conn = _http_connect(url, purl, flags)) == NULL)
+			goto ouch;
+
+		host = url->host;
+#ifdef INET6
+		if (strchr(url->host, ':')) {
+			snprintf(hbuf, sizeof(hbuf), "[%s]", url->host);
+			host = hbuf;
+		}
+#endif
+		if (url->port != _fetch_default_port(url->scheme)) {
+			if (host != hbuf) {
+				strcpy(hbuf, host);
+				host = hbuf;
+			}
+			snprintf(hbuf + strlen(hbuf),
+			    sizeof(hbuf) - strlen(hbuf), ":%d", url->port);
+		}
+
+		/* send request */
+		if (verbose)
+			_fetch_info("requesting %s://%s%s",
+			    url->scheme, host, url->doc);
+		if (purl) {
+			_http_cmd(conn, "%s %s://%s%s HTTP/1.1",
+			    op, url->scheme, host, url->doc);
+		} else {
+			_http_cmd(conn, "%s %s HTTP/1.1",
+			    op, url->doc);
+		}
+
+		/* virtual host */
+		_http_cmd(conn, "Host: %s", host);
+
+		/* proxy authorization */
+		if (purl) {
+			if (*purl->user || *purl->pwd)
+				_http_basic_auth(conn, "Proxy-Authorization",
+				    purl->user, purl->pwd);
+			else if ((p = getenv("HTTP_PROXY_AUTH")) != NULL && *p != '\0')
+				_http_authorize(conn, "Proxy-Authorization", p);
+		}
+
+		/* server authorization */
+		if (need_auth || *url->user || *url->pwd) {
+			if (*url->user || *url->pwd)
+				_http_basic_auth(conn, "Authorization", url->user, url->pwd);
+			else if ((p = getenv("HTTP_AUTH")) != NULL && *p != '\0')
+				_http_authorize(conn, "Authorization", p);
+			else if (fetchAuthMethod && fetchAuthMethod(url) == 0) {
+				_http_basic_auth(conn, "Authorization", url->user, url->pwd);
+			} else {
+				_http_seterr(HTTP_NEED_AUTH);
+				goto ouch;
+			}
+		}
+
+		/* other headers */
+		if ((p = getenv("HTTP_REFERER")) != NULL && *p != '\0') {
+			if (strcasecmp(p, "auto") == 0)
+				_http_cmd(conn, "Referer: %s://%s%s",
+				    url->scheme, host, url->doc);
+			else
+				_http_cmd(conn, "Referer: %s", p);
+		}
+		if ((p = getenv("HTTP_USER_AGENT")) != NULL && *p != '\0')
+			_http_cmd(conn, "User-Agent: %s", p);
+		else
+			_http_cmd(conn, "User-Agent: " _LIBFETCH_VER);
+		if (url->offset > 0)
+			_http_cmd(conn, "Range: bytes=%lld-", (long long)url->offset);
+		_http_cmd(conn, "Connection: close");
+		_http_cmd(conn, "");
+
+		/*
+		 * Force the queued request to be dispatched.  Normally, one
+		 * would do this with shutdown(2) but squid proxies can be
+		 * configured to disallow such half-closed connections.  To
+		 * be compatible with such configurations, fiddle with socket
+		 * options to force the pending data to be written.
+		 */
+#ifdef TCP_NOPUSH
+		val = 0;
+		setsockopt(conn->sd, IPPROTO_TCP, TCP_NOPUSH, &val,
+			   sizeof(val));
+#endif
+		val = 1;
+		setsockopt(conn->sd, IPPROTO_TCP, TCP_NODELAY, &val,
+			   sizeof(val));
+
+		/* get reply */
+		switch (_http_get_reply(conn)) {
+		case HTTP_OK:
+		case HTTP_PARTIAL:
+			/* fine */
+			break;
+		case HTTP_MOVED_PERM:
+		case HTTP_MOVED_TEMP:
+		case HTTP_SEE_OTHER:
+			/*
+			 * Not so fine, but we still have to read the
+			 * headers to get the new location.
+			 */
+			break;
+		case HTTP_NEED_AUTH:
+			if (need_auth) {
+				/*
+				 * We already sent out authorization code,
+				 * so there's nothing more we can do.
+				 */
+				_http_seterr(conn->err);
+				goto ouch;
+			}
+			/* try again, but send the password this time */
+			if (verbose)
+				_fetch_info("server requires authorization");
+			break;
+		case HTTP_NEED_PROXY_AUTH:
+			/*
+			 * If we're talking to a proxy, we already sent
+			 * our proxy authorization code, so there's
+			 * nothing more we can do.
+			 */
+			_http_seterr(conn->err);
+			goto ouch;
+		case HTTP_BAD_RANGE:
+			/*
+			 * This can happen if we ask for 0 bytes because
+			 * we already have the whole file.  Consider this
+			 * a success for now, and check sizes later.
+			 */
+			break;
+		case HTTP_PROTOCOL_ERROR:
+			/* fall through */
+		case -1:
+			_fetch_syserr();
+			goto ouch;
+		default:
+			_http_seterr(conn->err);
+            goto ouch;
+			/* fall through so we can get the full error message */
+		}
+
+		/* get headers */
+		do {
+			switch ((h = _http_next_header(conn, &p))) {
+			case hdr_syserror:
+				_fetch_syserr();
+				goto ouch;
+			case hdr_error:
+				_http_seterr(HTTP_PROTOCOL_ERROR);
+				goto ouch;
+			case hdr_content_length:
+				_http_parse_length(p, &clength);
+				break;
+			case hdr_content_range:
+				_http_parse_range(p, &offset, &length, &size);
+				break;
+			case hdr_last_modified:
+				_http_parse_mtime(p, &mtime);
+				break;
+			case hdr_location:
+				if (!HTTP_REDIRECT(conn->err))
+					break;
+				if (new)
+					free(new);
+				if (verbose)
+					_fetch_info("%d redirect to %s", conn->err, p);
+				if (*p == '/')
+					/* absolute path */
+					new = fetchMakeURL(url->scheme, url->host, url->port, p,
+					    url->user, url->pwd);
+				else
+					new = fetchParseURL(p);
+				if (new == NULL) {
+					/* XXX should set an error code */
+					DEBUG(fprintf(stderr, "failed to parse new URL\n"));
+					goto ouch;
+				}
+				if (!*new->user && !*new->pwd) {
+					strcpy(new->user, url->user);
+					strcpy(new->pwd, url->pwd);
+				}
+				new->offset = url->offset;
+				new->length = url->length;
+				break;
+			case hdr_transfer_encoding:
+				/* XXX weak test*/
+				chunked = (strcasecmp(p, "chunked") == 0);
+				break;
+			case hdr_www_authenticate:
+				if (conn->err != HTTP_NEED_AUTH)
+					break;
+				/* if we were smarter, we'd check the method and realm */
+				break;
+			case hdr_end:
+				/* fall through */
+			case hdr_unknown:
+				/* ignore */
+				break;
+			}
+		} while (h > hdr_end);
+
+		/* we need to provide authentication */
+		if (conn->err == HTTP_NEED_AUTH) {
+			e = conn->err;
+			need_auth = 1;
+			_fetch_close(conn);
+			conn = NULL;
+			continue;
+		}
+
+		/* requested range not satisfiable */
+		if (conn->err == HTTP_BAD_RANGE) {
+			if (url->offset == size && url->length == 0) {
+				/* asked for 0 bytes; fake it */
+				offset = url->offset;
+				conn->err = HTTP_OK;
+				break;
+			} else {
+				_http_seterr(conn->err);
+				goto ouch;
+			}
+		}
+
+		/* we have a hit or an error */
+		if (conn->err == HTTP_OK || conn->err == HTTP_PARTIAL || HTTP_ERROR(conn->err))
+			break;
+
+		/* all other cases: we got a redirect */
+		e = conn->err;
+		need_auth = 0;
+		_fetch_close(conn);
+		conn = NULL;
+		if (!new) {
+			DEBUG(fprintf(stderr, "redirect with no new location\n"));
+			break;
+		}
+		if (url != URL)
+			fetchFreeURL(url);
+		url = new;
+	} while (++i < n);
+
+	/* we failed, or ran out of retries */
+	if (conn == NULL) {
+		_http_seterr(e);
+		goto ouch;
+	}
+
+	DEBUG(fprintf(stderr, "offset %lld, length %lld,"
+		  " size %lld, clength %lld\n",
+		  (long long)offset, (long long)length,
+		  (long long)size, (long long)clength));
+
+	/* check for inconsistencies */
+	if (clength != -1 && length != -1 && clength != length) {
+		_http_seterr(HTTP_PROTOCOL_ERROR);
+		goto ouch;
+	}
+	if (clength == -1)
+		clength = length;
+	if (clength != -1)
+		length = offset + clength;
+	if (length != -1 && size != -1 && length != size) {
+		_http_seterr(HTTP_PROTOCOL_ERROR);
+		goto ouch;
+	}
+	if (size == -1)
+		size = length;
+
+	/* fill in stats */
+	if (us) {
+		us->size = size;
+		us->atime = us->mtime = mtime;
+	}
+
+	/* too far? */
+	if (URL->offset > 0 && offset > URL->offset) {
+		_http_seterr(HTTP_PROTOCOL_ERROR);
+		goto ouch;
+	}
+
+	/* report back real offset and size */
+	URL->offset = offset;
+	URL->length = clength;
+
+	/* wrap it up in a FILE */
+	if ((f = _http_funopen(conn, chunked)) == NULL) {
+		_fetch_syserr();
+		goto ouch;
+	}
+
+	if (url != URL)
+		fetchFreeURL(url);
+	if (purl)
+		fetchFreeURL(purl);
+
+	if (HTTP_ERROR(conn->err)) {
+		_http_print_html(stderr, f);
+		fclose(f);
+		f = NULL;
+	}
+
+	return (f);
+
+ouch:
+	if (url != URL)
+		fetchFreeURL(url);
+	if (purl)
+		fetchFreeURL(purl);
+	if (conn != NULL)
+		_fetch_close(conn);
+	return (NULL);
+}
+
+
+/*****************************************************************************
+ * Entry points
+ */
+
+/*
+ * Retrieve and stat a file by HTTP
+ */
+FILE *
+fetchXGetHTTP(struct url *URL, struct url_stat *us, const char *flags)
+{
+	return (_http_request(URL, "GET", us, _http_get_proxy(flags), flags));
+}
+
+/*
+ * Retrieve a file by HTTP
+ */
+FILE *
+fetchGetHTTP(struct url *URL, const char *flags)
+{
+	return (fetchXGetHTTP(URL, NULL, flags));
+}
+
+/*
+ * Store a file by HTTP
+ */
+FILE *
+fetchPutHTTP(struct url *URL, const char *flags)
+{
+	warnx("fetchPutHTTP(): not implemented");
+	return (NULL);
+}
+
+/*
+ * Get an HTTP document's metadata
+ */
+int
+fetchStatHTTP(struct url *URL, struct url_stat *us, const char *flags)
+{
+	FILE *f;
+
+	f = _http_request(URL, "HEAD", us, _http_get_proxy(flags), flags);
+	if (f == NULL)
+		return (-1);
+	fclose(f);
+	return (0);
+}
+
+/*
+ * List a directory
+ */
+struct url_ent *
+fetchListHTTP(struct url *url, const char *flags)
+{
+	warnx("fetchListHTTP(): not implemented");
+	return (NULL);
+}