/* Copyright 1999-2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* Utility routines for Apache proxy */
#include "mod_proxy.h"


static int proxy_match_ipaddr(struct dirconn_entry *This, request_rec *r);
static int proxy_match_domainname(struct dirconn_entry *This, request_rec *r);
static int proxy_match_hostname(struct dirconn_entry *This, request_rec *r);
static int proxy_match_word(struct dirconn_entry *This, request_rec *r);

APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL(proxy, PROXY, int, create_req, 
                                   (request_rec *r, request_rec *pr), (r, pr),
                                   OK, DECLINED)

/* already called in the knowledge that the characters are hex digits */
PROXY_DECLARE(int) ap_proxy_hex2c(const char *x)
{
    int i, ch;

#if !APR_CHARSET_EBCDIC
    ch = x[0];
    if (apr_isdigit(ch))
	i = ch - '0';
    else if (apr_isupper(ch))
	i = ch - ('A' - 10);
    else
	i = ch - ('a' - 10);
    i <<= 4;

    ch = x[1];
    if (apr_isdigit(ch))
	i += ch - '0';
    else if (apr_isupper(ch))
	i += ch - ('A' - 10);
    else
	i += ch - ('a' - 10);
    return i;
#else /*APR_CHARSET_EBCDIC*/
    /* we assume that the hex value refers to an ASCII character
     * so convert to EBCDIC so that it makes sense locally;
     *
     * example:
     *
     * client specifies %20 in URL to refer to a space char;
     * at this point we're called with EBCDIC "20"; after turning
     * EBCDIC "20" into binary 0x20, we then need to assume that 0x20
     * represents an ASCII char and convert 0x20 to EBCDIC, yielding
     * 0x40
     */
    char buf[1];

    if (1 == sscanf(x, "%2x", &i)) {
        buf[0] = i & 0xFF;
        ap_xlate_proto_from_ascii(buf, 1);
        return buf[0];
    }
    else {
        return 0;
    }
#endif /*APR_CHARSET_EBCDIC*/
}

PROXY_DECLARE(void) ap_proxy_c2hex(int ch, char *x)
{
#if !APR_CHARSET_EBCDIC
    int i;

    x[0] = '%';
    i = (ch & 0xF0) >> 4;
    if (i >= 10)
	x[1] = ('A' - 10) + i;
    else
	x[1] = '0' + i;

    i = ch & 0x0F;
    if (i >= 10)
	x[2] = ('A' - 10) + i;
    else
	x[2] = '0' + i;
#else /*APR_CHARSET_EBCDIC*/
    static const char ntoa[] = { "0123456789ABCDEF" };
    char buf[1];

    ch &= 0xFF;

    buf[0] = ch;
    ap_xlate_proto_to_ascii(buf, 1);

    x[0] = '%';
    x[1] = ntoa[(buf[0] >> 4) & 0x0F];
    x[2] = ntoa[buf[0] & 0x0F];
    x[3] = '\0';
#endif /*APR_CHARSET_EBCDIC*/
}

/*
 * canonicalise a URL-encoded string
 */

/*
 * Convert a URL-encoded string to canonical form.
 * It decodes characters which need not be encoded,
 * and encodes those which must be encoded, and does not touch
 * those which must not be touched.
 */
PROXY_DECLARE(char *)ap_proxy_canonenc(apr_pool_t *p, const char *x, int len, enum enctype t,
	int isenc)
{
    int i, j, ch;
    char *y;
    char *allowed;	/* characters which should not be encoded */
    char *reserved;	/* characters which much not be en/de-coded */

/* N.B. in addition to :@&=, this allows ';' in an http path
 * and '?' in an ftp path -- this may be revised
 * 
 * Also, it makes a '+' character in a search string reserved, as
 * it may be form-encoded. (Although RFC 1738 doesn't allow this -
 * it only permits ; / ? : @ = & as reserved chars.)
 */
    if (t == enc_path)
	allowed = "$-_.+!*'(),;:@&=";
    else if (t == enc_search)
	allowed = "$-_.!*'(),;:@&=";
    else if (t == enc_user)
	allowed = "$-_.+!*'(),;@&=";
    else if (t == enc_fpath)
	allowed = "$-_.+!*'(),?:@&=";
    else			/* if (t == enc_parm) */
	allowed = "$-_.+!*'(),?/:@&=";

    if (t == enc_path)
	reserved = "/";
    else if (t == enc_search)
	reserved = "+";
    else
	reserved = "";

    y = apr_palloc(p, 3 * len + 1);

    for (i = 0, j = 0; i < len; i++, j++) {
/* always handle '/' first */
	ch = x[i];
	if (strchr(reserved, ch)) {
	    y[j] = ch;
	    continue;
	}
/* decode it if not already done */
	if (isenc && ch == '%') {
	    if (!apr_isxdigit(x[i + 1]) || !apr_isxdigit(x[i + 2]))
		return NULL;
	    ch = ap_proxy_hex2c(&x[i + 1]);
	    i += 2;
	    if (ch != 0 && strchr(reserved, ch)) {	/* keep it encoded */
		ap_proxy_c2hex(ch, &y[j]);
		j += 2;
		continue;
	    }
	}
/* recode it, if necessary */
	if (!apr_isalnum(ch) && !strchr(allowed, ch)) {
	    ap_proxy_c2hex(ch, &y[j]);
	    j += 2;
	}
	else
	    y[j] = ch;
    }
    y[j] = '\0';
    return y;
}

/*
 * Parses network-location.
 *    urlp           on input the URL; on output the path, after the leading /
 *    user           NULL if no user/password permitted
 *    password       holder for password
 *    host           holder for host
 *    port           port number; only set if one is supplied.
 *
 * Returns an error string.
 */
PROXY_DECLARE(char *)
     ap_proxy_canon_netloc(apr_pool_t *p, char **const urlp, char **userp,
			char **passwordp, char **hostp, apr_port_t *port)
{
    char *addr, *scope_id, *strp, *host, *url = *urlp;
    char *user = NULL, *password = NULL;
    apr_port_t tmp_port;
    apr_status_t rv;

    if (url[0] != '/' || url[1] != '/')
	return "Malformed URL";
    host = url + 2;
    url = strchr(host, '/');
    if (url == NULL)
	url = "";
    else
	*(url++) = '\0';	/* skip seperating '/' */

    /* find _last_ '@' since it might occur in user/password part */
    strp = strrchr(host, '@');

    if (strp != NULL) {
	*strp = '\0';
	user = host;
	host = strp + 1;

/* find password */
	strp = strchr(user, ':');
	if (strp != NULL) {
	    *strp = '\0';
	    password = ap_proxy_canonenc(p, strp + 1, strlen(strp + 1), enc_user, 1);
	    if (password == NULL)
		return "Bad %-escape in URL (password)";
	}

	user = ap_proxy_canonenc(p, user, strlen(user), enc_user, 1);
	if (user == NULL)
	    return "Bad %-escape in URL (username)";
    }
    if (userp != NULL) {
	*userp = user;
    }
    if (passwordp != NULL) {
	*passwordp = password;
    }

    /* Parse the host string to separate host portion from optional port.
     * Perform range checking on port.
     */
    rv = apr_parse_addr_port(&addr, &scope_id, &tmp_port, host, p);
    if (rv != APR_SUCCESS || addr == NULL || scope_id != NULL) {
        return "Invalid host/port";
    }
    if (tmp_port != 0) { /* only update caller's port if port was specified */
        *port = tmp_port;
    }

    ap_str_tolower(addr); /* DNS names are case-insensitive */

    *urlp = url;
    *hostp = addr;

    return NULL;
}

static const char * const lwday[7] =
{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

/*
 * If the date is a valid RFC 850 date or asctime() date, then it
 * is converted to the RFC 1123 format, otherwise it is not modified.
 * This routine is not very fast at doing conversions, as it uses
 * sscanf and sprintf. However, if the date is already correctly
 * formatted, then it exits very quickly.
 */
PROXY_DECLARE(const char *)
     ap_proxy_date_canon(apr_pool_t *p, const char *x1)
{
    char *x = apr_pstrdup(p, x1);
    int wk, mday, year, hour, min, sec, mon;
    char *q, month[4], zone[4], week[4];

    q = strchr(x, ',');
    /* check for RFC 850 date */
    if (q != NULL && q - x > 3 && q[1] == ' ') {
	*q = '\0';
	for (wk = 0; wk < 7; wk++)
	    if (strcmp(x, lwday[wk]) == 0)
		break;
	*q = ',';
	if (wk == 7)
	    return x;		/* not a valid date */
	if (q[4] != '-' || q[8] != '-' || q[11] != ' ' || q[14] != ':' ||
	    q[17] != ':' || strcmp(&q[20], " GMT") != 0)
	    return x;
	if (sscanf(q + 2, "%u-%3s-%u %u:%u:%u %3s", &mday, month, &year,
		   &hour, &min, &sec, zone) != 7)
	    return x;
	if (year < 70)
	    year += 2000;
	else
	    year += 1900;
    }
    else {
/* check for acstime() date */
	if (x[3] != ' ' || x[7] != ' ' || x[10] != ' ' || x[13] != ':' ||
	    x[16] != ':' || x[19] != ' ' || x[24] != '\0')
	    return x;
	if (sscanf(x, "%3s %3s %u %u:%u:%u %u", week, month, &mday, &hour,
		   &min, &sec, &year) != 7)
	    return x;
	for (wk = 0; wk < 7; wk++)
	    if (strcmp(week, apr_day_snames[wk]) == 0)
		break;
	if (wk == 7)
	    return x;
    }

/* check date */
    for (mon = 0; mon < 12; mon++)
	if (strcmp(month, apr_month_snames[mon]) == 0)
	    break;
    if (mon == 12)
	return x;

    q = apr_palloc(p, 30);
    apr_snprintf(q, 30, "%s, %.2d %s %d %.2d:%.2d:%.2d GMT", apr_day_snames[wk],
       mday, apr_month_snames[mon], year, hour, min, sec);
    return q;
}

PROXY_DECLARE(request_rec *)ap_proxy_make_fake_req(conn_rec *c, request_rec *r)
{
    request_rec *rp = apr_pcalloc(c->pool, sizeof(*r));

    rp->pool            = c->pool;
    rp->status          = HTTP_OK;

    rp->headers_in      = apr_table_make(c->pool, 50);
    rp->subprocess_env  = apr_table_make(c->pool, 50);
    rp->headers_out     = apr_table_make(c->pool, 12);
    rp->err_headers_out = apr_table_make(c->pool, 5);
    rp->notes           = apr_table_make(c->pool, 5);

    rp->server = r->server;
    rp->proxyreq = r->proxyreq;
    rp->request_time = r->request_time;
    rp->connection      = c;
    rp->output_filters  = c->output_filters;
    rp->input_filters   = c->input_filters;
    rp->proto_output_filters  = c->output_filters;
    rp->proto_input_filters   = c->input_filters;

    rp->request_config  = ap_create_request_config(c->pool);
    proxy_run_create_req(r, rp);

    return rp;
}

/*
 * Reads headers from a buffer and returns an array of headers.
 * Returns NULL on file error
 * This routine tries to deal with too long lines and continuation lines.
 *
 * Note: Currently the headers are passed through unmerged. This has to be
 * done so that headers which react badly to merging (such as Set-Cookie
 * headers, which contain commas within the date field) do not get stuffed
 * up.
 */
PROXY_DECLARE(apr_table_t *)ap_proxy_read_headers(request_rec *r, request_rec *rr, char *buffer, int size, conn_rec *c)
{
    apr_table_t *headers_out;
    int len;
    char *value, *end;
    char field[MAX_STRING_LEN];
    int saw_headers = 0;
    void *sconf = r->server->module_config;
    proxy_server_conf *psc;

    psc = (proxy_server_conf *) ap_get_module_config(sconf, &proxy_module);

    headers_out = apr_table_make(r->pool, 20);

    /*
     * Read header lines until we get the empty separator line, a read error,
     * the connection closes (EOF), or we timeout.
     */
    while ((len = ap_getline(buffer, size, rr, 1)) > 0) {

	if (!(value = strchr(buffer, ':'))) {     /* Find the colon separator */

	    /* We may encounter invalid headers, usually from buggy
	     * MS IIS servers, so we need to determine just how to handle
	     * them. We can either ignore them, assume that they mark the
	     * start-of-body (eg: a missing CRLF) or (the default) mark
	     * the headers as totally bogus and return a 500. The sole
	     * exception is an extra "HTTP/1.0 200, OK" line sprinkled
	     * in between the usual MIME headers, which is a favorite
	     * IIS bug.
	     */
	     /* XXX: The mask check is buggy if we ever see an HTTP/1.10 */

	    if (!apr_date_checkmask(buffer, "HTTP/#.# ###*")) {
		if (psc->badopt == bad_error) {
		    /* Nope, it wasn't even an extra HTTP header. Give up. */
		    return NULL;
		}
		else if (psc->badopt == bad_body) {
		    /* if we've already started loading headers_out, then
		     * return what we've accumulated so far, in the hopes
		     * that they are useful. Otherwise, we completely bail.
		     */
		    /* FIXME: We've already scarfed the supposed 1st line of
		     * the body, so the actual content may end up being bogus
		     * as well. If the content is HTML, we may be lucky.
		     */
		    if (saw_headers) {
			ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
			 "proxy: Starting body due to bogus non-header in headers "
			 "returned by %s (%s)", r->uri, r->method);
			return headers_out;
		    } else {
			 ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
			 "proxy: No HTTP headers "
			 "returned by %s (%s)", r->uri, r->method);
			return NULL;
		    }
		}
	    }
	    /* this is the psc->badopt == bad_ignore case */
	    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
			 "proxy: Ignoring bogus HTTP header "
			 "returned by %s (%s)", r->uri, r->method);
	    continue;
	}

        *value = '\0';
        ++value;
	/* XXX: RFC2068 defines only SP and HT as whitespace, this test is
	 * wrong... and so are many others probably.
	 */
        while (apr_isspace(*value))
            ++value;            /* Skip to start of value   */

	/* should strip trailing whitespace as well */
	for (end = &value[strlen(value)-1]; end > value && apr_isspace(*end); --end)
	    *end = '\0';

        /* make sure we add so as not to destroy duplicated headers */
        apr_table_add(headers_out, buffer, value);
        saw_headers = 1;

	/* the header was too long; at the least we should skip extra data */
	if (len >= size - 1) { 
	    while ((len = ap_getline(field, MAX_STRING_LEN, rr, 1))
		    >= MAX_STRING_LEN - 1) {
		/* soak up the extra data */
	    }
	    if (len == 0) /* time to exit the larger loop as well */
		break;
	}
    }
    return headers_out;
}


/*
 * list is a comma-separated list of case-insensitive tokens, with
 * optional whitespace around the tokens.
 * The return returns 1 if the token val is found in the list, or 0
 * otherwise.
 */
PROXY_DECLARE(int) ap_proxy_liststr(const char *list, const char *val)
{
    int len, i;
    const char *p;

    len = strlen(val);

    while (list != NULL) {
	p = ap_strchr_c(list, ',');
	if (p != NULL) {
	    i = p - list;
	    do
		p++;
	    while (apr_isspace(*p));
	}
	else
	    i = strlen(list);

	while (i > 0 && apr_isspace(list[i - 1]))
	    i--;
	if (i == len && strncasecmp(list, val, len) == 0)
	    return 1;
	list = p;
    }
    return 0;
}

/*
 * list is a comma-separated list of case-insensitive tokens, with
 * optional whitespace around the tokens.
 * if val appears on the list of tokens, it is removed from the list,
 * and the new list is returned.
 */
PROXY_DECLARE(char *)ap_proxy_removestr(apr_pool_t *pool, const char *list, const char *val)
{
    int len, i;
    const char *p;
    char *new = NULL;

    len = strlen(val);

    while (list != NULL) {
	p = ap_strchr_c(list, ',');
	if (p != NULL) {
	    i = p - list;
	    do
		p++;
	    while (apr_isspace(*p));
	}
	else
	    i = strlen(list);

	while (i > 0 && apr_isspace(list[i - 1]))
	    i--;
	if (i == len && strncasecmp(list, val, len) == 0) {
	    /* do nothing */
	}
	else {
	    if (new)
		new = apr_pstrcat(pool, new, ",", apr_pstrndup(pool, list, i), NULL);
	    else
		new = apr_pstrndup(pool, list, i);
	}
	list = p;
    }
    return new;
}

/*
 * Converts 8 hex digits to a time integer
 */
PROXY_DECLARE(int) ap_proxy_hex2sec(const char *x)
{
    int i, ch;
    unsigned int j;

    for (i = 0, j = 0; i < 8; i++) {
	ch = x[i];
	j <<= 4;
	if (apr_isdigit(ch))
	    j |= ch - '0';
	else if (apr_isupper(ch))
	    j |= ch - ('A' - 10);
	else
	    j |= ch - ('a' - 10);
    }
    if (j == 0xffffffff)
	return -1;		/* so that it works with 8-byte ints */
    else
	return j;
}

/*
 * Converts a time integer to 8 hex digits
 */
PROXY_DECLARE(void) ap_proxy_sec2hex(int t, char *y)
{
    int i, ch;
    unsigned int j = t;

    for (i = 7; i >= 0; i--) {
	ch = j & 0xF;
	j >>= 4;
	if (ch >= 10)
	    y[i] = ch + ('A' - 10);
	else
	    y[i] = ch + '0';
    }
    y[8] = '\0';
}

PROXY_DECLARE(int) ap_proxyerror(request_rec *r, int statuscode, const char *message)
{
    apr_table_setn(r->notes, "error-notes",
	apr_pstrcat(r->pool, 
		"The proxy server could not handle the request "
		"<em><a href=\"", ap_escape_uri(r->pool, r->uri),
		"\">", ap_escape_html(r->pool, r->method),
		"&nbsp;", 
		ap_escape_html(r->pool, r->uri), "</a></em>.<p>\n"
		"Reason: <strong>",
		ap_escape_html(r->pool, message), 
		"</strong></p>", NULL));

    /* Allow "error-notes" string to be printed by ap_send_error_response() */
    apr_table_setn(r->notes, "verbose-error-to", apr_pstrdup(r->pool, "*"));

    r->status_line = apr_psprintf(r->pool, "%3.3u Proxy Error", statuscode);
    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
			 "proxy: %s returned by %s", message, r->uri);
    return statuscode;
}

static const char *
     proxy_get_host_of_request(request_rec *r)
{
    char *url, *user = NULL, *password = NULL, *err, *host;
    apr_port_t port;

    if (r->hostname != NULL)
	return r->hostname;

    /* Set url to the first char after "scheme://" */
    if ((url = strchr(r->uri, ':')) == NULL
	|| url[1] != '/' || url[2] != '/')
	return NULL;

    url = apr_pstrdup(r->pool, &url[1]);	/* make it point to "//", which is what proxy_canon_netloc expects */

    err = ap_proxy_canon_netloc(r->pool, &url, &user, &password, &host, &port);

    if (err != NULL)
	ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
		     "%s", err);

    r->hostname = host;

    return host;		/* ought to return the port, too */
}

/* Return TRUE if addr represents an IP address (or an IP network address) */
PROXY_DECLARE(int) ap_proxy_is_ipaddr(struct dirconn_entry *This, apr_pool_t *p)
{
    const char *addr = This->name;
    long ip_addr[4];
    int i, quads;
    long bits;

    /* if the address is given with an explicit netmask, use that */
    /* Due to a deficiency in apr_inet_addr(), it is impossible to parse */
    /* "partial" addresses (with less than 4 quads) correctly, i.e.  */
    /* 192.168.123 is parsed as 192.168.0.123, which is not what I want. */
    /* I therefore have to parse the IP address manually: */
    /*if (proxy_readmask(This->name, &This->addr.s_addr, &This->mask.s_addr) == 0) */
    /* addr and mask were set by proxy_readmask() */
    /*return 1; */

    /* Parse IP addr manually, optionally allowing */
    /* abbreviated net addresses like 192.168. */

    /* Iterate over up to 4 (dotted) quads. */
    for (quads = 0; quads < 4 && *addr != '\0'; ++quads) {
	char *tmp;

	if (*addr == '/' && quads > 0)	/* netmask starts here. */
	    break;

	if (!apr_isdigit(*addr))
	    return 0;		/* no digit at start of quad */

	ip_addr[quads] = strtol(addr, &tmp, 0);

	if (tmp == addr)	/* expected a digit, found something else */
	    return 0;

	if (ip_addr[quads] < 0 || ip_addr[quads] > 255) {
	    /* invalid octet */
	    return 0;
	}

	addr = tmp;

	if (*addr == '.' && quads != 3)
	    ++addr;		/* after the 4th quad, a dot would be illegal */
    }

    for (This->addr.s_addr = 0, i = 0; i < quads; ++i)
	This->addr.s_addr |= htonl(ip_addr[i] << (24 - 8 * i));

    if (addr[0] == '/' && apr_isdigit(addr[1])) {	/* net mask follows: */
	char *tmp;

	++addr;

	bits = strtol(addr, &tmp, 0);

	if (tmp == addr)	/* expected a digit, found something else */
	    return 0;

	addr = tmp;

	if (bits < 0 || bits > 32)	/* netmask must be between 0 and 32 */
	    return 0;

    }
    else {
	/* Determine (i.e., "guess") netmask by counting the */
	/* number of trailing .0's; reduce #quads appropriately */
	/* (so that 192.168.0.0 is equivalent to 192.168.)        */
	while (quads > 0 && ip_addr[quads - 1] == 0)
	    --quads;

	/* "IP Address should be given in dotted-quad form, optionally followed by a netmask (e.g., 192.168.111.0/24)"; */
	if (quads < 1)
	    return 0;

	/* every zero-byte counts as 8 zero-bits */
	bits = 8 * quads;

	if (bits != 32)		/* no warning for fully qualified IP address */
            ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
	      "Warning: NetMask not supplied with IP-Addr; guessing: %s/%ld\n",
		 inet_ntoa(This->addr), bits);
    }

    This->mask.s_addr = htonl(APR_INADDR_NONE << (32 - bits));

    if (*addr == '\0' && (This->addr.s_addr & ~This->mask.s_addr) != 0) {
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
	    "Warning: NetMask and IP-Addr disagree in %s/%ld\n",
		inet_ntoa(This->addr), bits);
	This->addr.s_addr &= This->mask.s_addr;
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
	    "         Set to %s/%ld\n",
		inet_ntoa(This->addr), bits);
    }

    if (*addr == '\0') {
	This->matcher = proxy_match_ipaddr;
	return 1;
    }
    else
	return (*addr == '\0');	/* okay iff we've parsed the whole string */
}

/* Return TRUE if addr represents an IP address (or an IP network address) */
static int proxy_match_ipaddr(struct dirconn_entry *This, request_rec *r)
{
    int i, ip_addr[4];
    struct in_addr addr, *ip;
    const char *host = proxy_get_host_of_request(r);

    if (host == NULL)   /* oops! */
       return 0;

    memset(&addr, '\0', sizeof addr);
    memset(ip_addr, '\0', sizeof ip_addr);

    if (4 == sscanf(host, "%d.%d.%d.%d", &ip_addr[0], &ip_addr[1], &ip_addr[2], &ip_addr[3])) {
	for (addr.s_addr = 0, i = 0; i < 4; ++i)
	    addr.s_addr |= htonl(ip_addr[i] << (24 - 8 * i));

	if (This->addr.s_addr == (addr.s_addr & This->mask.s_addr)) {
#if DEBUGGING
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                         "1)IP-Match: %s[%s] <-> ", host, inet_ntoa(addr));
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                         "%s/", inet_ntoa(This->addr));
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                         "%s", inet_ntoa(This->mask));
#endif
	    return 1;
	}
#if DEBUGGING
	else {
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                         "1)IP-NoMatch: %s[%s] <-> ", host, inet_ntoa(addr));
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                         "%s/", inet_ntoa(This->addr));
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                         "%s", inet_ntoa(This->mask));
	}
#endif
    }
    else {
	struct apr_sockaddr_t *reqaddr;

        if (apr_sockaddr_info_get(&reqaddr, host, APR_UNSPEC, 0, 0, r->pool)
	    != APR_SUCCESS) {
#if DEBUGGING
	    ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			 "2)IP-NoMatch: hostname=%s msg=Host not found", 
			 host);
#endif
	    return 0;
	}

	/* Try to deal with multiple IP addr's for a host */
	/* FIXME: This needs to be able to deal with IPv6 */
	while (reqaddr) {
	    ip = (struct in_addr *) reqaddr->ipaddr_ptr;
	    if (This->addr.s_addr == (ip->s_addr & This->mask.s_addr)) {
#if DEBUGGING
		ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			     "3)IP-Match: %s[%s] <-> ", host, 
			     inet_ntoa(*ip));
		ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			     "%s/", inet_ntoa(This->addr));
		ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			     "%s", inet_ntoa(This->mask));
#endif
		return 1;
	    }
#if DEBUGGING
	    else {
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			     "3)IP-NoMatch: %s[%s] <-> ", host, 
			     inet_ntoa(*ip));
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			     "%s/", inet_ntoa(This->addr));
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
			     "%s", inet_ntoa(This->mask));
	    }
#endif
	    reqaddr = reqaddr->next;
	}
    }

    return 0;
}

/* Return TRUE if addr represents a domain name */
PROXY_DECLARE(int) ap_proxy_is_domainname(struct dirconn_entry *This, apr_pool_t *p)
{
    char *addr = This->name;
    int i;

    /* Domain name must start with a '.' */
    if (addr[0] != '.')
        return 0;

    /* rfc1035 says DNS names must consist of "[-a-zA-Z0-9]" and '.' */
    for (i = 0; apr_isalnum(addr[i]) || addr[i] == '-' || addr[i] == '.'; ++i)
        continue;

#if 0
    if (addr[i] == ':') {
    ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
                     "@@@@ handle optional port in proxy_is_domainname()");
	/* @@@@ handle optional port */
    }
#endif

    if (addr[i] != '\0')
        return 0;

    /* Strip trailing dots */
    for (i = strlen(addr) - 1; i > 0 && addr[i] == '.'; --i)
        addr[i] = '\0';

    This->matcher = proxy_match_domainname;
    return 1;
}

/* Return TRUE if host "host" is in domain "domain" */
static int proxy_match_domainname(struct dirconn_entry *This, request_rec *r)
{
    const char *host = proxy_get_host_of_request(r);
    int d_len = strlen(This->name), h_len;

    if (host == NULL)		/* some error was logged already */
        return 0;

    h_len = strlen(host);

    /* @@@ do this within the setup? */
    /* Ignore trailing dots in domain comparison: */
    while (d_len > 0 && This->name[d_len - 1] == '.')
        --d_len;
    while (h_len > 0 && host[h_len - 1] == '.')
        --h_len;
    return h_len > d_len
        && strncasecmp(&host[h_len - d_len], This->name, d_len) == 0;
}

/* Return TRUE if host represents a host name */
PROXY_DECLARE(int) ap_proxy_is_hostname(struct dirconn_entry *This, apr_pool_t *p)
{
    struct apr_sockaddr_t *addr;
    char *host = This->name;
    int i;

    /* Host names must not start with a '.' */
    if (host[0] == '.')
        return 0;

    /* rfc1035 says DNS names must consist of "[-a-zA-Z0-9]" and '.' */
    for (i = 0; apr_isalnum(host[i]) || host[i] == '-' || host[i] == '.'; ++i);

    if (host[i] != '\0' || apr_sockaddr_info_get(&addr, host, APR_UNSPEC, 0, 0, p) != APR_SUCCESS)
        return 0;
    
    This->hostaddr = addr;

    /* Strip trailing dots */
    for (i = strlen(host) - 1; i > 0 && host[i] == '.'; --i)
        host[i] = '\0';

    This->matcher = proxy_match_hostname;
    return 1;
}

/* Return TRUE if host "host" is equal to host2 "host2" */
static int proxy_match_hostname(struct dirconn_entry *This, request_rec *r)
{
    char *host = This->name;
    const char *host2 = proxy_get_host_of_request(r);
    int h2_len;
    int h1_len;

    if (host == NULL || host2 == NULL)
        return 0; /* oops! */

    h2_len = strlen(host2);
    h1_len = strlen(host);

#if 0
    struct apr_sockaddr_t *addr = *This->hostaddr;

    /* Try to deal with multiple IP addr's for a host */
    while (addr) {
        if (addr->ipaddr_ptr == ? ? ? ? ? ? ? ? ? ? ? ? ?)
            return 1;
        addr = addr->next;
    }
#endif

    /* Ignore trailing dots in host2 comparison: */
    while (h2_len > 0 && host2[h2_len - 1] == '.')
        --h2_len;
    while (h1_len > 0 && host[h1_len - 1] == '.')
        --h1_len;
    return h1_len == h2_len
        && strncasecmp(host, host2, h1_len) == 0;
}

/* Return TRUE if addr is to be matched as a word */
PROXY_DECLARE(int) ap_proxy_is_word(struct dirconn_entry *This, apr_pool_t *p)
{
    This->matcher = proxy_match_word;
    return 1;
}

/* Return TRUE if string "str2" occurs literally in "str1" */
static int proxy_match_word(struct dirconn_entry *This, request_rec *r)
{
    const char *host = proxy_get_host_of_request(r);
    return host != NULL && ap_strstr_c(host, This->name) != NULL;
}

/* checks whether a host in uri_addr matches proxyblock */
PROXY_DECLARE(int) ap_proxy_checkproxyblock(request_rec *r, proxy_server_conf *conf, 
                             apr_sockaddr_t *uri_addr)
{
    int j;
    apr_sockaddr_t * src_uri_addr = uri_addr;
    /* XXX FIXME: conf->noproxies->elts is part of an opaque structure */
    for (j = 0; j < conf->noproxies->nelts; j++) {
        struct noproxy_entry *npent = (struct noproxy_entry *) conf->noproxies->elts;
        struct apr_sockaddr_t *conf_addr = npent[j].addr;
        uri_addr = src_uri_addr;
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "proxy: checking remote machine [%s] against [%s]", uri_addr->hostname, npent[j].name);
        if ((npent[j].name && ap_strstr_c(uri_addr->hostname, npent[j].name))
            || npent[j].name[0] == '*') {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
                         "proxy: connect to remote machine %s blocked: name %s matched", uri_addr->hostname, npent[j].name);
            return HTTP_FORBIDDEN;
        }
        while (conf_addr) {
            while (uri_addr) {
                char *conf_ip;
                char *uri_ip;
                apr_sockaddr_ip_get(&conf_ip, conf_addr);
                apr_sockaddr_ip_get(&uri_ip, uri_addr);
                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                             "proxy: ProxyBlock comparing %s and %s", conf_ip, uri_ip);
                if (!apr_strnatcasecmp(conf_ip, uri_ip)) {
                    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, r->server,
                                 "proxy: connect to remote machine %s blocked: IP %s matched", uri_addr->hostname, conf_ip);
                    return HTTP_FORBIDDEN;
                }
                uri_addr = uri_addr->next;
            }
            conf_addr = conf_addr->next;
        }
    }
    return OK;
}

/* set up the minimal filter set */
PROXY_DECLARE(int) ap_proxy_pre_http_request(conn_rec *c, request_rec *r)
{
    ap_add_input_filter("HTTP_IN", NULL, r, c);
    return OK;
}

/* converts a series of buckets into a string 
 * XXX: BillS says this function performs essentially the same function as 
 * ap_rgetline() in protocol.c. Deprecate this function and use ap_rgetline() 
 * instead? I think ap_proxy_string_read() will not work properly on non ASCII
 * (EBCDIC) machines either.
 */
PROXY_DECLARE(apr_status_t) ap_proxy_string_read(conn_rec *c, apr_bucket_brigade *bb,
                                                 char *buff, apr_size_t bufflen, int *eos)
{
    apr_bucket *e;
    apr_status_t rv;
    char *pos = buff;
    char *response;
    int found = 0;
    apr_size_t len;

    /* start with an empty string */
    buff[0] = 0;
    *eos = 0;

    /* loop through each brigade */
    while (!found) {
        /* get brigade from network one line at a time */
        if (APR_SUCCESS != (rv = ap_get_brigade(c->input_filters, bb, 
                                                AP_MODE_GETLINE,
                                                APR_BLOCK_READ,
                                                0))) {
            return rv;
        }
        /* loop through each bucket */
        while (!found) {
            if (*eos || APR_BRIGADE_EMPTY(bb)) {
                /* The connection aborted or timed out */
                return APR_ECONNABORTED;
            }
            e = APR_BRIGADE_FIRST(bb);
            if (APR_BUCKET_IS_EOS(e)) {
                *eos = 1;
            }
            else {
                if (APR_SUCCESS != apr_bucket_read(e, (const char **)&response, &len, APR_BLOCK_READ)) {
                    return rv;
                }
                /* is string LF terminated? 
                 * XXX: This check can be made more efficient by simply checking 
                 * if the last character in the 'response' buffer is an ASCII_LF.
                 * See ap_rgetline() for an example.
                 */
                if (memchr(response, APR_ASCII_LF, len)) {
                    found = 1;
                }
                /* concat strings until buff is full - then throw the data away */
                if (len > ((bufflen-1)-(pos-buff))) {
                    len = (bufflen-1)-(pos-buff);
                }
                if (len > 0) {
                    pos = apr_cpystrn(pos, response, len);
                }
            }
            APR_BUCKET_REMOVE(e);
            apr_bucket_destroy(e);
        }
    }

    return APR_SUCCESS;
}

/* unmerge an element in the table */
PROXY_DECLARE(void) ap_proxy_table_unmerge(apr_pool_t *p, apr_table_t *t, char *key)
{
    apr_off_t offset = 0;
    apr_off_t count = 0;
    char *value = NULL;

    /* get the value to unmerge */
    const char *initial = apr_table_get(t, key);
    if (!initial) {
        return;
    }
    value = apr_pstrdup(p, initial);

    /* remove the value from the headers */
    apr_table_unset(t, key);

    /* find each comma */
    while (value[count]) {
        if (value[count] == ',') {
            value[count] = 0;
            apr_table_add(t, key, value + offset);
            offset = count + 1;
        }
        count++;
    }
    apr_table_add(t, key, value + offset);
}

PROXY_DECLARE(int) ap_proxy_connect_to_backend(apr_socket_t **newsock,
                                               const char *proxy_function,
                                               apr_sockaddr_t *backend_addr,
                                               const char *backend_name,
                                               proxy_server_conf *conf,
                                               server_rec *s,
                                               apr_pool_t *p)
{
    apr_status_t rv;
    int connected = 0;
    int loglevel;
    
    while (backend_addr && !connected) {
        if ((rv = apr_socket_create(newsock, backend_addr->family,
                                    SOCK_STREAM, p)) != APR_SUCCESS) {
            loglevel = backend_addr->next ? APLOG_DEBUG : APLOG_ERR;
            ap_log_error(APLOG_MARK, loglevel, rv, s,
                         "proxy: %s: error creating fam %d socket for target %s",
                         proxy_function,
                         backend_addr->family,
                         backend_name);
            /* this could be an IPv6 address from the DNS but the
             * local machine won't give us an IPv6 socket; hopefully the
             * DNS returned an additional address to try
             */
            backend_addr = backend_addr->next;
            continue;
        }

#if !defined(TPF) && !defined(BEOS)
        if (conf->recv_buffer_size > 0 &&
            (rv = apr_socket_opt_set(*newsock, APR_SO_RCVBUF,
                                     conf->recv_buffer_size))) {
            ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
                         "apr_socket_opt_set(SO_RCVBUF): Failed to set "
                         "ProxyReceiveBufferSize, using default");
        }
#endif

        /* Set a timeout on the socket */
        if (conf->timeout_set == 1) {
            apr_socket_timeout_set(*newsock, conf->timeout);
        }
        else {
             apr_socket_timeout_set(*newsock, s->timeout);
        }

        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                     "proxy: %s: fam %d socket created to connect to %s",
                     proxy_function, backend_addr->family, backend_name);

        /* make the connection out of the socket */
        rv = apr_connect(*newsock, backend_addr);

        /* if an error occurred, loop round and try again */
        if (rv != APR_SUCCESS) {
            apr_socket_close(*newsock);
            loglevel = backend_addr->next ? APLOG_DEBUG : APLOG_ERR;
            ap_log_error(APLOG_MARK, loglevel, rv, s,
                         "proxy: %s: attempt to connect to %pI (%s) failed",
                         proxy_function,
                         backend_addr,
                         backend_name);
            backend_addr = backend_addr->next;
            continue;
        }
        connected = 1;
    }
    return connected ? 0 : 1;
}
    
