proxy_util.c

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    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)) {