proxy_util.c

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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"
#include "ap_mpm.h"
#include "scoreboard.h"
#include "apr_version.h"
#include "apr_hash.h"
#include "proxy_util.h"
#include "ajp.h"
#include "scgi.h"

#if APR_HAVE_UNISTD_H
#include <unistd.h>         /* for getpid() */
#endif

#if (APR_MAJOR_VERSION < 1)
#undef apr_socket_create
#define apr_socket_create apr_socket_create_ex
#endif

#if APR_HAVE_SYS_UN_H
#include <sys/un.h>
#endif
#if (APR_MAJOR_VERSION < 2)
#include "apr_support.h"        /* for apr_wait_for_io_or_timeout() */
#endif

APLOG_USE_MODULE(proxy);

/*
 * Opaque structure containing target server info when
 * using a forward proxy.
 * Up to now only used in combination with HTTP CONNECT.
 */
typedef struct {
    int          use_http_connect; /* Use SSL Tunneling via HTTP CONNECT */
    const char   *target_host;     /* Target hostname */
    apr_port_t   target_port;      /* Target port */
    const char   *proxy_auth;      /* Proxy authorization */
} forward_info;

/* Global balancer counter */
int PROXY_DECLARE_DATA proxy_lb_workers = 0;
static int lb_workers_limit = 0;
const apr_strmatch_pattern PROXY_DECLARE_DATA *ap_proxy_strmatch_path;
const apr_strmatch_pattern PROXY_DECLARE_DATA *ap_proxy_strmatch_domain;

extern apr_global_mutex_t *proxy_mutex;

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)

PROXY_DECLARE(apr_status_t) ap_proxy_strncpy(char *dst, const char *src,
                                             apr_size_t dlen)
{
    char *thenil;
    apr_size_t thelen;

    /* special case handling */
    if (!dlen) {
        /* XXX: APR_ENOSPACE would be better */
        return APR_EGENERAL;
    }
    if (!src) {
        *dst = '\0';
        return APR_SUCCESS;
    }
    thenil = apr_cpystrn(dst, src, dlen);
    thelen = thenil - dst;
    if (src[thelen] == '\0') {
        return APR_SUCCESS;
    }
    return APR_EGENERAL;
}

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

#if !APR_CHARSET_EBCDIC
    int 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 forcedec,
                                       int proxyreq)
{
    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. do not decode reverse proxied URLs
 * unless specifically forced
 */
        if ((forcedec || (proxyreq && proxyreq != PROXYREQ_REVERSE)) && 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 separating '/' */
    }

    /* 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, 0);
            if (password == NULL) {
                return "Bad %-escape in URL (password)";
            }
        }

        user = ap_proxy_canonenc(p, user, strlen(user), enc_user, 1, 0);
        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;
}

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

    r->status_line = apr_psprintf(r->pool, "%3.3u Proxy Error", statuscode);
    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00898) "%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 = NULL;
    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, APLOGNO(00899) "%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, APLOGNO(00900)
                         "Warning: NetMask not supplied with IP-Addr; guessing: %s/%ld",
                         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, APLOGNO(00901)
                     "Warning: NetMask and IP-Addr disagree in %s/%ld",
                     inet_ntoa(This->addr), bits);
        This->addr.s_addr &= This->mask.s_addr;
        ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00902)
                     "         Set to %s/%ld", 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) {
            /* ap_proxy_is_ipaddr() already confirmed that we have
             * a valid octet in ip_addr[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, APLOGNO(00903)
                         "1)IP-Match: %s[%s] <-> ", host, inet_ntoa(addr));
            ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00904)
                         "%s/", inet_ntoa(This->addr));
            ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00905)
                         "%s", inet_ntoa(This->mask));
#endif
            return 1;
        }
#if DEBUGGING
        else {
            ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00906)
                         "1)IP-NoMatch: %s[%s] <-> ", host, inet_ntoa(addr));
            ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00907)
                         "%s/", inet_ntoa(This->addr));
            ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00908)
                         "%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, APLOGNO(00909)
             "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, APLOGNO(00910)
                             "3)IP-Match: %s[%s] <-> ", host, inet_ntoa(*ip));
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00911)
                             "%s/", inet_ntoa(This->addr));
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00912)
                             "%s", inet_ntoa(This->mask));
#endif
                return 1;
            }
#if DEBUGGING
            else {
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00913)
                             "3)IP-NoMatch: %s[%s] <-> ", host, inet_ntoa(*ip));
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00914)
                             "%s/", inet_ntoa(This->addr));
                ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL, APLOGNO(00915)
                             "%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, APLOGNO(03234)
                     "@@@@ 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;
}

/* Backwards-compatible interface. */
PROXY_DECLARE(int) ap_proxy_checkproxyblock(request_rec *r, proxy_server_conf *conf,
                             apr_sockaddr_t *uri_addr)
{
    return ap_proxy_checkproxyblock2(r, conf, uri_addr->hostname, uri_addr);
}

#define MAX_IP_STR_LEN (46)

PROXY_DECLARE(int) ap_proxy_checkproxyblock2(request_rec *r, proxy_server_conf *conf,
                                             const char *hostname, apr_sockaddr_t *addr)
{
    int j;

    /* 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;

        ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
                      "checking remote machine [%s] against [%s]",
                      hostname, npent[j].name);
        if (ap_strstr_c(hostname, npent[j].name) || npent[j].name[0] == '*') {
            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(00916)
                          "connect to remote machine %s blocked: name %s "
                          "matched", hostname, npent[j].name);
            return HTTP_FORBIDDEN;
        }

        /* No IP address checks if no IP address was passed in,
         * i.e. the forward address proxy case, where this server does
         * not resolve the hostname.  */
        if (!addr)
            continue;

        for (conf_addr = npent[j].addr; conf_addr; conf_addr = conf_addr->next) {
            char caddr[MAX_IP_STR_LEN], uaddr[MAX_IP_STR_LEN];
            apr_sockaddr_t *uri_addr;

            if (apr_sockaddr_ip_getbuf(caddr, sizeof caddr, conf_addr))
                continue;

            for (uri_addr = addr; uri_addr; uri_addr = uri_addr->next) {
                if (apr_sockaddr_ip_getbuf(uaddr, sizeof uaddr, uri_addr))
                    continue;
                ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
                              "ProxyBlock comparing %s and %s", caddr, uaddr);
                if (!strcmp(caddr, uaddr)) {
                    ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(00917)
                                  "connect to remote machine %s blocked: "
                                  "IP %s matched", hostname, caddr);
                    return HTTP_FORBIDDEN;
                }
            }
        }
    }

    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;
}

PROXY_DECLARE(const char *) ap_proxy_location_reverse_map(request_rec *r,
                              proxy_dir_conf *conf, const char *url)
{
    proxy_req_conf *rconf;
    struct proxy_alias *ent;
    int i, l1, l2;
    char *u;

    /*
     * XXX FIXME: Make sure this handled the ambiguous case of the :<PORT>
     * after the hostname
     * XXX FIXME: Ensure the /uri component is a case sensitive match
     */
    if (r->proxyreq != PROXYREQ_REVERSE) {
        return url;
    }

    l1 = strlen(url);
    if (conf->interpolate_env == 1) {
        rconf = ap_get_module_config(r->request_config, &proxy_module);
        ent = (struct proxy_alias *)rconf->raliases->elts;
    }
    else {
        ent = (struct proxy_alias *)conf->raliases->elts;
    }
    for (i = 0; i < conf->raliases->nelts; i++) {
        proxy_server_conf *sconf = (proxy_server_conf *)
            ap_get_module_config(r->server->module_config, &proxy_module);
        proxy_balancer *balancer;
        const char *real = ent[i].real;
        /*
         * First check if mapping against a balancer and see
         * if we have such a entity. If so, then we need to
         * find the particulars of the actual worker which may
         * or may not be the right one... basically, we need
         * to find which member actually handled this request.
         */
        if (ap_proxy_valid_balancer_name((char *)real, 0) &&
            (balancer = ap_proxy_get_balancer(r->pool, sconf, real, 1))) {
            int n, l3 = 0;
            proxy_worker **worker = (proxy_worker **)balancer->workers->elts;
            const char *urlpart = ap_strchr_c(real + sizeof(BALANCER_PREFIX) - 1, '/');
            if (urlpart) {
                if (!urlpart[1])
                    urlpart = NULL;
                else
                    l3 = strlen(urlpart);
            }
            /* The balancer comparison is a bit trickier.  Given the context
             *   BalancerMember balancer://alias http://example.com/foo
             *   ProxyPassReverse /bash balancer://alias/bar
             * translate url http://example.com/foo/bar/that to /bash/that
             */
            for (n = 0; n < balancer->workers->nelts; n++) {
                l2 = strlen((*worker)->s->name);
                if (urlpart) {
                    /* urlpart (l3) assuredly starts with its own '/' */
                    if ((*worker)->s->name[l2 - 1] == '/')
                        --l2;
                    if (l1 >= l2 + l3
                            && strncasecmp((*worker)->s->name, url, l2) == 0
                            && strncmp(urlpart, url + l2, l3) == 0) {
                        u = apr_pstrcat(r->pool, ent[i].fake, &url[l2 + l3],
                                        NULL);
                        return ap_is_url(u) ? u : ap_construct_url(r->pool, u, r);
                    }
                }
                else if (l1 >= l2 && strncasecmp((*worker)->s->name, url, l2) == 0) {
                    /* edge case where fake is just "/"... avoid double slash */
                    if ((ent[i].fake[0] == '/') && (ent[i].fake[1] == 0) && (url[l2] == '/')) {
                        u = apr_pstrdup(r->pool, &url[l2]);
                    } else {
                        u = apr_pstrcat(r->pool, ent[i].fake, &url[l2], NULL);
                    }
                    return ap_is_url(u) ? u : ap_construct_url(r->pool, u, r);
                }
                worker++;
            }
        }
        else {
            const char *part = url;
            l2 = strlen(real);
            if (real[0] == '/') {
                part = ap_strstr_c(url, "://");
                if (part) {
                    part = ap_strchr_c(part+3, '/');
                    if (part) {
                        l1 = strlen(part);
                    }
                    else {
                        part = url;
                    }
                }
                else {
                    part = url;
                }
            }
            if (l2 > 0 && l1 >= l2 && strncasecmp(real, part, l2) == 0) {
                u = apr_pstrcat(r->pool, ent[i].fake, &part[l2], NULL);
                return ap_is_url(u) ? u : ap_construct_url(r->pool, u, r);
            }
        }
    }

    return url;
}

/*
 * Cookies are a bit trickier to match: we've got two substrings to worry
 * about, and we can't just find them with strstr 'cos of case.  Regexp
 * matching would be an easy fix, but for better consistency with all the
 * other matches we'll refrain and use apr_strmatch to find path=/domain=
 * and stick to plain strings for the config values.
 */
PROXY_DECLARE(const char *) ap_proxy_cookie_reverse_map(request_rec *r,
                              proxy_dir_conf *conf, const char *str)
{
    proxy_req_conf *rconf = ap_get_module_config(r->request_config,
                                                 &proxy_module);
    struct proxy_alias *ent;
    apr_size_t len = strlen(str);
    const char *newpath = NULL;
    const char *newdomain = NULL;
    const char *pathp;
    const char *domainp;
    const char *pathe = NULL;
    const char *domaine = NULL;
    apr_size_t l1, l2, poffs = 0, doffs = 0;
    int i;
    int ddiff = 0;
    int pdiff = 0;
    char *ret;

    if (r->proxyreq != PROXYREQ_REVERSE) {
        return str;
    }

   /*
    * Find the match and replacement, but save replacing until we've done
    * both path and domain so we know the new strlen
    */
    if ((pathp = apr_strmatch(ap_proxy_strmatch_path, str, len)) != NULL) {
        pathp += 5;
        poffs = pathp - str;
        pathe = ap_strchr_c(pathp, ';');
        l1 = pathe ? (pathe - pathp) : strlen(pathp);
        pathe = pathp + l1 ;
        if (conf->interpolate_env == 1) {
            ent = (struct proxy_alias *)rconf->cookie_paths->elts;
        }
        else {
            ent = (struct proxy_alias *)conf->cookie_paths->elts;
        }
        for (i = 0; i < conf->cookie_paths->nelts; i++) {
            l2 = strlen(ent[i].fake);
            if (l1 >= l2 && strncmp(ent[i].fake, pathp, l2) == 0) {
                newpath = ent[i].real;
                pdiff = strlen(newpath) - l1;
                break;
            }
        }
    }

    if ((domainp = apr_strmatch(ap_proxy_strmatch_domain, str, len)) != NULL) {
        domainp += 7;
        doffs = domainp - str;
        domaine = ap_strchr_c(domainp, ';');
        l1 = domaine ? (domaine - domainp) : strlen(domainp);
        domaine = domainp + l1;
        if (conf->interpolate_env == 1) {
            ent = (struct proxy_alias *)rconf->cookie_domains->elts;
        }
        else {