proxy_util.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

/* 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"

#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

/* Global balancer counter */
int PROXY_DECLARE_DATA proxy_lb_workers = 0;
static int lb_workers_limit = 0;

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 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 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, 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;
}

/*
 * If the date is a valid RFC 850 date or asctime() date, then it
 * is converted to the RFC 1123 format.
 */
PROXY_DECLARE(const char *)
     ap_proxy_date_canon(apr_pool_t *p, const char *date)
{
    apr_status_t rv;
    char* ndate;

    apr_time_t time = apr_date_parse_http(date);
    if (!time) {
        return date;
    }

    ndate = apr_palloc(p, APR_RFC822_DATE_LEN);
    rv = apr_rfc822_date(ndate, time);
    if (rv != APR_SUCCESS) {
        return date;
    }

    return ndate;
}

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

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

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

    return rp;
}


/*
 * 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 {