mod_proxy_ftp.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.
 */

/* FTP routines for Apache proxy */

#include "mod_proxy.h"
#if APR_HAVE_TIME_H
#include <time.h>
#endif
#include "apr_version.h"

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

#define AUTODETECT_PWD
/* Automatic timestamping (Last-Modified header) based on MDTM is used if:
 * 1) the FTP server supports the MDTM command and
 * 2) HAVE_TIMEGM (preferred) or HAVE_GMTOFF is available at compile time
 */
#define USE_MDTM


module AP_MODULE_DECLARE_DATA proxy_ftp_module;

/*
 * Decodes a '%' escaped string, and returns the number of characters
 */
static int decodeenc(char *x)
{
    int i, j, ch;

    if (x[0] == '\0')
        return 0;               /* special case for no characters */
    for (i = 0, j = 0; x[i] != '\0'; i++, j++) {
        /* decode it if not already done */
        ch = x[i];
        if (ch == '%' && apr_isxdigit(x[i + 1]) && apr_isxdigit(x[i + 2])) {
            ch = ap_proxy_hex2c(&x[i + 1]);
            i += 2;
        }
        x[j] = ch;
    }
    x[j] = '\0';
    return j;
}

/*
 * Escape the globbing characters in a path used as argument to
 * the FTP commands (SIZE, CWD, RETR, MDTM, ...).
 * ftpd assumes '\\' as a quoting character to escape special characters.
 * Returns: escaped string
 */
#define FTP_GLOBBING_CHARS "*?[{~"
static char *ftp_escape_globbingchars(apr_pool_t *p, const char *path)
{
    char *ret = apr_palloc(p, 2*strlen(path)+sizeof(""));
    char *d;
    for (d = ret; *path; ++path) {
        if (strchr(FTP_GLOBBING_CHARS, *path) != NULL)
            *d++ = '\\';
        *d++ = *path;
    }
    *d = '\0';
    return ret;
}

/*
 * Check for globbing characters in a path used as argument to
 * the FTP commands (SIZE, CWD, RETR, MDTM, ...).
 * ftpd assumes '\\' as a quoting character to escape special characters.
 * Returns: 0 (no globbing chars, or all globbing chars escaped), 1 (globbing chars)
 */
static int ftp_check_globbingchars(const char *path)
{
    for ( ; *path; ++path) {
        if (*path == '\\')
        ++path;
        if (*path != '\0' && strchr(FTP_GLOBBING_CHARS, *path) != NULL)
            return TRUE;
    }
    return FALSE;
}

/*
 * checks an encoded ftp string for bad characters, namely, CR, LF or
 * non-ascii character
 */
static int ftp_check_string(const char *x)
{
    int i, ch = 0;
#if APR_CHARSET_EBCDIC
    char buf[1];
#endif

    for (i = 0; x[i] != '\0'; i++) {
        ch = x[i];
        if (ch == '%' && apr_isxdigit(x[i + 1]) && apr_isxdigit(x[i + 2])) {
            ch = ap_proxy_hex2c(&x[i + 1]);
            i += 2;
        }
#if !APR_CHARSET_EBCDIC
        if (ch == '\015' || ch == '\012' || (ch & 0x80))
#else                           /* APR_CHARSET_EBCDIC */
        if (ch == '\r' || ch == '\n')
            return 0;
        buf[0] = ch;
        ap_xlate_proto_to_ascii(buf, 1);
        if (buf[0] & 0x80)
#endif                          /* APR_CHARSET_EBCDIC */
            return 0;
    }
    return 1;
}

/*
 * Canonicalise ftp URLs.
 */
static int proxy_ftp_canon(request_rec *r, char *url)
{
    char *user, *password, *host, *path, *parms, *strp, sport[7];
    apr_pool_t *p = r->pool;
    const char *err;
    apr_port_t port, def_port;

    /* */
    if (strncasecmp(url, "ftp:", 4) == 0) {
        url += 4;
    }
    else {
        return DECLINED;
    }
    def_port = apr_uri_port_of_scheme("ftp");

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                 "proxy: FTP: canonicalising URL %s", url);

    port = def_port;
    err = ap_proxy_canon_netloc(p, &url, &user, &password, &host, &port);
    if (err)
        return HTTP_BAD_REQUEST;
    if (user != NULL && !ftp_check_string(user))
        return HTTP_BAD_REQUEST;
    if (password != NULL && !ftp_check_string(password))
        return HTTP_BAD_REQUEST;

    /* now parse path/parameters args, according to rfc1738 */
    /*
     * N.B. if this isn't a true proxy request, then the URL path (but not
     * query args) has already been decoded. This gives rise to the problem
     * of a ; being decoded into the path.
     */
    strp = strchr(url, ';');
    if (strp != NULL) {
        *(strp++) = '\0';
        parms = ap_proxy_canonenc(p, strp, strlen(strp), enc_parm, 0,
                                  r->proxyreq);
        if (parms == NULL)
            return HTTP_BAD_REQUEST;
    }
    else
        parms = "";

    path = ap_proxy_canonenc(p, url, strlen(url), enc_path, 0, r->proxyreq);
    if (path == NULL)
        return HTTP_BAD_REQUEST;
    if (!ftp_check_string(path))
        return HTTP_BAD_REQUEST;

    if (r->proxyreq && r->args != NULL) {
        if (strp != NULL) {
            strp = ap_proxy_canonenc(p, r->args, strlen(r->args), enc_parm, 1, r->proxyreq);
            if (strp == NULL)
                return HTTP_BAD_REQUEST;
            parms = apr_pstrcat(p, parms, "?", strp, NULL);
        }
        else {
            strp = ap_proxy_canonenc(p, r->args, strlen(r->args), enc_fpath, 1, r->proxyreq);
            if (strp == NULL)
                return HTTP_BAD_REQUEST;
            path = apr_pstrcat(p, path, "?", strp, NULL);
        }
        r->args = NULL;
    }

/* now, rebuild URL */

    if (port != def_port)
        apr_snprintf(sport, sizeof(sport), ":%d", port);
    else
        sport[0] = '\0';

    if (ap_strchr_c(host, ':')) { /* if literal IPv6 address */
        host = apr_pstrcat(p, "[", host, "]", NULL);
    }
    r->filename = apr_pstrcat(p, "proxy:ftp://", (user != NULL) ? user : "",
                              (password != NULL) ? ":" : "",
                              (password != NULL) ? password : "",
                          (user != NULL) ? "@" : "", host, sport, "/", path,
                              (parms[0] != '\0') ? ";" : "", parms, NULL);

    return OK;
}

/* we chop lines longer than 80 characters */
#define MAX_LINE_LEN 80

/*
 * Reads response lines, returns both the ftp status code and
 * remembers the response message in the supplied buffer
 */
static int ftp_getrc_msg(conn_rec *ftp_ctrl, apr_bucket_brigade *bb, char *msgbuf, int msglen)
{
    int status;
    char response[MAX_LINE_LEN];
    char buff[5];
    char *mb = msgbuf, *me = &msgbuf[msglen];
    apr_status_t rv;
    int eos;

    if (APR_SUCCESS != (rv = ap_proxy_string_read(ftp_ctrl, bb, response, sizeof(response), &eos))) {
        return -1;
    }
/*
    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
                 "proxy: <FTP: %s", response);
*/
    if (!apr_isdigit(response[0]) || !apr_isdigit(response[1]) ||
    !apr_isdigit(response[2]) || (response[3] != ' ' && response[3] != '-'))
        status = 0;
    else
        status = 100 * response[0] + 10 * response[1] + response[2] - 111 * '0';

    mb = apr_cpystrn(mb, response + 4, me - mb);

    if (response[3] == '-') {
        memcpy(buff, response, 3);
        buff[3] = ' ';
        do {
            if (APR_SUCCESS != (rv = ap_proxy_string_read(ftp_ctrl, bb, response, sizeof(response), &eos))) {
                return -1;
            }
            mb = apr_cpystrn(mb, response + (' ' == response[0] ? 1 : 4), me - mb);
        } while (memcmp(response, buff, 4) != 0);
    }

    return status;
}

/* this is a filter that turns a raw ASCII directory listing into pretty HTML */

/* ideally, mod_proxy should simply send the raw directory list up the filter
 * stack to mod_autoindex, which in theory should turn the raw ascii into
 * pretty html along with all the bells and whistles it provides...
 *
 * all in good time...! :)
 */

typedef struct {
    apr_bucket_brigade *in;
    char buffer[MAX_STRING_LEN];
    enum {
        HEADER, BODY, FOOTER
    }    state;
}      proxy_dir_ctx_t;

/* fallback regex for ls -s1;  ($0..$2) == 3 */
#define LS_REG_PATTERN "^ *([0-9]+) +([^ ]+)$"
#define LS_REG_MATCH   3

static apr_status_t proxy_send_dir_filter(ap_filter_t *f,
                                          apr_bucket_brigade *in)
{
    request_rec *r = f->r;
    conn_rec *c = r->connection;
    apr_pool_t *p = r->pool;
    apr_bucket_brigade *out = apr_brigade_create(p, c->bucket_alloc);
    apr_status_t rv;

    register int n;
    char *dir, *path, *reldir, *site, *str, *type;

    const char *pwd = apr_table_get(r->notes, "Directory-PWD");
    const char *readme = apr_table_get(r->notes, "Directory-README");

    proxy_dir_ctx_t *ctx = f->ctx;

    if (!ctx) {
        f->ctx = ctx = apr_pcalloc(p, sizeof(*ctx));
        ctx->in = apr_brigade_create(p, c->bucket_alloc);
        ctx->buffer[0] = 0;
        ctx->state = HEADER;
    }

    /* combine the stored and the new */
    APR_BRIGADE_CONCAT(ctx->in, in);

    if (HEADER == ctx->state) {

        /* basedir is either "", or "/%2f" for the "squid %2f hack" */
        const char *basedir = "";  /* By default, path is relative to the $HOME dir */
        char *wildcard = NULL;
        const char *escpath;

        /* Save "scheme://site" prefix without password */
        site = apr_uri_unparse(p, &f->r->parsed_uri, APR_URI_UNP_OMITPASSWORD | APR_URI_UNP_OMITPATHINFO);
        /*
         * In the reverse proxy case we usually have no site. So contruct
         * one.
         */
        if ((*site == '\0') && (r->proxyreq == PROXYREQ_REVERSE)) {
            site = ap_construct_url(p, "", r);
        }
        /* ... and path without query args */
        path = apr_uri_unparse(p, &f->r->parsed_uri, APR_URI_UNP_OMITSITEPART | APR_URI_UNP_OMITQUERY);

        /* If path began with /%2f, change the basedir */
        if (strncasecmp(path, "/%2f", 4) == 0) {
            basedir = "/%2f";
        }

        /* Strip off a type qualifier. It is ignored for dir listings */
        if ((type = strstr(path, ";type=")) != NULL)
            *type++ = '\0';

        (void)decodeenc(path);