/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * This program is free software; you can redistribute it and/or       *
 * modify it under the terms of the GNU General Public License as      *
 * published by the Free Software Foundation; either version 2 of the  *
 * License, or (at your option) any later version.                     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * mod_bunzip2.c: pipe documents through a "send-bunzip2" handler.
 *
 * Written and copyrighted by Helge Oldach <mod_bunzip2@oldach.net>
 *
 *	04 February 2001	initial release (naive adaption of mod_gunzip)
 *	29 July 2002		Remove ourselves as the default handler.
 *
 */

#include "httpd.h"
#include "http_config.h"
#include "http_request.h"
#include "http_protocol.h"
#include "http_log.h"
#include "http_main.h"
#include "util_script.h"
#include "bzlib.h"

#ifndef BUFSIZ
/* should come from stdio.h */
#define BUFSIZ 4096
#endif

static int bunzip2_handler(request_rec *r)
{
    FILE *f, *fnew;
    int errstatus;
    request_rec *parent;
    BZFILE *zf;
    unsigned char peek[2];
    const char *accept;

    r->allowed |= (1 << M_GET);
    if (r->method_number != M_GET)
	return DECLINED;

    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, r,
	r->content_encoding ? "---%s (%s)---" : "---%s---",
	r->filename, r->content_encoding);

    if (r->finfo.st_mode == 0) {
	ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
	    "File does not exist: %s",
	    (r->path_info
	    ? ap_pstrcat(r->pool, r->filename, r->path_info, NULL)
	    : r->filename));
	return HTTP_NOT_FOUND;
    }

    if (!(f = ap_pfopen(r->pool, r->filename, "r"))) {
	ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
	    "file permissions deny server access: %s", r->filename);
	return HTTP_FORBIDDEN;
    }

    /* cannot clone the FILE* but need to open separately for peek-ahead
    otherwise BZ2_bzdopen gets confused */
    if (!(fnew = ap_pfopen(r->pool, r->filename, "r")) ||
	fread(peek, sizeof peek[0], sizeof peek, fnew) != sizeof peek ||
	ap_pfclose(r->pool, fnew)) {
	ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
	    "Cannot peek at %d bytes: %s",
	    sizeof peek[0] * sizeof peek, r->filename);
	return DECLINED;
    }

    if (peek[0] != 'B' || peek[1] != 'Z') {
	ap_log_rerror(APLOG_MARK, APLOG_DEBUG, r,
	    "Not bzip2 format (0x%02.2x 0x%02.2x): %s",
	    peek[0], peek[1], r->filename);
	return DECLINED;
    }

    if ((accept = ap_table_get(r->headers_in, "Accept-Encoding")) != NULL &&
	strstr(accept, "bzip2") != NULL) {
	r->content_encoding = ap_pstrdup(r->pool, "bzip2");
	ap_log_rerror(APLOG_MARK, APLOG_DEBUG, r,
	    "Client accepts bzip2, no bunzip2 needed: %s",
	    r->filename);
	return DECLINED;
    }

    if (r->content_encoding != NULL &&
	strstr(r->content_encoding, "bzip2") != NULL) {
	ap_log_rerror(APLOG_MARK, APLOG_DEBUG, r,
	    "Content-Encoding \"%s\" unset", r->content_encoding);
	r->content_encoding = NULL;
    }
    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, r,
	"Client doesn't accept bzip2: %s", r->filename);

#ifdef PLAIN
#else
    if (!(zf = BZ2_bzdopen(fileno(f), "r"))) {
	ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
	    "file permissions deny server access: %s", r->filename);
	return HTTP_FORBIDDEN;
    }
#endif

    ap_update_mtime(r, r->finfo.st_mtime);
    ap_set_last_modified(r);
    ap_set_etag(r);
    /* not supported: ap_table_setn(r->headers_out, "Accept-Ranges", "bytes"); */
    if (((errstatus = ap_meets_conditions(r)) != OK) /* not supported:
	|| (errstatus = ap_set_content_length(r, r->finfo.st_size)) */) {
#ifdef PLAIN
#else
	BZ2_bzclose(zf);
#endif
	return errstatus;
    }

    ap_send_http_header(r);
    if (!r->header_only) {
	static char buf[BUFSIZ];
	int nread, nwritten;

	ap_log_rerror(APLOG_MARK, APLOG_DEBUG, r,
	    "Bunzip2 file: \"%s\"", r->filename);

	while ((nread =
#ifdef PLAIN
	    fread(buf, 1, BUFSIZ, f)
#else
	    BZ2_bzread(zf, buf, BUFSIZ)
#endif
	    ) > 0) {
	    ap_soft_timeout("send bunzip2", r);

	    while (!r->connection->aborted && nread > 0) {
		nwritten = ap_rwrite(buf, nread, r);
		if (nwritten > 0) {
		    ap_reset_timeout(r);
		    nread -= nwritten;
		    if (nread > 0)
			/* we're lazy... */
			memmove(buf, &buf[nwritten], nread);
		} else if (nwritten < 0) {
		    if (r->connection->aborted)
			break;
		    else if (errno == EAGAIN)
			continue;
		    else {
			ap_log_rerror(APLOG_MARK, APLOG_INFO, r,
			    "client stopped connection before send completed");
			ap_bsetflag(r->connection->client, B_EOUT, 1);
			r->connection->aborted = 1;
			break;
		    }
		}
	    }
	    ap_kill_timeout(r);
	    if (r->sent_bodyct)
		ap_bgetopt(r->connection->client, BO_BYTECT, &r->bytes_sent);
	}
    }
#ifdef PLAIN
#else
    BZ2_bzclose(zf);
#endif
    ap_pfclose(r->pool, f);

    return OK;
}

static const handler_rec bunzip2_handlers[] =
{
    {"send-bunzip2", bunzip2_handler},
    {"*/*", bunzip2_handler},
    {NULL}
};

module MODULE_VAR_EXPORT bunzip2_module =
{
    STANDARD_MODULE_STUFF,
    NULL,			/* initializer */
    NULL,			/* dir config creater */
    NULL,			/* dir merger --- default is to override */
    NULL,			/* server config */
    NULL,			/* merge server config */
    NULL,			/* command table */
    bunzip2_handlers,		/* handlers */
    NULL,			/* filename translation */
    NULL,			/* check_user_id */
    NULL,			/* check auth */
    NULL,			/* check access */
    NULL,			/* type_checker */
    NULL,			/* fixups */
    NULL,			/* logger */
    NULL,			/* header parser */
    NULL,			/* child_init */
    NULL,			/* child_exit */
    NULL			/* post read-request */
};