errorpage.c

-

/*
 * $Id: errorpage.c,v 1.148.2.2 1999/06/19 16:16:06 wessels Exp $
 *
 * DEBUG: section 4     Error Generation
 * AUTHOR: Duane Wessels
 *
 * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
 * ----------------------------------------------------------
 *
 *  Squid is the result of efforts by numerous individuals from the
 *  Internet community.  Development is led by Duane Wessels of the
 *  National Laboratory for Applied Network Research and funded by the
 *  National Science Foundation.  Squid is Copyrighted (C) 1998 by
 *  Duane Wessels and the University of California San Diego.  Please
 *  see the COPYRIGHT file for full details.  Squid incorporates
 *  software developed and/or copyrighted by other sources.  Please see
 *  the CREDITS file for full details.
 *
 *  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.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 */

/*
 * Abstract:  These routines are used to generate error messages to be
 *              sent to clients.  The error type is used to select between
 *              the various message formats. (formats are stored in the
 *              Config.errorDirectory)
 */

#include "squid.h"


/* local types */

typedef struct {
    int id;
    char *page_name;
} ErrorDynamicPageInfo;

/* local constant and vars */

static const char *const proxy_auth_challenge_fmt = "Basic realm=\"%s\"";

/*
 * note: hard coded error messages are not appended with %S automagically
 * to give you more control on the format
 */
static const struct {
    int type;			/* and page_id */
    const char *text;
} error_hard_text[] = {

    {
	ERR_SQUID_SIGNATURE,
	    "\n<br clear=\"all\">\n"
	    "<hr noshade size=1>\n"
	    "Generated %T by %h (<a href=\"http://squid.nlanr.net/Squid/\">%s</a>)\n"
	    "</BODY></HTML>\n"
    }
};

static Stack ErrorDynamicPages;

/* local prototypes */

static const int error_hard_text_count = sizeof(error_hard_text) / sizeof(*error_hard_text);
static char **error_text = NULL;
static int error_page_count = 0;

static char *errorTryLoadText(const char *page_name, const char *dir);
static char *errorLoadText(const char *page_name);
static const char *errorFindHardText(err_type type);
static ErrorDynamicPageInfo *errorDynamicPageInfoCreate(int id, const char *page_name);
static void errorDynamicPageInfoDestroy(ErrorDynamicPageInfo * info);
static MemBuf errorBuildContent(ErrorState * err);
static const char *errorConvert(char token, ErrorState * err);
static CWCB errorSendComplete;

/*
 * Function:  errorInitialize
 *
 * Abstract:  This function finds the error messages formats, and stores
 *            them in error_text[];
 *
 * Global effects:
 *            error_text[] - is modified
 */
void
errorInitialize(void)
{
    err_type i;
    const char *text;
    error_page_count = ERR_MAX + ErrorDynamicPages.count;
    error_text = xcalloc(error_page_count, sizeof(char *));
    for (i = ERR_NONE, i++; i < error_page_count; i++) {
	safe_free(error_text[i]);
	/* hard-coded ? */
	if ((text = errorFindHardText(i)))
	    error_text[i] = xstrdup(text);
	else if (i < ERR_MAX) {
	    /* precompiled ? */
	    error_text[i] = errorLoadText(err_type_str[i]);
	} else {
	    /* dynamic */
	    ErrorDynamicPageInfo *info = ErrorDynamicPages.items[i - ERR_MAX];
	    assert(info && info->id == i && info->page_name);
	    error_text[i] = errorLoadText(info->page_name);
	}
	assert(error_text[i]);
    }
}

void
errorClean(void)
{
    if (error_text) {
	int i;
	for (i = ERR_NONE + 1; i < error_page_count; i++)
	    safe_free(error_text[i]);
	safe_free(error_text);
    }
    while (ErrorDynamicPages.count)
	errorDynamicPageInfoDestroy(stackPop(&ErrorDynamicPages));
    error_page_count = 0;
}

static const char *
errorFindHardText(err_type type)
{
    int i;
    for (i = 0; i < error_hard_text_count; i++)
	if (error_hard_text[i].type == type)
	    return error_hard_text[i].text;
    return NULL;
}


static char *
errorLoadText(const char *page_name)
{
    /* test configured location */
    char *text = errorTryLoadText(page_name, Config.errorDirectory);
    /* test default location if failed */
    if (!text && strcmp(Config.errorDirectory, DEFAULT_SQUID_ERROR_DIR))
	text = errorTryLoadText(page_name, DEFAULT_SQUID_ERROR_DIR);
    /* giving up if failed */
    if (!text)
	fatal("failed to find or read error text file.");
    return text;
}

static char *
errorTryLoadText(const char *page_name, const char *dir)
{
    int fd;
    char path[MAXPATHLEN];
    struct stat sb;
    char *text;

    snprintf(path, sizeof(path), "%s/%s", dir, page_name);
    fd = file_open(path, O_RDONLY, NULL, NULL, NULL);
    if (fd < 0 || fstat(fd, &sb) < 0) {
	debug(4, 0) ("errorTryLoadText: '%s': %s\n", path, xstrerror());
	if (fd >= 0)
	    file_close(fd);
	return NULL;
    }
    text = xcalloc(sb.st_size + 2 + 1, 1);	/* 2 == space for %S */
    if (read(fd, text, sb.st_size) != sb.st_size) {
	debug(4, 0) ("errorTryLoadText: failed to fully read: '%s': %s\n",
	    path, xstrerror());
	xfree(text);
	text = NULL;
    }
    file_close(fd);
    if (strstr(text, "%s") == NULL)
	strcat(text, "%S");	/* add signature */
    return text;
}

static ErrorDynamicPageInfo *
errorDynamicPageInfoCreate(int id, const char *page_name)
{
    ErrorDynamicPageInfo *info = xcalloc(1, sizeof(ErrorDynamicPageInfo));
    info->id = id;
    info->page_name = xstrdup(page_name);
    return info;
}

static void
errorDynamicPageInfoDestroy(ErrorDynamicPageInfo * info)
{
    assert(info);
    xfree(info->page_name);
    xfree(info);
}

int
errorReservePageId(const char *page_name)
{
    ErrorDynamicPageInfo *info =
    errorDynamicPageInfoCreate(ERR_MAX + ErrorDynamicPages.count, page_name);
    stackPush(&ErrorDynamicPages, info);
    return info->id;
}

static const char *
errorPageName(int pageId)
{
    if (pageId >= ERR_NONE && pageId < ERR_MAX)		/* common case */
	return err_type_str[pageId];
    if (pageId >= ERR_MAX && pageId - ERR_MAX < ErrorDynamicPages.count)
	return ((ErrorDynamicPageInfo *) ErrorDynamicPages.
	    items[pageId - ERR_MAX])->page_name;
    return "ERR_UNKNOWN";	/* should not happen */
}

/*
 * Function:  errorCon
 *
 * Abstract:  This function creates a ErrorState object.
 */
ErrorState *
errorCon(err_type type, http_status status)
{
    ErrorState *err = memAllocate(MEM_ERRORSTATE);
    err->page_id = type;	/* has to be reset manually if needed */
    err->type = type;
    err->http_status = status;
    return err;
}

/*
 * Function:  errorAppendEntry
 *
 * Arguments: err - This object is destroyed after use in this function.
 *
 * Abstract:  This function generates a error page from the info contained
 *            by 'err' and then stores the text in the specified store
 *            entry.  This function should only be called by ``server
 *            side routines'' which need to communicate errors to the
 *            client side.  It should also be called from client_side.c
 *            because we now support persistent connections, and
 *            cannot assume that we can immediately write to the socket
 *            for an error.
 */
void
errorAppendEntry(StoreEntry * entry, ErrorState * err)
{
    HttpReply *rep;
    MemObject *mem = entry->mem_obj;
    assert(mem != NULL);
    assert(mem->inmem_hi == 0);
    if (entry->store_status != STORE_PENDING) {
	/*
	 * If the entry is not STORE_PENDING, then no clients
	 * care about it, and we don't need to generate an
	 * error message
	 */
	assert(EBIT_TEST(entry->flags, ENTRY_ABORTED));
	assert(mem->nclients == 0);
	errorStateFree(err);
	return;
    }
    storeLockObject(entry);
    storeBuffer(entry);
    rep = errorBuildReply(err);
    /* Add authentication header */
    switch (err->http_status) {
    case HTTP_PROXY_AUTHENTICATION_REQUIRED:
	/* Proxy authorisation needed */
	httpHeaderPutStrf(&rep->header, HDR_PROXY_AUTHENTICATE,
	    proxy_auth_challenge_fmt, Config.proxyAuthRealm);
	break;
    case HTTP_UNAUTHORIZED:
	/* WWW Authorisation needed */
	httpHeaderPutStrf(&rep->header, HDR_WWW_AUTHENTICATE,
	    proxy_auth_challenge_fmt, Config.proxyAuthRealm);
	break;
    default:
	/* Keep GCC happy */
	break;
    }
    httpReplySwapOut(rep, entry);
    httpReplyDestroy(rep);
    mem->reply->sline.status = err->http_status;
    mem->reply->content_length = -1;
    EBIT_CLR(entry->flags, ENTRY_FWD_HDR_WAIT);
    storeBufferFlush(entry);
    storeComplete(entry);