httpheader.c

-

/*
 * $Id: HttpHeader.c,v 1.61.2.1 1999/02/12 19:38:18 wessels Exp $
 *
 * DEBUG: section 55    HTTP Header
 * AUTHOR: Alex Rousskov
 *
 * 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.
 *
 */

#include "squid.h"

/*
 * On naming conventions:
 * 
 * HTTP/1.1 defines message-header as 
 * 
 * message-header = field-name ":" [ field-value ] CRLF
 * field-name     = token
 * field-value    = *( field-content | LWS )
 * 
 * HTTP/1.1 does not give a name name a group of all message-headers in a message.
 * Squid 1.1 seems to refer to that group _plus_ start-line as "headers".
 * 
 * HttpHeader is an object that represents all message-headers in a message.
 * HttpHeader does not manage start-line.
 * 
 * HttpHeader is implemented as a collection of header "entries".
 * An entry is a (field_id, field_name, field_value) triplet.
 */


/*
 * local constants and vars
 */

/*
 * A table with major attributes for every known field. 
 * We calculate name lengths and reorganize this array on start up. 
 * After reorganization, field id can be used as an index to the table.
 */
static const HttpHeaderFieldAttrs HeadersAttrs[] =
{
    {"Accept", HDR_ACCEPT, ftStr},
    {"Accept-Charset", HDR_ACCEPT_CHARSET, ftStr},
    {"Accept-Encoding", HDR_ACCEPT_ENCODING, ftStr},
    {"Accept-Language", HDR_ACCEPT_LANGUAGE, ftStr},
    {"Accept-Ranges", HDR_ACCEPT_RANGES, ftStr},
    {"Age", HDR_AGE, ftInt},
    {"Allow", HDR_ALLOW, ftStr},
    {"Authorization", HDR_AUTHORIZATION, ftStr},	/* for now */
    {"Cache-Control", HDR_CACHE_CONTROL, ftPCc},
    {"Connection", HDR_CONNECTION, ftStr},
    {"Content-Base", HDR_CONTENT_BASE, ftStr},
    {"Content-Encoding", HDR_CONTENT_ENCODING, ftStr},
    {"Content-Language", HDR_CONTENT_LANGUAGE, ftStr},
    {"Content-Length", HDR_CONTENT_LENGTH, ftInt},
    {"Content-Location", HDR_CONTENT_LOCATION, ftStr},
    {"Content-MD5", HDR_CONTENT_MD5, ftStr},	/* for now */
    {"Content-Range", HDR_CONTENT_RANGE, ftPContRange},
    {"Content-Type", HDR_CONTENT_TYPE, ftStr},
    {"Date", HDR_DATE, ftDate_1123},
    {"ETag", HDR_ETAG, ftETag},
    {"Expires", HDR_EXPIRES, ftDate_1123},
    {"From", HDR_FROM, ftStr},
    {"Host", HDR_HOST, ftStr},
    {"If-Match", HDR_IF_MATCH, ftStr},	/* for now */
    {"If-Modified-Since", HDR_IF_MODIFIED_SINCE, ftDate_1123},
    {"If-None-Match", HDR_IF_NONE_MATCH, ftStr},	/* for now */
    {"If-Range", HDR_IF_RANGE, ftDate_1123_or_ETag},
    {"Last-Modified", HDR_LAST_MODIFIED, ftDate_1123},
    {"Link", HDR_LINK, ftStr},
    {"Location", HDR_LOCATION, ftStr},
    {"Max-Forwards", HDR_MAX_FORWARDS, ftInt},
    {"Mime-Version", HDR_MIME_VERSION, ftStr},	/* for now */
    {"Pragma", HDR_PRAGMA, ftStr},
    {"Proxy-Authenticate", HDR_PROXY_AUTHENTICATE, ftStr},
    {"Proxy-Authorization", HDR_PROXY_AUTHORIZATION, ftStr},
    {"Proxy-Connection", HDR_PROXY_CONNECTION, ftStr},
    {"Public", HDR_PUBLIC, ftStr},
    {"Range", HDR_RANGE, ftPRange},
    {"Referer", HDR_REFERER, ftStr},
    {"Request-Range", HDR_REQUEST_RANGE, ftPRange},	/* usually matches HDR_RANGE */
    {"Retry-After", HDR_RETRY_AFTER, ftStr},	/* for now (ftDate_1123 or ftInt!) */
    {"Server", HDR_SERVER, ftStr},
    {"Set-Cookie", HDR_SET_COOKIE, ftStr},
    {"Title", HDR_TITLE, ftStr},
    {"Upgrade", HDR_UPGRADE, ftStr},	/* for now */
    {"User-Agent", HDR_USER_AGENT, ftStr},
    {"Vary", HDR_VARY, ftStr},	/* for now */
    {"Via", HDR_VIA, ftStr},	/* for now */
    {"Warning", HDR_WARNING, ftStr},	/* for now */
    {"WWW-Authenticate", HDR_WWW_AUTHENTICATE, ftStr},
    {"X-Cache", HDR_X_CACHE, ftStr},
    {"X-Cache-Lookup", HDR_X_CACHE_LOOKUP, ftStr},
    {"X-Forwarded-For", HDR_X_FORWARDED_FOR, ftStr},
    {"X-Request-URI", HDR_X_REQUEST_URI, ftStr},
    {"X-Squid-Error", HDR_X_SQUID_ERROR, ftStr},
    {"Other:", HDR_OTHER, ftStr}	/* ':' will not allow matches */
};
static HttpHeaderFieldInfo *Headers = NULL;

/*
 * headers with field values defined as #(values) in HTTP/1.1
 * Headers that are currently not recognized, are commented out.
 */
static HttpHeaderMask ListHeadersMask;	/* set run-time using  ListHeadersArr */
static http_hdr_type ListHeadersArr[] =
{
    HDR_ACCEPT,
    HDR_ACCEPT_CHARSET, HDR_ACCEPT_ENCODING, HDR_ACCEPT_LANGUAGE,
    HDR_ACCEPT_RANGES, HDR_ALLOW,
    HDR_CACHE_CONTROL,
    HDR_CONTENT_ENCODING,
    HDR_CONTENT_LANGUAGE,
    HDR_CONNECTION,
    HDR_IF_MATCH, HDR_IF_NONE_MATCH,
    HDR_LINK, HDR_PRAGMA,
    /* HDR_TRANSFER_ENCODING, */
    HDR_UPGRADE,
    HDR_VARY,
    HDR_VIA,
    /* HDR_WARNING, */
    HDR_WWW_AUTHENTICATE,
    /* HDR_EXPECT, HDR_TE, HDR_TRAILER */
    HDR_X_FORWARDED_FOR
};

/* general-headers */
static http_hdr_type GeneralHeadersArr[] =
{
    HDR_CACHE_CONTROL, HDR_CONNECTION, HDR_DATE, HDR_PRAGMA,
    /* HDR_TRANSFER_ENCODING, */
    HDR_UPGRADE,
    /* HDR_TRAILER, */
    HDR_VIA
};

/* entity-headers */
static http_hdr_type EntityHeadersArr[] =
{
    HDR_ALLOW, HDR_CONTENT_BASE, HDR_CONTENT_ENCODING, HDR_CONTENT_LANGUAGE,
    HDR_CONTENT_LENGTH, HDR_CONTENT_LOCATION, HDR_CONTENT_MD5,
    HDR_CONTENT_RANGE, HDR_CONTENT_TYPE, HDR_ETAG, HDR_EXPIRES, HDR_LAST_MODIFIED, HDR_LINK,
    HDR_OTHER
};

static HttpHeaderMask ReplyHeadersMask;		/* set run-time using ReplyHeaders */
static http_hdr_type ReplyHeadersArr[] =
{
    HDR_ACCEPT, HDR_ACCEPT_CHARSET, HDR_ACCEPT_ENCODING, HDR_ACCEPT_LANGUAGE,
    HDR_ACCEPT_RANGES, HDR_AGE,
    HDR_LOCATION, HDR_MAX_FORWARDS,
    HDR_MIME_VERSION, HDR_PUBLIC, HDR_RETRY_AFTER, HDR_SERVER, HDR_SET_COOKIE,
    HDR_VARY,
    HDR_WARNING, HDR_PROXY_CONNECTION, HDR_X_CACHE,
    HDR_X_CACHE_LOOKUP,
    HDR_X_REQUEST_URI,
    HDR_X_SQUID_ERROR
};

static HttpHeaderMask RequestHeadersMask;	/* set run-time using RequestHeaders */
static http_hdr_type RequestHeadersArr[] =
{
    HDR_AUTHORIZATION, HDR_FROM, HDR_HOST,
    HDR_IF_MATCH, HDR_IF_MODIFIED_SINCE, HDR_IF_NONE_MATCH,
    HDR_IF_RANGE, HDR_MAX_FORWARDS, HDR_PROXY_CONNECTION,
    HDR_PROXY_AUTHORIZATION, HDR_RANGE, HDR_REFERER, HDR_REQUEST_RANGE,
    HDR_USER_AGENT, HDR_X_FORWARDED_FOR
};

/* header accounting */
static HttpHeaderStat HttpHeaderStats[] =
{
    {"all"},
#if USE_HTCP
    {"HTCP reply"},
#endif
    {"request"},
    {"reply"}
};
static int HttpHeaderStatCount = countof(HttpHeaderStats);

static int HeaderEntryParsedCount = 0;

/*
 * local routines
 */

#define assert_eid(id) assert((id) >= 0 && (id) < HDR_ENUM_END)

static HttpHeaderEntry *httpHeaderEntryCreate(http_hdr_type id, const char *name, const char *value);
static void httpHeaderEntryDestroy(HttpHeaderEntry * e);
static HttpHeaderEntry *httpHeaderEntryParseCreate(const char *field_start, const char *field_end);
static void httpHeaderNoteParsedEntry(http_hdr_type id, String value, int error);

static void httpHeaderStatInit(HttpHeaderStat * hs, const char *label);
static void httpHeaderStatDump(const HttpHeaderStat * hs, StoreEntry * e);

/*
 * Module initialization routines
 */

void
httpHeaderInitModule()
{
    int i;
    /* check that we have enough space for masks */
    assert(8 * sizeof(HttpHeaderMask) >= HDR_ENUM_END);
    /* all headers must be described */
    assert(countof(HeadersAttrs) == HDR_ENUM_END);
    if (!Headers)
	Headers = httpHeaderBuildFieldsInfo(HeadersAttrs, HDR_ENUM_END);
    /* create masks */
    httpHeaderMaskInit(&ListHeadersMask, 0);
    httpHeaderCalcMask(&ListHeadersMask, (const int *) ListHeadersArr, countof(ListHeadersArr));
    httpHeaderMaskInit(&ReplyHeadersMask, 0);
    httpHeaderCalcMask(&ReplyHeadersMask, (const int *) ReplyHeadersArr, countof(ReplyHeadersArr));
    httpHeaderCalcMask(&ReplyHeadersMask, (const int *) GeneralHeadersArr, countof(GeneralHeadersArr));
    httpHeaderCalcMask(&ReplyHeadersMask, (const int *) EntityHeadersArr, countof(EntityHeadersArr));
    httpHeaderMaskInit(&RequestHeadersMask, 0);
    httpHeaderCalcMask(&RequestHeadersMask, (const int *) RequestHeadersArr, countof(RequestHeadersArr));
    httpHeaderCalcMask(&RequestHeadersMask, (const int *) GeneralHeadersArr, countof(GeneralHeadersArr));
    httpHeaderCalcMask(&RequestHeadersMask, (const int *) EntityHeadersArr, countof(EntityHeadersArr));
    /* init header stats */
    assert(HttpHeaderStatCount == hoReply + 1);
    for (i = 0; i < HttpHeaderStatCount; i++)
	httpHeaderStatInit(HttpHeaderStats + i, HttpHeaderStats[i].label);
    HttpHeaderStats[hoRequest].owner_mask = &RequestHeadersMask;
    HttpHeaderStats[hoReply].owner_mask = &ReplyHeadersMask;
#if USE_HTCP
    HttpHeaderStats[hoHtcpReply].owner_mask = &ReplyHeadersMask;
#endif
    /* init dependent modules */
    httpHdrCcInitModule();
    /* register with cache manager */
    cachemgrRegister("http_headers",
	"HTTP Header Statistics", httpHeaderStoreReport, 0, 1);
}

void
httpHeaderCleanModule()
{
    httpHeaderDestroyFieldsInfo(Headers, HDR_ENUM_END);
    Headers = NULL;
    httpHdrCcCleanModule();
}

static void
httpHeaderStatInit(HttpHeaderStat * hs, const char *label)
{
    assert(hs);
    assert(label);
    memset(hs, 0, sizeof(HttpHeaderStat));
    hs->label = label;
    statHistEnumInit(&hs->hdrUCountDistr, 32);	/* not a real enum */
    statHistEnumInit(&hs->fieldTypeDistr, HDR_ENUM_END);
    statHistEnumInit(&hs->ccTypeDistr, CC_ENUM_END);
}

/*
 * HttpHeader Implementation
 */

void
httpHeaderInit(HttpHeader * hdr, http_hdr_owner_type owner)
{
    assert(hdr);
    assert(owner > hoNone && owner <= hoReply);
    debug(55, 7) ("init-ing hdr: %p owner: %d\n", hdr, owner);
    memset(hdr, 0, sizeof(*hdr));
    hdr->owner = owner;
    arrayInit(&hdr->entries);
}

void
httpHeaderClean(HttpHeader * hdr)
{
    HttpHeaderPos pos = HttpHeaderInitPos;
    HttpHeaderEntry *e;

    assert(hdr);
    assert(hdr->owner > hoNone && hdr->owner <= hoReply);
    debug(55, 7) ("cleaning hdr: %p owner: %d\n", hdr, hdr->owner);

    statHistCount(&HttpHeaderStats[hdr->owner].hdrUCountDistr, hdr->entries.count);
    HttpHeaderStats[hdr->owner].destroyedCount++;
    HttpHeaderStats[hdr->owner].busyDestroyedCount += hdr->entries.count > 0;
    while ((e = httpHeaderGetEntry(hdr, &pos))) {
	/* tmp hack to try to avoid coredumps */
	if (e->id < 0 || e->id >= HDR_ENUM_END) {
	    debug(55, 0) ("httpHeaderClean BUG: entry[%d] is invalid (%d). Ignored.\n",
		pos, e->id);
	} else {
	    statHistCount(&HttpHeaderStats[hdr->owner].fieldTypeDistr, e->id);
	    /* yes, this destroy() leaves us in an incosistent state */
	    httpHeaderEntryDestroy(e);
	}
    }
    arrayClean(&hdr->entries);
}

/* append entries (also see httpHeaderUpdate) */
void
httpHeaderAppend(HttpHeader * dest, const HttpHeader * src)
{
    const HttpHeaderEntry *e;
    HttpHeaderPos pos = HttpHeaderInitPos;
    assert(src && dest);
    assert(src != dest);
    debug(55, 7) ("appending hdr: %p += %p\n", dest, src);

    while ((e = httpHeaderGetEntry(src, &pos))) {
	httpHeaderAddEntry(dest, httpHeaderEntryClone(e));
    }
}

/* use fresh entries to replace old ones */
void
httpHeaderUpdate(HttpHeader * old, const HttpHeader * fresh, const HttpHeaderMask * denied_mask)
{
    const HttpHeaderEntry *e;
    HttpHeaderPos pos = HttpHeaderInitPos;
    assert(old && fresh);
    assert(old != fresh);
    debug(55, 7) ("updating hdr: %p <- %p\n", old, fresh);

    while ((e = httpHeaderGetEntry(fresh, &pos))) {
	/* deny bad guys (ok to check for HDR_OTHER) here */
	if (denied_mask && CBIT_TEST(*denied_mask, e->id))
	    continue;
	httpHeaderDelByName(old, strBuf(e->name));
	httpHeaderAddEntry(old, httpHeaderEntryClone(e));
    }
}

/* just handy in parsing: resets and returns false */
int