/* Distributed Checksum Clearinghouse
 *
 * build and parse headers
 *
 * Copyright (c) 2006 by Rhyolite Software, LLC
 *
 * This agreement is not applicable to any entity which sells anti-spam
 * solutions to others or provides an anti-spam solution as part of a
 * security solution sold to other entities, or to a private network
 * which employs the DCC or uses data provided by operation of the DCC
 * but does not provide corresponding data to other users.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * Parties not eligible to receive a license under this agreement can
 * obtain a commercial license to use DCC and permission to use
 * U.S. Patent 6,330,590 by contacting Commtouch at http://www.commtouch.com/
 * or by email to nospam@commtouch.com.
 *
 * A commercial license would be for Distributed Checksum and Reputation
 * Clearinghouse software.  That software includes additional features.  This
 * free license for Distributed ChecksumClearinghouse Software does not in any
 * way grant permision to use Distributed Checksum and Reputation Clearinghouse
 * software
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND RHYOLITE SOFTWARE, LLC DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL RHYOLITE SOFTWARE, LLC
 * BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 *
 * Rhyolite Software DCC 1.3.50-1.34 $Revision$
 */

#include "dcc_clnt.h"
#include "dcc_xhdr.h"


/* add text to the growing X-DCC header line */
void
dcc_add_header(DCC_HEADER_BUF *hdr, const char *p, ...)
{
	char *hp;
	u_int lim, n;
	va_list args;

	lim = sizeof(hdr->buf) - hdr->used;
	if (lim <= 0)
		return;
	hp = &hdr->buf[hdr->used];
	if (*(hp-1) == '\n') {
		*(hp-1) = ' ';
		++hdr->col;
	}
	va_start(args, p);
	n = vsnprintf(hp, lim, p, args);
	va_end(args);
	if (n >= lim-3) {
		dcc_error_msg("header buffer too small");
		hdr->buf[lim-1] = '\n';
		hdr->used = sizeof(hdr->buf);
		return;
	}
	hdr->col += n;
	hp[n++] = '\n';
	hp[n] = '\0';
	hdr->used += n;

	/* follow RFC 2822 and limit lines to 78 */
	if (hdr->col > DCC_MAX_HDR_LINE	/* if pushed past line end, */
	    && *(hp-1) == ' '		/* & not the first cksum report, */
	    && hdr->used < sizeof(hdr->buf)-2) {    /* & have space */
		memmove(hp+1, hp, n+1);	/* then break the line */
		*(hp-1) = '\n';
		*hp = '\t';
		hdr->col = n+8;
		++hdr->used;
	}
}



int
dcc_xhdr_start(char *xhdr, int xhdr_len, const DCC_CLNT_INFO *info)
{
	int inx, i;
	const char *brand;

	if (!info
	    || (inx = info->dcc.act_inx) >= info->dcc.num_addrs) {
		brand = "";
		i = 0;
	} else {
		brand = info->dcc.addrs[inx].brand;
		i = xhdr_len-sizeof(DCC_XHDR_START);
		if (i < 0)
			i = 0;
		if (i > ISZ(DCC_BRAND))
			i = ISZ(DCC_BRAND);
	}

	i = snprintf(xhdr, xhdr_len, DCC_XHDR_START"%.*s-Metrics", i, brand);
	if (i >= xhdr_len)
		i = xhdr_len-1;
	return i;
}



void
dcc_header_init(DCC_HEADER_BUF *hdr, DCC_SRVR_ID srvr_id)
{
	if (srvr_id < DCC_SRVR_ID_MIN || srvr_id > DCC_SRVR_ID_MAX) {
		hdr->used = dcc_xhdr_start(hdr->buf, sizeof(hdr->buf)-8,
					   0);
	} else {
		hdr->used = dcc_xhdr_start(hdr->buf, sizeof(hdr->buf)-8,
					   dcc_clnt_info);
	}
	hdr->col = hdr->used;
	hdr->start_len = hdr->used;

	dcc_add_header(hdr, ": %s %d;", dcc_clnt_hostname, srvr_id);
}



/* add a checksum and its counts to a growing X-DCC-Warning header line */
void
dcc_add_header_ck(DCC_HEADER_BUF *hdr,
		  DCC_CK_TYPES type,	/* which kind of checksum */
		  DCC_TGTS tgts)
{
	char tbuf[30], ckcnt[10];

	dcc_add_header(hdr, "%s=%s",
		       dcc_type2str(tbuf, sizeof(tbuf), type, 0, 0, 0),
		       dcc_tgts2str(ckcnt, sizeof(ckcnt), tgts, 0));
}



/* write header with lines ending with either "\n" or "\r\n"
 *	the buffer must already contain '\n' as needed */
void
dcc_write_header(LOG_WRITE_FNC fnc, void *wctxt,
		 const char *hdr, int hdr_len,
		 u_char crlf)		/* 1=use "\r\n" instead of "\n" */
{
	char c;
	int i;

	if (hdr_len == 0)
		return;

	i = 0;
	for (;;) {
		c = hdr[i];
		if (c == '\n' && crlf) {
			if (i != 0)
				fnc(wctxt, hdr, i);
			fnc(wctxt, "\r\n", 2);
			++i;
			hdr += i;
			hdr_len -= i;
			if (hdr_len <= 0)
				return;
			i = 0;
			continue;
		}
		if (++i >= hdr_len) {
			fnc(wctxt, hdr, i);
			return;
		}
	}
}



/* create an X-DCC header for a whitelist mail message */
void
dcc_header_white(DCC_HEADER_BUF *hdr)
{
	hdr->col = hdr->used;
	hdr->start_len = hdr->used;

	hdr->used = dcc_xhdr_start(hdr->buf, sizeof(hdr->buf)-8, 0);
	dcc_add_header(hdr, ": %s; "DCC_XHDR_WHITELIST, dcc_clnt_hostname);
}