Commit 4c20c333 authored by David Howells's avatar David Howells
Browse files

rxrpc: Make the parsing of xdr payloads more coherent 



Make the parsing of xdr-encoded payloads, as passed to add_key, more
coherent.  Shuttling back and forth between various variables was a bit
hard to follow.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent d5953f65

net/rxrpc/key.c

+11 −10
Original line number Diff line number Diff line
@@ -135,7 +135,7 @@ static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep, 
 */

static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)

{

	const __be32 *xdr = prep->data, *token;

	const __be32 *xdr = prep->data, *token, *p;

	const char *cp;

	unsigned int len, paddedlen, loop, ntoken, toklen, sec_ix;

	size_t datalen = prep->datalen;
@@ -189,20 +189,20 @@ static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep) 
		goto not_xdr;



	/* check each token wrapper */

	token = xdr;

	p = xdr;

	loop = ntoken;

	do {

		if (datalen < 8)

			goto not_xdr;

		toklen = ntohl(*xdr++);

		sec_ix = ntohl(*xdr);

		toklen = ntohl(*p++);

		sec_ix = ntohl(*p);

		datalen -= 4;

		_debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);

		paddedlen = (toklen + 3) & ~3;

		if (toklen < 20 || toklen > datalen || paddedlen > datalen)

			goto not_xdr;

		datalen -= paddedlen;

		xdr += paddedlen >> 2;

		p += paddedlen >> 2;



	} while (--loop > 0);
@@ -214,17 +214,18 @@ static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep) 
	 * - we ignore the cellname, relying on the key to be correctly named

	 */

	do {

		xdr = token;

		toklen = ntohl(*xdr++);

		token = xdr + ((toklen + 3) >> 2);

		sec_ix = ntohl(*xdr++);

		token = xdr;

		xdr += (toklen + 3) / 4;



		sec_ix = ntohl(*token++);

		toklen -= 4;



		_debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);

		_debug("TOKEN type=%x len=%x", sec_ix, toklen);



		switch (sec_ix) {

		case RXRPC_SECURITY_RXKAD:

			ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);

			ret = rxrpc_preparse_xdr_rxkad(prep, datalen, token, toklen);

			if (ret != 0)

				goto error;

			break;