Commit 04910265 authored by Tomasz Grobelny's avatar Tomasz Grobelny Committed by Gerrit Renker
Browse files

dccp qpolicy: Parameter checking of cmsg qpolicy parameters 



Ensure that cmsg->cmsg_type value is valid for qpolicy
that is currently in use.

Signed-off-by: default avatarTomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
parent 871a2c16

net/dccp/dccp.h

+1 −0
Original line number Diff line number Diff line
@@ -251,6 +251,7 @@ extern bool dccp_qpolicy_full(struct sock *sk); 
extern void		dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb);

extern struct sk_buff	*dccp_qpolicy_top(struct sock *sk);

extern struct sk_buff	*dccp_qpolicy_pop(struct sock *sk);

extern bool		dccp_qpolicy_param_ok(struct sock *sk, __be32 param);



/*

 * TX Packet Output and TX Timers

net/dccp/proto.c

+4 −0
Original line number Diff line number Diff line
@@ -726,6 +726,10 @@ static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) 
		if (cmsg->cmsg_level != SOL_DCCP)

			continue;



		if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&

		    !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))

			return -EINVAL;



		switch (cmsg->cmsg_type) {

		case DCCP_SCM_PRIORITY:

			if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))

net/dccp/qpolicy.c

+17 −6
Original line number Diff line number Diff line
@@ -73,17 +73,20 @@ static struct dccp_qpolicy_operations { 
	void		(*push)	(struct sock *sk, struct sk_buff *skb);

	bool		(*full) (struct sock *sk);

	struct sk_buff*	(*top)  (struct sock *sk);

	__be32		params;



} qpol_table[DCCPQ_POLICY_MAX] = {

	[DCCPQ_POLICY_SIMPLE] = {

		.push   = qpolicy_simple_push,

		.full   = qpolicy_simple_full,

		.top    = qpolicy_simple_top,

		.params = 0,

	},

	[DCCPQ_POLICY_PRIO] = {

		.push   = qpolicy_simple_push,

		.full   = qpolicy_prio_full,

		.top    = qpolicy_prio_best_skb,

		.params = DCCP_SCM_PRIORITY,

	},

};
@@ -124,3 +127,11 @@ struct sk_buff *dccp_qpolicy_pop(struct sock *sk) 
	}

	return skb;

}



bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param)

{

	/* check if exactly one bit is set */

	if (!param || (param & (param - 1)))

		return false;

	return (qpol_table[dccp_sk(sk)->dccps_qpolicy].params & param) == param;

}