Commit ac9d8a66 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

ipv6: rpl: Remove pskb(_may)?_pull() in ipv6_rpl_srh_rcv(). 

As Eric Dumazet pointed out [0], ipv6_rthdr_rcv() pulls these data

  - Segment Routing Header : 8
  - Hdr Ext Len            : skb_transport_header(skb)[1] << 3

needed by ipv6_rpl_srh_rcv().  We can remove pskb_may_pull() and
replace pskb_pull() with skb_pull() in ipv6_rpl_srh_rcv().

Link: https://lore.kernel.org/netdev/CANn89iLboLwLrHXeHJucAqBkEL_S0rJFog68t7wwwXO-aNf5Mg@mail.gmail.com/

 [0]
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 9a94d764

include/net/rpl.h

+0 −3
Original line number Diff line number Diff line
@@ -23,9 +23,6 @@ static inline int rpl_init(void) 
static inline void rpl_exit(void) {}

#endif



size_t ipv6_rpl_srh_size(unsigned char n, unsigned char cmpri,

			 unsigned char cmpre);



void ipv6_rpl_srh_decompress(struct ipv6_rpl_sr_hdr *outhdr,

			     const struct ipv6_rpl_sr_hdr *inhdr,

			     const struct in6_addr *daddr, unsigned char n);

net/ipv6/exthdrs.c

+1 −16
Original line number Diff line number Diff line
@@ -517,11 +517,7 @@ static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 


			skb_postpull_rcsum(skb, skb_network_header(skb),

					   skb_network_header_len(skb));



			if (!pskb_pull(skb, offset)) {

				kfree_skb(skb);

				return -1;

			}

			skb_pull(skb, offset);

			skb_postpull_rcsum(skb, skb_transport_header(skb),

					   offset);
@@ -543,11 +539,6 @@ static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 
		return 1;

	}



	if (!pskb_may_pull(skb, sizeof(*hdr))) {

		kfree_skb(skb);

		return -1;

	}



	n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre);

	r = do_div(n, (16 - hdr->cmpri));

	/* checks if calculation was without remainder and n fits into
@@ -567,12 +558,6 @@ static int ipv6_rpl_srh_rcv(struct sk_buff *skb) 
		return -1;

	}



	if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri,

						  hdr->cmpre))) {

		kfree_skb(skb);

		return -1;

	}



	hdr->segments_left--;

	i = n - hdr->segments_left;

net/ipv6/rpl.c

+0 −7
Original line number Diff line number Diff line
@@ -29,13 +29,6 @@ static void *ipv6_rpl_segdata_pos(const struct ipv6_rpl_sr_hdr *hdr, int i) 
	return (void *)&hdr->rpl_segdata[i * IPV6_PFXTAIL_LEN(hdr->cmpri)];

}



size_t ipv6_rpl_srh_size(unsigned char n, unsigned char cmpri,

			 unsigned char cmpre)

{

	return sizeof(struct ipv6_rpl_sr_hdr) + (n * IPV6_PFXTAIL_LEN(cmpri)) +

		IPV6_PFXTAIL_LEN(cmpre);

}



void ipv6_rpl_srh_decompress(struct ipv6_rpl_sr_hdr *outhdr,

			     const struct ipv6_rpl_sr_hdr *inhdr,

			     const struct in6_addr *daddr, unsigned char n)