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/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/rpl.h b/include/net/rpl.h
index 30fe780..7473419 100644 (file)
--- a/include/net/rpl.h
+++ b/include/net/rpl.h
@@ -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);

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index a543df5..65adc11 100644 (file)
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -517,11 +517,7 @@ looped_back:
 
                        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 @@ looped_back:
                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 @@ looped_back:
                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;
 

diff --git a/net/ipv6/rpl.c b/net/ipv6/rpl.c
index d1876f1..e186998 100644 (file)
--- a/net/ipv6/rpl.c
+++ b/net/ipv6/rpl.c
@@ -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)