summaryrefslogtreecommitdiffstats
path: root/net/ipv6/ip6_output.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv6/ip6_output.c')
-rw-r--r--net/ipv6/ip6_output.c68
1 files changed, 50 insertions, 18 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index b7ca461..13e5399 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1181,6 +1181,29 @@ static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
}
+static void ip6_append_data_mtu(int *mtu,
+ int *maxfraglen,
+ unsigned int fragheaderlen,
+ struct sk_buff *skb,
+ struct rt6_info *rt)
+{
+ if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
+ if (skb == NULL) {
+ /* first fragment, reserve header_len */
+ *mtu = *mtu - rt->dst.header_len;
+
+ } else {
+ /*
+ * this fragment is not first, the headers
+ * space is regarded as data space.
+ */
+ *mtu = dst_mtu(rt->dst.path);
+ }
+ *maxfraglen = ((*mtu - fragheaderlen) & ~7)
+ + fragheaderlen - sizeof(struct frag_hdr);
+ }
+}
+
int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
int offset, int len, int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen,
@@ -1190,7 +1213,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_cork *cork;
- struct sk_buff *skb;
+ struct sk_buff *skb, *skb_prev = NULL;
unsigned int maxfraglen, fragheaderlen;
int exthdrlen;
int dst_exthdrlen;
@@ -1248,8 +1271,12 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
inet->cork.fl.u.ip6 = *fl6;
np->cork.hop_limit = hlimit;
np->cork.tclass = tclass;
- mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
- rt->dst.dev->mtu : dst_mtu(&rt->dst);
+ if (rt->dst.flags & DST_XFRM_TUNNEL)
+ mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
+ rt->dst.dev->mtu : dst_mtu(&rt->dst);
+ else
+ mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
+ rt->dst.dev->mtu : dst_mtu(rt->dst.path);
if (np->frag_size < mtu) {
if (np->frag_size)
mtu = np->frag_size;
@@ -1345,25 +1372,27 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
unsigned int fraglen;
unsigned int fraggap;
unsigned int alloclen;
- struct sk_buff *skb_prev;
alloc_new_skb:
- skb_prev = skb;
-
/* There's no room in the current skb */
- if (skb_prev)
- fraggap = skb_prev->len - maxfraglen;
+ if (skb)
+ fraggap = skb->len - maxfraglen;
else
fraggap = 0;
+ /* update mtu and maxfraglen if necessary */
+ if (skb == NULL || skb_prev == NULL)
+ ip6_append_data_mtu(&mtu, &maxfraglen,
+ fragheaderlen, skb, rt);
+
+ skb_prev = skb;
/*
* If remaining data exceeds the mtu,
* we know we need more fragment(s).
*/
datalen = length + fraggap;
- if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
- datalen = maxfraglen - fragheaderlen;
- fraglen = datalen + fragheaderlen;
+ if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
+ datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
if ((flags & MSG_MORE) &&
!(rt->dst.dev->features&NETIF_F_SG))
alloclen = mtu;
@@ -1372,13 +1401,16 @@ alloc_new_skb:
alloclen += dst_exthdrlen;
- /*
- * The last fragment gets additional space at tail.
- * Note: we overallocate on fragments with MSG_MODE
- * because we have no idea if we're the last one.
- */
- if (datalen == length + fraggap)
- alloclen += rt->dst.trailer_len;
+ if (datalen != length + fraggap) {
+ /*
+ * this is not the last fragment, the trailer
+ * space is regarded as data space.
+ */
+ datalen += rt->dst.trailer_len;
+ }
+
+ alloclen += rt->dst.trailer_len;
+ fraglen = datalen + fragheaderlen;
/*
* We just reserve space for fragment header.