diff options
Diffstat (limited to 'net/ipv6/ip6_output.c')
| -rw-r--r-- | net/ipv6/ip6_output.c | 68 |
1 files changed, 50 insertions, 18 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 9cbf176..ae9f6d4 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1194,6 +1194,29 @@ 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, @@ -1203,7 +1226,7 @@ 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 hh_len; @@ -1260,8 +1283,12 @@ 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.path); + 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; @@ -1356,38 +1383,43 @@ 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; else alloclen = datalen + fragheaderlen; - /* - * 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. |