- if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
- unsigned int maxnonfragsize, headersize;
-
- headersize = sizeof(struct ipv6hdr) +
- (opt ? opt->opt_flen + opt->opt_nflen : 0) +
- (dst_allfrag(&rt->dst) ?
- sizeof(struct frag_hdr) : 0) +
- rt->rt6i_nfheader_len;
-
- if (ip6_sk_ignore_df(sk))
- maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
- else
- maxnonfragsize = mtu;
+ headersize = sizeof(struct ipv6hdr) +
+ (opt ? opt->opt_flen + opt->opt_nflen : 0) +
+ (dst_allfrag(&rt->dst) ?
+ sizeof(struct frag_hdr) : 0) +
+ rt->rt6i_nfheader_len;
+
+ if (cork->length + length > mtu - headersize && dontfrag &&
+ (sk->sk_protocol == IPPROTO_UDP ||
+ sk->sk_protocol == IPPROTO_RAW)) {
+ ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
+ sizeof(struct ipv6hdr));
+ goto emsgsize;
+ }