diff options
| -rw-r--r-- | include/net/ip.h | 9 | ||||
| -rw-r--r-- | include/uapi/linux/in.h | 4 | ||||
| -rw-r--r-- | net/ipv4/ip_output.c | 9 | ||||
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 2 |
4 files changed, 16 insertions, 8 deletions
diff --git a/include/net/ip.h b/include/net/ip.h index 4aa781b7f60..b885d75cede 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -266,7 +266,8 @@ int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) static inline bool ip_sk_accept_pmtu(const struct sock *sk) { - return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE; + return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE && + inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT; } static inline bool ip_sk_use_pmtu(const struct sock *sk) @@ -274,6 +275,12 @@ static inline bool ip_sk_use_pmtu(const struct sock *sk) return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE; } +static inline bool ip_sk_local_df(const struct sock *sk) +{ + return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO || + inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT; +} + static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, bool forwarding) { diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h index 393c5de09d4..c33a65e3d62 100644 --- a/include/uapi/linux/in.h +++ b/include/uapi/linux/in.h @@ -120,6 +120,10 @@ struct in_addr { * this socket to prevent accepting spoofed ones. */ #define IP_PMTUDISC_INTERFACE 4 +/* weaker version of IP_PMTUDISC_INTERFACE, which allos packets to get + * fragmented if they exeed the interface mtu + */ +#define IP_PMTUDISC_OMIT 5 #define IP_MULTICAST_IF 32 #define IP_MULTICAST_TTL 33 diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 22aa11971ed..e85445b2b10 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -824,8 +824,7 @@ static int __ip_append_data(struct sock *sk, fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; - maxnonfragsize = (inet->pmtudisc >= IP_PMTUDISC_DO) ? - mtu : 0xFFFF; + maxnonfragsize = ip_sk_local_df(sk) ? 0xFFFF : mtu; if (cork->length + length > maxnonfragsize - fragheaderlen) { ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, @@ -1148,8 +1147,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; - maxnonfragsize = (inet->pmtudisc >= IP_PMTUDISC_DO) ? - mtu : 0xFFFF; + maxnonfragsize = ip_sk_local_df(sk) ? 0xFFFF : mtu; if (cork->length + size > maxnonfragsize - fragheaderlen) { ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, @@ -1310,8 +1308,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, * to fragment the frame generated here. No matter, what transforms * how transforms change size of the packet, it will come out. */ - if (inet->pmtudisc < IP_PMTUDISC_DO) - skb->local_df = 1; + skb->local_df = ip_sk_local_df(sk); /* DF bit is set when we want to see DF on outgoing frames. * If local_df is set too, we still allow to fragment this frame diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 0968b28c4cf..64741b93863 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -643,7 +643,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, inet->nodefrag = val ? 1 : 0; break; case IP_MTU_DISCOVER: - if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_INTERFACE) + if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT) goto e_inval; inet->pmtudisc = val; break; |