RTAX_FEATURE_ALLFRAG was added before the first git commit:
https://www.mail-archive.com/bk-commits-head@vger.kernel.org/msg03399.html
The feature would send packets to the fragmentation path if a box
receives a PMTU value with less than 1280 byte. However, since commit
9d289715eb5c ("ipv6: stop sending PTB packets for MTU < 1280"), such
message would be simply discarded. The feature flag is neither supported
in iproute2 utility. In theory one can still manipulate it with direct
netlink message, but it is not ideal because it was based on obsoleted
guidance of RFC-2460 (replaced by RFC-8200).
The feature would always test false at the moment, so remove related
code or mark them as unused.
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/d78e44dcd9968a252143ffe78460446476a472a1.1698156966.git.yan@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
return msecs_to_jiffies(dst_metric(dst, metric));
}
-static inline u32
-dst_allfrag(const struct dst_entry *dst)
-{
- int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
- return ret;
-}
-
static inline int
dst_metric_locked(const struct dst_entry *dst, int metric)
{
struct request_sock *req_unhash,
bool *own_req);
u16 net_header_len;
- u16 net_frag_header_len;
u16 sockaddr_len;
int (*setsockopt)(struct sock *sk, int level, int optname,
sockptr_t optval, unsigned int optlen);
};
#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
-#define IPCORK_ALLFRAG 2 /* always fragment (for ipv6 for now) */
enum {
INET_FLAGS_PKTINFO = 0,
#define RTAX_FEATURE_ECN (1 << 0)
#define RTAX_FEATURE_SACK (1 << 1) /* unused */
#define RTAX_FEATURE_TIMESTAMP (1 << 2) /* unused */
-#define RTAX_FEATURE_ALLFRAG (1 << 3)
+#define RTAX_FEATURE_ALLFRAG (1 << 3) /* unused */
#define RTAX_FEATURE_TCP_USEC_TS (1 << 4)
#define RTAX_FEATURE_MASK (RTAX_FEATURE_ECN | \
*/
mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
- /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
- if (icsk->icsk_af_ops->net_frag_header_len) {
- const struct dst_entry *dst = __sk_dst_get(sk);
-
- if (dst && dst_allfrag(dst))
- mss_now -= icsk->icsk_af_ops->net_frag_header_len;
- }
-
/* Clamp it (mss_clamp does not include tcp options) */
if (mss_now > tp->rx_opt.mss_clamp)
mss_now = tp->rx_opt.mss_clamp;
{
const struct tcp_sock *tp = tcp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
- int mtu;
- mtu = mss +
+ return mss +
tp->tcp_header_len +
icsk->icsk_ext_hdr_len +
icsk->icsk_af_ops->net_header_len;
-
- /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
- if (icsk->icsk_af_ops->net_frag_header_len) {
- const struct dst_entry *dst = __sk_dst_get(sk);
-
- if (dst && dst_allfrag(dst))
- mtu += icsk->icsk_af_ops->net_frag_header_len;
- }
- return mtu;
}
EXPORT_SYMBOL(tcp_mss_to_mtu);
return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu);
if ((skb->len > mtu && !skb_is_gso(skb)) ||
- dst_allfrag(skb_dst(skb)) ||
(IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
return ip6_fragment(net, sk, skb, ip6_finish_output2);
else
return err;
fail_toobig:
- if (skb->sk && dst_allfrag(skb_dst(skb)))
- sk_gso_disable(skb->sk);
-
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
err = -EMSGSIZE;
cork->base.mark = ipc6->sockc.mark;
sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
- if (dst_allfrag(xfrm_dst_path(&rt->dst)))
- cork->base.flags |= IPCORK_ALLFRAG;
cork->base.length = 0;
-
cork->base.transmit_time = ipc6->sockc.transmit_time;
return 0;
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 (mtu <= fragheaderlen ||
while (length > 0) {
/* Check if the remaining data fits into current packet. */
- copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
+ copy = (cork->length <= mtu ? mtu : maxfraglen) - skb->len;
if (copy < length)
copy = maxfraglen - skb->len;
*/
datalen = length + fraggap;
- if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
+ if (datalen > (cork->length <= mtu ? mtu : maxfraglen) - fragheaderlen)
datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
fraglen = datalen + fragheaderlen;
pagedlen = 0;
struct dst_entry *dst = cork->base.dst;
cork->base.dst = NULL;
- cork->base.flags &= ~IPCORK_ALLFRAG;
skb_dst_set(skb, dst);
}
if (cork->base.dst) {
dst_release(cork->base.dst);
cork->base.dst = NULL;
- cork->base.flags &= ~IPCORK_ALLFRAG;
}
}
.conn_request = tcp_v6_conn_request,
.syn_recv_sock = tcp_v6_syn_recv_sock,
.net_header_len = sizeof(struct ipv6hdr),
- .net_frag_header_len = sizeof(struct frag_hdr),
.setsockopt = ipv6_setsockopt,
.getsockopt = ipv6_getsockopt,
.addr2sockaddr = inet6_csk_addr2sockaddr,
return -EMSGSIZE;
}
- if (toobig || dst_allfrag(skb_dst(skb)))
+ if (toobig)
return ip6_fragment(net, sk, skb,
__xfrm6_output_finish);
subflow_v6m_specific.send_check = ipv4_specific.send_check;
subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len;
subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced;
- subflow_v6m_specific.net_frag_header_len = 0;
subflow_v6m_specific.rebuild_header = subflow_rebuild_header;
tcpv6_prot_override = tcpv6_prot;