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Message-Id: <1584524612-24470-6-git-send-email-ilpo.jarvinen@helsinki.fi>
Date: Wed, 18 Mar 2020 11:43:09 +0200
From: Ilpo Järvinen <ilpo.jarvinen@...sinki.fi>
To: netdev@...r.kernel.org
Cc: Yuchung Cheng <ycheng@...gle.com>,
Neal Cardwell <ncardwell@...gle.com>,
Eric Dumazet <eric.dumazet@...il.com>,
Olivier Tilmans <olivier.tilmans@...ia-bell-labs.com>
Subject: [RFC PATCH 05/28] tcp: extend TCP flags to allow AE bit/ACE field
From: Ilpo Järvinen <ilpo.jarvinen@...helsinki.fi>
With AccECN, there's one additional TCP flag to be used (AE)
and ACE field that overloads the definition of AE, CWR, and
ECE flags. As tcp_flags was previously only 1 byte, the
byte-order stuff needs to be added to it's handling.
Reorganize the bitfields to not enlarge the structure.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...helsinki.fi>
---
include/net/tcp.h | 13 ++++++++-----
include/uapi/linux/tcp.h | 9 ++++++---
net/ipv4/tcp_input.c | 3 ++-
net/ipv4/tcp_ipv4.c | 3 ++-
net/ipv4/tcp_output.c | 4 ++--
net/ipv6/tcp_ipv6.c | 3 ++-
net/netfilter/nf_log_common.c | 4 +++-
7 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index b97af0ff118f..6b6a1b8b3c6e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -791,7 +791,10 @@ static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb)
#define TCPHDR_URG 0x20
#define TCPHDR_ECE 0x40
#define TCPHDR_CWR 0x80
+#define TCPHDR_AE 0x100
+#define TCPHDR_FLAGS_MASK 0x1ff
+#define TCPHDR_ACE (TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE)
#define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR)
/* This is what the send packet queuing engine uses to pass
@@ -816,7 +819,11 @@ struct tcp_skb_cb {
u16 tcp_gso_size;
};
};
- __u8 tcp_flags; /* TCP header flags. (tcp[13]) */
+ __u16 tcp_flags:9, /* TCP header flags. (tcp[12-13]) */
+ unused:4,
+ txstamp_ack:1, /* Record TX timestamp for ack? */
+ eor:1, /* Is skb MSG_EOR marked? */
+ has_rxtstamp:1; /* SKB has a RX timestamp */
__u8 sacked; /* State flags for SACK. */
#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
@@ -829,10 +836,6 @@ struct tcp_skb_cb {
TCPCB_REPAIRED)
__u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */
- __u8 txstamp_ack:1, /* Record TX timestamp for ack? */
- eor:1, /* Is skb MSG_EOR marked? */
- has_rxtstamp:1, /* SKB has a RX timestamp */
- unused:5;
__u32 ack_seq; /* Sequence number ACK'd */
union {
struct {
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 1a7fc856e237..7a4bb72d7074 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -28,7 +28,8 @@ struct tcphdr {
__be32 seq;
__be32 ack_seq;
#if defined(__LITTLE_ENDIAN_BITFIELD)
- __u16 res1:4,
+ __u16 ae:1,
+ res1:3,
doff:4,
fin:1,
syn:1,
@@ -40,7 +41,8 @@ struct tcphdr {
cwr:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u16 doff:4,
- res1:4,
+ res1:3,
+ ae:1,
cwr:1,
ece:1,
urg:1,
@@ -70,6 +72,7 @@ union tcp_word_hdr {
#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
enum {
+ TCP_FLAG_AE = __constant_cpu_to_be32(0x01000000),
TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000),
TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000),
TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000),
@@ -78,7 +81,7 @@ enum {
TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000),
TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000),
TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000),
- TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000),
+ TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0E000000),
TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000)
};
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 7c444541cefd..e49a6f7ad5ce 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6473,7 +6473,8 @@ static void tcp_ecn_create_request(struct request_sock *req,
ecn_ok_dst = dst_feature(dst, DST_FEATURE_ECN_MASK);
ecn_ok = net->ipv4.sysctl_tcp_ecn || ecn_ok_dst;
- if (((!ect || th->res1) && ecn_ok) || tcp_ca_needs_ecn(listen_sk) ||
+ if (((!ect || th->res1 || th->ae) && ecn_ok) ||
+ tcp_ca_needs_ecn(listen_sk) ||
(ecn_ok_dst & DST_FEATURE_ECN_CA) ||
tcp_bpf_ca_needs_ecn((struct sock *)req))
inet_rsk(req)->ecn_ok = 1;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 52acf0bc2ee5..f18a2fbf2761 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1850,7 +1850,8 @@ static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph,
TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
skb->len - th->doff * 4);
TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
- TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
+ TCP_SKB_CB(skb)->tcp_flags = ntohs(*(__be16 *)&tcp_flag_word(th)) &
+ TCPHDR_FLAGS_MASK;
TCP_SKB_CB(skb)->tcp_tw_isn = 0;
TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
TCP_SKB_CB(skb)->sacked = 0;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 306e25d743e8..dc225e616f98 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -389,7 +389,7 @@ static void tcp_ecn_send(struct sock *sk, struct sk_buff *skb,
/* Constructs common control bits of non-data skb. If SYN/FIN is present,
* auto increment end seqno.
*/
-static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
+static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u16 flags)
{
skb->ip_summed = CHECKSUM_PARTIAL;
@@ -1167,7 +1167,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
th->seq = htonl(tcb->seq);
th->ack_seq = htonl(rcv_nxt);
*(((__be16 *)th) + 6) = htons(((tcp_header_size >> 2) << 12) |
- tcb->tcp_flags);
+ (tcb->tcp_flags & TCPHDR_FLAGS_MASK));
th->check = 0;
th->urg_ptr = 0;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index eaf09e6b7844..73032cd261ea 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1528,7 +1528,8 @@ static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
skb->len - th->doff*4);
TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
- TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
+ TCP_SKB_CB(skb)->tcp_flags = ntohs(*(__be16 *)&tcp_flag_word(th)) &
+ TCPHDR_FLAGS_MASK;
TCP_SKB_CB(skb)->tcp_tw_isn = 0;
TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
TCP_SKB_CB(skb)->sacked = 0;
diff --git a/net/netfilter/nf_log_common.c b/net/netfilter/nf_log_common.c
index ae5628ddbe6d..1457ead432eb 100644
--- a/net/netfilter/nf_log_common.c
+++ b/net/netfilter/nf_log_common.c
@@ -84,7 +84,9 @@ int nf_log_dump_tcp_header(struct nf_log_buf *m, const struct sk_buff *skb,
/* Max length: 9 "RES=0x3C " */
nf_log_buf_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) &
TCP_RESERVED_BITS) >> 22));
- /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
+ /* Max length: 35 "AE CWR ECE URG ACK PSH RST SYN FIN " */
+ if (th->ae)
+ nf_log_buf_add(m, "AE ");
if (th->cwr)
nf_log_buf_add(m, "CWR ");
if (th->ece)
--
2.20.1
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