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authorXin Long <lucien.xin@gmail.com>2023-01-28 10:58:39 -0500
committerJakub Kicinski <kuba@kernel.org>2023-02-01 20:54:27 -0800
commitb1a78b9b98862cda167b643690e43662ea060625 (patch)
tree6a0ceb380c64d02b978f47debe65aef168d76d9b /net/ipv4
parent9eefedd58ae1daece2ba907849a44db2941fb4b0 (diff)
net: add support for ipv4 big tcp
Similar to Eric's IPv6 BIG TCP, this patch is to enable IPv4 BIG TCP. Firstly, allow sk->sk_gso_max_size to be set to a value greater than GSO_LEGACY_MAX_SIZE by not trimming gso_max_size in sk_trim_gso_size() for IPv4 TCP sockets. Then on TX path, set IP header tot_len to 0 when skb->len > IP_MAX_MTU in __ip_local_out() to allow to send BIG TCP packets, and this implies that skb->len is the length of a IPv4 packet; On RX path, use skb->len as the length of the IPv4 packet when the IP header tot_len is 0 and skb->len > IP_MAX_MTU in ip_rcv_core(). As the API iph_set_totlen() and skb_ip_totlen() are used in __ip_local_out() and ip_rcv_core(), we only need to update these APIs. Also in GRO receive, add the check for ETH_P_IP/IPPROTO_TCP, and allows the merged packet size >= GRO_LEGACY_MAX_SIZE in skb_gro_receive(). In GRO complete, set IP header tot_len to 0 when the merged packet size greater than IP_MAX_MTU in iph_set_totlen() so that it can be processed on RX path. Note that by checking skb_is_gso_tcp() in API iph_totlen(), it makes this implementation safe to use iph->len == 0 indicates IPv4 BIG TCP packets. Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/af_inet.c7
-rw-r--r--net/ipv4/ip_input.c2
-rw-r--r--net/ipv4/ip_output.c2
3 files changed, 6 insertions, 5 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 6c0ec2789943..2f992a323b95 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1485,6 +1485,7 @@ struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
if (unlikely(ip_fast_csum((u8 *)iph, 5)))
goto out;
+ NAPI_GRO_CB(skb)->proto = proto;
id = ntohl(*(__be32 *)&iph->id);
flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
id >>= 16;
@@ -1618,9 +1619,9 @@ int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
int inet_gro_complete(struct sk_buff *skb, int nhoff)
{
- __be16 newlen = htons(skb->len - nhoff);
struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
const struct net_offload *ops;
+ __be16 totlen = iph->tot_len;
int proto = iph->protocol;
int err = -ENOSYS;
@@ -1629,8 +1630,8 @@ int inet_gro_complete(struct sk_buff *skb, int nhoff)
skb_set_inner_network_header(skb, nhoff);
}
- csum_replace2(&iph->check, iph->tot_len, newlen);
- iph->tot_len = newlen;
+ iph_set_totlen(iph, skb->len - nhoff);
+ csum_replace2(&iph->check, totlen, iph->tot_len);
ops = rcu_dereference(inet_offloads[proto]);
if (WARN_ON(!ops || !ops->callbacks.gro_complete))
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index e880ce77322a..fe9ead9ee863 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -511,7 +511,7 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
goto csum_error;
- len = ntohs(iph->tot_len);
+ len = iph_totlen(skb, iph);
if (skb->len < len) {
drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
__IP_INC_STATS(net, IPSTATS_MIB_INTRUNCATEDPKTS);
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 922c87ef1ab5..4e4e308c3230 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -100,7 +100,7 @@ int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct iphdr *iph = ip_hdr(skb);
- iph->tot_len = htons(skb->len);
+ iph_set_totlen(iph, skb->len);
ip_send_check(iph);
/* if egress device is enslaved to an L3 master device pass the