protocol: drop support for kernels older than 6.1

Upstream is now at 6.16, and maintaining compatibility with older
kernels adds unnecessary complexity. Remove support for < 6.1 to
simplify the codebase.

Meanwhile, add some missing LINUX_VERSION_CODE checks.

Signed-off-by: Xin Long <lucien.xin@gmail.com>

Author: lxin

README.md

@@ -110,7 +110,7 @@ in [ktls-utils](https://github.com/oracle/ktls-utils) will handle the handshake
 
 Both QUIC Kernel Module and Libquic will be built and installed simply by the commands below:
 
-    Packages Required: (kernel_version >= 5.14)
+    Packages Required: (kernel_version >= 6.1)
     - make autoconf automake libtool pkg-config
     - gnutls-devel kernel-devel (yum)
       gnutls-dev linux-headers-$(uname -r) (apt-get)

modules/net/quic/Kconfig

@@ -15,6 +15,7 @@ menuconfig IP_QUIC
 	select CRYPTO_CCM
 	select CRYPTO_CHACHA20POLY1305
 	select NET_UDP_TUNNEL
+	default n
 	help
 	  QUIC: A UDP-Based Multiplexed and Secure Transport
 

modules/net/quic/family.c

@@ -10,10 +10,8 @@
  *    Xin Long <lucien.xin@gmail.com>
  */
 
-#include <net/sock.h>
 #include <net/inet_common.h>
 #include <net/udp_tunnel.h>
-#include <linux/version.h>
 #include <linux/icmp.h>
 
 #include "common.h"
@@ -125,12 +123,8 @@ static int quic_v4_flow_route(struct sock *sk, union quic_addr *da, union quic_a
 	fl4->flowi4_proto = IPPROTO_UDP;
 	fl4->flowi4_oif = sk->sk_bound_dev_if;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 19, 0)
 	fl4->flowi4_scope = ip_sock_rt_scope(sk);
 	fl4->flowi4_tos = ip_sock_rt_tos(sk);
-#else
-	fl4->flowi4_tos = RT_CONN_FLAGS_TOS(sk, READ_ONCE(inet_sk(sk)->tos));
-#endif
 
 	rt = ip_route_output_key(sock_net(sk), fl4);
 	if (IS_ERR(rt))
@@ -166,7 +160,7 @@ static int quic_v6_flow_route(struct sock *sk, union quic_addr *da, union quic_a
 	fl6->flowi6_proto = IPPROTO_UDP;
 	fl6->flowi6_oif = sk->sk_bound_dev_if;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 7, 0)
+#ifdef inet6_test_bit
 	if (inet6_test_bit(SNDFLOW, sk)) {
 #else
 	if (np->sndflow) {

modules/net/quic/path.c

@@ -11,6 +11,7 @@
  */
 
 #include <net/udp_tunnel.h>
+#include <linux/version.h>
 #include <linux/quic.h>
 
 #include "common.h"
@@ -161,7 +162,11 @@ int quic_path_bind(struct sock *sk, struct quic_path_group *paths, u8 path)
 		return 0;
 	}
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
+	inet_sk_get_local_port_range(sk, &low, &high);
+#else
 	inet_get_local_port_range(net, &low, &high);
+#endif
 	remaining = (high - low) + 1;
 	rover = (int)(((u64)get_random_u32() * remaining) >> 32) + low;
 	do {

modules/net/quic/protocol.c

@@ -10,16 +10,18 @@
  *    Xin Long <lucien.xin@gmail.com>
  */
 
-#include <net/sock.h>
 #include <net/inet_common.h>
 #include <linux/version.h>
 #include <linux/proc_fs.h>
 #include <net/protocol.h>
 #include <net/tls.h>
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 9, 0)
+#include <net/rps.h>
+#endif
+
 #include "socket.h"
 
-static DEFINE_PER_CPU(int, quic_memory_per_cpu_fw_alloc);
 static unsigned int quic_net_id __read_mostly;
 
 struct quic_transport_param quic_default_param __read_mostly;
@@ -131,8 +133,7 @@ static __poll_t quic_inet_poll(struct file *file, struct socket *sock, poll_tabl
 
 	poll_wait(file, sk_sleep(sk), wait);
 
-	/* Comment it out for compiling on the old kernel version for now. */
-	/* sock_rps_record_flow(sk); */
+	sock_rps_record_flow(sk); /* Record the flow's CPU association for RFS. */
 
 	/* A listening socket becomes readable when the accept queue is not empty. */
 	if (quic_is_listen(sk))
@@ -201,8 +202,7 @@ static struct ctl_table quic_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 10, 0)
+#ifndef register_sysctl
 	{ /* sentinel */ }
 #endif
 };
@@ -433,29 +433,13 @@ static struct inet_protosw quicv6_dgram_protosw = {
 
 static int quic_protosw_init(void)
 {
-	struct proto *proto;
-	void *offset;
 	int err;
 
-	proto = &quic_prot;
-	offset = (void *)(&proto->memory_allocated) + sizeof(proto->memory_allocated);
-	if (offset != (void *)&proto->sockets_allocated) /* per_cpu_fw_alloc */
-		*(int  __percpu **)offset = &quic_memory_per_cpu_fw_alloc;
-
-	err = proto_register(proto, 1);
+	err = proto_register(&quic_prot, 1);
 	if (err)
 		return err;
 
-	proto = &quicv6_prot;
-	offset = (void *)(&proto->memory_allocated) + sizeof(proto->memory_allocated);
-	if (offset != (void *)&proto->sockets_allocated) /* per_cpu_fw_alloc */
-		*(int  __percpu **)offset = &quic_memory_per_cpu_fw_alloc;
-
-	offset = (void *)(&proto->obj_size) + sizeof(proto->obj_size);
-	if (offset != &proto->slab_flags) /* ipv6_pinfo_offset */
-		*(unsigned int *)offset = offsetof(struct quic6_sock, inet6);
-
-	err = proto_register(proto, 1);
+	err = proto_register(&quicv6_prot, 1);
 	if (err) {
 		proto_unregister(&quic_prot);
 		return err;

modules/net/quic/socket.c

@@ -10,14 +10,14 @@
  *    Xin Long <lucien.xin@gmail.com>
  */
 
-#include <net/sock.h>
 #include <net/inet_common.h>
 #include <linux/version.h>
 #include <asm/ioctls.h>
 #include <net/tls.h>
 
 #include "socket.h"
 
+static DEFINE_PER_CPU(int, quic_memory_per_cpu_fw_alloc);
 static unsigned long quic_memory_pressure;
 static atomic_long_t quic_memory_allocated;
 
@@ -288,8 +288,7 @@ static void quic_sock_fetch_transport_param(struct sock *sk, struct quic_transpo
 	quic_stream_get_param(quic_streams(sk), p, quic_is_serv(sk));
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 5, 0) || \
-	(defined(RHEL_RELEASE_CODE) && RHEL_RELEASE_CODE >= 2308) /* RHEL-9.4 */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 5, 0)
 static int quic_ioctl(struct sock *sk, int cmd, int *karg)
 {
 	int err = 0;
@@ -1058,10 +1057,10 @@ static int quic_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
 }
 
 /* Wait for an incoming QUIC packet. */
-static int quic_wait_for_packet(struct sock *sk, int nonblock)
+static int quic_wait_for_packet(struct sock *sk, u32 flags)
 {
+	long timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 	struct list_head *head = &quic_inq(sk)->recv_list;
-	long timeo = sock_rcvtimeo(sk, nonblock);
 	DEFINE_WAIT(wait);
 	int err = 0;
 
@@ -1096,16 +1095,9 @@ static int quic_wait_for_packet(struct sock *sk, int nonblock)
 	return err;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 19, 0)
 static int quic_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
 			int *addr_len)
 {
-	int nonblock = flags & MSG_DONTWAIT;
-#else
-static int quic_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
-			int flags, int *addr_len)
-{
-#endif
 	u32 copy, copied = 0, freed = 0, bytes = 0;
 	struct quic_handshake_info hinfo = {};
 	struct quic_stream_info sinfo = {};
@@ -1116,7 +1108,7 @@ static int quic_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int non
 
 	lock_sock(sk);
 
-	err = quic_wait_for_packet(sk, nonblock);
+	err = quic_wait_for_packet(sk, flags);
 	if (err)
 		goto out;
 
@@ -1418,8 +1410,7 @@ static int quic_accept_sock_setup(struct sock *sk, struct quic_request_sock *req
 	return err;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 10, 0) || \
-	(defined(RHEL_RELEASE_CODE) && RHEL_RELEASE_CODE >= 2310) /* RHEL-9.6 */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 10, 0)
 static struct sock *quic_accept(struct sock *sk, struct proto_accept_arg *arg)
 {
 	int flags = arg->flags, *errp = &arg->err;
@@ -2547,6 +2538,7 @@ struct proto quic_prot = {
 	.memory_pressure	=  &quic_memory_pressure,
 	.enter_memory_pressure	=  quic_enter_memory_pressure,
 	.memory_allocated	=  &quic_memory_allocated,
+	.per_cpu_fw_alloc	=  &quic_memory_per_cpu_fw_alloc,
 	.sockets_allocated	=  &quic_sockets_allocated,
 };
 
@@ -2572,11 +2564,15 @@ struct proto quicv6_prot = {
 	.release_cb	=  quic_release_cb,
 	.no_autobind	=  true,
 	.obj_size	= sizeof(struct quic6_sock),
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 6, 0)
+	.ipv6_pinfo_offset	=  offsetof(struct quic6_sock, inet6),
+#endif
 	.sysctl_mem		=  sysctl_quic_mem,
 	.sysctl_rmem		=  sysctl_quic_rmem,
 	.sysctl_wmem		=  sysctl_quic_wmem,
 	.memory_pressure	=  &quic_memory_pressure,
 	.enter_memory_pressure	=  quic_enter_memory_pressure,
 	.memory_allocated	=  &quic_memory_allocated,
+	.per_cpu_fw_alloc	=  &quic_memory_per_cpu_fw_alloc,
 	.sockets_allocated	=  &quic_sockets_allocated,
 };

modules/net/quic/test/unit_test.c

@@ -10,7 +10,6 @@
  *    Xin Long <lucien.xin@gmail.com>
  */
 
-#include <linux/version.h>
 #include <linux/skbuff.h>
 #include <linux/delay.h>
 #include <linux/quic.h>

modules/net/quic/timer.c

@@ -234,7 +234,11 @@ void quic_timer_stop(struct sock *sk, u8 type)
 			sock_put(sk);
 		return;
 	}
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 2, 0)
 	if (timer_delete(quic_timer(sk, type)))
+#else
+	if (del_timer(quic_timer(sk, type)))
+#endif
 		sock_put(sk);
 }