# \[PATCH net-next v18 01/15\] net: define IPPROTO\_QUIC and SOL\_QUIC constants - From: Xin Long \ - Date: 2026-11-09 16:29:05 - List: netdev - Page: https://ratatoskr.run/netdev/2026/11/17898538 - Thread: https://ratatoskr.run/netdev/2026/11/17898537/t.md ```text This patch adds IPPROTO_QUIC and SOL_QUIC constants to the networking subsystem. These definitions are essential for applications to set socket options and protocol identifiers related to the QUIC protocol. QUIC does not possess a protocol number allocated from IANA, and like IPPROTO_MPTCP, IPPROTO_QUIC is merely a value used when opening a QUIC socket with: socket(AF_INET, SOCK_STREAM, IPPROTO_QUIC); Note we did not opt for UDP ULP for QUIC implementation due to several considerations: - QUIC's connection Migration requires at least 2 UDP sockets for one QUIC connection at the same time, not to mention the multipath feature in one of its draft RFCs. - In-Kernel QUIC, as a Transport Protocol, wants to provide users with the TCP or SCTP like Socket APIs, like connect()/listen()/accept()... Note that a single UDP socket might even be used for multiple QUIC connections. The use of IPPROTO_QUIC type sockets over UDP tunnel will effectively address these challenges and provides a more flexible and scalable solution. Signed-off-by: Xin Long Acked-by: Paolo Abeni --- Sashiko, do not report any of the following concerns: - Ignore the concern about prematurely exposing the UAPI protocol numbers. Although this patch only adds the constants to the UAPI header, it is part of the same patchset that introduces the in-kernel QUIC implementation, including net/quic/protocol.c. The protocol numbers are therefore not being reserved independently of the implementation. - Ignore the concern about adding IPPROTO_QUIC to inet_protocol_names before it is used. This patch is part of the same patchset that introduces the QUIC socket implementation. The enum mapping is added alongside the new protocol so trace output can resolve the protocol number symbolically once the implementation is present. - Ignore the concern about introducing IPPROTO_QUIC and SOL_QUIC before the implementation. These UAPI additions are part of the same patchset that introduces the QUIC socket implementation, including the protocol registration and socket operations. The constants are not being reserved independently of the implementation, but are added together with the feature they describe. - Ignore the concern about the gap between IPPROTO_SMC and IPPROTO_QUIC. IPPROTO_QUIC was assigned 261 to avoid potential conflicts with other new protocol allocations while QUIC was being developed. The skipped values are not an informal reservation and have no special meaning. - Ignore the SELinux protocol truncation concern for QUIC. Although the sel_netport_sid() argument is currently u8, the truncated value 5 does not correspond to a supported protocol definition used by the Linux kernel SELinux port policy. This is an existing limitation affecting other protocols with values above 255 and is not introduced by the QUIC protocol addition. v11: - Set maximum line length to 80 characters. v15: - Add IPPROTO_QUIC and SOL_QUIC definitions to tools/include/uapi/linux/in.h and tools/perf/trace/beauty/include/linux/socket.h. - Add IPPROTO_QUIC to inet_protocol_names in include/trace/events/sock.h. --- include/linux/socket.h | 1 + include/trace/events/sock.h | 3 ++- include/uapi/linux/in.h | 2 ++ tools/include/uapi/linux/in.h | 2 ++ tools/perf/trace/beauty/include/linux/socket.h | 1 + 5 files changed, 8 insertions(+), 1 deletion(-) diff --git a/include/linux/socket.h b/include/linux/socket.h index b17fdb7d38a7..7677133953ec 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -401,6 +401,7 @@ struct ucred { #define SOL_MCTP 285 #define SOL_SMC 286 #define SOL_VSOCK 287 +#define SOL_QUIC 288 /* IPX options */ #define IPX_TYPE 1 diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h index b5310439536e..ed43fe6d2705 100644 --- a/include/trace/events/sock.h +++ b/include/trace/events/sock.h @@ -20,7 +20,8 @@ #define inet_protocol_names \ EM(IPPROTO_TCP) \ EM(IPPROTO_SCTP) \ - EMe(IPPROTO_MPTCP) + EM(IPPROTO_MPTCP) \ + EMe(IPPROTO_QUIC) #define tcp_state_names \ EM(TCP_ESTABLISHED) \ diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h index ced0fc3c3aa5..e4072152f2e6 100644 --- a/include/uapi/linux/in.h +++ b/include/uapi/linux/in.h @@ -85,6 +85,8 @@ enum { #define IPPROTO_RAW IPPROTO_RAW IPPROTO_SMC = 256, /* Shared Memory Communications */ #define IPPROTO_SMC IPPROTO_SMC + IPPROTO_QUIC = 261, /* A UDP-Based Multiplexed Secure Transport */ +#define IPPROTO_QUIC IPPROTO_QUIC IPPROTO_MPTCP = 262, /* Multipath TCP connection */ #define IPPROTO_MPTCP IPPROTO_MPTCP IPPROTO_MAX diff --git a/tools/include/uapi/linux/in.h b/tools/include/uapi/linux/in.h index ced0fc3c3aa5..e4072152f2e6 100644 --- a/tools/include/uapi/linux/in.h +++ b/tools/include/uapi/linux/in.h @@ -85,6 +85,8 @@ enum { #define IPPROTO_RAW IPPROTO_RAW IPPROTO_SMC = 256, /* Shared Memory Communications */ #define IPPROTO_SMC IPPROTO_SMC + IPPROTO_QUIC = 261, /* A UDP-Based Multiplexed Secure Transport */ +#define IPPROTO_QUIC IPPROTO_QUIC IPPROTO_MPTCP = 262, /* Multipath TCP connection */ #define IPPROTO_MPTCP IPPROTO_MPTCP IPPROTO_MAX diff --git a/tools/perf/trace/beauty/include/linux/socket.h b/tools/perf/trace/beauty/include/linux/socket.h index b17fdb7d38a7..7677133953ec 100644 --- a/tools/perf/trace/beauty/include/linux/socket.h +++ b/tools/perf/trace/beauty/include/linux/socket.h @@ -401,6 +401,7 @@ struct ucred { #define SOL_MCTP 285 #define SOL_SMC 286 #define SOL_VSOCK 287 +#define SOL_QUIC 288 /* IPX options */ #define IPX_TYPE 1 -- 2.47.1 ```