From: David Woodhouse <[email protected]> Wrap the IPv4-specific registrations in inet_init() with CONFIG_LEGACY_IP guards. When LEGACY_IP is disabled, the kernel will not: - Register the AF_INET socket family - Register the ETH_P_IP packet handler (ip_rcv) - Initialize ARP, ICMP, IGMP, or IPv4 routing - Register IPv4 protocol handlers (TCP/UDP/ICMP over IPv4) - Initialize IPv4 multicast routing, proc entries, or fragmentation
The shared INET infrastructure (tcp_prot, udp_prot, tcp_init, etc.) remains initialized for use by IPv6. Also update INDIRECT_CALL_INET to not use ip_rcv/ip_list_rcv as direct call targets when LEGACY_IP is disabled, avoiding a link-time reference to functions that will eventually be compiled out. Signed-off-by: David Woodhouse <[email protected]> --- include/linux/indirect_call_wrapper.h | 4 +++- net/ipv4/af_inet.c | 20 +++++++++++++----- net/ipv4/devinet.c | 2 ++ net/ipv4/route.c | 1 - net/ipv4/tcp_ipv4.c | 30 ++++++++++++++------------- 5 files changed, 36 insertions(+), 21 deletions(-) diff --git a/include/linux/indirect_call_wrapper.h b/include/linux/indirect_call_wrapper.h index dc272b514a01..25a3873da462 100644 --- a/include/linux/indirect_call_wrapper.h +++ b/include/linux/indirect_call_wrapper.h @@ -57,9 +57,11 @@ * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6 * alternatives */ -#if IS_BUILTIN(CONFIG_IPV6) +#if IS_BUILTIN(CONFIG_IPV6) && IS_ENABLED(CONFIG_LEGACY_IP) #define INDIRECT_CALL_INET(f, f2, f1, ...) \ INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__) +#elif IS_BUILTIN(CONFIG_IPV6) +#define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__) #elif IS_ENABLED(CONFIG_INET) #define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) #else diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c7731e300a44..dc358faa1647 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1922,7 +1922,15 @@ static int __init inet_init(void) /* * Tell SOCKET that we are alive... */ + /* Initialize the socket-side protocol switch tables. */ + for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) + INIT_LIST_HEAD(r); + +#ifdef CONFIG_XFRM + xfrm_init(); +#endif +#ifdef CONFIG_LEGACY_IP (void)sock_register(&inet_family_ops); #ifdef CONFIG_SYSCTL @@ -1957,10 +1965,6 @@ static int __init inet_init(void) pr_crit("%s: Cannot add IGMP protocol\n", __func__); #endif - /* Register the socket-side information for inet_create. */ - for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) - INIT_LIST_HEAD(r); - for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q) inet_register_protosw(q); @@ -1975,6 +1979,7 @@ static int __init inet_init(void) */ ip_init(); +#endif /* CONFIG_LEGACY_IP */ /* Initialise per-cpu ipv4 mibs */ if (init_ipv4_mibs()) @@ -1987,7 +1992,8 @@ static int __init inet_init(void) udp_init(); /* Add UDP-Lite (RFC 3828) */ - udplite4_register(); + if (IS_ENABLED(CONFIG_LEGACY_IP)) + udplite4_register(); raw_init(); @@ -1997,6 +2003,7 @@ static int __init inet_init(void) * Set the ICMP layer up */ +#ifdef CONFIG_LEGACY_IP if (icmp_init() < 0) panic("Failed to create the ICMP control socket.\n"); @@ -2007,10 +2014,12 @@ static int __init inet_init(void) if (ip_mr_init()) pr_crit("%s: Cannot init ipv4 mroute\n", __func__); #endif +#endif /* CONFIG_LEGACY_IP */ if (init_inet_pernet_ops()) pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__); +#ifdef CONFIG_LEGACY_IP ipv4_proc_init(); ipfrag_init(); @@ -2018,6 +2027,7 @@ static int __init inet_init(void) dev_add_pack(&ip_packet_type); ip_tunnel_core_init(); +#endif /* CONFIG_LEGACY_IP */ rc = 0; out: diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 537bb6c315d2..9b9db10e5db2 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -348,7 +348,9 @@ static int __init inet_blackhole_dev_init(void) return PTR_ERR_OR_ZERO(in_dev); } +#ifdef CONFIG_LEGACY_IP late_initcall(inet_blackhole_dev_init); +#endif int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b) { diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 463236e0dc2d..125614f552c7 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -3773,7 +3773,6 @@ int __init ip_rt_init(void) if (ip_rt_proc_init()) pr_err("Unable to create route proc files\n"); #ifdef CONFIG_XFRM - xfrm_init(); xfrm4_init(); #endif rtnl_register_many(ip_rt_rtnl_msg_handlers); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index c7b2463c2e25..7660bd45aac7 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3717,25 +3717,27 @@ static void __init bpf_iter_register(void) void __init tcp_v4_init(void) { - int cpu, res; + if (IS_ENABLED(CONFIG_LEGACY_IP)) { + int cpu, res; - for_each_possible_cpu(cpu) { - struct sock *sk; + for_each_possible_cpu(cpu) { + struct sock *sk; - res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, - IPPROTO_TCP, &init_net); - if (res) - panic("Failed to create the TCP control socket.\n"); - sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); + res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, + IPPROTO_TCP, &init_net); + if (res) + panic("Failed to create the TCP control socket.\n"); + sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); - /* Please enforce IP_DF and IPID==0 for RST and - * ACK sent in SYN-RECV and TIME-WAIT state. - */ - inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO; + /* Please enforce IP_DF and IPID==0 for RST and + * ACK sent in SYN-RECV and TIME-WAIT state. + */ + inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO; - sk->sk_clockid = CLOCK_MONOTONIC; + sk->sk_clockid = CLOCK_MONOTONIC; - per_cpu(ipv4_tcp_sk.sock, cpu) = sk; + per_cpu(ipv4_tcp_sk.sock, cpu) = sk; + } } if (register_pernet_subsys(&tcp_sk_ops)) panic("Failed to create the TCP control socket.\n"); -- 2.51.0
