From e3826f1e946e7d2354943232f1457be1455a29e2 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Wed, 5 May 2010 00:27:06 +0000 Subject: net: reserve ports for applications using fixed port numbers (Dropped the infiniband part, because Tetsuo modified the related code, I will send a separate patch for it once this is accepted.) This patch introduces /proc/sys/net/ipv4/ip_local_reserved_ports which allows users to reserve ports for third-party applications. The reserved ports will not be used by automatic port assignments (e.g. when calling connect() or bind() with port number 0). Explicit port allocation behavior is unchanged. Signed-off-by: Octavian Purdila Signed-off-by: WANG Cong Cc: Neil Horman Cc: Eric Dumazet Cc: Eric W. Biederman Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 8 +++++++- net/ipv4/inet_connection_sock.c | 6 ++++++ net/ipv4/inet_hashtables.c | 2 ++ net/ipv4/sysctl_net_ipv4.c | 17 +++++++++++++++++ net/ipv4/udp.c | 3 ++- 5 files changed, 34 insertions(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c6c43bcd1c6f..551ce564b035 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1573,9 +1573,13 @@ static int __init inet_init(void) BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb)); + sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL); + if (!sysctl_local_reserved_ports) + goto out; + rc = proto_register(&tcp_prot, 1); if (rc) - goto out; + goto out_free_reserved_ports; rc = proto_register(&udp_prot, 1); if (rc) @@ -1674,6 +1678,8 @@ out_unregister_udp_proto: proto_unregister(&udp_prot); out_unregister_tcp_proto: proto_unregister(&tcp_prot); +out_free_reserved_ports: + kfree(sysctl_local_reserved_ports); goto out; } diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index e0a3e3537b14..70eb3507c406 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -37,6 +37,9 @@ struct local_ports sysctl_local_ports __read_mostly = { .range = { 32768, 61000 }, }; +unsigned long *sysctl_local_reserved_ports; +EXPORT_SYMBOL(sysctl_local_reserved_ports); + void inet_get_local_port_range(int *low, int *high) { unsigned seq; @@ -108,6 +111,8 @@ again: smallest_size = -1; do { + if (inet_is_reserved_local_port(rover)) + goto next_nolock; head = &hashinfo->bhash[inet_bhashfn(net, rover, hashinfo->bhash_size)]; spin_lock(&head->lock); @@ -130,6 +135,7 @@ again: break; next: spin_unlock(&head->lock); + next_nolock: if (++rover > high) rover = low; } while (--remaining > 0); diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 2b79377b468d..d3e160a88219 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -456,6 +456,8 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, local_bh_disable(); for (i = 1; i <= remaining; i++) { port = low + (i + offset) % remaining; + if (inet_is_reserved_local_port(port)) + continue; head = &hinfo->bhash[inet_bhashfn(net, port, hinfo->bhash_size)]; spin_lock(&head->lock); diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 1cd5c15174b8..d96c1da4b17c 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -299,6 +299,13 @@ static struct ctl_table ipv4_table[] = { .mode = 0644, .proc_handler = ipv4_local_port_range, }, + { + .procname = "ip_local_reserved_ports", + .data = NULL, /* initialized in sysctl_ipv4_init */ + .maxlen = 65536, + .mode = 0644, + .proc_handler = proc_do_large_bitmap, + }, #ifdef CONFIG_IP_MULTICAST { .procname = "igmp_max_memberships", @@ -736,6 +743,16 @@ static __net_initdata struct pernet_operations ipv4_sysctl_ops = { static __init int sysctl_ipv4_init(void) { struct ctl_table_header *hdr; + struct ctl_table *i; + + for (i = ipv4_table; i->procname; i++) { + if (strcmp(i->procname, "ip_local_reserved_ports") == 0) { + i->data = sysctl_local_reserved_ports; + break; + } + } + if (!i->procname) + return -EINVAL; hdr = register_sysctl_paths(net_ipv4_ctl_path, ipv4_table); if (hdr == NULL) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index f3e00c5cd1ed..9de6a698f91d 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -233,7 +233,8 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum, */ do { if (low <= snum && snum <= high && - !test_bit(snum >> udptable->log, bitmap)) + !test_bit(snum >> udptable->log, bitmap) && + !inet_is_reserved_local_port(snum)) goto found; snum += rand; } while (snum != first); -- cgit v1.2.3