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 <opurdila@ixiacom.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 8b72c88..d0536b5 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -588,6 +588,37 @@
(i.e. by default) range 1024-4999 is enough to issue up to
2000 connections per second to systems supporting timestamps.
+ip_local_reserved_ports - list of comma separated ranges
+ Specify the ports which are reserved for known third-party
+ applications. These 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.
+
+ The format used for both input and output is a comma separated
+ list of ranges (e.g. "1,2-4,10-10" for ports 1, 2, 3, 4 and
+ 10). Writing to the file will clear all previously reserved
+ ports and update the current list with the one given in the
+ input.
+
+ Note that ip_local_port_range and ip_local_reserved_ports
+ settings are independent and both are considered by the kernel
+ when determining which ports are available for automatic port
+ assignments.
+
+ You can reserve ports which are not in the current
+ ip_local_port_range, e.g.:
+
+ $ cat /proc/sys/net/ipv4/ip_local_port_range
+ 32000 61000
+ $ cat /proc/sys/net/ipv4/ip_local_reserved_ports
+ 8080,9148
+
+ although this is redundant. However such a setting is useful
+ if later the port range is changed to a value that will
+ include the reserved ports.
+
+ Default: Empty
+
ip_nonlocal_bind - BOOLEAN
If set, allows processes to bind() to non-local IP addresses,
which can be quite useful - but may break some applications.