Re: [PATCH] sysctl: Fix proc_do_large_bitmap for large input buffers

[Eric Sandeen]

Here's a pretty hacky test script to test this code via
ip_local_reserved_ports

-----

#!/bin/bash

# Randomly construct well-formed (sequential, non-overlapping)
# input for ip_local_reserved_ports, feed it to the sysctl,
# then read it back and check for differences.

# Port range to use
PORT_START=1024
PORT_STOP=32768

# Total length of ports string to use
LENGTH=$((4096+$((RANDOM % 16384))))

# String containing our list of ports
PORTS=$PORT_START

# Try 1000 times
for I in `seq 1 1000`; do
        
        # build up the string
        while true; do
                # Make sure it's discontiguous, skip ahead at least 2
                SKIP=$((2 + RANDOM % 10))
                PORT_START=$((PORT_START + SKIP))
        
                if [ "$PORT_START" -ge "$PORT_STOP" ]; then
                        break;
                fi
        
                # 14856-14863,14861
                # Add a range, or a single port
                USERANGE=$((RANDOM % 2))
        
                if [ "$USERANGE" -eq "1" ]; then
                        RANGE_START=$PORT_START
                        RANGE_LEN=$((1 + RANDOM % 10))
                        RANGE_END=$((RANGE_START + RANGE_LEN))
                        PORTS="${PORTS},${RANGE_START}-${RANGE_END}"
                        # Break out if we've done enough
                        if [ "$RANGE_END" -eq "$PORT_STOP" ]; then
                                break;
                        fi
                        PORT_START=$RANGE_END
                else
                        PORTS="${PORTS},${PORT_START}"
                fi
        
                if [ "${#PORTS}" -gt "$LENGTH" ]; then
                        break;
                fi
        
        done
        
        # See if we get out what we put in
        echo "Trial $I"
        echo $PORTS > port_list
        cat port_list > /proc/sys/net/ipv4/ip_local_reserved_ports || break
        cat /proc/sys/net/ipv4/ip_local_reserved_ports > port_list_out
        diff -uq port_list port_list_out || break
        
done