pktgen: new pktgen helper functions for samples scripts

Preparing for removing existing samples/pktgen/ scripts, and
replacing these with easier to use samples.

This commit provides two helper shell files, that can
be "included" by shell source'ing. Namely "functions.sh"
and "parameters.sh".

The parameters.sh file support easy and consistant parameter
parsing across the sample scripts.  Usage example is printed on
errors.

The functions.sh file provides, three new shell functions for
configuring the different components of pktgen: pg_ctrl(),
pg_thread() and pg_set().  A slightly improved version of the old
pgset() function is also provided for backwards compat.

The new functions correspond to pktgens different components.
 * pg_ctrl()   control "pgctrl" (/proc/net/pktgen/pgctrl)
 * pg_thread() control the kernel threads and binding to devices
 * pg_set()    control setup of individual devices

These changes are borrowed from:
 https://github.com/netoptimizer/network-testing/tree/master/pktgen

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 121 insertions, 0 deletions

diff --git a/samples/pktgen/functions.sh b/samples/pktgen/functions.sh
new file mode 100644
index 000000000000..205e4cde4601
--- /dev/null
+++ b/samples/pktgen/functions.sh
@@ -0,0 +1,121 @@
+#
+# Common functions used by pktgen scripts
+#  - Depending on bash 3 (or higher) syntax
+#
+# Author: Jesper Dangaaard Brouer
+# License: GPL
+
+## -- General shell logging cmds --
+function err() {
+    local exitcode=$1
+    shift
+    echo "ERROR: $@" >&2
+    exit $exitcode
+}
+
+function warn() {
+    echo "WARN : $@" >&2
+}
+
+function info() {
+    if [[ -n "$VERBOSE" ]]; then
+	echo "INFO : $@" >&2
+    fi
+}
+
+## -- Pktgen proc config commands -- ##
+export PROC_DIR=/proc/net/pktgen
+#
+# Three different shell functions for configuring the different
+# components of pktgen:
+#   pg_ctrl(), pg_thread() and pg_set().
+#
+# These functions correspond to pktgens different components.
+# * pg_ctrl()   control "pgctrl" (/proc/net/pktgen/pgctrl)
+# * pg_thread() control the kernel threads and binding to devices
+# * pg_set()    control setup of individual devices
+function pg_ctrl() {
+    local proc_file="pgctrl"
+    proc_cmd ${proc_file} "$@"
+}
+
+function pg_thread() {
+    local thread=$1
+    local proc_file="kpktgend_${thread}"
+    shift
+    proc_cmd ${proc_file} "$@"
+}
+
+function pg_set() {
+    local dev=$1
+    local proc_file="$dev"
+    shift
+    proc_cmd ${proc_file} "$@"
+}
+
+# More generic replacement for pgset(), that does not depend on global
+# variable for proc file.
+function proc_cmd() {
+    local result
+    local proc_file=$1
+    # after shift, the remaining args are contained in $@
+    shift
+    local proc_ctrl=${PROC_DIR}/$proc_file
+    if [[ ! -e "$proc_ctrl" ]]; then
+	err 3 "proc file:$proc_ctrl does not exists (dev added to thread?)"
+    else
+	if [[ ! -w "$proc_ctrl" ]]; then
+	    err 4 "proc file:$proc_ctrl not writable, not root?!"
+	fi
+    fi
+
+    if [[ "$DEBUG" == "yes" ]]; then
+	echo "cmd: $@ > $proc_ctrl"
+    fi
+    # Quoting of "$@" is important for space expansion
+    echo "$@" > "$proc_ctrl"
+    local status=$?
+
+    result=$(grep "Result: OK:" $proc_ctrl)
+    # Due to pgctrl, cannot use exit code $? from grep
+    if [[ "$result" == "" ]]; then
+	grep "Result:" $proc_ctrl >&2
+    fi
+    if (( $status != 0 )); then
+	err 5 "Write error($status) occurred cmd: \"$@ > $proc_ctrl\""
+    fi
+}
+
+# Old obsolete "pgset" function, with slightly improved err handling
+function pgset() {
+    local result
+
+    if [[ "$DEBUG" == "yes" ]]; then
+	echo "cmd: $1 > $PGDEV"
+    fi
+    echo $1 > $PGDEV
+    local status=$?
+
+    result=`cat $PGDEV | fgrep "Result: OK:"`
+    if [[ "$result" == "" ]]; then
+         cat $PGDEV | fgrep Result:
+    fi
+    if (( $status != 0 )); then
+	err 5 "Write error($status) occurred cmd: \"$1 > $PGDEV\""
+    fi
+}
+
+## -- General shell tricks --
+
+function root_check_run_with_sudo() {
+    # Trick so, program can be run as normal user, will just use "sudo"
+    #  call as root_check_run_as_sudo "$@"
+    if [ "$EUID" -ne 0 ]; then
+	if [ -x $0 ]; then # Directly executable use sudo
+	    info "Not root, running with sudo"
+            sudo "$0" "$@"
+            exit $?
+	fi
+	err 4 "cannot perform sudo run of $0"
+    fi
+}