Generate syscalls numbers with nr_syscalls.sh

Refactor filter.sh script by:
 * renaming the filter.sh to nr_syscalls.sh
 * removing the BPF filter generation
 * simplifying the syscall number and header generation

Signed-off-by: Alice Frosi <afrosi@redhat.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/nr_syscalls.sh b/nr_syscalls.sh
new file mode 100755
index 0000000..9ad3d19
--- /dev/null
+++ b/nr_syscalls.sh
@@ -0,0 +1,63 @@
+#!/bin/sh -eu
+#
+# SPDX-License-Identifier: AGPL-3.0-or-later
+#
+# SEITAN - Syscall Expressive Interpreter, Transformer and Notifier
+#
+# filter.sh - Build binary-search tree BPF program with SECCOMP_RET_USER_NOTIF
+#
+# Copyright (c) 2022 Red Hat GmbH
+# Author: Stefano Brivio <sbrivio@redhat.com>
+
+IN="${@}"
+OUT_NUMBERS="numbers.h"
+
+HEADER_NUMBERS="/* This file was automatically generated by $(basename ${0}) */
+#ifndef NUMBERS_H_
+#define NUMBERS_H_
+
+struct syscall_numbers {
+        char name[1024];
+        long number;
+};
+
+struct syscall_numbers numbers[] = {"
+
+FOOTER_NUMBERS="};
+
+#endif"
+
+syscalls=(
+	"accept"
+	"bind"
+	"connect"
+	"getpeername"
+	"getsockname"
+	"getsockopt"
+	"listen"
+	"mount"
+	"openat"
+	"recvfrom"
+	"recvmmsg"
+	"recvmsg"
+	"sendmmsg"
+	"sendmsg"
+	"sendto"
+	"setsockopt"
+	"shutdown"
+	"socket"
+	"socketpair"
+)
+
+printf '%s\n' "${HEADER_NUMBERS}" > "${OUT_NUMBERS}"
+# syscall_nr - Get syscall number from compiler, also note in numbers.h
+__in="$(printf "#include <asm-generic/unistd.h>\n#include <sys/syscall.h>\n__NR_%s" ${syscalls[@]})"
+__out="$(echo "${__in}" |cc -E -xc - -o - |sed -n '/\#.*$/!p'| sed '/^$/d')"
+
+awk  -v AS="${syscalls[*]}" -v BS="${__out[*]}" \
+'BEGIN { MAX=split(AS,a, / /); split(BS,b, / /);
+for (x = 1; x <= MAX; x++)
+         { printf "\t{\"%s\",\t%d},\n", a[x], b[x] }
+ }' >> "${OUT_NUMBERS}"
+
+printf '%s\n' "${FOOTER_NUMBERS}" >> "${OUT_NUMBERS}"