# SPDX-License-Identifier: GPL-2.0-or-later
#
# PASST - Plug A Simple Socket Transport
#  for qemu/UNIX domain socket mode
#
# PASTA - Pack A Subtle Tap Abstraction
#  for network namespace/tap device mode
#
# Copyright (c) 2021 Red Hat GmbH
# Author: Stefano Brivio <sbrivio@redhat.com>

VERSION ?= $(shell git describe --tags HEAD 2>/dev/null || echo "unknown\ version")

# Does the target platform allow IPv4 connections to be handled via
# the IPv6 socket API? (Linux does)
DUAL_STACK_SOCKETS := 1

RLIMIT_STACK_VAL := $(shell /bin/sh -c 'ulimit -s')
ifeq ($(RLIMIT_STACK_VAL),unlimited)
RLIMIT_STACK_VAL := 1024
endif

TARGET ?= $(shell $(CC) -dumpmachine)
# Get 'uname -m'-like architecture description for target
TARGET_ARCH := $(shell echo $(TARGET) | cut -f1 -d- | tr [A-Z] [a-z])
TARGET_ARCH := $(shell echo $(TARGET_ARCH) | sed 's/powerpc/ppc/')

AUDIT_ARCH := $(shell echo $(TARGET_ARCH) | tr [a-z] [A-Z] | sed 's/^ARM.*/ARM/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/I[456]86/I386/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/PPC64/PPC/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/PPCLE/PPC64LE/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/MIPS64EL/MIPSEL64/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/HPPA/PARISC/')
AUDIT_ARCH := $(shell echo $(AUDIT_ARCH) | sed 's/SH4/SH/')

# On some systems enabling optimization also enables source fortification,
# automagically. Do not override it.
FORTIFY_FLAG :=
ifeq ($(shell $(CC) -O2 -dM -E - < /dev/null 2>&1 | grep ' _FORTIFY_SOURCE ' > /dev/null; echo $$?),1)
FORTIFY_FLAG := -D_FORTIFY_SOURCE=2
endif

FLAGS := -Wall -Wextra -Wno-format-zero-length
FLAGS += -pedantic -std=c11 -D_XOPEN_SOURCE=700 -D_GNU_SOURCE
FLAGS +=  $(FORTIFY_FLAG) -O2 -pie -fPIE
FLAGS += -DPAGE_SIZE=$(shell getconf PAGE_SIZE)
FLAGS += -DNETNS_RUN_DIR=\"/run/netns\"
FLAGS += -DPASST_AUDIT_ARCH=AUDIT_ARCH_$(AUDIT_ARCH)
FLAGS += -DRLIMIT_STACK_VAL=$(RLIMIT_STACK_VAL)
FLAGS += -DARCH=\"$(TARGET_ARCH)\"
FLAGS += -DVERSION=\"$(VERSION)\"
FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS)

PASST_SRCS = arch.c arp.c checksum.c conf.c dhcp.c dhcpv6.c flow.c fwd.c \
	icmp.c igmp.c inany.c iov.c ip.c isolation.c lineread.c log.c mld.c \
	ndp.c netlink.c packet.c passt.c pasta.c pcap.c pif.c tap.c tcp.c \
	tcp_buf.c tcp_splice.c udp.c udp_flow.c util.c virtio.c
QRAP_SRCS = qrap.c
SRCS = $(PASST_SRCS) $(QRAP_SRCS)

MANPAGES = passt.1 pasta.1 qrap.1

PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h fwd.h \
	flow_table.h icmp.h icmp_flow.h inany.h iov.h ip.h isolation.h \
	lineread.h log.h ndp.h netlink.h packet.h passt.h pasta.h pcap.h pif.h \
	siphash.h tap.h tcp.h tcp_buf.h tcp_conn.h tcp_internal.h tcp_splice.h \
	udp.h udp_flow.h util.h virtio.h
HEADERS = $(PASST_HEADERS) seccomp.h

C := \#include <sys/random.h>\nint main(){int a=getrandom(0, 0, 0);}
ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0)
	FLAGS += -DHAS_GETRANDOM
endif

ifeq ($(shell :|$(CC) -fstack-protector-strong -S -xc - -o - >/dev/null 2>&1; echo $$?),0)
	FLAGS += -fstack-protector-strong
endif

C := \#define _GNU_SOURCE\n\#include <fcntl.h>\nint x = FALLOC_FL_COLLAPSE_RANGE;
ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0)
	EXTRA_SYSCALLS += fallocate
endif

prefix		?= /usr/local
exec_prefix	?= $(prefix)
bindir		?= $(exec_prefix)/bin
datarootdir	?= $(prefix)/share
docdir		?= $(datarootdir)/doc/passt
mandir		?= $(datarootdir)/man
man1dir		?= $(mandir)/man1

ifeq ($(TARGET_ARCH),x86_64)
BIN := passt passt.avx2 pasta pasta.avx2 qrap
else
BIN := passt pasta qrap
endif

all: $(BIN) $(MANPAGES) docs

static: FLAGS += -static -DGLIBC_NO_STATIC_NSS
static: clean all

seccomp.h: seccomp.sh $(PASST_SRCS) $(PASST_HEADERS)
	@ EXTRA_SYSCALLS="$(EXTRA_SYSCALLS)" ARCH="$(TARGET_ARCH)" CC="$(CC)" ./seccomp.sh $(PASST_SRCS) $(PASST_HEADERS)

passt: $(PASST_SRCS) $(HEADERS)
	$(CC) $(FLAGS) $(CFLAGS) $(CPPFLAGS) $(PASST_SRCS) -o passt $(LDFLAGS)

passt.avx2: FLAGS += -Ofast -mavx2 -ftree-vectorize -funroll-loops
passt.avx2: $(PASST_SRCS) $(HEADERS)
	$(CC) $(filter-out -O2,$(FLAGS)) $(CFLAGS) $(CPPFLAGS) \
		$(PASST_SRCS) -o passt.avx2 $(LDFLAGS)

passt.avx2: passt

pasta.avx2 pasta.1 pasta: pasta%: passt%
	ln -sf $< $@

qrap: $(QRAP_SRCS) passt.h
	$(CC) $(FLAGS) $(CFLAGS) $(CPPFLAGS) $(QRAP_SRCS) -o qrap $(LDFLAGS)

valgrind: EXTRA_SYSCALLS += rt_sigprocmask rt_sigtimedwait rt_sigaction	\
			    rt_sigreturn getpid gettid kill clock_gettime mmap \
			    mmap2 munmap open unlink gettimeofday futex
valgrind: FLAGS += -g -DVALGRIND
valgrind: all

.PHONY: clean
clean:
	$(RM) $(BIN) *~ *.o seccomp.h pasta.1 \
		passt.tar passt.tar.gz *.deb *.rpm \
		passt.pid README.plain.md

install: $(BIN) $(MANPAGES) docs
	mkdir -p $(DESTDIR)$(bindir) $(DESTDIR)$(man1dir)
	cp -d $(BIN) $(DESTDIR)$(bindir)
	cp -d $(MANPAGES) $(DESTDIR)$(man1dir)
	mkdir -p $(DESTDIR)$(docdir)
	cp -d README.plain.md $(DESTDIR)$(docdir)/README.md
	cp -d doc/demo.sh $(DESTDIR)$(docdir)

uninstall:
	$(RM) $(BIN:%=$(DESTDIR)$(prefix)/bin/%)
	$(RM) $(MANPAGES:%=$(DESTDIR)$(man1dir)/%)
	$(RM) $(DESTDIR)$(docdir)/README.md
	$(RM) $(DESTDIR)$(docdir)/demo.sh
	-rmdir $(DESTDIR)$(docdir)

pkgs: static
	tar cf passt.tar -P --xform 's//\/usr\/bin\//' $(BIN)
	tar rf passt.tar -P --xform 's//\/usr\/share\/man\/man1\//' \
		$(MANPAGES)
	gzip passt.tar
	EMAIL="sbrivio@redhat.com" fakeroot alien --to-deb \
		--description="User-mode networking for VMs and namespaces" \
		-k --version=$(shell git rev-parse --short HEAD) \
		passt.tar.gz
	fakeroot alien --to-rpm --target=$(shell uname -m) \
		--description="User-mode networking for VMs and namespaces" \
		-k --version=g$(shell git rev-parse --short HEAD) passt.tar.gz

# TODO: This hack makes a "plain" Markdown version of README.md that can be
# reasonably shipped as documentation file, while the current README.md is
# definitely intended for web browser consumption. It should probably work the
# other way around: the web version should be obtained by adding HTML and
# JavaScript portions to a plain Markdown, instead. However, cgit needs to use
# a file in the git tree. Find a better way around this.
docs: README.md
	@(								\
		skip=0;							\
		while read l; do					\
			case $$l in					\
			"## Demo")	exit 0		;;		\
			"<!"*)				;;		\
			"</"*)		skip=1		;;		\
			"<"*)		skip=2		;;		\
			esac;						\
									\
			[ $$skip -eq 0 ]	&& echo "$$l";		\
			[ $$skip -eq 1 ]	&& skip=0;		\
		done < README.md;					\
	) > README.plain.md

# Checkers currently disabled for clang-tidy:
# - llvmlibc-restrict-system-libc-headers
#	TODO: this is Linux-only for the moment, nice to fix eventually
#
# - google-readability-braces-around-statements
# - hicpp-braces-around-statements
# - readability-braces-around-statements
#	Debatable whether that improves readability, right now it would look
#	like a mess
#
# - readability-magic-numbers
# - cppcoreguidelines-avoid-magic-numbers
#	TODO: in most cases they are justified, but probably not everywhere
#
# - clang-analyzer-valist.Uninitialized
#	TODO: enable once https://bugs.llvm.org/show_bug.cgi?id=41311 is fixed
#
# - clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling
#	Probably not doable to impement this without plain memcpy(), memset()
#
# - cppcoreguidelines-init-variables
#	Dubious value, would kill readability
#
# - hicpp-signed-bitwise
#	Those are needed for syscalls, epoll_wait flags, etc.
#
# - llvm-include-order
#	TODO: not really important, but nice to fix eventually
#
# - readability-isolate-declaration
#	Dubious value, would kill readability
#
# - bugprone-narrowing-conversions
# - cppcoreguidelines-narrowing-conversions
#	TODO: nice to fix eventually
#
# - cppcoreguidelines-avoid-non-const-global-variables
#	TODO: check, fix, and more in general constify wherever possible
#
# - altera-unroll-loops
# - altera-id-dependent-backward-branch
#	TODO: check paths where it might make sense to improve performance
#
# - bugprone-easily-swappable-parameters
#	Not much can be done about them other than being careful
#
# - readability-function-cognitive-complexity
#	TODO: split reported functions
#
# - altera-struct-pack-align
#	"Poor" alignment needed for structs reflecting message formats/headers
#
# - concurrency-mt-unsafe
#	TODO: check again if multithreading is implemented
#
# - readability-identifier-length
#	Complains about any identifier <3 characters, reasonable for
#	globals, pointlessly verbose for locals and parameters.
#
# - bugprone-assignment-in-if-condition
#	Dubious value over the compiler's built-in warning.  Would
#	increase verbosity.
#
# - misc-include-cleaner
#	Wants to include headers which *directly* provide the things
#	we use.  That sounds nice, but means it will often want a OS
#	specific header instead of a mostly standard one, such as
#	<linux/limits.h> instead of <limits.h>.
#
# - cppcoreguidelines-macro-to-enum
#	Want to replace all #defines of integers with enums.  Kind of
#	makes sense when those defines form an enum-like set, but
#	weird for cases like standalone constants, and causes other
#	awkwardness for a bunch of cases we use
#
# - readability-math-missing-parentheses
#	It's been a couple of centuries since multiplication has been granted
#	precedence over addition in modern mathematical notation. Adding
#	parentheses to reinforce that certainly won't improve readability.


clang-tidy: $(filter-out qrap.c,$(SRCS)) $(HEADERS)
	clang-tidy -checks=*,-modernize-*,\
	-clang-analyzer-valist.Uninitialized,\
	-cppcoreguidelines-init-variables,\
	-bugprone-assignment-in-if-condition,\
	-google-readability-braces-around-statements,\
	-hicpp-braces-around-statements,\
	-readability-braces-around-statements,\
	-readability-magic-numbers,\
	-llvmlibc-restrict-system-libc-headers,\
	-hicpp-signed-bitwise,\
	-clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,\
	-llvm-include-order,\
	-cppcoreguidelines-avoid-magic-numbers,\
	-readability-isolate-declaration,\
	-bugprone-narrowing-conversions,\
	-cppcoreguidelines-narrowing-conversions,\
	-cppcoreguidelines-avoid-non-const-global-variables,\
	-altera-unroll-loops,-altera-id-dependent-backward-branch,\
	-bugprone-easily-swappable-parameters,\
	-readability-function-cognitive-complexity,\
	-altera-struct-pack-align,\
	-concurrency-mt-unsafe,\
	-readability-identifier-length,\
	-misc-include-cleaner,\
	-cppcoreguidelines-macro-to-enum,\
	-readability-math-missing-parentheses \
	-config='{CheckOptions: [{key: bugprone-suspicious-string-compare.WarnOnImplicitComparison, value: "false"}]}' \
	--warnings-as-errors=* $(filter-out qrap.c,$(SRCS)) -- $(filter-out -pie,$(FLAGS) $(CFLAGS) $(CPPFLAGS)) -DCLANG_TIDY_58992

SYSTEM_INCLUDES := /usr/include $(wildcard /usr/include/$(TARGET))
ifeq ($(shell $(CC) -v 2>&1 | grep -c "gcc version"),1)
VER := $(shell $(CC) -dumpversion)
SYSTEM_INCLUDES += /usr/lib/gcc/$(TARGET)/$(VER)/include
endif
cppcheck: $(SRCS) $(HEADERS)
	if cppcheck --check-level=exhaustive /dev/null > /dev/null 2>&1; then \
		CPPCHECK_EXHAUSTIVE="--check-level=exhaustive";		\
	else								\
		CPPCHECK_EXHAUSTIVE=;					\
	fi;								\
	cppcheck --std=c11 --error-exitcode=1 --enable=all --force	\
	--inconclusive --library=posix --quiet				\
	$${CPPCHECK_EXHAUSTIVE}						\
	$(SYSTEM_INCLUDES:%=-I%)					\
	$(SYSTEM_INCLUDES:%=--config-exclude=%)				\
	$(SYSTEM_INCLUDES:%=--suppress=*:%/*)				\
	$(SYSTEM_INCLUDES:%=--suppress=unmatchedSuppression:%/*)	\
	--inline-suppr							\
	--suppress=unusedStructMember					\
	$(filter -D%,$(FLAGS) $(CFLAGS) $(CPPFLAGS))			\
	$(SRCS) $(HEADERS)