Make.Rules

# Common version number defines for libcap
LIBTITLE=libcap
VERSION=2
MINOR=72

#
## Optional prefixes:
#

# common 'packaging' directory

FAKEROOT=$(DESTDIR)

# Autoconf-style prefixes are activated when $(prefix) is defined.
# Otherwise binaries and libraries are installed in /{lib,sbin}/,
# header files in /usr/include/ and documentation in /usr/man/man?/.
# These choices are motivated by the fact that getcap and setcap are
# administrative operations that could be needed to recover a system.

ifndef lib
lib=$(shell ldd /usr/bin/ld|grep -E "ld-linux|ld.so"|cut -d/ -f2)
endif

ifndef sbin
sbin=sbin
endif

ifdef sbindir
sbin=$(sbindir)
endif

ifdef prefix
exec_prefix=$(prefix)
lib_prefix=$(exec_prefix)
inc_prefix=$(lib_prefix)
man_prefix=$(prefix)/share
else
prefix=/usr
exec_prefix=
lib_prefix=$(exec_prefix)
inc_prefix=$(prefix)
man_prefix=$(prefix)/share
endif

# Target directories

MANDIR=$(man_prefix)/man
SBINDIR=$(exec_prefix)/$(sbin)
INCDIR=$(inc_prefix)/include
LIBDIR=$(lib_prefix)/$(lib)
PKGCONFIGDIR=$(LIBDIR)/pkgconfig
GOPKGDIR=$(prefix)/share/gocode/src

# From here on out, the Go module packages should always remain
# backwardly compatible. I will only resort to using major version 2
# etc if Go's syntax dramatically changes in a backwards incompatible
# manner. (Let's hope not. If that happens, I'll also drop deprecated
# API functions.)
GOMAJOR=1

# Compilation specifics

KERNEL_HEADERS := $(topdir)/libcap/include/uapi
LIBCAP_INCLUDES = -I$(KERNEL_HEADERS) -I$(topdir)/libcap/include
DEFINES := -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
SYSTEM_HEADERS = /usr/include

SUDO := sudo
CC := $(CROSS_COMPILE)gcc
LD := $(CC) -Wl,-x -shared -Wl,-shared
AR := $(CROSS_COMPILE)ar
RANLIB := $(CROSS_COMPILE)ranlib
OBJCOPY := $(CROSS_COMPILE)objcopy

# Reference:
#   CPPFLAGS used for building .o files from .c & .h files
#   CFLAGS used when building libraries from .o, .c and .h files

DEBUG = # -g -DDEBUG
WARNINGS=-Wall -Wwrite-strings -Wpointer-arith -Wcast-qual -Wcast-align \
	-Wstrict-prototypes -Wmissing-prototypes -Wnested-externs       \
	-Winline -Wshadow -Wunreachable-code
COPTS ?= -O2
CFLAGS ?= $(COPTS) $(DEBUG)
CFLAGS += $(WARNINGS)
CPPFLAGS += -Dlinux $(DEFINES) $(LIBCAP_INCLUDES)
LDFLAGS ?= # -g

BUILD_CC ?= $(CC)
BUILD_LD ?= $(BUILD_CC) -Wl,-x -shared
BUILD_COPTS ?= $(COPTS)
BUILD_CFLAGS ?= $(BUILD_COPTS)
BUILD_CPPFLAGS += -Dlinux $(WARNINGS) $(DEBUG) $(DEFINES) $(LIBCAP_INCLUDES)
BUILD_LDFLAGS ?= $(LDFLAGS)
BUILD_SED ?= sed
BUILD_GREP ?= grep
BUILD_EGREP ?= $(BUILD_GREP) -E
BUILD_FGREP ?= $(BUILD_GREP) -F

# Plan to eventually redefine BUILD_GPERF to be the actual gperf tool
# alias as per above. Typical distributions are upto a year behind
# HEAD so we'll not do that before 2023-01-01.
ifdef BUILD_GPERF
$(error BUILD_GPERF is now reserved, please use USE_GPERF=yes or no instead)
endif

USE_GPERF ?= $(shell which gperf >/dev/null 2>/dev/null && echo yes)

LIBCAPLIB := -L$(topdir)/libcap -lcap
PSXLINKFLAGS := -lpthread
LIBPSXLIB := -L$(topdir)/libcap -Wl,--no-as-needed -Wl,--whole-archive -lpsx -Wl,--no-whole-archive -Wl,--as-needed $(PSXLINKFLAGS)

INCS=$(topdir)/libcap/include/sys/capability.h
INDENT := $(shell if [ -n "$$(which indent 2>/dev/null)" ]; then echo "| indent -kr" ; fi)

# SHARED tracks whether or not the SHARED libraries (libcap.so,
# libpsx.so and pam_cap.so) are built. (Some environments don't
# support shared libraries.)
SHARED ?= yes
# DYNAMIC controls how capsh etc are linked - to shared or static libraries
# Force enabled with "make DYNAMIC=yes ...".
DYNAMIC := $(shell if [ ! -d "$(topdir)/.git" ]; then echo $(SHARED); else echo no ; fi)

PAM_CAP ?= $(shell if [ -f /usr/include/security/pam_modules.h ]; then echo $(SHARED) ; else echo no ; fi)

# If your system does not support pthreads, override this as "no".
#
#    make PTHREADS=no ...
#
# This implies no Go support and no C/C++ libpsx build. Why might you
# need libpsx for non-Go use? Tl;dr for POSIX semantics security:
#
#    https://sites.google.com/site/fullycapable/who-ordered-libpsx
#
PTHREADS ?= yes

ifeq ($(PTHREADS),yes)
GO ?= go
GOLANG ?= $(shell if [ -n "$(shell $(GO) version 2>/dev/null)" ]; then echo yes ; else echo no ; fi)
ifeq ($(GOLANG),yes)
GOROOT ?= $(shell $(GO) env GOROOT)
GOCGO ?= $(shell if [ "$(shell $(GO) env CGO_ENABLED)" = 1 ]; then echo yes ; else echo no ; fi)
GOOSARCH ?= $(shell $(GO) env GOHOSTOS)_$(shell $(GO) env GOHOSTARCH)
CGO_REQUIRED := $(shell $(topdir)/go/cgo-required.sh $(GO))
CGO_CFLAGS := $(LIBCAP_INCLUDES)
CGO_LDFLAGS := -L$(topdir)/libcap
GO_BUILD_FLAGS :=
endif
endif

# If you want capsh to launch with something other than /bin/bash
# build like this:
#
#   make CAPSH_SHELL='-DSHELL=\"/bin/sh\"'
#
# or undefine the following:
#CAPSH_SHELL := '-DSHELL="/bin/sh"'

# When installing setcap, you can arrange for the installation process
# to set its inheritable bit to be able to place capabilities on files.
# It can be used in conjunction with pam_cap (associated with su and
# certain users say) to make it useful for specially blessed users.
#
#    make RAISE_SETFCAP=yes install
#
# This is now defaulted to no because some distributions started
# shipping with all users blessed with full inheritable sets which
# makes no sense whatsoever!
#
# Indeed, it looked alarmingly like these distributions were recreating
# the environment for what became known as the sendmail-capabilities
# bug from 2000:
#
#  https://sites.google.com/site/fullycapable/Home/thesendmailcapabilitiesissue
#
# they are also nullifying the difference between a p-bit and an i-bit.
#
# Folk really should read this document, which explains there is a really
# important difference being lost here:
#
#  https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/33528.pdf
#
# In the context of this tree, on such such systems, a yes setting will
# guarantee that every user, by default, is able to bless any binary with
# any capability - a ready made local exploit mechanism.
RAISE_SETFCAP := no

# If set to yes, this will cause the go "web" demo app to force the needed p
# bit to be able to bind to port 80 without running as root.
RAISE_GO_FILECAP := no

# Global cleanup stuff

LOCALCLEAN=rm -f *~ core
DISTCLEAN=@find . \( -name '*.orig' -o -name '*.rej' \) | xargs rm -f