linux/samples/bpf/Makefile
Sargun Dhillon cf9b1199de samples/bpf: Add test/example of using bpf_probe_write_user bpf helper
This example shows using a kprobe to act as a dnat mechanism to divert
traffic for arbitrary endpoints. It rewrite the arguments to a syscall
while they're still in userspace, and before the syscall has a chance
to copy the argument into kernel space.

Although this is an example, it also acts as a test because the mapped
address is 255.255.255.255:555 -> real address, and that's not a legal
address to connect to. If the helper is broken, the example will fail
on the intermediate steps, as well as the final step to verify the
rewrite of userspace memory succeeded.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25 18:07:48 -07:00

142 lines
4.7 KiB
Makefile

# kbuild trick to avoid linker error. Can be omitted if a module is built.
obj- := dummy.o
# List of programs to build
hostprogs-y := test_verifier test_maps
hostprogs-y += sock_example
hostprogs-y += fds_example
hostprogs-y += sockex1
hostprogs-y += sockex2
hostprogs-y += sockex3
hostprogs-y += tracex1
hostprogs-y += tracex2
hostprogs-y += tracex3
hostprogs-y += tracex4
hostprogs-y += tracex5
hostprogs-y += tracex6
hostprogs-y += test_probe_write_user
hostprogs-y += trace_output
hostprogs-y += lathist
hostprogs-y += offwaketime
hostprogs-y += spintest
hostprogs-y += map_perf_test
hostprogs-y += test_overhead
hostprogs-y += test_cgrp2_array_pin
hostprogs-y += xdp1
hostprogs-y += xdp2
test_verifier-objs := test_verifier.o libbpf.o
test_maps-objs := test_maps.o libbpf.o
sock_example-objs := sock_example.o libbpf.o
fds_example-objs := bpf_load.o libbpf.o fds_example.o
sockex1-objs := bpf_load.o libbpf.o sockex1_user.o
sockex2-objs := bpf_load.o libbpf.o sockex2_user.o
sockex3-objs := bpf_load.o libbpf.o sockex3_user.o
tracex1-objs := bpf_load.o libbpf.o tracex1_user.o
tracex2-objs := bpf_load.o libbpf.o tracex2_user.o
tracex3-objs := bpf_load.o libbpf.o tracex3_user.o
tracex4-objs := bpf_load.o libbpf.o tracex4_user.o
tracex5-objs := bpf_load.o libbpf.o tracex5_user.o
tracex6-objs := bpf_load.o libbpf.o tracex6_user.o
test_probe_write_user-objs := bpf_load.o libbpf.o test_probe_write_user_user.o
trace_output-objs := bpf_load.o libbpf.o trace_output_user.o
lathist-objs := bpf_load.o libbpf.o lathist_user.o
offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o
spintest-objs := bpf_load.o libbpf.o spintest_user.o
map_perf_test-objs := bpf_load.o libbpf.o map_perf_test_user.o
test_overhead-objs := bpf_load.o libbpf.o test_overhead_user.o
test_cgrp2_array_pin-objs := libbpf.o test_cgrp2_array_pin.o
xdp1-objs := bpf_load.o libbpf.o xdp1_user.o
# reuse xdp1 source intentionally
xdp2-objs := bpf_load.o libbpf.o xdp1_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
always += sockex1_kern.o
always += sockex2_kern.o
always += sockex3_kern.o
always += tracex1_kern.o
always += tracex2_kern.o
always += tracex3_kern.o
always += tracex4_kern.o
always += tracex5_kern.o
always += tracex6_kern.o
always += test_probe_write_user_kern.o
always += trace_output_kern.o
always += tcbpf1_kern.o
always += lathist_kern.o
always += offwaketime_kern.o
always += spintest_kern.o
always += map_perf_test_kern.o
always += test_overhead_tp_kern.o
always += test_overhead_kprobe_kern.o
always += parse_varlen.o parse_simple.o parse_ldabs.o
always += test_cgrp2_tc_kern.o
always += xdp1_kern.o
always += xdp2_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable
HOSTLOADLIBES_fds_example += -lelf
HOSTLOADLIBES_sockex1 += -lelf
HOSTLOADLIBES_sockex2 += -lelf
HOSTLOADLIBES_sockex3 += -lelf
HOSTLOADLIBES_tracex1 += -lelf
HOSTLOADLIBES_tracex2 += -lelf
HOSTLOADLIBES_tracex3 += -lelf
HOSTLOADLIBES_tracex4 += -lelf -lrt
HOSTLOADLIBES_tracex5 += -lelf
HOSTLOADLIBES_tracex6 += -lelf
HOSTLOADLIBES_test_probe_write_user += -lelf
HOSTLOADLIBES_trace_output += -lelf -lrt
HOSTLOADLIBES_lathist += -lelf
HOSTLOADLIBES_offwaketime += -lelf
HOSTLOADLIBES_spintest += -lelf
HOSTLOADLIBES_map_perf_test += -lelf -lrt
HOSTLOADLIBES_test_overhead += -lelf -lrt
HOSTLOADLIBES_xdp1 += -lelf
HOSTLOADLIBES_xdp2 += -lelf
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
# make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
LLC ?= llc
CLANG ?= clang
# Trick to allow make to be run from this directory
all:
$(MAKE) -C ../../ $$PWD/
clean:
$(MAKE) -C ../../ M=$$PWD clean
@rm -f *~
# Verify LLVM compiler tools are available and bpf target is supported by llc
.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
verify_cmds: $(CLANG) $(LLC)
@for TOOL in $^ ; do \
if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
exit 1; \
else true; fi; \
done
verify_target_bpf: verify_cmds
@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
echo " NOTICE: LLVM version >= 3.7.1 required" ;\
exit 2; \
else true; fi
$(src)/*.c: verify_target_bpf
# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
# But, there is no easy way to fix it, so just exclude it since it is
# useless for BPF samples.
$(obj)/%.o: $(src)/%.c
$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
-Wno-compare-distinct-pointer-types \
-O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@