From 2bae79d2d38f3dc50bfef81d3b4f7328b2883a17 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 12 Jul 2018 12:52:22 +0100 Subject: [PATCH 1/3] bpf: fix documentation for eBPF helpers Minor formatting edits for eBPF helpers documentation, including blank lines removal, fix of item list for return values in bpf_fib_lookup(), and missing prefix on bpf_skb_load_bytes_relative(). Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- include/uapi/linux/bpf.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b7db3261c62d1..6bcb287a888d4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1826,7 +1826,7 @@ union bpf_attr { * A non-negative value equal to or less than *size* on success, * or a negative error in case of failure. * - * int skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header) + * int bpf_skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header) * Description * This helper is similar to **bpf_skb_load_bytes**\ () in that * it provides an easy way to load *len* bytes from *offset* @@ -1877,7 +1877,7 @@ union bpf_attr { * * < 0 if any input argument is invalid * * 0 on success (packet is forwarded, nexthop neighbor exists) * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the - * * packet is not forwarded or needs assist from full stack + * packet is not forwarded or needs assist from full stack * * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags) * Description @@ -2033,7 +2033,6 @@ union bpf_attr { * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". - * * Return * 0 * @@ -2053,7 +2052,6 @@ union bpf_attr { * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". - * * Return * 0 * From 9b8ca3795199f333269859b0c8393f810b9616a3 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 12 Jul 2018 12:52:23 +0100 Subject: [PATCH 2/3] tools: bpf: synchronise BPF UAPI header with tools Update with latest changes from include/uapi/linux/bpf.h header. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 59b19b6a40d73..6bcb287a888d4 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1826,7 +1826,7 @@ union bpf_attr { * A non-negative value equal to or less than *size* on success, * or a negative error in case of failure. * - * int skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header) + * int bpf_skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header) * Description * This helper is similar to **bpf_skb_load_bytes**\ () in that * it provides an easy way to load *len* bytes from *offset* @@ -1857,7 +1857,8 @@ union bpf_attr { * is resolved), the nexthop address is returned in ipv4_dst * or ipv6_dst based on family, smac is set to mac address of * egress device, dmac is set to nexthop mac address, rt_metric - * is set to metric from route (IPv4/IPv6 only). + * is set to metric from route (IPv4/IPv6 only), and ifindex + * is set to the device index of the nexthop from the FIB lookup. * * *plen* argument is the size of the passed in struct. * *flags* argument can be a combination of one or more of the @@ -1873,9 +1874,10 @@ union bpf_attr { * *ctx* is either **struct xdp_md** for XDP programs or * **struct sk_buff** tc cls_act programs. * Return - * Egress device index on success, 0 if packet needs to continue - * up the stack for further processing or a negative error in case - * of failure. + * * < 0 if any input argument is invalid + * * 0 on success (packet is forwarded, nexthop neighbor exists) + * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the + * packet is not forwarded or needs assist from full stack * * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags) * Description @@ -2031,7 +2033,6 @@ union bpf_attr { * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". - * * Return * 0 * @@ -2051,7 +2052,6 @@ union bpf_attr { * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". - * * Return * 0 * @@ -2612,6 +2612,18 @@ struct bpf_raw_tracepoint_args { #define BPF_FIB_LOOKUP_DIRECT BIT(0) #define BPF_FIB_LOOKUP_OUTPUT BIT(1) +enum { + BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */ + BPF_FIB_LKUP_RET_BLACKHOLE, /* dest is blackholed; can be dropped */ + BPF_FIB_LKUP_RET_UNREACHABLE, /* dest is unreachable; can be dropped */ + BPF_FIB_LKUP_RET_PROHIBIT, /* dest not allowed; can be dropped */ + BPF_FIB_LKUP_RET_NOT_FWDED, /* packet is not forwarded */ + BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */ + BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */ + BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */ + BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */ +}; + struct bpf_fib_lookup { /* input: network family for lookup (AF_INET, AF_INET6) * output: network family of egress nexthop @@ -2625,7 +2637,11 @@ struct bpf_fib_lookup { /* total length of packet from network header - used for MTU check */ __u16 tot_len; - __u32 ifindex; /* L3 device index for lookup */ + + /* input: L3 device index for lookup + * output: device index from FIB lookup + */ + __u32 ifindex; union { /* inputs to lookup */ From 86f7d85cec9e1dba735ac5bd4b751b1908fedf80 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 12 Jul 2018 12:52:24 +0100 Subject: [PATCH 3/3] tools: bpf: build and install man page for eBPF helpers from bpftool/ Provide a new Makefile.helpers in tools/bpf, in order to build and install the man page for eBPF helpers. This Makefile is also included in the one used to build bpftool documentation, so that it can be called either on its own (cd tools/bpf && make -f Makefile.helpers) or from bpftool directory (cd tools/bpf/bpftool && make doc, or cd tools/bpf/bpftool/Documentation && make helpers). Makefile.helpers is not added directly to bpftool to avoid changing its Makefile too much (helpers are not 100% directly related with bpftool). But the possibility to build the page from bpftool directory makes us able to package the helpers man page with bpftool, and to install it along with bpftool documentation, so that the doc for helpers becomes easily available to developers through the "man" program. Cc: linux-man@vger.kernel.org Suggested-by: Daniel Borkmann Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/Makefile.helpers | 59 ++++++++++++++++++++++++ tools/bpf/bpftool/Documentation/Makefile | 13 ++++-- 2 files changed, 67 insertions(+), 5 deletions(-) create mode 100644 tools/bpf/Makefile.helpers diff --git a/tools/bpf/Makefile.helpers b/tools/bpf/Makefile.helpers new file mode 100644 index 0000000000000..c34fea77f39f6 --- /dev/null +++ b/tools/bpf/Makefile.helpers @@ -0,0 +1,59 @@ +ifndef allow-override + include ../scripts/Makefile.include + include ../scripts/utilities.mak +else + # Assume Makefile.helpers is being run from bpftool/Documentation + # subdirectory. Go up two more directories to fetch bpf.h header and + # associated script. + UP2DIR := ../../ +endif + +INSTALL ?= install +RM ?= rm -f +RMDIR ?= rmdir --ignore-fail-on-non-empty + +ifeq ($(V),1) + Q = +else + Q = @ +endif + +prefix ?= /usr/local +mandir ?= $(prefix)/man +man7dir = $(mandir)/man7 + +HELPERS_RST = bpf-helpers.rst +MAN7_RST = $(HELPERS_RST) + +_DOC_MAN7 = $(patsubst %.rst,%.7,$(MAN7_RST)) +DOC_MAN7 = $(addprefix $(OUTPUT),$(_DOC_MAN7)) + +helpers: man7 +man7: $(DOC_MAN7) + +RST2MAN_DEP := $(shell command -v rst2man 2>/dev/null) + +$(OUTPUT)$(HELPERS_RST): $(UP2DIR)../../include/uapi/linux/bpf.h + $(QUIET_GEN)$(UP2DIR)../../scripts/bpf_helpers_doc.py --filename $< > $@ + +$(OUTPUT)%.7: $(OUTPUT)%.rst +ifndef RST2MAN_DEP + $(error "rst2man not found, but required to generate man pages") +endif + $(QUIET_GEN)rst2man $< > $@ + +helpers-clean: + $(call QUIET_CLEAN, eBPF_helpers-manpage) + $(Q)$(RM) $(DOC_MAN7) $(OUTPUT)$(HELPERS_RST) + +helpers-install: helpers + $(call QUIET_INSTALL, eBPF_helpers-manpage) + $(Q)$(INSTALL) -d -m 755 $(DESTDIR)$(man7dir) + $(Q)$(INSTALL) -m 644 $(DOC_MAN7) $(DESTDIR)$(man7dir) + +helpers-uninstall: + $(call QUIET_UNINST, eBPF_helpers-manpage) + $(Q)$(RM) $(addprefix $(DESTDIR)$(man7dir)/,$(_DOC_MAN7)) + $(Q)$(RMDIR) $(DESTDIR)$(man7dir) + +.PHONY: helpers helpers-clean helpers-install helpers-uninstall diff --git a/tools/bpf/bpftool/Documentation/Makefile b/tools/bpf/bpftool/Documentation/Makefile index a9d47c1558bb1..f7663a3e60c91 100644 --- a/tools/bpf/bpftool/Documentation/Makefile +++ b/tools/bpf/bpftool/Documentation/Makefile @@ -15,12 +15,15 @@ prefix ?= /usr/local mandir ?= $(prefix)/man man8dir = $(mandir)/man8 -MAN8_RST = $(wildcard *.rst) +# Load targets for building eBPF helpers man page. +include ../../Makefile.helpers + +MAN8_RST = $(filter-out $(HELPERS_RST),$(wildcard *.rst)) _DOC_MAN8 = $(patsubst %.rst,%.8,$(MAN8_RST)) DOC_MAN8 = $(addprefix $(OUTPUT),$(_DOC_MAN8)) -man: man8 +man: man8 helpers man8: $(DOC_MAN8) RST2MAN_DEP := $(shell command -v rst2man 2>/dev/null) @@ -31,16 +34,16 @@ ifndef RST2MAN_DEP endif $(QUIET_GEN)rst2man $< > $@ -clean: +clean: helpers-clean $(call QUIET_CLEAN, Documentation) $(Q)$(RM) $(DOC_MAN8) -install: man +install: man helpers-install $(call QUIET_INSTALL, Documentation-man) $(Q)$(INSTALL) -d -m 755 $(DESTDIR)$(man8dir) $(Q)$(INSTALL) -m 644 $(DOC_MAN8) $(DESTDIR)$(man8dir) -uninstall: +uninstall: helpers-uninstall $(call QUIET_UNINST, Documentation-man) $(Q)$(RM) $(addprefix $(DESTDIR)$(man8dir)/,$(_DOC_MAN8)) $(Q)$(RMDIR) $(DESTDIR)$(man8dir)