Re: [PATCH bpf-next v1 05/13] tools/libbpf: Add support in libbpf for BPF_PROG_TYPE_LSM
From: Andrii Nakryiko <hidden>
Date: 2019-12-24 00:07:45
Also in:
bpf, lkml
On Fri, Dec 20, 2019 at 7:43 AM KP Singh [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: KP Singh <redacted> Update the libbpf library with functionality to load and attach a program type BPF_PROG_TYPE_LSM, currently with only one expected attach type BPF_LSM_MAC. Signed-off-by: KP Singh <redacted> --- tools/lib/bpf/bpf.c | 2 +- tools/lib/bpf/bpf.h | 6 +++++ tools/lib/bpf/libbpf.c | 44 +++++++++++++++++++++-------------- tools/lib/bpf/libbpf.h | 2 ++ tools/lib/bpf/libbpf.map | 6 +++++ tools/lib/bpf/libbpf_probes.c | 1 + 6 files changed, 43 insertions(+), 18 deletions(-)diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 98596e15390f..9c6fb083f7de 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c@@ -228,7 +228,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; attr.expected_attach_type = load_attr->expected_attach_type; - if (attr.prog_type == BPF_PROG_TYPE_TRACING) { + if (needs_btf_attach(attr.prog_type)) { attr.attach_btf_id = load_attr->attach_btf_id; attr.attach_prog_fd = load_attr->attach_prog_fd; } else {diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 3c791fa8e68e..df2a00ff349f 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h@@ -177,6 +177,12 @@ LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, __u64 *probe_addr); +static inline bool needs_btf_attach(enum bpf_prog_type prog_type) +{ + return (prog_type == BPF_PROG_TYPE_TRACING || + prog_type == BPF_PROG_TYPE_LSM); +} +
This doesn't have to be a public API, right? It also doesn't follow naming conventions of libbpf APIs. Let's just move it into libbpf_internal.h, given it's used in few files. Also, Martin's patches add STRUCT_OPS, which do need btf_attach, but don't set attach_prog_fd. So maybe something like libbpf_need_attach_prog_btf() for a name to be a bit more specific?
quoted hunk ↗ jump to hunk
#ifdef __cplusplus } /* extern "C" */ #endifdiff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b20f82e58989..b0b27d8e5a37 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c@@ -3738,7 +3738,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.insns = insns; load_attr.insns_cnt = insns_cnt; load_attr.license = license; - if (prog->type == BPF_PROG_TYPE_TRACING) { + if (needs_btf_attach(prog->type)) { load_attr.attach_prog_fd = prog->attach_prog_fd; load_attr.attach_btf_id = prog->attach_btf_id; } else {@@ -3983,7 +3983,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, bpf_program__set_type(prog, prog_type); bpf_program__set_expected_attach_type(prog, attach_type); - if (prog_type == BPF_PROG_TYPE_TRACING) { + if (needs_btf_attach(prog_type)) { err = libbpf_find_attach_btf_id(prog->section_name, attach_type, attach_prog_fd);@@ -4933,6 +4933,7 @@ bool bpf_program__is_##NAME(const struct bpf_program *prog) \ } \ BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); +BPF_PROG_TYPE_FNS(lsm, BPF_PROG_TYPE_LSM); BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS); BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT);@@ -5009,6 +5010,8 @@ static const struct { BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT), BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT), BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL), + BPF_PROG_BTF("lsm/", BPF_PROG_TYPE_LSM, + BPF_LSM_MAC),
Is is supposed to be attachable same as BPF_PROG_TYPE_TRACING
programs? If yes, please define auto-attaching function, similar to
SEC_DEF("raw_tp") few lines below this one.
quoted hunk ↗ jump to hunk
BPF_APROG_SEC("cgroup_skb/ingress", BPF_PROG_TYPE_CGROUP_SKB, BPF_CGROUP_INET_INGRESS), BPF_APROG_SEC("cgroup_skb/egress", BPF_PROG_TYPE_CGROUP_SKB,@@ -5119,32 +5122,39 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, return -ESRCH; } -#define BTF_PREFIX "btf_trace_" +static inline int __btf__typdef_with_prefix(struct btf *btf, const char *name,
typo: typdef -> typedef But actually let's generalize it to pass BTF_KIND as another param, I think I have a need for this (we might want to do that for structs, not just typedef->func_proto). Following btf__find_by_name_kind() naming, it probably should be called btf__find_by_prefix_kind()?
+ const char *prefix)
+{
+
+ size_t prefix_len = strlen(prefix);
+ char btf_type_name[128];
+
+ strcpy(btf_type_name, prefix);
+ strncat(btf_type_name, name, sizeof(btf_type_name) - (prefix_len + 1));at this point snprintf(btf_type_name, "%s%.*%s", prefix, sizeof(btf_type_name) - prefix_len - 1, name) looks like a better and cleaner alternative.
+ return btf__find_by_name_kind(btf, btf_type_name, BTF_KIND_TYPEDEF); +} + +#define BTF_TRACE_PREFIX "btf_trace_" +#define BTF_LSM_PREFIX "lsm_btf_" +
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