From: Andrey Ignatov <r...@fb.com>
Support setting `expected_attach_type` at prog load time in both
`bpf/bpf.h` and `bpf/libbpf.h`.
Since both headers already have API to load programs, new functions are
added not to break backward compatibility for existing ones:
* `bpf_load_program_xattr()` is added to `bpf/bpf.h`;
* `bpf_prog_load_xattr()` is added to `bpf/libbpf.h`.
Both new functions accept structures, `struct bpf_load_program_attr` and
`struct bpf_prog_load_attr` correspondingly, where new fields can be
added in the future w/o changing the API.
Standard `_xattr` suffix is used to name the new API functions.
Since `bpf_load_program_name()` is not used as heavily as
`bpf_load_program()`, it was removed in favor of more generic
`bpf_load_program_xattr()`.
Signed-off-by: Andrey Ignatov <r...@fb.com>
Signed-off-by: Alexei Starovoitov <a...@kernel.org>
---
tools/include/uapi/linux/bpf.h | 5 ++
tools/lib/bpf/bpf.c | 44 +++++++++++------
tools/lib/bpf/bpf.h | 17 +++++--
tools/lib/bpf/libbpf.c | 105 +++++++++++++++++++++++++++++++----------
tools/lib/bpf/libbpf.h | 8 ++++
5 files changed, 133 insertions(+), 46 deletions(-)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index d245c41213ac..b44bcd7814ee 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -294,6 +294,11 @@ union bpf_attr {
__u32 prog_flags;
char prog_name[BPF_OBJ_NAME_LEN];
__u32 prog_ifindex; /* ifindex of netdev to prep
for */
+ /* For some prog types expected attach type must be known at
+ * load time to verify attach type specific parts of prog
+ * (context accesses, allowed helpers, etc).
+ */
+ __u32 expected_attach_type;
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 592a58a2b681..e85a2191f8b5 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -146,26 +146,30 @@ int bpf_create_map_in_map(enum bpf_map_type map_type,
const char *name,
-1);
}
-int bpf_load_program_name(enum bpf_prog_type type, const char *name,
- const struct bpf_insn *insns,
- size_t insns_cnt, const char *license,
- __u32 kern_version, char *log_buf,
- size_t log_buf_sz)
+int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
+ char *log_buf, size_t log_buf_sz)
{
- int fd;
union bpf_attr attr;
- __u32 name_len = name ? strlen(name) : 0;
+ __u32 name_len;
+ int fd;
+
+ if (!load_attr)
+ return -EINVAL;
+
+ name_len = load_attr->name ? strlen(load_attr->name) : 0;
bzero(&attr, sizeof(attr));
- attr.prog_type = type;
- attr.insn_cnt = (__u32)insns_cnt;
- attr.insns = ptr_to_u64(insns);
- attr.license = ptr_to_u64(license);
+ attr.prog_type = load_attr->prog_type;
+ attr.expected_attach_type = load_attr->expected_attach_type;
+ attr.insn_cnt = (__u32)load_attr->insns_cnt;
+ attr.insns = ptr_to_u64(load_attr->insns);
+ attr.license = ptr_to_u64(load_attr->license);
attr.log_buf = ptr_to_u64(NULL);
attr.log_size = 0;
attr.log_level = 0;
- attr.kern_version = kern_version;
- memcpy(attr.prog_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
+ attr.kern_version = load_attr->kern_version;
+ memcpy(attr.prog_name, load_attr->name,
+ min(name_len, BPF_OBJ_NAME_LEN - 1));
fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
if (fd >= 0 || !log_buf || !log_buf_sz)
@@ -184,8 +188,18 @@ int bpf_load_program(enum bpf_prog_type type, const struct
bpf_insn *insns,
__u32 kern_version, char *log_buf,
size_t log_buf_sz)
{
- return bpf_load_program_name(type, NULL, insns, insns_cnt, license,
- kern_version, log_buf, log_buf_sz);
+ struct bpf_load_program_attr load_attr;
+
+ memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
+ load_attr.prog_type = type;
+ load_attr.expected_attach_type = 0;
+ load_attr.name = NULL;
+ load_attr.insns = insns;
+ load_attr.insns_cnt = insns_cnt;
+ load_attr.license = license;
+ load_attr.kern_version = kern_version;
+
+ return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz);
}
int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 8d18fb73d7fb..2f7813d5e357 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -41,13 +41,20 @@ int bpf_create_map_in_map(enum bpf_map_type map_type, const
char *name,
int key_size, int inner_map_fd, int max_entries,
__u32 map_flags);
+struct bpf_load_program_attr {
+ enum bpf_prog_type prog_type;
+ enum bpf_attach_type expected_attach_type;
+ const char *name;
+ const struct bpf_insn *insns;
+ size_t insns_cnt;
+ const char *license;
+ __u32 kern_version;
+};
+
/* Recommend log buffer size */
#define BPF_LOG_BUF_SIZE (256 * 1024)
-int bpf_load_program_name(enum bpf_prog_type type, const char *name,
- const struct bpf_insn *insns,
- size_t insns_cnt, const char *license,
- __u32 kern_version, char *log_buf,
- size_t log_buf_sz);
+int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
+ char *log_buf, size_t log_buf_sz);
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 64a8fc384186..48e3e743ebf7 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -203,6 +203,8 @@ struct bpf_program {
struct bpf_object *obj;
void *priv;
bpf_program_clear_priv_t clear_priv;
+
+ enum bpf_attach_type expected_attach_type;
};
struct bpf_map {
@@ -1162,21 +1164,31 @@ static int bpf_object__collect_reloc(struct bpf_object
*obj)
}
static int
-load_program(enum bpf_prog_type type, const char *name, struct bpf_insn *insns,
- int insns_cnt, char *license, u32 kern_version, int *pfd)
+load_program(enum bpf_prog_type type, enum bpf_attach_type
expected_attach_type,
+ const char *name, struct bpf_insn *insns, int insns_cnt,
+ char *license, u32 kern_version, int *pfd)
{
- int ret;
+ struct bpf_load_program_attr load_attr;
char *log_buf;
+ int ret;
- if (!insns || !insns_cnt)
+ memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
+ load_attr.prog_type = type;
+ load_attr.expected_attach_type = expected_attach_type;
+ load_attr.name = name;
+ load_attr.insns = insns;
+ load_attr.insns_cnt = insns_cnt;
+ load_attr.license = license;
+ load_attr.kern_version = kern_version;
+
+ if (!load_attr.insns || !load_attr.insns_cnt)
return -EINVAL;
log_buf = malloc(BPF_LOG_BUF_SIZE);
if (!log_buf)
pr_warning("Alloc log buffer for bpf loader error, continue
without log\n");
- ret = bpf_load_program_name(type, name, insns, insns_cnt, license,
- kern_version, log_buf, BPF_LOG_BUF_SIZE);
+ ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE);
if (ret >= 0) {
*pfd = ret;
@@ -1192,18 +1204,18 @@ load_program(enum bpf_prog_type type, const char *name,
struct bpf_insn *insns,
pr_warning("-- BEGIN DUMP LOG ---\n");
pr_warning("\n%s\n", log_buf);
pr_warning("-- END LOG --\n");
- } else if (insns_cnt >= BPF_MAXINSNS) {
- pr_warning("Program too large (%d insns), at most %d insns\n",
- insns_cnt, BPF_MAXINSNS);
+ } else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
+ pr_warning("Program too large (%zu insns), at most %d insns\n",
+ load_attr.insns_cnt, BPF_MAXINSNS);
ret = -LIBBPF_ERRNO__PROG2BIG;
} else {
/* Wrong program type? */
- if (type != BPF_PROG_TYPE_KPROBE) {
+ if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
int fd;
- fd = bpf_load_program_name(BPF_PROG_TYPE_KPROBE, name,
- insns, insns_cnt, license,
- kern_version, NULL, 0);
+ load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
+ load_attr.expected_attach_type = 0;
+ fd = bpf_load_program_xattr(&load_attr, NULL, 0);
if (fd >= 0) {
close(fd);
ret = -LIBBPF_ERRNO__PROGTYPE;
@@ -1247,8 +1259,9 @@ bpf_program__load(struct bpf_program *prog,
pr_warning("Program '%s' is inconsistent: nr(%d) !=
1\n",
prog->section_name, prog->instances.nr);
}
- err = load_program(prog->type, prog->name, prog->insns,
- prog->insns_cnt, license, kern_version, &fd);
+ err = load_program(prog->type, prog->expected_attach_type,
+ prog->name, prog->insns, prog->insns_cnt,
+ license, kern_version, &fd);
if (!err)
prog->instances.fds[0] = fd;
goto out;
@@ -1276,8 +1289,8 @@ bpf_program__load(struct bpf_program *prog,
continue;
}
- err = load_program(prog->type, prog->name,
- result.new_insn_ptr,
+ err = load_program(prog->type, prog->expected_attach_type,
+ prog->name, result.new_insn_ptr,
result.new_insn_cnt,
license, kern_version, &fd);
@@ -1835,11 +1848,22 @@ BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT);
BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
-#define BPF_PROG_SEC(string, type) { string, sizeof(string) - 1, type }
+static void bpf_program__set_expected_attach_type(struct bpf_program *prog,
+ enum bpf_attach_type type)
+{
+ prog->expected_attach_type = type;
+}
+
+#define BPF_PROG_SEC_FULL(string, ptype, atype) \
+ { string, sizeof(string) - 1, ptype, atype }
+
+#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_FULL(string, ptype, 0)
+
static const struct {
const char *sec;
size_t len;
enum bpf_prog_type prog_type;
+ enum bpf_attach_type expected_attach_type;
} section_names[] = {
BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE),
@@ -1859,9 +1883,11 @@ static const struct {
BPF_PROG_SEC("sk_skb", BPF_PROG_TYPE_SK_SKB),
BPF_PROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG),
};
+
#undef BPF_PROG_SEC
+#undef BPF_PROG_SEC_FULL
-static enum bpf_prog_type bpf_program__guess_type(struct bpf_program *prog)
+static int bpf_program__identify_section(struct bpf_program *prog)
{
int i;
@@ -1871,13 +1897,13 @@ static enum bpf_prog_type
bpf_program__guess_type(struct bpf_program *prog)
for (i = 0; i < ARRAY_SIZE(section_names); i++)
if (strncmp(prog->section_name, section_names[i].sec,
section_names[i].len) == 0)
- return section_names[i].prog_type;
+ return i;
err:
pr_warning("failed to guess program type based on section name %s\n",
prog->section_name);
- return BPF_PROG_TYPE_UNSPEC;
+ return -1;
}
int bpf_map__fd(struct bpf_map *map)
@@ -1977,11 +2003,30 @@ long libbpf_get_error(const void *ptr)
int bpf_prog_load(const char *file, enum bpf_prog_type type,
struct bpf_object **pobj, int *prog_fd)
{
+ struct bpf_prog_load_attr attr;
+
+ memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
+ attr.file = file;
+ attr.prog_type = type;
+ attr.expected_attach_type = 0;
+
+ return bpf_prog_load_xattr(&attr, pobj, prog_fd);
+}
+
+int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
+ struct bpf_object **pobj, int *prog_fd)
+{
struct bpf_program *prog, *first_prog = NULL;
+ enum bpf_attach_type expected_attach_type;
+ enum bpf_prog_type prog_type;
struct bpf_object *obj;
+ int section_idx;
int err;
- obj = bpf_object__open(file);
+ if (!attr)
+ return -EINVAL;
+
+ obj = bpf_object__open(attr->file);
if (IS_ERR(obj))
return -ENOENT;
@@ -1990,15 +2035,23 @@ int bpf_prog_load(const char *file, enum bpf_prog_type
type,
* If type is not specified, try to guess it based on
* section name.
*/
- if (type == BPF_PROG_TYPE_UNSPEC) {
- type = bpf_program__guess_type(prog);
- if (type == BPF_PROG_TYPE_UNSPEC) {
+ prog_type = attr->prog_type;
+ expected_attach_type = attr->expected_attach_type;
+ if (prog_type == BPF_PROG_TYPE_UNSPEC) {
+ section_idx = bpf_program__identify_section(prog);
+ if (section_idx < 0) {
bpf_object__close(obj);
return -EINVAL;
}
+ prog_type = section_names[section_idx].prog_type;
+ expected_attach_type =
+ section_names[section_idx].expected_attach_type;
}
- bpf_program__set_type(prog, type);
+ bpf_program__set_type(prog, prog_type);
+ bpf_program__set_expected_attach_type(prog,
+ expected_attach_type);
+
if (prog->idx != obj->efile.text_shndx && !first_prog)
first_prog = prog;
}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f85906533cdd..a3a62a583f27 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -248,6 +248,14 @@ int bpf_map__pin(struct bpf_map *map, const char *path);
long libbpf_get_error(const void *ptr);
+struct bpf_prog_load_attr {
+ const char *file;
+ enum bpf_prog_type prog_type;
+ enum bpf_attach_type expected_attach_type;
+};
+
+int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
+ struct bpf_object **pobj, int *prog_fd);
int bpf_prog_load(const char *file, enum bpf_prog_type type,
struct bpf_object **pobj, int *prog_fd);
--
2.9.5
