This commit adds support for loading/attaching/detaching flow
dissector program. The structure of the flow dissector program is
assumed to be the same as in the selftests:
* flow_dissector section with the main entry point
* a bunch of tail call progs
* a jmp_table map that is populated with the tail call progs
When `bpftool load` is called with a flow_dissector prog (i.e. when the
first section is flow_dissector of 'type flow_dissector' argument is
passed), we load and pin all the programs and build the jump table.
The last argument of `bpftool attach` is made optional for this use
case.
Example:
bpftool prog load tools/testing/selftests/bpf/bpf_flow.o \
/sys/fs/bpf/flow type flow_dissector
bpftool prog attach pinned /sys/fs/bpf/flow/flow_dissector/0 flow_dissector
Tested by using the above two lines to load the prog in
the test_flow_dissector.sh selftest.
Signed-off-by: Stanislav Fomichev <s...@google.com>
---
.../bpftool/Documentation/bpftool-prog.rst | 16 ++-
tools/bpf/bpftool/common.c | 32 +++--
tools/bpf/bpftool/main.h | 1 +
tools/bpf/bpftool/prog.c | 135 +++++++++++++++---
4 files changed, 141 insertions(+), 43 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index ac4e904b10fb..3caa9153435b 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -25,8 +25,8 @@ MAP COMMANDS
| **bpftool** **prog dump jited** *PROG* [{**file** *FILE* |
**opcodes**}]
| **bpftool** **prog pin** *PROG* *FILE*
| **bpftool** **prog load** *OBJ* *FILE* [**type** *TYPE*] [**map**
{**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*]
-| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* *MAP*
-| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* *MAP*
+| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
+| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
| **bpftool** **prog help**
|
| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
@@ -39,7 +39,9 @@ MAP COMMANDS
| **cgroup/bind4** | **cgroup/bind6** | **cgroup/post_bind4** |
**cgroup/post_bind6** |
| **cgroup/connect4** | **cgroup/connect6** | **cgroup/sendmsg4**
| **cgroup/sendmsg6**
| }
-| *ATTACH_TYPE* := { **msg_verdict** | **skb_verdict** | **skb_parse** }
+| *ATTACH_TYPE* := {
+| | **msg_verdict** | **skb_verdict** | **skb_parse** |
**flow_dissector**
+| }
DESCRIPTION
@@ -97,13 +99,13 @@ DESCRIPTION
contain a dot character ('.'), which is reserved for future
extensions of *bpffs*.
- **bpftool prog attach** *PROG* *ATTACH_TYPE* *MAP*
+ **bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
Attach bpf program *PROG* (with type specified by
*ATTACH_TYPE*)
- to the map *MAP*.
+ to the optional map *MAP*.
- **bpftool prog detach** *PROG* *ATTACH_TYPE* *MAP*
+ **bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
Detach bpf program *PROG* (with type specified by
*ATTACH_TYPE*)
- from the map *MAP*.
+ from the optional map *MAP*.
**bpftool prog help**
Print short help message.
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 25af85304ebe..963881142dfb 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -169,34 +169,24 @@ int open_obj_pinned_any(char *path, enum bpf_obj_type
exp_type)
return fd;
}
-int do_pin_fd(int fd, const char *name)
+int mount_bpffs_for_pin(const char *name)
{
char err_str[ERR_MAX_LEN];
char *file;
char *dir;
int err = 0;
- err = bpf_obj_pin(fd, name);
- if (!err)
- goto out;
-
file = malloc(strlen(name) + 1);
strcpy(file, name);
dir = dirname(file);
- if (errno != EPERM || is_bpffs(dir)) {
- p_err("can't pin the object (%s): %s", name, strerror(errno));
+ if (is_bpffs(dir)) {
+ /* nothing to do if already mounted */
goto out_free;
}
- /* Attempt to mount bpffs, then retry pinning. */
err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
- if (!err) {
- err = bpf_obj_pin(fd, name);
- if (err)
- p_err("can't pin the object (%s): %s", name,
- strerror(errno));
- } else {
+ if (err) {
err_str[ERR_MAX_LEN - 1] = '\0';
p_err("can't mount BPF file system to pin the object (%s): %s",
name, err_str);
@@ -204,10 +194,22 @@ int do_pin_fd(int fd, const char *name)
out_free:
free(file);
-out:
return err;
}
+int do_pin_fd(int fd, const char *name)
+{
+ int err = mount_bpffs_for_pin(name);
+
+ if (err) {
+ p_err("can't mount bpffs for pin %s: %s",
+ name, strerror(errno));
+ return err;
+ }
+
+ return bpf_obj_pin(fd, name);
+}
+
int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
{
unsigned int id;
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 28322ace2856..1383824c9baf 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -129,6 +129,7 @@ const char *get_fd_type_name(enum bpf_obj_type type);
char *get_fdinfo(int fd, const char *key);
int open_obj_pinned(char *path);
int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type);
+int mount_bpffs_for_pin(const char *name);
int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32));
int do_pin_fd(int fd, const char *name);
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 5302ee282409..f3a07ec3a444 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -81,6 +81,7 @@ static const char * const attach_type_strings[] = {
[BPF_SK_SKB_STREAM_PARSER] = "stream_parser",
[BPF_SK_SKB_STREAM_VERDICT] = "stream_verdict",
[BPF_SK_MSG_VERDICT] = "msg_verdict",
+ [BPF_FLOW_DISSECTOR] = "flow_dissector",
[__MAX_BPF_ATTACH_TYPE] = NULL,
};
@@ -724,9 +725,10 @@ int map_replace_compar(const void *p1, const void *p2)
static int do_attach(int argc, char **argv)
{
enum bpf_attach_type attach_type;
- int err, mapfd, progfd;
+ int err, progfd;
+ int mapfd = 0;
- if (!REQ_ARGS(5)) {
+ if (!REQ_ARGS(3)) {
p_err("too few parameters for map attach");
return -EINVAL;
}
@@ -741,10 +743,11 @@ static int do_attach(int argc, char **argv)
return -EINVAL;
}
NEXT_ARG();
-
- mapfd = map_parse_fd(&argc, &argv);
- if (mapfd < 0)
- return mapfd;
+ if (argc > 0) {
+ mapfd = map_parse_fd(&argc, &argv);
+ if (mapfd < 0)
+ return mapfd;
+ }
err = bpf_prog_attach(progfd, mapfd, attach_type, 0);
if (err) {
@@ -760,9 +763,10 @@ static int do_attach(int argc, char **argv)
static int do_detach(int argc, char **argv)
{
enum bpf_attach_type attach_type;
- int err, mapfd, progfd;
+ int err, progfd;
+ int mapfd = 0;
- if (!REQ_ARGS(5)) {
+ if (!REQ_ARGS(3)) {
p_err("too few parameters for map detach");
return -EINVAL;
}
@@ -777,10 +781,11 @@ static int do_detach(int argc, char **argv)
return -EINVAL;
}
NEXT_ARG();
-
- mapfd = map_parse_fd(&argc, &argv);
- if (mapfd < 0)
- return mapfd;
+ if (argc > 0) {
+ mapfd = map_parse_fd(&argc, &argv);
+ if (mapfd < 0)
+ return mapfd;
+ }
err = bpf_prog_detach2(progfd, mapfd, attach_type);
if (err) {
@@ -792,6 +797,56 @@ static int do_detach(int argc, char **argv)
jsonw_null(json_wtr);
return 0;
}
+
+/* Flow dissector consists of a main program and a jump table for each
+ * supported protocol. The assumption here is that the first prog is the main
+ * one and the other progs are used in the tail calls. In this routine we
+ * build the jump table for the non-main progs.
+ */
+static int build_flow_dissector_jmp_table(struct bpf_object *obj,
+ struct bpf_program *prog,
+ const char *jmp_table_map)
+{
+ struct bpf_map *jmp_table;
+ struct bpf_program *pos;
+ int i = 0;
+ int prog_fd, jmp_table_fd, fd;
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ p_err("failed to get fd of main prog");
+ return prog_fd;
+ }
+
+ jmp_table = bpf_object__find_map_by_name(obj, jmp_table_map);
+ if (jmp_table == NULL) {
+ p_err("failed to find '%s' map", jmp_table_map);
+ return -1;
+ }
+
+ jmp_table_fd = bpf_map__fd(jmp_table);
+ if (jmp_table_fd < 0) {
+ p_err("failed to get fd of jmp_table");
+ return jmp_table_fd;
+ }
+
+ bpf_object__for_each_program(pos, obj) {
+ fd = bpf_program__fd(pos);
+ if (fd < 0) {
+ p_err("failed to get fd of '%s'",
+ bpf_program__title(pos, false));
+ return fd;
+ }
+
+ if (fd != prog_fd) {
+ bpf_map_update_elem(jmp_table_fd, &i, &fd, BPF_ANY);
+ ++i;
+ }
+ }
+
+ return 0;
+}
+
static int do_load(int argc, char **argv)
{
enum bpf_attach_type expected_attach_type;
@@ -800,7 +855,7 @@ static int do_load(int argc, char **argv)
};
struct map_replace *map_replace = NULL;
unsigned int old_map_fds = 0;
- struct bpf_program *prog;
+ struct bpf_program *prog, *pos;
struct bpf_object *obj;
struct bpf_map *map;
const char *pinfile;
@@ -918,13 +973,19 @@ static int do_load(int argc, char **argv)
goto err_free_reuse_maps;
}
- prog = bpf_program__next(NULL, obj);
+ if (attr.prog_type == BPF_PROG_TYPE_FLOW_DISSECTOR) {
+ /* for the flow dissector type, the entry point is in the
+ * section flow_dissector; other progs are tail calls
+ */
+ prog = bpf_object__find_program_by_title(obj, "flow_dissector");
+ } else {
+ prog = bpf_program__next(NULL, obj);
+ }
if (!prog) {
p_err("object file doesn't contain any bpf program");
goto err_close_obj;
}
- bpf_program__set_ifindex(prog, ifindex);
if (attr.prog_type == BPF_PROG_TYPE_UNSPEC) {
const char *sec_name = bpf_program__title(prog, false);
@@ -936,8 +997,13 @@ static int do_load(int argc, char **argv)
goto err_close_obj;
}
}
- bpf_program__set_type(prog, attr.prog_type);
- bpf_program__set_expected_attach_type(prog, expected_attach_type);
+
+ bpf_object__for_each_program(pos, obj) {
+ bpf_program__set_ifindex(pos, ifindex);
+ bpf_program__set_type(pos, attr.prog_type);
+ bpf_program__set_expected_attach_type(pos,
+ expected_attach_type);
+ }
qsort(map_replace, old_map_fds, sizeof(*map_replace),
map_replace_compar);
@@ -1001,8 +1067,34 @@ static int do_load(int argc, char **argv)
goto err_close_obj;
}
- if (do_pin_fd(bpf_program__fd(prog), pinfile))
+ err = mount_bpffs_for_pin(pinfile);
+ if (err) {
+ p_err("failed to mount bpffs for pin '%s'", pinfile);
goto err_close_obj;
+ }
+
+ if (attr.prog_type == BPF_PROG_TYPE_FLOW_DISSECTOR) {
+ err = build_flow_dissector_jmp_table(obj, prog, "jmp_table");
+ if (err) {
+ p_err("failed to build flow dissector jump table");
+ goto err_close_obj;
+ }
+ /* flow dissector consist of multiple programs,
+ * we want to pin them all
+ */
+ err = bpf_object__pin(obj, pinfile);
+ if (err) {
+ p_err("failed to pin flow dissector object");
+ goto err_close_obj;
+ }
+ } else {
+ err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
+ if (err) {
+ p_err("failed to pin program %s",
+ bpf_program__title(prog, false));
+ goto err_close_obj;
+ }
+ }
if (json_output)
jsonw_null(json_wtr);
@@ -1037,8 +1129,8 @@ static int do_help(int argc, char **argv)
" %s %s pin PROG FILE\n"
" %s %s load OBJ FILE [type TYPE] [dev NAME] \\\n"
" [map { idx IDX | name NAME } MAP]\n"
- " %s %s attach PROG ATTACH_TYPE MAP\n"
- " %s %s detach PROG ATTACH_TYPE MAP\n"
+ " %s %s attach PROG ATTACH_TYPE [MAP]\n"
+ " %s %s detach PROG ATTACH_TYPE [MAP]\n"
" %s %s help\n"
"\n"
" " HELP_SPEC_MAP "\n"
@@ -1050,7 +1142,8 @@ static int do_help(int argc, char **argv)
" cgroup/bind4 | cgroup/bind6 |
cgroup/post_bind4 |\n"
" cgroup/post_bind6 | cgroup/connect4 |
cgroup/connect6 |\n"
" cgroup/sendmsg4 | cgroup/sendmsg6 }\n"
- " ATTACH_TYPE := { msg_verdict | skb_verdict | skb_parse
}\n"
+ " ATTACH_TYPE := { msg_verdict | skb_verdict | skb_parse
|\n"
+ " flow_dissector }\n"
" " HELP_SPEC_OPTIONS "\n"
"",
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
--
2.19.1.930.g4563a0d9d0-goog
