bpftool: implement prog load command

Add the prog load command to load a bpf program from a specified
binary file and pin it to bpffs.

Usage description and examples are given in the corresponding man
page.

Syntax:
$ bpftool prog load OBJ FILE

FILE is a non-existing file on bpffs.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

5 files changed, 79 insertions, 34 deletions

diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 36e8d1c3c40d..ffdb20e8280f 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -15,7 +15,7 @@ SYNOPSIS
         *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } }
 
         *COMMANDS* :=
-        { **show** | **dump xlated** | **dump jited** | **pin** | **help** }
+        { **show** | **dump xlated** | **dump jited** | **pin** | **load** | **help** }
 
 MAP COMMANDS
 =============
@@ -24,6 +24,7 @@ MAP COMMANDS
 |       **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes**}]
 |       **bpftool** **prog dump jited**  *PROG* [{**file** *FILE* | **opcodes**}]
 |       **bpftool** **prog pin** *PROG* *FILE*
+|       **bpftool** **prog load** *OBJ* *FILE*
 |       **bpftool** **prog help**
 |
 |       *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
@@ -57,6 +58,11 @@ DESCRIPTION
 
                   Note: *FILE* must be located in *bpffs* mount.
 
+        **bpftool prog load** *OBJ* *FILE*
+                  Load bpf program from binary *OBJ* and pin as *FILE*.
+
+                  Note: *FILE* must be located in *bpffs* mount.
+
         **bpftool prog help**
                   Print short help message.
 
@@ -126,8 +132,10 @@ EXAMPLES
 |
 | **# mount -t bpf none /sys/fs/bpf/**
 | **# bpftool prog pin id 10 /sys/fs/bpf/prog**
+| **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2**
 | **# ls -l /sys/fs/bpf/**
 |   -rw------- 1 root root 0 Jul 22 01:43 prog
+|   -rw------- 1 root root 0 Jul 22 01:44 prog2
 
 **# bpftool prog dum jited pinned /sys/fs/bpf/prog opcodes**
 
diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst
index 926c03d5a8da..f547a0c0aa34 100644
--- a/tools/bpf/bpftool/Documentation/bpftool.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool.rst
@@ -26,7 +26,7 @@ SYNOPSIS
         | **pin** | **help** }
 
         *PROG-COMMANDS* := { **show** | **dump jited** | **dump xlated** | **pin**
-        | **help** }
+        | **load** | **help** }
 
 DESCRIPTION
 ===========
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 2bd3b280e6dd..b62c94e3997a 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -163,13 +163,49 @@ int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
         return fd;
 }
 
-int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
+int do_pin_fd(int fd, const char *name)
 {
         char err_str[ERR_MAX_LEN];
-        unsigned int id;
-        char *endptr;
         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));
+                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 {
+                err_str[ERR_MAX_LEN - 1] = '\0';
+                p_err("can't mount BPF file system to pin the object (%s): %s",
+                      name, err_str);
+        }
+
+out_free:
+        free(file);
+out:
+        return err;
+}
+
+int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
+{
+        unsigned int id;
+        char *endptr;
         int err;
         int fd;
 
@@ -195,35 +231,8 @@ int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
                 return -1;
         }
 
-        err = bpf_obj_pin(fd, *argv);
-        if (!err)
-                goto out_close;
-
-        file = malloc(strlen(*argv) + 1);
-        strcpy(file, *argv);
-        dir = dirname(file);
-
-        if (errno != EPERM || is_bpffs(dir)) {
-                p_err("can't pin the object (%s): %s", *argv, strerror(errno));
-                goto out_free;
-        }
+        err = do_pin_fd(fd, *argv);
 
-        /* Attempt to mount bpffs, then retry pinning. */
-        err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
-        if (!err) {
-                err = bpf_obj_pin(fd, *argv);
-                if (err)
-                        p_err("can't pin the object (%s): %s", *argv,
-                              strerror(errno));
-        } else {
-                err_str[ERR_MAX_LEN - 1] = '\0';
-                p_err("can't mount BPF file system to pin the object (%s): %s",
-                      *argv, err_str);
-        }
-
-out_free:
-        free(file);
-out_close:
         close(fd);
         return err;
 }
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index bff330b49791..bec1ccbb49c7 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -111,6 +111,7 @@ 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 do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32));
+int do_pin_fd(int fd, const char *name);
 
 int do_prog(int argc, char **arg);
 int do_map(int argc, char **arg);
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index ad619b96c276..037484ceaeaf 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -45,6 +45,7 @@
 #include <sys/stat.h>
 
 #include <bpf.h>
+#include <libbpf.h>
 
 #include "main.h"
 #include "disasm.h"
@@ -635,6 +636,30 @@ static int do_pin(int argc, char **argv)
         return err;
 }
 
+static int do_load(int argc, char **argv)
+{
+        struct bpf_object *obj;
+        int prog_fd;
+
+        if (argc != 2)
+                usage();
+
+        if (bpf_prog_load(argv[0], BPF_PROG_TYPE_UNSPEC, &obj, &prog_fd)) {
+                p_err("failed to load program\n");
+                return -1;
+        }
+
+        if (do_pin_fd(prog_fd, argv[1])) {
+                p_err("failed to pin program\n");
+                return -1;
+        }
+
+        if (json_output)
+                jsonw_null(json_wtr);
+
+        return 0;
+}
+
 static int do_help(int argc, char **argv)
 {
         if (json_output) {
@@ -647,13 +672,14 @@ static int do_help(int argc, char **argv)
                 "       %s %s dump xlated PROG [{ file FILE | opcodes }]\n"
                 "       %s %s dump jited  PROG [{ file FILE | opcodes }]\n"
                 "       %s %s pin   PROG FILE\n"
+                "       %s %s load  OBJ  FILE\n"
                 "       %s %s help\n"
                 "\n"
                 "       " HELP_SPEC_PROGRAM "\n"
                 "       " HELP_SPEC_OPTIONS "\n"
                 "",
                 bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
-                bin_name, argv[-2], bin_name, argv[-2]);
+                bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
 
         return 0;
 }
@@ -663,6 +689,7 @@ static const struct cmd cmds[] = {
         { "help",       do_help },
         { "dump",       do_dump },
         { "pin",        do_pin },
+        { "load",       do_load },
         { 0 }
 };