Skip to content

Commit

Permalink
bpftool: Move out sections to separate functions
Browse files Browse the repository at this point in the history 
Remove all calls of print_end_then_start_section function and for loops
out from the do_probe function. Instead, provide separate functions for
each section (like i.e. section_helpers) which are called in do_probe.
This change is motivated by better readability.

Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200226165941.6379-2-mrostecki@opensuse.org
  • Loading branch information
Michal Rostecki authored and Daniel Borkmann committed Feb 26, 2020
1 parent 3494bec commit 6b52ca4
Showing 1 changed file with 126 additions and 93 deletions.
219 changes: 126 additions & 93 deletions tools/bpf/bpftool/feature.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -112,18 +112,12 @@ print_start_section(const char *json_title, const char *plain_title,
}
}

static void
print_end_then_start_section(const char *json_title, const char *plain_title,
const char *define_comment,
const char *define_prefix)
static void print_end_section(void)
{
if (json_output)
jsonw_end_object(json_wtr);
else
printf("\n");

print_start_section(json_title, plain_title, define_comment,
define_prefix);
}

/* Probing functions */
Expand Down Expand Up @@ -584,13 +578,130 @@ probe_large_insn_limit(const char *define_prefix, __u32 ifindex)
res, define_prefix);
}

static void
section_system_config(enum probe_component target, const char *define_prefix)
{
switch (target) {
case COMPONENT_KERNEL:
case COMPONENT_UNSPEC:
if (define_prefix)
break;

print_start_section("system_config",
"Scanning system configuration...",
NULL, /* define_comment never used here */
NULL); /* define_prefix always NULL here */
if (check_procfs()) {
probe_unprivileged_disabled();
probe_jit_enable();
probe_jit_harden();
probe_jit_kallsyms();
probe_jit_limit();
} else {
p_info("/* procfs not mounted, skipping related probes */");
}
probe_kernel_image_config();
print_end_section();
break;
default:
break;
}
}

static bool section_syscall_config(const char *define_prefix)
{
bool res;

print_start_section("syscall_config",
"Scanning system call availability...",
"/*** System call availability ***/",
define_prefix);
res = probe_bpf_syscall(define_prefix);
print_end_section();

return res;
}

static void
section_program_types(bool *supported_types, const char *define_prefix,
__u32 ifindex)
{
unsigned int i;

print_start_section("program_types",
"Scanning eBPF program types...",
"/*** eBPF program types ***/",
define_prefix);

for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++)
probe_prog_type(i, supported_types, define_prefix, ifindex);

print_end_section();
}

static void section_map_types(const char *define_prefix, __u32 ifindex)
{
unsigned int i;

print_start_section("map_types",
"Scanning eBPF map types...",
"/*** eBPF map types ***/",
define_prefix);

for (i = BPF_MAP_TYPE_UNSPEC + 1; i < map_type_name_size; i++)
probe_map_type(i, define_prefix, ifindex);

print_end_section();
}

static void
section_helpers(bool *supported_types, const char *define_prefix, __u32 ifindex)
{
unsigned int i;

print_start_section("helpers",
"Scanning eBPF helper functions...",
"/*** eBPF helper functions ***/",
define_prefix);

if (define_prefix)
printf("/*\n"
" * Use %sHAVE_PROG_TYPE_HELPER(prog_type_name, helper_name)\n"
" * to determine if <helper_name> is available for <prog_type_name>,\n"
" * e.g.\n"
" * #if %sHAVE_PROG_TYPE_HELPER(xdp, bpf_redirect)\n"
" * // do stuff with this helper\n"
" * #elif\n"
" * // use a workaround\n"
" * #endif\n"
" */\n"
"#define %sHAVE_PROG_TYPE_HELPER(prog_type, helper) \\\n"
" %sBPF__PROG_TYPE_ ## prog_type ## __HELPER_ ## helper\n",
define_prefix, define_prefix, define_prefix,
define_prefix);
for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++)
probe_helpers_for_progtype(i, supported_types[i],
define_prefix, ifindex);

print_end_section();
}

static void section_misc(const char *define_prefix, __u32 ifindex)
{
print_start_section("misc",
"Scanning miscellaneous eBPF features...",
"/*** eBPF misc features ***/",
define_prefix);
probe_large_insn_limit(define_prefix, ifindex);
print_end_section();
}

static int do_probe(int argc, char **argv)
{
enum probe_component target = COMPONENT_UNSPEC;
const char *define_prefix = NULL;
bool supported_types[128] = {};
__u32 ifindex = 0;
unsigned int i;
char *ifname;

/* Detection assumes user has sufficient privileges (CAP_SYS_ADMIN).
Expand Down Expand Up @@ -658,97 +769,19 @@ static int do_probe(int argc, char **argv)
jsonw_start_object(json_wtr);
}

switch (target) {
case COMPONENT_KERNEL:
case COMPONENT_UNSPEC:
if (define_prefix)
break;

print_start_section("system_config",
"Scanning system configuration...",
NULL, /* define_comment never used here */
NULL); /* define_prefix always NULL here */
if (check_procfs()) {
probe_unprivileged_disabled();
probe_jit_enable();
probe_jit_harden();
probe_jit_kallsyms();
probe_jit_limit();
} else {
p_info("/* procfs not mounted, skipping related probes */");
}
probe_kernel_image_config();
if (json_output)
jsonw_end_object(json_wtr);
else
printf("\n");
break;
default:
break;
}

print_start_section("syscall_config",
"Scanning system call availability...",
"/*** System call availability ***/",
define_prefix);

if (!probe_bpf_syscall(define_prefix))
section_system_config(target, define_prefix);
if (!section_syscall_config(define_prefix))
/* bpf() syscall unavailable, don't probe other BPF features */
goto exit_close_json;

print_end_then_start_section("program_types",
"Scanning eBPF program types...",
"/*** eBPF program types ***/",
define_prefix);

for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++)
probe_prog_type(i, supported_types, define_prefix, ifindex);

print_end_then_start_section("map_types",
"Scanning eBPF map types...",
"/*** eBPF map types ***/",
define_prefix);

for (i = BPF_MAP_TYPE_UNSPEC + 1; i < map_type_name_size; i++)
probe_map_type(i, define_prefix, ifindex);

print_end_then_start_section("helpers",
"Scanning eBPF helper functions...",
"/*** eBPF helper functions ***/",
define_prefix);

if (define_prefix)
printf("/*\n"
" * Use %sHAVE_PROG_TYPE_HELPER(prog_type_name, helper_name)\n"
" * to determine if <helper_name> is available for <prog_type_name>,\n"
" * e.g.\n"
" * #if %sHAVE_PROG_TYPE_HELPER(xdp, bpf_redirect)\n"
" * // do stuff with this helper\n"
" * #elif\n"
" * // use a workaround\n"
" * #endif\n"
" */\n"
"#define %sHAVE_PROG_TYPE_HELPER(prog_type, helper) \\\n"
" %sBPF__PROG_TYPE_ ## prog_type ## __HELPER_ ## helper\n",
define_prefix, define_prefix, define_prefix,
define_prefix);
for (i = BPF_PROG_TYPE_UNSPEC + 1; i < ARRAY_SIZE(prog_type_name); i++)
probe_helpers_for_progtype(i, supported_types[i],
define_prefix, ifindex);

print_end_then_start_section("misc",
"Scanning miscellaneous eBPF features...",
"/*** eBPF misc features ***/",
define_prefix);
probe_large_insn_limit(define_prefix, ifindex);
section_program_types(supported_types, define_prefix, ifindex);
section_map_types(define_prefix, ifindex);
section_helpers(supported_types, define_prefix, ifindex);
section_misc(define_prefix, ifindex);

exit_close_json:
if (json_output) {
/* End current "section" of probes */
jsonw_end_object(json_wtr);
if (json_output)
/* End root object */
jsonw_end_object(json_wtr);
}

return 0;
}
Expand Down

0 comments on commit 6b52ca4

Please sign in to comment.