diff options
Diffstat (limited to 'tools/bpf')
| -rw-r--r-- | tools/bpf/bpftool/feature.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c index cedc44a61c6e..4a2867439ab7 100644 --- a/tools/bpf/bpftool/feature.c +++ b/tools/bpf/bpftool/feature.c @@ -48,6 +48,30 @@ print_bool_feature(const char *feat_name, const char *plain_name, bool res) printf("%s is %savailable\n", plain_name, res ? "" : "NOT "); } +static void print_kernel_option(const char *name, const char *value) +{ + char *endptr; + int res; + + if (json_output) { + if (!value) { + jsonw_null_field(json_wtr, name); + return; + } + errno = 0; + res = strtol(value, &endptr, 0); + if (!errno && *endptr == '\n') + jsonw_int_field(json_wtr, name, res); + else + jsonw_string_field(json_wtr, name, value); + } else { + if (value) + printf("%s is set to %s\n", name, value); + else + printf("%s is not set\n", name); + } +} + static void print_start_section(const char *json_title, const char *plain_title) { @@ -208,6 +232,163 @@ static void probe_jit_limit(void) } } +static char *get_kernel_config_option(FILE *fd, const char *option) +{ + size_t line_n = 0, optlen = strlen(option); + char *res, *strval, *line = NULL; + ssize_t n; + + rewind(fd); + while ((n = getline(&line, &line_n, fd)) > 0) { + if (strncmp(line, option, optlen)) + continue; + /* Check we have at least '=', value, and '\n' */ + if (strlen(line) < optlen + 3) + continue; + if (*(line + optlen) != '=') + continue; + + /* Trim ending '\n' */ + line[strlen(line) - 1] = '\0'; + + /* Copy and return config option value */ + strval = line + optlen + 1; + res = strdup(strval); + free(line); + return res; + } + free(line); + + return NULL; +} + +static void probe_kernel_image_config(void) +{ + static const char * const options[] = { + /* Enable BPF */ + "CONFIG_BPF", + /* Enable bpf() syscall */ + "CONFIG_BPF_SYSCALL", + /* Does selected architecture support eBPF JIT compiler */ + "CONFIG_HAVE_EBPF_JIT", + /* Compile eBPF JIT compiler */ + "CONFIG_BPF_JIT", + /* Avoid compiling eBPF interpreter (use JIT only) */ + "CONFIG_BPF_JIT_ALWAYS_ON", + + /* cgroups */ + "CONFIG_CGROUPS", + /* BPF programs attached to cgroups */ + "CONFIG_CGROUP_BPF", + /* bpf_get_cgroup_classid() helper */ + "CONFIG_CGROUP_NET_CLASSID", + /* bpf_skb_{,ancestor_}cgroup_id() helpers */ + "CONFIG_SOCK_CGROUP_DATA", + + /* Tracing: attach BPF to kprobes, tracepoints, etc. */ + "CONFIG_BPF_EVENTS", + /* Kprobes */ + "CONFIG_KPROBE_EVENTS", + /* Uprobes */ + "CONFIG_UPROBE_EVENTS", + /* Tracepoints */ + "CONFIG_TRACING", + /* Syscall tracepoints */ + "CONFIG_FTRACE_SYSCALLS", + /* bpf_override_return() helper support for selected arch */ + "CONFIG_FUNCTION_ERROR_INJECTION", + /* bpf_override_return() helper */ + "CONFIG_BPF_KPROBE_OVERRIDE", + + /* Network */ + "CONFIG_NET", + /* AF_XDP sockets */ + "CONFIG_XDP_SOCKETS", + /* BPF_PROG_TYPE_LWT_* and related helpers */ + "CONFIG_LWTUNNEL_BPF", + /* BPF_PROG_TYPE_SCHED_ACT, TC (traffic control) actions */ + "CONFIG_NET_ACT_BPF", + /* BPF_PROG_TYPE_SCHED_CLS, TC filters */ + "CONFIG_NET_CLS_BPF", + /* TC clsact qdisc */ + "CONFIG_NET_CLS_ACT", + /* Ingress filtering with TC */ + "CONFIG_NET_SCH_INGRESS", + /* bpf_skb_get_xfrm_state() helper */ + "CONFIG_XFRM", + /* bpf_get_route_realm() helper */ + "CONFIG_IP_ROUTE_CLASSID", + /* BPF_PROG_TYPE_LWT_SEG6_LOCAL and related helpers */ + "CONFIG_IPV6_SEG6_BPF", + /* BPF_PROG_TYPE_LIRC_MODE2 and related helpers */ + "CONFIG_BPF_LIRC_MODE2", + /* BPF stream parser and BPF socket maps */ + "CONFIG_BPF_STREAM_PARSER", + /* xt_bpf module for passing BPF programs to netfilter */ + "CONFIG_NETFILTER_XT_MATCH_BPF", + /* bpfilter back-end for iptables */ + "CONFIG_BPFILTER", + /* bpftilter module with "user mode helper" */ + "CONFIG_BPFILTER_UMH", + + /* test_bpf module for BPF tests */ + "CONFIG_TEST_BPF", + }; + char *value, *buf = NULL; + struct utsname utsn; + char path[PATH_MAX]; + size_t i, n; + ssize_t ret; + FILE *fd; + + if (uname(&utsn)) + goto no_config; + + snprintf(path, sizeof(path), "/boot/config-%s", utsn.release); + + fd = fopen(path, "r"); + if (!fd && errno == ENOENT) { + /* Some distributions put the config file at /proc/config, give + * it a try. + * Sometimes it is also at /proc/config.gz but we do not try + * this one for now, it would require linking against libz. + */ + fd = fopen("/proc/config", "r"); + } + if (!fd) { + p_info("skipping kernel config, can't open file: %s", + strerror(errno)); + goto no_config; + } + /* Sanity checks */ + ret = getline(&buf, &n, fd); + ret = getline(&buf, &n, fd); + if (!buf || !ret) { + p_info("skipping kernel config, can't read from file: %s", + strerror(errno)); + free(buf); + goto no_config; + } + if (strcmp(buf, "# Automatically generated file; DO NOT EDIT.\n")) { + p_info("skipping kernel config, can't find correct file"); + free(buf); + goto no_config; + } + free(buf); + + for (i = 0; i < ARRAY_SIZE(options); i++) { + value = get_kernel_config_option(fd, options[i]); + print_kernel_option(options[i], value); + free(value); + } + fclose(fd); + return; + +no_config: + for (i = 0; i < ARRAY_SIZE(options); i++) + print_kernel_option(options[i], NULL); +} + static bool probe_bpf_syscall(void) { bool res; @@ -268,6 +449,7 @@ static int do_probe(int argc, char **argv) } else { p_info("/* procfs not mounted, skipping related probes */"); } + probe_kernel_image_config(); if (json_output) jsonw_end_object(json_wtr); else |