123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256 |
- // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
- /* Copyright (C) 2020 Facebook */
- #include <errno.h>
- #include <linux/err.h>
- #include <stdbool.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <unistd.h>
- #include <bpf/bpf.h>
- #include <bpf/hashmap.h>
- #include "main.h"
- #include "skeleton/pid_iter.h"
- #ifdef BPFTOOL_WITHOUT_SKELETONS
- int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type)
- {
- return -ENOTSUP;
- }
- void delete_obj_refs_table(struct hashmap *map) {}
- void emit_obj_refs_plain(struct hashmap *map, __u32 id, const char *prefix) {}
- void emit_obj_refs_json(struct hashmap *map, __u32 id, json_writer_t *json_writer) {}
- #else /* BPFTOOL_WITHOUT_SKELETONS */
- #include "pid_iter.skel.h"
- static void add_ref(struct hashmap *map, struct pid_iter_entry *e)
- {
- struct hashmap_entry *entry;
- struct obj_refs *refs;
- struct obj_ref *ref;
- int err, i;
- void *tmp;
- hashmap__for_each_key_entry(map, entry, u32_as_hash_field(e->id)) {
- refs = entry->value;
- for (i = 0; i < refs->ref_cnt; i++) {
- if (refs->refs[i].pid == e->pid)
- return;
- }
- tmp = realloc(refs->refs, (refs->ref_cnt + 1) * sizeof(*ref));
- if (!tmp) {
- p_err("failed to re-alloc memory for ID %u, PID %d, COMM %s...",
- e->id, e->pid, e->comm);
- return;
- }
- refs->refs = tmp;
- ref = &refs->refs[refs->ref_cnt];
- ref->pid = e->pid;
- memcpy(ref->comm, e->comm, sizeof(ref->comm));
- refs->ref_cnt++;
- return;
- }
- /* new ref */
- refs = calloc(1, sizeof(*refs));
- if (!refs) {
- p_err("failed to alloc memory for ID %u, PID %d, COMM %s...",
- e->id, e->pid, e->comm);
- return;
- }
- refs->refs = malloc(sizeof(*refs->refs));
- if (!refs->refs) {
- free(refs);
- p_err("failed to alloc memory for ID %u, PID %d, COMM %s...",
- e->id, e->pid, e->comm);
- return;
- }
- ref = &refs->refs[0];
- ref->pid = e->pid;
- memcpy(ref->comm, e->comm, sizeof(ref->comm));
- refs->ref_cnt = 1;
- refs->has_bpf_cookie = e->has_bpf_cookie;
- refs->bpf_cookie = e->bpf_cookie;
- err = hashmap__append(map, u32_as_hash_field(e->id), refs);
- if (err)
- p_err("failed to append entry to hashmap for ID %u: %s",
- e->id, strerror(errno));
- }
- static int __printf(2, 0)
- libbpf_print_none(__maybe_unused enum libbpf_print_level level,
- __maybe_unused const char *format,
- __maybe_unused va_list args)
- {
- return 0;
- }
- int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type)
- {
- struct pid_iter_entry *e;
- char buf[4096 / sizeof(*e) * sizeof(*e)];
- struct pid_iter_bpf *skel;
- int err, ret, fd = -1, i;
- libbpf_print_fn_t default_print;
- *map = hashmap__new(hash_fn_for_key_as_id, equal_fn_for_key_as_id, NULL);
- if (IS_ERR(*map)) {
- p_err("failed to create hashmap for PID references");
- return -1;
- }
- set_max_rlimit();
- skel = pid_iter_bpf__open();
- if (!skel) {
- p_err("failed to open PID iterator skeleton");
- return -1;
- }
- skel->rodata->obj_type = type;
- /* we don't want output polluted with libbpf errors if bpf_iter is not
- * supported
- */
- default_print = libbpf_set_print(libbpf_print_none);
- err = pid_iter_bpf__load(skel);
- libbpf_set_print(default_print);
- if (err) {
- /* too bad, kernel doesn't support BPF iterators yet */
- err = 0;
- goto out;
- }
- err = pid_iter_bpf__attach(skel);
- if (err) {
- /* if we loaded above successfully, attach has to succeed */
- p_err("failed to attach PID iterator: %d", err);
- goto out;
- }
- fd = bpf_iter_create(bpf_link__fd(skel->links.iter));
- if (fd < 0) {
- err = -errno;
- p_err("failed to create PID iterator session: %d", err);
- goto out;
- }
- while (true) {
- ret = read(fd, buf, sizeof(buf));
- if (ret < 0) {
- if (errno == EAGAIN)
- continue;
- err = -errno;
- p_err("failed to read PID iterator output: %d", err);
- goto out;
- }
- if (ret == 0)
- break;
- if (ret % sizeof(*e)) {
- err = -EINVAL;
- p_err("invalid PID iterator output format");
- goto out;
- }
- ret /= sizeof(*e);
- e = (void *)buf;
- for (i = 0; i < ret; i++, e++) {
- add_ref(*map, e);
- }
- }
- err = 0;
- out:
- if (fd >= 0)
- close(fd);
- pid_iter_bpf__destroy(skel);
- return err;
- }
- void delete_obj_refs_table(struct hashmap *map)
- {
- struct hashmap_entry *entry;
- size_t bkt;
- if (!map)
- return;
- hashmap__for_each_entry(map, entry, bkt) {
- struct obj_refs *refs = entry->value;
- free(refs->refs);
- free(refs);
- }
- hashmap__free(map);
- }
- void emit_obj_refs_json(struct hashmap *map, __u32 id,
- json_writer_t *json_writer)
- {
- struct hashmap_entry *entry;
- if (hashmap__empty(map))
- return;
- hashmap__for_each_key_entry(map, entry, u32_as_hash_field(id)) {
- struct obj_refs *refs = entry->value;
- int i;
- if (refs->ref_cnt == 0)
- break;
- if (refs->has_bpf_cookie)
- jsonw_lluint_field(json_writer, "bpf_cookie", refs->bpf_cookie);
- jsonw_name(json_writer, "pids");
- jsonw_start_array(json_writer);
- for (i = 0; i < refs->ref_cnt; i++) {
- struct obj_ref *ref = &refs->refs[i];
- jsonw_start_object(json_writer);
- jsonw_int_field(json_writer, "pid", ref->pid);
- jsonw_string_field(json_writer, "comm", ref->comm);
- jsonw_end_object(json_writer);
- }
- jsonw_end_array(json_writer);
- break;
- }
- }
- void emit_obj_refs_plain(struct hashmap *map, __u32 id, const char *prefix)
- {
- struct hashmap_entry *entry;
- if (hashmap__empty(map))
- return;
- hashmap__for_each_key_entry(map, entry, u32_as_hash_field(id)) {
- struct obj_refs *refs = entry->value;
- int i;
- if (refs->ref_cnt == 0)
- break;
- if (refs->has_bpf_cookie)
- printf("\n\tbpf_cookie %llu", (unsigned long long) refs->bpf_cookie);
- printf("%s", prefix);
- for (i = 0; i < refs->ref_cnt; i++) {
- struct obj_ref *ref = &refs->refs[i];
- printf("%s%s(%d)", i == 0 ? "" : ", ", ref->comm, ref->pid);
- }
- break;
- }
- }
- #endif
|