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1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2/* Copyright (C) 2020 Facebook */
3#include <errno.h>
4#include <linux/err.h>
5#include <stdbool.h>
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9#include <unistd.h>
10
11#include <bpf/bpf.h>
12#include <bpf/hashmap.h>
13
14#include "main.h"
15#include "skeleton/pid_iter.h"
16
17#ifdef BPFTOOL_WITHOUT_SKELETONS
18
19int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type)
20{
21 return -ENOTSUP;
22}
23void delete_obj_refs_table(struct hashmap *map) {}
24void emit_obj_refs_plain(struct hashmap *map, __u32 id, const char *prefix) {}
25void emit_obj_refs_json(struct hashmap *map, __u32 id, json_writer_t *json_writer) {}
26
27#else /* BPFTOOL_WITHOUT_SKELETONS */
28
29#include "pid_iter.skel.h"
30
31static void add_ref(struct hashmap *map, struct pid_iter_entry *e)
32{
33 struct hashmap_entry *entry;
34 struct obj_refs *refs;
35 struct obj_ref *ref;
36 int err, i;
37 void *tmp;
38
39 hashmap__for_each_key_entry(map, entry, e->id) {
40 refs = entry->pvalue;
41
42 for (i = 0; i < refs->ref_cnt; i++) {
43 if (refs->refs[i].pid == e->pid)
44 return;
45 }
46
47 tmp = realloc(refs->refs, (refs->ref_cnt + 1) * sizeof(*ref));
48 if (!tmp) {
49 p_err("failed to re-alloc memory for ID %u, PID %d, COMM %s...",
50 e->id, e->pid, e->comm);
51 return;
52 }
53 refs->refs = tmp;
54 ref = &refs->refs[refs->ref_cnt];
55 ref->pid = e->pid;
56 memcpy(ref->comm, e->comm, sizeof(ref->comm));
57 ref->comm[sizeof(ref->comm) - 1] = '\0';
58 refs->ref_cnt++;
59
60 return;
61 }
62
63 /* new ref */
64 refs = calloc(1, sizeof(*refs));
65 if (!refs) {
66 p_err("failed to alloc memory for ID %u, PID %d, COMM %s...",
67 e->id, e->pid, e->comm);
68 return;
69 }
70
71 refs->refs = malloc(sizeof(*refs->refs));
72 if (!refs->refs) {
73 free(refs);
74 p_err("failed to alloc memory for ID %u, PID %d, COMM %s...",
75 e->id, e->pid, e->comm);
76 return;
77 }
78 ref = &refs->refs[0];
79 ref->pid = e->pid;
80 memcpy(ref->comm, e->comm, sizeof(ref->comm));
81 ref->comm[sizeof(ref->comm) - 1] = '\0';
82 refs->ref_cnt = 1;
83 refs->has_bpf_cookie = e->has_bpf_cookie;
84 refs->bpf_cookie = e->bpf_cookie;
85
86 err = hashmap__append(map, e->id, refs);
87 if (err)
88 p_err("failed to append entry to hashmap for ID %u: %s",
89 e->id, strerror(errno));
90}
91
92static int __printf(2, 0)
93libbpf_print_none(__maybe_unused enum libbpf_print_level level,
94 __maybe_unused const char *format,
95 __maybe_unused va_list args)
96{
97 return 0;
98}
99
100int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type)
101{
102 struct pid_iter_entry *e;
103 char buf[4096 / sizeof(*e) * sizeof(*e)];
104 struct pid_iter_bpf *skel;
105 int err, ret, fd = -1, i;
106
107 *map = hashmap__new(hash_fn_for_key_as_id, equal_fn_for_key_as_id, NULL);
108 if (IS_ERR(*map)) {
109 p_err("failed to create hashmap for PID references");
110 return -1;
111 }
112 set_max_rlimit();
113
114 skel = pid_iter_bpf__open();
115 if (!skel) {
116 p_err("failed to open PID iterator skeleton");
117 return -1;
118 }
119
120 skel->rodata->obj_type = type;
121
122 if (!verifier_logs) {
123 libbpf_print_fn_t default_print;
124
125 /* Unless debug information is on, we don't want the output to
126 * be polluted with libbpf errors if bpf_iter is not supported.
127 */
128 default_print = libbpf_set_print(libbpf_print_none);
129 err = pid_iter_bpf__load(skel);
130 libbpf_set_print(default_print);
131 } else {
132 err = pid_iter_bpf__load(skel);
133 }
134 if (err) {
135 /* too bad, kernel doesn't support BPF iterators yet */
136 err = 0;
137 goto out;
138 }
139 err = pid_iter_bpf__attach(skel);
140 if (err) {
141 /* if we loaded above successfully, attach has to succeed */
142 p_err("failed to attach PID iterator: %d", err);
143 goto out;
144 }
145
146 fd = bpf_iter_create(bpf_link__fd(skel->links.iter));
147 if (fd < 0) {
148 err = -errno;
149 p_err("failed to create PID iterator session: %d", err);
150 goto out;
151 }
152
153 while (true) {
154 ret = read(fd, buf, sizeof(buf));
155 if (ret < 0) {
156 if (errno == EAGAIN)
157 continue;
158 err = -errno;
159 p_err("failed to read PID iterator output: %d", err);
160 goto out;
161 }
162 if (ret == 0)
163 break;
164 if (ret % sizeof(*e)) {
165 err = -EINVAL;
166 p_err("invalid PID iterator output format");
167 goto out;
168 }
169 ret /= sizeof(*e);
170
171 e = (void *)buf;
172 for (i = 0; i < ret; i++, e++) {
173 add_ref(*map, e);
174 }
175 }
176 err = 0;
177out:
178 if (fd >= 0)
179 close(fd);
180 pid_iter_bpf__destroy(skel);
181 return err;
182}
183
184void delete_obj_refs_table(struct hashmap *map)
185{
186 struct hashmap_entry *entry;
187 size_t bkt;
188
189 if (!map)
190 return;
191
192 hashmap__for_each_entry(map, entry, bkt) {
193 struct obj_refs *refs = entry->pvalue;
194
195 free(refs->refs);
196 free(refs);
197 }
198
199 hashmap__free(map);
200}
201
202void emit_obj_refs_json(struct hashmap *map, __u32 id,
203 json_writer_t *json_writer)
204{
205 struct hashmap_entry *entry;
206
207 if (hashmap__empty(map))
208 return;
209
210 hashmap__for_each_key_entry(map, entry, id) {
211 struct obj_refs *refs = entry->pvalue;
212 int i;
213
214 if (refs->ref_cnt == 0)
215 break;
216
217 if (refs->has_bpf_cookie)
218 jsonw_lluint_field(json_writer, "bpf_cookie", refs->bpf_cookie);
219
220 jsonw_name(json_writer, "pids");
221 jsonw_start_array(json_writer);
222 for (i = 0; i < refs->ref_cnt; i++) {
223 struct obj_ref *ref = &refs->refs[i];
224
225 jsonw_start_object(json_writer);
226 jsonw_int_field(json_writer, "pid", ref->pid);
227 jsonw_string_field(json_writer, "comm", ref->comm);
228 jsonw_end_object(json_writer);
229 }
230 jsonw_end_array(json_writer);
231 break;
232 }
233}
234
235void emit_obj_refs_plain(struct hashmap *map, __u32 id, const char *prefix)
236{
237 struct hashmap_entry *entry;
238
239 if (hashmap__empty(map))
240 return;
241
242 hashmap__for_each_key_entry(map, entry, id) {
243 struct obj_refs *refs = entry->pvalue;
244 int i;
245
246 if (refs->ref_cnt == 0)
247 break;
248
249 if (refs->has_bpf_cookie)
250 printf("\n\tbpf_cookie %llu", (unsigned long long) refs->bpf_cookie);
251
252 printf("%s", prefix);
253 for (i = 0; i < refs->ref_cnt; i++) {
254 struct obj_ref *ref = &refs->refs[i];
255
256 printf("%s%s(%d)", i == 0 ? "" : ", ", ref->comm, ref->pid);
257 }
258 break;
259 }
260}
261
262
263#endif
1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2/* Copyright (C) 2020 Facebook */
3#include <errno.h>
4#include <stdbool.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <string.h>
8#include <unistd.h>
9#include <bpf/bpf.h>
10
11#include "main.h"
12#include "skeleton/pid_iter.h"
13
14#ifdef BPFTOOL_WITHOUT_SKELETONS
15
16int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type)
17{
18 return -ENOTSUP;
19}
20void delete_obj_refs_table(struct obj_refs_table *table) {}
21void emit_obj_refs_plain(struct obj_refs_table *table, __u32 id, const char *prefix) {}
22void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_writer) {}
23
24#else /* BPFTOOL_WITHOUT_SKELETONS */
25
26#include "pid_iter.skel.h"
27
28static void add_ref(struct obj_refs_table *table, struct pid_iter_entry *e)
29{
30 struct obj_refs *refs;
31 struct obj_ref *ref;
32 void *tmp;
33 int i;
34
35 hash_for_each_possible(table->table, refs, node, e->id) {
36 if (refs->id != e->id)
37 continue;
38
39 for (i = 0; i < refs->ref_cnt; i++) {
40 if (refs->refs[i].pid == e->pid)
41 return;
42 }
43
44 tmp = realloc(refs->refs, (refs->ref_cnt + 1) * sizeof(*ref));
45 if (!tmp) {
46 p_err("failed to re-alloc memory for ID %u, PID %d, COMM %s...",
47 e->id, e->pid, e->comm);
48 return;
49 }
50 refs->refs = tmp;
51 ref = &refs->refs[refs->ref_cnt];
52 ref->pid = e->pid;
53 memcpy(ref->comm, e->comm, sizeof(ref->comm));
54 refs->ref_cnt++;
55
56 return;
57 }
58
59 /* new ref */
60 refs = calloc(1, sizeof(*refs));
61 if (!refs) {
62 p_err("failed to alloc memory for ID %u, PID %d, COMM %s...",
63 e->id, e->pid, e->comm);
64 return;
65 }
66
67 refs->id = e->id;
68 refs->refs = malloc(sizeof(*refs->refs));
69 if (!refs->refs) {
70 free(refs);
71 p_err("failed to alloc memory for ID %u, PID %d, COMM %s...",
72 e->id, e->pid, e->comm);
73 return;
74 }
75 ref = &refs->refs[0];
76 ref->pid = e->pid;
77 memcpy(ref->comm, e->comm, sizeof(ref->comm));
78 refs->ref_cnt = 1;
79 hash_add(table->table, &refs->node, e->id);
80}
81
82static int __printf(2, 0)
83libbpf_print_none(__maybe_unused enum libbpf_print_level level,
84 __maybe_unused const char *format,
85 __maybe_unused va_list args)
86{
87 return 0;
88}
89
90int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type)
91{
92 char buf[4096];
93 struct pid_iter_bpf *skel;
94 struct pid_iter_entry *e;
95 int err, ret, fd = -1, i;
96 libbpf_print_fn_t default_print;
97
98 hash_init(table->table);
99 set_max_rlimit();
100
101 skel = pid_iter_bpf__open();
102 if (!skel) {
103 p_err("failed to open PID iterator skeleton");
104 return -1;
105 }
106
107 skel->rodata->obj_type = type;
108
109 /* we don't want output polluted with libbpf errors if bpf_iter is not
110 * supported
111 */
112 default_print = libbpf_set_print(libbpf_print_none);
113 err = pid_iter_bpf__load(skel);
114 libbpf_set_print(default_print);
115 if (err) {
116 /* too bad, kernel doesn't support BPF iterators yet */
117 err = 0;
118 goto out;
119 }
120 err = pid_iter_bpf__attach(skel);
121 if (err) {
122 /* if we loaded above successfully, attach has to succeed */
123 p_err("failed to attach PID iterator: %d", err);
124 goto out;
125 }
126
127 fd = bpf_iter_create(bpf_link__fd(skel->links.iter));
128 if (fd < 0) {
129 err = -errno;
130 p_err("failed to create PID iterator session: %d", err);
131 goto out;
132 }
133
134 while (true) {
135 ret = read(fd, buf, sizeof(buf));
136 if (ret < 0) {
137 if (errno == EAGAIN)
138 continue;
139 err = -errno;
140 p_err("failed to read PID iterator output: %d", err);
141 goto out;
142 }
143 if (ret == 0)
144 break;
145 if (ret % sizeof(*e)) {
146 err = -EINVAL;
147 p_err("invalid PID iterator output format");
148 goto out;
149 }
150 ret /= sizeof(*e);
151
152 e = (void *)buf;
153 for (i = 0; i < ret; i++, e++) {
154 add_ref(table, e);
155 }
156 }
157 err = 0;
158out:
159 if (fd >= 0)
160 close(fd);
161 pid_iter_bpf__destroy(skel);
162 return err;
163}
164
165void delete_obj_refs_table(struct obj_refs_table *table)
166{
167 struct obj_refs *refs;
168 struct hlist_node *tmp;
169 unsigned int bkt;
170
171 hash_for_each_safe(table->table, bkt, tmp, refs, node) {
172 hash_del(&refs->node);
173 free(refs->refs);
174 free(refs);
175 }
176}
177
178void emit_obj_refs_json(struct obj_refs_table *table, __u32 id,
179 json_writer_t *json_writer)
180{
181 struct obj_refs *refs;
182 struct obj_ref *ref;
183 int i;
184
185 if (hash_empty(table->table))
186 return;
187
188 hash_for_each_possible(table->table, refs, node, id) {
189 if (refs->id != id)
190 continue;
191 if (refs->ref_cnt == 0)
192 break;
193
194 jsonw_name(json_writer, "pids");
195 jsonw_start_array(json_writer);
196 for (i = 0; i < refs->ref_cnt; i++) {
197 ref = &refs->refs[i];
198 jsonw_start_object(json_writer);
199 jsonw_int_field(json_writer, "pid", ref->pid);
200 jsonw_string_field(json_writer, "comm", ref->comm);
201 jsonw_end_object(json_writer);
202 }
203 jsonw_end_array(json_writer);
204 break;
205 }
206}
207
208void emit_obj_refs_plain(struct obj_refs_table *table, __u32 id, const char *prefix)
209{
210 struct obj_refs *refs;
211 struct obj_ref *ref;
212 int i;
213
214 if (hash_empty(table->table))
215 return;
216
217 hash_for_each_possible(table->table, refs, node, id) {
218 if (refs->id != id)
219 continue;
220 if (refs->ref_cnt == 0)
221 break;
222
223 printf("%s", prefix);
224 for (i = 0; i < refs->ref_cnt; i++) {
225 ref = &refs->refs[i];
226 printf("%s%s(%d)", i == 0 ? "" : ", ", ref->comm, ref->pid);
227 }
228 break;
229 }
230}
231
232
233#endif