1
2
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
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
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 struct pid_iter_entry *e;
93 char buf[4096 / sizeof(*e) * sizeof(*e)];
94 struct pid_iter_bpf *skel;
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
110
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
117 err = 0;
118 goto out;
119 }
120 err = pid_iter_bpf__attach(skel);
121 if (err) {
122
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
234
