1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #include <fcntl.h>
4 #include <poll.h>
5 #include <pthread.h>
6
7 #include "sd-event.h"
8
9 #include "fd-util.h"
10 #include "json.h"
11 #include "rm-rf.h"
12 #include "strv.h"
13 #include "tmpfile-util.h"
14 #include "user-util.h"
15 #include "varlink.h"
16
17 /* Let's pick some high value, that is higher than the largest listen() backlog, but leaves enough room below
18 the typical RLIMIT_NOFILE value of 1024 so that we can process both sides of each socket in our
19 process. Or in other words: "OVERLOAD_CONNECTIONS * 2 + x < 1024" should hold, for some small x that
20 should cover any auxiliary fds, the listener server fds, stdin/stdout/stderr and whatever else. */
21 #define OVERLOAD_CONNECTIONS 333
22
23 static int n_done = 0;
24 static int block_write_fd = -1;
25
method_something(Varlink * link,JsonVariant * parameters,VarlinkMethodFlags flags,void * userdata)26 static int method_something(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
27 _cleanup_(json_variant_unrefp) JsonVariant *ret = NULL;
28 JsonVariant *a, *b;
29 int64_t x, y;
30 int r;
31
32 a = json_variant_by_key(parameters, "a");
33 if (!a)
34 return varlink_error(link, "io.test.BadParameters", NULL);
35
36 x = json_variant_integer(a);
37
38 b = json_variant_by_key(parameters, "b");
39 if (!b)
40 return varlink_error(link, "io.test.BadParameters", NULL);
41
42 y = json_variant_integer(b);
43
44 r = json_build(&ret, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("sum", JSON_BUILD_INTEGER(x + y))));
45 if (r < 0)
46 return r;
47
48 return varlink_reply(link, ret);
49 }
50
method_done(Varlink * link,JsonVariant * parameters,VarlinkMethodFlags flags,void * userdata)51 static int method_done(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
52
53 if (++n_done == 2)
54 sd_event_exit(varlink_get_event(link), EXIT_FAILURE);
55
56 return 0;
57 }
58
reply(Varlink * link,JsonVariant * parameters,const char * error_id,VarlinkReplyFlags flags,void * userdata)59 static int reply(Varlink *link, JsonVariant *parameters, const char *error_id, VarlinkReplyFlags flags, void *userdata) {
60 JsonVariant *sum;
61
62 sum = json_variant_by_key(parameters, "sum");
63
64 assert_se(json_variant_integer(sum) == 7+22);
65
66 if (++n_done == 2)
67 sd_event_exit(varlink_get_event(link), EXIT_FAILURE);
68
69 return 0;
70 }
71
on_connect(VarlinkServer * s,Varlink * link,void * userdata)72 static int on_connect(VarlinkServer *s, Varlink *link, void *userdata) {
73 uid_t uid = UID_INVALID;
74
75 assert_se(s);
76 assert_se(link);
77
78 assert_se(varlink_get_peer_uid(link, &uid) >= 0);
79 assert_se(getuid() == uid);
80
81 return 0;
82 }
83
overload_reply(Varlink * link,JsonVariant * parameters,const char * error_id,VarlinkReplyFlags flags,void * userdata)84 static int overload_reply(Varlink *link, JsonVariant *parameters, const char *error_id, VarlinkReplyFlags flags, void *userdata) {
85
86 /* This method call reply should always be called with a disconnection, since the method call should
87 * be talking to an overloaded server */
88
89 log_debug("Over reply triggered with error: %s", strna(error_id));
90 assert_se(streq(error_id, VARLINK_ERROR_DISCONNECTED));
91 sd_event_exit(varlink_get_event(link), 0);
92
93 return 0;
94 }
95
flood_test(const char * address)96 static void flood_test(const char *address) {
97 _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
98 _cleanup_(sd_event_unrefp) sd_event *e = NULL;
99 _cleanup_free_ Varlink **connections = NULL;
100 size_t k;
101 char x = 'x';
102
103 log_debug("Flooding server...");
104
105 /* Block the main event loop while we flood */
106 assert_se(write(block_write_fd, &x, sizeof(x)) == sizeof(x));
107
108 assert_se(sd_event_default(&e) >= 0);
109
110 /* Flood the server with connections */
111 assert_se(connections = new0(Varlink*, OVERLOAD_CONNECTIONS));
112 for (k = 0; k < OVERLOAD_CONNECTIONS; k++) {
113 _cleanup_free_ char *t = NULL;
114 log_debug("connection %zu", k);
115 assert_se(varlink_connect_address(connections + k, address) >= 0);
116
117 assert_se(asprintf(&t, "flood-%zu", k) >= 0);
118 assert_se(varlink_set_description(connections[k], t) >= 0);
119 assert_se(varlink_attach_event(connections[k], e, k) >= 0);
120 assert_se(varlink_sendb(connections[k], "io.test.Rubbish", JSON_BUILD_OBJECT(JSON_BUILD_PAIR("id", JSON_BUILD_INTEGER(k)))) >= 0);
121 }
122
123 /* Then, create one more, which should fail */
124 log_debug("Creating overload connection...");
125 assert_se(varlink_connect_address(&c, address) >= 0);
126 assert_se(varlink_set_description(c, "overload-client") >= 0);
127 assert_se(varlink_attach_event(c, e, k) >= 0);
128 assert_se(varlink_bind_reply(c, overload_reply) >= 0);
129 assert_se(varlink_invokeb(c, "io.test.Overload", JSON_BUILD_OBJECT(JSON_BUILD_PAIR("foo", JSON_BUILD_CONST_STRING("bar")))) >= 0);
130
131 /* Unblock it */
132 log_debug("Unblocking server...");
133 block_write_fd = safe_close(block_write_fd);
134
135 /* This loop will terminate as soon as the overload reply callback is called */
136 assert_se(sd_event_loop(e) >= 0);
137
138 /* And close all connections again */
139 for (k = 0; k < OVERLOAD_CONNECTIONS; k++)
140 connections[k] = varlink_unref(connections[k]);
141 }
142
thread(void * arg)143 static void *thread(void *arg) {
144 _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
145 _cleanup_(json_variant_unrefp) JsonVariant *i = NULL;
146 JsonVariant *o = NULL;
147 const char *e;
148
149 assert_se(json_build(&i, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("a", JSON_BUILD_INTEGER(88)),
150 JSON_BUILD_PAIR("b", JSON_BUILD_INTEGER(99)))) >= 0);
151
152 assert_se(varlink_connect_address(&c, arg) >= 0);
153 assert_se(varlink_set_description(c, "thread-client") >= 0);
154
155 assert_se(varlink_call(c, "io.test.DoSomething", i, &o, &e, NULL) >= 0);
156 assert_se(json_variant_integer(json_variant_by_key(o, "sum")) == 88 + 99);
157 assert_se(!e);
158
159 assert_se(varlink_callb(c, "io.test.IDontExist", &o, &e, NULL, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("x", JSON_BUILD_REAL(5.5)))) >= 0);
160 assert_se(streq_ptr(json_variant_string(json_variant_by_key(o, "method")), "io.test.IDontExist"));
161 assert_se(streq(e, VARLINK_ERROR_METHOD_NOT_FOUND));
162
163 flood_test(arg);
164
165 assert_se(varlink_send(c, "io.test.Done", NULL) >= 0);
166
167 return NULL;
168 }
169
block_fd_handler(sd_event_source * s,int fd,uint32_t revents,void * userdata)170 static int block_fd_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
171 char c;
172
173 assert_se(fd_nonblock(fd, false) >= 0);
174
175 assert_se(read(fd, &c, sizeof(c)) == sizeof(c));
176 /* When a character is written to this pipe we'll block until the pipe is closed. */
177
178 assert_se(read(fd, &c, sizeof(c)) == 0);
179
180 assert_se(fd_nonblock(fd, true) >= 0);
181
182 assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0);
183
184 return 0;
185 }
186
main(int argc,char * argv[])187 int main(int argc, char *argv[]) {
188 _cleanup_(sd_event_source_unrefp) sd_event_source *block_event = NULL;
189 _cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL;
190 _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
191 _cleanup_(rm_rf_physical_and_freep) char *tmpdir = NULL;
192 _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
193 _cleanup_(sd_event_unrefp) sd_event *e = NULL;
194 _cleanup_(close_pairp) int block_fds[2] = { -1, -1 };
195 pthread_t t;
196 const char *sp;
197
198 log_set_max_level(LOG_DEBUG);
199 log_open();
200
201 assert_se(mkdtemp_malloc("/tmp/varlink-test-XXXXXX", &tmpdir) >= 0);
202 sp = strjoina(tmpdir, "/socket");
203
204 assert_se(sd_event_default(&e) >= 0);
205
206 assert_se(pipe2(block_fds, O_NONBLOCK|O_CLOEXEC) >= 0);
207 assert_se(sd_event_add_io(e, &block_event, block_fds[0], EPOLLIN, block_fd_handler, NULL) >= 0);
208 assert_se(sd_event_source_set_priority(block_event, SD_EVENT_PRIORITY_IMPORTANT) >= 0);
209 block_write_fd = TAKE_FD(block_fds[1]);
210
211 assert_se(varlink_server_new(&s, VARLINK_SERVER_ACCOUNT_UID) >= 0);
212 assert_se(varlink_server_set_description(s, "our-server") >= 0);
213
214 assert_se(varlink_server_bind_method(s, "io.test.DoSomething", method_something) >= 0);
215 assert_se(varlink_server_bind_method(s, "io.test.Done", method_done) >= 0);
216 assert_se(varlink_server_bind_connect(s, on_connect) >= 0);
217 assert_se(varlink_server_listen_address(s, sp, 0600) >= 0);
218 assert_se(varlink_server_attach_event(s, e, 0) >= 0);
219 assert_se(varlink_server_set_connections_max(s, OVERLOAD_CONNECTIONS) >= 0);
220
221 assert_se(varlink_connect_address(&c, sp) >= 0);
222 assert_se(varlink_set_description(c, "main-client") >= 0);
223 assert_se(varlink_bind_reply(c, reply) >= 0);
224
225 assert_se(json_build(&v, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("a", JSON_BUILD_INTEGER(7)),
226 JSON_BUILD_PAIR("b", JSON_BUILD_INTEGER(22)))) >= 0);
227
228 assert_se(varlink_invoke(c, "io.test.DoSomething", v) >= 0);
229
230 assert_se(varlink_attach_event(c, e, 0) >= 0);
231
232 assert_se(pthread_create(&t, NULL, thread, (void*) sp) == 0);
233
234 assert_se(sd_event_loop(e) >= 0);
235
236 assert_se(pthread_join(t, NULL) == 0);
237
238 return 0;
239 }
240