Line data Source code
1 : /* SPDX-License-Identifier: LGPL-2.1+ */
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 :
26 2 : static int method_something(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
27 2 : _cleanup_(json_variant_unrefp) JsonVariant *ret = NULL;
28 : JsonVariant *a, *b;
29 : intmax_t x, y;
30 : int r;
31 :
32 2 : a = json_variant_by_key(parameters, "a");
33 2 : if (!a)
34 0 : return varlink_error(link, "io.test.BadParameters", NULL);
35 :
36 2 : x = json_variant_integer(a);
37 :
38 2 : b = json_variant_by_key(parameters, "b");
39 2 : if (!b)
40 0 : return varlink_error(link, "io.test.BadParameters", NULL);
41 :
42 2 : y = json_variant_integer(b);
43 :
44 2 : r = json_build(&ret, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("sum", JSON_BUILD_INTEGER(x + y))));
45 2 : if (r < 0)
46 0 : return r;
47 :
48 2 : return varlink_reply(link, ret);
49 : }
50 :
51 1 : static int method_done(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
52 :
53 1 : if (++n_done == 2)
54 1 : sd_event_exit(varlink_get_event(link), EXIT_FAILURE);
55 :
56 1 : return 0;
57 : }
58 :
59 1 : static int reply(Varlink *link, JsonVariant *parameters, const char *error_id, VarlinkReplyFlags flags, void *userdata) {
60 : JsonVariant *sum;
61 :
62 1 : sum = json_variant_by_key(parameters, "sum");
63 :
64 1 : assert_se(json_variant_integer(sum) == 7+22);
65 :
66 1 : if (++n_done == 2)
67 0 : sd_event_exit(varlink_get_event(link), EXIT_FAILURE);
68 :
69 1 : return 0;
70 : }
71 :
72 131 : static int on_connect(VarlinkServer *s, Varlink *link, void *userdata) {
73 131 : uid_t uid = UID_INVALID;
74 :
75 131 : assert(s);
76 131 : assert(link);
77 :
78 131 : assert_se(varlink_get_peer_uid(link, &uid) >= 0);
79 131 : assert_se(getuid() == uid);
80 :
81 131 : return 0;
82 : }
83 :
84 1 : 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 1 : log_debug("Over reply triggered with error: %s", strna(error_id));
90 1 : assert_se(streq(error_id, VARLINK_ERROR_DISCONNECTED));
91 1 : sd_event_exit(varlink_get_event(link), 0);
92 :
93 1 : return 0;
94 : }
95 :
96 1 : static void flood_test(const char *address) {
97 1 : _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
98 1 : _cleanup_(sd_event_unrefp) sd_event *e = NULL;
99 1 : _cleanup_free_ Varlink **connections = NULL;
100 : size_t k;
101 1 : char x = 'x';
102 :
103 1 : log_debug("Flooding server...");
104 :
105 : /* Block the main event loop while we flood */
106 1 : assert_se(write(block_write_fd, &x, sizeof(x)) == sizeof(x));
107 :
108 1 : assert_se(sd_event_default(&e) >= 0);
109 :
110 : /* Flood the server with connections */
111 1 : assert_se(connections = new0(Varlink*, OVERLOAD_CONNECTIONS));
112 334 : for (k = 0; k < OVERLOAD_CONNECTIONS; k++) {
113 333 : _cleanup_free_ char *t = NULL;
114 333 : log_debug("connection %zu", k);
115 333 : assert_se(varlink_connect_address(connections + k, address) >= 0);
116 :
117 333 : assert_se(asprintf(&t, "flood-%zu", k) >= 0);
118 333 : assert_se(varlink_set_description(connections[k], t) >= 0);
119 333 : assert_se(varlink_attach_event(connections[k], e, k) >= 0);
120 333 : 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 1 : log_debug("Creating overload connection...");
125 1 : assert_se(varlink_connect_address(&c, address) >= 0);
126 1 : assert_se(varlink_set_description(c, "overload-client") >= 0);
127 1 : assert_se(varlink_attach_event(c, e, k) >= 0);
128 1 : assert_se(varlink_bind_reply(c, overload_reply) >= 0);
129 1 : assert_se(varlink_invokeb(c, "io.test.Overload", JSON_BUILD_OBJECT(JSON_BUILD_PAIR("foo", JSON_BUILD_STRING("bar")))) >= 0);
130 :
131 : /* Unblock it */
132 1 : log_debug("Unblocking server...");
133 1 : block_write_fd = safe_close(block_write_fd);
134 :
135 : /* This loop will terminate as soon as the overload reply callback is called */
136 1 : assert_se(sd_event_loop(e) >= 0);
137 :
138 : /* And close all connections again */
139 334 : for (k = 0; k < OVERLOAD_CONNECTIONS; k++)
140 333 : connections[k] = varlink_unref(connections[k]);
141 1 : }
142 :
143 1 : static void *thread(void *arg) {
144 1 : _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
145 2 : _cleanup_(json_variant_unrefp) JsonVariant *i = NULL;
146 1 : JsonVariant *o = NULL;
147 : const char *e;
148 :
149 1 : 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 1 : assert_se(varlink_connect_address(&c, arg) >= 0);
153 1 : assert_se(varlink_set_description(c, "thread-client") >= 0);
154 :
155 1 : assert_se(varlink_call(c, "io.test.DoSomething", i, &o, &e, NULL) >= 0);
156 1 : assert_se(json_variant_integer(json_variant_by_key(o, "sum")) == 88 + 99);
157 1 : assert_se(!e);
158 :
159 1 : 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 1 : assert_se(streq_ptr(json_variant_string(json_variant_by_key(o, "method")), "io.test.IDontExist"));
161 1 : assert_se(streq(e, VARLINK_ERROR_METHOD_NOT_FOUND));
162 :
163 1 : flood_test(arg);
164 :
165 1 : assert_se(varlink_send(c, "io.test.Done", NULL) >= 0);
166 :
167 1 : return NULL;
168 : }
169 :
170 1 : static int block_fd_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
171 : char c;
172 :
173 1 : assert_se(fd_nonblock(fd, false) >= 0);
174 :
175 1 : 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 1 : assert_se(read(fd, &c, sizeof(c)) == 0);
179 :
180 1 : assert_se(fd_nonblock(fd, true) >= 0);
181 :
182 1 : assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0);
183 :
184 1 : return 0;
185 : }
186 :
187 1 : int main(int argc, char *argv[]) {
188 1 : _cleanup_(sd_event_source_unrefp) sd_event_source *block_event = NULL;
189 1 : _cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL;
190 1 : _cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
191 1 : _cleanup_(rm_rf_physical_and_freep) char *tmpdir = NULL;
192 1 : _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
193 1 : _cleanup_(sd_event_unrefp) sd_event *e = NULL;
194 2 : _cleanup_(close_pairp) int block_fds[2] = { -1, -1 };
195 : pthread_t t;
196 : const char *sp;
197 :
198 1 : log_set_max_level(LOG_DEBUG);
199 1 : log_open();
200 :
201 1 : assert_se(mkdtemp_malloc("/tmp/varlink-test-XXXXXX", &tmpdir) >= 0);
202 5 : sp = strjoina(tmpdir, "/socket");
203 :
204 1 : assert_se(sd_event_default(&e) >= 0);
205 :
206 1 : assert_se(pipe2(block_fds, O_NONBLOCK|O_CLOEXEC) >= 0);
207 1 : assert_se(sd_event_add_io(e, &block_event, block_fds[0], EPOLLIN, block_fd_handler, NULL) >= 0);
208 1 : assert_se(sd_event_source_set_priority(block_event, SD_EVENT_PRIORITY_IMPORTANT) >= 0);
209 1 : block_write_fd = TAKE_FD(block_fds[1]);
210 :
211 1 : assert_se(varlink_server_new(&s, VARLINK_SERVER_ACCOUNT_UID) >= 0);
212 1 : assert_se(varlink_server_set_description(s, "our-server") >= 0);
213 :
214 1 : assert_se(varlink_server_bind_method(s, "io.test.DoSomething", method_something) >= 0);
215 1 : assert_se(varlink_server_bind_method(s, "io.test.Done", method_done) >= 0);
216 1 : assert_se(varlink_server_bind_connect(s, on_connect) >= 0);
217 1 : assert_se(varlink_server_listen_address(s, sp, 0600) >= 0);
218 1 : assert_se(varlink_server_attach_event(s, e, 0) >= 0);
219 1 : assert_se(varlink_server_set_connections_max(s, OVERLOAD_CONNECTIONS) >= 0);
220 :
221 1 : assert_se(varlink_connect_address(&c, sp) >= 0);
222 1 : assert_se(varlink_set_description(c, "main-client") >= 0);
223 1 : assert_se(varlink_bind_reply(c, reply) >= 0);
224 :
225 1 : 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 1 : assert_se(varlink_invoke(c, "io.test.DoSomething", v) >= 0);
229 :
230 1 : assert_se(varlink_attach_event(c, e, 0) >= 0);
231 :
232 1 : assert_se(pthread_create(&t, NULL, thread, (void*) sp) == 0);
233 :
234 1 : assert_se(sd_event_loop(e) >= 0);
235 :
236 1 : assert_se(pthread_join(t, NULL) == 0);
237 :
238 1 : return 0;
239 : }
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