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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <unistd.h>
#include "errno-util.h"
#include "fd-util.h"
#include "fuzz.h"
#include "hexdecoct.h"
#include "iovec-util.h"
#include "varlink.h"
#include "log.h"
static FILE *null = NULL;
static int method_something(Varlink *v, JsonVariant *p, VarlinkMethodFlags flags, void *userdata) {
json_variant_dump(p, JSON_FORMAT_NEWLINE|JSON_FORMAT_PRETTY, null, NULL);
return 0;
}
static int reply_callback(Varlink *v, JsonVariant *p, const char *error_id, VarlinkReplyFlags flags, void *userdata) {
json_variant_dump(p, JSON_FORMAT_NEWLINE|JSON_FORMAT_PRETTY, null, NULL);
return 0;
}
static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
struct iovec *iov = ASSERT_PTR(userdata);
bool write_eof = false, read_eof = false;
assert(s);
assert(fd >= 0);
if ((revents & (EPOLLOUT|EPOLLHUP|EPOLLERR)) && iov->iov_len > 0) {
ssize_t n;
/* never write more than 143 bytes a time, to make broken up recv()s on the other side more
* likely, and thus test some additional code paths. */
n = send(fd, iov->iov_base, MIN(iov->iov_len, 143U), MSG_NOSIGNAL|MSG_DONTWAIT);
if (n < 0) {
if (ERRNO_IS_DISCONNECT(errno))
write_eof = true;
else
assert_se(errno == EAGAIN);
} else
iovec_increment(iov, 1, n);
}
if (revents & EPOLLIN) {
char c[137];
ssize_t n;
n = recv(fd, c, sizeof(c), MSG_DONTWAIT);
if (n < 0) {
if (ERRNO_IS_DISCONNECT(errno))
read_eof = true;
else
assert_se(errno == EAGAIN);
} else if (n == 0)
read_eof = true;
else
hexdump(null, c, (size_t) n);
}
/* After we wrote everything we could turn off EPOLLOUT. And if we reached read EOF too turn off the
* whole thing. */
if (write_eof || iov->iov_len == 0) {
if (read_eof)
assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0);
else
assert_se(sd_event_source_set_io_events(s, EPOLLIN) >= 0);
}
return 0;
}
static int idle_callback(sd_event_source *s, void *userdata) {
assert(s);
/* Called as idle callback when there's nothing else to do anymore */
sd_event_exit(sd_event_source_get_event(s), 0);
return 0;
}
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
struct iovec server_iov = IOVEC_MAKE((void*) data, size), client_iov = IOVEC_MAKE((void*) data, size);
/* Important: the declaration order matters here! we want that the fds are closed on return after the
* event sources, hence we declare the fds first, the event sources second */
_cleanup_close_pair_ int server_pair[2] = EBADF_PAIR, client_pair[2] = EBADF_PAIR;
_cleanup_(sd_event_source_unrefp) sd_event_source *idle_event_source = NULL,
*server_event_source = NULL, *client_event_source = NULL;
_cleanup_(varlink_server_unrefp) VarlinkServer *s = NULL;
_cleanup_(varlink_flush_close_unrefp) Varlink *c = NULL;
_cleanup_(sd_event_unrefp) sd_event *e = NULL;
fuzz_setup_logging();
assert_se(null = fopen("/dev/null", "we"));
assert_se(sd_event_default(&e) >= 0);
/* Test one: write the data as method call to a server */
assert_se(socketpair(AF_UNIX, SOCK_STREAM, 0, server_pair) >= 0);
assert_se(varlink_server_new(&s, 0) >= 0);
assert_se(varlink_server_set_description(s, "myserver") >= 0);
assert_se(varlink_server_attach_event(s, e, 0) >= 0);
assert_se(varlink_server_add_connection(s, server_pair[0], NULL) >= 0);
TAKE_FD(server_pair[0]);
assert_se(varlink_server_bind_method(s, "io.test.DoSomething", method_something) >= 0);
assert_se(sd_event_add_io(e, &server_event_source, server_pair[1], EPOLLIN|EPOLLOUT, io_callback, &server_iov) >= 0);
/* Test two: write the data as method response to a client */
assert_se(socketpair(AF_UNIX, SOCK_STREAM, 0, client_pair) >= 0);
assert_se(varlink_connect_fd(&c, client_pair[0]) >= 0);
TAKE_FD(client_pair[0]);
assert_se(varlink_set_description(c, "myclient") >= 0);
assert_se(varlink_attach_event(c, e, 0) >= 0);
assert_se(varlink_bind_reply(c, reply_callback) >= 0);
assert_se(varlink_invoke(c, "io.test.DoSomething", NULL) >= 0);
assert_se(sd_event_add_io(e, &client_event_source, client_pair[1], EPOLLIN|EPOLLOUT, io_callback, &client_iov) >= 0);
assert_se(sd_event_add_defer(e, &idle_event_source, idle_callback, NULL) >= 0);
assert_se(sd_event_source_set_priority(idle_event_source, SD_EVENT_PRIORITY_IDLE) >= 0);
assert_se(sd_event_loop(e) >= 0);
null = safe_fclose(null);
return 0;
}
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