test-oauth-curl.c

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/*
 * test-oauth-curl.c
 *
 * A unit test driver for libpq-oauth. This #includes oauth-curl.c, which lets
 * the tests reference static functions and other internals.
 *
 * USE_ASSERT_CHECKING is required, to make it easy for tests to wrap
 * must-succeed code as part of test setup.
 *
 * Copyright (c) 2025, PostgreSQL Global Development Group
 */
 
#include "oauth-curl.c"
 
#include <fcntl.h>
 
#ifdef USE_ASSERT_CHECKING
 
/*
 * TAP Helpers
 */
 
static int  num_tests = 0;
 
/*
 * Reports ok/not ok to the TAP stream on stdout.
 */
#define ok(OK, TEST) \
    ok_impl(OK, TEST, #OK, __FILE__, __LINE__)
 
static bool
ok_impl(bool ok, const char *test, const char *teststr, const char *file, int line)
{
    printf("%sok %d - %s\n", ok ? "" : "not ", ++num_tests, test);
 
    if (!ok)
    {
        printf("# at %s:%d:\n", file, line);
        printf("#   expression is false: %s\n", teststr);
    }
 
    return ok;
}
 
/*
 * Like ok(this == that), but with more diagnostics on failure.
 *
 * Only works on ints, but luckily that's all we need here. Note that the much
 * simpler-looking macro implementation
 *
 *     is_diag(ok(THIS == THAT, TEST), THIS, #THIS, THAT, #THAT)
 *
 * suffers from multiple evaluation of the macro arguments...
 */
#define is(THIS, THAT, TEST) \
    do { \
        int this_ = (THIS), \
            that_ = (THAT); \
        is_diag( \
            ok_impl(this_ == that_, TEST, #THIS " == " #THAT, __FILE__, __LINE__), \
            this_, #THIS, that_, #THAT \
        ); \
    } while (0)
 
static bool
is_diag(bool ok, int this, const char *thisstr, int that, const char *thatstr)
{
    if (!ok)
        printf("#   %s = %d; %s = %d\n", thisstr, this, thatstr, that);
 
    return ok;
}
 
/*
 * Utilities
 */
 
/*
 * Creates a partially-initialized async_ctx for the purposes of testing. Free
 * with free_test_actx().
 */
static struct async_ctx *
init_test_actx(void)
{
    struct async_ctx *actx;
 
    actx = calloc(1, sizeof(*actx));
    Assert(actx);
 
    actx->mux = PGINVALID_SOCKET;
    actx->timerfd = -1;
    actx->debugging = true;
 
    initPQExpBuffer(&actx->errbuf);
 
    Assert(setup_multiplexer(actx));
 
    return actx;
}
 
static void
free_test_actx(struct async_ctx *actx)
{
    termPQExpBuffer(&actx->errbuf);
 
    if (actx->mux != PGINVALID_SOCKET)
        close(actx->mux);
    if (actx->timerfd >= 0)
        close(actx->timerfd);
 
    free(actx);
}
 
static char dummy_buf[4 * 1024];    /* for fill_pipe/drain_pipe */
 
/*
 * Writes to the write side of a pipe until it won't take any more data. Returns
 * the amount written.
 */
static ssize_t
fill_pipe(int fd)
{
    int         mode;
    ssize_t     written = 0;
 
    /* Don't block. */
    Assert((mode = fcntl(fd, F_GETFL)) != -1);
    Assert(fcntl(fd, F_SETFL, mode | O_NONBLOCK) == 0);
 
    while (true)
    {
        ssize_t     w;
 
        w = write(fd, dummy_buf, sizeof(dummy_buf));
        if (w < 0)
        {
            if (errno != EAGAIN && errno != EWOULDBLOCK)
            {
                perror("write to pipe");
                written = -1;
            }
            break;
        }
 
        written += w;
    }
 
    /* Reset the descriptor flags. */
    Assert(fcntl(fd, F_SETFD, mode) == 0);
 
    return written;
}
 
/*
 * Drains the requested amount of data from the read side of a pipe.
 */
static bool
drain_pipe(int fd, ssize_t n)
{
    Assert(n > 0);
 
    while (n)
    {
        size_t      to_read = (n <= sizeof(dummy_buf)) ? n : sizeof(dummy_buf);
        ssize_t     drained;
 
        drained = read(fd, dummy_buf, to_read);
        if (drained < 0)
        {
            perror("read from pipe");
            return false;
        }
 
        n -= drained;
    }
 
    return true;
}
 
/*
 * Tests whether the multiplexer is marked ready by the deadline. This is a
 * macro so that file/line information makes sense during failures.
 *
 * NB: our current multiplexer implementations (epoll/kqueue) are *readable*
 * when the underlying libcurl sockets are *writable*. This behavior is pinned
 * here to record that expectation; PGRES_POLLING_READING is hardcoded
 * throughout the flow and would need to be changed if a new multiplexer does
 * something different.
 */
#define mux_is_ready(MUX, DEADLINE, TEST) \
    do { \
        int res_ = PQsocketPoll(MUX, 1, 0, DEADLINE); \
        Assert(res_ != -1); \
        ok(res_ > 0, "multiplexer is ready " TEST); \
    } while (0)
 
/*
 * The opposite of mux_is_ready().
 */
#define mux_is_not_ready(MUX, TEST) \
    do { \
        int res_ = PQsocketPoll(MUX, 1, 0, 0); \
        Assert(res_ != -1); \
        is(res_, 0, "multiplexer is not ready " TEST); \
    } while (0)
 
/*
 * Test Suites
 */
 
/* Per-suite timeout. Set via the PG_TEST_TIMEOUT_DEFAULT envvar. */
static pg_usec_time_t timeout_us = 180 * 1000 * 1000;
 
static void
test_set_timer(void)
{
    struct async_ctx *actx = init_test_actx();
    const pg_usec_time_t deadline = PQgetCurrentTimeUSec() + timeout_us;
 
    printf("# test_set_timer\n");
 
    /* A zero-duration timer should result in a near-immediate ready signal. */
    Assert(set_timer(actx, 0));
    mux_is_ready(actx->mux, deadline, "when timer expires");
    is(timer_expired(actx), 1, "timer_expired() returns 1 when timer expires");
 
    /* Resetting the timer far in the future should unset the ready signal. */
    Assert(set_timer(actx, INT_MAX));
    mux_is_not_ready(actx->mux, "when timer is reset to the future");
    is(timer_expired(actx), 0, "timer_expired() returns 0 with unexpired timer");
 
    /* Setting another zero-duration timer should override the previous one. */
    Assert(set_timer(actx, 0));
    mux_is_ready(actx->mux, deadline, "when timer is re-expired");
    is(timer_expired(actx), 1, "timer_expired() returns 1 when timer is re-expired");
 
    /* And disabling that timer should once again unset the ready signal. */
    Assert(set_timer(actx, -1));
    mux_is_not_ready(actx->mux, "when timer is unset");
    is(timer_expired(actx), 0, "timer_expired() returns 0 when timer is unset");
 
    {
        bool        expired;
 
        /* Make sure drain_timer_events() functions correctly as well. */
        Assert(set_timer(actx, 0));
        mux_is_ready(actx->mux, deadline, "when timer is re-expired (drain_timer_events)");
 
        Assert(drain_timer_events(actx, &expired));
        mux_is_not_ready(actx->mux, "when timer is drained after expiring");
        is(expired, 1, "drain_timer_events() reports expiration");
        is(timer_expired(actx), 0, "timer_expired() returns 0 after timer is drained");
 
        /* A second drain should do nothing. */
        Assert(drain_timer_events(actx, &expired));
        mux_is_not_ready(actx->mux, "when timer is drained a second time");
        is(expired, 0, "drain_timer_events() reports no expiration");
        is(timer_expired(actx), 0, "timer_expired() still returns 0");
    }
 
    free_test_actx(actx);
}
 
static void
test_register_socket(void)
{
    struct async_ctx *actx = init_test_actx();
    int         pipefd[2];
    int         rfd,
                wfd;
    bool        bidirectional;
 
    /* Create a local pipe for communication. */
    Assert(pipe(pipefd) == 0);
    rfd = pipefd[0];
    wfd = pipefd[1];
 
    /*
     * Some platforms (FreeBSD) implement bidirectional pipes, affecting the
     * behavior of some of these tests. Store that knowledge for later.
     */
    bidirectional = PQsocketPoll(rfd /* read */ , 0, 1 /* write */ , 0) > 0;
 
    /*
     * This suite runs twice -- once using CURL_POLL_IN/CURL_POLL_OUT for
     * read/write operations, respectively, and once using CURL_POLL_INOUT for
     * both sides.
     */
    for (int inout = 0; inout < 2; inout++)
    {
        const int   in_event = inout ? CURL_POLL_INOUT : CURL_POLL_IN;
        const int   out_event = inout ? CURL_POLL_INOUT : CURL_POLL_OUT;
        const pg_usec_time_t deadline = PQgetCurrentTimeUSec() + timeout_us;
        size_t      bidi_pipe_size = 0; /* silence compiler warnings */
 
        printf("# test_register_socket %s\n", inout ? "(INOUT)" : "");
 
        /*
         * At the start of the test, the read side should be blocked and the
         * write side should be open. (There's a mistake at the end of this
         * loop otherwise.)
         */
        Assert(PQsocketPoll(rfd, 1, 0, 0) == 0);
        Assert(PQsocketPoll(wfd, 0, 1, 0) > 0);
 
        /*
         * For bidirectional systems, emulate unidirectional behavior here by
         * filling up the "read side" of the pipe.
         */
        if (bidirectional)
            Assert((bidi_pipe_size = fill_pipe(rfd)) > 0);
 
        /* Listen on the read side. The multiplexer shouldn't be ready yet. */
        Assert(register_socket(NULL, rfd, in_event, actx, NULL) == 0);
        mux_is_not_ready(actx->mux, "when fd is not readable");
 
        /* Writing to the pipe should result in a read-ready multiplexer. */
        Assert(write(wfd, "x", 1) == 1);
        mux_is_ready(actx->mux, deadline, "when fd is readable");
 
        /*
         * Update the registration to wait on write events instead. The
         * multiplexer should be unset.
         */
        Assert(register_socket(NULL, rfd, CURL_POLL_OUT, actx, NULL) == 0);
        mux_is_not_ready(actx->mux, "when waiting for writes on readable fd");
 
        /* Re-register for read events. */
        Assert(register_socket(NULL, rfd, in_event, actx, NULL) == 0);
        mux_is_ready(actx->mux, deadline, "when waiting for reads again");
 
        /* Stop listening. The multiplexer should be unset. */
        Assert(register_socket(NULL, rfd, CURL_POLL_REMOVE, actx, NULL) == 0);
        mux_is_not_ready(actx->mux, "when readable fd is removed");
 
        /* Listen again. */
        Assert(register_socket(NULL, rfd, in_event, actx, NULL) == 0);
        mux_is_ready(actx->mux, deadline, "when readable fd is re-added");
 
        /*
         * Draining the pipe should unset the multiplexer again, once the old
         * event is cleared.
         */
        Assert(drain_pipe(rfd, 1));
        Assert(comb_multiplexer(actx));
        mux_is_not_ready(actx->mux, "when fd is drained");
 
        /* Undo any unidirectional emulation. */
        if (bidirectional)
            Assert(drain_pipe(wfd, bidi_pipe_size));
 
        /* Listen on the write side. An empty buffer should be writable. */
        Assert(register_socket(NULL, rfd, CURL_POLL_REMOVE, actx, NULL) == 0);
        Assert(register_socket(NULL, wfd, out_event, actx, NULL) == 0);
        mux_is_ready(actx->mux, deadline, "when fd is writable");
 
        /* As above, wait on read events instead. */
        Assert(register_socket(NULL, wfd, CURL_POLL_IN, actx, NULL) == 0);
        mux_is_not_ready(actx->mux, "when waiting for reads on writable fd");
 
        /* Re-register for write events. */
        Assert(register_socket(NULL, wfd, out_event, actx, NULL) == 0);
        mux_is_ready(actx->mux, deadline, "when waiting for writes again");
 
        {
            ssize_t     written;
 
            /*
             * Fill the pipe. Once the old writable event is cleared, the mux
             * should not be ready.
             */
            Assert((written = fill_pipe(wfd)) > 0);
            printf("# pipe buffer is full at %zd bytes\n", written);
 
            Assert(comb_multiplexer(actx));
            mux_is_not_ready(actx->mux, "when fd buffer is full");
 
            /* Drain the pipe again. */
            Assert(drain_pipe(rfd, written));
            mux_is_ready(actx->mux, deadline, "when fd buffer is drained");
        }
 
        /* Stop listening. */
        Assert(register_socket(NULL, wfd, CURL_POLL_REMOVE, actx, NULL) == 0);
        mux_is_not_ready(actx->mux, "when fd is removed");
 
        /* Make sure an expired timer doesn't interfere with event draining. */
        {
            bool        expired;
 
            /* Make the rfd appear unidirectional if necessary. */
            if (bidirectional)
                Assert((bidi_pipe_size = fill_pipe(rfd)) > 0);
 
            /* Set the timer and wait for it to expire. */
            Assert(set_timer(actx, 0));
            Assert(PQsocketPoll(actx->timerfd, 1, 0, deadline) > 0);
            is(timer_expired(actx), 1, "timer is expired");
 
            /* Register for read events and make the fd readable. */
            Assert(register_socket(NULL, rfd, in_event, actx, NULL) == 0);
            Assert(write(wfd, "x", 1) == 1);
            mux_is_ready(actx->mux, deadline, "when fd is readable and timer expired");
 
            /*
             * Draining the pipe should unset the multiplexer again, once the
             * old event is drained and the timer is reset.
             *
             * Order matters, since comb_multiplexer() doesn't have to remove
             * stale events when active events exist. Follow the call sequence
             * used in the code: drain the timer expiration, drain the pipe,
             * then clear the stale events.
             */
            Assert(drain_timer_events(actx, &expired));
            Assert(drain_pipe(rfd, 1));
            Assert(comb_multiplexer(actx));
 
            is(expired, 1, "drain_timer_events() reports expiration");
            is(timer_expired(actx), 0, "timer is no longer expired");
            mux_is_not_ready(actx->mux, "when fd is drained and timer reset");
 
            /* Stop listening. */
            Assert(register_socket(NULL, rfd, CURL_POLL_REMOVE, actx, NULL) == 0);
 
            /* Undo any unidirectional emulation. */
            if (bidirectional)
                Assert(drain_pipe(wfd, bidi_pipe_size));
        }
 
        /* Ensure comb_multiplexer() can handle multiple stale events. */
        {
            int         rfd2,
                        wfd2;
 
            /* Create a second local pipe. */
            Assert(pipe(pipefd) == 0);
            rfd2 = pipefd[0];
            wfd2 = pipefd[1];
 
            /* Make both rfds appear unidirectional if necessary. */
            if (bidirectional)
            {
                Assert((bidi_pipe_size = fill_pipe(rfd)) > 0);
                Assert(fill_pipe(rfd2) == bidi_pipe_size);
            }
 
            /* Register for read events on both fds, and make them readable. */
            Assert(register_socket(NULL, rfd, in_event, actx, NULL) == 0);
            Assert(register_socket(NULL, rfd2, in_event, actx, NULL) == 0);
 
            Assert(write(wfd, "x", 1) == 1);
            Assert(write(wfd2, "x", 1) == 1);
 
            mux_is_ready(actx->mux, deadline, "when two fds are readable");
 
            /*
             * Drain both fds. comb_multiplexer() should then ensure that the
             * mux is no longer readable.
             */
            Assert(drain_pipe(rfd, 1));
            Assert(drain_pipe(rfd2, 1));
            Assert(comb_multiplexer(actx));
            mux_is_not_ready(actx->mux, "when two fds are drained");
 
            /* Stop listening. */
            Assert(register_socket(NULL, rfd, CURL_POLL_REMOVE, actx, NULL) == 0);
            Assert(register_socket(NULL, rfd2, CURL_POLL_REMOVE, actx, NULL) == 0);
 
            /* Undo any unidirectional emulation. */
            if (bidirectional)
            {
                Assert(drain_pipe(wfd, bidi_pipe_size));
                Assert(drain_pipe(wfd2, bidi_pipe_size));
            }
 
            close(rfd2);
            close(wfd2);
        }
    }
 
    close(rfd);
    close(wfd);
    free_test_actx(actx);
}
 
int
main(int argc, char *argv[])
{
    const char *timeout;
 
    /* Grab the default timeout. */
    timeout = getenv("PG_TEST_TIMEOUT_DEFAULT");
    if (timeout)
    {
        int         timeout_s = atoi(timeout);
 
        if (timeout_s > 0)
            timeout_us = timeout_s * 1000 * 1000;
    }
 
    /*
     * Set up line buffering for our output, to let stderr interleave in the
     * log files.
     */
    setvbuf(stdout, NULL, PG_IOLBF, 0);
 
    test_set_timer();
    test_register_socket();
 
    printf("1..%d\n", num_tests);
    return 0;
}
 
#else                           /* !USE_ASSERT_CHECKING */
 
/*
 * Skip the test suite when we don't have assertions.
 */
int
main(int argc, char *argv[])
{
    printf("1..0 # skip: cassert is not enabled\n");
 
    return 0;
}
 
#endif                          /* USE_ASSERT_CHECKING */