Provide the ability to delay/reorder DTLS packets.

Add a test that delays the client CCS, resulting in it arriving after the
client Finished message.

diff --git a/regress/lib/libssl/dtls/dtlstest.c b/regress/lib/libssl/dtls/dtlstest.c
index 194728e..d7f2f4b 100644 (file)
--- a/regress/lib/libssl/dtls/dtlstest.c
+++ b/regress/lib/libssl/dtls/dtlstest.c
@@ -1,6 +1,6 @@
-/* $OpenBSD: dtlstest.c,v 1.9 2021/06/18 18:26:38 jsing Exp $ */
+/* $OpenBSD: dtlstest.c,v 1.10 2021/06/19 15:33:37 jsing Exp $ */
 /*
- * Copyright (c) 2020 Joel Sing <jsing@openbsd.org>
+ * Copyright (c) 2020, 2021 Joel Sing <jsing@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -47,12 +47,19 @@ hexdump(const unsigned char *buf, size_t len)
                fprintf(stderr, "\n");
 }
 
-#define BIO_C_DROP_PACKET      1000
-#define BIO_C_DROP_RANDOM      1001
+#define BIO_C_DELAY_COUNT      1000
+#define BIO_C_DELAY_FLUSH      1001
+#define BIO_C_DELAY_PACKET     1002
+#define BIO_C_DROP_PACKET      1003
+#define BIO_C_DROP_RANDOM      1004
 
 struct bio_packet_monkey_ctx {
+       unsigned int delay_count;
+       unsigned int delay_mask;
        unsigned int drop_rand;
        unsigned int drop_mask;
+       uint8_t *delayed_msg;
+       size_t delayed_msg_len;
 };
 
 static int
@@ -80,11 +87,33 @@ bio_packet_monkey_free(BIO *bio)
                return 1;
 
        ctx = bio->ptr;
+       free(ctx->delayed_msg);
        free(ctx);
 
        return 1;
 }
 
+static int
+bio_packet_monkey_delay_flush(BIO *bio)
+{
+       struct bio_packet_monkey_ctx *ctx = bio->ptr;
+
+       if (ctx->delayed_msg == NULL)
+               return 1;
+
+       if (debug)
+               fprintf(stderr, "DEBUG: flushing delayed packet...\n");
+       if (debug > 1)
+               hexdump(ctx->delayed_msg, ctx->delayed_msg_len);
+
+       BIO_write(bio->next_bio, ctx->delayed_msg, ctx->delayed_msg_len);
+
+       free(ctx->delayed_msg);
+       ctx->delayed_msg = NULL;
+
+       return BIO_ctrl(bio->next_bio, BIO_CTRL_FLUSH, 0, NULL);
+}
+
 static long
 bio_packet_monkey_ctrl(BIO *bio, int cmd, long num, void *ptr)
 {
@@ -93,6 +122,21 @@ bio_packet_monkey_ctrl(BIO *bio, int cmd, long num, void *ptr)
        ctx = bio->ptr;
 
        switch (cmd) {
+       case BIO_C_DELAY_COUNT:
+               if (num < 1 || num > 31)
+                       return 0;
+               ctx->delay_count = num;
+               return 1;
+
+       case BIO_C_DELAY_FLUSH:
+               return bio_packet_monkey_delay_flush(bio);
+
+       case BIO_C_DELAY_PACKET:
+               if (num < 1 || num > 31)
+                       return 0;
+               ctx->delay_mask |= 1 << ((unsigned int)num - 1);
+               return 1;
+
        case BIO_C_DROP_PACKET:
                if (num < 1 || num > 31)
                        return 0;
@@ -123,6 +167,13 @@ bio_packet_monkey_read(BIO *bio, char *out, int out_len)
 
        ret = BIO_read(bio->next_bio, out, out_len);
 
+       if (ret > 0) {
+               if (debug)
+                       fprintf(stderr, "DEBUG: read packet...\n");
+               if (debug > 1)
+                       hexdump(out, ret);
+       }
+
        BIO_clear_retry_flags(bio);
        if (ret <= 0 && BIO_should_retry(bio->next_bio))
                BIO_set_retry_read(bio);
@@ -134,27 +185,68 @@ static int
 bio_packet_monkey_write(BIO *bio, const char *in, int in_len)
 {
        struct bio_packet_monkey_ctx *ctx = bio->ptr;
-       int drop = 0;
+       const char *label = "writing";
+       int delay = 0, drop = 0;
        int ret;
 
        if (ctx == NULL || bio->next_bio == NULL)
                return 0;
 
+       if (ctx->delayed_msg != NULL && ctx->delay_count > 0)
+               ctx->delay_count--;
+
+       if (ctx->delayed_msg != NULL && ctx->delay_count == 0) {
+               if (debug)
+                       fprintf(stderr, "DEBUG: writing delayed packet...\n");
+               if (debug > 1)
+                       hexdump(ctx->delayed_msg, ctx->delayed_msg_len);
+
+               ret = BIO_write(bio->next_bio, ctx->delayed_msg,
+                   ctx->delayed_msg_len);
+
+               BIO_clear_retry_flags(bio);
+               if (ret <= 0 && BIO_should_retry(bio->next_bio)) {
+                       BIO_set_retry_write(bio);
+                       return (ret);
+               }
+
+               free(ctx->delayed_msg);
+               ctx->delayed_msg = NULL;
+       }
+               
+       if (ctx->delay_mask > 0) {
+               delay = ctx->delay_mask & 1;
+               ctx->delay_mask >>= 1;
+       }
        if (ctx->drop_rand > 0) {
                drop = arc4random_uniform(ctx->drop_rand) == 0;
        } else if (ctx->drop_mask > 0) {
                drop = ctx->drop_mask & 1;
                ctx->drop_mask >>= 1;
        }
-       if (debug) {
-               fprintf(stderr, "DEBUG: %s packet...\n",
-                   drop ? "dropping" : "writing");
-               if (debug > 1)
-                       hexdump(in, in_len);
-       }
+
+       if (delay)
+               label = "delaying";
+       if (drop)
+               label = "dropping";
+       if (debug)
+               fprintf(stderr, "DEBUG: %s packet...\n", label);
+       if (debug > 1)
+               hexdump(in, in_len);
+
        if (drop)
                return in_len;
 
+       if (delay) {
+               if (ctx->delayed_msg != NULL)
+                       return 0;
+               if ((ctx->delayed_msg = calloc(1, in_len)) == NULL)
+                       return 0;
+               memcpy(ctx->delayed_msg, in, in_len);
+               ctx->delayed_msg_len = in_len;
+               return in_len;
+       }
+
        ret = BIO_write(bio->next_bio, in, in_len);
 
        BIO_clear_retry_flags(bio);
@@ -193,6 +285,23 @@ BIO_new_packet_monkey(void)
        return BIO_new(BIO_f_packet_monkey());
 }
 
+static int
+BIO_packet_monkey_delay(BIO *bio, int num, int count)
+{
+       if (!BIO_ctrl(bio, BIO_C_DELAY_COUNT, count, NULL))
+               return 0;
+
+       return BIO_ctrl(bio, BIO_C_DELAY_PACKET, num, NULL);
+}
+
+#if 0
+static int
+BIO_packet_monkey_delay_flush(BIO *bio)
+{
+       return BIO_ctrl(bio, BIO_C_DELAY_FLUSH, 0, NULL);
+}
+#endif
+
 static int
 BIO_packet_monkey_drop(BIO *bio, int num)
 {
@@ -519,14 +628,22 @@ do_client_server_loop(SSL *client, ssl_func client_func, SSL *server,
        return client_done && server_done;
 }
 
+#define MAX_PACKET_DELAYS 32
 #define MAX_PACKET_DROPS 32
 
+struct dtls_delay {
+       uint8_t packet;
+       uint8_t count;
+};
+
 struct dtls_test {
        const unsigned char *desc;
        long mtu;
        long ssl_options;
        int client_bbio_off;
        int server_bbio_off;
+       struct dtls_delay client_delays[MAX_PACKET_DELAYS];
+       struct dtls_delay server_delays[MAX_PACKET_DELAYS];
        uint8_t client_drops[MAX_PACKET_DROPS];
        uint8_t server_drops[MAX_PACKET_DROPS];
 };
@@ -621,12 +738,20 @@ static const struct dtls_test dtls_tests[] = {
                .client_bbio_off = 1,
                .client_drops = { 4 },
        },
+       {
+               /* Send CCS after client Finished. */
+               .desc = "DTLS with delayed client CCS",
+               .ssl_options = 0,
+               .client_bbio_off = 1,
+               .client_delays = { { 3, 2 } },
+       },
 };
 
 #define N_DTLS_TESTS (sizeof(dtls_tests) / sizeof(*dtls_tests))
 
 static void
-dtlstest_packet_monkey(SSL *ssl, const uint8_t drops[])
+dtlstest_packet_monkey(SSL *ssl, const struct dtls_delay delays[],
+    const uint8_t drops[])
 {
        BIO *bio_monkey;
        BIO *bio;
@@ -635,6 +760,14 @@ dtlstest_packet_monkey(SSL *ssl, const uint8_t drops[])
        if ((bio_monkey = BIO_new_packet_monkey()) == NULL)
                errx(1, "packet monkey");
 
+       for (i = 0; i < MAX_PACKET_DELAYS; i++) {
+               if (delays[i].packet == 0)
+                       break;
+               if (!BIO_packet_monkey_delay(bio_monkey, delays[i].packet,
+                   delays[i].count))
+                       errx(1, "delay failure");
+       }
+
        for (i = 0; i < MAX_PACKET_DROPS; i++) {
                if (drops[i] == 0)
                        break;
@@ -676,8 +809,8 @@ dtlstest(const struct dtls_test *dt)
        if (dt->server_bbio_off)
                SSL_set_info_callback(server, dtls_info_callback);
 
-       dtlstest_packet_monkey(client, dt->client_drops);
-       dtlstest_packet_monkey(server, dt->server_drops);
+       dtlstest_packet_monkey(client, dt->client_delays, dt->client_drops);
+       dtlstest_packet_monkey(server, dt->server_delays, dt->server_drops);
 
        pfd[0].fd = client_sock;
        pfd[0].events = POLLOUT;