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.

1 files changed, 147 insertions, 14 deletions

diff --git a/src/regress/lib/libssl/dtls/dtlstest.c b/src/regress/lib/libssl/dtls/dtlstest.c
index 194728e26b..d7f2f4b2de 100644
--- a/src/regress/lib/libssl/dtls/dtlstest.c
+++ b/src/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);
@@ -194,6 +286,23 @@ BIO_new_packet_monkey(void)
 }
 
 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)
 {
         return BIO_ctrl(bio, BIO_C_DROP_PACKET, num, NULL);
@@ -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;