close(fd);
 }
 
-#define MESSAGES_CNT 7
-#define MSG_EOR_IDX (MESSAGES_CNT / 2)
+#define SOCK_BUF_SIZE (2 * 1024 * 1024)
+#define MAX_MSG_SIZE (32 * 1024)
+
 static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
 {
+       unsigned long curr_hash;
+       int page_size;
+       int msg_count;
        int fd;
 
        fd = vsock_seqpacket_connect(opts->peer_cid, 1234);
                exit(EXIT_FAILURE);
        }
 
-       /* Send several messages, one with MSG_EOR flag */
-       for (int i = 0; i < MESSAGES_CNT; i++)
-               send_byte(fd, 1, (i == MSG_EOR_IDX) ? MSG_EOR : 0);
+       /* Wait, until receiver sets buffer size. */
+       control_expectln("SRVREADY");
+
+       curr_hash = 0;
+       page_size = getpagesize();
+       msg_count = SOCK_BUF_SIZE / MAX_MSG_SIZE;
+
+       for (int i = 0; i < msg_count; i++) {
+               ssize_t send_size;
+               size_t buf_size;
+               int flags;
+               void *buf;
+
+               /* Use "small" buffers and "big" buffers. */
+               if (i & 1)
+                       buf_size = page_size +
+                                       (rand() % (MAX_MSG_SIZE - page_size));
+               else
+                       buf_size = 1 + (rand() % page_size);
+
+               buf = malloc(buf_size);
+
+               if (!buf) {
+                       perror("malloc");
+                       exit(EXIT_FAILURE);
+               }
+
+               memset(buf, rand() & 0xff, buf_size);
+               /* Set at least one MSG_EOR + some random. */
+               if (i == (msg_count / 2) || (rand() & 1)) {
+                       flags = MSG_EOR;
+                       curr_hash++;
+               } else {
+                       flags = 0;
+               }
+
+               send_size = send(fd, buf, buf_size, flags);
+
+               if (send_size < 0) {
+                       perror("send");
+                       exit(EXIT_FAILURE);
+               }
+
+               if (send_size != buf_size) {
+                       fprintf(stderr, "Invalid send size\n");
+                       exit(EXIT_FAILURE);
+               }
+
+               /*
+                * Hash sum is computed at both client and server in
+                * the same way:
+                * H += hash('message data')
+                * Such hash "controls" both data integrity and message
+                * bounds. After data exchange, both sums are compared
+                * using control socket, and if message bounds wasn't
+                * broken - two values must be equal.
+                */
+               curr_hash += hash_djb2(buf, buf_size);
+               free(buf);
+       }
 
        control_writeln("SENDDONE");
+       control_writeulong(curr_hash);
        close(fd);
 }
 
 static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
 {
+       unsigned long sock_buf_size;
+       unsigned long remote_hash;
+       unsigned long curr_hash;
        int fd;
-       char buf[16];
+       char buf[MAX_MSG_SIZE];
        struct msghdr msg = {0};
        struct iovec iov = {0};
 
                exit(EXIT_FAILURE);
        }
 
+       sock_buf_size = SOCK_BUF_SIZE;
+
+       if (setsockopt(fd, AF_VSOCK, SO_VM_SOCKETS_BUFFER_MAX_SIZE,
+                      &sock_buf_size, sizeof(sock_buf_size))) {
+               perror("setsockopt(SO_VM_SOCKETS_BUFFER_MAX_SIZE)");
+               exit(EXIT_FAILURE);
+       }
+
+       if (setsockopt(fd, AF_VSOCK, SO_VM_SOCKETS_BUFFER_SIZE,
+                      &sock_buf_size, sizeof(sock_buf_size))) {
+               perror("setsockopt(SO_VM_SOCKETS_BUFFER_SIZE)");
+               exit(EXIT_FAILURE);
+       }
+
+       /* Ready to receive data. */
+       control_writeln("SRVREADY");
+       /* Wait, until peer sends whole data. */
        control_expectln("SENDDONE");
        iov.iov_base = buf;
        iov.iov_len = sizeof(buf);
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
 
-       for (int i = 0; i < MESSAGES_CNT; i++) {
-               if (recvmsg(fd, &msg, 0) != 1) {
-                       perror("message bound violated");
-                       exit(EXIT_FAILURE);
-               }
+       curr_hash = 0;
 
-               if ((i == MSG_EOR_IDX) ^ !!(msg.msg_flags & MSG_EOR)) {
-                       perror("MSG_EOR");
+       while (1) {
+               ssize_t recv_size;
+
+               recv_size = recvmsg(fd, &msg, 0);
+
+               if (!recv_size)
+                       break;
+
+               if (recv_size < 0) {
+                       perror("recvmsg");
                        exit(EXIT_FAILURE);
                }
+
+               if (msg.msg_flags & MSG_EOR)
+                       curr_hash++;
+
+               curr_hash += hash_djb2(msg.msg_iov[0].iov_base, recv_size);
        }
 
        close(fd);
+       remote_hash = control_readulong();
+
+       if (curr_hash != remote_hash) {
+               fprintf(stderr, "Message bounds broken\n");
+               exit(EXIT_FAILURE);
+       }
 }
 
 #define MESSAGE_TRUNC_SZ 32
        tv.tv_usec = 0;
 
        if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (void *)&tv, sizeof(tv)) == -1) {
-               perror("setsockopt 'SO_RCVTIMEO'");
+               perror("setsockopt(SO_RCVTIMEO)");
                exit(EXIT_FAILURE);
        }
 
 
        if (setsockopt(fd, SOL_SOCKET, SO_RCVLOWAT,
                       &lowat_val, sizeof(lowat_val))) {
-               perror("setsockopt");
+               perror("setsockopt(SO_RCVLOWAT)");
                exit(EXIT_FAILURE);
        }
 
                .peer_cid = VMADDR_CID_ANY,
        };
 
+       srand(time(NULL));
        init_signals();
 
        for (;;) {