Add an ability to set the SSL read buffer size

This capability is required for read pipelining. We will only read in as
many records as will fit in the read buffer (and the network can provide
in one go). The bigger the buffer the more records we can process in
parallel.
Reviewed-by: NTim Hudson <tjh@openssl.org>

apps/s_client.c

@@ -656,7 +656,7 @@ typedef enum OPTION_choice {
     OPT_CHAINCAFILE, OPT_VERIFYCAFILE, OPT_NEXTPROTONEG, OPT_ALPN,
     OPT_SERVERINFO, OPT_STARTTLS, OPT_SERVERNAME,
     OPT_USE_SRTP, OPT_KEYMATEXPORT, OPT_KEYMATEXPORTLEN, OPT_SMTPHOST,
-    OPT_ASYNC, OPT_SPLIT_SEND_FRAG, OPT_MAX_PIPELINES,
+    OPT_ASYNC, OPT_SPLIT_SEND_FRAG, OPT_MAX_PIPELINES, OPT_READ_BUF,
     OPT_V_ENUM,
     OPT_X_ENUM,
     OPT_S_ENUM,
@@ -766,6 +766,8 @@ OPTIONS s_client_options[] = {
      "Size used to split data for encrypt/decrypt pipelines"},
     {"max_pipelines", OPT_MAX_PIPELINES, 'n',
      "Maximum number of encrypt/decrypt pipelines to be used"},
+    {"read_buf", OPT_READ_BUF, 'n',
+     "Default read buffer size to be used for connections"},
     OPT_S_OPTIONS,
     OPT_V_OPTIONS,
     OPT_X_OPTIONS,
@@ -896,6 +898,7 @@ int s_client_main(int argc, char **argv)
     int socket_family = AF_UNSPEC, socket_type = SOCK_STREAM;
     int starttls_proto = PROTO_OFF, crl_format = FORMAT_PEM, crl_download = 0;
     int write_tty, read_tty, write_ssl, read_ssl, tty_on, ssl_pending;
+    int read_buf_len = 0;
     int fallback_scsv = 0;
     long socket_mtu = 0, randamt = 0;
     OPTION_CHOICE o;
@@ -1393,6 +1396,9 @@ int s_client_main(int argc, char **argv)
         case OPT_MAX_PIPELINES:
             max_pipelines = atoi(opt_arg());
             break;
+        case OPT_READ_BUF:
+            read_buf_len = atoi(opt_arg());
+            break;
         }
     }
     argc = opt_num_rest();
@@ -1573,6 +1579,10 @@ int s_client_main(int argc, char **argv)
         SSL_CTX_set_max_pipelines(ctx, max_pipelines);
     }
 
+    if (read_buf_len > 0) {
+        SSL_CTX_set_default_read_buffer_len(ctx, read_buf_len);
+    }
+
     if (!config_ctx(cctx, ssl_args, ctx))
         goto end;
 

apps/s_server.c

@@ -809,8 +809,8 @@ typedef enum OPTION_choice {
     OPT_QUIET, OPT_BRIEF, OPT_NO_DHE,
     OPT_NO_RESUME_EPHEMERAL, OPT_PSK_HINT, OPT_PSK, OPT_SRPVFILE,
     OPT_SRPUSERSEED, OPT_REV, OPT_WWW, OPT_UPPER_WWW, OPT_HTTP, OPT_ASYNC,
-    OPT_SSL_CONFIG, OPT_SPLIT_SEND_FRAG, OPT_MAX_PIPELINES, OPT_SSL3,
-    OPT_TLS1_2, OPT_TLS1_1, OPT_TLS1, OPT_DTLS, OPT_DTLS1,
+    OPT_SSL_CONFIG, OPT_SPLIT_SEND_FRAG, OPT_MAX_PIPELINES, OPT_READ_BUF,
+    OPT_SSL3, OPT_TLS1_2, OPT_TLS1_1, OPT_TLS1, OPT_DTLS, OPT_DTLS1,
     OPT_DTLS1_2, OPT_TIMEOUT, OPT_MTU, OPT_CHAIN, OPT_LISTEN,
     OPT_ID_PREFIX, OPT_RAND, OPT_SERVERNAME, OPT_SERVERNAME_FATAL,
     OPT_CERT2, OPT_KEY2, OPT_NEXTPROTONEG, OPT_ALPN,
@@ -946,6 +946,8 @@ OPTIONS s_server_options[] = {
      "Size used to split data for encrypt/decrypt pipelines"},
     {"max_pipelines", OPT_MAX_PIPELINES, 'n',
      "Maximum number of encrypt/decrypt pipelines to be used"},
+    {"read_buf", OPT_READ_BUF, 'n',
+     "Default read buffer size to be used for connections"},
     OPT_S_OPTIONS,
     OPT_V_OPTIONS,
     OPT_X_OPTIONS,
@@ -1049,6 +1051,7 @@ int s_server_main(int argc, char *argv[])
     X509 *s_cert2 = NULL;
     tlsextctx tlsextcbp = { NULL, NULL, SSL_TLSEXT_ERR_ALERT_WARNING };
     const char *ssl_config = NULL;
+    int read_buf_len = 0;
 #ifndef OPENSSL_NO_NEXTPROTONEG
     const char *next_proto_neg_in = NULL;
     tlsextnextprotoctx next_proto = { NULL, 0 };
@@ -1521,6 +1524,10 @@ int s_server_main(int argc, char *argv[])
         case OPT_MAX_PIPELINES:
             max_pipelines = atoi(opt_arg());
             break;
+        case OPT_READ_BUF:
+            read_buf_len = atoi(opt_arg());
+            break;
+
         }
     }
     argc = opt_num_rest();
@@ -1753,6 +1760,10 @@ int s_server_main(int argc, char *argv[])
         SSL_CTX_set_max_pipelines(ctx, max_pipelines);
     }
 
+    if (read_buf_len > 0) {
+        SSL_CTX_set_default_read_buffer_len(ctx, read_buf_len);
+    }
+
 #ifndef OPENSSL_NO_SRTP
     if (srtp_profiles != NULL) {
         /* Returns 0 on success! */

include/openssl/ssl.h

@@ -1808,6 +1808,9 @@ __owur int SSL_get_ex_data_X509_STORE_CTX_idx(void);
 # define SSL_set_max_pipelines(ssl,m) \
         SSL_ctrl(ssl,SSL_CTRL_SET_MAX_PIPELINES,m,NULL)
 
+void SSL_CTX_set_default_read_buffer_len(SSL_CTX *ctx, size_t len);
+void SSL_set_default_read_buffer_len(SSL *s, size_t len);
+
      /* NB: the keylength is only applicable when is_export is true */
 # ifndef OPENSSL_NO_DH
 void SSL_CTX_set_tmp_dh_callback(SSL_CTX *ctx,

ssl/record/rec_layer_s3.c

@@ -241,6 +241,16 @@ int ssl3_pending(const SSL *s)
     return num;
 }
 
+void SSL_CTX_set_default_read_buffer_len(SSL_CTX *ctx, size_t len)
+{
+    ctx->default_read_buf_len = len;
+}
+
+void SSL_set_default_read_buffer_len(SSL *s, size_t len)
+{
+    SSL3_BUFFER_set_default_len(RECORD_LAYER_get_rbuf(&s->rlayer), len);
+}
+
 const char *SSL_rstate_string_long(const SSL *s)
 {
     const char *str;

ssl/record/record.h

@@ -118,6 +118,8 @@
 typedef struct ssl3_buffer_st {
     /* at least SSL3_RT_MAX_PACKET_SIZE bytes, see ssl3_setup_buffers() */
     unsigned char *buf;
+    /* default buffer size (or 0 if no default set) */
+    size_t default_len;
     /* buffer size */
     size_t len;
     /* where to 'copy from' */

ssl/record/record_locl.h

@@ -162,6 +162,7 @@ void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 #define SSL3_BUFFER_set_offset(b, o)        ((b)->offset = (o))
 #define SSL3_BUFFER_add_offset(b, o)        ((b)->offset += (o))
 #define SSL3_BUFFER_is_initialised(b)       ((b)->buf != NULL)
+#define SSL3_BUFFER_set_default_len(b, l)   ((b)->default_len = (l))
 
 void SSL3_BUFFER_clear(SSL3_BUFFER *b);
 void SSL3_BUFFER_set_data(SSL3_BUFFER *b, const unsigned char *d, int n);

ssl/record/ssl3_buffer.c

@@ -120,16 +120,13 @@ void SSL3_BUFFER_set_data(SSL3_BUFFER *b, const unsigned char *d, int n)
 }
 
 /*
- * Clear the contents of an SSL3_BUFFER but retain any memory allocated
+ * Clear the contents of an SSL3_BUFFER but retain any memory allocated. Also
+ * retains the default_len setting
  */
 void SSL3_BUFFER_clear(SSL3_BUFFER *b)
 {
-    unsigned char *buf = b->buf;
-    size_t len = b->len;
-
-    memset(b, 0, sizeof(*b));
-    b->buf = buf;
-    b->len = len;
+    b->offset = 0;
+    b->left = 0;
 }
 
 void SSL3_BUFFER_release(SSL3_BUFFER *b)
@@ -162,6 +159,8 @@ int ssl3_setup_read_buffer(SSL *s)
         if (ssl_allow_compression(s))
             len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
 #endif
+        if (b->default_len > len)
+            len = b->default_len;
         if ((p = OPENSSL_malloc(len)) == NULL)
             goto err;
         b->buf = p;

ssl/ssl_lib.c

@@ -674,6 +674,8 @@ SSL *SSL_new(SSL_CTX *ctx)
     s->max_pipelines = ctx->max_pipelines;
     if (s->max_pipelines > 1)
         RECORD_LAYER_set_read_ahead(&s->rlayer, 1);
+    if (ctx->default_read_buf_len > 0)
+        SSL_set_default_read_buffer_len(s, ctx->default_read_buf_len);
 
     CRYPTO_add(&ctx->references, 1, CRYPTO_LOCK_SSL_CTX);
     s->ctx = ctx;

ssl/ssl_locl.h

@@ -843,6 +843,9 @@ struct ssl_ctx_st {
     /* Up to how many pipelines should we use? If 0 then 1 is assumed */
     unsigned int max_pipelines;
 
+    /* The default read buffer length to use (0 means not set) */
+    size_t default_read_buf_len;
+
 #  ifndef OPENSSL_NO_ENGINE
     /*
      * Engine to pass requests for client certs to

util/libssl.num

@@ -381,3 +381,5 @@ SSL_get_ct_validation_callback          380	1_1_0	EXIST::FUNCTION:CT
 SSL_get0_peer_scts                      381	1_1_0	EXIST::FUNCTION:CT
 SSL_CTX_set_ct_validation_callback      382	1_1_0	EXIST::FUNCTION:CT
 SSL_CTX_get_ct_validation_callback      383	1_1_0	EXIST::FUNCTION:CT
+SSL_set_default_read_buffer_len         384	1_1_0	EXIST::FUNCTION:
+SSL_CTX_set_default_read_buffer_len     385	1_1_0	EXIST::FUNCTION: