Add libpq connection option to disable SSL compression

This can be used to remove the overhead of SSL compression on
fast networks.

Laurenz Albe

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 3d5f98ba2a663d5bbf2e8f9cdb1e25e6b9e3edfc..252ff8cc855f68d1041ea94695101dfee992b422 100644 (file)
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -494,6 +494,28 @@ PGconn *PQconnectdbParams(const char * const *keywords,
          </listitem>
         </varlistentry>
 
+        <varlistentry id="libpq-connect-sslcompression" xreflabel="sslcompression">
+         <term><literal>sslcompression</literal></term>
+         <listitem>
+          <para>
+           If set to 1 (default), data sent over SSL connections will be
+           compressed (this requires <productname>OpenSSL</> version
+           0.9.8 or later).
+           If set to 0, compression will be disabled (this requires
+           <productname>OpenSSL</> 1.0.0 or later).
+           This parameter is ignored if a connection without SSL is made,
+           or if the version of <productname>OpenSSL</> used does not support
+           it.
+          </para>
+          <para>
+           Compression uses CPU time, but can improve throughput if
+           the network is the bottleneck.
+           Disabling compression can improve response time and throughput
+           if CPU performance is the limiting factor.
+          </para>
+         </listitem>
+        </varlistentry>
+
         <varlistentry id="libpq-connect-sslcert" xreflabel="sslcert">
          <term><literal>sslcert</literal></term>
          <listitem>
@@ -6308,6 +6330,16 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
      </para>
     </listitem>
 
+    <listitem>
+     <para>
+      <indexterm>
+       <primary><envar>PGSSLCOMPRESSION</envar></primary>
+      </indexterm>
+      <envar>PGSSLCOMPRESSION</envar> behaves the same as the <xref
+      linkend="libpq-connect-sslcompression"> connection parameter.
+     </para>
+    </listitem>
+
     <listitem>
      <para>
       <indexterm>

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index ed9dce941e1d57cce51f2c21bf29769dfe2ee542..50f3f83aaebff31e39b641614ae4ba2b3f9c7a46 100644 (file)
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -222,6 +222,9 @@ static const PQconninfoOption PQconninfoOptions[] = {
        {"sslmode", "PGSSLMODE", DefaultSSLMode, NULL,
        "SSL-Mode", "", 8},                     /* sizeof("disable") == 8 */
 
+       {"sslcompression", "PGSSLCOMPRESSION", "1", NULL,
+       "SSL-Compression", "", 1},
+
        {"sslcert", "PGSSLCERT", NULL, NULL,
        "SSL-Client-Cert", "", 64},
 
@@ -621,6 +624,8 @@ fillPGconn(PGconn *conn, PQconninfoOption *connOptions)
        conn->keepalives_count = tmp ? strdup(tmp) : NULL;
        tmp = conninfo_getval(connOptions, "sslmode");
        conn->sslmode = tmp ? strdup(tmp) : NULL;
+       tmp = conninfo_getval(connOptions, "sslcompression");
+       conn->sslcompression = tmp ? strdup(tmp) : NULL;
        tmp = conninfo_getval(connOptions, "sslkey");
        conn->sslkey = tmp ? strdup(tmp) : NULL;
        tmp = conninfo_getval(connOptions, "sslcert");

diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index 9c6ced6a8280130aaac2b680691430fd92490953..c6963bed9480f9fb61afc70c6e91b7583f9e0bfb 100644 (file)
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -1292,6 +1292,16 @@ initialize_SSL(PGconn *conn)
                }
        }
 
+       /*
+        * If the OpenSSL version used supports it (from 1.0.0 on)
+        * and the user requested it, disable SSL compression.
+        */
+#ifdef SSL_OP_NO_COMPRESSION
+       if (conn->sslcompression && conn->sslcompression[0] == '0') {
+               SSL_set_options(conn->ssl, SSL_OP_NO_COMPRESSION);
+       }
+#endif
+
        return 0;
 }
 

diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index d56ef5d489b5f9964fe4a335ac2de501a2ffd224..64dfcb27fb1b79496cd3ed134c406298587b4f59 100644 (file)
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -310,6 +310,7 @@ struct pg_conn
        char       *keepalives_count;           /* maximum number of TCP keepalive
                                                                                 * retransmits */
        char       *sslmode;            /* SSL mode (require,prefer,allow,disable) */
+       char       *sslcompression;     /* SSL compression (0 or 1) */
        char       *sslkey;                     /* client key filename */
        char       *sslcert;            /* client certificate filename */
        char       *sslrootcert;        /* root certificate filename */