proxy-server bugfix and ui change, doc update

Signed-off-by: Laurent Bercot <ska@appnovation.com>

2 files changed, 40 insertions, 17 deletions

diff --git a/doc/proxy-server.html b/doc/proxy-server.html
index 8363b86..8fb7909 100644
--- a/doc/proxy-server.html
+++ b/doc/proxy-server.html
@@ -36,7 +36,7 @@ for a direct connection.
 <h2> Interface </h2>
 
 <pre>
-     proxy-server [ -1 | -2 ] [ -t <em>timeout</em> ] [ -v <em>verbosity</em> ] <em>prog...</em>
+     proxy-server [ -1||--disable-v2 | -2|--disable-v1 ] [ -t <em>timeout</em> ] [ -v <em>verbosity</em> ] <em>prog...</em>
 </pre>
 
 <ul>
@@ -74,16 +74,18 @@ forever for data. </dd>
  <dt> -v <em>verbosity</em> </dt>
   <dd> Be more or less verbose. The default is 1. Changing it does not
 have much effect at the moment, leave it alone. </dd>
- <dt> -1 </dt>
-  <dd> Expect version 1 of the PROXY protocol: a line of text. </dd>
- <dt> -2 </dt>
-  <dd> Expect version 2 of the PROXY protocol: a binary structure. </dd>
+ <dt> -1 or --disable-v2 </dt>
+  <dd> Disable version 2 of the PROXY protocol, only expect v1, i.e. a line of text. </dd>
+ <dt> -2 or --disable-v1 </dt>
+  <dd> Disable version 1 of the PROXY protocol, only expect v2, i.e. a binary structure. </dd>
 </dl>
 
 <p>
  If neither <tt>-1</tt> or <tt>-2</tt> is selected, proxy-server will default
-to expecting version 2. If you pass both options, proxy-server will support
-both versions of the protocol.
+to supporting both versions of the protocol, at a tiny speed cost. If you pass
+both options, meaning you disable both versions, proxy-server will write a
+warning and directly exec into <em>prog...</em> without expecting a PROXY
+header of any kind.
 </p>
 
 <h2> Common usage </h2>
@@ -137,5 +139,27 @@ the proxy, proxy-server may modify the following variables:
  <li> SSL_TLS_SNI_SERVERNAME </li>
 </ul>
 
+<h2> Notes </h2>
+
+<ul>
+ <li> proxy-server operates by writing UCSPI variables such as <tt>TCPREMOTEIP</tt>.
+These variables are normally set by programs dealing with the TCP connection such as
+<a href="s6-tcpserver.html">s6-tcpserver</a> or
+<a href="s6-tcpserver-access.html">s6-tcpserver-access</a>. To take effect, it needs
+to run <em>after</em> these programs, to override the TCP-provided values with the
+proxy-provided values. </li>
+ <li> When used on a <a href="s6-tlsserver.html">s6-tlsserver</a>, command line,
+proxy-server runs <em>after</em> the TLS connection has been established, i.e. it
+expects the proxy header to be sent in the TLS tunnel. </li>
+ <li> If this is not the case and the proxy header is sent before the TLS connection
+is established, 1. it is probably an insecure setup (if you have a good reason to
+set up a TLS tunnel between your proxy and your server, then the PROXY information
+is worth protecting just as much as the rest of the data), 2. proxy-server needs
+to be run between <a href="s6-tcpserver.html">s6-tcpserver</a> and
+<a href="s6-tlsd.html">s6-tlsd</a>, which you can do by using the (TBD) option
+to <a href="s6-tlsserver.html">s6-tlsserver</a> rather than explicitly calling
+proxy-server on the command line. </li>
+</ul>
+
 </body>
 </html>
diff --git a/src/conn-tools/proxy-server.c b/src/conn-tools/proxy-server.c
index e5c5820..7aab748 100644
--- a/src/conn-tools/proxy-server.c
+++ b/src/conn-tools/proxy-server.c
@@ -19,7 +19,7 @@
 #include <skalibs/unix-timed.h>
 
 #define NAME "proxy-server"
-#define USAGE NAME "[ -1 | -2 ] [ -v verbosity ] [ -t timeout ] prog..."
+#define USAGE NAME "[ --disable-v1 | --disable-v2 ] [ -v verbosity ] [ -t timeout ] prog..."
 #define dieusage() strerr_dieusage(100, USAGE)
 #define dienomem() strerr_diefu1sys(111, "stralloc_catb")
 
@@ -317,10 +317,8 @@ int main (int argc, char const *const *argv)
 {
   static gol_bool const main_golb[4] =
   {
-    { .so = '1', .lo = "enable-v1", .set = 1, .mask = 1 << MAIN_GOLB_V1 },
-    { .so = '2', .lo = "enable-v2", .set = 1, .mask = 1 << MAIN_GOLB_V2 },
-    { .so = 0,  .lo = "disable-v1", .set = 0, .mask = 1 << MAIN_GOLB_V1 },
-    { .so = 0,  .lo = "disable-v2", .set = 0, .mask = 1 << MAIN_GOLB_V2 }
+    { .so = '1', .lo = "disable-v2", .set = 0, .mask = 1 << MAIN_GOLB_V2 },
+    { .so = '2', .lo = "disable-v1", .set = 0, .mask = 1 << MAIN_GOLB_V1 },
   } ;
   static gol_arg const main_gola[MAIN_GOLA_N] =
   {
@@ -328,7 +326,7 @@ int main (int argc, char const *const *argv)
     { .so = 'v', .lo = "verbosity", .i = MAIN_GOLA_VERBOSITY }
   } ;
 
-  uint64_t golb = 0 ;
+  uint64_t golb = 1 << MAIN_GOLB_V1 | 1 << MAIN_GOLB_V2 ;
   PROG = NAME ;
 
   {
@@ -352,9 +350,10 @@ int main (int argc, char const *const *argv)
   PROG_pid_fill(prog_storage, NAME) ;
   PROG = prog_storage ;
 
-  if ((golb & (1 << MAIN_GOLB_V1 | 1 << MAIN_GOLB_V2)) == 0) golb |= 1 << MAIN_GOLB_V2 ;
-  if ((golb & (1 << MAIN_GOLB_V1 | 1 << MAIN_GOLB_V2)) == 1 << MAIN_GOLB_V2) v2() ;
-  else if ((golb & (1 << MAIN_GOLB_V1 | 1 << MAIN_GOLB_V2)) == 1 << MAIN_GOLB_V1) v1() ;
-  else both() ;
+  uint64_t ver = golb & (1 << MAIN_GOLB_V1 | 1 << MAIN_GOLB_V2) ;
+  if (ver == (1 << MAIN_GOLB_V1 | 1 << MAIN_GOLB_V2)) both() ;
+  else if (ver == 1 << MAIN_GOLB_V2) v2() ;
+  else if (ver == 1 << MAIN_GOLB_V1) v1() ;
+  else if (verbosity) strerr_warnw1x("both versions disabled, no proxy protocol expected") ;
   xmexec(argv) ;
 }