Negotiate protocol version between server and client. Will allow smoother

protocol modifications in the future.


git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@621 fefdeb5f-60dc-0310-8127-8f9354f1896f

configure.ac

@@ -29,6 +29,7 @@ AC_SUBST(PA_MAJORMINOR, "$PACKAGE_VERSION")
 AC_SUBST(PACKAGE_URL, [http://0pointer.de/lennart/projects/polypaudio/])
 
 AC_SUBST(PA_API_VERSION, 8)
+AC_SUBST(PA_PROTOCOL_VERSION, 8)
 
 if type -p stow > /dev/null && test -d /usr/local/stow ; then
    AC_MSG_NOTICE([*** Found /usr/local/stow: default install prefix set to /usr/local/stow/${PACKAGE_NAME}-${PACKAGE_VERSION} ***])

src/polyp/context.c

@@ -354,6 +354,19 @@ static void setup_complete_callback(pa_pdispatch *pd, uint32_t command, uint32_t
     switch(c->state) {
         case PA_CONTEXT_AUTHORIZING: {
             pa_tagstruct *reply;
+
+            if (pa_tagstruct_getu32(t, &c->version) < 0 ||
+                !pa_tagstruct_eof(t)) {
+                pa_context_fail(c, PA_ERR_PROTOCOL);
+                goto finish;
+            }
+
+            /* Minimum supported version */
+            if (c->version < 8) {
+                pa_context_fail(c, PA_ERR_VERSION);
+                goto finish;
+            }
+
             reply = pa_tagstruct_command(c, PA_COMMAND_SET_CLIENT_NAME, &tag);
             pa_tagstruct_puts(reply, c->name);
             pa_pstream_send_tagstruct(c->pstream, reply);
@@ -400,6 +413,7 @@ static void setup_context(pa_context *c, pa_iochannel *io) {
     }
 
     t = pa_tagstruct_command(c, PA_COMMAND_AUTH, &tag);
+    pa_tagstruct_putu32(t, PA_PROTOCOL_VERSION);
     pa_tagstruct_put_arbitrary(t, c->conf->cookie, sizeof(c->conf->cookie));
     pa_pstream_send_tagstruct_with_creds(c->pstream, t, 1);
     pa_pdispatch_register_reply(c->pdispatch, tag, DEFAULT_TIMEOUT, setup_complete_callback, c);
@@ -936,6 +950,17 @@ const char* pa_context_get_server(pa_context *c) {
     return c->server;
 }
 
+uint32_t pa_context_get_protocol_version(pa_context *c) {
+    return PA_PROTOCOL_VERSION;
+}
+
+uint32_t pa_context_get_server_protocol_version(pa_context *c) {
+    assert(c);
+    assert(c->ref >= 1);
+
+    return c->version;
+}
+
 pa_tagstruct *pa_tagstruct_command(pa_context *c, uint32_t command, uint32_t *tag) {
     pa_tagstruct *t;
 

src/polyp/context.h

@@ -115,6 +115,12 @@ pa_operation* pa_context_set_name(pa_context *c, const char *name, pa_context_su
 /** Return the server name this context is connected to. \since 0.7 */
 const char* pa_context_get_server(pa_context *c);
 
+/** Return the protocol version of the library. \since 0.8 */
+uint32_t pa_context_get_protocol_version(pa_context *c);
+
+/** Return the protocol version of the connected server. \since 0.8 */
+uint32_t pa_context_get_server_protocol_version(pa_context *c);
+
 PA_C_DECL_END
 
 #endif

src/polyp/def.h

@@ -125,6 +125,7 @@ enum {
     PA_ERR_MODINITFAILED,          /**< Module initialization failed */
     PA_ERR_BADSTATE,               /**< Bad state */
     PA_ERR_NODATA,                 /**< No data */ 
+    PA_ERR_VERSION,                /**< Incompatible protocol version \since 0.8 */
     PA_ERR_MAX                     /**< Not really an error but the first invalid error code */
 };
 

src/polyp/error.c

@@ -48,6 +48,7 @@ static const char* const errortab[PA_ERR_MAX] = {
     [PA_ERR_MODINITFAILED] = "Module initalization failed",
     [PA_ERR_BADSTATE] = "Bad state",
     [PA_ERR_NODATA] = "No data",
+    [PA_ERR_VERSION] = "Incompatible protocol version",
 };
 
 const char*pa_strerror(int error) {

src/polyp/internal.h

@@ -57,6 +57,7 @@ struct pa_context {
     PA_LLIST_HEAD(pa_stream, streams);
     PA_LLIST_HEAD(pa_operation, operations);
 
+    uint32_t version;
     uint32_t ctag;
     uint32_t csyncid;
     uint32_t error;

src/polyp/version.h.in

@@ -44,6 +44,10 @@ const char* pa_get_library_version(void);
  * PA_API_VERSION undefined.  */
 #define PA_API_VERSION @PA_API_VERSION@
 
+/** The current protocol version. Version 8 relates to polypaudio 0.8.
+ * \since 0.8 */
+#define PA_PROTOCOL_VERSION @PA_PROTOCOL_VERSION@
+
 PA_C_DECL_END
 
 #endif

src/polypcore/protocol-native.c

@@ -29,6 +29,8 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <polyp/version.h>
+
 #include <polypcore/native-common.h>
 #include <polypcore/packet.h>
 #include <polypcore/client.h>
@@ -111,6 +113,7 @@ enum {
 
 struct connection {
     int authorized;
+    uint32_t version;
     pa_protocol_native *protocol;
     pa_client *client;
     pa_pstream *pstream;
@@ -866,14 +869,22 @@ static void command_exit(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t
 static void command_auth(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
     struct connection *c = userdata;
     const void*cookie;
+    pa_tagstruct *reply;
     assert(c && t);
 
-    if (pa_tagstruct_get_arbitrary(t, &cookie, PA_NATIVE_COOKIE_LENGTH) < 0 ||
+    if (pa_tagstruct_getu32(t, &c->version) < 0 ||
+        pa_tagstruct_get_arbitrary(t, &cookie, PA_NATIVE_COOKIE_LENGTH) < 0 ||
         !pa_tagstruct_eof(t)) {
         protocol_error(c);
         return;
     }
 
+    /* Minimum supported version */
+    if (c->version < 8) {
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_VERSION);
+        return;
+    }
+
     if (!c->authorized) {
         int success = 0;
         
@@ -915,8 +926,10 @@ static void command_auth(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t
             c->auth_timeout_event = NULL;
         }
     }
-    
-    pa_pstream_send_simple_ack(c->pstream, tag);
+
+    reply = reply_new(tag);
+    pa_tagstruct_putu32(reply, PA_PROTOCOL_VERSION);
+    pa_pstream_send_tagstruct(c->pstream, reply);
 }
 
 static void command_set_client_name(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {