From e0088298ef140eed031bbdbc0cbc5feebf8e2976 Mon Sep 17 00:00:00 2001
From: Bruce Guenter <bruce@untroubled.org>
Date: Sun, 12 Nov 2006 20:42:40 +0000
Subject: [PATCH] Added a version number to the plugin ABI to prevent semantic
 mismatches.

---
 NEWS                    | 4 ++--
 backend-echo.c          | 1 +
 backend-qmail.c         | 1 +
 mailfront.h             | 6 ++++++
 modules.c               | 9 +++++++++
 plugin-add-received.c   | 1 +
 plugin-check-fqdn.c     | 1 +
 plugin-clamav.c         | 1 +
 plugin-counters.c       | 1 +
 plugin-cvm-validate.c   | 1 +
 plugin-mailrules.c      | 1 +
 plugin-patterns.c       | 1 +
 plugin-qmail-validate.c | 1 +
 plugin-reject.c         | 1 +
 plugin-relayclient.c    | 1 +
 plugin-require-auth.c   | 1 +
 plugin.c                | 1 +
 protocol-qmqp.c         | 1 +
 protocol-qmtp.c         | 1 +
 protocol-smtp.c         | 1 +
 20 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index d40b3fb..e88cbe3 100644
--- a/NEWS
+++ b/NEWS
@@ -3,8 +3,8 @@ Changes in version 1.10
 
 - Added a ClamAV virus scanner plugin.
 
-- Modified the plugin API to add a flags word and to (optionally) save
-  messages to a temporary file (needed by the ClamAV plugin).
+- Modified the plugin API to add a version code, a flags word, and to
+  (optionally) save messages to a temporary file.
 
 Development of this version has been sponsored by FutureQuest, Inc.
 ossi@FutureQuest.net  http://www.FutureQuest.net/
diff --git a/backend-echo.c b/backend-echo.c
index e530018..81d55b3 100644
--- a/backend-echo.c
+++ b/backend-echo.c
@@ -85,6 +85,7 @@ static const response* message_end(int fd)
 }
 
 struct plugin backend = {
+  .version = PLUGIN_VERSION,
   .reset = reset,
   .sender = sender,
   .recipient = recipient,
diff --git a/backend-qmail.c b/backend-qmail.c
index 391f018..d659464 100644
--- a/backend-qmail.c
+++ b/backend-qmail.c
@@ -204,6 +204,7 @@ static const response* message_end(int fd)
 }
 
 struct plugin backend = {
+  .version = PLUGIN_VERSION,
   .reset = reset,
   .sender = do_sender,
   .recipient = do_recipient,
diff --git a/mailfront.h b/mailfront.h
index 0d8f031..5e463ab 100644
--- a/mailfront.h
+++ b/mailfront.h
@@ -9,8 +9,11 @@
 
 #define FLAG_NEED_FILE (1<<0)
 
+#define PLUGIN_VERSION 2
+
 struct plugin
 {
+  unsigned version;
   struct plugin* next;
   const char* name;
   unsigned flags;
@@ -24,8 +27,11 @@ struct plugin
   const response* (*message_end)(int fd);
 };
 
+#define PROTOCOL_VERSION 2
+
 struct protocol
 {
+  unsigned version;
   const char* name;
   int (*respond_line)(unsigned number, int final,
 		      const char* msg, unsigned long len);
diff --git a/modules.c b/modules.c
index 1b6fefb..e259bec 100644
--- a/modules.c
+++ b/modules.c
@@ -6,6 +6,9 @@
 #include "conf_modules.c"
 
 static response resp_load = { 451, 0 };
+static RESPONSE(backend_version,451,"4.3.0 Backend ABI version mismatch");
+static RESPONSE(plugin_version,451,"4.3.0 Plugin ABI version mismatch");
+static RESPONSE(protocol_version,451,"4.3.0 Protocol ABI version mismatch");
 
 struct plugin* plugin_list = 0;
 struct plugin* plugin_tail = 0;
@@ -97,6 +100,8 @@ static const response* load_plugin(const char* name)
     if ((plugin = find_builtin_plugin(name)) == 0) {
       if ((plugin = load_object("plugin", name)) == 0)
 	return &resp_load;
+      if (plugin->version != PLUGIN_VERSION)
+	return &resp_plugin_version;
       if ((plugin->name = strdup(name)) == 0)
 	return &resp_oom;
     }
@@ -140,8 +145,12 @@ const response* load_modules(const char* protocol_name,
     module_path = conf_modules;
   if ((session.protocol = load_object("protocol", protocol_name)) == 0)
     return &resp_load;
+  if (session.protocol->version != PROTOCOL_VERSION)
+    return &resp_protocol_version;
   if ((session.backend = load_object("backend", backend_name)) == 0)
     return &resp_load;
+  if (session.backend->version != PLUGIN_VERSION)
+    return &resp_backend_version;
   module_flags |= session.backend->flags;
   while (*plugins != 0)
     if ((r = load_plugins(*plugins++)) != 0)
diff --git a/plugin-add-received.c b/plugin-add-received.c
index a727b91..6a38966 100644
--- a/plugin-add-received.c
+++ b/plugin-add-received.c
@@ -144,6 +144,7 @@ static const response* data_start(int fd)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .init = init,
   .data_start = data_start,
 };
diff --git a/plugin-check-fqdn.c b/plugin-check-fqdn.c
index 3f09c2d..f84c25e 100644
--- a/plugin-check-fqdn.c
+++ b/plugin-check-fqdn.c
@@ -17,6 +17,7 @@ static const response* either(str* s)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .sender = either,
   .recipient = either,
 };
diff --git a/plugin-clamav.c b/plugin-clamav.c
index 0020462..8ada986 100644
--- a/plugin-clamav.c
+++ b/plugin-clamav.c
@@ -102,6 +102,7 @@ static const response* message_end(int fd)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .flags = FLAG_NEED_FILE,
   .message_end = message_end,
 };
diff --git a/plugin-counters.c b/plugin-counters.c
index 633f780..eec3f5a 100644
--- a/plugin-counters.c
+++ b/plugin-counters.c
@@ -126,6 +126,7 @@ static const response* block(const char* bytes, unsigned long len)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .init = init,
   .reset = reset,
   .sender = sender,
diff --git a/plugin-cvm-validate.c b/plugin-cvm-validate.c
index 8bb178b..764efc1 100644
--- a/plugin-cvm-validate.c
+++ b/plugin-cvm-validate.c
@@ -53,6 +53,7 @@ static const response* validate_recipient(str* recipient)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .init = validate_init,
   .recipient = validate_recipient,
 };
diff --git a/plugin-mailrules.c b/plugin-mailrules.c
index b3c0435..f214cad 100644
--- a/plugin-mailrules.c
+++ b/plugin-mailrules.c
@@ -426,6 +426,7 @@ static const response* validate_recipient(str* recipient)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .init = init,
   .reset = reset,
   .sender = validate_sender,
diff --git a/plugin-patterns.c b/plugin-patterns.c
index 368e94f..a2d1b8d 100644
--- a/plugin-patterns.c
+++ b/plugin-patterns.c
@@ -149,6 +149,7 @@ static const response* check(const char* bytes, unsigned long len)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .data_start = init,
   .data_block = check,
 };
diff --git a/plugin-qmail-validate.c b/plugin-qmail-validate.c
index 241dbfb..e94a351 100644
--- a/plugin-qmail-validate.c
+++ b/plugin-qmail-validate.c
@@ -87,6 +87,7 @@ static const response* validate_recipient(str* recipient)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .init = validate_init,
   .sender = validate_sender,
   .recipient = validate_recipient,
diff --git a/plugin-reject.c b/plugin-reject.c
index bde563e..d269b37 100644
--- a/plugin-reject.c
+++ b/plugin-reject.c
@@ -24,5 +24,6 @@ static const response* sender(str* s)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .sender = sender,
 };
diff --git a/plugin-relayclient.c b/plugin-relayclient.c
index c9f7fb1..ccec5d1 100644
--- a/plugin-relayclient.c
+++ b/plugin-relayclient.c
@@ -16,5 +16,6 @@ static const response* do_recipient(str* recipient)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .recipient = do_recipient,
 };
diff --git a/plugin-require-auth.c b/plugin-require-auth.c
index f97e700..4f2fc5e 100644
--- a/plugin-require-auth.c
+++ b/plugin-require-auth.c
@@ -12,5 +12,6 @@ static const response* sender(str* s)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .sender = sender,
 };
diff --git a/plugin.c b/plugin.c
index f9b0805..05ded4b 100644
--- a/plugin.c
+++ b/plugin.c
@@ -40,6 +40,7 @@ static const response* message_end(int fd)
 }
 
 struct plugin plugin = {
+  .version = PLUGIN_VERSION,
   .flags = 0,
   .init = init,
   .helo = helo,
diff --git a/protocol-qmqp.c b/protocol-qmqp.c
index 7d019a4..03f0f71 100644
--- a/protocol-qmqp.c
+++ b/protocol-qmqp.c
@@ -103,6 +103,7 @@ static int mainloop(void)
 }
 
 struct protocol protocol = {
+  .version = PROTOCOL_VERSION,
   .name = "QMQP",
   .respond_line = qmtp_respond_line,
   .mainloop = mainloop,
diff --git a/protocol-qmtp.c b/protocol-qmtp.c
index 511ef2d..f59bfee 100644
--- a/protocol-qmtp.c
+++ b/protocol-qmtp.c
@@ -108,6 +108,7 @@ static int mainloop(void)
 }
 
 struct protocol protocol = {
+  .version = PROTOCOL_VERSION,
   .name = "QMTP",
   .respond_line = qmtp_respond_line,
   .mainloop = mainloop,
diff --git a/protocol-smtp.c b/protocol-smtp.c
index ec2b2ff..eaa9b89 100644
--- a/protocol-smtp.c
+++ b/protocol-smtp.c
@@ -407,6 +407,7 @@ static int smtp_respond_line(unsigned num, int final,
 }
 
 struct protocol protocol = {
+  .version = PROTOCOL_VERSION,
   .name = "SMTP",
   .respond_line = smtp_respond_line,
   .init = init,