Add a stun_agent_set_software API and correctly append only the first 128 utf-8 characters

4 files changed, 82 insertions, 12 deletions

diff --git a/stun/stun5389.c b/stun/stun5389.c
index fa100fd..32f1c1b 100644
--- a/stun/stun5389.c
+++ b/stun/stun5389.c
@@ -53,6 +53,21 @@
 #include "stuncrc32.h"
 #include "stunmessage.h"
 
+
+static const char utf8_skip_data[256] = {
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1
+};
+
+#define next_utf8_char(p) (char *)((p) + \
+      utf8_skip_data[*(const unsigned char *)(p)])
+
 uint32_t stun_fingerprint (const uint8_t *msg, size_t len,
     bool wlm2009_stupid_crc32_typo)
 {
@@ -81,10 +96,21 @@ bool stun_message_has_cookie (const StunMessage *msg)
 }
 
 
-StunMessageReturn stun_message_append_software (StunMessage *msg)
+StunMessageReturn stun_message_append_software (StunMessage *msg,
+    const char *software)
 {
-  static const char software[] = PACKAGE_STRING;
-  // assert (strlen (software) < 128);
+  int len = 0;
+  const char *ptr = NULL;
+
+  if (software == NULL)
+    software = PACKAGE_STRING;
+
+  ptr = software;
+  while (*ptr && len < 128) {
+    ptr = next_utf8_char (ptr);
+    len++;
+  }
 
-  return stun_message_append_string (msg, STUN_ATTRIBUTE_SOFTWARE, software);
+  return stun_message_append_bytes (msg, STUN_ATTRIBUTE_SOFTWARE, software,
+      ptr - software);
 }
diff --git a/stun/stun5389.h b/stun/stun5389.h
index 3387304..5f3a65e 100644
--- a/stun/stun5389.h
+++ b/stun/stun5389.h
@@ -60,7 +60,8 @@
 uint32_t stun_fingerprint (const uint8_t *msg, size_t len,
     bool wlm2009_stupid_crc32_typo);
 
-StunMessageReturn stun_message_append_software (StunMessage *msg);
+StunMessageReturn stun_message_append_software (StunMessage *msg,
+    const char *software);
 
 
 #endif /* _STUN_5389_H */
diff --git a/stun/stunagent.c b/stun/stunagent.c
index fb8121c..68c81c3 100644
--- a/stun/stunagent.c
+++ b/stun/stunagent.c
@@ -59,6 +59,7 @@ void stun_agent_init (StunAgent *agent, const uint16_t *known_attributes,
   agent->known_attributes = (uint16_t *) known_attributes;
   agent->compatibility = compatibility;
   agent->usage_flags = usage_flags;
+  agent->software_attribute = NULL;
 
   for (i = 0; i < STUN_AGENT_MAX_SAVED_IDS; i++) {
     agent->sent_ids[i].valid = FALSE;
@@ -358,6 +359,12 @@ bool stun_agent_init_request (StunAgent *agent, StunMessage *msg,
       uint32_t cookie = htonl (STUN_MAGIC_COOKIE);
       memcpy (msg->buffer + STUN_MESSAGE_TRANS_ID_POS, &cookie, sizeof (cookie));
     }
+    if (agent->software_attribute != NULL ||
+        ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
+            agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
+            agent->usage_flags & STUN_AGENT_USAGE_ADD_SOFTWARE)) {
+      stun_message_append_software (msg, agent->software_attribute);
+    }
   }
 
   return ret;
@@ -416,10 +423,11 @@ bool stun_agent_init_response (StunAgent *agent, StunMessage *msg,
   if (stun_message_init (msg, STUN_RESPONSE,
           stun_message_get_method (request), id)) {
 
-    if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
+    if (agent->software_attribute != NULL ||
+        ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
             agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
-      agent->usage_flags & STUN_AGENT_USAGE_ADD_SOFTWARE) {
-      stun_message_append_software (msg);
+            agent->usage_flags & STUN_AGENT_USAGE_ADD_SOFTWARE)) {
+      stun_message_append_software (msg, agent->software_attribute);
     }
     return TRUE;
   }
@@ -452,10 +460,11 @@ bool stun_agent_init_error (StunAgent *agent, StunMessage *msg,
   if (stun_message_init (msg, STUN_ERROR,
           stun_message_get_method (request), id)) {
 
-    if ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
+    if (agent->software_attribute != NULL ||
+        ((agent->compatibility == STUN_COMPATIBILITY_RFC5389 ||
             agent->compatibility == STUN_COMPATIBILITY_WLM2009) &&
-      agent->usage_flags & STUN_AGENT_USAGE_ADD_SOFTWARE) {
-      stun_message_append_software (msg);
+            agent->usage_flags & STUN_AGENT_USAGE_ADD_SOFTWARE)) {
+      stun_message_append_software (msg, agent->software_attribute);
     }
     if (stun_message_append_error (msg, err) == STUN_MESSAGE_RETURN_SUCCESS) {
       return TRUE;
@@ -674,3 +683,8 @@ stun_agent_find_unknowns (StunAgent *agent, const StunMessage * msg,
   stun_debug ("STUN unknown: %u mandatory attribute(s)!\n", count);
   return count;
 }
+
+void stun_agent_set_software (StunAgent *agent, char *software)
+{
+  agent->software_attribute = software;
+}
diff --git a/stun/stunagent.h b/stun/stunagent.h
index 6aed2aa..f83837a 100644
--- a/stun/stunagent.h
+++ b/stun/stunagent.h
@@ -138,7 +138,10 @@ typedef enum {
  * @STUN_AGENT_USAGE_USE_FINGERPRINT: The agent should add the FINGERPRINT
  * attribute to the STUN messages it creates.
  * @STUN_AGENT_USAGE_ADD_SOFTWARE: The agent should add the SOFTWARE attribute
- * to the STUN messages it creates
+ * to the STUN messages it creates. Calling nice_agent_set_software() will have
+ * the same effect as enabling this Usage. STUN Indications do not have the
+ * SOFTWARE attributes added to them though. The SOFTWARE attribute is only
+ * added for the RFC5389 and WLM2009 compatibility modes.
  * @STUN_AGENT_USAGE_IGNORE_CREDENTIALS: The agent should ignore any credentials
  * in the STUN messages it receives (the MESSAGE-INTEGRITY attribute
  * will never be validated by stun_agent_validate())
@@ -184,6 +187,7 @@ struct stun_agent_t {
   StunAgentSavedIds sent_ids[STUN_AGENT_MAX_SAVED_IDS];
   uint16_t *known_attributes;
   StunAgentUsageFlags usage_flags;
+  char *software_attribute;
 };
 
 /**
@@ -470,4 +474,29 @@ size_t stun_agent_finish_message (StunAgent *agent, StunMessage *msg,
 bool stun_agent_forget_transaction (StunAgent *agent, StunTransactionId id);
 
 
+/**
+ * stun_agent_set_software:
+ * @agent: The #StunAgent
+ * @software: The value of the SOFTWARE attribute to add.
+ *
+ * This function will set the value of the SOFTWARE attribute to be added to
+ * STUN requests, responses and error responses.
+ * <para>
+ * Calling this function will automatically enable the addition of the SOFTWARE
+ * attribute for RFC5389 and WLM2009 compatibility modes.
+ * </para>
+ * <note>
+     <para>
+       The @software argument must be in UTF-8 encoding and only the first
+       128 characters will be sent.
+     </para>
+     <para>
+       The value of the @software argument must stay valid throughout the life of
+       the StunAgent's life. Do not free its content.
+     </para>
+   </note>
+ *
+ */
+void stun_agent_set_software (StunAgent *agent, char *software);
+
 #endif /* _STUN_AGENT_H */