Support non-default Max-Forward headers for B2BUA (#4473)

Author: wosrediinanatour

pjsip/include/pjsip/print_util.h

@@ -19,6 +19,9 @@
 #ifndef __PJSIP_PRINT_H__
 #define __PJSIP_PRINT_H__
 
+PJ_BEGIN_DECL
+
+
 #define copy_advance_char_check(buf,chr)   \
         do { \
             if (1 >= (endbuf-buf)) return -1;   \
@@ -162,5 +165,8 @@ PJ_INLINE(void) init_hdr(void *hptr, pjsip_hdr_e htype, void *vptr)
     pj_list_init(hdr);
 }
 
+
+PJ_END_DECL
+
 #endif  /* __PJSIP_PRINT_H__ */
 

pjsip/include/pjsua-lib/pjsua.h

@@ -2670,6 +2670,9 @@ struct pjsua_msg_data
      * headers to the list by creating the header, either from the heap/pool
      * or from temporary local variable, and add the header using
      * linked list operation. See pjsua_app.c for some sample codes.
+     *
+     * Application may override Max-Forwards header value (the default is
+     * #PJSIP_MAX_FORWARDS_VALUE) by adding a Max-Forwards header here.
      */
     pjsip_hdr   hdr_list;
 

pjsip/include/pjsua2/siptypes.hpp

@@ -998,6 +998,9 @@ struct SipTxOption
 
     /**
      * Additional message headers to be included in the outgoing message.
+     *
+     * Application may override Max-Forwards header value (the default is
+     * #PJSIP_MAX_FORWARDS_VALUE) by adding a Max-Forwards header here.
      */
     SipHeaderVector         headers;
 

pjsip/src/pjsua-lib/pjsua_core.c

@@ -3165,6 +3165,29 @@ void pjsua_process_msg_data(pjsip_tx_data *tdata,
     while (hdr && hdr != &msg_data->hdr_list) {
         pjsip_hdr *new_hdr;
 
+        /* For Max-Forwards header, just update the value of the existing
+         * header. In case it does not exist, clone the header as usual.
+         */
+        if (hdr->type == PJSIP_H_MAX_FORWARDS) {
+            pjsip_max_fwd_hdr *orig_hdr;
+
+            orig_hdr = pjsip_hdr_find(&tdata->msg->hdr, PJSIP_H_MAX_FORWARDS,
+                                      NULL);
+            if (orig_hdr != NULL) {
+                pj_uint32_t orig_value = orig_hdr->ivalue;
+                pj_uint32_t new_value  =
+                                    ((const pjsip_max_fwd_hdr*)hdr)->ivalue;
+
+                orig_hdr->ivalue = new_value;
+                PJ_LOG(4, (THIS_FILE,
+                           "Overriding Max-Forwards header value: %u -> %u",
+                           orig_value, new_value));
+
+                hdr = hdr->next;
+                continue;
+            }
+        }
+
         new_hdr = (pjsip_hdr*) pjsip_hdr_clone(tdata->pool, hdr);
         pjsip_msg_add_hdr(tdata->msg, new_hdr);
 

pjsip/src/pjsua2/siptypes.cpp

@@ -17,6 +17,7 @@
  */
 #include <pjsua2/types.hpp>
 #include <pjsua2/siptypes.hpp>
+#include <pjsip/print_util.h>       /* For pjsip_hdr_names */
 #include "util.hpp"
 
 using namespace pj;
@@ -788,6 +789,24 @@ void SipTxOption::toPj(pjsua_msg_data &msg_data) const
     pj_list_init(&msg_data.hdr_list);
     for (i = 0; i < headers.size(); i++) {
         pjsip_generic_string_hdr& pj_hdr = headers[i].toPj();
+        
+        /* If the header is Max-Forwards, the header type needs to be
+         * PJSIP_H_MAX_FORWARDS as PJSUA will compare the header type
+         * instead of the string name.
+         */
+        if ((headers[i].hName.size() ==
+             pjsip_hdr_names[PJSIP_H_MAX_FORWARDS].name_len) &&
+            (pj_ansi_strnicmp(headers[i].hName.c_str(),
+                              pjsip_hdr_names[PJSIP_H_MAX_FORWARDS].name,
+                              headers[i].hName.size()) == 0))
+        {
+            pjsip_max_fwd_hdr *tmp = (pjsip_max_fwd_hdr*)&pj_hdr;
+
+            pj_assert(sizeof(pjsip_generic_string_hdr) >=
+                      sizeof(pjsip_max_fwd_hdr));
+            pjsip_max_fwd_hdr_init(NULL, tmp, std::stoi(headers[i].hValue));
+        }
+
         pj_list_push_back(&msg_data.hdr_list, &pj_hdr);
     }