Push DialogID into username when doing TH

The new "D" flag of the topology_hiding() function forces the insertion of the dialog ID (DID) into the Contact Username, rather than Contact URI parameters (as before). This work was sponsored by Stella Telecom (https://www.stella-telecom.fr/), thank you for supporting OpenSIPS project ! Closes #1014.
OpenSIPS · Feb 4, 2017 · 1fcb7e5 · 1fcb7e5
1 parent fb0d97d
commit 1fcb7e5
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Showing 6 changed files with 96 additions and 17 deletions.
diff --git a/modules/dialog/dialog.c b/modules/dialog/dialog.c
@@ -1104,6 +1104,8 @@ static int w_match_dialog(struct sip_msg *msg)
 	int backup,i;
 	void *match_param = NULL;
 	struct sip_uri *r_uri;
+	str s;
+	char *p;
 
 
 	/* dialog already found ? */
@@ -1139,7 +1141,29 @@ static int w_match_dialog(struct sip_msg *msg)
 					r_uri->u_val[i].len,r_uri->u_val[i].s);
 				/* pass the param value to the matching funcs */
 				match_param = (void *)(&r_uri->u_val[i]);
+				break;
 			}
+		if (match_param==NULL) {
+			/* looking for ".did.hash.label" in the USERNAME */
+			s = r_uri->user;
+			while( (p=q_memchr(s.s,DLG_SEPARATOR,s.len))!=NULL ) {
+				if ( s.s+s.len-p-1 > rr_param.len+2 ) {
+					if (strncmp( p+1, rr_param.s, rr_param.len)==0 &&
+					p[rr_param.len+1]==DLG_SEPARATOR ) {
+						p += rr_param.len+2;
+						s.len = s.s+s.len-p;
+						s.s = p;
+						match_param = (void*)(&s);
+						break;
+					}
+				}
+				if (p+1<s.s+s.len) {
+					s.len = s.s+s.len-p+1;
+					s.s = p+1;
+				} else
+					break;
+			}
+		}
 	}
 
 sipwise:

diff --git a/modules/dialog/dlg_hash.h b/modules/dialog/dlg_hash.h
@@ -117,6 +117,7 @@ struct dlg_leg {
 #define TOPOH_ONGOING     (1 << 1)
 #define TOPOH_KEEP_USER   (1 << 2)
 #define TOPOH_HIDE_CALLID (1 << 3)
+#define TOPOH_DID_IN_USER (1 << 4)
 
 struct dlg_cell
 {

diff --git a/modules/topology_hiding/README b/modules/topology_hiding/README
@@ -216,6 +216,9 @@ modparam("topology_hiding", "th_contact_encode_param", "customparam")
    Optionally,the function also receives a string parameter, which
    holds string flags. Current options for the string flags are :
      * U - Propagate the Username in the Contact header URI
+     * D - Dialog ID (DID) is pushed into Contact username, rather
+       than URI param. This option makes sense only when using
+       topology hiding with dialog support.
      * C - Encode the callid header
        There are many cases where propagating the callid towards
        the callee side is not a good idea, since sometimes the

diff --git a/modules/topology_hiding/doc/topology_hiding_admin.xml b/modules/topology_hiding/doc/topology_hiding_admin.xml
@@ -228,6 +228,10 @@ modparam("topology_hiding", "th_contact_encode_param", "customparam")
 					<para><emphasis>U</emphasis> - Propagate the Username in the Contact header URI
 					</para>
 				</listitem>
+	<listitem>
+					<para><emphasis>D</emphasis> - Dialog ID (DID) is pushed into Contact username, rather than URI param. This option makes sense only when using topology hiding with dialog support.
+					</para>
+				</listitem>
 				<listitem>
 					<para><emphasis>C</emphasis> - Encode the callid header
 					</para>

diff --git a/modules/topology_hiding/topo_hiding_logic.c b/modules/topology_hiding/topo_hiding_logic.c
@@ -376,15 +376,24 @@ static int topo_dlg_replace_contact(struct sip_msg* msg, struct dlg_cell* dlg)
 			contact = ((contact_body_t *)msg->contact->parsed)->contacts->uri;
 			if(parse_uri(contact.s, contact.len, &ctu) < 0) {
 				LM_ERR("Bad Contact URI\n");
+				if (dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER))
+					prefix_len += RR_DLG_PARAM_SIZE + 1;
 			} else {
 				ct_username = ctu.user.s;
 				ct_username_len = ctu.user.len;
 				LM_DBG("Trying to propagate username [%.*s]\n",ct_username_len,
 									ct_username);
-				if (ct_username_len > 0)
+				if (ct_username_len > 0) {
 					prefix_len += 1 + /* @ */ + ct_username_len;
+					if (dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER))
+						prefix_len += RR_DLG_PARAM_SIZE;
+				} else if (dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER)) {
+					prefix_len += RR_DLG_PARAM_SIZE + 1;
+				}
 			}
 		}
+	} else if (dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER)) {
+		prefix_len += RR_DLG_PARAM_SIZE + 1;
 	}
 
 	prefix = pkg_malloc(prefix_len);
@@ -393,7 +402,10 @@ static int topo_dlg_replace_contact(struct sip_msg* msg, struct dlg_cell* dlg)
 		goto error;
 	}
 
-	suffix_len = RR_DLG_PARAM_SIZE+1; /* > */
+	if (dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER))
+		suffix_len = 1; /* > */
+	else
+		suffix_len = RR_DLG_PARAM_SIZE+1; /* > */
 	if (th_param_list) {
 		if ( parse_contact(msg->contact)<0 ||
 			((contact_body_t *)msg->contact->parsed)->contacts==NULL ||
@@ -450,28 +462,59 @@ static int topo_dlg_replace_contact(struct sip_msg* msg, struct dlg_cell* dlg)
 		goto error;
 	}
 
-	memcpy(prefix,"<sip:", 5);
+	rr_param = dlg_api.get_rr_param();
+
+	p = prefix;
+	memcpy( p, "<sip:", 5);
+	p += 5;
 	if (dlg_api.is_mod_flag_set(dlg,TOPOH_KEEP_USER) && ct_username_len > 0) {
-		memcpy(prefix+5,ct_username,ct_username_len);
-		prefix[prefix_len-1] = '@';
+		memcpy( p, ct_username, ct_username_len);
+		p += ct_username_len;
+	}
+	if (dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER)) {
+		if (p==prefix+5)
+			*(p++) = 'X';
+		/* add '.' */
+		*(p++) = DLG_SEPARATOR;
+		/* add "did" */
+		memcpy(p,rr_param->s,rr_param->len);
+		p+=rr_param->len;
+		/* add '.' */
+		*(p++) = DLG_SEPARATOR;
+		/* add hash entry as hexa */
+		n = RR_DLG_PARAM_SIZE - (p-prefix);
+		if (int2reverse_hex( &p, &n, dlg->h_entry)==-1)
+			return -1;
+		/* add '.' */
+		*(p++) = DLG_SEPARATOR;
+		/* add hash entry as hexa */
+		n = RR_DLG_PARAM_SIZE - (p-prefix);
+		if (int2reverse_hex( &p, &n, dlg->h_id)==-1)
+			return -1;
 	}
+	if (p!=prefix+5)
+		*(p++) = '@';
+
+	prefix_len = p - prefix;
 
-	rr_param = dlg_api.get_rr_param();
 	p_init = p = suffix;
-	*p++ = ';';
-	memcpy(p,rr_param->s,rr_param->len);
-	p+=rr_param->len;
-	*p++ = '=';
 
-	n = RR_DLG_PARAM_SIZE - (p-p_init);
-	if (int2reverse_hex( &p, &n, dlg->h_entry)==-1)
-		return -1;
+	if (!dlg_api.is_mod_flag_set(dlg,TOPOH_DID_IN_USER)) {
+		*p++ = ';';
+		memcpy(p,rr_param->s,rr_param->len);
+		p+=rr_param->len;
+		*p++ = '=';
+
+		n = RR_DLG_PARAM_SIZE - (p-p_init);
+		if (int2reverse_hex( &p, &n, dlg->h_entry)==-1)
+			return -1;
 
-	*(p++) = DLG_SEPARATOR;
+		*(p++) = DLG_SEPARATOR;
 
-	n = RR_DLG_PARAM_SIZE - (p-p_init);
-	if (int2reverse_hex( &p, &n, dlg->h_id)==-1)
-		return -1;
+		n = RR_DLG_PARAM_SIZE - (p-p_init);
+		if (int2reverse_hex( &p, &n, dlg->h_id)==-1)
+			return -1;
+	}
 
 	if (th_param_list) {
 		for (el=th_param_list;el;el=el->next) {

diff --git a/modules/topology_hiding/topology_hiding.c b/modules/topology_hiding/topology_hiding.c
@@ -212,6 +212,10 @@ int w_topology_hiding1(struct sip_msg *req,char *param)
 				flags |= TOPOH_HIDE_CALLID;
 				LM_DBG("Will change callid while doing topo hiding\n");
 				break;
+			case 'D':
+				flags |= TOPOH_DID_IN_USER;
+				LM_DBG("Will push DID into contact username\n");
+				break;
 			default:
 				LM_DBG("unknown topology_hiding flag : [%c] . Skipping\n",*p);
 		}