dialog: added h_id_start and h_id_step parameters

- allow to control how internal dialog hash id is generated to avoid
overalapping values across many instances of kamailio

src/modules/dialog/dialog.c

@@ -63,6 +63,7 @@
 #include "../../core/mem/mem.h"
 #include "../../core/timer_proc.h"
 #include "../../core/lvalue.h"
+#include "../../core/globals.h"
 #include "../../core/parser/parse_to.h"
 #include "../../modules/tm/tm_load.h"
 #include "../../core/rpc_lookup.h"
@@ -124,6 +125,9 @@ str ruri_pvar_param = str_init("$ru");
 pv_elem_t * ruri_param_model = NULL;
 str empty_str = STR_NULL;
 
+int dlg_h_id_start = 0;
+int dlg_h_id_step = 1;
+
 /* statistic variables */
 int dlg_enable_stats = 1;
 int active_dlgs_cnt = 0;
@@ -315,6 +319,8 @@ static param_export_t mod_params[]={
 	{ "early_timeout",         PARAM_INT, &dlg_early_timeout        },
 	{ "noack_timeout",         PARAM_INT, &dlg_noack_timeout        },
 	{ "end_timeout",           PARAM_INT, &dlg_end_timeout          },
+	{ "h_id_start",            PARAM_INT, &dlg_h_id_start           },
+	{ "h_id_step",             PARAM_INT, &dlg_h_id_step            },
 	{ 0,0,0 }
 };
 
@@ -470,6 +476,16 @@ static int mod_init(void)
 	unsigned int n;
 	sr_cfgenv_t *cenv = NULL;
 
+	if(dlg_h_id_start==-1) {
+		dlg_h_id_start = server_id;
+	} else if(dlg_h_id_start<0) {
+		dlg_h_id_start = 0;
+	}
+
+	if(dlg_h_id_step<1) {
+		dlg_h_id_step = 1;
+	}
+
 	if(dlg_ka_interval!=0 && dlg_ka_interval<30) {
 		LM_ERR("ka interval too low (%d), has to be at least 30\n",
 				dlg_ka_interval);

src/modules/dialog/dlg_db_handler.c

@@ -82,7 +82,8 @@ static db_func_t dialog_dbf;
 extern int dlg_enable_stats;
 extern int active_dlgs_cnt;
 extern int early_dlgs_cnt;
-
+extern int dlg_h_id_start;
+extern int dlg_h_id_step;
 
 #define SET_STR_VALUE(_val, _str)\
 	do{\
@@ -281,6 +282,7 @@ int load_dialog_info_from_db(int dlg_hash_size, int fetch_num_rows,
 	dlg_iuid_t dbuid[DLG_MAX_DB_LOAD_EXTRA];
 	int loaded_extra = 0;
 	int loaded_extra_more = 0;
+	dlg_cell_t *dit;
 
 	if(use_dialog_table() != 0){
 		return -1;
@@ -363,17 +365,39 @@ int load_dialog_info_from_db(int dlg_hash_size, int fetch_num_rows,
 
 			if(mode!=0) {
 				dlg_lock(d_table, &(d_table->entries[dlg->h_entry]));
+				/* loading at runtime - check dialog id conflicts */
+				dit = (d_table->entries)[dlg->h_entry].first;
+				while (dit) {
+					if (dit->h_id == VAL_INT(values+1)) {
+						break;
+					}
+					dit = dit->next;
+				}
+				if(dit) {
+					LM_WARN("conflicting dialog id: %u/%u - skipping\n",
+							dlg->h_entry, (unsigned int)VAL_INT(values+1));
+					dlg_unlock(d_table, &(d_table->entries[dlg->h_entry]));
+					shm_free(dlg);
+					continue;
+				}
 			}
 
 			/*link the dialog*/
 			link_dlg(dlg, 0, 0);
 
 			dlg->h_id = VAL_INT(values+1);
 			next_id = d_table->entries[dlg->h_entry].next_id;
-
-			d_table->entries[dlg->h_entry].next_id =
-				(next_id <= dlg->h_id) ? (dlg->h_id+1) : next_id;
-
+			if(dlg_h_id_step==1) {
+				d_table->entries[dlg->h_entry].next_id =
+						(next_id <= dlg->h_id) ? (dlg->h_id+1) : next_id;
+			} else {
+				/* update next id only if matches this instance series */
+				if((dlg->h_id - dlg_h_id_start) % dlg_h_id_step == 0) {
+					d_table->entries[dlg->h_entry].next_id =
+						(next_id <= dlg->h_id) ? (dlg->h_id + dlg_h_id_step)
+								: next_id;
+				}
+			}
 			if(mode!=0) {
 				dlg_unlock(d_table, &(d_table->entries[dlg->h_entry]));
 			}

src/modules/dialog/dlg_hash.c

@@ -51,6 +51,8 @@ extern int dlg_enable_dmq;
 extern int dlg_early_timeout;
 extern int dlg_noack_timeout;
 extern int dlg_end_timeout;
+extern int dlg_h_id_start;
+extern int dlg_h_id_step;
 
 /*! global dialog table */
 struct dlg_table *d_table = 0;
@@ -308,7 +310,12 @@ int init_dlg_table(unsigned int size)
 			LM_ERR("failed to init lock for slot: %d\n", i);
 			goto error1;
 		}
-		d_table->entries[i].next_id = kam_rand() % (3*size);
+		if(dlg_h_id_step>1) {
+			d_table->entries[i].next_id = dlg_h_id_start
+					+ (dlg_h_id_step * ((kam_rand() % (3*size)) + 1));
+		} else {
+			d_table->entries[i].next_id = kam_rand() % (3*size);
+		}
 	}
 
 	return 0;
@@ -884,8 +891,17 @@ void link_dlg(struct dlg_cell *dlg, int n, int mode)
 	if(unlikely(mode==0)) dlg_lock( d_table, d_entry);
 
 	/* keep id 0 for special cases */
-	dlg->h_id = 1 + d_entry->next_id++;
-	if(dlg->h_id == 0) dlg->h_id = 1;
+	if(dlg_h_id_step>1) {
+		if((d_entry->next_id==0)
+				|| (d_entry->next_id + dlg_h_id_step < d_entry->next_id)) {
+			d_entry->next_id = dlg_h_id_start + dlg_h_id_step;
+		}
+		dlg->h_id = d_entry->next_id;
+		d_entry->next_id += dlg_h_id_step;
+	} else {
+		dlg->h_id = 1 + d_entry->next_id++;
+		if(dlg->h_id == 0) dlg->h_id = 1;
+	}
 	LM_DBG("linking dialog [%u:%u]\n", dlg->h_entry, dlg->h_id);
 	if (d_entry->first==0) {
 		d_entry->first = d_entry->last = dlg;