app_voicemail: Add option to prevent message deletion.

Adds an option to VoiceMailMain that prevents the user
from deleting messages during that application invocation.
This can be useful for public or shared mailboxes, where
some users should be able to listen to messages but not
delete them.

ASTERISK-30063 #close

Change-Id: Icdfb8423ae8d1fce65a056b603eb84a672e80a26

Author: InterLinked1

apps/app_voicemail.c

@@ -219,6 +219,10 @@
 						<para>Use the specified amount of gain when recording a voicemail message.
 						The units are whole-number decibels (dB).</para>
 					</option>
+					<option name="r">
+						<para>"Read only". Prevent user from deleting any messages.</para>
+						<para>This applies only to specific executions of VoiceMailMain, NOT the mailbox itself.</para>
+					</option>
 					<option name="s">
 						<para>Skip checking the passcode for the mailbox.</para>
 					</option>
@@ -592,6 +596,7 @@ enum vm_option_flags {
 	OPT_EARLYM_GREETING =  (1 << 10),
 	OPT_BEEP =             (1 << 11),
 	OPT_SILENT_IF_GREET =  (1 << 12),
+	OPT_READONLY =         (1 << 13),
 };
 
 enum vm_option_args {
@@ -621,7 +626,8 @@ AST_APP_OPTIONS(vm_app_options, {
 	AST_APP_OPTION('U', OPT_MESSAGE_Urgent),
 	AST_APP_OPTION('P', OPT_MESSAGE_PRIORITY),
 	AST_APP_OPTION('e', OPT_EARLYM_GREETING),
-	AST_APP_OPTION_ARG('t', OPT_BEEP, OPT_ARG_BEEP_TONE)
+	AST_APP_OPTION_ARG('t', OPT_BEEP, OPT_ARG_BEEP_TONE),
+	AST_APP_OPTION('r', OPT_READONLY),
 });
 
 static const char * const mailbox_folders[] = {
@@ -10328,7 +10334,7 @@ static int vm_intro(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm
 	}
 }
 
-static int vm_instructions_en(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms, int skipadvanced, int in_urgent)
+static int vm_instructions_en(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms, int skipadvanced, int in_urgent, int nodelete)
 {
 	int res = 0;
 	/* Play instructions and wait for new command */
@@ -10388,10 +10394,12 @@ static int vm_instructions_en(struct ast_channel *chan, struct ast_vm_user *vmu,
 #ifdef IMAP_STORAGE
 				ast_mutex_unlock(&vms->lock);
 #endif
-				if (!curmsg_deleted) {
-					res = ast_play_and_wait(chan, "vm-delete");
-				} else {
-					res = ast_play_and_wait(chan, "vm-undelete");
+				if (!nodelete) {
+					if (!curmsg_deleted) {
+						res = ast_play_and_wait(chan, "vm-delete");
+					} else {
+						res = ast_play_and_wait(chan, "vm-undelete");
+					}
 				}
 				if (!res) {
 					res = ast_play_and_wait(chan, "vm-toforward");
@@ -10416,7 +10424,7 @@ static int vm_instructions_en(struct ast_channel *chan, struct ast_vm_user *vmu,
 	return res;
 }
 
-static int vm_instructions_ja(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms,  int skipadvanced, int in_urgent)
+static int vm_instructions_ja(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms,  int skipadvanced, int in_urgent, int nodelete)
 {
 	int res = 0;
 	/* Play instructions and wait for new command */
@@ -10512,7 +10520,7 @@ static int vm_instructions_ja(struct ast_channel *chan, struct ast_vm_user *vmu,
 	return res;
 }
 
-static int vm_instructions_zh(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms,  int skipadvanced, int in_urgent)
+static int vm_instructions_zh(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms,  int skipadvanced, int in_urgent, int nodelete)
 {
 	int res = 0;
 	/* Play instructions and wait for new command */
@@ -10530,20 +10538,20 @@ static int vm_instructions_zh(struct ast_channel *chan, struct ast_vm_user *vmu,
 			res = ast_play_and_wait(chan, "vm-opts");
 		if (!res) {
 			vms->starting = 0;
-			return vm_instructions_en(chan, vmu, vms, skipadvanced, in_urgent);
+			return vm_instructions_en(chan, vmu, vms, skipadvanced, in_urgent, nodelete);
 		}
 	}
 	return res;
 }
 
-static int vm_instructions(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms, int skipadvanced, int in_urgent)
+static int vm_instructions(struct ast_channel *chan, struct ast_vm_user *vmu, struct vm_state *vms, int skipadvanced, int in_urgent, int nodelete)
 {
 	if (!strncasecmp(ast_channel_language(chan), "ja", 2)) { /* Japanese syntax */
-		return vm_instructions_ja(chan, vmu, vms, skipadvanced, in_urgent);
+		return vm_instructions_ja(chan, vmu, vms, skipadvanced, in_urgent, nodelete);
 	} else if (vms->starting && !strncasecmp(ast_channel_language(chan), "zh", 2)) { /* CHINESE (Taiwan) syntax */
-		return vm_instructions_zh(chan, vmu, vms, skipadvanced, in_urgent);
+		return vm_instructions_zh(chan, vmu, vms, skipadvanced, in_urgent, nodelete);
 	} else {					/* Default to ENGLISH */
-		return vm_instructions_en(chan, vmu, vms, skipadvanced, in_urgent);
+		return vm_instructions_en(chan, vmu, vms, skipadvanced, in_urgent, nodelete);
 	}
 }
 
@@ -11426,6 +11434,7 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
 	int play_auto = 0;
 	int play_folder = 0;
 	int in_urgent = 0;
+	int nodelete = 0;
 #ifdef IMAP_STORAGE
 	int deleted = 0;
 #endif
@@ -11488,6 +11497,9 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
 					play_folder = 0;
 				}
 			}
+			if (ast_test_flag(&flags, OPT_READONLY)) {
+				nodelete = 1;
+			}
 		} else {
 			/* old style options parsing */
 			while (*(args.argv0)) {
@@ -11901,7 +11913,7 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
 			}
 			break;
 		case '7': /* Delete the current message */
-			if (vms.curmsg >= 0 && vms.curmsg <= vms.lastmsg) {
+			if (!nodelete && vms.curmsg >= 0 && vms.curmsg <= vms.lastmsg) {
 				vms.deleted[vms.curmsg] = !vms.deleted[vms.curmsg];
 				if (useadsi)
 					adsi_delete(chan, &vms);
@@ -12090,7 +12102,7 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
 					if (!cmd)
 						cmd = ast_play_and_wait(chan, "vm-opts");
 					if (!cmd)
-						cmd = vm_instructions(chan, vmu, &vms, 1, in_urgent);
+						cmd = vm_instructions(chan, vmu, &vms, 1, in_urgent, nodelete);
 					break;
 				}
 				cmd = ast_play_and_wait(chan, "vm-onefor");
@@ -12102,7 +12114,7 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
 				if (!cmd)
 					cmd = ast_play_and_wait(chan, "vm-opts");
 				if (!cmd)
-					cmd = vm_instructions(chan, vmu, &vms, 1, in_urgent);
+					cmd = vm_instructions(chan, vmu, &vms, 1, in_urgent, nodelete);
 			} else
 				cmd = 0;
 			break;
@@ -12119,7 +12131,7 @@ static int vm_execmain(struct ast_channel *chan, const char *data)
  			break;
 		default:	/* Nothing */
 			ast_test_suite_event_notify("PLAYBACK", "Message: instructions");
-			cmd = vm_instructions(chan, vmu, &vms, 0, in_urgent);
+			cmd = vm_instructions(chan, vmu, &vms, 0, in_urgent, nodelete);
 			break;
 		}
 	}

doc/CHANGES-staging/app_voicemail_nodelete.txt

@@ -0,0 +1,5 @@
+Subject: app_voicemail
+
+The r option has been added, which prevents deletion
+of messages from VoiceMailMain, which can be
+useful for shared mailboxes.