From eca2f3484fe6dadf5af9f8d1ff702d967ddeddf3 Mon Sep 17 00:00:00 2001
From: Gerrit Renker <grenker@cscs.ch>
Date: Sun, 13 Jun 2010 11:30:47 +0200
Subject: [PATCH] udp: refuse to add the same target twice

Based on the preceding patches, this turns the UDP targets list into a set.
---
 error.h    |  6 +++++-
 udp_send.c | 42 ++++++++++++++++++++++++++++--------------
 2 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/error.h b/error.h
index 31903062..f687a4cb 100644
--- a/error.h
+++ b/error.h
@@ -16,7 +16,6 @@ DEFINE_ERRLIST_OBJECT_ENUM;
 #define TIME_ERRORS
 #define CLOSE_ON_FORK_ERRORS
 #define DAEMON_ERRORS
-#define UDP_SEND_ERRORS
 #define GUI_ERRORS
 #define RINGBUFFER_ERRORS
 #define SCORE_ERRORS
@@ -235,6 +234,11 @@ extern const char **para_errlist[];
 	PARA_ERROR(UDP_OVERRUN, "output buffer overrun"), \
 
 
+#define UDP_SEND_ERRORS \
+	PARA_ERROR(TARGET_EXISTS, "requested target is already present"),\
+	PARA_ERROR(TARGET_NOT_FOUND, "requested target not found")
+
+
 #define HTTP_RECV_ERRORS \
 	PARA_ERROR(HTTP_RECV_OVERRUN, "http_recv: output buffer overrun"), \
 
diff --git a/udp_send.c b/udp_send.c
index 8baf15e3..71e85b79 100644
--- a/udp_send.c
+++ b/udp_send.c
@@ -213,14 +213,13 @@ static int udp_com_off(__a_unused struct sender_command_data *scd)
 	return 1;
 }
 
-static int udp_com_delete(struct sender_command_data *scd)
+static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
 {
 	struct sender_client *sc, *tmp;
 	char host[MAX_HOSTLEN];
 	int32_t port;
 
 	list_for_each_entry_safe(sc, tmp, &targets, node) {
-		struct udp_target *ut = sc->private_data;
 		parse_url(sc->name, host, sizeof(host), &port);
 
 		/* Unspecified port means wildcard port match */
@@ -228,9 +227,22 @@ static int udp_com_delete(struct sender_command_data *scd)
 			continue;
 		if (strcmp(host, scd->host))
 			continue;
+		return sc;
+	}
+	return NULL;
+}
+
+static int udp_com_delete(struct sender_command_data *scd)
+{
+	struct udp_target *ut = sc->private_data;
+	struct sender_client *sc = udp_lookup_target(scd);
+
+	if (sc) {
 		udp_delete_target(ut, "com_delete");
+		return 1;
 	}
-	return 1;
+	PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
+	return -E_TARGET_NOT_FOUND;
 }
 
 /** Initialize UDP session and set maximum payload size. */
@@ -316,18 +328,25 @@ fail:
 	return ret;
 }
 
-static void udp_add_target(struct sender_command_data *scd)
+static int udp_com_add(struct sender_command_data *scd)
 {
 	int ret;
-	struct udp_target *ut = para_calloc(sizeof(*ut));
+	struct udp_target *ut;
+	struct sender_client *sc = udp_lookup_target(scd);
 
+	if (sc) {
+		PARA_NOTICE_LOG("target %s already exists - not adding it\n",
+				sc->name);
+		return -E_TARGET_EXISTS;
+	}
+	ut = para_calloc(sizeof(*ut));
+	sc = ut->sc = para_calloc(sizeof(*sc));
 	ut->fcp.slices_per_group      = scd->slices_per_group;
 	ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 	ut->fcp.max_slice_bytes	      = scd->max_slice_bytes;
 	ut->fcp.init_fec	      = udp_init_fec;
 	ut->fcp.send_fec	      = udp_send_fec;
 
-	ut->sc = para_calloc(sizeof(*ut->sc));
 	ut->sc->private_data = ut;
 	ut->sc->fd = -1;
 	ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
@@ -345,7 +364,7 @@ static void udp_add_target(struct sender_command_data *scd)
 	PARA_INFO_LOG("adding to target list (%s)\n", ut->sc->name);
 	ut->fc = vss_add_fec_client(ut->sc, &ut->fcp);
 	para_list_add(&ut->sc->node, &targets);
-	return;
+	return 1;
 err:
 	if (ut->sc->fd >= 0)
 		close(ut->sc->fd);
@@ -353,12 +372,7 @@ err:
 			scd->host, scd->port, para_strerror(-ret));
 	free(ut->sc);
 	free(ut);
-}
-
-static int udp_com_add(struct sender_command_data *scd)
-{
-	udp_add_target(scd);
-	return 1;
+	return ret;
 }
 
 static char *udp_info(void)
@@ -401,7 +415,7 @@ static void udp_init_target_list(void)
 			PARA_CRIT_LOG("not adding requested target '%s'\n",
 					conf.udp_target_arg[i]);
 		else
-			udp_add_target(&scd);
+			udp_com_add(&scd);
 	}
 }
 
-- 
2.39.2