From: Julian Anastasov <ja@xxxxxx>

ipvsadm: one-packet scheduling

Allow one-packet scheduling for UDP connections. When the fwmark-based or
normal virtual service is marked with '-o' or '--ops' options all
connections are created only to schedule one packet. Useful to schedule UDP
packets from same client port to different real servers. Recommended with
RR or WRR schedulers (the connections are not visible with ipvsadm -L).

Up-port of http://www.ssi.bg/~ja/tmp/ops-ipvsadm-1.21-1.diff to
ipvsadm-1.24-10 by Simon Horman.

Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>

Index: ipvsadm-1.24-10/ipvsadm.c
===================================================================
--- ipvsadm-1.24-10.orig/ipvsadm.c	2004-01-10 18:39:03.000000000 +0900
+++ ipvsadm-1.24-10/ipvsadm.c	2010-04-13 10:57:53.000000000 +0900
@@ -182,7 +182,8 @@ static const char* cmdnames[] = {
 #define OPT_PERSISTENTCONN	0x20000
 #define OPT_SORT		0x40000
 #define OPT_SYNCID		0x80000
-#define NUMBER_OF_OPT		20
+#define OPT_ONEPACKET		0x200000
+#define NUMBER_OF_OPT		21
 
 static const char* optnames[] = {
 	"numeric",
@@ -205,6 +206,7 @@ static const char* optnames[] = {
 	"persistent-conn",
 	"sort",
 	"syncid",
+	"ops",
 };
 
 /*
@@ -388,6 +390,7 @@ parse_options(int argc, char **argv, str
 		{"thresholds", '\0', POPT_ARG_NONE, NULL, '9'},
 		{"persistent-conn", '\0', POPT_ARG_NONE, NULL, 'P'},
 		{"sort", '\0', POPT_ARG_NONE, NULL, '0'},
+		{"ops", 'o', POPT_ARG_NONE, NULL, 'o'},
 		{NULL, 0, 0, NULL, 0}
 	};
 
@@ -492,7 +495,7 @@ parse_options(int argc, char **argv, str
 			break;
 		case 'p':
 			set_option(options, OPT_PERSISTENT);
-			ce->svc.flags = IP_VS_SVC_F_PERSISTENT;
+			ce->svc.flags |= IP_VS_SVC_F_PERSISTENT;
 			ce->svc.timeout =
 				parse_timeout(optarg, 1, MAX_TIMEOUT);
 			break;
@@ -590,6 +593,10 @@ parse_options(int argc, char **argv, str
 			set_option(options, OPT_SORT);
 			*format |= FMT_SORT;
 			break;
+		case 'o':
+			set_option(options, OPT_ONEPACKET);
+			ur->vs_flags |= IP_VS_SVC_F_ONEPACKET;
+			break;
 		default:
 			fail(2, "invalid option `%s'",
 			     poptBadOption(context, POPT_BADOPTION_NOALIAS));
@@ -636,7 +643,7 @@ parse_options(int argc, char **argv, str
 	      unsigned int *options, unsigned int *format)
 {
 	int c, parse;
-	const char *optstring = "AEDCZSRaedlLhvt:u:f:s:M:p::r:gmiw:x:y:cn";
+	const char *optstring = "AEDCZSRaedlLhvt:u:f:s:M:p::r:gmiw:x:y:cno";
 	const struct option long_options[] = {
 		{"add-service", 0, 0, 'A'},
 		{"edit-service", 0, 0, 'E'},
@@ -678,6 +685,7 @@ parse_options(int argc, char **argv, str
 		{"thresholds", 0, 0, '9'},
 		{"persistent-conn", 0, 0, 'P'},
 		{"sort", 0, 0, '0'},
+		{"ops", 0, 0, 'o'},
 		{"help", 0, 0, 'h'},
 		{0, 0, 0, 0}
 	};
@@ -801,7 +809,7 @@ parse_options(int argc, char **argv, str
 			break;
 		case 'p':
 			set_option(options, OPT_PERSISTENT);
-			ce->svc.flags = IP_VS_SVC_F_PERSISTENT;
+			ce->svc.flags |= IP_VS_SVC_F_PERSISTENT;
 			if (!optarg && optind < argc && argv[optind][0] != '-'
 			    && argv[optind][0] != '!')
 				optarg = argv[optind++];
@@ -902,6 +910,10 @@ parse_options(int argc, char **argv, str
 			set_option(options, OPT_SORT);
 			*format |= FMT_SORT;
 			break;
+		case 'o':
+			set_option(options, OPT_ONEPACKET);
+			ce->svc.flags |= IP_VS_SVC_F_ONEPACKET;
+			break;
 		default:
 			fail(2, "invalid option `%s'", argv[optind-1]);
 		}
@@ -960,10 +972,15 @@ static int process_options(int argc, cha
 	if (ce.cmd == CMD_ADD || ce.cmd == CMD_EDIT) {
 		/* Make sure that port zero service is persistent */
 		if (!ce.svc.fwmark && !ce.svc.port &&
-		    (ce.svc.flags != IP_VS_SVC_F_PERSISTENT))
+		    !(ce.svc.flags & IP_VS_SVC_F_PERSISTENT))
 			fail(2, "Zero port specified "
 			     "for non-persistent service");
 
+		if (ce.svc.flags & IP_VS_SVC_F_ONEPACKET &&
+		    !ce.svc.fwmark && ce.svc.protocol != IPPROTO_UDP)
+			fail(2, "One-Packet Scheduling is only "
+			     "for UDP virtual services");
+
 		/* Set the default scheduling algorithm if not specified */
 		if (strlen(ce.svc.sched_name) == 0)
 			strcpy(ce.svc.sched_name, DEF_SCHED);
@@ -1328,6 +1345,7 @@ static void usage_exit(const char *progr
 		"  --thresholds                        output of thresholds information\n"
 		"  --persistent-conn                   output of persistent connection info\n"
 		"  --sort                              sorting output of service/server entries\n"
+		"  --ops          -o                   one-packet scheduling\n"
 		"  --numeric      -n                   numeric output of addresses and ports\n",
 		DEF_SCHED);
 
@@ -1629,6 +1647,8 @@ print_service_entry(ipvs_service_entry_t
 				printf(" -M %s", inet_ntoa(mask));
 			}
 		}
+		if (se->flags & IP_VS_SVC_F_ONEPACKET)
+			printf(" ops");
 	} else if (format & FMT_STATS) {
 		printf("%-33s", svc_name);
 		print_largenum(se->stats.conns);
@@ -1653,6 +1673,8 @@ print_service_entry(ipvs_service_entry_t
 				printf(" mask %s", inet_ntoa(mask));
 			}
 		}
+		if (se->flags & IP_VS_SVC_F_ONEPACKET)
+			printf(" ops");
 	}
 	printf("\n");