Merge pull request #2436 from pqarmitage/updates

Fix ip_vs module loading on RHEL based distros

INSTALL

@@ -129,6 +129,11 @@ For building the documentation, the following packages need to be installed:
    For latex or pdf files, the following are also needed:
 	texlive-core texlive-bin texlive-latexextra
 
+openSUSE
+========
+    1. zypper install -t pattern devel_C_C++
+    2. Install packages with same names as Red Hat variants (except libopenssl-devel instead of openssl-devel and libkmod-devel instead of kmod-devel)
+
 Kernel configuration requirements
 ---------------------------------
 The following list is probably incomplete, and will be updated as other
@@ -150,6 +155,8 @@ NETFILTER_XTABLES - if strict_mode or no_accept.
 NF_TABLES and associated components - to use nftables for strict_mode or no_accept
 IP_ADVANCED_ROUTER and various associated options if static/dynamic routes specified
 FIB_RULES if static or dynamic rules are specified
+PROC_EVENTS for track_process
+
 
 Installing from a git repo
 ==========================

keepalived/check/ipvswrapper.c

@@ -88,8 +88,8 @@ ipvs_start(void)
 {
 	log_message(LOG_DEBUG, "%snitializing ipvs", reload ? "Rei" : "I");
 	/* Initialize IPVS module */
-	if (ipvs_init()) {
-		if (!keepalived_modprobe("ip_vs") || ipvs_init()) {
+	if (ipvs_init(false)) {
+		if (!keepalived_modprobe("ip_vs") || ipvs_init(true)) {
 			log_message(LOG_INFO, "IPVS: Can't initialize ipvs: %s",
 			       ipvs_strerror(errno));
 			no_ipvs = true;
@@ -879,9 +879,7 @@ ipvs_update_rs_stats(virtual_server_t *vs, uint16_t af, uint32_t fwmark, union n
 		else {
 			/* Search for a match in the list of real servers */
 			rs_match = NULL;
-			int no = 0;
 			list_for_each_entry(rs, &vs->rs, e_list) {
-				no++;
 				if (vsd_equal(rs, &dests->user.entrytable[i])) {
 					rs_match = rs;
 					break;

keepalived/check/libipvs.c

@@ -385,28 +385,53 @@ static int ipvs_getinfo_parse_cb(struct nl_msg *msg, __attribute__((unused)) voi
 }
 #endif
 
-static int ipvs_getinfo(void)
+static int ipvs_getinfo(bool retry)
 {
 	socklen_t len;
 	struct ip_vs_getinfo ipvs_info;
+	unsigned retries = retry ? 1 : 0;
+
+	/* It appears that if we need to install the ip_vs module
+	 * (via keepalived_modprobe), then the first ipvs_nl_send_message()
+	 * call afterwards fails, but it succeeds thereafter.
+	 *
+	 * On some distros the call genl_ctrl_resolve(sock, IPVS_GENL_NAME) loads
+	 * the ip_vs module, so we don't need to call keepalived_modprobe(), and
+	 * we don't need to retry the ipvs_nl_send_message(). On the other hand,
+	 * if genl_ctrl_resolve() does not load the ip_vs module, then we need to
+	 * make the second call of ipvs_nl_send_message().
+	 *
+	 * It appears that if there is an entry:
+	 *   alias net-pf-16-proto-16-family-IPVS ip_vs
+	 * in /lib/modules/{KERNEL_VER}/modules.alias then genl_ctrl_resolve() causes
+	 * the ip_vs module to be loaded, and if there is no such entry, then it does
+	 * not load the ip_vs module. Whether this is cause and effect, or whether they
+	 * are both caused by some other aspect of the configuration I do not know.
+	 */
 
 	ipvs_func = ipvs_getinfo;
 
 #ifdef LIBIPVS_USE_NL
 	if (try_nl) {
 		struct nl_msg *msg;
-		if (!(msg = ipvs_nl_message(IPVS_CMD_GET_INFO, 0)))
-			return -1;
 
-		return ipvs_nl_send_message(msg, ipvs_getinfo_parse_cb, NULL);
+		do {
+			if (!(msg = ipvs_nl_message(IPVS_CMD_GET_INFO, 0)))
+				return -1;
+
+			if (!ipvs_nl_send_message(msg, ipvs_getinfo_parse_cb, NULL))
+				return 0;
+		} while (retries--);
+
+		return -1;
 	}
 #endif
 
 	len = sizeof(ipvs_info);
 	return getsockopt(sockfd, IPPROTO_IP, IP_VS_SO_GET_INFO, &ipvs_info, &len);
 }
 
-int ipvs_init(void)
+int ipvs_init(bool retry)
 {
 	ipvs_func = ipvs_init;
 
@@ -417,8 +442,8 @@ int ipvs_init(void)
 		log_message(LOG_INFO, "Note: IPVS with IPv6 will not be supported");
 #endif
 
-	if (try_nl && ipvs_nl_send_message(NULL, NULL, NULL) == 0)
-		return ipvs_getinfo();
+	if (try_nl)
+		return ipvs_getinfo(retry);
 
 	try_nl = false;
 #else
@@ -429,7 +454,7 @@ int ipvs_init(void)
 	if (sockfd == -1)
 		return -1;
 
-	if (ipvs_getinfo()) {
+	if (ipvs_getinfo(false)) {
 		close(sockfd);
 		sockfd = -1;
 		return -1;

keepalived/include/libipvs.h

@@ -34,7 +34,7 @@ typedef struct ip_vs_dest_entry_app	ipvs_dest_entry_t;
 
 
 /* init socket and get ipvs info */
-extern int ipvs_init(void);
+extern int ipvs_init(bool);
 
 /* Set timeout parameters */
 extern int ipvs_set_timeout(const ipvs_timeout_t *to);