* added the 'source' load-balancing algorithm which uses the source IP(v4|v6)
diff --git a/haproxy.c b/haproxy.c
index 0a935c0..113d0b5 100644
--- a/haproxy.c
+++ b/haproxy.c
@@ -332,7 +332,6 @@
#define PR_O_COOK_PFX 0x00000020 /* rewrite all cookies by prefixing the right serverid */
#define PR_O_COOK_ANY (PR_O_COOK_RW | PR_O_COOK_IND | PR_O_COOK_INS | PR_O_COOK_PFX)
#define PR_O_BALANCE_RR 0x00000040 /* balance in round-robin mode */
-#define PR_O_BALANCE (PR_O_BALANCE_RR)
#define PR_O_KEEPALIVE 0x00000080 /* follow keep-alive sessions */
#define PR_O_FWDFOR 0x00000100 /* insert x-forwarded-for with client address */
#define PR_O_BIND_SRC 0x00000200 /* bind to a specific source address when connect()ing */
@@ -348,6 +347,8 @@
#define PR_O_TCP_SRV_KA 0x00080000 /* enable TCP keep-alive on server-side sessions */
#define PR_O_USE_ALL_BK 0x00100000 /* load-balance between backup servers */
#define PR_O_FORCE_CLO 0x00200000 /* enforce the connection close immediately after server response */
+#define PR_O_BALANCE_SH 0x00400000 /* balance on source IP hash */
+#define PR_O_BALANCE (PR_O_BALANCE_RR | PR_O_BALANCE_SH)
/* various session flags */
#define SN_DIRECT 0x00000001 /* connection made on the server matching the client cookie */
@@ -1862,6 +1863,69 @@
/*
+ * This function tries to find a running server for the proxy <px> following
+ * the source hash method. Depending on the number of active/backup servers,
+ * it will either look for active servers, or for backup servers.
+ * If any server is found, it will be returned. If no valid server is found,
+ * NULL is returned.
+ */
+static inline struct server *get_server_sh(struct proxy *px, char *addr, int len) {
+ struct server *srv;
+
+ if (px->srv_act) {
+ unsigned int h, l;
+
+ l = h = 0;
+ if (px->srv_act > 1) {
+ while ((l + sizeof (int)) <= len) {
+ h ^= ntohl(*(unsigned int *)(&addr[l]));
+ l += sizeof (int);
+ }
+ h %= px->srv_act;
+ }
+
+ for (srv = px->srv; srv; srv = srv->next) {
+ if ((srv->state & (SRV_RUNNING | SRV_BACKUP)) == SRV_RUNNING) {
+ if (!h)
+ return srv;
+ h--;
+ }
+ }
+ /* note that theorically we should not get there */
+ }
+
+ if (px->srv_bck) {
+ unsigned int h, l;
+
+ /* By default, we look for the first backup server if all others are
+ * DOWN. But in some cases, it may be desirable to load-balance across
+ * all backup servers.
+ */
+ l = h = 0;
+ if (px->srv_bck > 1 && px->options & PR_O_USE_ALL_BK) {
+ while ((l + sizeof (int)) <= len) {
+ h ^= ntohl(*(unsigned int *)(&addr[l]));
+ l += sizeof (int);
+ }
+ h %= px->srv_bck;
+ }
+
+ for (srv = px->srv; srv; srv = srv->next) {
+ if (srv->state & SRV_RUNNING) {
+ if (!h)
+ return srv;
+ h--;
+ }
+ }
+ /* note that theorically we should not get there */
+ }
+
+ /* if we get there, it means there are no available servers at all */
+ return NULL;
+}
+
+
+/*
* This function initiates a connection to the current server (s->srv) if (s->direct)
* is set, or to the dispatch server if (s->direct) is 0.
* It can return one of :
@@ -1884,6 +1948,7 @@
s->srv_addr = s->srv->addr;
}
else if (s->proxy->options & PR_O_BALANCE) {
+ /* Ensure that srv will not be NULL */
if (!s->proxy->srv_act && !s->proxy->srv_bck)
return SN_ERR_SRVTO;
@@ -1891,10 +1956,26 @@
struct server *srv;
srv = get_server_rr(s->proxy);
- /* srv cannot be NULL */
s->srv_addr = srv->addr;
s->srv = srv;
}
+ else if (s->proxy->options & PR_O_BALANCE_SH) {
+ struct server *srv;
+ int len;
+
+ if (s->cli_addr.ss_family == AF_INET)
+ len = 4;
+ else if (s->cli_addr.ss_family == AF_INET6)
+ len = 16;
+ else /* unknown IP family */
+ return SN_ERR_INTERNAL;
+
+ srv = get_server_sh(s->proxy,
+ (void *)&((struct sockaddr_in *)&s->cli_addr)->sin_addr,
+ len);
+ s->srv_addr = srv->addr;
+ s->srv = srv;
+ }
else /* unknown balancing algorithm */
return SN_ERR_INTERNAL;
}
@@ -6846,8 +6927,11 @@
if (!strcmp(args[1], "roundrobin")) {
curproxy->options |= PR_O_BALANCE_RR;
}
+ else if (!strcmp(args[1], "source")) {
+ curproxy->options |= PR_O_BALANCE_SH;
+ }
else {
- Alert("parsing [%s:%d] : '%s' only supports 'roundrobin' option.\n", file, linenum, args[0]);
+ Alert("parsing [%s:%d] : '%s' only supports 'roundrobin' and 'source' options.\n", file, linenum, args[0]);
return -1;
}
}