Add a VBE_TryConnect() which tries to connected to a given backend+addrinfo

combination.  This will be necessary in most if not all backend methods,
so it should be generic.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@1963 d4fa192b-c00b-0410-8231-f00ffab90ce4

diff --git a/varnish-cache/bin/varnishd/cache.h b/varnish-cache/bin/varnishd/cache.h
index 01f4b6d4a72f7eb8d84a3f01379c068cf93fe588..0c3e1f61ba9ff87323c27b405f47c10b04613f81 100644 (file)
--- a/varnish-cache/bin/varnishd/cache.h
+++ b/varnish-cache/bin/varnishd/cache.h
@@ -68,6 +68,7 @@ struct sess;
 struct object;
 struct objhead;
 struct workreq;
+struct addrinfo;
 
 /*--------------------------------------------------------------------*/
 
@@ -399,6 +400,7 @@ struct backend *VBE_NewBackend(struct backend_method *method);
 struct vbe_conn *VBE_NewConn(void);
 void VBE_ReleaseConn(struct vbe_conn *);
 void VBE_UpdateHealth(struct sess *sp, struct vbe_conn *, int);
+int VBE_TryConnect(struct sess *sp, struct addrinfo *ai);
 
 /* cache_backend_simple.c */
 extern struct backend_method   backend_method_simple;

diff --git a/varnish-cache/bin/varnishd/cache_backend.c b/varnish-cache/bin/varnishd/cache_backend.c
index cad9b4880c3a063005d4eacbe2742e04579cc005..da8ecc1c2b341ac8ac73059a03baa7a9beb9b887 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_backend.c
+++ b/varnish-cache/bin/varnishd/cache_backend.c
@@ -33,8 +33,12 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
+#include <sys/socket.h>
+#include <netdb.h>
+
 #include "heritage.h"
 #include "shmlog.h"
 #include "cache.h"
@@ -46,6 +50,64 @@ static MTX VBE_mtx;
 
 struct backendlist backendlist = TAILQ_HEAD_INITIALIZER(backendlist);
 
+
+/*--------------------------------------------------------------------
+ * Attempt to connect to a given addrinfo entry.
+ *
+ * Must be called with locked backend, but will release the backend
+ * lock during the slow/sleeping stuff, so that other worker threads
+ * can have a go, while we ponder.
+ *
+ */
+
+int
+VBE_TryConnect(struct sess *sp, struct addrinfo *ai)
+{
+       struct sockaddr_storage ss;
+       int fam, sockt, proto;
+       socklen_t alen;
+       int s;
+       char abuf1[TCP_ADDRBUFSIZE], abuf2[TCP_ADDRBUFSIZE];
+       char pbuf1[TCP_PORTBUFSIZE], pbuf2[TCP_PORTBUFSIZE];
+
+       /*
+        * ai is only valid with the lock held, so copy out the bits
+        * we need to make the connection
+        */
+       fam = ai->ai_family;
+       sockt = ai->ai_socktype;
+       proto = ai->ai_protocol;
+       alen = ai->ai_addrlen;
+       assert(alen <= sizeof ss);
+       memcpy(&ss, ai->ai_addr, alen);
+
+       /* release lock during stuff that can take a long time */
+       UNLOCK(&sp->backend->mtx);
+
+       s = socket(fam, sockt, proto);
+       if (s < 0) {
+               LOCK(&sp->backend->mtx);
+               return (s);
+       }
+
+       if (connect(s, (void *)&ss, alen) != 0) {
+               close(s);
+               LOCK(&sp->backend->mtx);
+               return (-1);
+       }
+
+       TCP_myname(s, abuf1, sizeof abuf1, pbuf1, sizeof pbuf1);
+       TCP_name((void*)&ss, alen,
+           abuf2, sizeof abuf2, pbuf2, sizeof pbuf2);
+       WSL(sp->wrk, SLT_BackendOpen, s, "%s %s %s %s %s",
+           sp->backend->vcl_name, abuf1, pbuf1, abuf2, pbuf2);
+
+       LOCK(&sp->backend->mtx);
+       return (s);
+}
+
+
+
 /*--------------------------------------------------------------------
  * Get a http structure for talking to the backend.
  */