[Qemu-devel] [RFC][PATCH 08/15] virtproxy: interfaces to set/remove/handle VPOForwards

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Functions to add listener FDs (oforwards) which set up proxied connections
to associated service, and the corresponding handler function to process
to new connections to said FDs and initialize new client connections to
the associated remote server over the channel

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 virtproxy.c |  103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 virtproxy.h |    1 +
 2 files changed, 104 insertions(+), 0 deletions(-)

diff --git a/virtproxy.c b/virtproxy.c
index cc0ac9a..6c3611b 100644
--- a/virtproxy.c
+++ b/virtproxy.c
@@ -12,6 +12,7 @@
  */
 
 #include "virtproxy.h"
+#include "qemu_socket.h"
 
 #define DEBUG_VP
 
@@ -314,6 +315,70 @@ static void vp_channel_read(void *opaque)
     }
 }
 
+/* handler to accept() and init new client connections */
+static void vp_oforward_accept(void *opaque)
+{
+    VPOForward *f = opaque;
+    VPDriver *drv = f->drv;
+
+    struct sockaddr_in saddr;
+    struct sockaddr *addr;
+    socklen_t len;
+    int fd, ret;
+    VPConn *conn = NULL;
+    VPPacket pkt;
+    VPControlMsg msg;
+
+    TRACE("called with opaque: %p, drv: %p", f, drv);
+
+    for(;;) {
+        len = sizeof(saddr);
+        addr = (struct sockaddr *)&saddr;
+        fd = qemu_accept(f->listen_fd, addr, &len);
+
+        if (fd < 0 && errno != EINTR) {
+            TRACE("accept() failed");
+            return;
+        } else if (fd >= 0) {
+            TRACE("accepted connection");
+            break;
+        }
+    }
+
+    if (drv->channel_fd == -1) {
+        TRACE("communication channel not open, closing connection");
+        closesocket(fd);
+        return;
+    }
+
+    /* send init packet over channel */
+    memset(&msg, 0, sizeof(VPControlMsg));
+    msg.type = VP_CONTROL_CONNECT_INIT;
+    msg.args.connect_init.client_fd = fd;
+    pstrcpy(msg.args.connect_init.service_id, VP_SERVICE_ID_LEN, f->service_id);
+
+    memset(&pkt, 0, sizeof(VPPacket));
+    pkt.type = VP_PKT_CONTROL;
+    pkt.payload.msg = msg;
+    pkt.magic = VP_MAGIC;
+
+    ret = vp_send_all(drv->channel_fd, &pkt, sizeof(VPPacket));
+    if (ret == -1) {
+        LOG("vp_send_all() failed");
+        return;
+    }
+
+    /* create new VPConn for client */
+    conn = qemu_mallocz(sizeof(VPConn));
+    conn->drv = drv;
+    conn->client_fd = fd;
+    conn->type = VP_CONN_CLIENT;
+    conn->state = VP_STATE_NEW;
+    QLIST_INSERT_HEAD(&drv->conns, conn, next);
+
+    socket_set_nonblock(fd);
+}
+
 /* create/init VPDriver object */
 VPDriver *vp_new(int fd, bool listen)
 {
@@ -336,3 +401,41 @@ VPDriver *vp_new(int fd, bool listen)
 
     return drv;
 }
+
+/* set/modify/remove a service_id -> net/unix listening socket mapping
+ *
+ * "service_id" is a user-defined id for the service. this is what the
+ * client end will tag it's connections with so that the remote end can
+ * route it to the proper socket on the remote end.
+ *
+ * "fd" is a listen()'ing socket we want virtproxy to listen for new
+ * connections of this service type on. set "fd" to -1 to remove the 
+ * existing listening socket for this "service_id"
+ */
+int vp_set_oforward(VPDriver *drv, int fd, const char *service_id)
+{
+    VPOForward *f = get_oforward(drv, service_id);
+
+    if (fd == -1) {
+        if (f != NULL) {
+            vp_set_fd_handler(f->listen_fd, NULL, NULL, NULL);
+            QLIST_REMOVE(f, next);
+            qemu_free(f);
+        }
+        return 0;
+    }
+
+    if (f == NULL) {
+        f = qemu_mallocz(sizeof(VPOForward));
+        f->drv = drv;
+        strncpy(f->service_id, service_id, VP_SERVICE_ID_LEN);
+        QLIST_INSERT_HEAD(&drv->oforwards, f, next);
+    } else {
+        closesocket(f->listen_fd);
+    }
+
+    f->listen_fd = fd;
+    vp_set_fd_handler(f->listen_fd, vp_oforward_accept, NULL, f);
+
+    return 0;
+}
diff --git a/virtproxy.h b/virtproxy.h
index 3df1691..39d5d40 100644
--- a/virtproxy.h
+++ b/virtproxy.h
@@ -33,5 +33,6 @@ int vp_set_fd_handler(int fd,
 
 /* virtproxy interface */
 VPDriver *vp_new(int fd, bool listen);
+int vp_set_oforward(VPDriver *drv, int fd, const char *service_id);
 
 #endif /* VIRTPROXY_H */
-- 
1.7.0.4