ubusd: implement protocol support for passing file descriptors as part of request...

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/ubusd.c b/ubusd.c
index 59dee3e6d92acb2a0bfb9fd5311aeddb7f25bd1c..bcc8603a60be678733ed5f4623d48eae4746a98e 100644 (file)
--- a/ubusd.c
+++ b/ubusd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License version 2.1
@@ -14,6 +14,9 @@
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/uio.h>
+#ifdef FreeBSD
+#include <sys/param.h>
+#endif
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -59,6 +62,8 @@ struct ubus_msg_buf *ubus_msg_new(void *data, int len, bool shared)
        if (!ub)
                return NULL;
 
+       ub->fd = -1;
+
        if (shared) {
                ub->refcount = ~0;
                ub->data = data;
@@ -78,6 +83,9 @@ void ubus_msg_free(struct ubus_msg_buf *ub)
        switch (ub->refcount) {
        case 1:
        case ~0:
+               if (ub->fd >= 0)
+                       close(ub->fd);
+
                free(ub);
                break;
        default:
@@ -88,14 +96,37 @@ void ubus_msg_free(struct ubus_msg_buf *ub)
 
 static int ubus_msg_writev(int fd, struct ubus_msg_buf *ub, int offset)
 {
-       struct iovec iov[2];
+       static struct iovec iov[2];
+       static struct {
+               struct cmsghdr h;
+               int fd;
+       } fd_buf = {
+               .h = {
+                       .cmsg_len = sizeof(fd_buf),
+                       .cmsg_level = SOL_SOCKET,
+                       .cmsg_type = SCM_RIGHTS,
+               },
+       };
+       struct msghdr msghdr = {
+               .msg_iov = iov,
+               .msg_iovlen = ARRAY_SIZE(iov),
+               .msg_control = &fd_buf,
+               .msg_controllen = sizeof(fd_buf),
+       };
+
+       fd_buf.fd = ub->fd;
+       if (ub->fd < 0) {
+               msghdr.msg_control = NULL;
+               msghdr.msg_controllen = 0;
+       }
 
        if (offset < sizeof(ub->hdr)) {
                iov[0].iov_base = ((char *) &ub->hdr) + offset;
                iov[0].iov_len = sizeof(ub->hdr) - offset;
                iov[1].iov_base = (char *) ub->data;
                iov[1].iov_len = ub->len;
-               return writev(fd, iov, 2);
+
+               return sendmsg(fd, &msghdr, 0);
        } else {
                offset -= sizeof(ub->hdr);
                return write(fd, ((char *) ub->data) + offset, ub->len - offset);
@@ -160,6 +191,8 @@ static void handle_client_disconnect(struct ubus_client *cl)
                ubus_msg_dequeue(cl);
 
        ubusd_proto_free_client(cl);
+       if (cl->pending_msg_fd >= 0)
+               close(cl->pending_msg_fd);
        uloop_fd_delete(&cl->sock);
        close(cl->sock.fd);
        free(cl);
@@ -169,6 +202,21 @@ static void client_cb(struct uloop_fd *sock, unsigned int events)
 {
        struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
        struct ubus_msg_buf *ub;
+       static struct iovec iov;
+       static struct {
+               struct cmsghdr h;
+               int fd;
+       } fd_buf = {
+               .h = {
+                       .cmsg_type = SCM_RIGHTS,
+                       .cmsg_level = SOL_SOCKET,
+                       .cmsg_len = sizeof(fd_buf),
+               }
+       };
+       struct msghdr msghdr = {
+               .msg_iov = &iov,
+               .msg_iovlen = 1,
+       };
 
        /* first try to tx more pending data */
        while ((ub = ubus_msg_head(cl))) {
@@ -203,10 +251,26 @@ retry:
                int offset = cl->pending_msg_offset;
                int bytes;
 
-               bytes = read(sock->fd, (char *)&cl->hdrbuf + offset, sizeof(cl->hdrbuf) - offset);
+               fd_buf.fd = -1;
+
+               iov.iov_base = &cl->hdrbuf + offset;
+               iov.iov_len = sizeof(cl->hdrbuf) - offset;
+
+               if (cl->pending_msg_fd < 0) {
+                       msghdr.msg_control = &fd_buf;
+                       msghdr.msg_controllen = sizeof(fd_buf);
+               } else {
+                       msghdr.msg_control = NULL;
+                       msghdr.msg_controllen = 0;
+               }
+
+               bytes = recvmsg(sock->fd, &msghdr, 0);
                if (bytes < 0)
                        goto out;
 
+               if (fd_buf.fd >= 0)
+                       cl->pending_msg_fd = fd_buf.fd;
+
                cl->pending_msg_offset += bytes;
                if (cl->pending_msg_offset < sizeof(cl->hdrbuf))
                        goto out;
@@ -240,6 +304,8 @@ retry:
                }
 
                /* accept message */
+               ub->fd = cl->pending_msg_fd;
+               cl->pending_msg_fd = -1;
                cl->pending_msg_offset = 0;
                cl->pending_msg = NULL;
                ubusd_proto_receive_message(cl, ub);

diff --git a/ubusd.h b/ubusd.h
index cab984b42b50dbb8c6f5534411ceddfd9faf2015..1c6cd7feadf9730d3cca245e7bb2cdf10b9e1cf4 100644 (file)
--- a/ubusd.h
+++ b/ubusd.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License version 2.1
@@ -31,6 +31,7 @@ struct ubus_msg_buf {
        uint32_t refcount; /* ~0: uses external data buffer */
        struct ubus_msghdr hdr;
        struct blob_attr *data;
+       int fd;
        int len;
 };
 
@@ -45,6 +46,7 @@ struct ubus_client {
 
        struct ubus_msg_buf *pending_msg;
        int pending_msg_offset;
+       int pending_msg_fd;
        struct {
                struct ubus_msghdr hdr;
                struct blob_attr data;

diff --git a/ubusd_proto.c b/ubusd_proto.c
index fd38dbdafc920ac196dd991e8d75c5d7e5177fe8..811aa79f478782544e2ee236e09da0a21832a468 100644 (file)
--- a/ubusd_proto.c
+++ b/ubusd_proto.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License version 2.1
@@ -12,6 +12,8 @@
  */
 
 #include <arpa/inet.h>
+#include <unistd.h>
+
 #include "ubusd.h"
 
 struct blob_buf b;
@@ -38,6 +40,15 @@ static struct blob_attr **ubus_parse_msg(struct blob_attr *msg)
        return attrbuf;
 }
 
+static void ubus_msg_close_fd(struct ubus_msg_buf *ub)
+{
+       if (ub->fd < 0)
+               return;
+
+       close(ub->fd);
+       ub->fd = -1;
+}
+
 static void ubus_msg_init(struct ubus_msg_buf *ub, uint8_t type, uint16_t seq, uint32_t peer)
 {
        ub->hdr.version = 0;
@@ -409,6 +420,9 @@ void ubusd_proto_receive_message(struct ubus_client *cl, struct ubus_msg_buf *ub
        if (ub->hdr.type < __UBUS_MSG_LAST)
                cb = handlers[ub->hdr.type];
 
+       if (ub->hdr.type != UBUS_MSG_STATUS)
+               ubus_msg_close_fd(ub);
+
        if (cb)
                ret = cb(cl, ub, ubus_parse_msg(ub->data));
        else
@@ -434,6 +448,7 @@ struct ubus_client *ubusd_proto_new_client(int fd, uloop_fd_handler cb)
        INIT_LIST_HEAD(&cl->objects);
        cl->sock.fd = fd;
        cl->sock.cb = cb;
+       cl->pending_msg_fd = -1;
 
        if (!ubus_alloc_id(&clients, &cl->id, 0))
                goto free;