[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1288232669-8927-1-git-send-email-x@jeffhansen.com>
Date: Thu, 28 Oct 2010 02:24:29 +0000
From: x@...fhansen.com
To: netdev@...r.kernel.org
Cc: Dave Miller <davem@...emloft.net>, Jeff Hansen <x@...fhansen.com>
Subject: [PATCH 1/1] net/unix: Allow Unix sockets to be treated like normal files
From: Jeff Hansen <x@...fhansen.com>
Resent. Is there anything else I need to do for this patch to get reviewed
and/or merged? Any comments by anyone?
This allows Unix sockets to be opened, written, read, and closed, like
normal files. This can be especially handy from, for example, a shell
script that wants to send a short message to a Unix socket, but doesn't
want to and/or cannot create the socket itself.
This will try to open the Unix socket first in SOCK_DGRAM mode, then
SOCK_STREAM mode if that fails.
Signed-off-by: Jeff Hansen <x@...fhansen.com>
---
net/unix/Kconfig | 10 +++++
net/unix/af_unix.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 123 insertions(+), 0 deletions(-)
diff --git a/net/unix/Kconfig b/net/unix/Kconfig
index 5a69733..68df4f1 100644
--- a/net/unix/Kconfig
+++ b/net/unix/Kconfig
@@ -19,3 +19,13 @@ config UNIX
Say Y unless you know what you are doing.
+config UNIX_FOPS
+ boolean "Allow Unix sockets to be treated like normal files"
+ depends on UNIX
+ ---help---
+ If you say Y here, Unix sockets may be opened, written, read, and
+ closed, like normal files. This is handy for sending short commands
+ to Unix sockets (i.e. from shell scripts), without having to create
+ a Unix socket.
+
+ Say Y unless you know what you are doing.
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 0ebc777..b5a6655 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -798,6 +798,114 @@ fail:
return NULL;
}
+#ifdef CONFIG_UNIX_FOPS
+static int unix_open(struct inode *inode, struct file *filp)
+{
+ int err;
+ struct socket *sock = NULL;
+ struct dentry *dentry = filp->f_dentry;
+ struct sockaddr_un sunaddr = { 0 };
+ char *p;
+
+ if (!filp)
+ return -ENXIO;
+ dentry = filp->f_dentry;
+
+ if (!dentry || !dentry->d_parent)
+ return -ENXIO;
+
+ if (filp->private_data)
+ return -EBUSY;
+
+ sunaddr.sun_family = AF_UNIX;
+ p = d_path(&filp->f_path, sunaddr.sun_path, sizeof(sunaddr.sun_path));
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+ memmove(sunaddr.sun_path, p, p[sizeof(sunaddr.sun_path) - 1] ?
+ sizeof(sunaddr.sun_path) : strlen(p));
+
+ err = sock_create(PF_UNIX, SOCK_DGRAM, 0, &sock);
+ if (err)
+ return err;
+
+ err = unix_dgram_connect(sock, (struct sockaddr *)&sunaddr,
+ sizeof(sunaddr), 0);
+ if (err) {
+ sock_release(sock);
+
+ err = sock_create(PF_UNIX, SOCK_STREAM, 0, &sock);
+ if (err)
+ return err;
+
+ err = unix_stream_connect(sock, (struct sockaddr *)&sunaddr,
+ sizeof(sunaddr), 0);
+
+ if (err)
+ return err;
+ }
+ filp->private_data = sock;
+
+ return err;
+}
+
+static int unix_frelease(struct inode *inode, struct file *filp)
+{
+ if (!filp->private_data)
+ return -ENXIO;
+
+ sock_release(filp->private_data);
+ filp->private_data = NULL;
+ return 0;
+}
+
+static ssize_t unix_readwrite(struct file *filp, void *buf,
+ size_t _len, loff_t *ppos, int do_write)
+{
+ struct socket *sock = filp->private_data;
+ int len = (int)_len, err;
+ struct kvec iov = {
+ .iov_base = buf,
+ .iov_len = len,
+ };
+ struct msghdr msg = {
+ /* NB: struct iovec and kvec are equal */
+ .msg_iov = (struct iovec *)&iov,
+ .msg_iovlen = 1,
+ };
+
+ if (!sock)
+ return -ENXIO;
+ if (_len > 0xffffffffLL)
+ return -E2BIG;
+
+ err = do_write ? sock_sendmsg(sock, &msg, len) :
+ sock_recvmsg(sock, &msg, len, 0);
+ if (err > 0 && ppos)
+ *ppos += err;
+
+ return err;
+}
+
+static ssize_t unix_write(struct file *filp, const char __user *buf,
+ size_t _len, loff_t *ppos)
+{
+ return unix_readwrite(filp, (void *)buf, _len, ppos, 0);
+}
+
+static ssize_t unix_read(struct file *filp, const char __user *buf,
+ size_t _len, loff_t *ppos)
+{
+ return unix_readwrite(filp, (void *)buf, _len, ppos, 0);
+}
+
+const struct file_operations unix_sock_fops = {
+ .owner = THIS_MODULE,
+ .open = unix_open,
+ .release = unix_frelease,
+ .write = unix_write,
+ .read = unix_read,
+};
+#endif /* CONFIG_UNIX_FOPS */
static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
@@ -874,6 +982,11 @@ out_mknod_drop_write:
mnt_drop_write(nd.path.mnt);
if (err)
goto out_mknod_dput;
+
+#ifdef CONFIG_UNIX_FOPS
+ dentry->d_inode->i_fop = &unix_sock_fops;
+#endif
+
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
dput(nd.path.dentry);
nd.path.dentry = dentry;
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists