[PATCH 07/11] uml: fix mcast network driver error handling

From: Paolo 'Blaisorblade' Giarrusso
Date: Tue Oct 25 2005 - 17:09:01 EST


From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>

printk clears the host errno (I verified this in debugging and it's reasonable
enough, given that it ends via a write call on some fd, especially since
printk() goes on /dev/tty0 which is often the host stdout).
So save errno earlier. There's no reason to change the printk calls to use -err
rather than errno - the assignment can't clear errno.

And in the first failure path, we used to return 0 too (and this time more
clearly), which is totally wrong. 0 is a success fd, which is then registered
and gives a "registering fd twice" warning.

Finally, fix up some whitespace.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>
---

arch/um/drivers/mcast_user.c | 20 ++++++++++----------
1 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/um/drivers/mcast_user.c b/arch/um/drivers/mcast_user.c
--- a/arch/um/drivers/mcast_user.c
+++ b/arch/um/drivers/mcast_user.c
@@ -54,7 +54,7 @@ static int mcast_open(void *data)
struct mcast_data *pri = data;
struct sockaddr_in *sin = pri->mcast_addr;
struct ip_mreq mreq;
- int fd, yes = 1, err = 0;
+ int fd, yes = 1, err = -EINVAL;


if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0))
@@ -63,40 +63,40 @@ static int mcast_open(void *data)
fd = socket(AF_INET, SOCK_DGRAM, 0);

if (fd < 0){
+ err = -errno;
printk("mcast_open : data socket failed, errno = %d\n",
errno);
- err = -errno;
goto out;
}

if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+ err = -errno;
printk("mcast_open: SO_REUSEADDR failed, errno = %d\n",
errno);
- err = -errno;
goto out_close;
}

/* set ttl according to config */
if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
sizeof(pri->ttl)) < 0) {
+ err = -errno;
printk("mcast_open: IP_MULTICAST_TTL failed, error = %d\n",
errno);
- err = -errno;
goto out_close;
}

/* set LOOP, so data does get fed back to local sockets */
if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
+ err = -errno;
printk("mcast_open: IP_MULTICAST_LOOP failed, error = %d\n",
errno);
- err = -errno;
goto out_close;
}

/* bind socket to mcast address */
if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) {
- printk("mcast_open : data bind failed, errno = %d\n", errno);
err = -errno;
+ printk("mcast_open : data bind failed, errno = %d\n", errno);
goto out_close;
}

@@ -105,22 +105,22 @@ static int mcast_open(void *data)
mreq.imr_interface.s_addr = 0;
if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP,
&mreq, sizeof(mreq)) < 0) {
+ err = -errno;
printk("mcast_open: IP_ADD_MEMBERSHIP failed, error = %d\n",
errno);
printk("There appears not to be a multicast-capable network "
"interface on the host.\n");
printk("eth0 should be configured in order to use the "
"multicast transport.\n");
- err = -errno;
- goto out_close;
+ goto out_close;
}

return fd;

out_close:
- os_close_file(fd);
+ os_close_file(fd);
out:
- return err;
+ return err;
}

static void mcast_close(int fd, void *data)

-
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