lkml.org 
[lkml]   [2001]   [Jul]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: recvfrom and sockaddr_in.sin_port
From
Date
Adam <adam@eax.com> writes:
>
> and as show in above example and other repeated test, the port
> part is always set to 0. Shouldn't that be set to port number?

SOCK_RAW has no ports, so no.

>
> on similar token the "padding" part after the IP is always set
> to the same pattern. Shouldn't it rather be zeroed, or be
> some random data?

It should stay at the old value or alternatively be zeroed. That's a
kernel bug.

Here is a patch that implements the first alternative. David, please consider
applying.

diff -burp linux/include/linux/in.h linux-work/include/linux/in.h
--- linux/include/linux/in.h Thu Jul 5 13:18:27 2001
+++ linux-work/include/linux/in.h Sun Jul 8 19:05:30 2001
@@ -109,6 +109,10 @@ struct in_pktinfo
};

/* Structure describing an Internet (IP) socket address. */
+/* Note here and in others places is the assumption made that there
+ are no holes in in this structure. This is ok for all architectures
+ which layout structures members at worst to their natural
+ alignment. -AK */
#define __SOCK_SIZE__ 16 /* sizeof(struct sockaddr) */
struct sockaddr_in {
sa_family_t sin_family; /* Address family */
@@ -119,7 +123,7 @@ struct sockaddr_in {
unsigned char __pad[__SOCK_SIZE__ - sizeof(short int) -
sizeof(unsigned short int) - sizeof(struct in_addr)];
};
-#define sin_zero __pad /* for BSD UNIX comp. -FvK */
+#define sin_zero __pad


/*
diff -burp linux/net/ipv4/af_inet.c linux-work/net/ipv4/af_inet.c
--- linux/net/ipv4/af_inet.c Wed Jul 4 17:21:32 2001
+++ linux-work/net/ipv4/af_inet.c Sun Jul 8 19:05:31 2001
@@ -729,7 +729,7 @@ static int inet_getname(struct socket *s
sin->sin_port = sk->sport;
sin->sin_addr.s_addr = addr;
}
- *uaddr_len = sizeof(*sin);
+ *uaddr_len = sizeof(offsetof(struct sockaddr_in, sin_zero));
return(0);
}

diff -burp linux/net/ipv4/raw.c linux-work/net/ipv4/raw.c
--- linux/net/ipv4/raw.c Wed Jul 4 17:21:32 2001
+++ linux-work/net/ipv4/raw.c Sun Jul 8 19:06:10 2001
@@ -493,7 +493,7 @@ int raw_recvmsg(struct sock *sk, struct
goto out;

if (addr_len)
- *addr_len = sizeof(*sin);
+ *addr_len = offsetof(struct sockaddr_in, sin_zero);

if (flags & MSG_ERRQUEUE) {
err = ip_recv_error(sk, msg, len);
diff -burp linux/net/ipv4/udp.c linux-work/net/ipv4/udp.c
--- linux/net/ipv4/udp.c Thu Apr 12 21:11:39 2001
+++ linux-work/net/ipv4/udp.c Sun Jul 8 19:05:31 2001
@@ -635,7 +635,7 @@ int udp_recvmsg(struct sock *sk, struct
* Check any passed addresses
*/
if (addr_len)
- *addr_len=sizeof(*sin);
+ *addr_len=offsetof(struct sockaddr_in, sin_zero);

if (flags & MSG_ERRQUEUE)
return ip_recv_error(sk, msg, len);

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:56    [W:1.426 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site