tcp/udp recvfrom does not set address if return == 0

Assar Westerlund (assar@sics.se)
05 Jul 1999 21:36:57 +0200

If you're doing recvfrom(socket, buf, len, flags, from, from_len) and
the return value is zero, from_len gets set but the address isn't
copied into from.

The following patch only sets from_len if the address is also copied
to from and (for the TCP-case) also does it return value == 0.

/assar

--- net/ipv4/tcp.c.orig Mon Jul 5 20:57:57 1999
+++ net/ipv4/tcp.c Mon Jul 5 20:58:16 1999
@@ -1306,12 +1306,12 @@
break;
}

- if(copied > 0 && msg->msg_name)
+ if(copied >= 0 && msg->msg_name) {
tp->af_specific->addr2sockaddr(sk, (struct sockaddr *)
msg->msg_name);
-
if(addr_len)
*addr_len = tp->af_specific->sockaddr_len;
+ }

remove_wait_queue(sk->sleep, &wait);
current->state = TASK_RUNNING;
--- net/ipv4/udp.c.orig Mon Jul 5 20:57:59 1999
+++ net/ipv4/udp.c Mon Jul 5 20:59:08 1999
@@ -862,12 +862,6 @@
struct sk_buff *skb;
int copied, err;

- /*
- * Check any passed addresses
- */
- if (addr_len)
- *addr_len=sizeof(*sin);
-
if (flags & MSG_ERRQUEUE)
return ip_recv_error(sk, msg, len);

@@ -918,6 +912,12 @@
/* Copy the address. */
if (sin)
{
+ /*
+ * Check any passed addresses
+ */
+ if (addr_len)
+ *addr_len=sizeof(*sin);
+
sin->sin_family = AF_INET;
sin->sin_port = skb->h.uh->source;
sin->sin_addr.s_addr = skb->nh.iph->saddr;

-
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