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get receiving interface index while no message is received

PATCH In review Yang Hongyang 3 participants 5 messages Aug 8, 2008 – Aug 18, 2008

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Yang Hongyang

author
#0 lore raw

when I use getsockopt(sk, IPPROTO_IPV6, IPV6_2292PKTOPTIONS,(char *)incmsg, &cnt) to get receiving interface index while no message is received,

What interface index should be returned?

author
#1 lore raw

PATCH 1/1 IPv6:fix the return interface index when get it while no message is received

Quoted 4 lines · Yang Hongyang

when I use getsockopt(sk, IPPROTO_IPV6, IPV6_2292PKTOPTIONS,(char *)incmsg, &cnt) to get receiving interface index while no message is received,

What interface index should be returned?

When get receiving interface index while no message is received, the bounded device's index of the socket should be returned?

Signed-off-by Yang Hongyang<[email protected]>
ipv6_sockglue.c +2 -2
@@ -911,7 +911,7 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 		} else {
 			if (np->rxopt.bits.rxinfo) {
 				struct in6_pktinfo src_info;
-				src_info.ipi6_ifindex = np->mcast_oif;
+				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif : sk->sk_bound_dev_if;
 				ipv6_addr_copy(&src_info.ipi6_addr, &np->daddr);
 				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 			}

@@ -921,7 +921,7 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 			}
 			if (np->rxopt.bits.rxoinfo) {
 				struct in6_pktinfo src_info;
-				src_info.ipi6_ifindex = np->mcast_oif;
+				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif : sk->sk_bound_dev_if;
 				ipv6_addr_copy(&src_info.ipi6_addr, &np->daddr);
 				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 			}
Signature · 1 line
1.5.3.8
maintainer
#2 lore raw

Re: [PATCH] IPv6:fix the return interface index when get it while no message is received

From: Yang Hongyang <[email protected]>
Date: Fri, 08 Aug 2008 13:59:54 +0800

Quoted 10 lines
Quoted 4 lines · Yang Hongyang

when I use getsockopt(sk, IPPROTO_IPV6, IPV6_2292PKTOPTIONS,(char *)incmsg, &cnt) to get receiving interface index while no message is received,

What interface index should be returned?

When get receiving interface index while no message is received, the bounded device's index of the socket should be returned?

Signed-off-by Yang Hongyang<[email protected]>

To me it seems to be an undefined operation.

One cannot expect something valid from this socket option until a packet really is received on the socket.

#3 lore raw

Re: [PATCH] IPv6:fix the return interface index when get it while no message is received

Quoted 11 lines · David Miller

From: Yang Hongyang <[email protected]>
Date: Fri, 08 Aug 2008 13:59:54 +0800

Quoted 8 lines
Quoted 4 lines · Yang Hongyang

when I use getsockopt(sk, IPPROTO_IPV6, IPV6_2292PKTOPTIONS,(char *)incmsg, &cnt) to get receiving interface index while no message is received,

What interface index should be returned?

When get receiving interface index while no message is received, the bounded device's index of the socket should be returned?

Quoted 6 lines
Quoted 1 line
Signed-off-by Yang Hongyang<[email protected]>

To me it seems to be an undefined operation.

One cannot expect something valid from this socket option until a packet really is received on the socket.

Here is what 2292 has to say:

Quoted 4 lines

The corresponding receive option

       getsockopt(fd, IPPROTO_IPV6, IPV6_PKTOPTIONS, &buf, &len);
Quoted 10 lines

returns a buffer with one or more ancillary data objects for all the optional receive information that the application has previously specified that it wants to receive. The fourth argument points to the buffer that is filled in by the call. The fifth argument is a pointer to a value-result integer: when the function is called the integer specifies the size of the buffer pointed to by the fourth argument, and on return this integer contains the actual number of bytes that were returned. The application processes this buffer exactly as if the buffer were returned by recvmsg() as control information.

So, there return value should be any sticky options set.

In the case of PKTINFO, the interface should be either 0 or the one set by the sticky option.

The address should be should be from the options or IN6ADDR_ANY.

This is all for RFC2292 style.

For RFC 3542 style, there what should be done:

Issuing getsockopt() for the above options will return the sticky option value i.e., the value set with setsockopt(). If no sticky option value has been set getsockopt() will return the following values:

- For the IPV6_PKTINFO option, it will return an in6_pktinfo structure with ipi6_addr being in6addr_any and ipi6_ifindex being zero.

-vlad

maintainer
#4 lore raw

Re: [PATCH] IPv6:fix the return interface index when get it while no message is received

From: Vlad Yasevich <[email protected]>
Date: Fri, 08 Aug 2008 10:58:04 -0400

Quoted 10 lines

For RFC 3542 style, there what should be done:

Issuing getsockopt() for the above options will return the sticky option value i.e., the value set with setsockopt(). If no sticky option value has been set getsockopt() will return the following values:

- For the IPV6_PKTINFO option, it will return an in6_pktinfo structure with ipi6_addr being in6addr_any and ipi6_ifindex being zero.

Ok so it looks like Yang's patch is ok.

Yank please resubmit your patch, thank you.