Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 8 Jul 2001 15:28:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 8 Jul 2001 15:28:42 -0400 Received: from ns.suse.de ([213.95.15.193]:8719 "HELO Cantor.suse.de") by vger.kernel.org with SMTP id ; Sun, 8 Jul 2001 15:28:28 -0400 Subject: Re: recvfrom and sockaddr_in.sin_port From: Andi Kleen Cc: linux-kernel@vger.kernel.org, davem@redhat.com User-Agent: Gnus/5.0803 (Gnus v5.8.3) Emacs/20.7 Date: 08 Jul 2001 21:28:27 +0200 In-Reply-To: Adam's message of "8 Jul 2001 18:23:35 +0200" Message-ID: Lines: 80 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: unlisted-recipients:; (no To-header on input)@localhost.localdomain Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Adam 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/