From owner-svn-src-head@FreeBSD.ORG Wed Oct 21 23:50:35 2009 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DDF53106566C; Wed, 21 Oct 2009 23:50:35 +0000 (UTC) (envelope-from philip@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id CC38C8FC12; Wed, 21 Oct 2009 23:50:35 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id n9LNoZ2O013747; Wed, 21 Oct 2009 23:50:35 GMT (envelope-from philip@svn.freebsd.org) Received: (from philip@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id n9LNoZ79013743; Wed, 21 Oct 2009 23:50:35 GMT (envelope-from philip@svn.freebsd.org) Message-Id: <200910212350.n9LNoZ79013743@svn.freebsd.org> From: Philip Paeps Date: Wed, 21 Oct 2009 23:50:35 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r198352 - head/sbin/dhclient X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Oct 2009 23:50:36 -0000 Author: philip Date: Wed Oct 21 23:50:35 2009 New Revision: 198352 URL: http://svn.freebsd.org/changeset/base/198352 Log: Make dhclient use bootpc (68) as the source port for unicast DHCPREQUEST packets instead of allowing the protocol stack to pick a random source port. This fixes the behaviour where dhclient would never transition from RENEWING to BOUND without going through REBINDING in networks which are paranoid about DHCP spoofing, such as most mainstream cable-broadband ISP networks. Reviewed by: brooks Obtained from: OpenBSD (partly - I'm not convinced their solution can work) MFC after: 1 week (pending re approval) Modified: head/sbin/dhclient/bpf.c head/sbin/dhclient/dhcpd.h head/sbin/dhclient/packet.c Modified: head/sbin/dhclient/bpf.c ============================================================================== --- head/sbin/dhclient/bpf.c Wed Oct 21 20:59:12 2009 (r198351) +++ head/sbin/dhclient/bpf.c Wed Oct 21 23:50:35 2009 (r198352) @@ -90,11 +90,23 @@ if_register_bpf(struct interface_info *i void if_register_send(struct interface_info *info) { + int sock, on = 1; + /* * If we're using the bpf API for sending and receiving, we * don't need to register this interface twice. */ info->wfdesc = info->rfdesc; + + /* + * Use raw socket for unicast send. + */ + if ((sock = socket(AF_INET, SOCK_RAW, IPPROTO_UDP)) == -1) + error("socket(SOCK_RAW): %m"); + if (setsockopt(sock, IPPROTO_IP, IP_HDRINCL, &on, + sizeof(on)) == -1) + error("setsockopt(IP_HDRINCL): %m"); + info->ufdesc = sock; } /* @@ -244,35 +256,32 @@ send_packet(struct interface_info *inter { unsigned char buf[256]; struct iovec iov[2]; + struct msghdr msg; int result, bufp = 0; - int sock; - - if (to->sin_addr.s_addr != INADDR_BROADCAST) { - note("SENDING DIRECT"); - /* We know who the server is, send the packet via - normal socket interface */ - - if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) >= 0) { - result = sendto (sock, (char *)raw, len, 0, - (struct sockaddr *)to, sizeof *to); - close(sock); - if (result > 0) - return result; - } - } /* Assemble the headers... */ - assemble_hw_header(interface, buf, &bufp, hto); + if (to->sin_addr.s_addr == INADDR_BROADCAST) + assemble_hw_header(interface, buf, &bufp, hto); assemble_udp_ip_header(buf, &bufp, from.s_addr, to->sin_addr.s_addr, to->sin_port, (unsigned char *)raw, len); - /* Fire it off */ iov[0].iov_base = (char *)buf; iov[0].iov_len = bufp; iov[1].iov_base = (char *)raw; iov[1].iov_len = len; - result = writev(interface->wfdesc, iov, 2); + /* Fire it off */ + if (to->sin_addr.s_addr == INADDR_BROADCAST) + result = writev(interface->wfdesc, iov, 2); + else { + memset(&msg, 0, sizeof(msg)); + msg.msg_name = (struct sockaddr *)to; + msg.msg_namelen = sizeof(*to); + msg.msg_iov = iov; + msg.msg_iovlen = 2; + result = sendmsg(interface->ufdesc, &msg, 0); + } + if (result < 0) warning("send_packet: %m"); return (result); Modified: head/sbin/dhclient/dhcpd.h ============================================================================== --- head/sbin/dhclient/dhcpd.h Wed Oct 21 20:59:12 2009 (r198351) +++ head/sbin/dhclient/dhcpd.h Wed Oct 21 23:50:35 2009 (r198352) @@ -37,6 +37,8 @@ * Enterprises. To learn more about the Internet Software Consortium, * see ``http://www.vix.com/isc''. To learn more about Vixie * Enterprises, see ``http://www.vix.com''. + * + * $FreeBSD$ */ #include @@ -194,6 +196,7 @@ struct interface_info { char name[IFNAMSIZ]; int rfdesc; int wfdesc; + int ufdesc; unsigned char *rbuf; size_t rbuf_max; size_t rbuf_offset; Modified: head/sbin/dhclient/packet.c ============================================================================== --- head/sbin/dhclient/packet.c Wed Oct 21 20:59:12 2009 (r198351) +++ head/sbin/dhclient/packet.c Wed Oct 21 23:50:35 2009 (r198352) @@ -135,6 +135,17 @@ assemble_udp_ip_header(unsigned char *bu ip.ip_dst.s_addr = to; ip.ip_sum = wrapsum(checksum((unsigned char *)&ip, sizeof(ip), 0)); + + /* + * While the BPF -- used for broadcasts -- expects a "true" IP header + * with all the bytes in network byte order, the raw socket interface + * which is used for unicasts expects the ip_len field to be in host + * byte order. In both cases, the checksum has to be correct, so this + * is as good a place as any to turn the bytes around again. + */ + if (to != INADDR_BROADCAST) + ip.ip_len = ntohs(ip.ip_len); + memcpy(&buf[*bufix], &ip, sizeof(ip)); *bufix += sizeof(ip);