From ce6055583f7b8b4af7175b777b023bc115aed382 Mon Sep 17 00:00:00 2001 From: Julien BLACHE Date: Tue, 10 Aug 2010 15:37:10 +0200 Subject: [PATCH] ipconfig: differentiate between error and non-DHCP/BOOTP traffic in packet_recv() Commit 4efbcf90f60e27febe883ef052454d8cfded5c15 badly broke ipconfig by turning packet_recv() into an all-or-nothing function. Before this commit, packet_recv() did distinguish between a DHCP/BOOTP packet that's of interest, random UDP packets we don't care about and errors. After the patch, either a packet is a DHCP/BOOTP packet or packet_recv() exits with an error. This breaks ipconfig on big, noisy LANs where random UDP traffic can arrive before the DHCP reply and throw the device into DEVST_ERROR state. --- usr/kinit/ipconfig/bootp_proto.c | 2 +- usr/kinit/ipconfig/dhcp_proto.c | 4 ++-- usr/kinit/ipconfig/packet.c | 5 +++-- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/usr/kinit/ipconfig/bootp_proto.c b/usr/kinit/ipconfig/bootp_proto.c index 42dfad3..baf9d3e 100644 --- a/usr/kinit/ipconfig/bootp_proto.c +++ b/usr/kinit/ipconfig/bootp_proto.c @@ -171,7 +171,7 @@ int bootp_recv_reply(struct netdev *dev) ret = packet_recv(iov, 3); if (ret <= 0) - return -1; + return ret; if (ret < sizeof(struct bootp_hdr) || bootp.op != BOOTP_REPLY || /* RFC951 7.5 */ diff --git a/usr/kinit/ipconfig/dhcp_proto.c b/usr/kinit/ipconfig/dhcp_proto.c index 2a2651a..fc0494d 100644 --- a/usr/kinit/ipconfig/dhcp_proto.c +++ b/usr/kinit/ipconfig/dhcp_proto.c @@ -148,8 +148,8 @@ static int dhcp_recv(struct netdev *dev) int ret; ret = packet_recv(iov, 3); - if (ret == 0) - return -1; + if (ret <= 0) + return ret; dprintf("\n dhcp xid %08x ", dev->bootp.xid); diff --git a/usr/kinit/ipconfig/packet.c b/usr/kinit/ipconfig/packet.c index 508c7ba..d0e143a 100644 --- a/usr/kinit/ipconfig/packet.c +++ b/usr/kinit/ipconfig/packet.c @@ -214,7 +214,8 @@ void packet_discard(void) * Receive a bootp packet. The options are listed in iov[1...iov_len]. * iov[0] must point to the bootp packet header. * Returns: - * 0 = Error, try again later + * -1 = Error, try again later +* 0 = Discarded packet (non-DHCP/BOOTP traffic) * >0 = Size of packet */ int packet_recv(struct iovec *iov, int iov_len) @@ -235,7 +236,7 @@ int packet_recv(struct iovec *iov, int iov_len) ret = recvfrom(pkt_fd, &iph, sizeof(struct iphdr), MSG_PEEK, NULL, NULL); if (ret == -1) - return 0; + return -1; if (iph.ihl < 5 || iph.version != IPVERSION) goto discard_pkt; -- 1.5.6.5