busybox: add support for CHECKSUM_PARTIAL to udhcpc

When running as KVM or Xen guest, packets may be received with
incomplete checksum[1].  Patch adopted from Fedora dhcp package.

[1]. http://article.gmane.org/gmane.linux.kernel/1003853

Signed-off-by: Alexey I. Froloff <raorn@raorn.name>
SVN-Revision: 33475

diff --git a/package/busybox/Makefile b/package/busybox/Makefile
index 76f52fcd345e72ac95081a1a1c8fd28011e35153..6352eec523cd26b7179470199eec2c0a1a9fb748 100644 (file)
--- a/package/busybox/Makefile
+++ b/package/busybox/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=busybox
 PKG_VERSION:=1.19.4
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 PKG_FLAGS:=essential
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2

diff --git a/package/busybox/patches/950-partial-checksum.patch b/package/busybox/patches/950-partial-checksum.patch
new file mode 100644 (file)
index 0000000..e595162
--- /dev/null
+++ b/package/busybox/patches/950-partial-checksum.patch
@@ -0,0 +1,87 @@
+diff -ur busybox-1.19.4.orig/networking/udhcp/dhcpc.c busybox-1.19.4/networking/udhcp/dhcpc.c
+--- busybox-1.19.4.orig/networking/udhcp/dhcpc.c       2012-09-06 22:33:53.476998721 +0400
++++ busybox-1.19.4/networking/udhcp/dhcpc.c    2012-09-07 01:09:46.693372304 +0400
+@@ -26,8 +26,8 @@
+ #include "dhcpc.h"
+ 
+ #include <netinet/if_ether.h>
+-#include <netpacket/packet.h>
+ #include <linux/filter.h>
++#include <linux/if_packet.h>
+ 
+ /* struct client_config_t client_config is in bb_common_bufsiz1 */
+ 
+@@ -784,17 +784,41 @@
+ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
+ {
+       int bytes;
++      int nocsum = 0;
+       struct ip_udp_dhcp_packet packet;
+       uint16_t check;
++      unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
++      struct iovec iov = {
++              .iov_base = &packet,
++              .iov_len = sizeof(packet),
++      };
++      struct msghdr msg = {
++              .msg_iov = &iov,
++              .msg_iovlen = 1,
++              .msg_control = cmsgbuf,
++              .msg_controllen = sizeof(cmsgbuf),
++      };
++      struct cmsghdr *cmsg;
+ 
+       memset(&packet, 0, sizeof(packet));
+-      bytes = safe_read(fd, &packet, sizeof(packet));
++      do {
++              bytes = recvmsg(fd, &msg, 0);
++      } while (bytes < 0 && errno == EINTR);
++
+       if (bytes < 0) {
+               log1("Packet read error, ignoring");
+               /* NB: possible down interface, etc. Caller should pause. */
+               return bytes; /* returns -1 */
+       }
+ 
++      for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
++              if (cmsg->cmsg_level == SOL_PACKET &&
++                      cmsg->cmsg_type == PACKET_AUXDATA) {
++                      struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
++                      nocsum = aux->tp_status & TP_STATUS_CSUMNOTREADY;
++              }
++      }
++
+       if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
+               log1("Packet is too short, ignoring");
+               return -2;
+@@ -834,7 +858,7 @@
+       packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
+       check = packet.udp.check;
+       packet.udp.check = 0;
+-      if (check && check != udhcp_checksum(&packet, bytes)) {
++      if (!nocsum && check && check != udhcp_checksum(&packet, bytes)) {
+               log1("Packet with bad UDP checksum received, ignoring");
+               return -2;
+       }
+@@ -880,6 +904,7 @@
+ {
+       int fd;
+       struct sockaddr_ll sock;
++      int val;
+ 
+       /*
+        * Comment:
+@@ -946,6 +971,13 @@
+                       log1("Attached filter to raw socket fd %d", fd); // log?
+       }
+ 
++      val = 1;
++      if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, &val,
++                      sizeof(val)) < 0) {
++              if (errno != ENOPROTOOPT)
++                      log1("Failed to set auxiliary packet data for socket fd %d", fd);
++      }
++
+       log1("Created raw socket");
+ 
+       return fd;