package/busybox/patches/950-partial-checksum.patch

   1 diff -ur busybox-1.19.4.orig/networking/udhcp/dhcpc.c busybox-1.19.4/networking/udhcp/dhcpc.c
   2 --- busybox-1.19.4.orig/networking/udhcp/dhcpc.c        2012-09-06 22:33:53.476998721 +0400
   3 +++ busybox-1.19.4/networking/udhcp/dhcpc.c     2012-09-07 01:09:46.693372304 +0400
   4 @@ -26,8 +26,8 @@
   5  #include "dhcpc.h"
   6
   7  #include <netinet/if_ether.h>
   8 -#include <netpacket/packet.h>
   9  #include <linux/filter.h>
  10 +#include <linux/if_packet.h>
  11
  12  /* struct client_config_t client_config is in bb_common_bufsiz1 */
  13
  14 @@ -784,17 +784,41 @@
  15  static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
  16  {
  17         int bytes;
  18 +       int nocsum = 0;
  19         struct ip_udp_dhcp_packet packet;
  20         uint16_t check;
  21 +       unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
  22 +       struct iovec iov = {
  23 +               .iov_base = &packet,
  24 +               .iov_len = sizeof(packet),
  25 +       };
  26 +       struct msghdr msg = {
  27 +               .msg_iov = &iov,
  28 +               .msg_iovlen = 1,
  29 +               .msg_control = cmsgbuf,
  30 +               .msg_controllen = sizeof(cmsgbuf),
  31 +       };
  32 +       struct cmsghdr *cmsg;
  33
  34         memset(&packet, 0, sizeof(packet));
  35 -       bytes = safe_read(fd, &packet, sizeof(packet));
  36 +       do {
  37 +               bytes = recvmsg(fd, &msg, 0);
  38 +       } while (bytes < 0 && errno == EINTR);
  39 +
  40         if (bytes < 0) {
  41                 log1("Packet read error, ignoring");
  42                 /* NB: possible down interface, etc. Caller should pause. */
  43                 return bytes; /* returns -1 */
  44         }
  45
  46 +       for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
  47 +               if (cmsg->cmsg_level == SOL_PACKET &&
  48 +                       cmsg->cmsg_type == PACKET_AUXDATA) {
  49 +                       struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
  50 +                       nocsum = aux->tp_status & TP_STATUS_CSUMNOTREADY;
  51 +               }
  52 +       }
  53 +
  54         if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
  55                 log1("Packet is too short, ignoring");
  56                 return -2;
  57 @@ -834,7 +858,7 @@
  58         packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
  59         check = packet.udp.check;
  60         packet.udp.check = 0;
  61 -       if (check && check != udhcp_checksum(&packet, bytes)) {
  62 +       if (!nocsum && check && check != udhcp_checksum(&packet, bytes)) {
  63                 log1("Packet with bad UDP checksum received, ignoring");
  64                 return -2;
  65         }
  66 @@ -880,6 +904,7 @@
  67  {
  68         int fd;
  69         struct sockaddr_ll sock;
  70 +       int val;
  71
  72         /*
  73          * Comment:
  74 @@ -946,6 +971,13 @@
  75                         log1("Attached filter to raw socket fd %d", fd); // log?
  76         }
  77
  78 +       val = 1;
  79 +       if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, &val,
  80 +                       sizeof(val)) < 0) {
  81 +               if (errno != ENOPROTOOPT)
  82 +                       log1("Failed to set auxiliary packet data for socket fd %d", fd);
  83 +       }
  84 +
  85         log1("Created raw socket");
  86
  87         return fd;