diff options
| -rw-r--r-- | usr.sbin/ppp/alias.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/usr.sbin/ppp/alias.c b/usr.sbin/ppp/alias.c index fa58cdc..5a99fb9 100644 --- a/usr.sbin/ppp/alias.c +++ b/usr.sbin/ppp/alias.c @@ -754,10 +754,13 @@ void PacketAliasIn(pip) struct ip *pip; { - struct in_addr save_address; + int checksum_ok; -/* Save initial destination address */ - save_address = pip->ip_dst; +/* Verify initial checksum */ + if (IpChecksum(pip) == 0) + checksum_ok = 1; + else + checksum_ok = 0; if ( (ntohs(pip->ip_off) & IP_OFFMASK) == 0 ) { @@ -787,8 +790,8 @@ struct ip *pip; FragmentIn(pip); } -/* If destination address has changed, adjust IP checksum */ - if (pip->ip_dst.s_addr != save_address.s_addr) +/* adjust IP checksum, if original is correct */ + if (checksum_ok == 1) { pip->ip_sum = 0; pip->ip_sum = IpChecksum(pip); @@ -799,9 +802,13 @@ void PacketAliasOut(pip) struct ip *pip; { - struct in_addr save_address; + int checksum_ok; + + if (IpChecksum(pip) == 0) + checksum_ok = 1; + else + checksum_ok = 0; - save_address = pip->ip_src; if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0) { switch (pip->ip_p) @@ -819,14 +826,12 @@ struct ip *pip; } else { - if (pip->ip_src.s_addr != GetAliasAddress().s_addr) - FragmentOut(pip); + FragmentOut(pip); } -/* Adjust IP checksum if source address has been aliased */ - if (pip->ip_src.s_addr != save_address.s_addr) +/* Adjust IP checksum, if original is correct */ + if (checksum_ok == 1) { - pip->ip_sum = 0; pip->ip_sum = IpChecksum(pip); } |
